Key Engineering Materials Vols. 439-440

Abstract: With the progress of human society and the rapid development of economy, the world's energy shortages have become increasingly prominent and the energy-saving and environmental protection has gradually become the priority over the social and economic area. How to achieve the rational and efficient use of energy, and protect the natural environment have become an important issue that all countries in the world concerned and confronted with presently. As one emerging technology steam condensate recovery can not only greatly improve the energy efficiency but also realize the conservation of water resources has been widely used in some developed countries in recent years. And it has achieved considerable economic and environmental benefits.

Abstract: An instability result of a problem in artificial intelligence is given by means of the analysis and computing method.

Abstract: A periodicity result of information signal is given by Liapunov’s second method.

Abstract: Global Positioning System（GPS）is able to identify real-time information of moving objects quickly and efficiently, such as longitude, latitude, altitude, time and so on. So it has to give the positioning and navigation of objects. This research uses GPS9540 receiver module to receive satellite signals. The time information and location information of this kind of GPS receiver module is GPRMC statement of NMEA-0183 standard format. We use AT89C51 Single Chip Microcomputer (SCM) of ATMEL Corporation as the core controller, and use the serial port of SCM to receive the time information and location information of GPS receiver module. We adjust the time difference information of the GPS receiver module, and finally display acquired location and time information through the liquid crystal display module (LCD). Actual operating results show that the system can decode GPS location information and time information correctly, and positioning information and time information is displayed on the LCD correctly. The system has good reliability and practicality, and it can be used for object location and navigation. This research first introduces the applications and theory of GPS as well as the extraction methods of GPS module output data. Then we introduce the system hardware block diagram and schematic, as well as system software flow chart and software programming, thus we achieve the key technology research of the GPS positioning system.

Abstract: In this paper the application of linear quadratic (LQ) optimal control based techniques to a thrust vectoring unmanned aerial vehicle (TV-UAV) control problem is considered. A general nonlinear dynamic model of the TV-UAV is built, which is different from the common UAV. The longitudinal and lateral linearization models are derived in a benchmark flight state. Two thrust deflections are considered as control variables, associated with the rudder control variables. LQ optimal control method based multivariable control system is designed for the attitude stability control problem. Simulations of a nonlinear model described UAV is carried out, results of which show the superiority of the hybrid control strategy, and also show that the TV-UAV has better properties than the common UAV, in the aspects of anti-disturbance and control efficiency.

Abstract: Power quality (PQ) analysis is the foundation of power system automation. The premise of power quality analysis is feature representation of power quality events. Time-frequency analysis (TFA) is very suitable for nonstationary signals analysis. The TFA of a PQ signal is to determine the energy distribution along the frequency axis at each time instant. This paper provides a status report of feature representation for PQ events by TFA methods, including short time Fourier transform (STFT), wavelet transform (WT) and S-transform (ST), overview the basic TFA theories for PQ analysis and compare the effectiveness of different TFA methodology. The expectation is that further research and applications of these TFA algorithms will flourish for PQ feature representation in the near future. The analysis direction and emphasis of studying are also put forward.

Abstract: Power quality waveform distortion detection is one of the most important works for power quality diagnosis. It is the basis to decide when to record the fault power quality signals. This paper presents a new method to detect waveform distortion by similarity measure. 6 types of typical power quality events are simulated to compare the effect of distortion detection. Simulation results show that the distance measure is suit to waveform distortion detection and normalized distance has the best effect of detection.

Abstract: In terms of the design of the Core Section, aiming at the half of the core circumcircle, for the case of the Core Section without the Cooling Oil Pan, this paper firstly establishes a non-linear programming model taking the objective function that the geometric cross-sectional area of the column core is the largest. Then, on the basis of analyzing the case of Cross Section with the Cooling Oil Pans another non-linear programming model is estabished to make the geometric cross-sectional area of the core column be the largest and the adjacent area of the two parts divided by the Cooling Oil Pans be equal as much as possible. And, the series of the section and the width and thickness of the silicon steel sheets at all levels are fixed while the effective cross-section of the core column is maximum. At last, to the two instances, this paper analyses the effects of the addition of the Cooling Oil Pans on the design for Cross Section.

Abstract: Retracted paper: One of the key points resulting in the success of differential evolution (DE) is its mechanism of different mutation strategies for generating mutant vectors. In this paper, we also present a novel mutation strategy inspired by the velocity updating scheme of particle swarm optimization (PSO). The proposed approach is called HDE, which conducts the mutation strategy on the global best vector for each generation. Experimental studies on 8 well-known benchmark functions show that HDE outperforms other three compared DE algorithms in most test cases.

Abstract: In order to solve the problem of group delay of filter design, this paper presents pre-distorted design method with Bessel function for coupled resonator filter and multiplexer with the maximally flat group delay characteristic. At the same time, the formulas and unitary parameter table of Bessel function has been gotten in this paper. The directly coupled resonator pass band filter and multiplexer can be achieved by using this approach. The design two examples are presented and the group delay is flat. The results validate its effectiveness.