Advanced Materials Research Vols. 433-440

Abstract: Genetic algorithm (GA) is a meta-heuristic inspired by the efficiency of natural selection in biological evolution. It is one of the most widely used optimization procedure which has successfully been applied on a variety of complex combinatorial problems. The main drawback of GA, however, is its several tuning variables which need to be correctly set. The performance of GA largely depends on the proper selection of its parameters values; including crossover mechanism, probability of crossover, population size and mutation rate and selection percent. The objective of this research is to evaluate the effects of tuning parameters on the performance of genetic algorithm using the data collected as per Central Composite Design (CCD) matrix. To gather the required data, the proposed approach is implemented on a well-known travelling salesman problem with 48 cities. Then, regression modeling has been employed to relate GA variables settings to its performance characteristic. Analysis of Variance (ANOVA) results indicate that the function can properly represent the relationship between GA important variables and its performance measure (solution quality).

Abstract: A requirement elicitation is a task that helps a customer to define what is required, and then worked out with great care and nicety of detail. This paper surveys and evaluates some methods for eliciting requirements of computer based systems, what are the categories of these methods, what are the problems that each method involves. the solution of one method leads us to the next method so these methods are interrelated with each other .to avoid problems in one method we need another method so we can say combination of different methods can be used to elicited specific requirements. The insufficient requirements engineering process forms one important factor that cause the failure of an IT project. We elaborate a comparison of requirements development methods, evaluation criteria and also identify common factors that affect the method selection. Requirements are elicited through consultation with stakeholders so it certainly seems simple enough, But isn’t simple it is very hard.

Abstract: In this paper, absorbing the domestic and foreign research results of GPS positioning technology, it is based on further GPS measurements in the highway engineering theory and methods in a systematic study of the GPS data processing process. It also introduces the high-precision GPS data processing software GAMIT. It also gives and analyzes the highway GPS data processing results from control measurements.

Abstract: A kind of quasi-orthogonal space time block code for amplify-and-forward relay networks is analyzed in this paper. At the source, 4 single-antenna users transmit the quasi-orthogonal space time block code matrix. At the relay node, fast maximum-likelihood decoding algorithm is adopted and the decoded symbols are then encoded into quasi-orthogonal code which is transmitted through transmit antenna. At the destination, pair-wise decoding algorithm is utilized. Finally we compare the performance of the quasi-orthogonal space time block code in relay networks with that of the quasi-orthogonal space time block code in traditional communication system. Simulation results show that at the given BER of 10-3, the new code can provide about gain of 4dB and 1 dB comparing with that for the traditional quasi-orthogonal code, respectively. And at the given BER of 10-5, the new code can provide about gain of 4.6dB and 2.6dB comparing with that for the old quasi-orthogonal code, respectively.

Abstract: SVMs with kernel have been established with good generalization capabilities. This paper proposed a supervised product-image classification method based on SVM and Pyramid Histogram of words(PHOW). We tested several kernel functions on PI100 (Microsoft product-image dataset), such as linear, Radial Basis, Chi-square, histogram intersection and spatial pyramid kernel. Experimental results showed the effectiveness of our algorithm.

Abstract: Theory analysis method is adopted in this paper to review the development history of air-conditioning loads calculation, point out that the air-conditioning loads calculation went through from steady calculation to periodic unsteady calculation and then to new period of dynamic load calculation. Simulation calculation of air-conditioning cooling load have been developed deeply, and many software can be used to calculate the hourly cooling load about building. At last, The application of neutral network for prediction of cooling load in air conditioning systems have been introduced.

Abstract: The grounding capacitive current is one of the most important parameters of ungrounded neutral system. Usually this parameter is obtained with the method of additional capacitor or metal grounding. However, the former is complicated and the additional capacitor has negative effects on measurement results, and the later is dangerous when used in testing. In view of that, the paper proposes a new method to calculate grounding capacitance current based on the data of single-phase-grounding faults in power system with indirectly earthed neutral. This method reduces the error by using the least-square method .The ATP simulation results show that this method is accurate basically.

Abstract: The movement characteristics of traffic flow nearby have the important influence on the main line. The control method of expressway off-ramp based on Q-learning and extension control is established by analyzing parameters of off-ramp and auxiliary road. First, the basic description of Q-learning algorithm and extension control is given and analyzed necessarily. Then reward function is gained through the extension control theory to judge the state of traffic light. Simulation results show that compared to the queue lengths of off-ramp and auxiliary road, control method based on Q-learning algorithm and extension control greatly reduced queue length of off-ramp, which demonstrates the feasibility of control strategies.

Abstract: Multi-level inverter can output high voltage directly and can be connected without transformer, so it is applied more and more widely in high power situation. This paper presents a cascade H bridge seven-level parallel active power filter. This paper analyzes the principle of cascade H bridge multi-level inverter, designs a cascade H bridge seven-level SAPF based on CPS-SPWM, and the principle and the effect are simulated. The simulation results show that this system can compensate load harmonic current.

Abstract: In the high-speed train control system, the command information such as allowable running distance, time and speed can be sent by the global system for mobile communications for railways (GSM-R). This paper will propose the framework of real-time train scheduling and control based on model predictive control for the optimal speed set-points of high-speed trains. The rolling optimization process combines the genetic algorithm with the simulation of train operation to evaluate the performance of speed set-points, which can be easily implemented in the parallel computing environment for real-time processing. The conflict resolution at the crossing stations is modeled by and embedded in the combination of various speed set-points which are formed from virtual to simulation speed. The final actual speed of train is engendered based on the movement authority and running time through the system of automatic train protection (ATP). The simulation results demonstrate the favorable performance of proposed method.