International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Design and Implementation of Polyphase based Subband Adaptive Structure for N...Pratik Ghotkar
With the tremendous growth in the Digital Signal processing technology, there are many techniques available to remove noise from the speech signals which is used in the speech processing. Widely used LMS algorithm is modified with much advancement but still there are many limitations are introducing. This paper consist of a new approach i.e. subband adaptive processing for noise cancelation in the speech signals. Subband processing employs the multirate signal processing. The polyphase based subband adaptive implementation finds better results in term of MMSE , PSNR and processing time; also the synthesis filter bank is works on the lower data rate which reduces the computational Burdon as compare to the direct implementation of Subband adaptive filter. The normalized least mean squares (NLMS) algorithm is a class of adaptive filter used.
Performance Analysis of Noise Uncertainty in Energy Detection Spectrum Sensin...Onyebuchi nosiri
Abstract—The Performance of Energy Detection (ED) spectrum sensing technique depends on threshold selected for deciding the presence or absence of Primary User. In practice, noise density is uncertain and can affect the performance of ED in that sometimes presence of signals is confused for their absence (noise) and vice versa. The traditional energy detection algorithm was based on fixed threshold and has been observed to be inefficient under noise uncertainty. The technique requires optimizing the threshold to be more flexible to check the noise uncertainty effects. The paper therefore proposed an algorithm relative to a unique environment which in effect considered the dynamism relatively and dependent on the environment. The results obtained demonstrated significant improvement compared to the traditional energy detection system
Audio compression has become one of the basic technologies of the multimedia age. The change in the telecommunication infrastructure, in recent years, from circuit switched to packet switched systems has also reflected on the way that speech and audio signals are carried in present systems. In many applications, such as the design of multimedia workstations and high quality audio transmission and storage, the goal is to achieve transparent coding of audio and speech signals at the lowest possible data rates. In other words, bandwidth cost money, therefore, the transmission and storage of information becomes costly. However, if we can use less data, both transmission and storage become cheaper. Further reduction in bit rate is an attractive proposition in applications like remote broadcast lines, studio links, satellite transmission of high quality audio and voice over internet.
Design and Implementation of Polyphase based Subband Adaptive Structure for N...Pratik Ghotkar
With the tremendous growth in the Digital Signal processing technology, there are many techniques available to remove noise from the speech signals which is used in the speech processing. Widely used LMS algorithm is modified with much advancement but still there are many limitations are introducing. This paper consist of a new approach i.e. subband adaptive processing for noise cancelation in the speech signals. Subband processing employs the multirate signal processing. The polyphase based subband adaptive implementation finds better results in term of MMSE , PSNR and processing time; also the synthesis filter bank is works on the lower data rate which reduces the computational Burdon as compare to the direct implementation of Subband adaptive filter. The normalized least mean squares (NLMS) algorithm is a class of adaptive filter used.
Performance Analysis of Noise Uncertainty in Energy Detection Spectrum Sensin...Onyebuchi nosiri
Abstract—The Performance of Energy Detection (ED) spectrum sensing technique depends on threshold selected for deciding the presence or absence of Primary User. In practice, noise density is uncertain and can affect the performance of ED in that sometimes presence of signals is confused for their absence (noise) and vice versa. The traditional energy detection algorithm was based on fixed threshold and has been observed to be inefficient under noise uncertainty. The technique requires optimizing the threshold to be more flexible to check the noise uncertainty effects. The paper therefore proposed an algorithm relative to a unique environment which in effect considered the dynamism relatively and dependent on the environment. The results obtained demonstrated significant improvement compared to the traditional energy detection system
Audio compression has become one of the basic technologies of the multimedia age. The change in the telecommunication infrastructure, in recent years, from circuit switched to packet switched systems has also reflected on the way that speech and audio signals are carried in present systems. In many applications, such as the design of multimedia workstations and high quality audio transmission and storage, the goal is to achieve transparent coding of audio and speech signals at the lowest possible data rates. In other words, bandwidth cost money, therefore, the transmission and storage of information becomes costly. However, if we can use less data, both transmission and storage become cheaper. Further reduction in bit rate is an attractive proposition in applications like remote broadcast lines, studio links, satellite transmission of high quality audio and voice over internet.
PHOENIX AUDIO TECHNOLOGIES - A large Audio Signal Algorithm PortfolioHTCS LLC
Phoenix Audio Technology has the attached publication available which lists their Audio Signal Algorithm Portfolio, e.g. Multi Sensor Processing, Blind Source Separation, Echo and Reference Channel Canceling, Single Sensor Processing, Multi Resolution Analysis, Single Power Compression, Direction Finding, Data Tracking, Data Fusion, and more.
Performance Analysis of Cognitive Radio for Wi-Fi Signals Using Cyclostationa...IJERA Editor
The need for radio spectrum usage is increasing day by day with recent advancements in wireless system. But there is limited amount of spectrum available. So that for solving this problem Cognitive Radio (CR) is used for purpose of the spectrum utilization properly. Basically the Licensed users use the licensed bands but the unlicensed users should always check spectrum with the help of CR technology. The main aim of cognitive radio is to sense the spectrum continuously. In this paper, we have provided the proposal that how the capacity of the system can be increased by reuse the unused licensed band by simulating a Cognitive radio system. The secondary users can occupy free space (spectrum holes) and also licensed bands by continuously monitoring the spectrum. The requirements of cognitive radio systems will be investigated by considering spectrum sensing techniques. To achieve this, a Cyclostationary Spectrum Sensing technique is studied and applied to detect OFDM signals in a noisy environment. The results are obtained for the applications employed in high frequency, such as, Wi-Fi.
Architecture of direct_digital_synthesizanjunarayanan
A frequency synthesizer is an electronic device which generates a range of frequency mostly sine wave from a fixed clock provided. These frequency synthesizers are commonly found in radio receivers, mobile telephones radio telephones, wacky talkies, as local oscillators, satellite receivers, GPS system. Direct digital synthesizer is a frequency synthesizer which digitally creates arbitrary wave forms of different frequencies from the fixed frequency provided as clock input.DDS generates digital wave forms and these digital waveforms are converted to analog signals by the digital to analog converter connected at the output of DDS. The DDS designed here is a ROM based DDS. DDS has many advantages over PLL and other similar approaches such as fast settling time, sub-Hertz frequency resolution, continuous phase switching response and low phase noise. This system has many applications such as the confidential message transfer, speedy frequency switching.
Index terms –DDS-Direct Digital Synthesizer
Performance enhancement of dct based speaker recognition using wavelet de noi...eSAT Journals
Abstract Presence of noise in the speech signal is one of the major problems in Speaker Recognition. The speaker recognition performance gradually degrades as the intensity of noise increases. The system gives high accuracy when the speech signal is noise free, but in real life scenario getting a noise free speech signal is challenging. Hence, elimination of the noise from speech signal is an important aspect in speaker recognition process. This work uses wavelet based denoising of the recorded speech signal in order to enhance the performance of speaker recognition. In this paper, wavelet based denoising technique has been applied to the DCT based speaker recognition system which was proposed in our previous work. Additive white Gaussian noise has been added to the speech signal and performance analysis of the system has been done using different SNR value. Keywords: Wavelet denoising, AWGN, Speaker Recognition, Thresholding, DCT, Feature Extraction.
SIMULATIONS OF ADAPTIVE ALGORITHMS FOR SPATIAL BEAMFORMINGijiert bestjournal
The main aim of this paper is to simulate different types of Adaptive Algorithms for Spatial Beam forming,which is achieved by combinin g elements of a phased array in such a way that signals at particular angles experi ence constructive interference while others experience destructive interference. Here,s imulations are done on different types of Adaptive Algorithms in MATLAB and Simulink to de termine the desired signal from clutter/noise by updating its weight value for bett er execution speed and computational complexity and the characteristics of individual al gorithms are compared and their area of applications. Adaptive filter is a filter that s elf-adjusts its transfer function according to an optimization algorithm driven by an error sig nal. The adaptive beamforming algorithms are used to update the weight vectors pe riodically to track the signal source in time varying environment by adaptively modifying the system�s antenna pattern so that nulls are generated in the directions of the i nterference sources.
Implementation of Wide Band Frequency Synthesizer Base on DFS (Digital Frequ...IJMER
Wide Band Frequency Synthesizer has become essential components in wireless communication
systems. They are used as frequency synthesizers with precise and convenient digital control in both traditional
electronics, such as televisions and AM/FM radios, and modern consumer products among which cellular
mobile phone is a striking example.
IC fabrication technology advances have made monolithic integration possible. More and more
electronic devices can be put on the same chip to reduce the number of external components and then the costs.
Therefore, on a single chip we can accomplish many functions for which we might need to make several chips
work together a few years ago. A monolithic wide-band PLL is of great interests to wireless communication
applications due to both its low cost and convenience to switch between different communication standards.
The focus of this work is to implement a wide-band Frequency Synthesizer using as few as possible building
blocks and also as simple as possible structure.
A novel scheme to improve the spectrum sensing performanceIJCNCJournal
Due to limited availability of spectrum for license
d users only, the need for secondary access by unli
censed
users is increasing. Cognitive radio turns out to b
e helping this situation because all that is needed
is a
technique that could efficiently detect the empty s
paces and provide them to the secondary devices wit
hout
causing any interference to the primary (licensed)
users. Spectrum sensing is the foremost function of
the
cognitive radio which senses the environment for wh
ite spaces. Energy detection is one of the various
spectrum sensing techniques that are under research
. Earlier it was shown that energy detection works
better under AWGN channel as compared to Rayleigh c
hannel, however the conventional spectrum sensing
techniques have a high probability of false alarm a
nd also show a better probability of detection for
higher
values of SNR. There is a need for a new technique
that shows a reduced probability of false alarm as
well
as an increase in the probability of detection for
lower values of SNR. In the present work the conven
tional
energy detection technique has been enhanced to get
better results.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Performance evaluation of different spectrum sensing techniques for realistic...ijwmn
In this paper, the performance assessment of five different detection techniques from spectrum sensing
perspective in cognitive radio networks is proposed and implemented using the realistic implementation
oriented model (R-model) with signal processing operations. The performance assessment of the different
sensing techniques in the existence of unknown or imprecisely known impulsive noise levels is done by
considering the signal detection in cognitive radio networks under a non-parametric multisensory detection
scenario. The examination focuses on performance comparison of basic spectrum sensing mechanisms as,
energy detection (ED) and cyclostationary feature detection (CSFD) along with the eigenvalue-based
detection methods namely, Maximum-minimum eigenvalue detection (MMED), Roy’s largest Root Test
(RLRT) which requires knowledge of the noise variance and Generalized Likelihood Ratio Test (GLRT)
which can be implemented as a test of the largest eigenvalues vs. Maximum-likelihood estimates a noise
variance. From simulation results it is observed that the detection performance of the GLRT method is
better than the other techniques in realistic implementation oriented model.
Toward forward link interference cancellationShu Wang
A Presentation for CDG Technology Forum on Improving 3G Network Capacity, Coverage and Quality, April 20, 2006
Hyatt Regency San Francisco Airport, Burlingame, CA.
http://www.cdg.org/news/events/cdmaseminar/060420_NetworkCap/index.asp
Evaluation of Compressive Strength and Water Absorption of Styrene Butadiene...IJMER
In this research, effect of Styrene-Butadiene Rubber (SBR) latex on water absorption and
compressive strength of concrete has been studied. A locally available “RIPSTAR-148” is used as SBR
Latex.
It has been observed that SBR latex improves the internal structure of the latex modified
concrete resulting in considerable reduction in the water absorption value at 28 days of age. However,
at early age, the effect of SBR latex on water absorption is adverse. Same trend is noticed for the
compressive strength; at 7 days of age, SBR latex has negative effect while at 28 days, the addition of
SBR latex in concrete results in enhancement of compressive strength. Based on the results of this
study, latex modified concrete made using “RIPSTAR-148” may be recommended to be used in RC
structures in INDIA. However, for the mixes rich in cement, the dosage of “RIPSTAR-148” needs to be
adjusted to maintain required workability of concrete.
Effect of Air Entrainment on Compressive Strength, Density, and Ingredients o...IJMER
The micro air bubbles in concrete mix act as fine aggregates which lead to reduction of the
aggregates. The reduction of fine aggregates will cause reduction of water required for concrete mix
without impairing the strength of concrete mix. This reduction has to be considered in designing an air
entrained concrete mix. Theoretical (equations) and experimental study have been carried out to study the
effect of air entrainment on compressive strength, density and ingredients of fresh concrete mix. During
all the study, water cement ratio (w/c) was maintained constant at 0.5 to study the affection of air
entrainment (a %) on concrete mix. The results have shown substantial decreasing in cement, water,
aggregates and concrete density followed with decreasing in compressive strength of concrete. The results
of this study has given more promising to use it as a guide for concrete mix design to choose the most
appropriate concrete mix design economically.
PHOENIX AUDIO TECHNOLOGIES - A large Audio Signal Algorithm PortfolioHTCS LLC
Phoenix Audio Technology has the attached publication available which lists their Audio Signal Algorithm Portfolio, e.g. Multi Sensor Processing, Blind Source Separation, Echo and Reference Channel Canceling, Single Sensor Processing, Multi Resolution Analysis, Single Power Compression, Direction Finding, Data Tracking, Data Fusion, and more.
Performance Analysis of Cognitive Radio for Wi-Fi Signals Using Cyclostationa...IJERA Editor
The need for radio spectrum usage is increasing day by day with recent advancements in wireless system. But there is limited amount of spectrum available. So that for solving this problem Cognitive Radio (CR) is used for purpose of the spectrum utilization properly. Basically the Licensed users use the licensed bands but the unlicensed users should always check spectrum with the help of CR technology. The main aim of cognitive radio is to sense the spectrum continuously. In this paper, we have provided the proposal that how the capacity of the system can be increased by reuse the unused licensed band by simulating a Cognitive radio system. The secondary users can occupy free space (spectrum holes) and also licensed bands by continuously monitoring the spectrum. The requirements of cognitive radio systems will be investigated by considering spectrum sensing techniques. To achieve this, a Cyclostationary Spectrum Sensing technique is studied and applied to detect OFDM signals in a noisy environment. The results are obtained for the applications employed in high frequency, such as, Wi-Fi.
Architecture of direct_digital_synthesizanjunarayanan
A frequency synthesizer is an electronic device which generates a range of frequency mostly sine wave from a fixed clock provided. These frequency synthesizers are commonly found in radio receivers, mobile telephones radio telephones, wacky talkies, as local oscillators, satellite receivers, GPS system. Direct digital synthesizer is a frequency synthesizer which digitally creates arbitrary wave forms of different frequencies from the fixed frequency provided as clock input.DDS generates digital wave forms and these digital waveforms are converted to analog signals by the digital to analog converter connected at the output of DDS. The DDS designed here is a ROM based DDS. DDS has many advantages over PLL and other similar approaches such as fast settling time, sub-Hertz frequency resolution, continuous phase switching response and low phase noise. This system has many applications such as the confidential message transfer, speedy frequency switching.
Index terms –DDS-Direct Digital Synthesizer
Performance enhancement of dct based speaker recognition using wavelet de noi...eSAT Journals
Abstract Presence of noise in the speech signal is one of the major problems in Speaker Recognition. The speaker recognition performance gradually degrades as the intensity of noise increases. The system gives high accuracy when the speech signal is noise free, but in real life scenario getting a noise free speech signal is challenging. Hence, elimination of the noise from speech signal is an important aspect in speaker recognition process. This work uses wavelet based denoising of the recorded speech signal in order to enhance the performance of speaker recognition. In this paper, wavelet based denoising technique has been applied to the DCT based speaker recognition system which was proposed in our previous work. Additive white Gaussian noise has been added to the speech signal and performance analysis of the system has been done using different SNR value. Keywords: Wavelet denoising, AWGN, Speaker Recognition, Thresholding, DCT, Feature Extraction.
SIMULATIONS OF ADAPTIVE ALGORITHMS FOR SPATIAL BEAMFORMINGijiert bestjournal
The main aim of this paper is to simulate different types of Adaptive Algorithms for Spatial Beam forming,which is achieved by combinin g elements of a phased array in such a way that signals at particular angles experi ence constructive interference while others experience destructive interference. Here,s imulations are done on different types of Adaptive Algorithms in MATLAB and Simulink to de termine the desired signal from clutter/noise by updating its weight value for bett er execution speed and computational complexity and the characteristics of individual al gorithms are compared and their area of applications. Adaptive filter is a filter that s elf-adjusts its transfer function according to an optimization algorithm driven by an error sig nal. The adaptive beamforming algorithms are used to update the weight vectors pe riodically to track the signal source in time varying environment by adaptively modifying the system�s antenna pattern so that nulls are generated in the directions of the i nterference sources.
Implementation of Wide Band Frequency Synthesizer Base on DFS (Digital Frequ...IJMER
Wide Band Frequency Synthesizer has become essential components in wireless communication
systems. They are used as frequency synthesizers with precise and convenient digital control in both traditional
electronics, such as televisions and AM/FM radios, and modern consumer products among which cellular
mobile phone is a striking example.
IC fabrication technology advances have made monolithic integration possible. More and more
electronic devices can be put on the same chip to reduce the number of external components and then the costs.
Therefore, on a single chip we can accomplish many functions for which we might need to make several chips
work together a few years ago. A monolithic wide-band PLL is of great interests to wireless communication
applications due to both its low cost and convenience to switch between different communication standards.
The focus of this work is to implement a wide-band Frequency Synthesizer using as few as possible building
blocks and also as simple as possible structure.
A novel scheme to improve the spectrum sensing performanceIJCNCJournal
Due to limited availability of spectrum for license
d users only, the need for secondary access by unli
censed
users is increasing. Cognitive radio turns out to b
e helping this situation because all that is needed
is a
technique that could efficiently detect the empty s
paces and provide them to the secondary devices wit
hout
causing any interference to the primary (licensed)
users. Spectrum sensing is the foremost function of
the
cognitive radio which senses the environment for wh
ite spaces. Energy detection is one of the various
spectrum sensing techniques that are under research
. Earlier it was shown that energy detection works
better under AWGN channel as compared to Rayleigh c
hannel, however the conventional spectrum sensing
techniques have a high probability of false alarm a
nd also show a better probability of detection for
higher
values of SNR. There is a need for a new technique
that shows a reduced probability of false alarm as
well
as an increase in the probability of detection for
lower values of SNR. In the present work the conven
tional
energy detection technique has been enhanced to get
better results.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Performance evaluation of different spectrum sensing techniques for realistic...ijwmn
In this paper, the performance assessment of five different detection techniques from spectrum sensing
perspective in cognitive radio networks is proposed and implemented using the realistic implementation
oriented model (R-model) with signal processing operations. The performance assessment of the different
sensing techniques in the existence of unknown or imprecisely known impulsive noise levels is done by
considering the signal detection in cognitive radio networks under a non-parametric multisensory detection
scenario. The examination focuses on performance comparison of basic spectrum sensing mechanisms as,
energy detection (ED) and cyclostationary feature detection (CSFD) along with the eigenvalue-based
detection methods namely, Maximum-minimum eigenvalue detection (MMED), Roy’s largest Root Test
(RLRT) which requires knowledge of the noise variance and Generalized Likelihood Ratio Test (GLRT)
which can be implemented as a test of the largest eigenvalues vs. Maximum-likelihood estimates a noise
variance. From simulation results it is observed that the detection performance of the GLRT method is
better than the other techniques in realistic implementation oriented model.
Toward forward link interference cancellationShu Wang
A Presentation for CDG Technology Forum on Improving 3G Network Capacity, Coverage and Quality, April 20, 2006
Hyatt Regency San Francisco Airport, Burlingame, CA.
http://www.cdg.org/news/events/cdmaseminar/060420_NetworkCap/index.asp
Evaluation of Compressive Strength and Water Absorption of Styrene Butadiene...IJMER
In this research, effect of Styrene-Butadiene Rubber (SBR) latex on water absorption and
compressive strength of concrete has been studied. A locally available “RIPSTAR-148” is used as SBR
Latex.
It has been observed that SBR latex improves the internal structure of the latex modified
concrete resulting in considerable reduction in the water absorption value at 28 days of age. However,
at early age, the effect of SBR latex on water absorption is adverse. Same trend is noticed for the
compressive strength; at 7 days of age, SBR latex has negative effect while at 28 days, the addition of
SBR latex in concrete results in enhancement of compressive strength. Based on the results of this
study, latex modified concrete made using “RIPSTAR-148” may be recommended to be used in RC
structures in INDIA. However, for the mixes rich in cement, the dosage of “RIPSTAR-148” needs to be
adjusted to maintain required workability of concrete.
Effect of Air Entrainment on Compressive Strength, Density, and Ingredients o...IJMER
The micro air bubbles in concrete mix act as fine aggregates which lead to reduction of the
aggregates. The reduction of fine aggregates will cause reduction of water required for concrete mix
without impairing the strength of concrete mix. This reduction has to be considered in designing an air
entrained concrete mix. Theoretical (equations) and experimental study have been carried out to study the
effect of air entrainment on compressive strength, density and ingredients of fresh concrete mix. During
all the study, water cement ratio (w/c) was maintained constant at 0.5 to study the affection of air
entrainment (a %) on concrete mix. The results have shown substantial decreasing in cement, water,
aggregates and concrete density followed with decreasing in compressive strength of concrete. The results
of this study has given more promising to use it as a guide for concrete mix design to choose the most
appropriate concrete mix design economically.
An Effective Tea Leaf Recognition Algorithm for Plant Classification Using Ra...IJMER
A leaf is an organ of a vascular plant, as identified in botanical terms, and in particular in plant morphology. Naturally a leaf is a thin, flattened organ bear above ground and it is mainly used for photosynthesis. Recognition of plants has become an active area of research as most of the plant species are at the risk of extinction. Most of the leaves cannot be recognized easily since some are not flat (e.g. succulent leaves and conifers), some does not grow above ground (e.g. bulb scales), and some does not undergo photosynthetic function (e.g. cataphylls, spines, and cotyledons).In this paper, we mainly focused on tea leaves to identify the leaf type for improving tea leaf classification. Tea leaf images are loaded from digital cameras or scanners in the system. This proposed approach consists of three phases such as preprocessing, feature extraction and classification to process the loaded image. The tea leaf images can be identified accurately in the preprocessing phase by fuzzy denoising using Dual Tree Discrete Wavelet Transform (DT-DWT) in order to remove the noisy features and boundary enhancement to obtain the shape of leaf accurately. In the feature extraction phase, Digital Morphological Features (DMFs) are derived to improve the classification accuracy. Radial Basis Function (RBF) is used for efficient classification. The RBF is trained by 60 tea leaves to classify them into 6 types. Experimental results proved that the proposed method classifies the tea leaves with more accuracy in less time. Thus, the proposed method achieves more accuracy in retrieving the leaf type.
T04201162168Optimal Allocation of FACTS Device with Multiple Objectives Using...IJMER
In this paper Multi objective functions are simultaneously considered as the indexes of the system performance minimize total generation fuel cost and maximize system load-ability within system security margin. To find the optimal location and optimal value for Thyristor Controlled Series Compensator (TCSC) using optimization technique Genetic Algorithm (GA) to maximize system load-ability and minimize the system losses considering multi objectives optimization approach. A GA based Optimal Power Flow (OPF) is proposed to determine the type of FACTS (Flexible AC Transmission system) controllers, its optimal location and rating of the devices in power systems. The value of TCSC and line losses is applied as measure of power system performance. The type of FACTS controllers are used and modeled for steady-state studies: TCSC, minimize total generation fuel cost and maximize system load-ability within system security margin. Simulations will be carrying on IEEE30 bus power system for type of FACTS devices.
Effect of Preform Geometry on the Material Behaviour and the Densification Me...IJMER
The present investigation pertains to generate experimental data in order to establish the
influence of initial preform geometries on the material behaviour and the operative densification
mechanism/s during hot upsetforging of sintered AISI 9840 P/M Steel composition prepared from the
elemental powders. Powder blend corresponding to AISI 9840= C(0.4%), Mn(0.8%), Si(0.3%),
Ni(1.0%),Cr(0.8%), Mo(0.25%) and Fe(96.4%) composition was prepared on a pot mill and the
blending was carried out for a period' of 16hrs. while maintaining the powder to ball ratio 1.1: I by
weight. Compacts of 27.5mm diameter and 12 - 24mm heights were prepared from the aforesaid
blend in the density range of 84±1 percent of theoretical density by applying accurately controlled
pressures in the range of 460±10 MPa and by taking pre-weighed powders. Indigenously developed
ceramic coating was applied all over the compact surfaces and dried under an ambient conditions
for a period of 10- 12 hrs. These ceramic coated compacts were recoated 90° to the previous coating
and re- dried under the aforesaid conditions. These ceramic coated preforms were sintered in an
electric muffle furnace for a period of 90 minutes at 11500±10°C. Immediately after the completion
of the sintering schedule, the preforms corresponding to 0.45, 0.68 and 0.92 initial aspect ratios were
axially hot forged to different height strains. Analysis of the experimental data has revealed that the
lower aspect ratio preforms densified rapidly compared to higher aspect ratios and the densification
curves corresponded to a third order polynomial of the form:(ρf/ρth) = ao +al €h + a2€h2 +a3€h3;
where, €h= ln (Ho/Hf) and a0, al, a2 anda3 are empirically determined constants. Further analysis
has established that the Poisson's ratio would always remain less than one half and will have the
tendency to approach to a limiting value of 0.5 in the near vicinity of the theoretical density.
Influence of the preform geometry is established to be quite pronounced and has affected the
densification curves and Poisson's ratio with density
A Survey of User Authentication Schemes for Mobile DeviceIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
A ZVS Interleaved Boost AC/DC Converter Using Super Capacitor Power for Hybri...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Estimation of Manufacturing Costs in the Early Stages of Product Development ...IJMER
ABSTRACT : One of the crucial factors in increase of productivity of supply chains is the management of production
costs. Since the number of methods and tools used to estimate the production costs in product development phase is limited,
the designers often estimate the costs based on their experience. The designers can mainly affect the direct costs of a
product, including material, labor and purchased parts. Direct costs vary greatly depending on the number of produced
units. Indirect costs include for example the work in process, storage and internal transportations. The developed software
prototype is based on the Lucas method. It will take a simple and ideal part, whose costs are known and then use factors to
produce the final costs. The application calculates sophisticated estimates about how much it would cost to produce a single
part. The developed software seems to work surprisingly well. It may not tell the final truth about the component costs but
can be used to open the eyes of the designer when the costs of the component under design are growing too high. It can also
be used to find the most suitable manufacturing method and when considering the make or buy decisions.
Keywords: Cost estimation, Manufacturing costs, Product Development
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Teager Energy Operation on Wavelet Packet Coefficients for Enhancing Noisy Sp...CSCJournals
In this paper a new thresholding based speech enhancement approach is presented, where the threshold is statistically determined by employing the Teager energy operation on the Wavelet Packet (WP) coefficients of noisy speech. The threshold thus obtained is applied on the WP coefficients of the noisy speech by using a hard thresholding function in order to obtain an enhanced speech. Detailed simulations are carried out in the presence of white, car, pink, and babble noises to evaluate the performance of the proposed method. Standard objective measures, spectrogram representations and subjective listening tests show that the proposed method outperforms the existing state-of-the-art thresholding based speech enhancement approaches for noisy speech from high to low levels of SNR.
EFFECT OF DYNAMIC TIME WARPING ON ALIGNMENT OF PHRASES AND PHONEMESkevig
Speech synthesis and recognition are the basic techniques used for man-machine communication. This type
of communication is valuable when our hands and eyes are busy in some other task such as driving a
vehicle, performing surgery, or firing weapons at the enemy. Dynamic time warping (DTW) is mostly used
for aligning two given multidimensional sequences. It finds an optimal match between the given sequences.
The distance between the aligned sequences should be relatively lesser as compared to unaligned
sequences. The improvement in the alignment may be estimated from the corresponding distances. This
technique has applications in speech recognition, speech synthesis, and speaker transformation. The
objective of this research is to investigate the amount of improvement in the alignment corresponding to the
sentence based and phoneme based manually aligned phrases. The speech signals in the form of twenty five
phrases were recorded from each of six speakers (3 males and 3 females). The recorded material was
segmented manually and aligned at sentence and phoneme level. The aligned sentences of different speaker
pairs were analyzed using HNM and the HNM parameters were further aligned at frame level using DTW.
Mahalanobis distances were computed for each pair of sentences. The investigations have shown more than
20 % reduction in the average Mahalanobis distances.
Effect of Dynamic Time Warping on Alignment of Phrases and Phonemeskevig
Speech synthesis and recognition are the basic techniques used for man-machine communication. This type
of communication is valuable when our hands and eyes are busy in some other task such as driving a
vehicle, performing surgery, or firing weapons at the enemy. Dynamic time warping (DTW) is mostly used
for aligning two given multidimensional sequences. It finds an optimal match between the given sequences.
The distance between the aligned sequences should be relatively lesser as compared to unaligned
sequences. The improvement in the alignment may be estimated from the corresponding distances. This
technique has applications in speech recognition, speech synthesis, and speaker transformation. The
objective of this research is to investigate the amount of improvement in the alignment corresponding to the
sentence based and phoneme based manually aligned phrases. The speech signals in the form of twenty five
phrases were recorded from each of six speakers (3 males and 3 females). The recorded material was
segmented manually and aligned at sentence and phoneme level. The aligned sentences of different speaker
pairs were analyzed using HNM and the HNM parameters were further aligned at frame level using DTW.
Mahalanobis distances were computed for each pair of sentences. The investigations have shown more than
20 % reduction in the average Mahalanobis distances.
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Effect of Singular Value Decomposition Based Processing on Speech Perceptionkevig
Speech is an important biological signal for primary mode of communication among human being and also the most natural and efficient form of exchanging information among human in speech. Speech processing is the most important aspect in signal processing. In this paper the theory of linear algebra called singular value decomposition (SVD) is applied to the speech signal. SVD is a technique for deriving important parameters of a signal. The parameters derived using SVD may further be reduced by perceptual evaluation of the synthesized speech using only perceptually important parameters, where the speech signal can be compressed so that the information can be transformed into compressed form without losing its quality. This technique finds wide applications in speech compression, speech recognition, and speech synthesis. The objective of this paper is to investigate the effect of SVD based feature selection of the input speech on the perception of the processed speech signal. The speech signal which is in the form of vowels \a\, \e\, \u\ were recorded from each of the six speakers (3 males and 3 females). The vowels for the six speakers were analyzed using SVD based processing and the effect of the reduction in singular values was investigated on the perception of the resynthesized vowels using reduced singular values. Investigations have shown that the number of singular values can be drastically reduced without significantly affecting the perception of the vowels.
Effect of Singular Value Decomposition Based Processing on Speech Perceptionkevig
Speech is an important biological signal for primary mode of communication among human being and also
the most natural and efficient form of exchanging information among human in speech. Speech processing
is the most important aspect in signal processing. In this paper the theory of linear algebra called singular
value decomposition (SVD) is applied to the speech signal. SVD is a technique for deriving important
parameters of a signal. The parameters derived using SVD may further be reduced by perceptual
evaluation of the synthesized speech using only perceptually important parameters, where the speech signal
can be compressed so that the information can be transformed into compressed form without losing its
quality. This technique finds wide applications in speech compression, speech recognition, and speech
synthesis. The objective of this paper is to investigate the effect of SVD based feature selection of the input
speech on the perception of the processed speech signal. The speech signal which is in the form of vowels
\a\, \e\, \u\ were recorded from each of the six speakers (3 males and 3 females). The vowels for the six
speakers were analyzed using SVD based processing and the effect of the reduction in singular values was
investigated on the perception of the resynthesized vowels using reduced singular values. Investigations
have shown that the number of singular values can be drastically reduced without significantly affecting the
perception of the vowels.
Automatic recognition of speech using computers is a challenging issue. This paper describes a technique that uses Auto associative Neural Network (AANN) to recognized speech based on features using Sonogram. Modeling techniques such as AANN were used to model each individual word which is trained to the system. Each isolated word Segment using Voice Activity Detection (VAD) from the test sentence is matched against these models for finding the semantic representation of the test input speech. Experimental results of AANN shows good performance in recognized rate.
A Study on Translucent Concrete Product and Its Properties by Using Optical F...IJMER
- Translucent concrete is a concrete based material with light-transferring properties,
obtained due to embedded light optical elements like Optical fibers used in concrete. Light is conducted
through the concrete from one end to the other. This results into a certain light pattern on the other
surface, depending on the fiber structure. Optical fibers transmit light so effectively that there is
virtually no loss of light conducted through the fibers. This paper deals with the modeling of such
translucent or transparent concrete blocks and panel and their usage and also the advantages it brings
in the field. The main purpose is to use sunlight as a light source to reduce the power consumption of
illumination and to use the optical fiber to sense the stress of structures and also use this concrete as an
architectural purpose of the building
Developing Cost Effective Automation for Cotton Seed DelintingIJMER
A low cost automation system for removal of lint from cottonseed is to be designed and
developed. The setup consists of stainless steel drum with stirrer in which cottonseeds having lint is mixed
with concentrated sulphuric acid. So lint will get burn. This lint free cottonseed treated with lime water to
neutralize acidic nature. After water washing this cottonseeds are used for agriculter purpose
Study & Testing Of Bio-Composite Material Based On Munja FibreIJMER
The incorporation of natural fibres such as munja fiber composites has gained
increasing applications both in many areas of Engineering and Technology. The aim of this study is to
evaluate mechanical properties such as flexural and tensile properties of reinforced epoxy composites.
This is mainly due to their applicable benefits as they are light weight and offer low cost compared to
synthetic fibre composites. Munja fibres recently have been a substitute material in many weight-critical
applications in areas such as aerospace, automotive and other high demanding industrial sectors. In
this study, natural munja fibre composites and munja/fibreglass hybrid composites were fabricated by a
combination of hand lay-up and cold-press methods. A new variety in munja fibre is the present work
the main aim of the work is to extract the neat fibre and is characterized for its flexural characteristics.
The composites are fabricated by reinforcing untreated and treated fibre and are tested for their
mechanical, properties strictly as per ASTM procedures.
Hybrid Engine (Stirling Engine + IC Engine + Electric Motor)IJMER
Hybrid engine is a combination of Stirling engine, IC engine and Electric motor. All these 3 are
connected together to a single shaft. The power source of the Stirling engine will be a Solar Panel. The aim of
this is to run the automobile using a Hybrid engine
Fabrication & Characterization of Bio Composite Materials Based On Sunnhemp F...IJMER
The present day technology demands eco-friendly developments. In this era the
composite material are playing a vital roal in different field of Engineering .The composite materials
are using as a principle materials. Nowaday the composite materials are utilizing as a important
component of engineering field .Where as the importance of the applications of composites is well
known, but thrust on the use of natural fibres in it for reinforcement has been given priority for some
times. But changing from synthetic fibres to natural fibres provides only half green-composites. A
partial green composite will be achieved if the matrix component is also eco-friendly. Keeping this in
view, a detailed literature surveyed has been carried out through various issues of the Journals
related to this field. The material systems used are sunnhemp fibres. Some epoxy and hardener has
been also added for stability and drying of the bio-composites. Various graphs and bar-charts are
super-imposed on each other for comparison among themselves and Graphs is plotted on MAT LAB
and ORIGIN 6.0 software. To determining tensile strengths, Various properties for different biocomposites
have been compared among themselves. Comparison of the behaviour of bio-composites of
this work has been also compare with other works. The bio-composites developed in this work are
likely to get applications in fall ceilings, partitions, bio-degradable packagings, automotive interiors,
sports things (e.g. rackets, nets, etc.), toys etc.
Geochemistry and Genesis of Kammatturu Iron Ores of Devagiri Formation, Sandu...IJMER
The Greenstone belts of Karnataka are enriched in BIFs in Dharwar craton, where Iron
formations are confined to the basin shelf, clearly separated from the deeper-water iron formation that
accumulated at the basin margin and flanking the marine basin. Geochemical data procured in terms of
major, trace and REE are plotted in various diagrams to interpret the genesis of BIFs. Al2O3, Fe2O3 (T),
TiO2, CaO, and SiO2 abundances and ratios show a wide variation. Ni, Co, Zr, Sc, V, Rb, Sr, U, Th,
ΣREE, La, Ce and Eu anomalies and their binary relationships indicate that wherever the terrigenous
component has increased, the concentration of elements of felsic such as Zr and Hf has gone up. Elevated
concentrations of Ni, Co and Sc are contributed by chlorite and other components characteristic of basic
volcanic debris. The data suggest that these formations were generated by chemical and clastic
sedimentary processes on a shallow shelf. During transgression, chemical precipitation took place at the
sediment-water interface, whereas at the time of regression. Iron ore formed with sedimentary structures
and textures in Kammatturu area, in a setting where the water column was oxygenated.
Experimental Investigation on Characteristic Study of the Carbon Steel C45 in...IJMER
In this paper, the mechanical characteristics of C45 medium carbon steel are investigated
under various working conditions. The main characteristic to be studied on this paper is impact toughness
of the material with different configurations and the experiment were carried out on charpy impact testing
equipment. This study reveals the ability of the material to absorb energy up to failure for various
specimen configurations under different heat treated conditions and the corresponding results were
compared with the analysis outcome
Non linear analysis of Robot Gun Support Structure using Equivalent Dynamic A...IJMER
Robot guns are being increasingly employed in automotive manufacturing to replace
risky jobs and also to increase productivity. Using a single robot for a single operation proves to be
expensive. Hence for cost optimization, multiple guns are mounted on a single robot and multiple
operations are performed. Robot Gun structure is an efficient way in which multiple welds can be done
simultaneously. However mounting several weld guns on a single structure induces a variety of
dynamic loads, especially during movement of the robot arm as it maneuvers to reach the weld
locations. The primary idea employed in this paper, is to model those dynamic loads as equivalent G
force loads in FEA. This approach will be on the conservative side, and will be saving time and
subsequently cost efficient. The approach of the paper is towards creating a standard operating
procedure when it comes to analysis of such structures, with emphasis on deploying various technical
aspects of FEA such as Non Linear Geometry, Multipoint Constraint Contact Algorithm, Multizone
meshing .
Static Analysis of Go-Kart Chassis by Analytical and Solid Works SimulationIJMER
This paper aims to do modelling, simulation and performing the static analysis of a go
kart chassis consisting of Circular beams. Modelling, simulations and analysis are performed using 3-D
modelling software i.e. Solid Works and ANSYS according to the rulebook provided by Indian Society of
New Era Engineers (ISNEE) for National Go Kart Championship (NGKC-14).The maximum deflection is
determined by performing static analysis. Computed results are then compared to analytical calculation,
where it is found that the location of maximum deflection agrees well with theoretical approximation but
varies on magnitude aspect.
In récent year various vehicle introduced in market but due to limitation in
carbon émission and BS Séries limitd speed availability vehicle in the market and causing of
environnent pollution over few year There is need to decrease dependancy on fuel vehicle.
bicycle is to be modified for optional in the future To implement new technique using change in
pedal assembly and variable speed gearbox such as planetary gear optimise speed of vehicle
with variable speed ratio.To increase the efficiency of bicycle for confortable drive and to
reduce torque appli éd on bicycle. we introduced epicyclic gear box in which transmission done
throgh Chain Drive (i.e. Sprocket )to rear wheel with help of Epicyclical gear Box to give
number of différent Speed during driving.To reduce torque requirent in the cycle with change in
the pedal mechanism
Integration of Struts & Spring & Hibernate for Enterprise ApplicationsIJMER
The proposal of this paper is to present Spring Framework which is widely used in
developing enterprise applications. Considering the current state where applications are developed using
the EJB model, Spring Framework assert that ordinary java beans(POJO) can be utilize with minimal
modifications. This modular framework can be used to develop the application faster and can reduce
complexity. This paper will highlight the design overview of Spring Framework along with its features that
have made the framework useful. The integration of multiple frameworks for an E-commerce system has
also been addressed in this paper. This paper also proposes structure for a website based on integration of
Spring, Hibernate and Struts Framework.
Microcontroller Based Automatic Sprinkler Irrigation SystemIJMER
Microcontroller based Automatic Sprinkler System is a new concept of using
intelligence power of embedded technology in the sprinkler irrigation work. Designed system replaces
the conventional manual work involved in sprinkler irrigation to automatic process. Using this system a
farmer is protected against adverse inhuman weather conditions, tedious work of changing over of
sprinkler water pipe lines & risk of accident due to high pressure in the water pipe line. Overall
sprinkler irrigation work is transformed in to a comfortableautomatic work. This system provides
flexibility & accuracy in respect of time set for the operation of a sprinkler water pipe lines. In present
work the author has designed and developed an automatic sprinkler irrigation system which is
controlled and monitored by a microcontroller interfaced with solenoid valves.
On some locally closed sets and spaces in Ideal Topological SpacesIJMER
In this paper we introduce and characterize some new generalized locally closed sets
known as
δ
ˆ
s-locally closed sets and spaces are known as
δ
ˆ
s-normal space and
δ
ˆ
s-connected space and
discussed some of their properties
Intrusion Detection and Forensics based on decision tree and Association rule...IJMER
This paper present an approach based on the combination of, two techniques using
decision tree and Association rule mining for Probe attack detection. This approach proves to be
better than the traditional approach of generating rules for fuzzy expert system by clustering methods.
Association rule mining for selecting the best attributes together and decision tree for identifying the
best parameters together to create the rules for fuzzy expert system. After that rules for fuzzy expert
system are generated using association rule mining and decision trees. Decision trees is generated for
dataset and to find the basic parameters for creating the membership functions of fuzzy inference
system. Membership functions are generated for the probe attack. Based on these rules we have
created the fuzzy inference system that is used as an input to neuro-fuzzy system. Fuzzy inference
system is loaded to neuro-fuzzy toolbox as an input and the final ANFIS structure is generated for
outcome of neuro-fuzzy approach. The experiments and evaluations of the proposed method were
done with NSL-KDD intrusion detection dataset. As the experimental results, the proposed approach
based on the combination of, two techniques using decision tree and Association rule mining
efficiently detected probe attacks. Experimental results shows better results for detecting intrusions as
compared to others existing methods
Natural Language Ambiguity and its Effect on Machine LearningIJMER
"Natural language processing" here refers to the use and ability of systems to process
sentences in a natural language such as English, rather than in a specialized artificial computer
language such as C++. The systems of real interest here are digital computers of the type we think of as
personal computers and mainframes. Of course humans can process natural languages, but for us the
question is whether digital computers can or ever will process natural languages. We have tried to
explore in depth and break down the types of ambiguities persistent throughout the natural languages
and provide an answer to the question “How it affects the machine translation process and thereby
machine learning as whole?” .
Today in era of software industry there is no perfect software framework available for
analysis and software development. Currently there are enormous number of software development
process exists which can be implemented to stabilize the process of developing a software system. But no
perfect system is recognized till yet which can help software developers for opting of best software
development process. This paper present the framework of skillful system combined with Likert scale. With
the help of Likert scale we define a rule based model and delegate some mass score to every process and
develop one tool name as MuxSet which will help the software developers to select an appropriate
development process that may enhance the probability of system success.
Material Parameter and Effect of Thermal Load on Functionally Graded CylindersIJMER
The present study investigates the creep in a thick-walled composite cylinders made
up of aluminum/aluminum alloy matrix and reinforced with silicon carbide particles. The distribution
of SiCp is assumed to be either uniform or decreasing linearly from the inner to the outer radius of
the cylinder. The creep behavior of the cylinder has been described by threshold stress based creep
law with a stress exponent of 5. The composite cylinders are subjected to internal pressure which is
applied gradually and steady state condition of stress is assumed. The creep parameters required to
be used in creep law, are extracted by conducting regression analysis on the available experimental
results. The mathematical models have been developed to describe steady state creep in the composite
cylinder by using von-Mises criterion. Regression analysis is used to obtain the creep parameters
required in the study. The basic equilibrium equation of the cylinder and other constitutive equations
have been solved to obtain creep stresses in the cylinder. The effect of varying particle size, particle
content and temperature on the stresses in the composite cylinder has been analyzed. The study
revealed that the stress distributions in the cylinder do not vary significantly for various combinations
of particle size, particle content and operating temperature except for slight variation observed for
varying particle content. Functionally Graded Materials (FGMs) emerged and led to the development
of superior heat resistant materials.
Energy Audit is the systematic process for finding out the energy conservation
opportunities in industrial processes. The project carried out studies on various energy conservation
measures application in areas like lighting, motors, compressors, transformer, ventilation system etc.
In this investigation, studied the technical aspects of the various measures along with its cost benefit
analysis.
Investigation found that major areas of energy conservation are-
1. Energy efficient lighting schemes.
2. Use of electronic ballast instead of copper ballast.
3. Use of wind ventilators for ventilation.
4. Use of VFD for compressor.
5. Transparent roofing sheets to reduce energy consumption.
So Energy Audit is the only perfect & analyzed way of meeting the Industrial Energy Conservation.
An Implementation of I2C Slave Interface using Verilog HDLIJMER
The focus of this paper is on implementation of Inter Integrated Circuit (I2C) protocol
following slave module for no data loss. In this paper, the principle and the operation of I2C bus protocol
will be introduced. It follows the I2C specification to provide device addressing, read/write operation and
an acknowledgement. The programmable nature of device provide users with the flexibility of configuring
the I2C slave device to any legal slave address to avoid the slave address collision on an I2C bus with
multiple slave devices. This paper demonstrates how I2C Master controller transmits and receives data to
and from the Slave with proper synchronization.
The module is designed in Verilog and simulated in ModelSim. The design is also synthesized in Xilinx
XST 14.1. This module acts as a slave for the microprocessor which can be customized for no data loss.
Discrete Model of Two Predators competing for One PreyIJMER
This paper investigates the dynamical behavior of a discrete model of one prey two
predator systems. The equilibrium points and their stability are analyzed. Time series plots are obtained
for different sets of parameter values. Also bifurcation diagrams are plotted to show dynamical behavior
of the system in selected range of growth parameter
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Knowledge engineering: from people to machines and back
Development of Algorithm for Voice Operated Switch for Digital Audio Control Systems
1. International Journal of Modern Engineering Research (IJMER)
www.ijmer.com
Vol. 3, Issue. 5, Sep - Oct. 2013 pp-2646-2655
ISSN: 2249-6645
Development of Algorithm for Voice Operated Switch for
Digital Audio Control Systems
Gokula Krishnan1, Ram Singh2, Satyanarayana3
1
(M.Tech, DSCE, ECE Department, SNIST, Hyderabad, INDIA)
2
(Scientist ‘E’, RCMA, DRDO, Hyderabad, INDIA)
3
(Assistant professor, ECE Department, SNIST, Hyderabad, INDIA)
ABSTRACT: VOS (voice Operated Switch) is a switch that operates when sound over a certain threshold is detected. It is
usually used to turn on a transmitter or recorder when someone speaks and turn it off when they stop speaking. It is used
instead of a push-to-talk button on transmitters or to save storage space on recording devices. Unlike push-to-talk (PTT)
operation, VOS is automatic. The user can keep his hands free while talking. But VOS also has some significant
disadvantages that explain why PTT is still common. The Present VOS technology works based on the comparison of the
energy estimate in speech band and the noise band. The bandwidth of speech band is from 300Hz to 3.3 KHz and for noise
band it is from 3.3 KHz to 6.6 KHz. The major disadvantage with this technique is false operation of VOS due to noise
interference or heavy breathing or a side conversation. Hence, a DSP based algorithm is proposed to be developed for
DACS (Digital Audio Control System) to improve the performance and the noise suppression.
Keywords: Envelope dynamics, Noise estimation, Speech pause detection, SNR (Signal to Noise ratio), VAD (Voice activity
detection).
I. INTRODUCTION
Now a day‟s speech recognition is becoming more and more popular technology in the society. The innovative
technologies in mobile telecommunication, robust speech recognition and digital hearing aids are a strongly dynamic force in
the development of real-time noise reduction algorithms. The number of publications on single-microphone noise reduction
algorithms indicates an unbroken interest in this research field over the past two or three decades. A decisive point for these
kind of algorithms is the synchronized estimate of the object speech spectrum and the interfering noise spectrum in
particular. Cockpit voice recorder in aircraft records many cockpit voices, such as speaker voices, noises and background
sounds. In these communications, the speech signal which is transmitted is corrupted by additive acoustical noises. These
noises may be from non-stationary source and hence there may be situations where only noise segment or non-speech
segment is present, hence it is necessary to update the noise spectrum estimate as often as possible to sustain an effective
noise reduction. This can be done, whenever target speech is absent, which means that the input signal consists of only noise.
Computational and memory requirements should be as low as possible since these algorithms may be ported on a digital
circuit.
Speech detection is a process where speech segments be reliably separated from non-speech and activates VOS
when only speech segments are detected. The required characteristics of an ideal endpoint detector are: reliability,
robustness, accuracy, adaptation, implicitly, real-time processing and know a priori knowledge of the noise.
Earlier, the VOS technology works based on the comparison of the energy estimate in speech band and the noise
band. We calculate the signal to noise ratio for both the bands i.e. speech band and noise band and based on a threshold the
operation of VOS will take place. The major disadvantage with this technique is false operation of VOS due to noise
interference or heavy breathing or a side conversation or any other background noise such as helicopter noise or babble noise
etc. The techniques used in this algorithm are discussed in the later sections.
Hence VAD (Voice activity detector) algorithms are developed and employed to make voice operated switch work
efficiently and this also increases the switching speed of the voice operated switch.
VAD techniques are designed using various methods. Most of them use heuristically chose statistical properties of
speech parameters like: energy, pitch, entropy etc. Therefore, the performances of different VAD are different and varying
according to the level and type of signal-to-noise ratio (SNR). As a result, the performances of different speech based
systems are significantly sensitive to the employed VAD technique. Therefore, VAD algorithm should be carefully chosen
while designing a speech based system.
Several VAD algorithms have been standardized for specific applications. The most commonly mentioned includes
ITU-T Recommendation G.729 Annex B [1] and ETSI AMR Option 2 VAD [2], which aim to design simple features that
can be implemented in embedded applications efficiently, such as audio recording and transmission on mobile phones. In
these systems, speech are often recorded with close-talk microphones, which ensures the sound level of speech is always
much higher than background noise. Back then, VAD algorithms often dealt with only little or no noise corruption in speech
coding applications and with separate recording utterances in speech recognition systems. Up to recently, advances in
various speech applications require the detection of human speech in a continuous real-time fashion, and is often corrupted
by a wide variety classes of noise. Algorithms for VAD had grown accordingly over the years. Most of the speech activity
detectors are based on either time domain or frequency domain approach. Sangwan, Chiranth [3] have compared various
VAD algorithms. The core of any VAD proposed consists of two parts: a „feature extraction‟ and a „speech/ non-speech
decision mechanism.
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It is necessary to update the noise spectrum estimate as often as possible to sustain an effective noise reduction.
Different algorithms have been proposed which continuously update the noise estimate and hence avoid the need for explicit
speech pause detection. Martin [4] uses the minimum of the sub-band signal power within a time window of about 1S as an
estimate of the noise power in the respective sub-band. Paul proposed a continuous noise estimation scheme similar to
Martin‟s which is computationally more efficient. This scheme was, however, not systematically tested.
Hirsch and Ehrlicher proposed an algorithm [5] which is based on the observation that the most commonly
occurring spectral magnitude value in clean speech. Hence, having noisy speech their algorithm measures the distribution
density function of the spectral magnitude and density determines the maxima which are then used as an estimate of the
respective noise magnitude. These kind of algorithms which avoid speech pause detection for noise estimation are supposed
to cope better with non-stationary (i.e., fluctuating) noise, since they are generally faster in their adaptation to changing noise
levels even during speech activity. On the other hand, the continuous update of the noise estimate (Independently in the subbands) is susceptible to erroneously capture speech energy. This, however, leads inevitably to speech deterioration in a
subsequent noise reduction process. Fischer and Stahl proposed a spectral subtraction noise reduction algorithm with a
continuous noise spectrum up- dating scheme. They found that the corruption of the noise estimate by speech is too large to
be further considered and conclude that voice activity detection plays an important role and cannot be fully omitted,
Recently Nemer et al. proposed to use the kurtosis (fourth-order statistics) of the noisy signal to continuously estimate
speech and noise energies. The examples presented used noisy speech signals with positive signal-to-noise ratios (SNRs) and
yield promising results, but further research is required to extend these results to negative SNR s and different classes of
noise, respectively. Dendrinos and Bakamidis [6] presented an algorithm for determining the starting and ending points of
speech segments in colored-noise environments through singular value decomposition based on some thresholds which have
been determined experimentally. Good performance was proved for SNRs higher than 0 db. However, the complexity of the
algorithm makes a real-time implementation difficult.
Weiwu Jiang, Wai Kit Lo [7] presented a novel VAD algorithm using MVSS (Maximum Values of Sub-band SNR)
as a decision feature. Here the given the spectrum of a speech utterance transformed by DFT, it first divides the whole
spectrum into several sub-bands. Secondly, sub-band SNRs are estimated and maximum values of sub-band SNR (MVSS)
are extracted as detection features. The background noise estimation and final VAD decision are made by comparing feature
value with an estimated threshold. During initialization, the estimated noise spectrum and threshold are calculated by
assuming that speech always follows an initial period of noise.
As the basic requirement to develop or modify an algorithm is to identify the noise i.e. the noisy speech sample is
processed by voice operated switch to allow the presence of audio in case of speech and mute when only noise is present.
Based on the above algorithms a modified algorithm is presented and compared with the conventional energy based
algorithm.
This paper is organized as it starts with a review of the conventional energy based algorithm and proposed
algorithm. Next section reports the expected results of the algorithms under various background noise conditions. Finally,
conclusions are presented.
II. ALGORITHMS
The algorithms that were implemented for voice operated switch are discussed in this chapter. In all the mentioned
algorithms the plain speech is mixed with various noises like white noise, pink noise, brown noise, helicopter noise etc. with
0db, 3db, 5db, 10db, 15db SNR levels (Signal to Noise Ratio). It will be called as noisy speech from now, which are used in
the experiments.
2.1 Conventional energy based algorithm
This algorithm works based on the comparison of the energy estimate of the noisy speech. In general the bandwidth
of the speech band is from 300Hz to 3.3 KHz and for noise band it is from 3.3 KHz to 6.6 KHz. Therefore using the filters
the noisy speech is divided into two bands, that is the speech band and the noise band by assuming the cut off frequency of
3000 Hz. The Butterworth filter was preferred over other filters based on the parameters suitable to the algorithm.
Fig1: Conventional energy based algorithm block diagram
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The energies of both the speech band and noise band are calculated by considering a window or frame length of 160
samples. Later the Signal to Noise Ratio of the each frame is determined. The threshold is calculated based on the previous
experiments.
Fig2 : Conventional energy based algorithm - flowchart
The operation of the Voice operated switch is based on the obtained SNR when compared with the assumed
threshold. i.e., when the SNR is greater than threshold then switch gets activated (VOS=1). When the SNR is less than
threshold then the switch deactivates (VOS=0). The noisy speech sample is processed by voice operated switch to allow the
presence of audio in case of speech (VOS=1) and mute when only noise (VOS=0) is present. The simulation and results are
shown in the next section.
The performance of the conventional energy based algorithm was not as anticipated and the result was not
satisfactory, will be discussed in further section.
2.2 Power envelope based algorithm
An algorithm is proposed which detects speech pauses by adaptively tracking minima and maxima in a noisy signal‟s
power envelope both for the broadband signal and for the high-pass and low-pass filtered signal.
Reading a .wav input file
After assuming initial 200ms
as noise only the max & min
values are set
Emin (p) =E (p)
ELP,max(p)=ELP(p)
ELP,max(p)=EHP(p)
FFT (512-pt)
The minimum & maximum value of
each of the three envelopes are
noted.
Creation of LFP and HPF
using fft results
Cal. Signals power envelope of
broadband, Low-pass band, highpass band
(E (p), ELP (p), EHP (p))
The maximum and minimum values are
updated based on current envelope values
Emax (p) =E (p)
EHPmin(p)=ELP(p)
EHPmin(p)=EHP(p)
Based on the above parameters the decision is
made using the following algorithm
The difference between max and min values
are calculated
Δ(p)=Emax(p)− Emin(p)
ΔLP(p)=ELP,max(p)− ELP,min(p)
ΔHP(p)=EHP,max(p)− ELP,min(p)
Fig3: Power envelope based algorithm- Flowchart
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The speech pause detection algorithm calculates the signal‟s temporal power envelope E (p) by summing up the
squares of the spectral components of the input signal in each short-time frame
:
……………. (1)
Here, X (p, ѡk) denotes the spectral component of the noisy input signal at frequency ѡk at time frame. In addition
a low-pass band envelope and a high-pass band envelope are calculated:
:
……… (2)
:
…….. (3)
Where “l” runs over all spectral components up to the cut-off frequency, and “m” runs over the remaining spectral
components. In order to slightly smooth the envelopes, E(ƿ ),
and
are averaged over a few frames by a
recursive low-pass filter of first order with a release time constant ŢE no smoothing is per- formed in case of an increase in
energy (i.e., attack time zero) to avoid smearing over onsets. The algorithm tracks the minimum and maximum value of each
envelope and uses these for the speech pause decision as described by the following scheme.
I. After an assumed 200 ms initial phase of noise only the minimum and maximum values are set as follows:
:
:
:
….… (4)
This guarantees that the minimum envelope values correspond roughly with the noise energy at the beginning.
II. The minimum and maximum values are updated for each of the three envelopes in the following manner.
a)
If the current envelope value is larger than the maximum value for the corresponding envelope, then the maximum value
is set to the current value. Otherwise, the maximum value slowly decays. This is done by a recursive low-pass filter of
first order with a release time constant
, which takes as input the current envelope value.
b) If the current envelope value is smaller than the minimum value for the corresponding envelope, then the minimum
value is set to the current value. Otherwise, the minimum value is slowly raised. This is done by a recursive low-pass
filter of first order with attack time constant
, which takes as input the current envelope value.
III. The differences between the maximum and the minimum values are calculated for each envelope
…… (5)
IV. Three different criteria are introduced of which only one has to be true for making the decision that target speech is not
present in the actual frame: a) the speech pause decision can be made because of a low signal dynamics in both the lowpass and the high-pass band(Syn speech pause); b) the decision can be based on the low-pass band information (LP
Speech Pause); and c) it can be made upon the high-band information (HP Speech Pause). These decision criteria are
derived as follows:
If ΔLP is smaller than some threshold ἠ and ΔHP (ƿ ) < ἠ then it is assumed that only noise is present due to the very
small dynamic range of the signal (Dyn Speech Pause).
b) If a) is not true, it is checked whether ΔLP is bigger than (otherwise the dynamic range in the low-pass band is very
small and it should not receive too much attention no LP Speech Pause). Now, if the difference between the current
and
of the low-pass band envelope is smaller than some fraction pc of ΔLP (which means that the
actual envelope is near its minimum), a closer look at the high-pass band is necessary to support speech pause detection.
a)
Case 1) ΔHP of the high-pass band is smaller than threshold in this case no additional information can be obtained from the
high-pass band because of its small dynamic range. Now, if at least E (p) (the signal‟s envelope) lies in the lower half of its
dynamic range [i.e., in the lower half between
and
the current frame can be assumed to be a speech pause
because of the closeness of the low-pass band energy to its minimum value (LP speech pause) otherwise, however, there is
not enough support for a speech pause decision (No LP Speech Pause).
Case 2) ΔHP is bigger than two times the threshold ἠ .In this case, there is enough dynamic range to pay attention to the
high-pass band. Thus, it is demanded that the difference between the current
and
of the high-pass
envelope is smaller than two times the fraction pc of ΔHP to support the small envelope value in the low-pass band. Then a
noise-only frame is assumed (LP Speech Pause). This demand is not as strict as that for the low-pass band, to account for the
case that the disturbing noise has a rather high-frequency characteristic. But if this condition is not fulfilled, speech may be
present in the actual frame (no LP Speech Pause).
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Case 3) ΔHP Is smaller than two times the threshold ἠ , but bigger than. In this case, which is not as clear as Case 2, it is
only demanded that EHP(ƿ ) (the high-pass Envelope ) lies in the lower half of its dynamic range to support the small
envelope value in the low-pass band Then it is assumed that target speech is absent (LP Speech Pause). However if this
condition is not fulfilled, speech may be present in the actual frame (no LP Speech pause).
c) Condition b) accounts for the case that the disturbing noise has a rather high frequency characteristic, hence the speech
pause detection should mainly be made upon the information in the low-pass band. To account also for the case that it
has be checked but now with reverse roles of the low-pass and the high–pass bands to determine whether target speech
is absent (HP Speech Pause).
Fig 4: Flowchart of the proposed speech pause detection algorithm operating on a single time frame
Fig above gives a flowchart of the proposed power envelope detection algorithm. The flowchart is not fully
symmetrical with respect to LP and HP speech pause detection since several redundant tests are omitted.
Due to its flexible design this novel approach for speech pause detection can easily be adjusted to obtain a rather
low false- alarm rate by adapting the main parameters ἠ and pc. Generally, a Low-false-alarms rate is desirable to reduce
speech distortions in the subsequent noise reduction process. However, this also results in a reduced hit rate.
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During the development of the algorithm noisy signals generated from various different noise types and speech
signals at several SNRs were used for performance verification. Finally, the following values were chosen for the free
parameters: The input signal was digitized with a sampling Frequency of 8000 Hz and partitioned in Hamming-windowed
segments of length 20 ms with 50% overlap. These segments were padded with zeros and a 512-point FFT was performed.
This framework is compatible with most single-microphone noise reduction algorithms which can thus easily be integrated.
Such short segments are motivated by the fact that then the same signal analysis and synthesis as necessary for a real-time
noise reduction environment can be used. The cut-off frequency between low-pass and high-pass band was set to 2 kHz,
motivated by the fact that excluding speech frequencies above 1.9 kHz has a roughly similar effect on speech intelligibility
as excluding those below this value. With these settings a good approximation to the actual dynamic range of the signal and
of its “placement” in the level area under a variety of conditions was achieved. However, systematic variations of these
parameters were not investigated. The threshold was set to 5 dB and the fraction was set to 0.1.
III. SIMULATION RESULTS
In this section the procedure to carry out experiments is discussed and comparison between the proposed algorithm
and conventional energy based algorithm is discussed
3.1 Procedure
The plain speech is recorded at a sampling rate of 8000Hz and is mixed with various noises like white noise, pink
noise, brown noise, helicopter noise etc. with 0db, 3db, 5db, 10db, 15db SNR levels. The algorithms are implemented and
simulated in MATLAB and simulation results are discussed below.
3.2 Simulation results
3.2.1 Conventional energy based algorithm results
The following are the results of conventional energy based algorithm for voice operated switch
Fig 5: Plot of (a) 10dB white noise mixed speech signal (b) Switch on/off for energy based algorithm(c) output
Fig 5 shows the results of voice operated switch when plain speech is mixed with 10 dB white noise and the output
of conventional energy based algorithm.
Fig 6: Plot of (a) 5dB white noise mixed speech signal (b) Switch on/off for energy based algorithm(c) output
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Fig 6 shows the results of voice operated switch when plain speech is mixed with 5 dB white noise and the output of
conventional energy based algorithm.
Fig 7 shows the results of voice operated switch when plain speech is mixed with 10 dB pink noise and the output
of conventional energy based algorithm.
Fig 8 shows the results of voice operated switch when plain speech is mixed with 5 dB helicopter noise and the
output of conventional energy based algorithm.
Fig 7: Plot of (a) 10dB pink noise mixed speech signal (b) Switch on/off for energy based algorithm(c) output
Fig 8: Plot of (a) 5dB helicopter noise mixed speech signal (b) Switch on/off for energy based algorithm(c) output
Fig 9: Plot of (a) 10dB babble noise mixed speech signal (b) Switch on/off for energy based algorithm(c) output
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Fig 9 shows the results of voice operated switch when plain speech is mixed with 10 dB babble noise and the output
of conventional energy based algorithm.
3.2.2 Power envelope based algorithm results
The following are the results of power envelope based algorithm for voice operated switch
Fig 10: Plot of (a) 10dB white noise mixed speech signal (b) Switch on/off for power envelope based algorithm(c)
output
Fig 10 shows the results of voice operated switch when plain speech is mixed with 10 dB white noise and the output
of power envelope based algorithm
Fig 11: Plot of (a) 10dB pink noise mixed speech signal (b) Switch on/off for power envelope based algorithm(c)
output
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Fig 12: Plot of (a) 10dB helicopter noise mixed speech signal (b) Switch on/off for power envelope based algorithm(c)
output
Fig 11 shows the results of voice operated switch when plain speech is mixed with 10 dB pink noise and the output
of power envelope based algorithm
Fig 12 shows the results of voice operated switch when plain speech is mixed with 10 dB helicopter noise and the
output of power envelope based algorithm
Fig 13 shows the results of voice operated switch when plain speech is mixed with 5 dB helicopter noise and the
output of power envelope based algorithm
Fig 13: Plot of (a) 5dB helicopter noise mixed speech signal (b) Switch on/off for power envelope based algorithm(c)
output
There were other simulation results considered and only few of them. In energy based algorithm the switch
activates at few places even when only noise is present. The major disadvantage because of this algorithm is it doesn‟t
perform well due to noise interference or heavy breathing or a side conversation etc.
IV. CONCLUSION
The present VOS technology works based on the conventional energy based algorithm, which works well for white
noise at 10dB, 15dB etc., but results are not promising for helicopter, pink and babble noise. The pilot or co-pilot has to
adjust the threshold (SNR) level which is inside the audio control system (as shown in the figure1) to hear a clear speech
signal. Using the proposed algorithm, the pilot doesn‟t need to change the threshold control every time (unlike conventional
energy based algorithm) to hear the speech signal clearly i.e. the speech is transmitted when speech is detected (VOS=1), it
is muted when noise is present (VOS=0).
From the simulation results and observation it is clearly seen that the power envelope detection based algorithm
gives better and efficient performance when compared with the conventional energy based algorithm. Many research are
however to be analyzed on basis to modify the algorithm to improve the performance on different noise levels. The proposed
power envelope detection algorithm maintains a low and approximately constant false-alarm rate over a wide range of SNRs.
The hit rate decreases only slightly at poorer SNRs.
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