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Modelling of communication delays in wireless networks

Modelling of communication delays in wireless networks

13th IMEKO TC10 Workshop on Technical Diagnostics 2014: Advanced measurement Tools in Technical Diagnostics for Systems' Reliability and Safety

作者： Krupanek, Beata Bogacz, Ryszard Faculty of Electrical Engineering Institute of Measurement Science Electronics and Control Silesian University of Technology Akademicka 10 44-100 Gliwice Poland

ISBN: (纸本)9781632669841

The paper presents a new conception of building probabilistic models of communication delays in wireless networks that basis on using a delta function sequence to describe retransmissions between a transmitter and a receiver. It is assumed that the access time of the transmitter is described by a probability density function and the communication channel established in the wireless medium is disturbed by passive or active factors which cause that the transmission can be not correct and the sent data have to be retransmitted. Theoretical considerations have been verified by measurement results obtained by using the experimental system developed for investigating delays caused by external disturbances influencing the wireless transmission. A method of identification of the proposed model parameters and verification of the identified values has been presented. Copyright© (2014) by the International measurement Confederation (IMEKO).

关键词： Transmitters

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Chaos characteristics analysis of transient signals for phase-locked synthesizer based FHC system 14

Chaos characteristics analysis of transient signals for phas...

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14th International Symposium on communications and Information Technologies, ISCIT 2014

作者： Ping, Li Guohong, Wang Yan, Xiaopeng Peng, Gong Shi, Wenbo Chunyun, Song Beijing Institute of Technology National Key Lab. of Mechatronic Engineering and Control Beijing100081 China Northeastern University School of Computer and Communication Engineering Qinhuangdao China National Lab. of Information Control Technology for Communication System Jiaxing Zhejiang314033 China

ISBN: (纸本)9781479944163

Frequency synthesizer plays an important role in frequency hopping communication system. In this paper, we derivate the conditions for a system to become the chaotic based on the phase model of phase-locked synthesizer. We found that the system parameter changing during the frequency switching is able to make the system to be chaotic. Based on the Cao's method [5], we find that the fractal dimension of the transient signals should be equal to or less than 4, which also provides the maximal positive Lyapunov exponent. In addition, the unique double-ring attractor of them is also reproduced through the phase reconstruction, which also implies that the frequency switching will result in a chaotic for Frequency-Hopping communication system. © 2014 IEEE.

关键词： Fractal dimension

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Research on a liquid color detecting device

Research on a liquid color detecting device

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2014 International Conference on Electronic engineering and Information Science, ICEEIS 2014

作者： Zhou, Zhen Li, Di Xing Qin, Yong Liu, Li Feng School of Measurement and Communication Engineering Harbin University of Science and Technology HeiLongJiang Harbin 150080 China The Higher Educational Key Laboratory on Measuring and Control Technology Instrumentations of Heilongjiang Province HeiLongJiang Harbin 150080 China

ISBN: (纸本)9783038351467

At present, the error rate of color detecting device is generally between 1%-5%, and mainly for the solids. To improve the detection accuracy further, and adapt liquid color detection, this research uses a new method to build light paths, and combines the United States TAOS's TCS3200 color sensor and STM32 microcontroller. A new type of liquid color detecting device is designed, system structure and testing process of the device are also given. This device has more than 10-bit A/D conversion accuracy, 0.5% or less error rate, and less than 30% of the price of similar products. It has broad promotion and application prospects, and can be widely used in chemistry, biology, grain and other fields. © (2014) Trans Tech Publications, Switzerland.

关键词： Color

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Stepped-frequency radar imaging algorithm based on compression sensing

Stepped-frequency radar imaging algorithm based on compressi...

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International Conference on Vehicle and Mechanical engineering and Information technology, VMEIT 2014

作者： Huang, Lu Wang, Peng Yu Song, Qian Laboratory of Measurement and Control Equipment Beijing Institute of Tracking and Telecommunications Technology BITTT Beijing China College of Electronic Science and Engineering National University of Defense Technology NUDT Changsha China

ISBN: (纸本)9783038350606

Compressive sensing (CS) theory asserts that one can recover original signals from far fewer random samples under the condition of being sparse. CS theory is applied to high resolution imaging of vehicle-mounted stepped-frequency forward-looking ground-penetrating radar. This paper explores an approach of obtaining discrete scattering structure of the metal mine based on CS imaging and extracting geometry parameters to discriminate targets. Real data of vehicle-mounted stepped-frequency forward-looking ground-penetrating radar is processed. High resolution images of the metal mine with double-scattering structure are obtained. The feasibility of the method is tested through these images. © (2014) Trans Tech Publications, Switzerland.

关键词： Compressed sensing

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Scalable load balancing for large-scale web server clusters

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Journal of Computational Information Systems 2014年第13期10卷 5763-5771页

作者： Huang, Chuibi Wang, Jinlin Wu, Gang Chen, Jun Department of Automation University of Science and Technology of China Key Laboratory of Network Communication System and Control Hefei China Institute of Acoustics Chinese Academy of Sciences National Network New Media Engineering Research Center Beijing China

Load balancing is a fundamental technology to provide scalability for web server clusters. But in the scenarios where the web server clusters have massive amount of user accesses, a single load balancing server is unable to carry the user visits. Therefore load balancing tasks should be undertaken among a set of load balancing servers. Correspondingly the loads among these servers also need to be balanced. In this paper, we proposed a load balancing scheme that could provide scalability, availability and reliability for large-scale web server clusters. The scheme combines existing routing techniques and splits the function of load balancing into three levels that could be implemented by different devices, thereby enabling the web server cluster scales with user accesses. The experiment results have demonstrated the effectiveness of the program. © 2014 by Binary Information Press

关键词： Scalability

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Study of the Application of LOPA in Risk Assessment of Multi-initiating Events

Study of the Application of LOPA in Risk Assessment of Multi...

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International Conference on Instrumentation, measurement, Computer, communication and control (IMCCC)

作者： Lan Ma Yongqing Jiang Chen Liang Zhengmei Liu School of Measurement-Control & Communication Engineering Harbin University of Science and Technology Harbin China

ISBN: (纸本)9781479965762

There are some defects when dealing some types of complex accident scenes which using LOPA as the strict definition of independent protection layer limits its application scope. The purpose of this paper is aimed at the accident scenarios where multi-initiating event trigger a single accident consequence, putting forward strategy of selecting the aggregation method and the maximum screening method, so that the effectiveness of LOPA applying in such accident scenarios can be expanded. Meanwhile, for the condition that the passive protective layer is not completely effective in the accident scenarios, consequence reduction coefficient is introduced in and correctional program based on accident consequence is presented. All these work is to make the accident frequency calculation results closer to its actual value and finally enhance the accuracy of LOPA analysis.

关键词： Phase frequency detector Accidents Accuracy Statistical analysis Risk management Fires

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Research on Experimental Model of Permafrost Resistivity

Research on Experimental Model of Permafrost Resistivity

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International Conference on Instrumentation, measurement, Computer, communication and control (IMCCC)

作者： Bo Wang Yongqing Jiang Chunxu Wang Zhengmei Liu School of Measurement-Control & Communication Engineering Harbin University of Science and Technology Harbin China

ISBN: (纸本)9781479965762

When the northeast of China steps into winter, the existence of the permafrost makes the traditional ground detection impossible to be accomplished and the soil resistivity jump which lead to the result that the detection cannot be conducted in time or the data of ground resistance test deviates excessively from its actual value in thunderstorm season. As a result, accidents occur frequently. In this paper, through the analysis of the factors which influence the soil resistivity, experimental model of testing resistivity is set, estimate formula of permafrost is given so that the permafrost resistivity can be calculated accurately and thus provide a basis for the design of grounding device in lightning protection project, all these works having positive impact on lightning safety protection and detection.

关键词： Conductivity Soil Temperature measurement Soil measurements Moisture Temperature sensors Temperature distribution

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Numerical Simulation of Leakage and Diffusion of Liquid Ammonia Tank 4th

Numerical Simulation of Leakage and Diffusion of Liquid Ammo...

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International Conference on Instrumentation, measurement, Computer, communication and control (IMCCC)

作者： Bing Pang Chen Liang Lan Ma Bei Luo School of Measurement-Control &Communication Engineering Harbin University of Science and Technology Harbin China

ISBN: (纸本)9781479965762

The model for the leakage and diffusion of liquid ammonia tank established using the species transport and reaction module of Fluent in order to investigate the leakage of liquid ammonia due to storage tank failure. The corresponding influencing laws were obtained by changing the height of leakage source and the size of leakage aperture in the simulation. The potential hazard of liquid ammonia reserved at temperature and high pressure or low temperature and low pressure condition was obtained by comparison of simulation results. The results show that the high concentration of gas diffusion on the leeward side will increase with decreasing height of leakage source, the leakage rate of Ammonia tank and the concentration of gas diffusion on the same location increase as the size of leakage aperture increase, the distance and hazards of gas diffusion during the same time will increase with increasing when using storage mode of normal temperature and high pressure under the same leakage condition.

关键词： Liquids Mathematical model Numerical models Apertures Atmospheric modeling Clouds Computational modeling

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Early faults prediction of running state of electromechanical systems and reconfigurable integration of series safety monitoring systems

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仪器仪表学报 2014年第S2期35卷 224-232页

作者： Xu Xiaoli Zuo Yunbo Chen Tao Liu Xiuli Chen Shanpeng Key Laboratory of Modern Measurement & Control Technology Ministry of Education Beijing Information Science and Technology University School of Mechanical and Vehicle Engineering Beijing Institute of Technology Department of Environmental Science and Engineering Faculty of Bioresources Mie University

Fault prediction technology of running state of electromechanical systems is one of the key technologies that ensure safe and reliable operation of electromechanical equipment in health state. For multiple types of modern, high-end and key electromechanical equipment, this paper will describe the early faults prediction method for multi-type electromechanical systems, which is favorable for predicting early faults of complex electromechanical systems in non-stationary, nonlinear, variable working conditions and long-time running state; the paper shall introduce the reconfigurable integration technology of series safety monitoring systems based on which the integrated development platform of series safety monitoring systems is built. This platform can adapt to integrated R&D of series safety monitoring systems characterized by high technology, multiple species and low volume. With the help of this platform, series safety monitoring systems were developed, and the Remote Network Security Monitoring Center for Facility Groups was built. Experimental research and engineering applications show that: this new fault prediction method has realized the development trend features extraction of typical electromechanical systems, multi-information fusion, intelligent information decision-making and so on, improving the processing accuracy, relevance and applicability of information; new reconfigurable integration technologies have improved the integration level and R&D efficiency of series safety monitoring systems as well as expanded the scope of application; the series safety monitoring systems developed based on reconfigurable integration platform has already played an important role in many aspects including ensuring safety operation of equipment, stabilizing product quality, optimizing running state, saving energy consumption, reducing environmental pollution, improving working conditions, carrying out scientific maintenance, advancing equipment utilization, saving mainten

关键词： electromechanical systems early faults safety control monitoring systems reconfigurable integration

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Finite element simulations of an inchworm type piezo-driven rotary actuator

Finite element simulations of an inchworm type piezo-driven ...

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作者： Huang, Hu Fu, Lu Zhao, Hong Wei Shi, Cheng Li College of Mechanical Science and Engineering Jilin University Changchun Jilin 130025 China AVIC Beijing Chang Cheng Aeronautical Measurement and Control Technology Research Institute Beijing 100176 China

ISBN: (纸本)9783038351221

The inchworm-driven actuator is an important type of piezo-driven actuators, which has high loading capacity, large motion range and high motion accuracy but involves complex structures, control and motion processes. In this paper, an inchworm type piezo-driven rotary actuator was introduced. Static and modal analyses of key units of the rotary actuator such as the clamping unit and the driving unit were carried out by finite element simulations to ensure that key units of the rotary actuator have enough strength and good dynamic characteristics. These simulation results will be helpful to improve structure design of the inchworm actuator. © (2014) Trans Tech Publications, Switzerland.

关键词： Actuators

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