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This paper analyzes the characteristics of chaotic oscillation of the second-order model of the power system, and presents an improved adaptive sliding mode control approach based on relay characteristic function. It restrains the high frequency chattering in sliding mode control. Lyapunov stability theory is used to prove the stability of the power system under control. The simulation results demonstrate that the proposed approach could effectively control the chaotic oscillation of the system and suppress chattering.

UHF RFID is becoming the main stream of passive RFID applications. Reader is a key component of a RFID application system. Based on the ARM9 chip S3C2440, the UHF reader ASIC AS3990 and a battery charger 9-channel programmable DC-DC power management chip SMB122, a low-power handheld UHF RFID reader is designed and implemented in this paper. In addition to long enough read range, the power consumption is also important for a handheld RFID reader. A low-power control program is analysed and designed in detail in this paper.

Radio Frequency Identification (RFID) has many perfect features such as completely non-contact, high recognition rate, bulk-storage memory, securely access and easily be integrated with existing management information system, etc. It has widely been applied in many fields especially in logistics and product quality tracking systems. The research on the application of RFID in agricultural seed quality management was studied in this paper, which included the cases from the seed's cultivation, storage, transportation to it's quality supervision by related enforcement and supervision departments, even to quality confirmation and plant guide for the last end user - farmer, also analyzed several key technologies for the using of RFID in seed quality tracking system, such as the function design, tag type choosing, frequency picking, protocol selecting, data security design, anti-collision technology planning etc. Finally, several valuable conclusions were achieved.

The electronic information display console is an important device displaying integrated information on some type of large-scale ship. The human-computer interface (HCI) design that is not good enough will cause inefficiency or injury to the operators. If the deficiency is discovered while working, it will cost much labor, money and time. The virtual simulation method is tried to use evaluating the HCI design. Set the evaluation criteria on the basis of ergonomics theories such as the characteristic of human motion. Establish the models on CATIA platform, set the parameters in the Human Model Module and run the simulation. Analyze the results of the simulation according to the ergonomics theories such as the dynamic body measurement, the standards of the workspace design, and bring out the suggestions such as reducing the height by approximately 230mm of the screen. This method could be well used to evaluate the HCI design of other similar type of devices in the control room.

In this paper, we propose a new frequency synchronization method for wireless orthogonal frequency division multiplexing (OFDM) systems. The method exploits the pilots' energy efficiently by collecting the energy leaked into the neighbor subcarriers, and provides the coarse and fine estimation of the frequency offset at the same time. Furthermore, an adaptive accumulator is used to attain a good tradeoff between the performance and the synchronization time. Computer simulation results demonstrate that the proposed method performs well at various Doppler frequency shifts with a fairly short synchronization time.