Recent Advances in Electrical & Electronic Engineering - Volume 11, Issue 2, 2018

Background: Harris corner detection extracting corner features based on the characteristic value of the second order matrix, is regarded as one of the most successful algorithms in corner detection. Methods: OTSU algorithm abbreviation of the maximum variance between clusters can calculate the maximum variance to distinguish the background area and the target area based on the image gray histograms. To obtain the adaptive threshold, Harris needs to artificially select threshold and threshold estimation becomes very difficult. Results: To solve these problems, OHO algorithm is proposed in this paper which aims to optimize the Harris algorithm based on OTSU. The OHO algorithm combines the characteristics of the high accuracy of Harris algorithm and the adaptive threshold selection of OTSU. Conclusion: Experiments show that the OHO algorithm can detect more details and authentic corners, and has better adaptability and robustness than traditional Harris.

Background: Switched reluctance motors have a strong nonlinear performance due to their structure and operation mode. The performance and control strategy of this kind of motor are obviously different from those traditional strategies. As a result, the accurate model and high performance control of the switched reluctance motor prove to be very important and has obtained wide researches. Method: A kind of switched reluctance motor based on PID neural network control strategy is proposed, which combines artificial fish swarm and particle swarm optimization to optimize weights and thresholds of BP neural networks. Results: Speed responses of the improved BP algorithm have no overshoot, have a smooth transition to the steady state and eliminate the oscillation phenomena which is in the PID control. Conclusion: Besides, it reduces time of transient process to improve the response speed. Antiinterference ability and robustness are obviously superior to the PID control.

Background: With the development of internet era, the combination of the basketball teaching and multimedia becomes more closer, and the use of computer multimedia technology to effectively test the tactical awareness has been widely concerned. Methods: In this paper, based on the analysis of the current development trend of basketball, we can conclude that basketball tactical awareness training is more important. However, the multimedia technology is still insufficient to the basketball tactical consciousness training. Aiming at the deficiency, this paper designs a multimedia aided training system of basketball tactical consciousness based on the professional theory and technology. The systematic test method can objectively reflect students' basketball tactics consciousness level, using training methods, can improve the students' observation, analysis and decision making ability, and promote the formation of students' consciousness of basketball tactics in this system. Results: Finally, by using the method of fuzzy comprehensive evaluation in the system after the training of students, a score test was carried out to verify the effectiveness of this system.

Background: A new technology for indoor positioning is proposed in this paper by applying combined RFID (Radio Frequency ID) / IRID (Infrared ID) and spatial fluctuations of the ambient magnetic field. Due to the presence of interior reinforced concrete construction, furniture, electronics and other indoor subjects, the distribution of the magnetic field intensity is fluctuated. Methods: Based on the spatial fluctuations, a particle filter algorithm can be employed to locate the indoor target. However, the computation power required for positioning in a large area could be very high because of the complexity of the application of the particle filter. Results: Similar patterns of magnetic field in large area could also result in wrong location. Because of the short and tunable radiating range of the RF signal and the short response time of identification signal, the target may be positioned within a certain range by using RFID. Therefore, RFID/IRID positioning technique is introduced to approximate the position of the target and then particle filter is applied for precise positioning in the range of RFID/IRID signals. Conclusion: This can effectively reduce the number of required particles to carry out the particle filter algorithm, thereby reducing the amount of computation power, reducing the response time of the positioning and improving the accuracy of the estimated target position.

Background: A grid-tied strategy of matrix converter (MC) based on the dual-side current closed loop is presented here. Methods: This paper designs dual-closed-loop regulators in which source current and grid current are used as the outer-loop and the inner-loop controlled variables, derives the duty ratio expressions of MC in different time slot, and complete the prototype. The capacitor voltage and the inductance current of the filter are used as the state variables of the inner-loop in system and the virtual rectifier parameters of MC are corrected real time to improve accuracy and to get the unit input-power-factor when it is grid tied. Results: The paper studies the dynamic characteristics of the system in which the virtual-damping is applied, derives the augmented state feedback control equations and transfer functions, gets the optimized control parameters and more feasible closed-loop ac nodes, to enhance the stability of the system. Conclusion: The experiment results, which are involved in the source-side features, grid-tired process of MC, and load change response, show that the MC grid-tied system based on the new strategy has favorable features and unit-power-factor in both source and grid sides.

Background: The Internet of Things (IoT) has been heralded as the “next big thing” waiting to be realized. IoT revolves around increased machine-to-machine communication and it encompasses various embedded sensorsand actuators that assist users in monitoring and controlling objects remotely in many fields and applications. Methods: IoT's special characteristics introduce challenges in the field of retrieval technology. These challenges constitute of real-time data retrieval with the huge amount of data that can be produced from the sensors. This paper explains the design concepts used to develop a search engine for IoT to tackle these issues. The developed search engine appears to be promising. The performance of the network proved very powerful under normal conditions, however, it could not sustain heavy load under the stress test due to the restricted build of the Z1 motes. Results: The searching capability proved to be quite strong in terms of searching speed and acceptable results; however more tests need to be implemented especially in terms of parallel searching. The GUI is simple and produces multiple features, but lacks interactivity. The security aspect ensures the security of the database with the partial prevention of SQL injection attacks. Conclusion: However, more security measures are required to protect against eavesdropping and unauthentic clients.

Background: To aim at the deficiencies of traditional Z-Source Inverter (ZSI) with its voltage boost conversion ability being limited and huge inrush current existing during the startup under shoot-through state, a novel switched inductor type ZSI topology is proposed in this paper. Methods: The ZSI presented applies the change of working state of the diode in switched inductor to deliver the energy stored in the inductor to the loads during the shoot-through state such that the boost capacity of the inverter is enhanced, and the voltage stress on capacitor is reduced, dramatically. In addition, we also establish the corresponding mathematical model and design the relative control strategy, and then apply it in wind power system with Permanent Magnet Synchronous Generators (PMSG). Conclusion: Compared with the traditional ZSI, the simulation results indicate that the ZSI proposed not only can effectively improve voltage boost ability of the inverter to make the fan run in a wider range of wind speed, but also reduce the voltage stress on capacitor of the impedance network, dramatically, such that the cost of the converter device is for that reduced, and is a quite effective and available ZSI.

Background: A MOS transistor operating in weak inversion exhibits logarithmic behavior and could serve as replacement of bipolar transistors which have often been employed in implementing log domain circuits. However, threshold voltage restricts the operation of MOS based log domain circuits at low supply voltage which could be eliminated by floating gate transistors (FGMOS) at the cost of low gain, low output impedance and degraded bandwidth. These limitations can be further overcome by using quasi-floating gate MOSFET (QFGMOS).The log domain technique has been employed to enhance the dynamic range of analog circuits suitable of operation at low supply voltage. Methods: In this paper, we have designed QFGMOS based integrator and its performance has been compared with CMOS and FGMOS versions. The behavior of these circuits has been verified by using OrCAD PSpice with level 7 parameters for 0.13 μm technology obtained from TSMC with supply voltage of 1V. Results: It has been observed that QFGMOS based compressor and expander exhibits better performance as compared to their CMOS and FGMOS counterparts. Further QFGMOS based log domain integrator has been designed and its performance compared with that of CMOS and FGMOS based log domain integrators and found that QFGMOS based log domain integrator exhibits larger bandwidth (4.26 MHz) as compared to FGMOS (3.2 MHz) and it dissipates less power (88.7 μW) then FGMOS (0.114 mW) and CMOS (0.129 mW) based log domain integrators and could be useful for low voltage applications. Conclusion: In this paper functional blocks of log domain integrator like compressor and expander have been designed using CMOS, FGMOS, QFGMOS transistors and their performance studied through PSpice simulations. It has been observed that QFGMOS based compressor and expander exhibits better performance as compared to their CMOS and FGMOS counterparts. Further QFGMOS based log domain integrator has been designed and its performance compared with that of CMOS and FGMOS based log domain integrators.

Background: Outdoor-working insulators could be degraded due to the changes of the environmental factors. When it degrades to certain extent, the insulating property will reduce, thus the monitor of insulators' working condition which is of significance. Methods: This paper, designs a faulty detecting device based on “Solar Blind” UV pulse for transformer substation insulators and put forward a multivariant nonlinear regression analysis method to find the mathematical expression between degree of faulty insulators and distance, UV pulse, environment humidity. Through the establishment of the faulty insulators test model, this paper ranks the faulty insulators levels in the form of a percentage, which makes the test result clear and direct. Results: Experiment results show that, this mathematical relation can be the criterion of faulty insulators judgment. Conclusion: The result can provide research methods and ideas for the on-line assessment of substation insulators' degradation.

Background: Electrooculogram (EOG) signal is one of the bioelectric signals acquired from the human body to study the movements of eyes and also to design and develop assistive devices. These devices can be mobility devices, video gaming devices or any other assistive device. Methods: Assistive devices are especially designed for quadriplegic or spinal cord injured patients. Motors are one of the key components in the design of mobility devices. These motors are to be driven with the help of EOG commands. This paper explains the process of eliminating involuntary eye movements while driving the motors under the control of EOG signals. The system design is carried out in two ways. Initially the system is designed in such a way that the motors are driven even for involuntary eye movements which is a major drawback of the system. Conclusion: This drawback has been overcome successfully by introducing the moving average technique during classification of the EOG signals. The systems overall classification accuracy is also computed by constructing confusion matrix and has produced high sensitivity, specificity with overall average accuracy of 90.91%.

Background: This paper presents a novel spatio-temporal learning method to generate knowledge of fine-grained cultivation of Dendrobium officinale from large climatic sensor data. In recent years, datadriven precision agriculture, which is strongly connected with data mining techniques, has a great impact on traditional farming. Most of the environmental control methods in the green house are based on humanexperience. Methods: In the paper, fine-grained rules have been proposed to provide precise climate control in temporal dimensions during the growth of plants. Spatial and temporal information were combined together and analyzed. An unsupervised merging algorithm on time segments was proposed to learn optimal tags for classification, and then new data samples consisting of clustering labels were prepared for knowledge mining from the raw sensor data. Finally the climatic rules were built in the form of decision trees. Results: The experimental results show that about 80% climatic conditions in the past successful cultivation can be replicated to guide future cultivation by our decision rules. Conclusion: The knowledge cultivation can guarantee similar quality of Dendrobium officinale since it is especially important for the production of herb medicine.

Background: In this paper, synchronization is theoretically investigated in two quantum cascade semiconductor lasers coupled with delayed negative optoelectronic feedback. Synchronization characteristics and the influence of parameter mismatches on synchronization performances are investigated. Results: The results indicate that the complete synchronization can be realized under suitable system parameters. Through numerically studying synchronization quality and the influence of parameter mismatches on synchronization, the delay time of the transmitter, the delay time of the receiver, transmission time, coupling strength, and gain stages number have significant impact on the synchronization quality. Conclusion: Calculations indicate that correlation coefficient can be enhanced by high coupling strength, small stages number and similar delay times. The synchronization quality is sensitive to stages number value. In comparison with coupling strength, the mismatch in delay times has significant impact on the synchronization quality.

Background: NDN routers forward packets by using multiple components that contain names similar to those of URLs. Therefore, name lookup is a key issue in NDN research field. Method: In this study, we propose a name lookup method called as sum-up counting Bloom filter to reduce false positive rate and storage time for NDN. Results: Experimental results show the efficiency of the proposed method compared with conventional methods.

Background: In this paper, two enhanced current controlled instrumentation amplifiers are proposed. These circuits, which have no passive elements, use second-generation current controlled conveyors, as basic building blocks, and a grounded active resistance. Materials & Methods: The instrumentation amplifiers are positively affected by certain features of the current controlled conveyor, such as: simple structure, high frequency functioning, low supply voltage and low power dissipation. The proposed structures do not require matched resistors to reach a high common mode rejection ratio. They have wide bandwidth that remains unaffected by a current controlled differential gain. Results: Moreover, they offer high input impedance and low offset, which are a desirable features for instrumentation amplifiers. Accordingly, the proposed amplifiers are suitable for integrated circuit implementation in the medical field. The instrumentation amplifiers characteristics are confirmed through PSPICE simulation in order to sustain the theoretical results. Conclusion: A comparison with the structures presented in the literature is undertaken to highlight the benefits of our circuits.

Background: Many applications in voice processing have high inherent parallelism. Field programmable gate array (FPGA) has shown very high performance in spite of its low operational frequency by fully extracting the parallelism. Nevertheless, recent CPU and graphic processing unit (GPU) have also an inherent for high performance. Methods: In fact, it becomes possible to utilize the parallelism using multi-cores, which support improved single instruction multiple data (SIMD) instruction. Recent GPUs support a large number of cores, and have a potential for high performance in many applications. Our goals are at first to compare GPU and FPGA implementation of the linear prediction coding (LPC) algorithm, in order to understand the trade-off between the flexibility but relatively low speed of an FPGA and the high speed and fixed architecture of the GPU. Secondly, we try to apply various levels optimization from overlapping data transfers to fine-tuning operation sequences. Results: The experimental results highlight the relative strengths and limitations of the two systems. Conclusion: Our experiments show that, for several samples corresponding to several speeches coding, GPU manages speedups of up to 3x compared to the FPGA and around 35x compared to a sequential execution.

Background: This work presents results based on realistic data as inputs obtained from the NASA surface metrology consisting a PV-Wind hybrid system. Methods: This system includes PV and wind subsystems, load and a hybrid system. The system included a 3.6kW PV array and a 3.2kW wind turbine and collected realistic data from January to December 2015 from the NASA website at Manipal location (INDIA) to calculate the solar and wind power. The study simulated daily and monthly data, and validated the simulation results for the physical system. Two Boost converters transfer a maximum power of Wind Energy Conversion System (WECS) and Photo Voltaic (PV) system to DC link. These converters are operated based on Perturb and Observed (P & O) MPPT algorithm and with a change in duty cycle. Based on PQ control strategy, the single-phase voltage source inverter supplies power to the grid and maintains the DC link voltage 400V. Results: With LCL filter, the Total Harmonic Distortion (THD) of the load current was observed to be 1.66% and without filter, the THD of the load current was 25.66%. Conclusion: Total Harmonic Distortion (THD) of load voltage was 0.1 % with LCL filter and without filter, the load voltage THD was 60.76%.

Background: A W-band Sheet Electron Beam (SEB) Traveling-Wave Tube (TWT) based on Three-Slot Staggered-Ladder (TSTL) Coupled-Cavity Slow-Wave Structure (CC-SWS) is proposed in this paper. Methods: The high-frequency characteristics of TSTL CC-SWS are analyzed in detail. Well-matched input/output couplers that solve the problem of energy coupling between the SWS and the external circuit are designed. In addition, a Small Tunable Periodic Cusped Magnet (STPCM) system is used to focus the SEB, which is predicted to exhibit 100% beam transmission efficiency. Finally, the beam-wave interaction was studied with CST particle studio. Results: The results show that the SEB TWT can produce output power over 1.27kW within the bandwidth ranging from 90GHz to 99.5GHz, and the maximum output power is 2.8kW at 96.5GHz, corresponding to the maximum electronic efficiency of 11%.

Background: Face tracking technology has been paid more and more attention with the development of intelligent techniques. Many methods have been used for face tracking, including the particle filter algorithm and Particle Swarm Optimization (PSO). However, these methods generally ignore the motive and the optimal solution of the particle. Methods: A particle filter based on the improved Differential Evolution Algorithm (DEF) is proposed, preventing the particles from falling into the local optimum and considering the mobility of the face tracking problem. The performance is better than the particle swarm optimization algorithm by replacing resampling in particle filtering, which is caused by the use of the niche technology to solve the problem of moving peak optimization. Results: The results show that the proposed algorithm is better than the multi-agent co-evolution of particle filter, adaptive PSO particle filter and other current methods. Although the proposed algorithm increases the tracking time, it can achieve about 13 frames per second of the tracking speed. Conclusion: A particle filter algorithm has been combined with the improved DEF and niche technology to avoid the local optimum and to solve the moving peak optimization problem. The proposed algorithm provides the best tracking accuracy with an acceptable tracking speed.

Background: This paper presents a novel optimized Fractional-Order Proportional-Integral Derivative (FOPID) controller for controlling the terminal voltage of an automatic voltage regulator system. The parameters of the proposed controller are optimized using a recent meta-heuristic technique known as Grey Wolf Optimizer (GWO). Methods: A recent meta-heuristic technique known as Grey Wolf Optimizer (GWO) is used for fine tuning of FOPID controller parameters. Initial values of proportional gain (Kp), integral gain (Ki), and derivative gain (Kd) of the controller are tuned using Ziegler-Nichols (ZN) method where values of λ and μ are chosen randomly. A nonlinear fitness function consisting of rise-time, settling-time, maximum-overshoot and Integral of Time Square Error (ITSE) has been chosen as the fitness function for the proposed algorithm to get the optimum solution. Results: The proposed FOPID controller provides faster response (i.e. minimum rise-time (0.0292 sec.)), minimum settling time (0.1107sec.) and desired frequency domain characteristics (Gain margin=25.2, Phase margin=60.2). Conclusion: The proposed FOPID controller provide faster and better control action for AVR system. Additionally, it also improves the robustness of the system with respect to model uncertainties. Simulation results are validated with the existing techniques in the literature with the help of figures and also summarised in tables.