Advanced Materials Research Vols. 121-122

Abstract: Knowledge employee’s turnover forecast is a multi-criteria decision-making problem involving various factors. In order to forecast accurately turnover of knowledge employees, the potential support vector machines(P-SVM) is introduced to develop a turnover forecast model. In the model development, a chaos algorithm and a genetic algorithm (GA) are employed to optimize P-SVM parameters selection. The simulation results show that the model based on potential support vector machine with chaos not only has much stronger generalization ability but also has the ability of feature selection.

Abstract: Modal analysis, which is applied to verify the vibration characteristic of structures, is the basis of various dynamic analyses. In this paper, firstly, a cable-stayed space truss, consisting of stay cables, columns and space truss, is built in ANSYS. Secondly, modal analysis is performed to confirm the natural frequencies of the structure and 10 modes are extracted. Thirdly, a modal neutral file including all necessary information of flexible bodies is generated by ANSYS and then imported into ADAMS for further modal analysis. Finally, comparison of results between ANSYS and ADAMS are summarized and qualitative analysis is carried out aiming at the difference of natural frequencies between ANSYS and ADAMS. The simulation results indicate that the interface between the two tools has strong compatibility regardless of minor errors in it.

Abstract: The pose control system of robot is strictly required. This paper expatiate some methods of pose control, the design of hardware circuit and software with triaxial accelerometer and electronic compass. The results of field operation showed that the pose control system used electronic compass characteristics in high accuracy, sensitive response, stable starting running, compact structure and so on.

Abstract: Power-efficient multipliers are essential for low-power signal processing hardware and embedded digital system since they have high switching activity and contain large node capacitances, resulting in large power dissipation. This paper presents an adiabatic Booth array multiplier based on PAL-2N circuits. It is composed of Booth encoders, a multiplier array containing partial product generators and 1-bit (half and full) adders, and a final carry-lookahead adder. Full-custom layouts are drawn. The energy and functional simulations have been performed using the net-list extracted from their layouts. The simulation results show that the adiabatic Booth array multiplier attains large energy savings, compared with its counterpart without the booth encoder.

Abstract: In this paper, we analyze the data structure of design of matter-element model from the level of software design, combined with the features of the common used data structure and matter-element model in Extenics, finally propose a new data structure model, which adapt to computation, reasoning and transformation using matter-element model.

Abstract: Aiming at content-based audio retrieval (CBAR) applications, a robust audio hashing scheme is proposed. First the audio is divided to frame by fixed length and then low-frequent and high-frequent components are obtained by three-level lifting-based wavelet transformation in every frame. Secondly the audio frame is approximately represented as a product of a base matrix and an encoding matrix, or coefficient matrix, using non-negative matrix factorization (NMF). Finally the sum of each column in the coefficient matrix is calculated, which is then quantized to produce one bit of the hash sequence. Experiment results show that the proposed scheme is robust against Mp3 compression, Real compression, filtering, amplitude compression, equalization, echo, etc. It is insensitive to small local change, and therefore is suitable for distinguishing different audios.

Abstract: This paper searched open loop stability on hybrid synchronous motor which is made of a permanent magnet part and a reluctance part, there is important influence for the ratio k, the fraction length of the permanent magnet part, and the displaced angle α, the between the two part d-axis, the small-signal mathematics model was derived based on d-q reference frame, and optimized the appropriate k and α value considering the stability and the harmonic distortion factor (THD), The simulation results show that the model is correct.

Abstract: This paper compares the electromagnet torque characteristics of ALA+PM rotor synchronous motor with the conventional permanent magnet motor, the former holds on linearity relationship with the increase of the stator flux linkage, but the later needs restrict condition. The direct electromagnet torque control is the best control method for ALA+PM rotor synchronous motor, but the stator current can increase if the stator flux linkage is bigger or smaller than magnet flux linkage, the maximum torque current percent ampere control method is used to overcome the disadvantage.

Abstract: In the paper, the multi-layer situation decision-making method of complex system is firstly introduced. Then, the development of the multilayer situation decision support system is put forward. At last, as a test example and an application, we use the MSDSS to achieve the optimization of the economic system in China.

Abstract: Electro-mechanical hybrid power controller (EMHPC) is a kind of switch with a breaker as mechanical switch and an insulated gate bipolar transistor (IGBT) as solid-state switch. It is a key element of electrical load management center (ELMC) of the more electric aircraft (MEA). On the condition of high voltage (270VDC) and large current (200A), the proposed EMHPC in this paper features great simplicity and reliability. It has no contact chatter when the controller is turned on or off, main circuit will be shut down when contactor fault happens, it also has the feature of over-current protection for solid state switching device when large current occurs in the working circuit. The proposed controller is supported by experimental results.