Applied Mechanics and Materials Vols. 182-183

Abstract: Combined the characteristics of IEEE 802.15.4 standard and the IPv6 protocol, the paper designs a set of 6LoWPAN protocol stack software on single-MCU based on CC2430. This set of protocol stack is designed for industrial applications. This paper completes the fragmentation and reassembly, header compression and other basic functions of 6LoWPAN. Finally, with the typical application of industrial equipments, we build a practical test system to test the data communications of the 6LoWPAN protocol stack. And, it verifies the correctness and practicability of 6LoWPAN protocol.

Abstract: The big differences of the texture and shapes in the same type and certain similarities among heterogeneous types result in the difficult classification of fabric defects. Compared with traditional global statistical method, we put up a new solution, which makes use of the fabric defect local region features to keep the defect property and defect classification by Support Vector Machines (SVM). Based on small-samples learning machine of SVM, we obtain a good performance of less computational load and high recognition rate.

Abstract: In this paper, five kinds of typical multi-core processers are compared from thread, cache, inter-core interconnect and etc. Two kinds of multi-core programming environments and some new programming languages are introduced. Thread-level speculation (TLS) and transactional memory (TM) are introduced to solve the problem of parallelization of sequential program. TLS automatically analyze and speculate the part of sequential process which can be parallel implement, and then automatically generate parallel code. TM systems provide an efficient and easy mechanism for parallel programming on multi-core processors. Typical TM likes TCC, UTM, LogTM, LogTM-SE and SigTM are introduced. Combined the TLS and TM can more effectively improve the sequential program running on the multi-core processors. Typical extended TM systems to support TLS likes TCC, TTM, PTT and STMlite are introduced.

Abstract: Through applying the background values of aquifer derived from fuzzy clustering analysis, a fuzzy comprehensive estimation model was developed for quick recognition of mine water inrush. Based on the hydrological-chemical analysis data of water samples which water bursting sources were known in Liliu mining area, Shanxi province, this paper presented that the hydrological-chemical characters of different aquifer was different, and established a sort of fuzzy comprehensive evaluation models of discriminating coal mine water bursting sources in Liliu mining area. Applied to a production mine, the correct rate of water bursting source judged results by various methods was more than 70%. With the dispersion method and the method extracted from stepwise discrimination analysis to determine the membership degree and Model 3 the type determined by various factors, the correct rate of water bursting source with comprehensive evaluation of combination of two methods was higher respectively 94.5% and 93.3%. The fuzzy system can efficiently and accurately discriminate the resource of water inrush for an unknown sample, and provide the decision basis for the safety production of the coal mine.

Abstract: To improve the accuracy and efficiency of field camera calibration, an improved fast camera calibration method is proposed. Nonlinear translation algorithm based on calibration field is adopted to solve intrinsic parameter while an improved vanishing points method is introduced to get extrinsic parameters. Surveillance camera is used to validate the proposed approach. Experiment results show that the algorithm is convenient and feasible.

Abstract: Accompanied with the release of ARM Cortex micro controller unit (MCU), the development and application of embedded systems in the field of automobile electronics have upgraded to a higher stage. Based on the market requirement for embedded MCU, the characteristics of Cortex-M3 MCU is analyzed and a design of auto GPS navigation system based on Cortex-M3 is given in this paper. The superior performance and implementation of Cortex-M3-based auto embedded system is analyzed and proved from the perspective of code density and program running time.

Abstract: This paper analyzes the Flash Memory interface, SDRAM interface, Ethernet interface and Serial-port expansion circuit. The Embedded Multi-channel Data Acquisition System is designed by MCF5272 microprocessor. The main control system of MCF5272 includes SDRAM, Flash and BDM interface and so on. At the software design, we main introduce the compile and develop of bootload and the compiler and debugging environment of μClinux build. On this base, the general methods and points of the embedded system hardware design were summarized.

Abstract: In this paper an electronic voltage-current voltage transformer (EVCVT) scheme has been proposed based on voltage-current transformation, using the voltage - current transformation technology and weak current detection technology to achieve the accurate measurement of the grid voltage. It transforms the high voltage into low current by high voltage thick film resistor, then the current sensor transforms the low current signal into a standard analog voltage signal, thus an AD converter collects the voltage signal, and the value be imported into the microprocessor for filtration, calibration, coding. After filtering the data would be transmitted to the upper computer or relay protection devices of the digital substation. This paper focused on the design of hardware circuit of digital voltage transformer, developed the software package and produced a prototype control board. Initial experiments show that the scheme is valuable for digital substation.

Abstract: In order to achieve high-accuracy, high speed and low cost A/D conversion, a new design based on STC12C5A32S2 single-chip microcomputer (SCM) is given. Compared with the previous A/D conversion, the biggest advantage is that the paper combine software with hardware and it can adjust the speed of transformation through procedure.We don't need to modify circuit, just need to modify signals of input and procedures. So the flexibility of A/D conversion can be enhanced, also saved costs. The design mainly makes use of new function of STC12C5A32S2 SCM to realize conversion between analog signals and digital signals. In order that researchers can analyze and use the convention results, the design add a LCD display module. The paper primarily analyses the design of circuit and interface technology between the SCM and other chips. Also, the peculiar function of STC, the LCD display method of LMB202DDC and the flow of software are expounded in detail. The simulation result based on Proteus is given by the end of paper.

Abstract: The geomagnetic storm which is caused by the sun's activity is a global natural disaster. For the transformer neutral line connects to the earth directly, the geomagnetic storms can induce GIC in the loop formed by the earth and the transmission lines with long distance. The GIC has very big effect on the safe operation of electric power system when it flows in power grid. It includes the main damages on power system equipment caused by the GIC, the introduction of the GIC generation principle, main features, analysis algorithm and some control measures in this paper. Finally, point out that the GIC of the long distance transmission system and large-scale power grid should be paid more attention.