Electrical Capacitance Tomography (ECT) determines the dielectric permittivity of the interior object depending on the measurements of exterior capacitance. Generally, the electrodes are placed outside the PVC cylinde...Electrical Capacitance Tomography (ECT) determines the dielectric permittivity of the interior object depending on the measurements of exterior capacitance. Generally, the electrodes are placed outside the PVC cylinder where the medium to be imaged is present;but in ECT using inter-electrode capacitance measurements can be achieved by placing inside of the dielectric medium. In the proposed ECT system, the ECT sensor is modeled using ANSYS software and the model is implemented in real ECT system. For each step of measurement, a stable AC signal is applied to a pair of electrodes that form a capacitor. The novel system is to measure the capacitance range variation in picofarad and the corresponding voltage ranges from 1 volt to 4 volts. The switching speed of all combinational electrodes is implemented using embedded system to achieve higher speed performance of AC ECT system which eliminates the drift and stray capacitance error. This is yielding the original image of unknown multiphase medium inside the electrodes using Lab VIEW. This paper investigates several advantages such as improved overall system performance;simple structure, avoids stray capacitance effect, reduces the drift problem and achieves high signal to noise ratio.展开更多
In this paper, a novel 10 Transistor Static Random Access Memory (SRAM) cell is proposed. Read and Write bit lines are decoupled in the proposed cell. Feedback loop-cutting with single bit line write scheme is employe...In this paper, a novel 10 Transistor Static Random Access Memory (SRAM) cell is proposed. Read and Write bit lines are decoupled in the proposed cell. Feedback loop-cutting with single bit line write scheme is employed in the 10 Transistor SRAM cell to reduce active power consumption during the write operation. Read access time and write access time are measured for proposed cell architecture based on Eldo SPICE simulation using TSMC based 90 nm Complementary Metal Oxide Semiconductor (CMOS) technology at various process corners. Leakage current measurements made on hold mode of operation show that proposed cell architecture is having 12.31 nano amperes as compared to 40.63 nano amperes of the standard 6 Transistor cell. 10 Transistor cell also has better performance in terms of leakage power as compared to 6 Transistor cell.展开更多
Secured Two Phase Geographic Greedy Forwarding (SecuTPGF) is a geographic greedy forwarding protocol for transmitting multimedia data stream in Wireless Multimedia Sensor Networks (WMSN) in a secure and reli...Secured Two Phase Geographic Greedy Forwarding (SecuTPGF) is a geographic greedy forwarding protocol for transmitting multimedia data stream in Wireless Multimedia Sensor Networks (WMSN) in a secure and reliable manner. Cryptographic and MAC authentication mechanisms are used to implement security for both node and message authentication. In this paper, a modified version of SecuTPGF, the GSTP routing provides security for both node and message authentication by using MD5 algorithm with a reduced computation power. In SecuTPGF, two different algorithms are used for node and message authentication, and GSTP routing uses “MD5Algorithm” for both node and message authentication. Using MD5 algorithm for node and message authentication, the average number of transmission paths increased and average number of hops used for transmission decreased when compared to the SecuTPGF. By conducting security analysis & evaluation experiments, the effectiveness of GSTP routing algorithm is proved.展开更多
Induction motor is the most sought after motor in the industry for excellent performance characteristics and robustness. Developments in the Power Electronic circuitry have revolutionised the induction motor industry ...Induction motor is the most sought after motor in the industry for excellent performance characteristics and robustness. Developments in the Power Electronic circuitry have revolutionised the induction motor industry leading to the developments in various control strategies and circuits for motor control. Direct Torque Control (DTC) is one of the excellent control strategies preferred by industries for controlling the torque and flux in an induction machine. The main drawback of DTC is the presence of torque ripple which is slightly more than the acceptable limit. There are various parameters that introduce ripples in the electromagnetic torque, one of them being the type of inverter circuit. There are various types of inverter circuits available and the effect of each of them in the production of torque ripple is different. This work is an attempt to identify the influence of various multilevel inverter circuits on the torque ripple level and to propose the best inverter circuit. The influence of multilevel diode clamped inverter and cascaded H bridge inverter circuits on torque ripple minimization, is analysed using simulation studies for identifying the most suitable multilevel inverter circuit which gives minimum torque ripple. The results obtained from the simulation studies are validated by hardware implementation on 0.75 kW induction motor.展开更多
Consumption of the electric power highly depends on the Season under consideration. The various means of power generation methods using renewable resources such as sunlight, wind, rain, tides, and waves are season dep...Consumption of the electric power highly depends on the Season under consideration. The various means of power generation methods using renewable resources such as sunlight, wind, rain, tides, and waves are season dependent. This paves the way for analyzing the demand for electric power based on various Seasons. Many traditional methods are utilized previously for the seasonal based electricity demand forecasting. With the development of the advanced tools, these methods are replaced by efficient forecasting techniques. In this paper, a WEKA time series forecasting is being done for the electric power demand for the three seasons such as summer, winter and rainy seasons. The monthly electric consumption data of domestic category is collected from Tamil Nadu Electricity Board (TNEB). Data collected has been pruned based on the three seasons. The WEKA learning algorithms such as Multilayer Perceptron, Support Vector Machine, Linear Regression, and Gaussian Process are used for implementation. The Mean Absolute Error (MAE) and Direction Accuracy (DA) are calculated for the WEKA learning algorithms and they are compared to find the best learning algorithm. The Support Vector Machine algorithm exhibits low Mean Absolute Error and high Direction Accuracy than other WEKA learning algorithms. Hence, the Support Vector Machine learning algorithm is proven to be the WEKA learning algorithm for seasonal based electricity demand forecasting. The need of the hour is to predict and act in the deficit power. This paper is a prelude for such activity and an eye opener in this field.展开更多
In the field of analog VLSI design, current conveyors have reasonably established their identity as an important circuit design element. In the literature published during the past few years, numerous application have...In the field of analog VLSI design, current conveyors have reasonably established their identity as an important circuit design element. In the literature published during the past few years, numerous application have been reported which are based on a variety of current conveyors. In this paper, an oscillator circuit has been proposed. This oscillator is designed using a single positive type second generation current controlled current conveyor (CCCII+). A CCCII has parasitic input resistance on it’s current input node. This resistance could be exploited to reduce circuit complexities. Thus in this accord, a novel oscillator circuit is proposed which utilizes the parasitic resistance of the CCCII+ along with a few more passive components.展开更多
In this paper, four new first order voltage mode cascadable allpass sections are proposed using single active element and three grounded passive components, ideal for IC implementation. The active element used is a fu...In this paper, four new first order voltage mode cascadable allpass sections are proposed using single active element and three grounded passive components, ideal for IC implementation. The active element used is a fully differential current conveyor. All the proposed circuit possess high input and low output impedance feature which is a desirable feature for voltagemode circuits. Nonideality aspects and parasitic effects are also given. As an application, a multiphase oscillator is designed. The proposed circuits are verified through PSPICE simulation results using TSMC 0.35 µm CMOS parameters.展开更多
Classifying the data into a meaningful group is one of the fundamental ways of understanding and learning the valuable information. High-quality clustering methods are necessary for the valuable and efficient analysis...Classifying the data into a meaningful group is one of the fundamental ways of understanding and learning the valuable information. High-quality clustering methods are necessary for the valuable and efficient analysis of the increasing data. The Firefly Algorithm (FA) is one of the bio-inspired algorithms and it is recently used to solve the clustering problems. In this paper, Hybrid F-Firefly algorithm is developed by combining the Fuzzy C-Means (FCM) with FA to improve the clustering accuracy with global optimum solution. The Hybrid F-Firefly algorithm is developed by incorporating FCM operator at the end of each iteration in FA algorithm. This proposed algorithm is designed to utilize the goodness of existing algorithm and to enhance the original FA algorithm by solving the shortcomings in the FCM algorithm like the trapping in local optima and sensitive to initial seed points. In this research work, the Hybrid F-Firefly algorithm is implemented and experimentally tested for various performance measures under six different benchmark datasets. From the experimental results, it is observed that the Hybrid F-Firefly algorithm significantly improves the intra-cluster distance when compared with the existing algorithms like K-means, FCM and FA algorithm.展开更多
In Dynamic Economic Load Dispatch (DELD), optimization and evolution computation become a major part with the strategy for solving the issues. From various algorithms Differential Evolution (DE) and Particle Swarm Opt...In Dynamic Economic Load Dispatch (DELD), optimization and evolution computation become a major part with the strategy for solving the issues. From various algorithms Differential Evolution (DE) and Particle Swarm Optimization (PSO) algorithms are used to encode in a vector form and in sharing information and both approaches are based on the master-apprentice mechanism for the Dual Evolution Strategy. In order to overcome the challenges like the clustering of PSO, optimization problems and maximum and minimum searching, a new approach is developed with the improvement of searching and efficient process. In this paper, an Enhanced Hybrid Differential Evolution and Particle Swarm Optimization (EHDE-PSO) is proposed with Dynamic Sigmoid Weight using parallel procedures. A hybrid form of the proposed approach combines the optimizing algorithm of Enhanced PSO with the Differential Evolution (DE) for the improvement of computation using parallel process. The implementation and the parallel process are analyzed and discussed to gather relevant data to show the performance enhancement which is better than the existing algorithm.展开更多
The paper focuses on the design and Field Programmable Gate Array (FPGA) implementation of embedded system for time based dual encryption scheme with Delay Compulsion Function (DCF) and also illustrates the applicatio...The paper focuses on the design and Field Programmable Gate Array (FPGA) implementation of embedded system for time based dual encryption scheme with Delay Compulsion Function (DCF) and also illustrates the application of DCF in time based cryptography. Further, the strength of the time based FPGA encryption algorithm with and without using DCF is analyzed using a Nios II processor. This proposed scheme enhances the security of vital data against Brute force attack by incorporating a temporal key distribution where two different keys encrypt the data simultaneously, one being the regular key and the other being the time. The time is included using a dynamically varying number of shifts thereby allowing the system to wait for the duration and this forms the second dimension of the key. Presently, available encryption systems suffer from Brute Force attack in which all the key combinations are tried in order to find the correct key. In such a case, the time taken for breaking the key depends on the speed of the system used for cryptanalysis. The proposed system adds complexity by using dynamically varying sequence of operations, by including the time as a second dimension of the key besides minimizing the possibility of Brute Force attack and increasing the time required for cryptanalysis irrespective of the system capability. As the proposed system needs concurrent execution and real time processing, the system is implemented using Altera Stratix II FPGA and the results are presented.展开更多
The static flow resistivity is a fundamental parameter for measuring and classifying the sound absorption behavior of various types of materials. Several methods have been developed for measuring the static flow resis...The static flow resistivity is a fundamental parameter for measuring and classifying the sound absorption behavior of various types of materials. Several methods have been developed for measuring the static flow resistivity acoustically. Most of these methods cannot be implemented directly in the standard tubes which are widely used for measurements of sound absorption coefficients and impedance as defined in ISO 10534.2. The accuracy of the proposed method and the tube is verified through finite element analysis and the feasibility to determine the static flow resistivity is validated through experiments. It is validated that the accuracy of the proposed method is highly dependent on the position of the acoustic center of the measurement microphones and the accuracy can be enhanced by increasing the back cavity depth and/or decreasing the measurement frequency.展开更多
In this modern era, power generation seems to be a very demanding factor. New models and methods have been proposed to derive from various natural and manmade resources. In such instances, this paper gives a detailed ...In this modern era, power generation seems to be a very demanding factor. New models and methods have been proposed to derive from various natural and manmade resources. In such instances, this paper gives a detailed report on the power generation from Micro Turbines. Micro turbine plays a very important role in electric power generation. Especially they are used in the combined cycle process power plants. The parameters of Rowen’s model 265-MW single shaftheavy duty gas turbines which are used in dynamic studies are estimated in this paper using the operational and performance data. These data are also used to briefly explain the extraction of parameters of the used model. Micro turbine parameters are approximated using simple thermodynamics assumptions. Micro turbine power generation seems to be an uprising and a promising source and an exact design with a perfect model is capable of producing the highest efficiency. Thus this paper is proposed on the aspects of social awareness to elaborate the control design of Micro Turbine Power Generation System. The parameters of micro turbine models are derived and the results of several simulated tests using Matlab/Simulink are presented.展开更多
A new circuit for realization of universal current-mode filter using current Follower Transconductance Amplifiers (CFTAs) is presented. The proposed circuit realizes current-mode low pass, high pass and band pass filt...A new circuit for realization of universal current-mode filter using current Follower Transconductance Amplifiers (CFTAs) is presented. The proposed circuit realizes current-mode low pass, high pass and band pass filter functions simultaneously with a single current source at the input. The band reject and all pass filters can also be obtained from the proposed circuit without any extra hardware. The proposed circuit employs three passive grounded elements and two CFTAs. Linear electronic control of natural frequency ω0 is available in the proposed circuit. The quality factor can be independently adjusted through grounded resistor. The proposed circuit employs two grounded capacitors and a grounded resistor along with two CFTAs. The grounded resistor can be replaced by an OTA based circuit for linear electronic control of quality factor Q0. The circuit exhibits low active and passive sensitivities for ω0 and Q0. Simulation results are obtained using PSPICE software which is in conformity with the theoretical findings.展开更多
Processes of high-frequency (HF) heating are examined and its parameters for the soldering of electronic modules are optimized. The advantages of HF heating are the following: selectivity by skin-effect;high density o...Processes of high-frequency (HF) heating are examined and its parameters for the soldering of electronic modules are optimized. The advantages of HF heating are the following: selectivity by skin-effect;high density of energy;process- ing in any environment, including vacuum or inert gas;high ecological cleanliness, improvement solder flowing by electrodynamics forces increase the quality of soldering connections. Investigation of HF electromagnetic heating has allowed to optimize heating speed in local zones of soldering connections formation and to improve their quality due to joint action of superficial effects and electromagnetic forces.展开更多
This work summarizes the structure and operating features of a high-performance 3-stage dual-delay-path (DDP) voltage-controlled ring oscillator (VCRO) with self-biased delay cells for Phase-Locked Loop (PLL) structur...This work summarizes the structure and operating features of a high-performance 3-stage dual-delay-path (DDP) voltage-controlled ring oscillator (VCRO) with self-biased delay cells for Phase-Locked Loop (PLL) structurebased clock generation and digital system driving. For a voltage supply V<sub>DD</sub> = 1.8 V, the resulting set of performance parameters include power consumption P<sub><sub></sub>DC</sub> = 4.68 mW and phase noise PN@1MHz = -107.8 dBc/Hz. From the trade-off involving P<sub>DC</sub> and PN, a system level high performance is obtained considering a reference figure-of-merit ( FoM = -224 dBc/Hz ). Implemented at schematic level by applying CMOS-based technology (UMC L180), the proposed VCRO was designed at Cadence environment and optimized at MunEDA WiCkeD tool.展开更多
Voltage divider biasing common emitter amplifier is one of the core contents in analog circuit curriculum, and almost all of traditional textbooks apply approximate calculation method to estimate all characteristic pa...Voltage divider biasing common emitter amplifier is one of the core contents in analog circuit curriculum, and almost all of traditional textbooks apply approximate calculation method to estimate all characteristic parameters. In calculating quiescent point, transistor base current is generally ignored to get the approximate base potential and emitter current, then other operating parameters, and AC small signal parameters can be acquired. The main purpose of this paper is to compare traditional and Thevenin equivalent methods and to get the difference of the two methods. A Formula is given to calculate the error of the traditional method. Example calculating reveals that the traditional method can generate an error about 10%, and even severe for small signal amplifier with higher quiescent point.展开更多
In large inter connected power systems, inter-area oscillations are turned to be a severe problem. Hence inter-area oscillations cause severe problems like damage to generators, reduce the power transfer capability of...In large inter connected power systems, inter-area oscillations are turned to be a severe problem. Hence inter-area oscillations cause severe problems like damage to generators, reduce the power transfer capability of transmission lines, increase wear and tear on network components, increase line losses etc. This paper is to maintain the stability of system by damping inter-area oscillations. Implementation of new equipment consists of high power electronics based technologies such as FACTs and proper controller design has become an essential to provide better damping performance than Power System Stabilizer (PSS). With development of Wide Area Measurement System (WAMS), remote signals have become as feedback signals to design Wide Area Damping Controller (WADC) for FACTs devices. In this work, POD is applied to both SVC and SSSC. Simulation studies are carried out in Power System Analysis Toolbox (PSAT) environment to evaluate the effectiveness of the FACTs controller in a large area power system. Results show that extensive analysis of FACTs controller for improving stability of system.展开更多
A new Single-Resistance-Controlled (SRC) sinusoidal oscillator using single Voltage Differencing-Differential Input Buffered Amplifier (VD-DIBA), only four passive components (two capacitors and two resistors), is pre...A new Single-Resistance-Controlled (SRC) sinusoidal oscillator using single Voltage Differencing-Differential Input Buffered Amplifier (VD-DIBA), only four passive components (two capacitors and two resistors), is presented. The proposed structure provides the following advantageous features: 1) independent control of oscillation frequency and condition of oscillation and 2) low active and passive sensitivities. The effects of non-idealities of the VD-DIBA on the proposed oscillator have also been investigated. The proposed SRC sinusoidal oscillator has been checked for robustness using Monte-Carlo simulation. SPICE simulation results have been included using 0.35 μm MIETEC technology to confirm the validity of the proposed SRC sinusoidal oscillator.展开更多
This paper introduces a novel single-phase asymmetrical multilevel inverter suitable for hybrid renewable energy sources. The proposed inverter consists of two isolated DC sources and six power semiconductor controlle...This paper introduces a novel single-phase asymmetrical multilevel inverter suitable for hybrid renewable energy sources. The proposed inverter consists of two isolated DC sources and six power semiconductor controlled switches. The suggested inverter is capable of generating seven-level output when the input DC voltage is taken in the ratio of 1:2. The higher magnitude DC source is fed from Photo Voltaic (PV) panels, whereas the lower magnitude DC source is fed from Wind Turbine (WT) driven Permanent Magnet DC (PMDC) generator. Both the renewable energy sources are connected to the inverter via two DC-DC boost converters connected in cascade (i.e. one for maximum power point tracking and another for DC-link voltage control). The proposed hybrid renewable energy source inverter is connected to single-phase grid via proper control systems. The complete system is simulated using MATLAB/SIMULINK and the results are presented in detail.展开更多
New voltage-controlled floating inductors employing CFOAs and an analog multiplier have been presented which have the attractive features of using a canonic number of passive components (only two resistors and a capac...New voltage-controlled floating inductors employing CFOAs and an analog multiplier have been presented which have the attractive features of using a canonic number of passive components (only two resistors and a capacitor) and not requiring any component-matching conditions and design constraints for the intended type of inductance realization. The workability and applications of the new circuits have been demonstrated by SPICE simulation and hardware experimental results based upon AD844-type CFOAs and AD633-type/MPY534 type analog multipliers.展开更多
文摘Electrical Capacitance Tomography (ECT) determines the dielectric permittivity of the interior object depending on the measurements of exterior capacitance. Generally, the electrodes are placed outside the PVC cylinder where the medium to be imaged is present;but in ECT using inter-electrode capacitance measurements can be achieved by placing inside of the dielectric medium. In the proposed ECT system, the ECT sensor is modeled using ANSYS software and the model is implemented in real ECT system. For each step of measurement, a stable AC signal is applied to a pair of electrodes that form a capacitor. The novel system is to measure the capacitance range variation in picofarad and the corresponding voltage ranges from 1 volt to 4 volts. The switching speed of all combinational electrodes is implemented using embedded system to achieve higher speed performance of AC ECT system which eliminates the drift and stray capacitance error. This is yielding the original image of unknown multiphase medium inside the electrodes using Lab VIEW. This paper investigates several advantages such as improved overall system performance;simple structure, avoids stray capacitance effect, reduces the drift problem and achieves high signal to noise ratio.
文摘In this paper, a novel 10 Transistor Static Random Access Memory (SRAM) cell is proposed. Read and Write bit lines are decoupled in the proposed cell. Feedback loop-cutting with single bit line write scheme is employed in the 10 Transistor SRAM cell to reduce active power consumption during the write operation. Read access time and write access time are measured for proposed cell architecture based on Eldo SPICE simulation using TSMC based 90 nm Complementary Metal Oxide Semiconductor (CMOS) technology at various process corners. Leakage current measurements made on hold mode of operation show that proposed cell architecture is having 12.31 nano amperes as compared to 40.63 nano amperes of the standard 6 Transistor cell. 10 Transistor cell also has better performance in terms of leakage power as compared to 6 Transistor cell.
文摘Secured Two Phase Geographic Greedy Forwarding (SecuTPGF) is a geographic greedy forwarding protocol for transmitting multimedia data stream in Wireless Multimedia Sensor Networks (WMSN) in a secure and reliable manner. Cryptographic and MAC authentication mechanisms are used to implement security for both node and message authentication. In this paper, a modified version of SecuTPGF, the GSTP routing provides security for both node and message authentication by using MD5 algorithm with a reduced computation power. In SecuTPGF, two different algorithms are used for node and message authentication, and GSTP routing uses “MD5Algorithm” for both node and message authentication. Using MD5 algorithm for node and message authentication, the average number of transmission paths increased and average number of hops used for transmission decreased when compared to the SecuTPGF. By conducting security analysis & evaluation experiments, the effectiveness of GSTP routing algorithm is proved.
文摘Induction motor is the most sought after motor in the industry for excellent performance characteristics and robustness. Developments in the Power Electronic circuitry have revolutionised the induction motor industry leading to the developments in various control strategies and circuits for motor control. Direct Torque Control (DTC) is one of the excellent control strategies preferred by industries for controlling the torque and flux in an induction machine. The main drawback of DTC is the presence of torque ripple which is slightly more than the acceptable limit. There are various parameters that introduce ripples in the electromagnetic torque, one of them being the type of inverter circuit. There are various types of inverter circuits available and the effect of each of them in the production of torque ripple is different. This work is an attempt to identify the influence of various multilevel inverter circuits on the torque ripple level and to propose the best inverter circuit. The influence of multilevel diode clamped inverter and cascaded H bridge inverter circuits on torque ripple minimization, is analysed using simulation studies for identifying the most suitable multilevel inverter circuit which gives minimum torque ripple. The results obtained from the simulation studies are validated by hardware implementation on 0.75 kW induction motor.
文摘Consumption of the electric power highly depends on the Season under consideration. The various means of power generation methods using renewable resources such as sunlight, wind, rain, tides, and waves are season dependent. This paves the way for analyzing the demand for electric power based on various Seasons. Many traditional methods are utilized previously for the seasonal based electricity demand forecasting. With the development of the advanced tools, these methods are replaced by efficient forecasting techniques. In this paper, a WEKA time series forecasting is being done for the electric power demand for the three seasons such as summer, winter and rainy seasons. The monthly electric consumption data of domestic category is collected from Tamil Nadu Electricity Board (TNEB). Data collected has been pruned based on the three seasons. The WEKA learning algorithms such as Multilayer Perceptron, Support Vector Machine, Linear Regression, and Gaussian Process are used for implementation. The Mean Absolute Error (MAE) and Direction Accuracy (DA) are calculated for the WEKA learning algorithms and they are compared to find the best learning algorithm. The Support Vector Machine algorithm exhibits low Mean Absolute Error and high Direction Accuracy than other WEKA learning algorithms. Hence, the Support Vector Machine learning algorithm is proven to be the WEKA learning algorithm for seasonal based electricity demand forecasting. The need of the hour is to predict and act in the deficit power. This paper is a prelude for such activity and an eye opener in this field.
文摘In the field of analog VLSI design, current conveyors have reasonably established their identity as an important circuit design element. In the literature published during the past few years, numerous application have been reported which are based on a variety of current conveyors. In this paper, an oscillator circuit has been proposed. This oscillator is designed using a single positive type second generation current controlled current conveyor (CCCII+). A CCCII has parasitic input resistance on it’s current input node. This resistance could be exploited to reduce circuit complexities. Thus in this accord, a novel oscillator circuit is proposed which utilizes the parasitic resistance of the CCCII+ along with a few more passive components.
文摘In this paper, four new first order voltage mode cascadable allpass sections are proposed using single active element and three grounded passive components, ideal for IC implementation. The active element used is a fully differential current conveyor. All the proposed circuit possess high input and low output impedance feature which is a desirable feature for voltagemode circuits. Nonideality aspects and parasitic effects are also given. As an application, a multiphase oscillator is designed. The proposed circuits are verified through PSPICE simulation results using TSMC 0.35 µm CMOS parameters.
文摘Classifying the data into a meaningful group is one of the fundamental ways of understanding and learning the valuable information. High-quality clustering methods are necessary for the valuable and efficient analysis of the increasing data. The Firefly Algorithm (FA) is one of the bio-inspired algorithms and it is recently used to solve the clustering problems. In this paper, Hybrid F-Firefly algorithm is developed by combining the Fuzzy C-Means (FCM) with FA to improve the clustering accuracy with global optimum solution. The Hybrid F-Firefly algorithm is developed by incorporating FCM operator at the end of each iteration in FA algorithm. This proposed algorithm is designed to utilize the goodness of existing algorithm and to enhance the original FA algorithm by solving the shortcomings in the FCM algorithm like the trapping in local optima and sensitive to initial seed points. In this research work, the Hybrid F-Firefly algorithm is implemented and experimentally tested for various performance measures under six different benchmark datasets. From the experimental results, it is observed that the Hybrid F-Firefly algorithm significantly improves the intra-cluster distance when compared with the existing algorithms like K-means, FCM and FA algorithm.
文摘In Dynamic Economic Load Dispatch (DELD), optimization and evolution computation become a major part with the strategy for solving the issues. From various algorithms Differential Evolution (DE) and Particle Swarm Optimization (PSO) algorithms are used to encode in a vector form and in sharing information and both approaches are based on the master-apprentice mechanism for the Dual Evolution Strategy. In order to overcome the challenges like the clustering of PSO, optimization problems and maximum and minimum searching, a new approach is developed with the improvement of searching and efficient process. In this paper, an Enhanced Hybrid Differential Evolution and Particle Swarm Optimization (EHDE-PSO) is proposed with Dynamic Sigmoid Weight using parallel procedures. A hybrid form of the proposed approach combines the optimizing algorithm of Enhanced PSO with the Differential Evolution (DE) for the improvement of computation using parallel process. The implementation and the parallel process are analyzed and discussed to gather relevant data to show the performance enhancement which is better than the existing algorithm.
文摘The paper focuses on the design and Field Programmable Gate Array (FPGA) implementation of embedded system for time based dual encryption scheme with Delay Compulsion Function (DCF) and also illustrates the application of DCF in time based cryptography. Further, the strength of the time based FPGA encryption algorithm with and without using DCF is analyzed using a Nios II processor. This proposed scheme enhances the security of vital data against Brute force attack by incorporating a temporal key distribution where two different keys encrypt the data simultaneously, one being the regular key and the other being the time. The time is included using a dynamically varying number of shifts thereby allowing the system to wait for the duration and this forms the second dimension of the key. Presently, available encryption systems suffer from Brute Force attack in which all the key combinations are tried in order to find the correct key. In such a case, the time taken for breaking the key depends on the speed of the system used for cryptanalysis. The proposed system adds complexity by using dynamically varying sequence of operations, by including the time as a second dimension of the key besides minimizing the possibility of Brute Force attack and increasing the time required for cryptanalysis irrespective of the system capability. As the proposed system needs concurrent execution and real time processing, the system is implemented using Altera Stratix II FPGA and the results are presented.
文摘The static flow resistivity is a fundamental parameter for measuring and classifying the sound absorption behavior of various types of materials. Several methods have been developed for measuring the static flow resistivity acoustically. Most of these methods cannot be implemented directly in the standard tubes which are widely used for measurements of sound absorption coefficients and impedance as defined in ISO 10534.2. The accuracy of the proposed method and the tube is verified through finite element analysis and the feasibility to determine the static flow resistivity is validated through experiments. It is validated that the accuracy of the proposed method is highly dependent on the position of the acoustic center of the measurement microphones and the accuracy can be enhanced by increasing the back cavity depth and/or decreasing the measurement frequency.
文摘In this modern era, power generation seems to be a very demanding factor. New models and methods have been proposed to derive from various natural and manmade resources. In such instances, this paper gives a detailed report on the power generation from Micro Turbines. Micro turbine plays a very important role in electric power generation. Especially they are used in the combined cycle process power plants. The parameters of Rowen’s model 265-MW single shaftheavy duty gas turbines which are used in dynamic studies are estimated in this paper using the operational and performance data. These data are also used to briefly explain the extraction of parameters of the used model. Micro turbine parameters are approximated using simple thermodynamics assumptions. Micro turbine power generation seems to be an uprising and a promising source and an exact design with a perfect model is capable of producing the highest efficiency. Thus this paper is proposed on the aspects of social awareness to elaborate the control design of Micro Turbine Power Generation System. The parameters of micro turbine models are derived and the results of several simulated tests using Matlab/Simulink are presented.
文摘A new circuit for realization of universal current-mode filter using current Follower Transconductance Amplifiers (CFTAs) is presented. The proposed circuit realizes current-mode low pass, high pass and band pass filter functions simultaneously with a single current source at the input. The band reject and all pass filters can also be obtained from the proposed circuit without any extra hardware. The proposed circuit employs three passive grounded elements and two CFTAs. Linear electronic control of natural frequency ω0 is available in the proposed circuit. The quality factor can be independently adjusted through grounded resistor. The proposed circuit employs two grounded capacitors and a grounded resistor along with two CFTAs. The grounded resistor can be replaced by an OTA based circuit for linear electronic control of quality factor Q0. The circuit exhibits low active and passive sensitivities for ω0 and Q0. Simulation results are obtained using PSPICE software which is in conformity with the theoretical findings.
文摘Processes of high-frequency (HF) heating are examined and its parameters for the soldering of electronic modules are optimized. The advantages of HF heating are the following: selectivity by skin-effect;high density of energy;process- ing in any environment, including vacuum or inert gas;high ecological cleanliness, improvement solder flowing by electrodynamics forces increase the quality of soldering connections. Investigation of HF electromagnetic heating has allowed to optimize heating speed in local zones of soldering connections formation and to improve their quality due to joint action of superficial effects and electromagnetic forces.
文摘This work summarizes the structure and operating features of a high-performance 3-stage dual-delay-path (DDP) voltage-controlled ring oscillator (VCRO) with self-biased delay cells for Phase-Locked Loop (PLL) structurebased clock generation and digital system driving. For a voltage supply V<sub>DD</sub> = 1.8 V, the resulting set of performance parameters include power consumption P<sub><sub></sub>DC</sub> = 4.68 mW and phase noise PN@1MHz = -107.8 dBc/Hz. From the trade-off involving P<sub>DC</sub> and PN, a system level high performance is obtained considering a reference figure-of-merit ( FoM = -224 dBc/Hz ). Implemented at schematic level by applying CMOS-based technology (UMC L180), the proposed VCRO was designed at Cadence environment and optimized at MunEDA WiCkeD tool.
文摘Voltage divider biasing common emitter amplifier is one of the core contents in analog circuit curriculum, and almost all of traditional textbooks apply approximate calculation method to estimate all characteristic parameters. In calculating quiescent point, transistor base current is generally ignored to get the approximate base potential and emitter current, then other operating parameters, and AC small signal parameters can be acquired. The main purpose of this paper is to compare traditional and Thevenin equivalent methods and to get the difference of the two methods. A Formula is given to calculate the error of the traditional method. Example calculating reveals that the traditional method can generate an error about 10%, and even severe for small signal amplifier with higher quiescent point.
文摘In large inter connected power systems, inter-area oscillations are turned to be a severe problem. Hence inter-area oscillations cause severe problems like damage to generators, reduce the power transfer capability of transmission lines, increase wear and tear on network components, increase line losses etc. This paper is to maintain the stability of system by damping inter-area oscillations. Implementation of new equipment consists of high power electronics based technologies such as FACTs and proper controller design has become an essential to provide better damping performance than Power System Stabilizer (PSS). With development of Wide Area Measurement System (WAMS), remote signals have become as feedback signals to design Wide Area Damping Controller (WADC) for FACTs devices. In this work, POD is applied to both SVC and SSSC. Simulation studies are carried out in Power System Analysis Toolbox (PSAT) environment to evaluate the effectiveness of the FACTs controller in a large area power system. Results show that extensive analysis of FACTs controller for improving stability of system.
文摘A new Single-Resistance-Controlled (SRC) sinusoidal oscillator using single Voltage Differencing-Differential Input Buffered Amplifier (VD-DIBA), only four passive components (two capacitors and two resistors), is presented. The proposed structure provides the following advantageous features: 1) independent control of oscillation frequency and condition of oscillation and 2) low active and passive sensitivities. The effects of non-idealities of the VD-DIBA on the proposed oscillator have also been investigated. The proposed SRC sinusoidal oscillator has been checked for robustness using Monte-Carlo simulation. SPICE simulation results have been included using 0.35 μm MIETEC technology to confirm the validity of the proposed SRC sinusoidal oscillator.
文摘This paper introduces a novel single-phase asymmetrical multilevel inverter suitable for hybrid renewable energy sources. The proposed inverter consists of two isolated DC sources and six power semiconductor controlled switches. The suggested inverter is capable of generating seven-level output when the input DC voltage is taken in the ratio of 1:2. The higher magnitude DC source is fed from Photo Voltaic (PV) panels, whereas the lower magnitude DC source is fed from Wind Turbine (WT) driven Permanent Magnet DC (PMDC) generator. Both the renewable energy sources are connected to the inverter via two DC-DC boost converters connected in cascade (i.e. one for maximum power point tracking and another for DC-link voltage control). The proposed hybrid renewable energy source inverter is connected to single-phase grid via proper control systems. The complete system is simulated using MATLAB/SIMULINK and the results are presented in detail.
文摘New voltage-controlled floating inductors employing CFOAs and an analog multiplier have been presented which have the attractive features of using a canonic number of passive components (only two resistors and a capacitor) and not requiring any component-matching conditions and design constraints for the intended type of inductance realization. The workability and applications of the new circuits have been demonstrated by SPICE simulation and hardware experimental results based upon AD844-type CFOAs and AD633-type/MPY534 type analog multipliers.
