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In an energy-constrained wireless sensor node, the use of ARQ (Automatic Repeat reQuest) protocol will lead to retransmissions when an attempt to send a packet fails. In an indoor wireless environment, the channel conditions chang...
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In an energy-constrained wireless sensor node, the use of ARQ (Automatic Repeat reQuest) protocol will lead to retransmissions when an attempt to send a packet fails. In an indoor wireless environment, the channel conditions change very slowly. This block-fading effect may lead to subsequent retries also failing, which adds to the total energy expenditure of transmission. The received signal power and therefore the ratio of the average bit energy and noise power spectral density (E_b/N_0) values may also change over time, mainly due to obstructions, partitions and human movement between the transmitter and the receiver. The proposed adaptive power control algorithm does away with channel estimation methods before transmission, and was studied using just four of the output power levels available in CC2420 transceiver module. It is designed to meet the challenge of responding to an unknown and variable radio channel in an energy-efficient manner. The adaptive protocol uses past transmission experience or memory to decide the power level at which the new packet transmission will start. Signal strength measurements from real world indoor radio environment were combined with the adaptive algorithm and used as the basis for experiments described in this paper. The results obtained show that such a state-based approach can outperform the fixed-power transmissions in terms of cost and delay for a given packet success rate.
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This proposed work is based on the design and development of pic-microcontroller and Second Harmonics Injection Based full bridge inverter with rated frequency output. The proposed hardware model shows a low THD with minimum filte...
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This proposed work is based on the design and development of pic-microcontroller and Second Harmonics Injection Based full bridge inverter with rated frequency output. The proposed hardware model shows a low THD with minimum filter requirement and reduction of sub-harmonics in the system. The developed inverter is tested with resistive, inductive, and motor load.
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Information of the Available Transfer Capacity (ATC) is very important in the Deregulated Environment (DE). In this paper, ATC calculation is emphasized in view of the Optimal Power Flow (OPF) technique through some soft computati...
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Information of the Available Transfer Capacity (ATC) is very important in the Deregulated Environment (DE). In this paper, ATC calculation is emphasized in view of the Optimal Power Flow (OPF) technique through some soft computational methods viz. Biogeography-Based Optimization (BBO) and Gray Wolf Optimization (GWO). The ATC is the key factor on the basis of the effect of transaction on transmission to allow or disallow bilateral transmission transection. The OPF has many objectives in the DE with open market conditions and these calculations aid to Independent System Operators (ISO) to handle the congestion threat on the transmission lines and assure system security and reliability. The two methods of soft computing, i.e., BBO and GWO are applied to find out the aforesaid criteria in the ATC calculation through the OPF, a corrective tool, which hints a new generation schedule to resist congestion and gives clues to the values of controlled parameters (e.g. active power generations, tap setting, reactive power injection) to avoid the violation of power system constrains (bus voltage limit and reactive power injection limit). The proposed methods are tested on WSCC 3 machine 9-bus and IEEE 30 bus test systems to evaluate ATC and their results, which are compared and it is observed that the GWO results are better than those obtain by BBO in both cases.
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In this paper, Colliding Bodies Optimization (CBO) technique is applied for finding the most promising optimal set of linear phase FIR filter coefficients. CBO is a class of meta-heuristic search technique which is free from any k...
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In this paper, Colliding Bodies Optimization (CBO) technique is applied for finding the most promising optimal set of linear phase FIR filter coefficients. CBO is a class of meta-heuristic search technique which is free from any kind of internal parameter and governed by the conservation law of momentum of colliding bodies. In order to establish the superiority of CBO over other optimization techniques, performance of CBO for FIR filter design is compared with the other techniques namely, Real Coded Genetic Algorithm (RGA), Particle Swarm Optimization (PSO) and Differential Evolution (DE). 20th order Bandstop (BS) FIR filter is designed with the proposed CBO and other afore-mentioned algorithms individually for the comparison of efficiency in performance of optimization techniques. A comparative study of simulation results reveals the optimization efficacy of the CBO over the other optimization techniques for the solution of the multimodal, non-differentiable, non-linear, and constrained FIR filter design problem.
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Stator winding inter-turn faults contribute to a major percentage of induction motor failure in the industries. A cross correlation technique based induction motor stator winding fault identification scheme has a significantly low...
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Stator winding inter-turn faults contribute to a major percentage of induction motor failure in the industries. A cross correlation technique based induction motor stator winding fault identification scheme has a significantly low computational burden that has been proposed in this paper. Presented scheme has been found to identify the inter turn fault conditions involving minor number of turns in three phase induction motor stator winding. Experimentally obtained, the three phase currents of the induction motor under healthy and faulty conditions were analyzed employing a suitably designed FIR digital filter and cross correlation technique. Captured motor current signals of the faulty phase were fed to the designed fault identification algorithm implemented in the form of a MATLAB program. The entire scheme has been found to identify stator winding inter-turn fault conditions quite efficiently and, thus, responses of cross-correlation between filtered motor currents under healthy and faulty conditions that have been proposed as an effective indicator for identifying such faults of varying severity.
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With the recent requirements of bulk power transfer, HVDC transmission lines has become more popular than the conventional HVAC transmission lines due to their ease of operation and certain benefits like more power transfer capabi...
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With the recent requirements of bulk power transfer, HVDC transmission lines has become more popular than the conventional HVAC transmission lines due to their ease of operation and certain benefits like more power transfer capability with same Right of Way, etc. One of the ways to incorporate the new HVDC transmission lines is to add them to the same mechanical poles of the existing HVAC networks leading to formation of a hybrid HVAC-HVDC transmission corridor. Also due to lack of geographical area, many a times there is a probability that the new HVDC transmission lines will be erected in close proximity of existing HVAC lines. When an AC line approaches a DC line, interferences would be generated upon the DC line due to the electromagnetic induction between the AC and DC lines. The interference includes the transverse voltage caused by capacitive coupling, the longitudinal electromotive force, and the fundamental frequency current on the DC line caused by inductive coupling. Thus elaborative study of this effects is required to understand them in both steady state and fault conditions. This becomes more important as many HVDC projects are operational or is going to be added soon to Indian Power Grid. The paper presents the work done in this area and scope of work that could be done for Indian Power Grid in this area. Focus of the study is to identify the prominent effects during steady state and fault conditions.
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In recent times, dielectric response measurements have gained immense attention for assessment of transformer oil-paper insulation condition. Time domain polarization measurements are one of the most popular dielectric testing tec...
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In recent times, dielectric response measurements have gained immense attention for assessment of transformer oil-paper insulation condition. Time domain polarization measurements are one of the most popular dielectric testing techniques for the purpose. For accurate interpretation of test data various mathematical models of the dielectric response process have been proposed by various researchers over the years. Frequency domain spectroscopic results obtained from mathematical transformation of the time domain data has been found to be useful in analyzing dielectric test results. In complex dielectrics, it seems however, that the overall response be represented by a distribution of relaxation times (or frequencies), rather than a single "average" response characteristic. The present contribution provides in brief, the mathematical background for estimating the functions representing distribution of relaxation frequencies from dielectric response measurement data and further transforming it to frequency domain spectrum. Experimental results on laboratory scaled down models and also on real transformers have been presented to support the theoretical formulations.
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Image segmentation among overlapping land cover areas in satellite images is a very crucial task. Detection of belongingness is the important problem for classifying mixed pixels. This paper proposes an approach for pixel classifi...
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Image segmentation among overlapping land cover areas in satellite images is a very crucial task. Detection of belongingness is the important problem for classifying mixed pixels. This paper proposes an approach for pixel classification using a hybrid approach of Fuzzy C-Means and Cellular automata methods. This new unsupervised method is able to detect clusters using 2-Dimensional Cellular Automata model based on fuzzy segmentations. This approach detects the overlapping regions in remote sensing images by uncertainties using fuzzy set membership values. As a discrete and dynamical system, cellular automaton explores the uniformly interconnected cells with states. In the second phase of our method, we utilize a 2-dimensional cellular automaton to prioritize allocations of mixed pixels among overlapping land cover areas. We experiment our method on Tilaiya Reservoir Catchment on Barakar river for the first time. The clustered regions are compared with well-known FCM and K-Means methods and also with the ground truth knowledge. The results show the superiority of our new method.
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Fractional-order PID controller is a generalization of classical integer order PID controller using the concept of fractional calculus. FOPID controller is far more superior to its integer order counterpart, besides setting propor...
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Fractional-order PID controller is a generalization of classical integer order PID controller using the concept of fractional calculus. FOPID controller is far more superior to its integer order counterpart, besides setting proportional, integral, and derivative gain; it has two more parameters that is the order of integrator λ and differentiator μ, which widens the scope of control system design. This paper gives an overview of the various tuning method of FOPID controller available in literature. The tuning method include: Ziegler Nichol type tuning rule, Padula and Visioli method, frequency domain design, time domain design, and IMC tuning. The difficulties in the implementation of FOPID controller has also been indicated.
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This paper introduces a new Digital Phase Lock loop (DPLL) in the presence of the three discrete energy separation algorithms, DESA-la, DESA1, and DESA2 modules, with the incorporation of the Teager Energy Operator (TEO). An addit...
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This paper introduces a new Digital Phase Lock loop (DPLL) in the presence of the three discrete energy separation algorithms, DESA-la, DESA1, and DESA2 modules, with the incorporation of the Teager Energy Operator (TEO). An additional phase modulation input, along with its frequency modulation input, is present in the digitally controlled oscillator of the loop. The incorporation of DESA module and phase modulation input in the DPLL is an entirely new proposal in the design of the DPLL. DPLL with DESAs are simulated in MATLAB SIMULINK environment. The new model is capable of demodulating the Frequency Modulated (FM) signal with proper perfection and has achieved a faster accusation time for the frequency step signal. Superior output Signal to the Noise Ratio (SNR) is also achievable in the modified DPLL.
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