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A group priority earliest deadline first scheduling algorithm

Frontiers of Computer science 2012年第5期6卷 560-567页

作者： Qi LI Wei BA School of Control Science and Engineering Dalian University of TechnologyDalian 116024China Science and Technology on Underwater Test and Control Laboratory Dalian 116013China

In most priority scheduling algorithms, the num- ber of priority levels is assumed to be unlimited. However, if a task set requires more priority levels than the system can support, several jobs must in practice be assigned the same priority level. To solve this problem, a novel group priority earliest deadline first （GPEDF） scheduling algorithm is pre- sented. In this algorithm, a schedulability test is given to form a job group, in which the jobs can arbitrarily change their or- der without reducing the schedulability. We consider jobs in the group having the same priority level and use shortest job first （SJF） to schedule the jobs in the group to improve the performance of the system. Compared with earliest deadline first （EDF）, best effort （BE）, and group-EDF （gEDF）, simu- lation results show that the new algorithm exhibits the least switching, the shortest average response time, and the fewest required priority levels. It also has a higher success ratio than both EDF and gEDF.

关键词： real-time system group priority success ratio,switching

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Using ambient noise to inverse geo-acoustic parameters

Using ambient noise to inverse geo-acoustic parameters

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2012 International Conference on Advances in Mechanics Engineering, ICAME 2012

作者： Xia, Meng Chun Juan, Li Gui Liang, Zhang Science and technology on Underwater Test and Control Laboratory Dalian 116013 China

ISBN: (纸本)9783037855287

This paper presents a theoretical study of the vertical coherence of ocean ambient noise as the source is the windy ocean surface on the ray theory. At low frequencies less than 2 kHz, the sensitivity of stratified fluid seabed to the vertical coherence of ambient noise in shallow water is analyzed under the condition of distance-irrespective stratified ocean. Using ambient noise data from Chinese north shallow water seabed geo-acoustics parameters are obtained, and the research results show that the inverted method is effective. © (2012) Trans Tech Publications, Switzerland.

关键词： Inverse problems

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The synchronous measurement system of physical flied of the ocean environment based on virtual instrument and ethernet

The synchronous measurement system of physical flied of the ...

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2012 International Applied Mechanics, MechatronicsAutomation and System Simulation Meeting, AMMASS 2012

作者： Liu, Yuelei Science and techology on underwater test and control laboratory Dalian Scientific Test and Control Technology Institute of china Dalian China

In order to acquire the multi-points physical signature of the ocean environment,a distributed measurement system was designed. Because of using virual instrument and ethemet technology, the system can measure the multi-points physical signature *** hardware part of the system contains measurement nodes, central electrical cabinet and measurement *** soft part which modular and open design method is used in is based on LABVIEW developing workbench,achieving the automatic physical measurement, real time display,data processing and management. The experiment results prove the system effective. © (2012) Trans Tech Publications, Switzerland.

关键词： Ethernet

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Tool wear of diamond tools in ultrasonic vibration turning titanium alloys

Tool wear of diamond tools in ultrasonic vibration turning t...

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4th International Conference on Mechanical and Electrical technology, ICMET 2012

作者： Zhimin, Zhou Xiaoyan, Li Quyuanxin Najian Science and Technology on Underwater Test and Control Laboratory Dalian 116013 China College of Life Science and Technology of Dalian University Dalian 116622 China

ISBN: (纸本)9783037855102

Titanium alloys, as difficult-to-cut materials, have poor machinability due to their superior mechanical properties, heat resistance and corrosion resistance. High cutting temperature and great cutting force that will greatly accelerate tool wear often occurs in titanium alloys cutting process. In this paper, an ultrasonic vibration turning method was used to lower diamond tool wear during TC4 titanium alloy turning process. Ultrasonic vibration turning tests were carried out with various cutting parameters. Experimental results indicated that there's a significant reduction of the wear rate of diamond tools by means of ultrasonic vibration in TC4 turning process. For ultrasonic vibration turning, spindle speed, the amplitude and frequency of vibration of the tool are the greatest impact of tool wear, followed by feed rate, then the cutting depth. © (2012) Trans Tech Publications, Switzerland.

关键词： Titanium alloys

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Sea cucumber oriented cyber physical systems

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Ruan Jian Xue Bao/Journal of Software 2013年第SUPPL.1期24卷 41-50页

作者： Du, Xiao-Zhou Jia, Bing Qiao, Jian-Zhong Lin, Shu-Kuan College of Information Science and Engineering Northeastern University Shenyang 110004 China Science and Technology on Underwater Test and Control Laboratory Dalian 116013 China Communication Engineering Design and Research Institute of the General Staff of PLA Shenyang 110005 China

Traditionally, sea cucumber production relies heavily on human labors which results in low production efficiency and inability to meet the demands of a rapidly growing market. To address this problem, this paper brings the idea of cyber physical systems (CPS) into aquatic areas. This paper provide a detailed analysis of the theory and characteristics of CPS along with its practical significance, and construct a physical information fusion system for sea cucumber production. The system is designed according to the CPS architecture, which includes the environmental monitoring subsystem, the information processing and transmission subsystem, the process control subsystem and the remote control center. In accordance with the characteristics of interaction between physics and information, this paper models and verifies the physical process by using the theory of automata, which ensures the reliability of the overall system. The deployment of the main parts of the system has been completed. The observation data indicates that, the system can be used to effectively monitor sea cucumber production. The system also has good scalability. Through in-depth cooperation with experts in the field, we believe it can be extended to be used in many other applications in water environment. © 2013 ISCAS.

关键词： Cyber Physical System

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A study on several feature selection methods in target classification and recognition

A study on several feature selection methods in target class...

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IEEE International Conference on Computer science and Automation Engineering (CSAE)

作者： Yuan, Peng Science and Technology on Underwater Test and Control Laboratory Dalian 116013 China

ISBN: (纸本)9781424487257

In the paper, based on the analysis to several feature selection methods, such as principle component analysis (PCA), maximal gradient selection and exploratory pursuit are presented. First merits and demerits of several methods are compared. Then to true and false underwater target echo signal, Wigner and Burg features are extracted and selected by those methods. Finally, the selected features are trained and recognized by Fuzzy Adaption Resonance Theory (FART) network to compare the effect of several methods to the two kinds of echo signal. The number of training samples to the number of testing samples ratio is 1 to 4. The results show the two kinds of method, maximal gradient selection and exploratory pursuit are not only less computation but also low dimension. The higher recognition can be achieved by the two methods. © 2011 IEEE.

关键词： Feature Selection

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Analysis of infrared character of the temperature stratification sea surface disturbed by the propeller

Analysis of infrared character of the temperature stratifica...

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International Conference on Electronics and Optoelectronics

作者： Liu, Huanying Chen, Shengtao Qi, Yi Wang, Huili Wang, Yunying National Key Laboratory of Science and Technology on Underwater Test and Control Dalian China

ISBN: (纸本)9781612842738

The surface temperature distribution of stratified sea water is different from the surroundings disturbed by the propeller and it can express a particular infrared character. The surface temperature distribution disturbed by a propeller in the negative temperature gradient sea is studied by numerical simulation and infrared imaging. The experiment is carried out through infrared camera imaging and the temperature character of the sea surface is obtained. The results show that there is high comparability between the numerical simulation and the infrared imaging. The mechanism of the sea surface temperature difference is explained and the feasibility of monitoring the sea surface temperature by the infrared camera is also validated. © 2011 IEEE.

关键词： Surface temperature

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Research on the influence and correction method of depth scanning error to the underwater acoustic image measurement

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Chinese Journal of Acoustics 2011年第3期30卷 279-287页

作者： MEI Jidan ZHAI Chunpin WANGYilin HUI Junying Science and Technology on Underwater Acoustic Lab. Harbin Engineering University Harbin 150001 Dalian Scientific Test & Control Technology Institute Dalian 116013

The technology of underwater acoustic image measurement was a passive locating method with high precision in near field. To improve the precision of underwater acoustic image measurement, the influence of the depth scan error was analyzed and the correction method was presented. For a pass array navigation process, when the scan depth was deeper than the real depth of target, the measurement errors could be corrected, and the real depth could be calculated. Otherwise the depth error couldn＇t be corrected. The simulations and the experiments were done. The results were satisfying and consistent with the theoretical conclusions.

关键词：图像测量技术扫描误差校正方法水下定位精度测量误差深度误差纠正

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The Thermal Character of the underwater Heat Exhausting Source

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Journal of Thermal science 2010年第5期19卷 445-450页

作者： Shengtao Chen,Huanying Liu and Yi Qi science and technology on underwater test and control Laboratory,PO Box 67,Dalian,Liaoning 116013 Science and Technology on Underwater Test and Control Laboratory Dalian Liaoning China

The underwater heat exhausting source can cause the thermal difference of the surrounding and surface *** this paper,the thermal character caused by the underwater heat exhausting source is studied by numerical simulation and *** results show that the thermal floating distance is related with the sailing velocity of the underwater *** higher the velocity is,the longer the hot wake is,and the broader the hot scope *** relative distance of the thermal floating spot is almost in a logarithmic law with the *** experimental results are accordant with the numerical simulation,and the obvious hot wake can be observed by the moving underwater heat exhausting source testing with temperature sensors and infrared camera.

关键词： heat exhausting hot wake thermal character underwater target

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Application of support vector machine's parameters selection in echo target recognition

Application of support vector machine's parameters selection...

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IEEE International Conference on Intelligent Computing and Intelligent Systems (ICIS)

作者： Mu, Lin Peng, Yuan Zeng, Yanyan Lin, Zhengqing Zhang, Fengzhen Science and Technology on Underwater Test and Control Laboratory Dalian China

ISBN: (纸本)9781424465835

Evolutionary algorithms for selecting support vector machine (SVM) parameter values which are based on genetic algorithm and particle swarm optimization algorithm are researched in this paper, these algorithms have been successfully applied to the real underwater echo target recognition. Experimental comparison and analysis show that the evolutionary algorithms can identify optimal or near optimal parameter settings more efficient and faster than the traditional "grid-research". Performance of the evolutionary algorithms is demonstrated on the complex underwater echo target character recognition data set. ©2010 IEEE.

关键词： Support vector machines

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