Applied Mechanics and Materials Vols. 241-244

Abstract: One hundred and thirty-seven samples of agricultural residue were taken from the study area of forty subdistricts in twenty districts of ten provines in the Northeastern region of Thailand. The samples were analyzed for major physical and chemical properties and subjected to simulated burning. Rice straw had the highest dry weight and bagasse the lowest. Bagasse had the highest moisture content and the highest carbon content. Results from simulated burning found that sugarcane leaf emitted more CO₂ than the other residues. Weight loss on combustion was in the range of 75-92 %, and the simulated burn of agricultural residues showed CO₂ emission values at 67% of the IPCC values.

Abstract: A new measurement system was developed to characterize the physical compression properties of textile materials based on the mechanical device, microelectronics, sensors and control system. Derived from the typical pressure-displacement curve and test data, three indices were defined to characterize the compression performance of textile materials. The measurement principle and the evaluation method for compression properties of textile materials were introduced. Twelve types of fabrics with different structural features and made from different textile materials were tested. The one-way ANOVA analysis was carried out to identify the significance of the differences of the evaluation indices among the fabrics. The results show that each index is significantly different (P<0.05) among different fabrics.

Abstract: To measure the grain moisture content with time-domain transmission technology (TDT), electromagnetic wave propagation characteristics was studied to find the relationship of electromagnetic wave propagation and the dielectric parameters of grain. Basic structure of measurement sensor was designed to be coaxial transmission line based on TDT theories. The main parameters of the sensor were calculated. The measurement circuit was designed based on processing theories of high frequency electromagnetic signals. Grain samples with different moisture contents were measured by both TDT system and the standard drying method. The results show that TDT system with Quadratic curve measurement model is of desired measurement accuracy.

Abstract: Energy meters have become smart and functionally powerful over time. Still many concerns about the correctness of their behavior are raised by society and the effort involved on new smart meters type approval are growing huge. Aiming at establishing trust on the smart meter, this paper proposes a consumption authenticator which can be read from the meter's display and verifiable by the user. This authenticator is generated inside a secure device, placed on the metering module, using ECPVS signature scheme providing partial message recovery. Since our approach considers different Time-Of-Use scenarios, a composing technique for the authenticator's embedded message is presented. Our concerns are the necessary data for validating Time-Of-Use rates measurement values and the final size of the message.

Abstract: In order to measure the magnetic field around electronic products, household appliances and industrial electrical equipment, this paper puts forward a new method which makes use of electromagnetic coupling design based on three-axis electromagnetic leakage. This method can overcome the disadvantage of traditional single-axis measurement which needs to get the total magnetic field after several times’ measurement. This paper designs three-axis electromagnetic leakage detector for circuit measurement, which is proved to be correct after circuit measurement experiment. It can easily detect 30-2K Hz leakage magnetic field of low frequency generated from electrical appliances products.Introduction.

Abstract: Based on GaN HEMT the monolithic microwave power amplifier (MMIC) with great advantages of high operating voltage, high output power, wide frequency bandwidth and small features loss has been widely used in phased-array radar, aerospace, missile interception system. However, MMIC test has many disadvantages, such as, including many microwave instruments, test process is complex, manual operate lots of instruments, and write down test data, result in slowed down test process. In the paper, it introduces a new system by ourselves. This can simplify the MMIC test process, and free ourselves from heavy test task, and focus the performance of circuit. It realizes the automatic test and proves it using a based on GaN HEMT 2×4 MMIC circuit.

Abstract: Aiming to solve the problems of long execution count and low frequency of counter which has been largely used in various electronic facilities and PLCs, unlike traditional design that utilize embedded microprocessor software for count operation, this paper proposed a parallel operated counter based on ARM+FPGA. The FPGA counter module consists of count controller, SDRAM dynamic parameter and soft contact state register, the count controller carries out counter operation for timing unit every 1ms, then results from count operation would be saved in counter parameter list of a dual port RAM, when controller commands need to be executed via ARM, the counter will be used as a regular memory unit for W/R operation, thus no executing time would be spared basically, which can well meet the system requirements where large number of controllers are needed. Simultaneously, principles of system composition, count operation control and count operation flow are all introduced followed by which a field test is also carried out for testament of the designed counter system.

Abstract: Digital filter technology is quite important in the signal processing field. This paper realizes digital filter designing by way of the virtual instrument technology, and this paper introduces the filter plat front panel and program frame diagram designing based on the FIR filter algorithm through the LabVIEW platform. Through the simulation, the virtual digital filter validates the designing accuracy. The digital filter achieves the ideal effect in filtering, which can be widely applied into the signal processing field, such as digital de-nosing, and experimental study, etc. Digital filter panel designing has broad application prospect and research value.

Abstract: In this paper, texture analysis was used to discriminate digital chest radiographs of pneumoconiosis patients from normal ones. First, lung fields in each chest radiograph were segmented by using the morphological reconstruction and Otsu-thresholding. Second, several texture features based on the histogram and co-occurrence matrix of grey levels were extracted. Finally, a neural network based classifier was trained with features extracted from 66 chest images to distinguish pneumoconiosis patients from normal cases. Another 29 images were used to assess the diagnosis performance of the classifier, giving an overall accuracy of 79.3%.

Abstract: This paper probes into the design of greenhouse environment monitoring system based on S3C2410 ARM microprocessor. It focuses on the development of Graphical User Interface (GUI) applications based on Qt/Embedded and the Linux driver for temperature and humidity sensor in the environment monitoring system. The use of GSM module achieves the safe warning function. By porting Web server and using CGI technology, the system realizes the remote monitoring well. The test results show that the system can accurately capture and display temperature, humidity and light intensity of the greenhouse, provides a friendly human-computer interface, is easy to use and has good application prospects.