Today model checking is the most useful verification method for real time systems, so there is a serious need for improving its efficiency with respect to both time and resources. In this paper we present a new approach for reducing timed automata. In fact regions of a region automaton are aggregated according to a coarse equivalence class partitioning based on traces. We will show that the proposed algorithm terminates and preserves original timed automaton. Proposed algorithms are implemented by model transformation with Atom3 tool.
Time alignment techniques for experimental sensor dataIJCSES Journal
Experimental data is subject to data loss, which presents a challenge for representing the data with a
proper time scale. Additionally, data from separate measurement systems need to be aligned in order to
use the data cooperatively. Due to the need for accurate time alignment, various practical techniques are
presented along with an illustrative example detailing each step of the time alignment procedure for actual
experimental data from an Unmanned Aerial Vehicle (UAV). Some example MATLAB code is also
provided.
We develop a multi-scale streaming anomaly score that takes into account a family of window sizes, making the algorithm scale invariant across a different types of time series with varying pseudo-periodic structure. We explore different aggregation methods of the multi-scale anomaly score to obtain a final anomaly score. We evaluate the performance on the Yahoo! and Numenta Anomaly Benchmark(NAB) datasets.
Mathematical support for preventive maintenance periodicity optimization of r...Alexander Lyubchenko
The work is aimed to present an approach for estimation of recommended maintenance intervals of radiocommunication devices which is based on the developed Monte Carlo simulation model and the suggested optimality criterion for calculation of the rational periodicity on the basis of obtained values of reliability indexes. The model takes into account the following exploitation factors: sudden, gradual, latent and fictitious failures, human factor of service staff and time parameters of preventive maintenance. The suggested mathematical support allows providing of the high reliability of the exploited equipment.
This poster was created in LaTeX on a Dell Inspiron laptop with a Linux Fedora Core 4 operating system. The background image and the animation snapshots are dxf meshes of elastic waveform solutions, rendered on a Windows machine using 3D Studio Max.
Time alignment techniques for experimental sensor dataIJCSES Journal
Experimental data is subject to data loss, which presents a challenge for representing the data with a
proper time scale. Additionally, data from separate measurement systems need to be aligned in order to
use the data cooperatively. Due to the need for accurate time alignment, various practical techniques are
presented along with an illustrative example detailing each step of the time alignment procedure for actual
experimental data from an Unmanned Aerial Vehicle (UAV). Some example MATLAB code is also
provided.
We develop a multi-scale streaming anomaly score that takes into account a family of window sizes, making the algorithm scale invariant across a different types of time series with varying pseudo-periodic structure. We explore different aggregation methods of the multi-scale anomaly score to obtain a final anomaly score. We evaluate the performance on the Yahoo! and Numenta Anomaly Benchmark(NAB) datasets.
Mathematical support for preventive maintenance periodicity optimization of r...Alexander Lyubchenko
The work is aimed to present an approach for estimation of recommended maintenance intervals of radiocommunication devices which is based on the developed Monte Carlo simulation model and the suggested optimality criterion for calculation of the rational periodicity on the basis of obtained values of reliability indexes. The model takes into account the following exploitation factors: sudden, gradual, latent and fictitious failures, human factor of service staff and time parameters of preventive maintenance. The suggested mathematical support allows providing of the high reliability of the exploited equipment.
This poster was created in LaTeX on a Dell Inspiron laptop with a Linux Fedora Core 4 operating system. The background image and the animation snapshots are dxf meshes of elastic waveform solutions, rendered on a Windows machine using 3D Studio Max.
Parallel Evaluation of Multi-Semi-JoinsJonny Daenen
Presentation given on VLDB 2016: 42nd International Conference on Very Large Data Bases.
Paper: http://dx.doi.org/10.14778/2977797.2977800
ArXiv: https://arxiv.org/abs/1605.05219
Poster: https://zenodo.org/record/61653 (doi 10.5281/zenodo.61653)
Gumbo Software: https://github.com/JonnyDaenen/Gumbo
Abstract
While services such as Amazon AWS make computing power abundantly available, adding more computing nodes can incur high costs in, for instance, pay-as-you-go plans while not always significantly improving the net running time (aka wall-clock time) of queries. In this work, we provide algorithms for parallel evaluation of SGF queries in MapReduce that optimize total time, while retaining low net time. Not only can SGF queries specify all semi-join reducers, but also more expressive queries involving disjunction and negation. Since SGF queries can be seen as Boolean combinations of (potentially nested) semi-joins, we introduce a novel multi-semi-join (MSJ) MapReduce operator that enables the evaluation of a set of semi-joins in one job. We use this operator to obtain parallel query plans for SGF queries that outvalue sequential plans w.r.t. net time and provide additional optimizations aimed at minimizing total time without severely affecting net time. Even though the latter optimizations are NP-hard, we present effective greedy algorithms. Our experiments, conducted using our own implementation Gumbo on top of Hadoop, confirm the usefulness of parallel query plans, and the effectiveness and scalability of our optimizations, all with a significant improvement over Pig and Hive.
I am Bing Jr. I am a Signal Processing Assignment Expert at matlabassignmentexperts.com. I hold a Master's in Matlab Deakin University, Australia. I have been helping students with their assignments for the past 9 years. I solve assignments related to Signal Processing.
Visit matlabassignmentexperts.com or email info@matlabassignmentexperts.com. You can also call on +1 678 648 4277 for any assistance with Signal Processing Assignments.
A Detailed Comparative Study between Reduced Order Cumming Observer & Reduced...IJERD Editor
In this article a detailed comparative study between two well known observer design methodologies
namely, reduced order Cumming observer & reduced order Das &Ghoshal observer has been presented. The
necessary equations & conditions corresponding to these two types of observers are discussed in brief.
Thereafter with the help of a structure wise comparison the similarities & dissimilarities between the above
mentioned methods are explained in details. Finally a performance wise comparison between these two is shown
using proper numerical example & illustrations in open loop as well as closed loop.
This presentation on Pseudo Random Number Generator enlists the different generators, their mechanisms and the various applications of random numbers and pseudo random numbers in different arenas.
Viene presentato e discusso (in inglese) in dettaglio l'utilizzo della piattaforma EIAGRID/SmartGEO in due casi studio significativi per le applicazioni geotecniche e ambientali. Al termine, l'utente interessato dovrebbe essere in grado di utilizzare in modo autonomo la piattaforma attraverso il portale SmartGEO.
Parallel Evaluation of Multi-Semi-JoinsJonny Daenen
Presentation given on VLDB 2016: 42nd International Conference on Very Large Data Bases.
Paper: http://dx.doi.org/10.14778/2977797.2977800
ArXiv: https://arxiv.org/abs/1605.05219
Poster: https://zenodo.org/record/61653 (doi 10.5281/zenodo.61653)
Gumbo Software: https://github.com/JonnyDaenen/Gumbo
Abstract
While services such as Amazon AWS make computing power abundantly available, adding more computing nodes can incur high costs in, for instance, pay-as-you-go plans while not always significantly improving the net running time (aka wall-clock time) of queries. In this work, we provide algorithms for parallel evaluation of SGF queries in MapReduce that optimize total time, while retaining low net time. Not only can SGF queries specify all semi-join reducers, but also more expressive queries involving disjunction and negation. Since SGF queries can be seen as Boolean combinations of (potentially nested) semi-joins, we introduce a novel multi-semi-join (MSJ) MapReduce operator that enables the evaluation of a set of semi-joins in one job. We use this operator to obtain parallel query plans for SGF queries that outvalue sequential plans w.r.t. net time and provide additional optimizations aimed at minimizing total time without severely affecting net time. Even though the latter optimizations are NP-hard, we present effective greedy algorithms. Our experiments, conducted using our own implementation Gumbo on top of Hadoop, confirm the usefulness of parallel query plans, and the effectiveness and scalability of our optimizations, all with a significant improvement over Pig and Hive.
I am Bing Jr. I am a Signal Processing Assignment Expert at matlabassignmentexperts.com. I hold a Master's in Matlab Deakin University, Australia. I have been helping students with their assignments for the past 9 years. I solve assignments related to Signal Processing.
Visit matlabassignmentexperts.com or email info@matlabassignmentexperts.com. You can also call on +1 678 648 4277 for any assistance with Signal Processing Assignments.
A Detailed Comparative Study between Reduced Order Cumming Observer & Reduced...IJERD Editor
In this article a detailed comparative study between two well known observer design methodologies
namely, reduced order Cumming observer & reduced order Das &Ghoshal observer has been presented. The
necessary equations & conditions corresponding to these two types of observers are discussed in brief.
Thereafter with the help of a structure wise comparison the similarities & dissimilarities between the above
mentioned methods are explained in details. Finally a performance wise comparison between these two is shown
using proper numerical example & illustrations in open loop as well as closed loop.
This presentation on Pseudo Random Number Generator enlists the different generators, their mechanisms and the various applications of random numbers and pseudo random numbers in different arenas.
Viene presentato e discusso (in inglese) in dettaglio l'utilizzo della piattaforma EIAGRID/SmartGEO in due casi studio significativi per le applicazioni geotecniche e ambientali. Al termine, l'utente interessato dovrebbe essere in grado di utilizzare in modo autonomo la piattaforma attraverso il portale SmartGEO.
Discretizing of linear systems with time-delay Using method of Euler’s and Tu...IJERA Editor
Delays deteriorate the control performance and could destabilize the overall system in the theory of discretetime
signals and dynamic systems. Whenever a computer is used in measurement, signal processing or control
applications, the data as seen from the computer and systems involved are naturally discrete-time because a
computer executes program code at discrete points of time. Theory of discrete-time dynamic signals and systems
is useful in design and analysis of control systems, signal filters, state estimators and model estimation from
time-series of process data system identification. In this paper, a new approximated discretization method and
digital design for control systems with delays is proposed. System is transformed to a discrete-time model with
time delays. To implement the digital modeling, we used the z-transfer functions matrix which is a useful model
type of discrete-time systems, being analogous to the Laplace-transform for continuous-time systems. The most
important use of the z-transform is for defining z-transfer functions matrix is employed to obtain an extended
discrete-time. The proposed method can closely approximate the step response of the original continuous timedelayed
control system by choosing various of energy loss level. Illustrative example is simulated to demonstrate
the effectiveness of the developed method.\
A review of literature shows that there is a variety of works studying coverage path planning in several autonomous robotic applications. In this work, we propose a new approach using Markov Decision Process to plan an optimum path to reach the general goal of exploring an unknown environment containing buried mines. This approach, called Goals to Goals Area Coverage on-line Algorithm, is based on a decomposition of the state space into smaller regions whose states are considered as goals with the same reward value, the reward value is decremented from one region to another according to the desired search mode. The numerical simulations show that our approach is promising for minimizing the necessary cost-energy to cover the entire area.
Discrete wavelet transform-based RI adaptive algorithm for system identificationIJECEIAES
In this paper, we propose a new adaptive filtering algorithm for system identifica- tion. The algorithm is based on the recursive inverse (RI) adaptive algorithm which suffers from low convergence rates in some applications; i.e., the eigenvalue spread of the autocorrelation matrix is relatively high. The proposed algorithm applies discrete-wavelet transform (DWT) to the input signal which, in turn, helps to overcome the low convergence rate of the RI algorithm with relatively small step-size(s). Different scenarios has been investigated in different noise environments in system identification setting. Experiments demonstrate the advantages of the proposed DWT recursive inverse (DWT-RI) filter in terms of convergence rate and mean-square-error (MSE) compared to the RI, discrete cosine transform LMS (DCT-LMS), discretewavelet transform LMS (DWT-LMS) and recursive-least-squares (RLS) algorithms under same conditions.
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.
A Review: Compensation of Mismatches in Time Interleaved Analog to Digital Co...IJERA Editor
The execution of today's correspondence frameworks is exceedingly subject to the utilized Analog-to-Digital converters (ADCs), and with a specific end goal to give more flexibility and exactness to the developing correspondence innovations, superior-ADCs are needed. In this respect, the time-interleaved operation of an exhibit of ADCs (TI-ADC) might be a sensible result. A TI-ADC can build its throughput by utilizing M channel ADCs or sub converters in parallel and examining the data motion in a period-interleaved way. In any case, the execution of a TI-ADC gravely suffers from the bungles around the channel ADCs. In this paper we survey the advancement in the configuration of low-intricacy advanced remedy structures and calculations for time-interleaved ADCs in the course of the most recent five years. We devise a discrete-time model, state the outline issue, and finally infer the calculations and structures. Specifically, we examine proficient calculations to outline time-differing remedy filters and additionally iterative structures using polynomial based filters. Thusly, the remuneration structure may be utilized to repay time-differing recurrence reaction befuddles in time-interleaved ADCs, and in addition to remake uniform examples from nonuniformly tested indicators. We examine the recompense structure, research its execution, and exhibit requisition zones of the structure through various illustrations. At long last, we give a standpoint to future examination questions.
Compensation of Data-Loss in Attitude Control of Spacecraft Systems rinzindorjej
In this paper, a comprehensive comparison of two robust estimation techniques namely, compensated closed-loop Kalman filtering and open-loop Kalman filtering is presented. A common problem of data loss in a real-time control system is investigated through these two schemes. The open-loop scheme, dealing with the data-loss, suffers from several shortcomings. These shortcomings are overcome using compensated scheme, where an accommodating observation signal is obtained through linear prediction technique -- a closed-loop setting and is adopted at a posteriori update step. The calculation and employment of accommodating observation signal causes computational complexity. For simulation purpose, a linear time invariant spacecraft model is however, obtained from the nonlinear spacecraft attitude dynamics through linearization at nonzero equilibrium points -- achieved off-line through Levenberg-Marguardt iterative scheme. Attempt has been made to analyze the selected example from most of the perspectives in order to display the performance of the two techniques.
Action Trajectory Reconstruction for Controlling of Vehicle Using SensorsIOSR Journals
Abstract: Inertial sensors, such as accelerometers and gyro-scopes, are rarely used by themselves to compute
velocity and position as each requires the integration of very noisy data. The variance and bias in the resulting
position and velocity estimates grow un-bounded in time. This paper proposes a solution to provide a de-biased
and de-noised estimation of position and velocity of moving vehicle actions from accelerometer measurements.
The method uses a continuous wavelet transform applied to the measurements recursively to provide reliable
action trajectory reconstruction. The results are presented from experiments performed with a MEMS accelerometer
and gyroscope.
Keywords: Action trajectory, continuous wavelet transform, inertial measurement unit.
SLIDING WINDOW SUM ALGORITHMS FOR DEEP NEURAL NETWORKSIJCI JOURNAL
Sliding window sums are widely used for string indexing, hashing and time series analysis. We have
developed a family of the generic vectorized sliding sum algorithms that provide speedup of O(P/w) for
window size w and number of processors P. For a sum with a commutative operator the speedup is
improved to O(P/log(w)). Even more important, our algorithms exhibit efficient memory access patterns. In
this paper we study the application of sliding sum algorithms to the training and inference of Deep Neural
Networks. We demonstrate how both pooling and convolution primitives could be expressed as sliding
sums and evaluated by the compute kernels with a shared structure. We show that the sliding sum
convolution kernels are more efficient than the commonly used GEMM kernels on CPUs and could even
outperform their GPU counterparts.
Adaptive synchronous sliding control for a robot manipulator based on neural ...IJECEIAES
Robot manipulators have become important equipment in production lines, medical fields, and transportation. Improving the quality of trajectory tracking for
robot hands is always an attractive topic in the research community. This is a
challenging problem because robot manipulators are complex nonlinear systems
and are often subject to fluctuations in loads and external disturbances. This
article proposes an adaptive synchronous sliding control scheme to improve trajectory tracking performance for a robot manipulator. The proposed controller
ensures that the positions of the joints track the desired trajectory, synchronize
the errors, and significantly reduces chattering. First, the synchronous tracking
errors and synchronous sliding surfaces are presented. Second, the synchronous
tracking error dynamics are determined. Third, a robust adaptive control law is
designed,the unknown components of the model are estimated online by the neural network, and the parameters of the switching elements are selected by fuzzy
logic. The built algorithm ensures that the tracking and approximation errors
are ultimately uniformly bounded (UUB). Finally, the effectiveness of the constructed algorithm is demonstrated through simulation and experimental results.
Simulation and experimental results show that the proposed controller is effective with small synchronous tracking errors, and the chattering phenomenon is
significantly reduced.
Motion planning and controlling algorithm for grasping and manipulating movin...ijscai
Many of the robotic grasping researches have been focusing on stationary objects. And for dynamic moving
objects, researchers have been using real time captured images to locate objects dynamically. However,
this approach of controlling the grasping process is quite costly, implying a lot of resources and image
processing.Therefore, it is indispensable to seek other method of simpler handling… In this paper, we are
going to detail the requirements to manipulate a humanoid robot arm with 7 degree-of-freedom to grasp
and handle any moving objects in the 3-D environment in presence or not of obstacles and without using
the cameras. We use the OpenRAVE simulation environment, as well as, a robot arm instrumented with the
Barrett hand. We also describe a randomized planning algorithm capable of planning. This algorithm is an
extent of RRT-JT that combines exploration, using a Rapidly-exploring Random Tree, with exploitation,
using Jacobian-based gradient descent, to instruct a 7-DoF WAM robotic arm, in order to grasp a moving
target, while avoiding possible encountered obstacles . We present a simulation of a scenario that starts
with tracking a moving mug then grasping it and finally placing the mug in a determined position, assuring
a maximum rate of success in a reasonable time.
Multivariable Parametric Modeling of a Greenhouse by Minimizing the Quadratic...TELKOMNIKA JOURNAL
This paper concerns the identification of a greenhouse described in a multivariable linear system
with two inputs and two outputs (TITO). The method proposed is based on the least squares identification
method, without being less efficient, presents an iterative calculation algorithm with a reduced
computational cost. Moreover, its recursive character allows it to overcome, with a good initialization, slight
variations of parameters, inevitable in a real multivariable process. A comparison with other method s
recently proposed in the literature demonstrates the advantage of this method. Simulations obtained will be
exposed to showthe effectiveness and application of the method on multivariable systems.
In order to achieve the wide range of the robotic application it is necessary to provide iterative motions
among points of the goals. For instance, in the industry mobile robots can replace any components between
a storehouse and an assembly department. Ammunition replacement is widely used in military services.
Working place is possible in ports, airports, waste site and etc. Mobile agents can be used for monitoring if
it is necessary to observe control points in the secret place. The paper deals with path planning programme
for mobile robots. The aim of the research paper is to analyse motion-planning algorithms that contain the
design of modelling programme. The programme is needed as environment modelling to obtain the
simulation data. The simulation data give the possibility to conduct the wide analyses for selected
algorithm. Analysis means the simulation data interpretation and comparison with other data obtained
using the motion-planning. The results of the careful analysis were considered for optimal path planning
algorithms. The experimental evidence was proposed to demonstrate the effectiveness of the algorithm for
steady covered space. The results described in this work can be extended in a number of directions, and
applied to other algorithms.
Similar to REDUCING TIMED AUTOMATA: A NEW APPROACH (20)
INFORMATION THEORY BASED ANALYSIS FOR UNDERSTANDING THE REGULATION OF HLA GEN...ijistjournal
Considering information entropy (IE), HLA surface expression (SE) regulation phenomenon is considered as information propagation channel with an amount of distortion. HLA gene SE is considered as sink regulated by the inducible transcription factors (TFs) (source). Previous work with a certain number of bin size, IEs for source and receiver is computed and computation of mutual information characterizes the dependencies of HLA gene SE on some certain TFs in different cells types of hematopoietic system under the condition of leukemia. Though in recent time information theory is utilized for different biological knowledge generation and different rules are available in those specific domains of biomedical areas; however, no such attempt is made regarding gene expression regulation, hence no such rule is available. In this work, IE calculation with varying bin size considering the number of bins is approximately half of the sample size of an attribute also confirms the previous inferences.
Call for Research Articles - 5th International Conference on Artificial Intel...ijistjournal
5th International Conference on Artificial Intelligence and Machine Learning (CAIML 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of Artificial Intelligence and Machine Learning. The Conference looks for significant contributions to all major fields of the Artificial Intelligence, Machine Learning in theoretical and practical aspects. The aim of the Conference is to provide a platform to the researchers and practitioners from both academia as well as industry to meet and share cutting-edge development in the field.
Authors are solicited to contribute to the conference by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in the areas of Computer Science, Engineering and Applications.
Online Paper Submission - International Journal of Information Sciences and T...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
SYSTEM IDENTIFICATION AND MODELING FOR INTERACTING AND NON-INTERACTING TANK S...ijistjournal
System identification from the experimental data plays a vital role for model based controller design. Derivation of process model from first principles is often difficult due to its complexity. The first stage in the development of any control and monitoring system is the identification and modeling of the system. Each model is developed within the context of a specific control problem. Thus, the need for a general system identification framework is warranted. The proposed framework should be able to adapt and emphasize different properties based on the control objective and the nature of the behavior of the system. Therefore, system identification has been a valuable tool in identifying the model of the system based on the input and output data for the design of the controller. The present work is concerned with the identification of transfer function models using statistical model identification, process reaction curve method, ARX model, genetic algorithm and modeling using neural network and fuzzy logic for interacting and non interacting tank process. The identification technique and modeling used is prone to parameter change & disturbance. The proposed methods are used for identifying the mathematical model and intelligent model of interacting and non interacting process from the real time experimental data.
Call for Research Articles - 4th International Conference on NLP & Data Minin...ijistjournal
4th International Conference on NLP & Data Mining (NLDM 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of Natural Language Computing and Data Mining.
Authors are solicited to contribute to the conference by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in the following areas, but are not limited to.
Research Article Submission - International Journal of Information Sciences a...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
Call for Papers - International Journal of Information Sciences and Technique...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
Implementation of Radon Transformation for Electrical Impedance Tomography (EIT)ijistjournal
Radon Transformation is generally used to construct optical image (like CT image) from the projection data in biomedical imaging. In this paper, the concept of Radon Transformation is implemented to reconstruct Electrical Impedance Topographic Image (conductivity or resistivity distribution) of a circular subject. A parallel resistance model of a subject is proposed for Electrical Impedance Topography(EIT) or Magnetic Induction Tomography(MIT). A circular subject with embedded circular objects is segmented into equal width slices from different angles. For each angle, Conductance and Conductivity of each slice is calculated and stored in an array. A back projection method is used to generate a two-dimensional image from one-dimensional projections. As a back projection method, Inverse Radon Transformation is applied on the calculated conductance and conductivity to reconstruct two dimensional images. These images are compared to the target image. In the time of image reconstruction, different filters are used and these images are compared with each other and target image.
Online Paper Submission - 6th International Conference on Machine Learning & ...ijistjournal
6th International Conference on Machine Learning & Applications (CMLA 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of on Machine Learning & Applications.
Authors are solicited to contribute to the conference by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in the following areas, but are not limited to.
Submit Your Research Articles - International Journal of Information Sciences...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
BER Performance of MPSK and MQAM in 2x2 Almouti MIMO Systemsijistjournal
Almouti published the error performance of the 2x2 space-time transmit diversity scheme using BPSK. One of the key techniques employed for correcting such errors is the Quadrature amplitude modulation (QAM) because of its efficiency in power and bandwidth.. In this paper we explore the error performance of the 2x2 MIMO system using the Almouti space-time codes for higher order PSK and M-ary QAM. MATLAB was used to simulate the system; assuming slow fading Rayleigh channel and additive white Gaussian noise. The simulated performance curves were compared and evaluated with theoretical curves obtained using BER tool on the MATLAB by setting parameters for random generators. The results shows that the technique used do find a place in correcting error rates of QAM system of higher modulation schemes. The model can equally be used not only for the criteria of adaptive modulation but for a platform to design other modulation systems as well.
Online Paper Submission - International Journal of Information Sciences and T...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
Call for Papers - International Journal of Information Sciences and Technique...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
International Journal of Information Sciences and Techniques (IJIST)ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
BRAIN TUMOR MRIIMAGE CLASSIFICATION WITH FEATURE SELECTION AND EXTRACTION USI...ijistjournal
Feature extraction is a method of capturing visual content of an image. The feature extraction is the process to represent raw image in its reduced form to facilitate decision making such as pattern classification. We have tried to address the problem of classification MRI brain images by creating a robust and more accurate classifier which can act as an expert assistant to medical practitioners. The objective of this paper is to present a novel method of feature selection and extraction. This approach combines the Intensity, Texture, shape based features and classifies the tumor as white matter, Gray matter, CSF, abnormal and normal area. The experiment is performed on 140 tumor contained brain MR images from the Internet Brain Segmentation Repository. The proposed technique has been carried out over a larger database as compare to any previous work and is more robust and effective. PCA and Linear Discriminant Analysis (LDA) were applied on the training sets. The Support Vector Machine (SVM) classifier served as a comparison of nonlinear techniques Vs linear ones. PCA and LDA methods are used to reduce the number of features used. The feature selection using the proposed technique is more beneficial as it analyses the data according to grouping class variable and gives reduced feature set with high classification accuracy.
Research Article Submission - International Journal of Information Sciences a...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
A MEDIAN BASED DIRECTIONAL CASCADED WITH MASK FILTER FOR REMOVAL OF RVINijistjournal
In this paper A Median Based Directional Cascaded with Mask (MBDCM) filter has been proposed, which is based on three different sized cascaded filtering windows. The differences between the current pixel and its neighbors aligned with four main directions are considered for impulse detection. A direction index is used for each edge aligned with a given direction. Minimum of these four direction indexes is used for impulse detection under each masking window. Depending on the minimum direction indexes among these three windows new value to substitute the noisy pixel is calculated. Extensive simulations showed that the MBDCM filter provides good performances of suppressing impulses from both gray level and colored benchmarked images corrupted with low noise level as well as for highly dense impulses. MBDCM filter gives better results than MDWCMM filter in suppressing impulses from highly corrupted digital images.
DECEPTION AND RACISM IN THE TUSKEGEE SYPHILIS STUDYijistjournal
During the twentieth century (1932-1972), white physicians representing the United States government
conducted a human experiment known as the Tuskegee Syphilis Study on black syphilis patients in Macon
County, Alabama. The creators of the study, who supported the idea of black inferiority and the concept
that black people’s bodies functioned differently from white people’s, observed the effects of a disease
called syphilis on untreated black patients in order to collect data for further research on syphilis. Black
individuals involved with the study believed that they were receiving treatment, although in truth,
treatments for syphilis were purposely held back from them. Not only this, but fluids from their bodies, such
as blood and spinal fluid, were extracted to serve as research material without their awareness of the
purpose of the collection. The physicians justified their approach by positioning it as mere observation,
asserting that they were not actively intervening with the patients participating in the experiment. However,
despite their claims of passivity, these white physicians engaged in various morally improper actions,
including deceit, which ultimately resulted in the deaths of numerous black patients who might have had a
chance at survival.
Online Paper Submission - International Journal of Information Sciences and T...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
A NOVEL APPROACH FOR SEGMENTATION OF SECTOR SCAN SONAR IMAGES USING ADAPTIVE ...ijistjournal
The SAR and SAS images are perturbed by a multiplicative noise called speckle, due to the coherent nature of the scattering phenomenon. If the background of an image is uneven, the fixed thresholding technique is not suitable to segment an image using adaptive thresholding method. In this paper a new Adaptive thresholding method is proposed to reduce the speckle noise, preserving the structural features and textural information of Sector Scan SONAR (Sound Navigation and Ranging) images. Due to the massive proliferation of SONAR images, the proposed method is very appealing in under water environment applications. In fact it is a pre- treatment required in any SONAR images analysis system. The results obtained from the proposed method were compared quantitatively and qualitatively with the results obtained from the other speckle reduction techniques and demonstrate its higher performance for speckle reduction in the SONAR images.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
1. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
DOI : 10.5121/ijist.2012.2402 15
REDUCING TIMED AUTOMATA: A NEW APPROACH
Ilham KITOUNI, Hiba HACHICHI, Kenza BOUAROUDJ, Djamel Eddine
SAIDOUNI
MISC Laboratory, University Mentouri, Constantine, 25000, Algeria
{kitouni,hachichi,bouaroudj,saidouni}@misc-umc.org
ABSTRACT
Today model checking is the most useful verification method for real time systems, so there is a serious
need for improving its efficiency with respect to both time and resources. In this paper we present a new
approach for reducing timed automata. In fact regions of a region automaton are aggregated according to
a coarse equivalence class partitioning based on traces. We will show that the proposed algorithm
terminates and preserves original timed automaton. Proposed algorithms are implemented by model
transformation with Atom3 tool.
KEYWORDS
Real time systems, Timed automata, Region automata, model transformation, ATOM3
1. INTRODUCTION
Nowadays, technology is looking for distributed applications to develop and increase its domains
(network, telecommunication…etc). This kind of applications is known by their complexity.
Formal modelling based methods are the most used technique to deal with concurrent and
distributed systems because of their ability to describe system behaviour without ambiguity.
It is well known that the quality of validation techniques and results depend on the quality of the
models used for specification. A particular interest is given to these formalisms for their aptitude
to be implemented in real world.
The model-checking consists to verify certain properties for the desired system. This later is
modelled by timed automata. This technique has proven its efficiency over several years by
validating protocols and circuits. In practice, due the consideration of real time quantitative
aspect; verification and validation algorithms are hard to implement. These algorithms are based
on region automata; they have been used for solving several problems like automaton emptiness,
system supervising and system testing [9][11][18] [25][15][13].
Recall that the execution of a timed automaton is infinite. The idea of region automaton consists
of partitioning the states space into finite regions, thus the graph which imitates the behavior of
the initial automaton is constructed. The states of the automaton belonging to the same region are
equivalent according to a well-defined relation (relation on clocks valuation).
Nevertheless, the complexity of implementing region automata is exponential with respect to both
clocks number and length timing constraints [1][7][8][20][27].
2. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
16
In this context, we define an aggregation operation on region automaton localities using a Bi-
relation which can exist between them. This equivalence relation is used for grouping equivalent
regions. It is obvious that this aggregation reduces the number of graph localities. For this
purpose we propose an algorithm implementing the aggregation relation starting from an initial
partitioning of localities. The generated aggregated regions automaton preserves the reachability
property. Consequently the reachability question on timed automaton states is reduced to the
reachability question on the aggregated timed automaton. Therefore the language recognized by
both automata is the same. In [2], the timed automata based model-checking of TCTL logic
properties has been proven PSPACE complete. Since the aggregation algorithm reduces the
region, the complexity doesn’t increase. To experiment our approach, the proposed algorithm is
implemented using model transformation based approaches.
The rest of the paper is organized as follows: after presenting related work in section 2, timed
automata and region automata are presented in sections 3 and 4 respectively. In sections 5 we
develop some intermediaries’ results leading to the aggregation algorithm. Section 6 presents the
algorithm. In section 7 we present the implementation and example to illustrate our approach.
Finally we conclude the paper in section 8.
2. RELATED WORKS
Several works related to the minimization of timed automata have been proposed for avoiding the
state space explosion problem. In [17], it has been shown that the formalization is able to identify
symbolically timed properties from the timed automata. While in other work, the states space of
the timed automata is reduced by a minimization during the construction of the regions graph,
using a bissimulation relation on clock regions [2][26]. A minimization of timed automata
resources, such as the clocks number or the constraints size by eliminating the inactive clocks is
considered in [11]. It is based on a static analysis technique; however, it is judged to be not
powerful for addressing the undecidability problem of timed automata. In [28], the reduction of
the clocks number or constraints size can be made algorithmically. More recent work shows that
the undecidability problem persists [14].
On the other hand, other works suggest the concept of grid. In fact, the grid covers the underlying
dense time space of timed automata, mapping points in states space into a single representative of
each grid region. The chosen grid size of a timed automaton is an integer number. The grid
automaton G(A;d) is defined as a sub automaton of a timed automaton A that only contains clock
valuations that are multiples of d (where 0<d<1). G(A;d) represents a discrete version of A with
discretization step d. The size of grid depends on the clocks number and the size of states set in
the automaton. However, since the number of regions in real specifications is very large, it should
be clear that the step size becomes small. Consequently, the algorithm which is theoretically
exhaustive, is highly impractical [19][23]. The minimization principle of previous approaches is
based on clock regions handling, to go off initial fine-grained regions, in order to achieve more
compact regions. In contrast to this, our proposal is based on the actions labeling transitions,
consequently reasoning on the traces and the reachable states of the Timed Automata.
Even the idea seems simple; it has the advantage to be compatible with previous approaches.
Indeed, under certain conditions, reduction can be spectacular. Obviously, our approach may be
used together with previous.
3. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
17
3. TIMED AUTOMATA
Timed automata have been introduced in 90’s for modeling real-time systems. It is a finite
untimed automaton to which is associated a finite set of positive real-valued variables said clocks
[3][7].
Let H be a finite set of clocks, we assume the time domain be the set R+
of positive real numbers.
We note Φ a finite conjunction of constraints of the form x»k where x∈H, k∈ Q+
and » ∈ {≤, <,
=, >, ≥}.
A valuation v over H is a mapping v : H to R+
. Let h be a subset of clocks, the valuation v[h
← 0]
resets each clock of h to 0, i.e. maps each clock x in h to 0, and each other clock x to v(x). Let d
be a positive real, the valuation v+d maps every clock x to v(x) + d. The constraints are
interpreted over valuations; we write v|= g if the valuation v satisfies the clock constraint g. It is
defined in a natural way by v|= x»c whenever v(x)»c and v|=(g1˄g2) whenever v|= g1 and v|=
g2.
Definition 3.1. Let ∑ be a finite alphabet, a timed automaton over ∑ is a tuple ( )
F
S
T
H
s
S
A ,
,
,
, 0
=
where S is a finite set of states, s0 in S is the initial state, H is a finite set of clocks,
S
S
T H
×
×
Σ
×
Φ
×
∈ 2 is a finite set of edges, SF is the set of final states.
A transition (s,g,a,h,s’) ∈ T represents a change of location from s ∈ S to s’ ∈ S on symbol a ∈
∑. The clock constraint g ∈ Φ (guard) specifies when the transition is enabled and the set h ⊆ H
gives the set of clocks to be reset by this transition.
The semantic of timed automata is given as timed transition systems. Let A be a timed automaton
over ∑, the corresponding timed transition system is ( )
,
, 0 →
= q
Q
SA where:
• Q=S×R+
is the set of states also called configurations,
• q0 = (s0, 0) is the initial state,
• The transition relation is composed of the following moves: Delay moves:
( ) ( )
d
v
s
v
s d
+
→
,
, for every d in R+
and Discrete moves: ( ) ( )
'
,
'
, v
s
v
s a
→
iff there exist some
transition (s, g, a, h, s’) ∈ T such that [ ]
0
'
and ←
=
= h
v
v
g
v .
In practice, several models are based on timed automata. We reference the classical timed
automata of Alur and Dill and some extensions of this model.
4. REGION AUTOMATA
The region automata are the automata which reproduce the infinite execution of timed automata
by a finite set of transitions. Also it is well known that in the verification by model-checking,
testing and supervision the region automata are very used because they allow de-timing the
specification. We resume in this section the classical definition of region automata [1].
4.1 Clock Regions
The valuations of a finite set of clocks are a region, such as from two valuations of the same
region, the same transitions are enabled.
4. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
18
Definition4.1. Let A be a timed automaton, the set of standard regions, Ω of A is the set of
equivalence classes’ relation, noted ≡. This relation is defined over the clocks valuations as
follows:
(1)
Mx is the maximum constants appearing in the constraints on clock x and for any real c, │c│
denotes the integral part of c, frac(c) denotes the fractional part of c.
For example, we consider a set H of two clocks x and y where Mx= 3 and My= 1. So we have 38
regions, Figure 1.
Figure 1. Standard regions.
Properties: Two valuations of the same region must satisfy the same constraints. The relation ≡
satisfies the following property:
(2)
The equivalence of regions is compatible with the variation of time; it is therefore possible to
define a successor function on regions. We note succ(r), all successors of the region r by lapsing
time. All of regions r satisfies the following property: +
∈
∃
∈
∃
⇔
∈ R
.
)
(
' c
r
r
succ
r υ such as
'
r
c∈
+
υ . Finally, we note that any clock region can be represented as: {x = k: (k = 0,1, ... , Mx) or
k-1 <x < k: (k = 1, ... , Mx) or k <x: (k = Mx)}.
Example: The successors of r1 [(2 <x <3),(0 <y <x <1)] are: r2 [(x=3), (0<y<1)], r3 [(x>3),
(0<y<1)], r4 [(x>3), (y=1)], r5 [(x>3), (y>1)].
4.2 Region Automaton
Definition 4.2. Let A = (S, s0, H, T, SF) be a timed automaton defined by a timed transition system.
The region automaton RA(A) = (L, l0, TR) over ∑corresponding to A is a finite automaton defined
as follows: all localities of RA(A) are of the form lij = (si, rj) where si is a state and rj is a clock
region. The initial locality is l0= (s0, r0). The set of localities is noted L. The set of transitions TR
is,
( )
( )
≤
⇔
≤
⇒
≤
≤
>
⇔
>
=
∈
∀
≡
))
(
'
(
))
(
'
(
))
(
(
))
(
(
)
(
'
and
)
(
)
)
(
'
)
(
(
where
)
(
'
)
(
)
,
(
if
'
y
v
frac
x
v
frac
y
v
frac
x
v
frac
M
y
v
M
x
v
M
x
v
M
x
v
x
v
x
v
H
y
x
v
v
y
x
x
x
'
'
as
such
'
,
and
'
:
in
g
evry
for
then
'
c
v
c
v
R
c
R
c
G
v
G
v
A
v
v
+
≡
+
∈
∃
∈
∀
=
⇔
=
≡
+
+
5. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
19
(3)
(4)
5. AGGREGATION PRINCIPLE
In this section, we define an aggregation operation, which can be considered as a particular
determinization. The indeterminism considered here is due to the construction of the initial region
automaton [15], so it is not inherent to the system.
The principle of the aggregation operation consists to find and regroup localities which verify the
following conditions:
• For any input transition of a locality l1 there exist input transitions to a locality l2, where
their outgoing are coming from the same source locality and have the same label. This second
transition is called “forward mirror” of the first.
• For any output transition of a locality l1 there exist output transitions from a locality l2
where their outgoing goes to the same target locality and have the same label. This second
transition is called “backward mirror” of the first.
• Localities are grouped if their sets “forward mirror” and “backward mirror” matches.
5.1 Notations and Definitions
Let τi be a transition of a timed transition system. α(τi) (resp. β(τi)) denotes the source locality of
τi (resp. the target locality of τi); the label of the transition τi is given by λ(τi).
Definition 5.1. The set of the input transition in a locality lij is in(lij) = {τj | β(τi)= lij}. The set of
the output transition from a locality lij is out(lij) = {τj | α(τi) = lij}.
Definition 5.2. “forward mirror” is a set lij of localities defined as follows:
(5)
Definition 5.3. “backward mirror” is a set lij of localities defined as follows:
(6)
Definition 5.4. A set of grouped localities with lij, noted RL(lij), is defined as follows:
(7)
Definition 5.5. IR is a grouping relation on localities; it is defined as follows:
)
RL(
y
iff
IR
y)
(x,
/
L
y
x, x
∈
∈
∈
∀ . (8)
( ) S
s
iff
locality
terminal
a
is
,
s
l F
i
F
ij ∈
= j
r
[ ]
→
→
←
=
⊆
∈
∃
∈
∃
=
=
0
"
'
a
as
such
)
(
"
a
'
,
,
)
'
,
'
(
)
,
(
'
/
'
h
r
r
nd
g
r
r
succ
r
nd
T
s
h
a
g
s
r
s
a
r
s
t
t
R
T
( )
)
(
)
'
(
)
(
)
'
(
as
such
)
ik
l
(
'
),
ij
l
(
/
ik
l
=
∧
=
∈
∃
∈
∀
=
τ
α
τ
α
τ
λ
τ
λ
τ
τ in
in
l
FM ij
( )
=
∧
=
∈
∃
∈
∀
=
)
(
)
'
(
)
(
)
'
(
as
such
)
ik
l
(
'
),
ij
l
(
/
ik
l
τ
β
τ
β
τ
λ
τ
λ
τ
τ out
out
l
BM ij
elsewhere
locality
terminal
a
is
if
/
)
RL(
∈
∈
=
)
ij
BM(l
)
ij
FM(l
ik
l
ik
l
)
ij
FM(L
ik
l
l
ij
l ik I
6. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
20
The Bi-relation defined above is an equivalence relation, which allows defining the equivalence
classes of the grouped localities. Indeed, IR is a reflexive relation: any locality x is grouped with
itself because it has the same “forward mirror” and “backward mirror” as x. If x is grouped with y
then x has the same “forward mirror” and “backward mirror” as y: It is evident that y has the same
“forward mirror” and “backward mirror” as x according to definitions above, it is thus
symmetrical. (x, y) are grouped and (y, z) are grouped, by definitions, (x, z) are grouped then the
relation is transitive. □
Definition 5.6. The summation of clocks regions is an operation defined on the set of regions as
follows:
(9)
on a clock x specifying a clock region is extended by the following form: {α≤x≤β : (α<β<Mx
The union operation ∪ is defined like the union on integer intervals. Note that the form of
constraints)}. The new construction is a region; it follows the same semantic as region initially
considered.
Definition 5.7. The Aggregated regions automaton ARA(A)=(LA
, l0
A
, TAR) of the timed automaton
A is a transition system over the alphabet ∑ defined as follows: The localities of ARA(A) are of
the form (s,ȓ) where s∈ S and ȓ is a region, the initial locality is of the form (s0,ȓ0) such as ȓ0=r0
and the set of transitions TAR is:
TAR =TR-TSP where TSP is the set of redundant transitions resulting after the aggregation
operation.
6. AGGREGATION ALGORITHM
The aggregation operation consists to find localities to be grouped and their replacement by a new
locality. This locality has the same name state; its region is the summation of regions of grouped
localities; the entering and exiting transitions are substituted with new transitions linking this new
locality to the graph.
Given a region automaton RA(A)= (L, l0, TR) over ∑, the following algorithm is used for grouping
localities according to the equivalence relation defined above.
Here after, the following notations are considered:
• Π is a partition of L.
• Π0 the initial partition; it is composed by singletons (elements of L). The function frag that
fragments classes P in subclasses formed by singletons.
(10)
(11)
• Function Φ checks if a class Q can be grouped with the class P.
(12)
• The function (13)
• The case of terminal locations is implicitly considered (14)
>
∪
∪
∪
=
=
⊕
=
⊕
=
1
...
2
1
r
1
)
k
(r
)
,..
2
,
1
(r
k
if
k
r
r
k
if
r
k
k
r
r
r
)
( ) { }
Σ
∈
α
→
=
δ α
−
α and
P
Q
,
Q
P
1
( ) { }
Σ
∈
→
= α
δ α
α and
Q
P
Q
P ,
( ) ( ) ( ) ( )
( )
=
∧
−
=
−
∈
Φ
grouped
are
Q
P,
then
'
'
1
1
if
Classes
nd
'
each
for
, Q
P
Q
P
α
P,Q
a
Σ
α,α
Q
P α
δ
α
δ
α
δ
δ
q
p
q
p
k r
r
s
s
s
k
q
p ⊕
=
=
=
= k
r
and
where
)
,
(
Reg
)
( ) ( ) φ
=
δ
=
δ α
α Q
P
7. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
21
6.1 Algorithm
About algorithm, K is a set of grouped localities at each step; at the end Π contains localities of
the aggregated regions automaton; the termination property of the algorithm is ensured by the
finite number of regions in the initial graph. To implement this algorithm we only need an
efficient representation of regions and perform simple operations such as summation over
regions.
( )
{ }
( )
X
of
elements
the
all
marking
until
K
frag(K)
/
Χ
:
Χ
:
l
,
K
Reg
:
K
then
l
,
l
if
in
l
for
l
K
it
mark
and
from
l
choose
repeat
,
0
partition,
initial
0
ik
ij
ik
ij
∪
=
∪
Π
=
Π
=
Φ
Χ
←
Χ
=
Π
Π
=
Χ
=
Π
K
ik
ij
φ
Example 1: The example (Figure 2. and Figure 3.a) present a timed automaton A and the
associated region graph.
Figure 2. Timed automata A.
(a) (b)
Figure 3 (a) Region graph and (b) Aggregated regions graph associated to A.
Figure 3.b, shows the region graph after applying the regions aggregation algorithm.
S0 S1
S2
a,x :=0
y≥1
b,y :=0
x≥1
c
x=1
S0
x=y=0
S2
x≥1,y=0
S2
x=1,y=1
S1
x=0,y≥1
a
b
c
S0
x=y=0
S1
x=0,y=1
S2
x=1,y=0
S2
x>1,y=0
S2
x=1,y=1
S1
x=0,y>1
a
a
b
b
b
b
c
8. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
22
6.2 Equivalence and Validation of Systems
In this subsection we show that the behavior of a timed automaton is a homomorphic image of the
behavior of its aggregated regions automaton. With this result we claim that the validation
operations, particularly the test, generated from the aggregated regions automaton, is sufficient
for assessing an implementation of the timed automaton.
A homomorphism between two sets is a mapping of the elements of one set to the other such that
their respective binary operations are preserved: ( ) ( )
∗
→ ,
,
: B
A
H o . Such that H(x) is an element of
B and for any pair x1, x2 in A, ( ) ( ) ( )
2
1
2
1 x
H
x
H
x
x
H ∗
=
o . (15)
In fact, the proposed algorithm constructs an homomorphism H from ARA(A) to A, mapping the
states of ARA(A) to the states of A while preserving the transition relations over the same actions.
To detail this we define a projection over the set of actions on transitions as:
( ) ( ) '
)
'
,
,
(
'
,
,
,
,
,
'
: τ
γ
τ =
=
∏
=
∏
→
∏ ∑
∑
∑ s
a
s
s
a
g
s
T
T A
A (16)
( ) A
A
AR
H A →
: ,has the following properties:
For all ( ) ( ) 0
0
such that
, s
l
H
S
s
l
H
L
l A
i
A
ij
A
A
ij =
∈
=
∈ (17)
And for all transitions: ( ) ( ) ( ) ( )
( ) ( )
T
l
H
a
l
H
H
l
a
l
T A
kt
A
ij
A
kt
A
ij
AR ∑
∏
∈
=
=
∈ ,
,
,
,
,
, λ
λ
λ (18)
H maps the action of λ to the action of τ in T. The mapping H can be extended in the same way to
map computational paths. A computational path in an aggregated regions automaton corresponds
to sequence of transitions starting from the initial locality of the automaton. That is, H can be
extended to map computations. ( )
A
Exec is a set of all computation of timed automaton A.
( ) ( )
A
Exec
A
AR
Exec
H A →
+
)
(
: (19)
( ) ( ) ( ) ( ) ( )....
....
.....
..... 2
1
0
2
1
0 J
J H
H
H
H
H λ
λ
λ
λ
λ
λ
λ
λ =
+
(20)
These results are summarized as follows: For every computational path in the aggregated regions
automaton ARA(A) there is a computational path in the timed automaton A. The behaviour of A is
a homomorphic image of the behaviour of it’s aggregated regions automaton ARA(A).
Since the localities of the Aggregated regions automaton ARA(A) include clock regions (inherent
from region automaton and more), which are the equivalence classes of regrouped clock
valuations, the timed behavior of A is simulated by the Aggregated regions automaton. Hence, we
claim that the validation methods based on region automata and digitization of their state spaces
are renewed by aggregation regions automata and optimized in the above sense.
Example 2: By changing clocks constraints in the previous example, the regions automaton is
now composed by 7 regions (Figure 4.) The aggregated graph has 4 regions (Figure 5.).
9. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
23
Figure 4. Timed automaton B and the associated region graph.
Figure 5. Aggregated region graph ARA(B).
7. IMPLEMENTATION
In this part we present an experimentation of our approach applied to particular kind of timed
automata model named Durational Actions Timed Automata DATA*. The DATA* model
[21][6][22] is a sub class of timed automata which takes into account the duration of actions. It’s
based on an intuitive idea: temporal and structural non-atomicity of actions. The example below
presents the durational actions automaton model:
Figure 6. DATA* (a).
We present also, an approach to transform DATA* model into aggregate regions automata using
graph transformation [16].
The graph transformation is a process that converts a model to another model. This task requires a
set of rules that define how the source model has to be analyzed and transformed into other
elements of the target model. Graph Grammars are used for model transformation [5][10]. They
are composed of production rules; each having graphs in their left and right hand sides (LHS and
RHS) (Figure 7). AToM3 [12] is a graph transformation tool among others. In this paper we use
it.
S0 S1
S2
a,y :=0
x≤1
b,x :=0
1≤y≤2
c
x=1
b
S0
x=y=0
S1
x=1,y=0
S2
x=0,1<y<2
S2
x=0, y=1
S2
x=1,y=1
S1
y=0,0<x<1
a
a
b
b
b
c
S2
x=0,y=2
b
b
S0
x=y=0
S2
x=0,1≤y≤2
S2
x=1,y=1
S1
y=0,x≤1
a
b
c
S0 S1 S2
{x 2
,y
{y 10}
10. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
24
Figure 7. Example of grammar rule in AToM3 (LHS and RHS).
Example3: To illustrate our approach we propose the example of the ticket reservation system
“TRS”. This example supposes that to buy a ticket, we generally pass by two counters. The first
counter R is for making a reservation and the second counter C is for paying and taking the ticket.
This agency has one waiting room, three counters of type R and two of type C. On arrival, the
client goes to the waiting room, when a counter of type R is free, he can make a reservation. Once
the operation is complete, he waits until a counter C becomes free for paying and taking the
ticket.
Figure 8. presents a DATA* of TRS for two clients with the graph editor dotty. The mapping of
this DATA* with the graph editor dotty to the equivalent DATA* model in AToM3 syntax
(Figure 9.) is performed using python program. We have applied our tool on the DATA* model
and obtained automatically the aggregate region automaton of Figure 10. The result is saved in
the text file of Figure 11.
Figure 8. DATA* of TRS with the graph editor dotty.
Figure 9. DATA* of TRS with AToM3.
11. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
25
Figure 10. Aggregate region automaton.
Figure 11. A textual aggregate region automaton.
8. CONCLUSION AND OUTLOOK
In this paper we proposed an algorithm for reducing region automaton. For this purpose we
defined an equivalence relation among the regions. The proposed aggregation relation preserves
language recognized by the original automaton. As perspectives it seems interesting to develop a
theory of model-checking to verify properties specified in the TCTL logic on aggregated regions
graph. An alternative to the proposed algorithm can be to aggregate localities on the fly, which
consists for building such graph without constructing the full region graph (i.e. at the moment of
generation of R.G associated to the automaton). It is possible because the algorithm requires only
three levels of the initial regions graph. Finally this work can be applied in the test by a way of
partial determinization of the automaton. This is in the same direction of recent promising work
[24][4].
For illustration, we propose a method for generating an aggregated regions automaton from a
Durational actions timed automata by the graph transformation approach and using the
environment AToM3 in order to provide a finite abstraction of DATA* structures with a high
number of states.
Firstly, we have proposed a program written in python language that transforms a DATA*
structure, presented as a dotty file, to a DATA* structure written in the form of a python file
respecting the syntax of AToM3. The meta-modeling tool AToM3 is used for this purpose. We
have illustrated our approach through an example. In future work, we plan to implement our
approach with other tools as AGG in order to compare performances. We plan also to Study the
complexity of this transformation and its use in system testing.
12. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.4, July 2012
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Authors
Ilham Kitouni obtained her BEng degree from University of Mentouri Constantine, Algeria, in 1992, after
15 years in different Algerian company as head of department of Computer Sciences, she recovers CFSC
research group of MISC laboratory, Mentouri University of Constantine, Algeria. From October 2009, she
prepares a PhD thesis. Her research domain is formal models for real-time systems specification and
validation.
Hiba Hachichi received her master’s degree in computing sciences from University of Mentouri
Constantine, Algeria in 2009. Currently, she is a PhD student at CFSC research group of MISC laboratory,
Mentouri University of Constantine, Algeria. Her research interests are graph transformation and formal
methods for verifying and testing real time systems.
Kenza Bouaroudj received her master’s degree in computing sciences from University of Mentouri
Constantine, Algeria in 2010. Currently, she is a PhD student at CFSC research group of MISC laboratory,
Mentouri University of Constantine, Algeria. Her research interests are system validation and testing real-
time stochastic systems.
Djamel-eddine Saidouni received his PHD degree in theoretical computer science from the university Paul
Sabatier of Toulouse, France in 1996. Actually he is a professor at the department of computer science,
Mentouri University of Constantine, Algeria. Also, he is the head of the CFSC research group of MISC
laboratory. His main research domain interests formal models for specifying and verifying critical systems,
real time systems, true concurrency models and state space explosion problem.