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Direction-of-Arrival Estimation for Improving Resolution Performance of Spatial Spectrum Algorithm SI Wei-jian1, LAN Xiao-yu1, LIU Xue2 Journal of Applied Sciences    2013, 31 (4): 381-386.   DOI: 10.3969/j.issn.0255-8297.2013.04.008 Abstract （1984）      PDF（pc） （4791KB）（1453）       Knowledge map    Save Resolution of the multiple signal classification (MUSIC) algorithm decreases under severe environments such as low SNR, small number of snapshots, and incidence from close angles. To deal with the problem, a modified high-resolution direction-of-arrival (DOA) estimation method is proposed. The algorithm makes full use of information contained in the subspace. By weighting noise subspace with the corresponding revised eigenvalues, a new spatial spectrum is obtained, which is multiplied by the signal subspace projection. By searching the maximum of the spectrum function, the DOAs are obtained. Simulations and experiments confirm that the proposed method can keep high resolution of noise subspace, and improve robustness of the algorithm. Reference | Related Articles | Metrics | Comments（0）

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Evolutionary Computation-based MMI Training in Speech Recognition MAO Xiao-quan, HU Guang-rui, TANG Bin Journal of Applied Sciences    2002, 20 (3): 251-253.   Abstract （604）      PDF（pc） （201KB）（178）       Knowledge map    Save This paper proposes a hybrid MMI/EC architecture to be embedded in the training of HMMs. Each individual in evolutionary computation represents a set of HMMs, while the fitness value of each individual represents the maximum mutual information. Since evolutionary computation is noted for its global search and population-based operations, the globally optimal solutions (or the sub-optimal solutions) can be obtained. Experiments indicate that the system trained with the proposed method is superior to the one trained with the traditional gradient based training method. Related Articles | Metrics | Comments（0）

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THE APPLICATION OF PATTERN RECOGNITION AND LINEAR PROGRAMMING IN THE OPTIMIZATION OF THE REACTION PROCESS OF F-53 TELOMER XU CHI, ZHANG ZHONG, LU JINZHONG Journal of Applied Sciences    1991, 9 (4): 323-328.   Abstract （513）      PDF（pc） （390KB）（97）       Knowledge map    Save The technological condition of the reaction process and the proportion of raw materials of F-53 telomer (IC2F4OC2F4SO4F) were optimized by computerized pattern recognition and linear programming. The target function based on the discriminant introduced from the transformation of multi-dimensional pattern space can determine the optimizational direction and best combination of all factors. Using the optimization method the yield rate increases from 43% to 57.6%. The method has great potentialities for the decrement of the expense of raw materials and that of production cost. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Impact of Relay Location on SER for Amplify-and-Forward Cooperative Communications LI Yun1;2, HUANG Qing1 Journal of Applied Sciences    2012, 30 (5): 479-486.   DOI: 10.3969/j.issn.0255-8297.2012.05.007 Abstract （2542）      PDF（pc） （925KB）（1130）       Knowledge map    Save In this paper, we analyze the symbol error rate (SER) for end-to-end link in amplify-and-forward (AF) cooperative networks. An optimal relay position is made by setting the distance between nodes. A multihop relay selection algorithm based on channel state information (CSI) is proposed, which is the expansion of single-hop relay selection to ensure the lowest SER of the cooperative node. A multi-hop relay selection algorithm based on node position is then investigated according to the impact of node position on system performance. Simulation results indicate that the optimal multi-relay position is at the midpoint between the source and destination nodes, and the multi-hop method provides significant performance gain in terms of total energy over the exiting AF relay selection algorithms. Reference | Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Design and Realization of Harmonic-Suppressed Low-Pass Filter Using Defected Ground Structure Qi Yu-jie;Liu Xue-guan Journal of Applied Sciences    2008, 26 (1): 51-51.   Abstract （2025）            Knowledge map    Save This paper presents a method to use the equivalent-circuit model and 3-D model simulation for the DGS to extract the dimension parameters. Combining an inter-digital elliptic-function low-pass filter with the DGS structure, a novel filter is proposed. A compensated feed-line structure on the side of the inter-digital elliptic-function low-pass filter is designed, and a couple of suitable DGSs are etched under compensated lines. Furthermore, full-wave simulation and optimization of the proposed filter are obtained with HFSS to get better impedance match. The design gives performances of a flat passband, a wide stopband and a compact structure. Agreement between experimental results and measurements shows validity of the DGS filter, which has good harmonic-suppressed characterizes. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

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Paramatric Adaptive Decomposition Based on Gaussian Elementary Functions and Related Adaptive Time-frequency Distribution MA Shi-wei, DEN Jia-mei, CAO Jia-lin Journal of Applied Sciences    2001, 19 (1): 33-36.   Abstract （576）      PDF（pc） （177KB）（180）       Knowledge map    Save We propose a method of adaptive signal decomposition based on the linear frequency modulated Gaussian elementary functions and the related adaptive time-frequency distribution that is positive, cross-term interference free and with better time and frequency resolution. The set of the elementary functions is obtained by the successive matching of the signal local nature with the single prototype Gaussian function through regulating its variance, sweep rate, translation and modulation in an adaptive manner. The matched coefficients and the parameters contain all the information of the signal and can be used for the further processing of the signal. The effectiveness of the method has been proved by simulation results. Related Articles | Metrics | Comments（0）

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Sub-Pixel Edge Detection Based on Spatial Moment and Zernike Moment DING Xing-hao, DENG Shan-xi, YANG Yong-yue, ZHAO Qian-cheng Journal of Applied Sciences    2004, 22 (2): 191-194.   Abstract （512）      PDF（pc） （192KB）（212）       Knowledge map    Save The theories of spatial moment and Zernike moment are presented. An edge model with four parameters has been built and the relations between edge parameters and the two moments are analyzed respectively. The values of edge parameters are calculated to get the edge image. The method can locate edges to sub-pixel. Related Articles | Metrics | Comments（0） Cited: Baidu(37)

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Automatic Tracking of Soil Using Digital Image Correlation WANG Wei1;2, HE Xiao-yuan2, MENG Yun-mei1 Journal of Applied Sciences    2009, 27 (6): 574-579.   Abstract （1605）      PDF（pc） （2391KB）（1469）       Knowledge map    Save In order to explore the dynamic evolution law of soil microstructures in real time, image correlation, matching template and search region adapted to the automatic tracking system are studied towards moving features of soil particles under loadings. It is vital to satisfy the real-time requirement and accuracy performance of the tracking system. By analyzing calculation time, kurtosis and statistical distribution of four types of correlation coefficients, we propose to use the square relation instead of the traditional cubic formula. The rectangular template and search region are used to replace the square template and search region to take advantage of the template’s gray information and meet the real-time requirement. Experimental results show that the automatic tracking system is reliable, which provides an experimental means for the research of continuous deformation in the soil microstructure. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Review of Optofluidic Laser Based Biochemical Sensing WANG Chaoqin, SONG Haoyue, YANG Xi, WANG Yanqiong, GONG Yuan Journal of Applied Sciences    2021, 39 (5): 809-820.   DOI: 10.3969/j.issn.0255-8297.2021.05.007 Abstract （1978）      PDF（pc） （3361KB）（282）       Knowledge map    Save Optofluidic laser has shown great potential in biochemical sensing. Here in this review, we systematically introduced the sensing mechanism and research progress of optofluidic laser based biochemical sensors. The gain medium regulated optofluidic laser sensing mainly depends on the quantity and state of gain molecules. When the biochemical reaction or molecules change the characteristics of microcavity, the resonance condition changes accordingly, and the change can be reflected and read out in the modes, wavelength and emission direction of lasing light. Furthermore, the biochemical molecules can introduce absorption loss and scattering loss in the laser cavity, causing measurable deterioration in laser intensity. Thanks to the amplification of lasing process and optical microcavity, and the narrow linewidth of laser, the laser output characteristics are ultrasensitive to the subtle changes of biochemical process to achieve high sensitivity and high-throughput biochemical sensing. Reference | Related Articles | Metrics | Comments（0）

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Impact of Epidemic on Consumer Economy via Transaction Data PAN Jing, CHAI Hongfeng, QIN Zheng, SUN Quan, GAO Pengfei, ZHENG Jianbin Journal of Applied Sciences    2022, 40 (2): 338-348.   DOI: 10.3969/j.issn.0255-8297.2022.02.015 Abstract （1607）      PDF（pc） （627KB）（123）       Knowledge map    Save The sudden COVID-19 pandemic has led to unprecedented impact on China's economic and social development, especially on consumer economy. Payment is the most closely related economic activity regarding consumers, the data of which can accurately capture the characteristic of the consumer economy. Given the point of view, this paper makes an in-depth exploration in the research direction of payment data. Based on the transaction data from China UnionPay, this paper quantifies the impact of the epidemic on consumer economy and makes a comparative analysis of different provinces and industries. The paper quantitatively reveals that the epidemic progress significantly affects the consumer confidence and the development of consumer economy. According to our analysis, it is unwise to restart work resumption when the epidemic is still not under effective control. From the perspective of payment, this paper profoundly tells about the story of how China fights against the epidemic and puts forward relevant suggestions for the follow-up epidemic prevention and control as well as the comprehensive economic recovery policies. Reference | Related Articles | Metrics | Comments（0）

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GROWTH AND OPTICAL PROPERTIES OF SCINTILLATION CRYSTAL CdWO4 Xu JUN, MA XIAOSHAN, Wu GUANGZHAO, SHEN YAFANG, ZHANG XINMIN, Gu JI Journal of Applied Sciences    1991, 9 (2): 182-184.   Abstract （567）      PDF（pc） （991KB）（95）       Knowledge map    Save Large size crystal CdWO4 has been successfully grown with the CZ method heated by a high-frequency inducing generator. We find that the oxygen vacancy and Fe3+ impurities are the main reasons for crystal colouration. The luminescence spectra of crystal CdWO4 have also been measured. Related Articles | Metrics | Comments（0）

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DETERMINATION OF THE PULSE WIDTH OF PULSED MAGNETIZING FIELD FOR A RARE EARTH MAGNET WITH HIGH COERCIVE FORCE FU ZHIYU, XU MEIJIE Journal of Applied Sciences    1993, 11 (2): 131-135.   Abstract （386）      PDF（pc） （370KB）（82）       Knowledge map    Save An effective device which can generate the pulsed magnetizing field is shown. The approximate expression for the pulsed magnetizing field is derived, and its pulse width and peak intensity related to the circuit elements are given. A reasonable physical model which describes the magnetization process and involves the magnetic hysteresis and eddy current is presented, and the numerical computation is made. The pulse field widths which are required to magnetize the specific magnets are determined, and the useful design parameters are obtained. Related Articles | Metrics | Comments（0）

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Lossless Data Hiding in Palette Images Based on Mix-ary Codes LÜ Jin-peng, LIANG Hai-hua, ZHANG Xin-peng Journal of Applied Sciences    2015, 33 (6): 637-643.   DOI: 10.3969/j.issn.0255-8297.2015.06.007 Abstract （1279）      PDF（pc） （9501KB）（560）       Knowledge map    Save This paper proposes a lossless data hiding method in palette images based on mix-ary codes. According to the distributionof indices, the indices are divided into effective indices and redundant indices. In the palette a certain number of redundant indices are mapped to the color of an effective index. Then the indices mapping to the same color stand for different secret digits in order to embed extra data losslessly. A dynamic programming algorithm is used to find the best allocation for redundant indices to achieve the highest embedding capacity. Embedded data subsets carried by different colors are different notational sequences. The data embedding operation does not affect the original image.Experiments showthat themethod has higher embedding capacity than previous methods, especially for medical images. Reference | Related Articles | Metrics | Comments（0）

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STUDIES ONN PASSIVATING A P2S5/NH4OH-TREATED GaAs SURFACE ZONG XIANGFU, WENG YUMIN, LID KEIFENG, FAN ZHINENG, LI CHAN, PAN ZONGWEI Journal of Applied Sciences    1994, 12 (3): 196-202.   Abstract （586）      PDF（pc） （407KB）（106）       Knowledge map    Save The effect of P2S5/NH4OH treatment on the (100) surface of GaAs was studied by X-ray photoelectron spectroscopy (XPS),Auger electron spectroscopy (AES) and photoluminescence (PL).The results show that after passivation the native oxide of GaAs Surface is completely removed and a passivation layer mainly composed of As-Sand Ga-Sbonds forms on the sample surface,and prevents the adsorption of oxygen. This concluson has been supported by results of PL experiments.The PL intensity and its contrast obtained on GaAs surface depend on the surface recombination and they are controlled by passivation. The results of PL experiments show the reduction of surface recombination and of the density of surface states P2S5/NH4OH treatment is more stable than the others,such as Na2S. Related Articles | Metrics | Comments（0）

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Hybrid Memory Scheme for Genetic Algorithm in Dynamic Environments CHEN Hao1, LI Ming2, CHEN Xi2 Journal of Applied Sciences    2010, 28 (5): 540-545.   DOI: 10.3969/j.issn.0255-8297.2010.05.015 Abstract （1906）      PDF（pc） （577KB）（1682）       Knowledge map    Save In order to effectively solve dynamic optimization problems, a new hybrid memory scheme that consists of short-term memory and long-term memory is proposed. Information to be memorized includes the best individual and the probability vector of current population. Information of short-term memory is extracted to build the next population in each generation. Long-term memory is assigned for the short-term memory when a environmental change is detected. A new genetic algorithm is thus constructed based on the hybrid memory. Performance of the algorithm is verified in different environments including non-cyclic, cyclic, and cyclic with noise. Computation results indicate that this algorithm is superior to similar algorithms in dealing with dynamic optimization problems. Related Articles | Metrics | Comments（0） Cited: Baidu(7)

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Optimal Design and Sensitivity Analysis of Double-Diaphragm Structure FBG Soil Pressure Sensors XING Guangzhi, CHEN Bozhi, WU Wenjing Journal of Applied Sciences    2024, 42 (2): 248-261.   DOI: 10.3969/j.issn.0255-8297.2024.02.006 Abstract （186）      PDF（pc） （3541KB）（107）       Knowledge map    Save In order to realize the health monitoring and effective evaluation of the pile foundation structure safety and its service state, a double-diaphragm structure soil pressure sensor is proposed in this paper. Fiber Bragg gratings (FBGs) are used as the sensing element. By adding a temperature compensation film in the protective structure, complete separation of temperature effects and external load impacts is achieved. Based on the working principle of a double-diaphragm structure soil pressure sensor, the pressure sensitivity coefficient characteristics of the sensor are discussed. A systematic analysis is conducted on the influencing parameters of sensitivity coefficient by combining finite element analysis and experimental research. Numerical analysis results show that the thickness of the membrane has the greatest impact on the pressure sensitivity coefficient. The structural radius and membrane thickness can be set as 20 mm and 1.8 mm, respectively. Experimental results show that within the range of 0~2 MPa, the pressure sensitivity coefficient reaches 3.32 pm/kPa. Reference | Related Articles | Metrics | Comments（0）

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Protected Wildlife Monitoring System with Low Power Consumption Based on NB-IoT ZHANG Ximin, ZHAN Haisheng, LIU Qiang, YUAN Zhanjun, ZHANG Jinbo Journal of Applied Sciences    2023, 41 (2): 262-271.   DOI: 10.3969/j.issn.0255-8297.2023.02.007 Abstract （2259）      PDF（pc） （10189KB）（431）       Knowledge map    Save A distributed protected wildlife tracking and monitoring system based on NBIoT is proposed to realize low power consumption, remote monitoring, customization and low cost. The key solutions including efficient power management, concurrent communication processing, and network transparent transmission are given. The system consists of trackers and a monitoring information system. Each tracker includes a NB-IoT communication and location module, a low-power microcontroller, a solar composite power supply component with lithium battery, and a high-efficiency power converter. The monitoring information system is composed of data communication equipment, server and monitoring terminals. Experiments show that the system can collect the position of wild animals remotely and display their real-time positions and activity trajectories on the WEB map. Customized statistical analysis of the data and reports can be generated. The average power consumption of the tracker is less than 50mW, and the average positioning error is less than 20 meters. The system has a large monitoring range and low cost, and has been applied in a wildlife protection station showing good performance. Reference | Related Articles | Metrics | Comments（0）

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Parallel Optimization of Chinese Language Model Based on Recurrent Neural Network WANG Long1,2, YANG Jun-an1,2, CHEN Lei1,2, LIN Wei3, LIU Hui1,2 Journal of Applied Sciences    2015, 33 (3): 253-261.   DOI: 10.3969/j.issn.0255-8297.2015.03.004 Abstract （2049）      PDF（pc） （2539KB）（2607）       Knowledge map    Save  High computational complexity leads to low efficiency in training a recurrent neural network (RNN) language model. This becomes a major bottleneck in practical applications. To deal with this problem, this paper proposes a parallel optimization algorithm to speed up matrix and vector operations by taking the advantage of GPU’s computational capability. The optimized network can handle multiple data streams in parallel and train several sentence samples simultaneously so that the training process is significantly accelerated. Experimental results show that the model training of RNN is speeded up effectively without noticeable sacrifice of model performance. The algorithm is verified in an actual Chinese speech recognition system. Reference | Related Articles | Metrics | Comments（0） Cited: Baidu(3)

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Wireless Temperature Control System for High Temperature Heating Furnace Based on PFC-PID Algorithm LIU Yangyi, SU Chengli, SHI Huiyuan, LI Ping, BO Guihua Journal of Applied Sciences    2019, 37 (6): 875-886.   DOI: 10.3969/j.issn.0255-8297.2019.06.012 Abstract （1142）      PDF（pc） （8664KB）（192）       Knowledge map    Save Address to the complicacy and difficulty of wiring installation for wired process control in harsh industrial site environment, this paper develops a wireless temperature control system for high temperature heating furnace based on predictive functional control-proportion integration differentiation (PFC-PID). First, a wireless communication network based on WirelessHart protocol is built to replace the traditional wired network. The wireless network uses the monitor and control generated system (MCGS) configuration software as application platform to measure and analyze the industrial high-temperature heating furnace. Then the wireless temperature control system is developed by integrating the improved predictive functional control (PFC) with the traditional proportion integration differentiation (PID), to realize wireless monitoring and real-time control of the temperature of the heating furnace. The results of engineering implementation show that the designed control system can solve the problem of packet loss in the wireless communication process. It works with satisfied reliability, control accuracy and response speed required in industrial sites. The designed system can also solve the problems of low scalability and poor mobility of wired network effectively. Reference | Related Articles | Metrics | Comments（0）

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Energy-Efficient Distributed Relay Selection Based on Statistical Channel State Information JIANG Hai-fang, ZHANG Si-hai, ZHOU Wu-yang Journal of Applied Sciences    2012, 30 (3): 221-226.   DOI: 10.3969/j.issn.0255-8297.2012.03.001 Abstract （1691）      PDF（pc） （742KB）（1289）       Knowledge map    Save In this paper, we propose a distributed relay selection algorithm based on statistical channel state information (CSI) in amplify-and-forward (AF) cooperative networks. A tradeoff is made between energy efficiency and system outage performance. A forwarding threshold is obtained by minimizing the average total power consumption. Each relay individually decides whether to participate in forwarding the source signals according to a forwarding threshold. A distributed multiple relay selection (DMRS) algorithm is proposed, in which all candidate relays have the possibility of forwarding the signals and the threshold is obtained by numerical search. The DMRS algorithm obtains good outage performance with low power consumption. A distributed single relay selection (DSRS) algorithm with low complexity is then investigated under the assumption that only one relay forwards the signals. Simulation results indicate that the proposed algorithms provide significant performance gain in terms of energy efficiency over the existing AF relay selection algorithms. Related Articles | Metrics | Comments（0） Cited: Baidu(2)