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Application of A* Algorithm for real-time Path Re-planning of an Unmanned Surface Vehicle Avoiding Underwater Obstacles

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Journal of Marine Science and Application 2014年第1期13卷 105-116页

作者： Thanapong Phanthong Toshihiro Maki Tamaki Ura Takashi Sakamaki Pattara Aiyarak Department of Physics Faculty of Science Prince of Songkla University Institute of Industrial Science the University of Tokyo 4-6-1 Komaba Meguro-ku Tokyo 153-8505 Japan Department of Computer Science Faculty of Science Prince of Songkla University

This paper describes path re-planning techniques and underwater obstacle avoidance for unmanned surface vehicle(USV) based on multi-beam forward looking sonar(FLS). Near-optimal paths in static and dynamic environments with underwater obstacles are computed using a numerical solution procedure based on an A* algorithm. The USV is modeled with a circular shape in 2 degrees of freedom(surge and yaw). In this paper, two-dimensional(2-D) underwater obstacle avoidance and the robust real-time path re-planning technique for actual USV using multi-beam FLS are developed. Our real-time path re-planning algorithm has been tested to regenerate the optimal path for several updated frames in the field of view of the sonar with a proper update frequency of the FLS. The performance of the proposed method was verified through simulations, and sea experiments. For simulations, the USV model can avoid both a single stationary obstacle, multiple stationary obstacles and moving obstacles with the near-optimal trajectory that are performed both in the vehicle and the world reference frame. For sea experiments, the proposed method for an underwater obstacle avoidance system is implemented with a USV test platform. The actual USV is automatically controlled and succeeded in its real-time avoidance against the stationary undersea obstacle in the field of view of the FLS together with the Global Positioning System(GPS) of the USV.

关键词： underwater obstacle avoidance real-time pathre-planning A* algorithm sonar image unmanned surface vehicle

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Impact of the real-time Bus Information on Bus Riders, an Evidence from Guangzhou

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Journal of Harbin Institute of Technology(New Series) 2019年第4期26卷 41-49页

作者： Jianrong Liu Jiajun Mei School of Civil Engineering and Transportation South China University of Technology

This paper evaluates impacts of the real-time information from the smartphone APP and the real-time information board at bus stops on bus users with survey data. Through the analysis of data with t-test and linear regression, it is found that the waiting time of bus riders with real-time information from the smartphone APP is much less than that of bus riders without the real-time information. As to the perceived waiting time of bus users, through the linear regression, the study finds that without the real-time information, bus riders’ perceived waiting time is greater than waiting time. At the same time, the perceived waiting time of bus users with real-time information is only slightly larger than their waiting time. Through regressing anxiety on real-time information, perceived waiting time and so on, it is found that real-time information reduces anxiety remarkably.

关键词： real-time information bus perceived waiting time waiting time anxiety

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SPACEBORNE SAR real-time ECHO SIMULATION PLATFORM BASED ON VPX

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Journal of Electronics(China) 2014年第3期31卷 193-199页

作者： Ni Chao Hu Xiao Zhang Zhimin Zhao Fengjun Institute of Electronics Chinese Academy of Sciences University of Chinese Academy of Sciences

To perform the ground test of a spaceborne Synthetic Aperture Radar(SAR) system, an echo simulator with the characteristics of multimode, multi-assemblage, and real time is proposed in this paper. A hardware platform of the real-time echo simulator based on the VPX bus is designed. With this platform, real-time multi-point echo generation and scenario targets echo generation can be achieved by the real-time signal processing in Field Programmable Gate Array(FPGA), utilizing the parameters calculated by the industry computers. Furthermore, this platform can output different signals if it is expanded to multi-channels, making it possible for the assignment of echo generation and test in different spaceborne SAR modes. The test results with the actual SAR system show that this platform can satisfy the system requirements and is now used in practice.

关键词： Synthetic Aperture Radar(SAR) Echo simulation real-time VPX bus

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real-time Upstream Services Demonstration in Orthogonal Frequency Division Multiplexing- Passive Optical Network System

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China Communications 2014年第1期11卷 26-33页

作者： LI Ming Andrey Lukyanenko Sasu Tarkoma Antti Yl-Jski Department of Computer Science and Engineering Aalto University Department of Computer Science University of Helsinki

Abstract： real-time digital service and mul- timedia service upstream transmission in Dig- ital Signal Processing （DSP）-based Orthogo- nal Frequency Division Multiplexing-Passive Optical Network （OFDM-PON） is experimen- tally demonstrated with Centralised Light Sou- rce （CLS） configuration in this paper. After transmitted over 25 km Standard Single Mode Fibre （SSMF） with -16.5 dBm optical power at receiver, the Bit Error Rate （BER） is 9.5 ×10^-11. The implementations of digital domain up-conversion and down-conversion based on Field Programmable Gate Array （FPGA） are int- roduced, which can reduce the cost of In-ph- ase and Quadrature （IQ） radio frequency mix- ers utilised at transmitter and receiver. A car- rier synchronization algorithm is implemented for compensating carrier offset. A channel eq- ualization algorithm is adopted for compen- sating the damage of channel. A new structure of Frequency Synchronization Unit （FSU） des- igned in FPGA is also proposed to cope with the frequency shifting at receiver.

关键词： orthogonal frequency division multiplexing-passive optical network real-time field programmable gate array wavelength division multiplexing-OFDM-PON frequency synchronization

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Fault-Tolerant Rate-Monotonic Compact-Factor-Driven Scheduling in Hard-real-time Systems

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Wuhan University Journal of Natural Sciences 2010年第3期15卷 217-221页

作者： ZHU Ping YANG Fumin TU Gang School of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 Hubei China

Considering the disadvantage of first-fit strategy in fault-tolerant rate-monotonic first-fit （FTRMFF） algorithm, we analyze the slack time of processors and the schedulability of periodic tasks in rate-monotonic （RM） algorithm. Then, the RM-based idleness factor and compact factor are presented to quantify the compact degree of tasks assigned to the same processor. In this paper, the novel fault-tolerant rate-monotonic compact-factor-driven （FTRMCFD） algorithm, which follows the principle of compact factor maximal when allocating the processors for tasks, is proposed. FTRMCFD algorithm makes every processor contain more tasks and get higher utilization to increase the schedulability performance of distributed systems. The simulation experiments reveal that FTRMCFD can reduce the number of required processors by up to 11.5% （with an average of 5.3%）.

关键词： fault-tolerant real-time rate-monotonic scheduling

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基于DNA扣除法的real-time RT-PCR对工程乳酸菌外源基因表达的绝对定量分析

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生物工程学报 2009年第8期25卷 1240-1246页

作者：史瑞刘飞霍贵成杨丽杰东北农业大学乳品科学教育部重点实验室哈尔滨150030

本研究旨在利用real-time RT-PCR对外源基因在工程乳酸菌中的表达进行定量分析,建立一种新的real-time RT-PCR分析方法。采用玻璃珠热酚法提取工程乳酸菌总RNA,对外源目的基因的反转录(含有cDNA和DNA)样品和非反转录(仅含DNA)样品进行Re... 详细信息

本研究旨在利用real-time RT-PCR对外源基因在工程乳酸菌中的表达进行定量分析,建立一种新的real-time RT-PCR分析方法。采用玻璃珠热酚法提取工程乳酸菌总RNA,对外源目的基因的反转录(含有cDNA和DNA)样品和非反转录(仅含DNA)样品进行real-time PCR检测,根据经典绝对定量方法并结合DNA扣除法进行分析,将得到的Ct值通过标准曲线换算为样品拷贝数,通过从反转录样品中扣除DNA样品的拷贝数的量,去除了DNA对实验结果的影响,得出最终的定量结果。采用以上方法分析工程乳酸乳球菌NZ9000中外源纤维素酶基因CBHⅡ的表达情况,对表达量较低的目的基因进行转录水平的分析,避免了RNA的损失,得到了外源基因表达的量为(1.28±0.02)×10-1 copies/cfu。这种基于DNA扣除法的real-time RT-PCR绝对定量方法可以有效地对外源基因在工程乳酸菌中的表达进行分析。

关键词：乳酸菌 real-time RT-PCR 绝对定量 DNA扣除法

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The Multi-level Recovery of Main-memory real-time Database Systems with ECBH

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The Journal of China Universities of Posts and Telecommunications 2003年第1期10卷 15-24页

作者： ZOU Yong-gui, GE Jun-wei (College of Computer Science and Technology, Chonqqing University of Posts and Telecommunications, Chongqing 400065, P.R. China) College of Computer Science and Technology Chonqqing University of Posts and Telecommunications 重庆 400065

Storing the whole database in the main-memory is a common method to processreal-time transaction in real-time database systems. The recovery mechanism of Main-memory real-timeDatabase Systems (MMRTDBS) should reflect the characteristics of the main-memory database andreal-time database because their structures are quite different from other conventional databasesystems. In this paper, therefore, we propose a multi-level recovery mechanism for main-memoryreal-time database systems with Extendable Chained Bucket Hashing (ECBH). Owing to the occurrence ofreal-time data in real-time systems, we should also consider it in our recovery mechanism .According to our performance test, this mechanism can improve the transaction concurrency, reducingtransactions ' deadline missing rate.

关键词： DBMS multi-level recovery hash main- memory database real-time

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real-time monitoring system for quality monitoring of jujube slice during drying process

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International Journal of Agricultural and Biological Engineering 2022年第3期15卷 234-241页

作者： Yuxue Cao Xuedong Yao Yongzhen Zang Yubao Niu Hongwei Xiao Huan Liu Rongguang Zhu Xia Zheng Qiang Wang Xiangnan Zhang Shiyu Wei College of Mechanical and Electrical Engineering Shihezi UniversityShihezi 832000XinjiangChina Key Laboratory of Northwest Agricultural Equipment Ministry of Agriculture and Rural AffairsShihezi 832000XinjiangChina Key Laboratory of Modern Agricultural Machinery Corps Shihezi 832000XinjiangChina College of Engineering China Agricultural UniversityBeijing 100083China College of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China

The real-time monitoring and prediction system for quality attributes of jujube slices during the drying process was designed to solve the problem of destructive and inconvenient of the traditional quality detection method and realize quality online ***,machine vision and automatic weighing were employed to monitor the color and moisture content changes of jujube slices in ***,correlation models between color parameter(a^(*)value)and nutritional quality attributes(vitamin C,reducing sugar)were established to predict vitamin C and reducing sugar content of jujube slices during the drying ***,the upper computer monitoring software was integrated and designed based on LABVIEW virtual instrument,and the real-time monitoring system was tested and *** showed that:the changing trends of color(L^(*),a^(*),and b^(*)values)monitored by the system were basically the same as the results detected by color difference meter,and the average errors of L^(*),a^(*),and b^(*)values were 0.93,0.52,and 0.73,*** average relative error of moisture content between the system monitoring and manual static detection was 0.18%.The average error of vitamin C and reducing sugar content between the system prediction and manual detection were 50 mg/100 g in dry basis and 0.71g/100 g in dry basis,*** current work can provide a useful reference for real-time monitoring of quality attributes of fruits and vegetables during the drying process.

关键词： jujube slice quality attributes real-time monitoring system drying process

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SRDAAR－QNPP：a computer code system for the real－time dose assessment of an accident release for Qinshan Nuclear Power Plant

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Journal of Environmental Sciences 1994年第3期6卷 296-309页

作者： Hu Erbang Wang Han(China Institute for Radiation Protection, Taiyuan 030006, China)

The paper presents a computer code system 'SRDAAR- QNPP' for the real-time dose as-sessment of an accident release for Qinshan Nuclear Power Plant. It includes three parts:thereal-time data acquisition system, assessment computer. and the assessment operating code system. InSRDAAR-QNPP, the wind field of the surface and the lower levels are determined hourly by using amass consistent three-dimension diasnosis model with the topographic following coordinate system.A Lagrangin Puff model under changing meteorological condition is adopted for atmosphericdispersion, the correction for dry and wet depositions. physical decay and partial plume penetrationof the top inversion and the deviation of plume axis caused by complex terrain have been taken in-to account. The calculation domain areas include three square grid areas with the sideline 10 km, 40krn and 160 km and a grid interval 0.5 km, 2.0 km, 8.0 km respectively. Three exposure pathwaysare taken into account:the external exposure from immersion cloud and passing puff, the internalexposure from inhalation and the external exposure from contaminated ground. This system is ableto provide the results of concentration and dose distributions within 10 minutes after the data havebeen inputed.

关键词： real-time dose assessment computer code system nuclear power plant accident.

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土壤中烟草根黑腐病菌的real-time PCR分子检测

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中国烟草学报 2019年第2期25卷 130-134页

作者：许大凤叶磊张丽娜韩永镜周本国檀根甲安徽省农业科学院烟草研究所安徽合肥230031 安徽农业大学安徽合肥230036 安徽省烟草公司安徽合肥230022

根据烟草根黑腐菌与其它近缘真菌在ITS序列上的差异,设计PCR检测引物TbF/TbR,并通过对各菌株基因组DNA扩增验证其特异性;以接种10倍浓度梯度的根黑腐菌孢子的土壤DNA为模板,建立土壤烟草根黑腐菌real-time PCR检测的标准曲线,得出每个... 详细信息

根据烟草根黑腐菌与其它近缘真菌在ITS序列上的差异,设计PCR检测引物TbF/TbR,并通过对各菌株基因组DNA扩增验证其特异性;以接种10倍浓度梯度的根黑腐菌孢子的土壤DNA为模板,建立土壤烟草根黑腐菌real-time PCR检测的标准曲线,得出每个反应体系中分生孢子数目的对数(x)和对应的Ct值(y)之间呈线性关系:y=-1.5373x+24.955,R2=0.9909(P<0.01)。通过对5块烟田土壤烟草根黑腐菌检测和烟田烟草根黑腐病的调查,证实上述方法可以准确检测土壤中烟草根黑腐菌孢子数量。

关键词：烟草根黑腐病 rDNA-ITS real-time PCR

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