ABSTRACT: Nowadays people and their electronic devices access wireless internet. But, clogged airwaves are going to make it increasingly difficult to latch onto a reliable signal. So, Radio waves are just one part of the spectrum that can carry our data. We can use “Data through Illumination”. In this process, the data is sent through an LED source that varies in intensity faster than the human eye could follow. The future can be envisioned where the data for laptops, smart phones and all other smart applications is transmitted through the light in our living room. And security would be a snap—if you can’t see the light, you can’t access the data.
Today’s majority of data technique uses Radio Spectrum. But the major drawback of data
technique using radio spectrum is that it is very congested and the demand for wireless data
double each year. Every one, it seems want to use wireless data but the capacity is drying up.
Light –Fidelity is the transmission of data through illumination .It comprises of sending data
through a Light Emitting Diode which varies in intensity faster than human eye can follow .It
uses the fact that light travels at a such a high speed which is faster than human eye to catch.
Therefore when we vary the intensity of light emitting source it become impossible for the
humans to catch that sensation. It leads to very high speed data transmission, which is for
superior to current technologies.
Li-Fi stand for ―light fidelity‖, it is a wireless optical networking technology that uses light emitting diodes (LEDs) for data transmission. Li-Fi is different from Wi-Fi that transmits data by using the spectrum of visible light.
Today’s majority of data technique uses Radio Spectrum. But the major drawback of data
technique using radio spectrum is that it is very congested and the demand for wireless data
double each year. Every one, it seems want to use wireless data but the capacity is drying up.
Light –Fidelity is the transmission of data through illumination .It comprises of sending data
through a Light Emitting Diode which varies in intensity faster than human eye can follow .It
uses the fact that light travels at a such a high speed which is faster than human eye to catch.
Therefore when we vary the intensity of light emitting source it become impossible for the
humans to catch that sensation. It leads to very high speed data transmission, which is for
superior to current technologies.
Li-Fi stand for ―light fidelity‖, it is a wireless optical networking technology that uses light emitting diodes (LEDs) for data transmission. Li-Fi is different from Wi-Fi that transmits data by using the spectrum of visible light.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
W
hether you’re using wireless internet in a coffee shop,stealing it from the guy next door, or competing for bandwidth at a conference, you have probably gotten frustrated at the slow speeds you face when more than one device is tapped into the network. As more and more people and their manydevices access wireless internet, clogged airwaves are going tomake it.
One German physicist, Harald Haas has come up with asolution he calls “data through illumination” –taking the fibberout of fiber optic by sending data through an LED light bulbthat varies in intensity faster than the human eye can follow.It’s the same idea band behind infrared remote controls but farmore powerful.
Haas says his invention, which he calls D-Light,can produce data rates faster than 10 megabits persecond, which is speedier than your average broadbandconnection. He envisions a future where data for laptops,smart phones, and tablets is transmitted through the light in aroom. And security would be snap – if you can’t see the light,you can’t access the data.
Li-Fi is typically implemented using white LED light bulbs at the downlink transmitter. These devices are normally used for illumination only by applying a constant current. However, by fast and subtle variations of the current, the optical output can be made to vary at extremely high speeds. This very property of optical current is used in Li-Fi setup.The operational procedure is very simple-,data from the internet and local network is used to modulate the intensity of the LED light source if any undetectable to the human eye. The photo detector picks up signal, which is converted back into a data stream and sent to the client.
The client can communicate through its own LED output or over the existing network. An overhead lamp fitted with an LED with signal-processing technology streams data embedded in its beam at ultra-high speeds to the photo-detector. A receiver dongle then converts the tiny changes in amplitude into an electrical signal, which is then converted back into a data stream and transmitted to a computer or mobile device.
Light Fidelity (Li-Fi) is a bidirectional, high speed , fully networked wireless communication technology similar to Wi-Fi. Li-Fi was first put forward by Professor Harald Haas,University of Edinburgh, during a TED Talk in 2011. Li-Fi is a form of visible light communication and a subset of optical wireless communications (OWC) and could be a complement to RF communication (Wi-Fi or Cellular network), or even a replacement in contexts of data broadcasting. It is so far measured to be about 100 times faster than some Wi-Fi implementations, reaching speeds of 224 gigabits per second.
The following ppt gives overview about Optical Communication and the underlying principle with the general overview of all the contents for optical communication
With the vast growing gadgets, their usage and their developments led to the advancement in the Wi-Fi which provides a technology so called Li-Fi.Li-Fi is a technology that makes use of LED light which helps in the transmission of data much more faster and flexible than data that can be transmitted through Wi-Fi.Light reaches nearly everywhere so communication can also go along with light freely. Light Fidelity is a branch of optical wireless communication which is an emerging technology. By using visible light as transmission medium, Li-Fi provides wireless indoor communication. The bit rate achieved by Li-Fi cannot be achieved by Wi-Fi.. Dr herald Haas ,the professor of mobile communications at the university of Edinburgh school of engineering ,first time publically displayed the proof of Light Fidelity(Li-Fi) ,a method of Visible Light communication(VLC). Li-Fi is the transfer of data through light by taking fiber out of fiber optics and sending data through LED light.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
W
hether you’re using wireless internet in a coffee shop,stealing it from the guy next door, or competing for bandwidth at a conference, you have probably gotten frustrated at the slow speeds you face when more than one device is tapped into the network. As more and more people and their manydevices access wireless internet, clogged airwaves are going tomake it.
One German physicist, Harald Haas has come up with asolution he calls “data through illumination” –taking the fibberout of fiber optic by sending data through an LED light bulbthat varies in intensity faster than the human eye can follow.It’s the same idea band behind infrared remote controls but farmore powerful.
Haas says his invention, which he calls D-Light,can produce data rates faster than 10 megabits persecond, which is speedier than your average broadbandconnection. He envisions a future where data for laptops,smart phones, and tablets is transmitted through the light in aroom. And security would be snap – if you can’t see the light,you can’t access the data.
Li-Fi is typically implemented using white LED light bulbs at the downlink transmitter. These devices are normally used for illumination only by applying a constant current. However, by fast and subtle variations of the current, the optical output can be made to vary at extremely high speeds. This very property of optical current is used in Li-Fi setup.The operational procedure is very simple-,data from the internet and local network is used to modulate the intensity of the LED light source if any undetectable to the human eye. The photo detector picks up signal, which is converted back into a data stream and sent to the client.
The client can communicate through its own LED output or over the existing network. An overhead lamp fitted with an LED with signal-processing technology streams data embedded in its beam at ultra-high speeds to the photo-detector. A receiver dongle then converts the tiny changes in amplitude into an electrical signal, which is then converted back into a data stream and transmitted to a computer or mobile device.
Light Fidelity (Li-Fi) is a bidirectional, high speed , fully networked wireless communication technology similar to Wi-Fi. Li-Fi was first put forward by Professor Harald Haas,University of Edinburgh, during a TED Talk in 2011. Li-Fi is a form of visible light communication and a subset of optical wireless communications (OWC) and could be a complement to RF communication (Wi-Fi or Cellular network), or even a replacement in contexts of data broadcasting. It is so far measured to be about 100 times faster than some Wi-Fi implementations, reaching speeds of 224 gigabits per second.
The following ppt gives overview about Optical Communication and the underlying principle with the general overview of all the contents for optical communication
With the vast growing gadgets, their usage and their developments led to the advancement in the Wi-Fi which provides a technology so called Li-Fi.Li-Fi is a technology that makes use of LED light which helps in the transmission of data much more faster and flexible than data that can be transmitted through Wi-Fi.Light reaches nearly everywhere so communication can also go along with light freely. Light Fidelity is a branch of optical wireless communication which is an emerging technology. By using visible light as transmission medium, Li-Fi provides wireless indoor communication. The bit rate achieved by Li-Fi cannot be achieved by Wi-Fi.. Dr herald Haas ,the professor of mobile communications at the university of Edinburgh school of engineering ,first time publically displayed the proof of Light Fidelity(Li-Fi) ,a method of Visible Light communication(VLC). Li-Fi is the transfer of data through light by taking fiber out of fiber optics and sending data through LED light.
Li-Fi stands
for Light-Fidelity is transmission of data through
illumination taking the fibber out of fiber optic by
sending data through an LED light bulb
Light–Fidelity (Li-Fi) is a technology that uses the Light Emitting Diodes (LEDs) to transmit wireless data instead of radio waves.
This is going to be the future of wireless data transmission.
Whether you’re using wireless internet in a coffee shop, stealing it from the guy next door, or competing for
bandwidth at a conference, you’ve probably gotten frustrated at the slow speeds you face when more than one device is
tapped into the network. As more and more people and their many devices access wireless internet, clogged airwaves
are going to make it increasingly difficult to latch onto a reliable signal. But radio waves are just one part of the
spectrum that can carry our data. What if we could use other waves to surf the internet? One German physicist,DR.
Harald Haas, has come up with a solution he calls “Data Through Illumination”—taking the fiber out of fiber optics by
sending data through an LED light bulb that varies in intensity faster than the human eye can follow. It’s the same idea
behind infrared remote controls, but far more powerful. Haas says his invention, which he calls D-Light, can produce
data rates faster than 10 megabits per second, which is speedier than your average broadband connection. He envisions a
future where data for laptops, smartphones, and tablets is transmitted through the light in a room. And security would be
a snap—if you can’t see the light, you can’t access the data. Li-Fi is a VLC, visible light communication, technology
developed by a team of scientists
Modeling And Simulation Swash Plate Pump Response Characteristics in Load Sen...IJMERJOURNAL
ABSTRACT: Fluid Power is widely employed in applications required high loads such as tractors, cranes, and airplanes. In load sensing hydraulic systems, loads are controlled by adjusting a pump-valve arrangement. In this paper, the swash plate pump hydraulic characteristics will be determined, the pump and its fluid gains will be derived to obtain the pump overall transfer function. Firstly, the swash plate pump mechanism is analyzed and its dynamic model is constructed; the pump pressure and flow rate are plotted and the possible improvement is introduced. The load sensing unit parameters such as orifice width, orifice area, maximum passage area, and piston area at X and Y will be examined to identify their influence on the pump characteristics; and the optimum parameters will be introduced. All results are developed and simulated numerically.
Generation of Electricity Through A Non-Municipal Solid Waste Heat From An In...IJMERJOURNAL
ABSTRACT: Energy production, waste disposal, and pollution minimization are key problems that must be addressed for sustainable cities of the environment. Waste management has become a major concern worldwide, and incineration is now being used increasingly to treat waste that cannot be recycled economically. The total heat content of non- municipal waste varies from countries to countries. The tonnage of generation in Nigeria is expected to soar over the next few years and the exploitation of this renewable energy locked up in urban solid municipal waste into grid energy can be taken advantage off.The heat generated from this incinerated plant can be used to generate electricity which will reduce overdependence on fossil fuel and the use of generator which in turn reduces pollution disposal of this waste is incinerated plant for the production of electricity. Hence, this paper intends to review the nonmunicipal waste potential in Nigeria, evaluate its environment and economic cost, and energy content of municipal solid waste deposits in Nigeria.
A New Two-Dimensional Analytical Model of Small Geometry GaAs MESFETIJMERJOURNAL
ABSTRACT : In this paper, a simple and exact analytical model for Small Geometry GaAs MESFET is developed to determine the potential distribution along the channel of the device. The model is based on the exact solution of two-dimensional Poisson’s equation in the depletion region under the gate. Then the obtained model is used to study the channel potential and threshold voltage of the device. Using the analytical model, the effect of the device parameter and bias conditions on performance of the device is investigated. The obtained results are graphically exhibited and discussed. In order to verification of the analytical results, TCAD device simulator is used and good accordance is observed.
Design a WSN Control System for Filter Backwashing ProcessIJMERJOURNAL
ABSTRACT: Day by day, there is a higher rate of need for accurate automation system to be used in industries and environment monitoring and control. In water treatment plants during the filtration phase, there is a process called backwashing, which particles suspended in the filter basin are removed. in this process the water are forcedly pumped through the filter in upward direction at enough speed to expand the filter media. Therefore, various types of valves used, which are opened and closed in a time sequencing manner. The paper proposed an automation control system for the backwashing process to be initiated and completed automatically using PLC, level sensors and valves installed inside the filter basin. Practically, a control system has been applied which all valves are opened and closed according to wireless signals coming from PLCs on its suitable time. In summary, the control in the process demonstrated that the proposed system is efficient, effective, and able to be reliable. Besides, the results increase the productivity at a low-cost mode.
Application of Customer Relationship Management (Crm) Dimensions: A Critical ...IJMERJOURNAL
ABSTRACT”: Customer relationship management is crucial due to the competitive environment. For this reason, it has become a widely implemented strategy across the hotel industry in retaining customers and maintaining good relationships with them. It also promotes customer satisfaction and loyalty which lead to the achievement of competitive business performance. However, due to the ever-increasing competition and the continuous changing customers’ needs in the hotel industry, the ability to achieve customer satisfaction is becoming a major challenge. Using 40 respondents from 20 hotels, this paper, therefore, explores the managers’ perspective into how the application of CRM dimensions impact on the performance of hotels and also examines the relationships between them since studies evaluating their relationships are limited. It studies CRM from the hotels’ perceptive as Guest Services Managers and Marketing Managers were the respondents. This study employed an exploratory research design and quantitative technique. The survey was conducted in New Delhi and simple random sampling was the sampling technique used to select respondents. With the study’s objectives in mind, the developed research hypotheses constructed were tested using multiple regression analysis as the statistical tool. Through the results, it has been revealed that CRM dimensions are positively related to the performance of hotels. Finally, CRM dimensions are highly recommended as a competitive strategic tool to enhance competitiveness.
Comparisons of Shallow Foundations in Different Soil ConditionIJMERJOURNAL
ABSTRACT: Soil is considered by the engineer as a complex material produced by weathering of the solid rock. Footings are structural elements that transmit column or wall loads to the underlying soil below the structure. Footings are designed to transmit these loads to the soil without exceeding its safe bearing capacity. Each building demands the need to solve a problem of foundation on different types of soil. The main aim of this project is to design the appropriate foundation as per size and shape on cohesive, non-cohesive and rocky soil. In this paper different foundation are studied for a middle side and corner column of a building with different bearing capacities. Based on the study and judicial judgment the type of foundation is decided as per depth, quantity of steel and quantity of concrete and try to find which shape of the foundation is more stable, economical and ways to reduce the ease of construction of the building
Place of Power Sector in Public-Private Partnership: A Veritable Tool to Prom...IJMERJOURNAL
ABSTRACT: Public Private Partnership involves private sector engagement in infrastructural development. Though in the past, the country infrastructure had been experiencing a decline in the system, this is because, government had been the sole contributor to infrastructural finance and had often taken responsibility for implementation, operations and maintenance as well. This decline in the system is caused by escalating population growth depending on available infrastructure, decaying of existing power infrastructure, political instability and corruption in the system. The ongoing reform is about bringing the system to a lime light. Hence, Public Private Partnership participation in the infrastructural development in Nigeria, will create favorable environment for an investors, provide job opportunities, long time policy, decision making and efficient use of the available resources. This paper therefore dwells on overview of the public private partnership with regards to energy and other infrastructural development of Nigeria. Challenges of the partnership and possible solutions towards subduing the problems are proffered.
Study of Part Feeding System for Optimization in Fms & Force Analysis Using M...IJMERJOURNAL
ABSTRACT: This paper describes the development of a flexible and vibratory bowl feeding system which is suitable for use in a flexible manufacturing system. The vibratory bowl feeder for automatic assembly, presents a geometric model of the feeder, and develops force analysis, leading to dynamical modeling of the vibratory feeder. Based on the leaf-spring modeling of the three legs of the symmetrically arranged bowl of the feeder, and equating the vibratory feeder to a three-legged parallel mechanism, the paper reveals the geometric property of the feeder. The effects of the leaf-spring legs are transformed to forces and moments acting on the base and bowl of the feeder. Resultant forces are obtained based upon the coordinate transformation, and the moment analysis is produced based upon the orthogonality of the orientation matrix. This reveals the characteristics of the feeder, that the resultant force is along the z-axis and the resultant moment is about the z direction and further generates the closed-form motion equation.
Investigating The Performance of A Steam Power PlantIJMERJOURNAL
ABSTRACT: The performance analysis of Shobra El-Khima power plant in Cairo, Egypt is presented based on energy and exergy analysis to determine the causes , the sites with high exergy destruction , losses and the possibilities of improving the plant performance. The performance of the plant was evaluated at different loads (Full, 75% and, 50 %). The calculated thermal efficiency based on the heat added to the steam was found to be 41.9 %, 41.7 %, 43.9% , while the exergetic efficiency of the power cycle was found to be 44.8%, 45.5% and 48.8% at max, 75% and, 50 % load respectively. The condenser was found to have the largest energy losses where (54.3%, 55.1% and 56.3% at max, 75% and, 50 % load respectively) of the added energy to the steam is lost to the environment. The maximum exergy destruction was found to be in the turbine where the percentage of the exergy destruction was found to be (42%, 59% and 46.1% at max, 75% and, 50 % load respectively). The pump was found to have the minimum exergy destruction. It was also found that the exergy destruction in feed water heaters and in the condenser together represents the maximum exergy destruction in the plant (about 52%). This means that the irreversibilities in the heat transfer devices in the plant have a significant role on the exergy destruction. So, it is thought that the improvement in the power plant will be limited due to the heat transfer devices.
Study of Time Reduction in Manufacturing of Screws Used in Twin Screw PumpIJMERJOURNAL
ABSTRACT: This paper gives the characteristics of Time reduction in manufacturing of screws for Twin screw pumps. Screws are playing a vital role in the performance of pumps, because pumps give the fluids transfer rate with the help of screws. There is a gap in screws which shows its positiveness. This indicates that we are studying about positive displacements pumps. Positive displacements pumps having no point of contact between screws, because of that there will be no any friction formation. Automation is best for development of product to reduce time in manufacturing of any product. In this paper we also tried to explain this feature of Automation to help reduction of time to manufacture of product to increase productivity.
Mitigation of Voltage Imbalance in A Two Feeder Distribution System Using IupqcIJMERJOURNAL
ABSTRACT: Proliferation of electronic equipment in commercial and industrial processes has resulted in increasingly sensitive electrical loads to be fed from power distribution system which introduce contamination to voltage and current waveforms at the point of common coupling of industrial loads. The unified power quality conditioner (UPQC) is connected between two different feeders (lines), hence this method of connection of the UPQC is called as Interline UPQC (IUPQC).This paper proposes a new connection for a UPQC to improve the power quality of two feeders in a distribution system. Interline Unified Power Quality Conditioner (IUPQC), specifically aims at the integration of series VSC and Shunt VSC to provide high quality power supply by means of voltage sag/swell compensation, harmonic elimination in a power distribution network, so that improved power quality can be made available at the point of common coupling. The structure, control and capability of the IUPQC are discussed in this paper. The efficiency of the proposed configuration has been verified through simulation using MATLAB/ SIMULINK.
Adsorption of Methylene Blue From Aqueous Solution with Vermicompost Produced...IJMERJOURNAL
ABSTRACT: The removal of Methylene blue as a synthetic dye from aquatic system was investigated by using vermicompost. The dye concentration, contact time and pH of the solution carried out in the adsorption studies. Batch adsorption experimental data were suitable for the Langmuir isotherm and a very good fit to the second order kinetic model (pH=10). The maximum adsorption capacity calculated 256.66 mg g-1 . Vermicompost and the dye loaded vermicompost were characterized by SEM and FTIR. It was found that the vermicompost is stable without losing their activity.
Analytical Solutions of simultaneous Linear Differential Equations in Chemica...IJMERJOURNAL
ABSTRACT: Analytical method for solving homogeneous linear differential equations in chemical kinetics and pharmacokinetics using homotopy perturbation method has been proposed. The mathematical model that depicts the pharmacokinetics is solved. Herein, we report the closed form of an analytical expression for concentrations species for all values of kinetic parameters. These results are compared with numerical results and are found to be in satisfactory agreement. The obtained results are valid for the whole solution domain.
Experimental Investigation of the Effect of Injection of OxyHydrogen Gas on t...IJMERJOURNAL
ABSTRAC: Oxy-Hydrogen gas, H2O2, is a mixture of hydrogen and oxygen produced by water electrolysis. In this work, an experimental exploration was carried out in order to study the effect of the addition of oxy-hydrogen gas into inlet air manifold on speed performance characteristics of a diesel engine at different operating conditions. The experimental work was performed on a test rig comprising a four stroke 5.67 liters water-cooled diesel engine and a Heenan hydraulic dynamometer. Instrumentation included devices for measuring engine speed, load, fuel consumption and inlet air flow rate. The measurements were conducted at 1000, 1500, 2000 and 2500 rpm. At each speed, the engine load was adjusted to 20%, 40% and 80% from the engine full load which corresponds to engine brake mean effective pressures of 1.55, 3.11, and 6.22 bar, respectively, for Oxy-hydrogen generator supplied Currents of 26A and electrolyte concentration of 25 %. The fuel saving percentage and so the brake thermal efficiency for the H2O2 enriched CI engine is more evidently seen at low loads and high-speed conditions. the volumetric efficiency drop was about 5 % at small speeds and reaches to about 2% at higher engine speed.
Hybrid Methods of Some Evolutionary Computations AndKalman Filter on Option P...IJMERJOURNAL
ABSTRACT: The search for a better option price continues within the financial institution. In pricing a put option, holders of the underlying stock always want to make the best decision by maximizing profit. We present an optimal hybrid model among the following combinations: Kalman Filter-Genetic Programming(KF-GP), Kalman Filter-Evolutionary Strategy(KF-ES) and Evolutionary Strategy -Genetic Programming(ES- GP). Our results indicate that the hybrid method involving Kalman Filter-Evolutionary Strategy(KF-ES) is the best model for any investor. Sensitivity analysis was conducted on the model parameters to ascertain the rigidity of the model.
An Efficient Methodology To Develop A Secured E-Learning System Using Cloud C...IJMERJOURNAL
ABSTRACT: Now-a-days, each and every action involved in our life becomes computerized in order to reduce the time, complexity and manual power. The education systems are also being computerized, to train the students in a much efficient way. This system is termed as E-Learning. E-Learning is an Internet-based learning process, in which the Internet technology is used to design, implement, manage and extend learning, which will improve the efficiency of learning. Learning, Teaching and Training are intensely connected components, which are all included in the development of E-Learning system. Cloud Computing provides an efficient platform to support the E-Learning systems, as it can be dramatically changes over time .In this paper, an overview on the new emerging E-Learning system , utilization of the SAAS (Software as a Service) and the methodology to test the efficiency of the person in a secured way are described.
Nigerian Economy and the Impact of Alternative Energy.IJMERJOURNAL
ABSTRACT: Nigeria is endowed with natural resources which are aim at developing the country.The need for alternative energy resources to drive the nation economy cannot be over-emphasized. The incessant power failure has grossly affected the economy, seriously slowing down development in rural and sub-rural settlement. A robust solution must be found to end the crises. Alternative energy source has the potential of solving power problem in Nigeria as well as providing safer and cleaner environment than the fossil fuel. This paper also examines the socio–economic benefits of the alternative energy (solar, wind, biomass, hydro and geothermal) to the nation economy and the utilization of the resources to meet human needs and the generation yet unborn and to provide sustainable development, thereby improve the standard of living and mitigating climate change.
ABSTRACT: Many writers describe empowerment as a process as opposed to a condition or state of being which is being a key feature of empowerment emphasized by many researchers. As a process empowerment becomes difficult to be measured by standard tools available to social scientists. As case study helps in bringing us to understand a complex issue or object and can extend experience or add strength to what is already known through previous research. Case studies also emphasized on detailed contextual analysis of a limited number of events or conditions and their relationships. Researcher had made use of this qualitative research method to examine contemporary real-life situations.
Validation of Maintenance Policy of Steel Plant Machine Shop By Analytic Hier...IJMERJOURNAL
ABSTRACT: In this paper the maintenance activities of the Machine shop of Steel plant have been considered. As maintenance is a routine activity to keep a machine at its normal operating condition so that it can deliver its expected performance without causing any loose of time on account of accidental damage or breakdown and maintenance is a recurring activity. So for reduction of maintenance cost and safety of the operator as well as the residents of nearby area it is better to decide which machines should go for which type of maintenance. For this decision AHP is used and the Expert choice software is used for that calculations and this paper is for the validation of results.
The Comprehensive Computation Model of Gas Permeability Based on Fuzzy Comple...IJMERJOURNAL
ABSTRACT: In this paper, in order to reveal the gas migration law of loaded coal under multi-factor coupling, the researches on gas permeability were carried out under different influencing factors, namely effective stress, gas pressure, confining pressure and moisture content, with the self-developed experimental platform of gas permeability. Meanwhile, the function relationship of each influencing factor and permeability was established by use of the mathematical least squares principle. In this paper, the comprehensive expression of gas permeability was established, which is based on fuzzy complementary judgment matrix. And the comprehensive expression was drawn from the experimental conclusions of the loaded coal under multi-factor coupling.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
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.
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
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
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/
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
OPEN ACCESS Journal
Of Modern Engineering Research (IJMER)
| IJMER | ISSN: 2249–6645 www.ijmer.com | Vol. 7 | Iss. 7 | July. 2017 | 1 |
li-fi: the future of wireless communication
K.Krishna Chaitanya
Electronics and Communication Engineering R.M.D Engineering College
R.S.M Nagar,Kavaraipettai ,Chennai.
I. INTRODUCTION
Li-Fi is a VLC technology. In simple terms, Li-Fi can be visualized as a light based
Wi-Fi, in which light waves are used instead of the radio waves. The system will use a
transceiver, fitted with LED lamps that can light a room as well as transmit and receive
information. It is possible to encode data in the light by varying the rate at which the LEDs
flicker on and off to give different strings of 1s and 0s. The LED intensity is modulated so
rapidly that human eyes cannot notice, so the output appears constant.
Theoretically, Li-Fi could transmit data at a rate of 3 GB/sec but in practical
conditions, the data rate is 500 MB/sec. So this means that a 1080p HD video can be
downloaded in just ten seconds.
The working
Li-fi is implemented using an array of LED bulbs at the transceiver. These devices are
illuminated by applying a constant current. Now, when the intensity of the LED is varied at a
very fast rate, such that it is unseen by the human eyes, the transmission of the data occurs.
To get further grasp of Li-Fi consider an IR remote. It sends a data stream of bits at the rate
of 10,000 – 20,000 bps.
Now replace the IR LED with a large normal LED. Now it is capable of sending thousands of
such streams at a very fast rate.
A. Encoding the data
The data is encoded using a microcontroller and is then fed to the LED. Now when
the LED is ON, a digital 1 is transmitted and when it is OFF a digital 0 is transmitted. The
process is done at a very high speed such that it is invisible to the human eye and the data is
transmitted from the source to destination.
ABSTRACT: Nowadays people and their electronic devices access wireless internet. But, clogged airwaves are
going to make it increasingly difficult to latch onto a reliable signal. So, Radio waves are just one part of the
spectrum that can carry our data.
We can use “Data through Illumination”. In this process, the data is sent through an LED source that varies in
intensity faster than the human eye could follow. The future can be envisioned where the data for laptops, smart
phones and all other smart applications is transmitted through the light in our living room. And security would be a
snap—if you can’t see the light, you can’t access the data.
Keywords: Wireless communication, Light-Fidelity (Li-Fi), Visible Light Communication (VLC), wireless
networking, optical communication.
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Fig.1 Transmission of data using Li-Fi
B. Enhancements to Li-Fi
The Li-Fi can be further enhanced by using an array of LEDs, using red, green and
blue LEDs, altering the frequency of the light with each frequency encoding a different data
channel. This will help to download or stream 1080p HD video content at a rate of 10 GB/sec.
Fig.2 Multiple uses of Li-Fi
Need for Li-Fi
There are certain adverse effects caused by radio communication and hence the need for Li-Fi
arises.
A. Present scenario of wireless communication
The present scenario of wireless communication is as follows,
1.4 million Cellular radio masts have been deployed.
More than 5 million Wi-Fi devices are present.
Nearly 700 TB of data transmission takes place per month.
Wireless communication has become an important utility in our everyday life. Life without
wireless communication is now unthinkable. So, the need arises to improve the wireless
technology and so the concept of Li-Fi has been introduced.
B. Issues with Wi-Fi
There are mainly four issues with the current scenario as explained below,
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1) Capacity
Transmission of wireless data through radio waves is
restricted to a certain range.
These waves are scarce, expensive and so its availability is limited.
2) Efficiency
Most of the energy consumed, is not used to transmit the radio waves, but is used to cool
the base stations.
The efficiency of such a base station is only at about five percent.
3) Health issues
There are potential health issues associated with radio waves. In some cases extensive exposure to these
waves may cause health problems like cancer.
Consequently we have to switch off devices like cell-phones in places like hospitals
4) Security
The radio waves can be intercepted, and somebody can make use of one’s network.
So, it remains as a major concern in wireless communication.
I.
II. THE BEST ALTERNATIVE
As, there are certain drawbacks in radio waves, a study was made in the electromagnetic spectrum and the
results were concluded. The spectrum is shown in the below figure.
Fig.3 The electromagnetic spectrum
From the study of the spectrum, it was found that,
Gamma rays can’t be used as they could be dangerous for health.
X-Rays also have similar health issues.
UV rays is acceptable only in minute intensity, so it also can’t be used.
Infrared can be used only with low power due to eye safety regulations.
And so, the Visible Light spectrum is the most safest and efficient method of transmitting
the data. It is nearly 10,000 times more efficient than the ordinary radio waves. So it has a
very big advantage. Light is inherently safe and can be used in places where radio frequency
communication is often deemed problematic, such as in aircraft cabins or hospitals. So visible
light communication not only has the potential to solve the problem of lack of spectrum space,
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but can also enable novel application. The visible light spectrum is unused, it's not regulated,
and can be used for communication at very high speeds.
III. THE ADVANTAGES OF LI-FI
A. Capacity
The spectrum region of visible light is nearly 10,000 times greater than that of the radio
waves and hence it gives us the option to use more channel to transmit the data.
B. Efficiency
An LED consumes very less power and hence it is more efficient and power saving.
Moreover, LEDs are available at a very cheaper rate and hence they are cost efficient.
C. Safety
Visible light poses no health issues, so it is completely safe to use it anywhere. It can also be
used in aeroplanes, hospitals, and other areas where radio waves cannot be used.
D. Security
As the transmission is very fast and as it takes place in a fraction of second, it is very much
secure than the radio waves and it is very difficult to interpret or eavesdrop the messages.
IV. APPLICATIONS OF LI-FI
The Li-Fi is still in development process but it has a very vast application. Some of them are
as follows,
A.Traffic lights
Traffic lights can be made to communicate with the each other and can also
communicate with each other. Vehicles also can be provided with LED lights so that they can
communicate with each other and prevent accidents by exchanging information.
B. Intrinsically safe environments
Visible lights are much safer than RF and hence it can be used in where RF can’t be used
such as petrochemical plants, airplanes, hospitals, etc.
c. Internet hotspots
Using this technology, internet access can be provided to the public from the light sources
available anywhere. For example, even the street lights can act as internet hotspots.
d. D. On ocean beds
Li-Fi can even work underwater where Wi-Fi fails completely and thereby throwing open
endless opportunities for military or navigation operations.
VII. DISADVANTAGES
The biggest disadvantage is that it needs direct line of sight to transmit data.
There will be interference from sunlight.
Requirement of special kind of LEDs.
Flickering of the light.
VLC is unidirectional.
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You cannot dim the lights.
Lights need to be on, so this is inefficient.
VIII. OVERCOMING THE DISADVANTAGES
After studying carefully about the VLC system and Li-Fi, we have framed certain
ideas and solutions to the disadvantages or restrictions mentioned above. The solutions for
the problems are as follows.
A. Direct line of site
Line of sight is a definite advantage because the signal will be stronger. However, if
you look under the table you can still see despite there being no line of sight from the sun or
from artificial sources. If a VLC receiver can collect photons, it can receive data, albeit at a
lower data rate if light levels are low. Radio technology is similar in that indirect signals have
a lower power and hence the data rate reduces. Visible light can be reflected but generally
does not penetrate materials which can be a security advantage and perhaps a coverage
disadvantage. Radio can suffer multipath interference from non-line of sight reflected signal
cancelling each other by being in anti-phase – leads to signal fading. VLC signal always add
and cannot cancel each other and cause fading which is a significant advantage.
B. Overcoming the interference problem
It is relatively simple to eliminate the vast majority of interference from natural and
artificial sources using optical filters (which avoids receiver saturation). After the photo-
detector further analogue and digital filtering ensure remaining interference is negligible.
C. Overcoming the need for special LEDs
Specialist LEDs with ideal characteristics for VLC would be great. However, solid
state LED lighting is currently being sold based on its performance for illumination purposes
(colour temperature, efficacy, CRI, lifetime, etc). Communications performance is not even a
secondary consideration, so it is wholly unrealistic to expect the lighting industry to factor
this into designs at this stage.
In a practical sense we can achieve excellent results with COTS LED devices, if better
devices are available great, but to implement VLC we can use existing LED devices. When
VLC becomes a significant part of the LED industry then we can start to influence the
specification of these devices.
D. Overcoming flickering problems
We subtly modulate the current supply to the LED devices at relatively high speeds.
We are not harshly switching the LEDs on and off, and we are not modulating at speeds
anywhere near those perceptible to the human eye. Your TV and computer displays do flicker
at just higher than perceptible rates, the same is true of some LED dimming technologies.
VLC does not flicker the lights like this, it will not give you a headache!
E. Overcoming unidirectional issues
VLC can be used for transmission in either direction. The uplink and downlink can be
isolated in a number of ways – wavelength, time, code and also by spatial or optical isolation.
For practical and cost reasons VLC might be implemented for downlink only since this is
where bottlenecks exist with existing technologies, e.g. Wi-Fi may already provide a reliable
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uplink where congestion is less likely and Li-Fi provides a high capacity uncongested
downlink.
F. Overcoming the dimming issues
There are VLC patents pending on methods to dim the LED while maintaining high
data rates until the current is dimmed to about 50%. After that the data rates will begin to
diminish in a very graceful manner. So yes, you can dim the lights and maintain
communications reliably.
G. Overcoming the issues with the LED lights always being ON
To use VLC the lights do need to be on. However in the vast majority of industrial,
commercial and retail environments the lights are on when the area is occupied. Given that
the lights are usually on, VLC transmission power comes free as it is already used for
illumination so this is highly efficient.
In domestic environments we do tend to switch off lights during daylight. Where the
lights would have been off the power required for VLC is not free but the lights only need to
be dimmed up to transmit data. The illumination need not be above ambient levels so will not
be noticed. The power consumed is comparable with the watts/bit for radio transmission and
so on aggregate even in domestic environments there is a significant net saving in power.
IX. CONCLUSION
Li-Fi is certainly not useless, but it has certain inherent limits for the technology. Li-
Fi may not be able to replace conventional radios altogether, but it could turbocharge the
development of wireless television and make it easier to throw a wireless signal across an
entire house. At present, finding the ideal position for a wireless router is something of a
divine art. If the signal could be passed via VLC from Point A to Point B inside a home,
small local routers at both points could create local fields with less chance of overlapping and
interfering with each other. Large scale areas that are saturated with radio signals or that
don’t permit them for security reasons could use Li-Fi as an alternate high-speed wireless
network solution.
REFERENCES
[1] Wikipedia, The principles of Li-Fi technology.
[2] Ultra Parallel Visible Light Communications(UP-VLC)[Online] Available: http://up-vlc.photonics.ac.uk/
[3] (2002) The IEEE website. [Online]. Available: http://www.ieee.org/
[4] The TED website [Online]. Available: http://www.ted.com/
[5] Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specification, IEEE Std. 802.11, 1997.