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Study on optimized algorithm for mileage wheel of magnetic flux leakage detector

IOP Conference Series: Materials Science and engineering 2017年第1期220卷

作者： L Y Sun Y B Li Y T Wu Q Y Xu Y Cai School of Control and Mechanical Engineering Tianjin Chengjian University Tianjin 300384 China State Key Lab. of Precision Measurement Technology and Instrument Tianjin University Tianjin 300072 China

Pipeline integrity is significant to safe operation of long-range pipeline. To avoid critical failure of the pipeline, which may lead to great loss of property and life, MFL_PIG is often used to detect the corrosion and leakage of the pipeline. To accurately locate the defects, mileage pulses emitted by the mileage wheel are used to and emit signal to single-chip microcomputer for position. This paper investigates the factors that may affect the precision of mileage wheel, an important part of pipeline corrosion and leakage detector (MFL_PIG), investigate its working principle and present an optimized algorithm for mileage wheel to increase the precision of detection.

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Establishment of magnetic sensors in above ground marking system

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IOP Conference Series: Materials Science and engineering 2017年第1期220卷

作者： L Y Sun Y B Li Y T Wu W P Li P Q Wu School of Control and Mechanical Engineering Tianjin Chengjian University Tianjin 300384 China State Key Lab. of Precision Measurement Technology and Instrument Tianjin University Tianjin 300072 China

Magnetic sensors used in Above Ground Markers (AGM) to measure the magnetic field signals are one of the main parts of AGM. By collecting the change of magnetic field parameter using magnetic sensors, AGM can record the precise time when MFL_PIG is passing by the AGM. In this paper, the magnetic sensors, such as induced coil and magneto-resistive sensor, are investigated in characteristics and performance of measurement. With advantages of low cost, high resolution and wide range of measurement, the induced coil is adopted in a novel AGM. The traction test, seal ability test and temperature test show that the AGM with induced coil as magnetic sensor works well under extreme condition and reacts to change the magnetic field with high sensibility.

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Research of Ofloxacin Based on Terahertz Spectrum

Research of Ofloxacin Based on Terahertz Spectrum

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2016 4th International Conference on Machinery,Materials and Information Technology Applications(ICMMITA 2016)

作者： Song Zhang Xiai Chen Xiaohong Gu Qiang Wang Ling Wang School of Mechanical and Electrical Engineering China Jiliang University Zhejiang Yalong Educational Equipment Joint-Stock Co. Ltd State Key Lab. of Industrial Control Technology Department of Control Science and EngineeringZhejiang University

The absorption coefficient, refractive index and optical fingerprint characteristics were acquired by terahertz time-domain spectroscopy in the range of 0.4.5THz of the capsule drug ofloxacin. The results show that ofloxacin had multiple absorption peaks with different intensities within the frequency range, and the absorption coefficient spectrum could be used for the identification of ofloxacin. In the range of 0.4.5THz,the absorption spectra of ofloxacin molecules were simulated by Gaussion software. The vibration modes of some absorption peaks in the absorption spectra were analyzed and identified using the density functional theory. At 1.06 and 1.13 THz, the experimental results show that the absorption peaks are consistent with the absorption peaks of 1.07 and 1.18 THz in the theoretical spectrum, which are caused by the vibrational modes in the molecule ofloxacin.

关键词： Terahertz time-domain spectroscopy Absorption spectrum Density functional theory Ofloxacin

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Study on climbing locomotion mechanism of snake robot with universal unit

Study on climbing locomotion mechanism of snake robot with u...

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International Conference on Modelling, Identification and control (ICMIC)

作者： Chao Wang Hong-bin Deng Fei Xia Yang Li School of Mechatronics Engineering Nat. Key Lab. of Electro-Mech. Syst. & Control Beijing Institute of Technology Beijing China State Grid Liaoyang Electric Power Supply Company Liaoning China CETC International Co. Ltd Beijing China

ISBN: (纸本)9781509015948

Snake robot with universal unit is presented and studied in this paper. The universal unit greatly improves snake robot's dexterity in space, complexities in actions and varieties in kinetic pattern. The balance principle of the snake robot during climbing is analyzed. To imitate a biological snake to climb, inchworm locomotion gait along the direction of isometric spiral curve is adopted. Motion parameters functions of the snake robot are derived.

关键词： Robot kinematics Spirals Joining processes Friction Shape Biology

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Detection method for the burst signal in a low SNR

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Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University 2016年第6期43卷 164-169页

作者： Chen, Dan Liu, Mingqian Zhang, Yang Hu, Ye School of Electronics and Control Engineering Chang'an Univ. Xi'an710064 China State Key Lab. of Integrated Service Networks Xidian Univ. Xi'an710071 China National Mobile Communications Research Laboratory Southeast Univ. Nanjing210096 China

A detection method for the burst signal based on the cepstrum of the power spectrum is proposed to solve the problem of the poor burst signal detection performance in the low SNR environment. First, the maximum value of the spectrum is used as the test statistic and is smoothed by the smooth window. Then, the K-mean clustering algorithm is used to classify the decision to distinguish the signal and the noise. Finally, the detection of the burst signal is completed by the three-state transition based on the length. Simulation results show that the proposed method has a better detection performance and lower computational complexity in low SNR environments. © 2016, The Editorial Board of Journal of Xidian University. All right reserved.

关键词： Signal detection

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Geometry-based uplink channel reuse in cellular D2D underlays

Geometry-based uplink channel reuse in cellular D2D underlay...

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International Symposium on Wireless Personal Multimedia Communications (WPMC)

作者： Zilong Wu Minming Ni Li Wang Mei Song Chuyi Guo School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing China State Key Lab. of Rail Traffic Control and Safety Beijing Jiaotong University Beijing china National Mobile Communications Research Laboratory Southeast University Nanjing China

ISBN: (纸本)9781509053773

Device-to-Device (D2D) communications are promising technologies to improve the spectrum efficiency, network throughput, and transmission latency for short-range communications in underlaid cellular networks. In this paper, we investigate the resource allocation for multiple D2D pairs in underlaid cellular networks. By utilizing the Power Emission Density-based interference modeling method, the impact of the accumulated interference generated from multiple D2D pairs reusing the same cellular user radio resource is carefully studied. With these analytical results, the cell area is divided into multiple non-overlapped rings, wherein D2D pairs communicating with the same radio resource but located in different rings will not influence each other's reception. Based on the division, the resource allocation can be simultaneously conducted with a newly proposed scheme in different rings, which considerably shrinks the reusing candidate set and reduces the computation complexity. Intensive simulations verify our analytical results and show that the proposed scheme can greatly enhance the performance of the resource allocation.

关键词： Device-to-device communication Interference Resource management Uplink Radio transmitters Erbium Cellular networks

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Coupling effects of mechanical vibrations and thermal cycling on reliability of CCGA solder joints

Coupling effects of mechanical vibrations and thermal cyclin...

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作者： Ding, Ying Tian, Ruyu Wang, Xiuli Hang, Chunjin Yu, Fang Zhou, Ling Meng, Xiangang Tian, Yanhong Beijing Institute of Control Engineering Beijing100190 China State Key Lab. of Advanced Welding Production Technology Harbin Institute of Technology Harbin150001 China

The microstructures and crack propagation behavior of CCGA (ceramic column grid array) solder joints after sinusoidal vibration loading, random vibration loading, and thermal cycling test have been discussed in this study. The failure mechanism of solder joints was analyzed using an experimental method and finite element analysis. It was found that the failed solder joints mainly distributed at the peripheral area in the solder column arrays and the crack initiation was mainly caused by mechanical vibrations. The deformation of PCB (printed circuit board) introduced by mechanical vibrations brought the outermost solder columns in CCGA devices with significant stress concentration and induced the initiation of cracks. Furthermore, cracks propagated during the process of mechanical vibrations and thermal cycling. The cracks propagated rapidly and the solder joints finally failed. The structure of the PCB holder was improved to relieve the vibration response from the peripheral joints. No visible crack was found in the solder joints after the same mechanical vibrations and thermal cycling test. The reliability of solder joints have been greatly improved with the new PCB holder. © 2015 Elsevier Ltd. All rights reserved.

关键词： Vibrations (mechanical)

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Risk-averse procurement strategy in presence of strategic customer 45

Risk-averse procurement strategy in presence of strategic cu...

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45th International Conference on Computers and Industrial engineering, CIE 2015

作者： Shu, Lei Wu, Feng School of Management Key Lab. of the Ministry of Education for Process Control and Efficiency Engineering Experiment Center for the Teaching of Management Education Xi'an Jiaotong University Demo-Center at State Level for Experiment Teaching China

LArising in online environment lately due to frequent dynamic pricing in presence of strategic customer, pulsed demand increases the risk of a retailer as it is large and highly uncertain. Moreover, it shifts between periods because of customer strategic behavior. This paper, from the perspective of a risk-averse retailer, establishes a procurement model and a strategic customer demand model, to analyze the effects of strategic customer, pricing and risk aversion on order quantity, profit and risk. Some useful conclusions for procurement risk control are drawn in the setting of two-period. Selling price of period 1 affects order quantity of period 2, when strategic customer ratio is independent of prices;while all selling prices affect all order quantities when dependent. Order quantity in period 1 (period 2) decreases (increases) in strategic customer ratio, which would be less sensitive when the retailer is more risk-averse. Besides, risk-aversion procurement can effectively and significantly mitigate risk without much loss of profit, especially when strategic customer ratio is large.

关键词： Profitability

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Enhanced biological nutrient removal in modified carbon source division anaerobic anoxic oxic process with return activated sludge pre-concentration

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Chinese Journal of Chemical engineering 2015年第6期23卷 1027-1034页

作者：鲁骎毋海燕李昊岩杨殿海 State Key Lab. of Pollution Control and Resources Reuse College of Environmental Sciences and Engineering Tongji University Xylem (China) Co. Ltd. Shanghai Plant Biomass Co. Ltd.

A pilot-scale modified carbon source division anaerobic anoxic oxic(AAO) process with pre-concentration of returned activated sludge(RAS) was proposed in this study for the enhanced biological nutrient removal(BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratio were investigated. The results show that the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60% and 50%, respectively, with an inner recycling ratio of 100% under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L-1with a removal efficiency of 63% and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test.

关键词： Modified AAO process Carbon source distribution ratio Returned activated sludge pre-concentration Biological nutrient removal

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A SVD-Based Optimum Algorithm Research for Macro-Femto Cell Interference Coordination

A SVD-Based Optimum Algorithm Research for Macro-Femto Cell ...

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IEEE Vehicular Technology Conference

作者： Kaiyue Yan Yan Yang Shuping Dang State Key Lab. of Rail Traffic Control and Safety Beijing Jiaotong University Department of Engineering Science University of Oxford

ISBN: (纸本)9781479980895

The intra-tier interference in heterogeneous networks becomes more serious when the number of macro-femto cells dramatically increases. Based on the singular value decomposition (SVD) algorithm, this paper proposes an optimized interference alignment (IA) algorithm to improve the macro-femto cell downlink rate. To achieve the largest degrees of freedom (DOF), we adopt the precoding matrix as a powerful tool to mitigate the effect of inter-channel interference (ICI). In comparison with the conventional interference coordination methods, the SVD algorithm is capable of adjusting the coefficients of the precoding matrix with lower complexity. Furthermore, zero-forcing algorithm is also used to combat ICI in this proposed IA algorithm. The numerical results show that ICI can be suppressed effectively and the system performance in terms of throughput and signal-to-interference-plus-noise ratio (SINR) can be improved considerably.

关键词： Heterogeneous network Macro-femto cell Interference alignment Singular value decomposition Precoding matrix

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