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IMP & HIRFL Annual Report 1994年 48-49页

作者： guo tianrui and du yifei

Ｏｎ－ｌｉｎｅａｎｄＯｆｆ－ｌｉｎｅＤａｔａＡｃｑｕｉｓｉｔｉｏｎＳｙｓｔｅｍｗｉｔｈＭｉｃｒｏｃｏｍｐｕｔｅｒＴａｐｅＲｅｃｏｒｄｅｒ￥ＧｕｏＴｉａｎｒｕｉａｎｄＤｕＹｉｆｅｉＴｈｉｓｙｅａｒ，ａ...

Ｏｎ－ｌｉｎｅａｎｄＯｆｆ－ｌｉｎｅＤａｔａＡｃｑｕｉｓｉｔｉｏｎＳｙｓｔｅｍｗｉｔｈＭｉｃｒｏｃｏｍｐｕｔｅｒＴａｐｅＲｅｃｏｒｄｅｒ￥ＧｕｏＴｉａｎｒｕｉａｎｄＤｕＹｉｆｅｉＴｈｉｓｙｅａｒ，ａｎｅｗｏｎ－ｌｉｎｅｄａｔａａｃｑ...

关键词：

Design of Double Tape Recorder Data Acquisition System

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IMP & HIRFL Annual Report 1994年 48-48页

作者： guo tianrui and du yifei

ＤｅｓｉｇｎｏｆＤｏｕｂｌｅＴａｐｅＲｅｃｏｒｄｅｒＤａｔａＡｃｑｕｉｓｉｔｉｏｎＳｙｓｔｅｍ￥ＧｕｏＴｉａｎｒｕｉａｎｄＤｕＹｉｆｅｉＩｎｔｈｅｄａｔａａｃｑｕｉｓｉｔｉｏｎｓｙｓｔｅｍｓｕｐｐｏｒｔ...

ＤｅｓｉｇｎｏｆＤｏｕｂｌｅＴａｐｅＲｅｃｏｒｄｅｒＤａｔａＡｃｑｕｉｓｉｔｉｏｎＳｙｓｔｅｍ￥ＧｕｏＴｉａｎｒｕｉａｎｄＤｕＹｉｆｅｉＩｎｔｈｅｄａｔａａｃｑｕｉｓｉｔｉｏｎｓｙｓｔｅｍｓｕｐｐｏｒｔｅｄｂｙｔｈｅｍｉｃｒｏｃｏｍｐｕ...

关键词：

掺硫铝酸钙类膨胀剂白水泥净浆干燥收缩与水分损失关联

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哈尔滨工业大学学报 2025年第1期57卷 140-148页

作者：梁华明朱文彬郭鑫志卢艺菲周春圣哈尔滨工业大学土木工程学院哈尔滨150090 中南安全环境技术研究院股份有限公司武汉430071

为精确解析干燥条件下掺硫铝酸钙类膨胀剂水泥基材料的收缩行为,深入揭示低相对湿度条件下硫铝酸钙类膨胀剂补偿收缩效果下降的机制,利用低场磁共振弛豫技术,结合X射线衍射、质量与长度测试,在不同相对湿度下对掺与不掺硫铝酸钙类膨胀... 详细信息

为精确解析干燥条件下掺硫铝酸钙类膨胀剂水泥基材料的收缩行为,深入揭示低相对湿度条件下硫铝酸钙类膨胀剂补偿收缩效果下降的机制,利用低场磁共振弛豫技术,结合X射线衍射、质量与长度测试,在不同相对湿度下对掺与不掺硫铝酸钙类膨胀剂白水泥净浆的干燥收缩历程进行10个月的长期监测,从含水量及水分状态角度,定量描述白水泥净浆干燥失水和收缩的演变规律,阐明硫铝酸钙类膨胀剂导致干燥收缩落差增大的作用机制。结果表明:在相对湿度为75%、43%、11%的环境中干燥,白水泥净浆失水量和干燥收缩均持续增大直至稳定,3类环境中各试件干燥收缩与相对失水量间的关系基本保持一致;随干燥时间延长,单位失水量导致的干燥收缩先降低后升高,干燥进程中净浆内部各级孔隙失水规律不同,且各湿度条件下的干燥收缩机制存在差异;掺入硫铝酸钙类膨胀剂后,C-S-H凝胶纳米孔结构会发生一定粗化,干燥时易损失更多可蒸发水,且膨胀剂水化生成的钙矾石还会损失2~5个结晶水,二者共同导致净浆水分损失与干燥收缩增大;在低湿度环境中应用硫铝酸钙类膨胀剂时,需注意这两个因素导致收缩落差增大的影响。

关键词：白水泥硫铝酸钙类膨胀剂干燥收缩水分损失低场磁共振

Moving scanning emitter tracking by a single observer using time of interception:Observability analysis and algorithm

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Chinese Journal of Aeronautics 2017年第3期30卷 1174-1183页

作者： yifei ZHANG Min ZHANG Fucheng guo Information Engineering Department Rocket Force University of Engineering College of Electronic Science and Engineering National University of Defense Technology

The target motion analysis（TMA） for a moving scanning emitter with known fixed scan rate by a single observer using the time of interception（TOI） measurements only is investigated in this *** transforming the TOI of multiple scan cycles into the direction difference of arrival（DDOA） model,the observability analysis for the TMA problem is *** necessary conditions for uniquely identifying the scanning emitter trajectory are *** paper also proposes a weighted instrumental variable（WIV） estimator for the scanning emitter TMA,which does not require any initial solution guess and is closed-form and computationally *** importantly,simulations show that the proposed algorithm can provide estimation mean square error close to the Cramer-Rao lower bound（CRLB） at moderate noise levels with significantly lower estimation bias than the conventional pseudo-linear least square（PLS） estimator.

关键词： Cramer-Rao lower bound Least squares Observability Scanning emitter Target motion analysis Time of interception

Improving　and　Going　UP　of　MOLDAS　I　Multi－Parameter　General　Data　Acquisition　System

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IMP & HIRFL Annual Report 1994年 46-47页

作者： Ge Yuanxiu Shen Cuihua Wang Chunfang du yifei and guo tianrui

ＩｍｐｒｏｖｉｎｇａｎｄＧｏｉｎｇＵＰｏｆＭＯＬＤＡＳＩＭｕｌｔｉ－ＰａｒａｍｅｔｅｒＧｅｎｅｒａｌＤａｔａＡｃｑｕｉｓｉｔｉｏｎＳｙｓｔｅｍ￥ＧｅＹｕａｎｘｉｕ；ＳｈｅｎＣｕｉｈｕａ；ＷａｎｇＣｈｕｎｆａｎｇ；Ｄｕ...

ＩｍｐｒｏｖｉｎｇａｎｄＧｏｉｎｇＵＰｏｆＭＯＬＤＡＳＩＭｕｌｔｉ－ＰａｒａｍｅｔｅｒＧｅｎｅｒａｌＤａｔａＡｃｑｕｉｓｉｔｉｏｎＳｙｓｔｅｍ￥ＧｅＹｕａｎｘｉｕ；ＳｈｅｎＣｕｉｈｕａ；ＷａｎｇＣｈｕｎｆａｎｇ；ＤｕＹｉｆｅｉａｎｄＧｕｏＴｉａｎｒｕ...

关键词：

Applications of survival functions to continuous semi-Markov processes for measuring reliability of power transformers

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Journal of Modern Power Systems and Clean Energy 2017年第6期5卷 959-969页

作者： yifei WANG Mohammad SHAHIDEHPOUR Chuangxin guo School of Automation Guangdong University of TechnologyGuangzhou 510006China Galvin Center for Electricity Innovation Illinois Institute of TechnologyChicagoIL 60616USA College of Electrical Engineering Zhejiang UniversityHangzhou 310058China

The reliability of power transformers is subject to service age and health *** paper proposes a practical model for the evaluation of two reliability indices:survival function(SF)and mean residual life(MRL).In the proposed model,the periodical modeling of power transformers are considered for collecting the information on health *** corresponding health condition is assumed to follow a continuous semi-Markov process for representing a state *** proportional hazard model(PHM)is introduced to incorporate service age and health condition into hazard *** addition,the proposed model derives the analytical formulas for and offers the analytical evaluation of SF and *** and MRL are calculated for new components and old components,*** both cases,the proposed model offers rational results which are compared with those obtained from comparative *** results obtained by the contrast of the proposed analytical method and the Monte Carlo *** impact of differentmodel parameters and the coefficient of variation(CV)on reliability indices are discussed in the case studies.

关键词： Power system reliability Transformers Proportional hazard model Survival function Mean residual life Semi-Markov process

Deep Q-Learning Based Computation Offloading Strategy for Mobile Edge Computing

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Computers, Materials & Continua 2019年第4期59卷 89-104页

作者： yifei Wei Zhaoying Wang Da guo FRichard Yu Beijing Key Laboratory of Work Safety Intelligent Monitoring School of Electronic EngineeringBeijing University of Posts and TelecommunicationsBeijing100876China Department of Systems and Computer Engineering Carleton UniversityOttawaON K1S 5B6Canada

To reduce the transmission latency and mitigate the backhaul burden of the centralized cloud-based network services,the mobile edge computing(MEC)has been drawing increased attention from both industry and academia *** paper focuses on mobile users’computation offloading problem in wireless cellular networks with mobile edge computing for the purpose of optimizing the computation offloading decision making *** wireless network states and computing requests have stochastic properties and the environment’s dynamics are unknown,we use the modelfree reinforcement learning(RL)framework to formulate and tackle the computation offloading *** mobile user learns through interactions with the environment and the estimate of its performance in the form of value function,then it chooses the overhead-aware optimal computation offloading action(local computing or edge computing)based on its *** state spaces are high-dimensional in our work and value function is unrealistic to ***,we use deep reinforcement learning algorithm,which combines RL method Q-learning with the deep neural network(DNN)to approximate the value functions for complicated control applications,and the optimal policy will be obtained when the value function reaches *** results showed that the effectiveness of the proposed method in comparison with baseline methods in terms of total overheads of all mobile users.

关键词： Mobile edge computing computation offloading resource allocation deep reinforcement learning

Implementation of Abstract MAC Layer Under Jamming

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Tsinghua Science and Technology 2022年第2期27卷 257-269页

作者： yifei Zou Minghui Xu Dongxiao Yu Liandong Chen Shaoyong guo Xiaoshuang Xing School of Computer Science and Technology Shandong UniversityQingdao 266237China Information and Telecommunication Branch State Grid Hebei Electric Power Company Ltd.Shijiazhuang 050022China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China School of Computer Science and Engineering Changshu Institute of TechnologyChangshu 215500China

In the past decades,with the widespread implementation of wireless networks,such as the Internet of Things,an enormous demand for designing relative algorithms for various realistic scenarios has ***,with the widening of scales and deepening of network layers,it has become increasingly challenging to design such algorithms when the issues of message dissemination at high levels and the contention management at the physical layer are ***,the abstract medium access control(absMAC)layer,which was proposed in2009,is designed to solve this ***,the absMAC layer consists of two basic operations for network agents:the acknowledgement operation to broadcast messages to all neighbors and the progress operation to receive messages from *** absMAC layer divides the wireless algorithm design into two independent and manageable components,i.e.,to implement the absMAC layer over a physical network and to solve higher-level problems based on the acknowledgement and progress operations provided by the absMAC layer,which makes the algorithm design easier and *** this study,we consider the implementation of the absMAC layer under *** efficient algorithm is proposed to implement the absMAC layer,attached with rigorous theoretical analyses and extensive simulation *** on the implemented absMAC layer,many high-level algorithms in non-jamming cases can be executed in a jamming network.

关键词： abstract MAC layer distributed algorithm Rayleigh-fading model jamming networks

Thermodynamic Analysis of Packed Bed Thermal Energy Storage System

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Journal of Thermal Science 2020年第2期29卷 445-456页

作者： guo Huan XU Yujie guo Cong CHEN Haisheng WANG yifei YANG Zheng HUANG Ye DOU Binlin Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China School of the Built Environment University of UlsterCo.Antrim BT370QBUK School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China

A packed-bed thermal energy storage(PBTES) device, which is simultaneously restricted by thermal storage capacity and outlet temperatures of both cold and hot heat transfer fluids, is characterized by an unstable operation condition, and its calculation is complicated. To solve this problem, a steady thermodynamics model of PBTES with fixed temperatures on both ends was built. By using this model, the exergy destruction, thermocline thickness, thermal storage capacity, thermal storage time, and other key parameters can be calculated in a simple way. In addition, the model explained the internal reason for the change of thermocline thickness during thermal storage and release processes. Furthermore, the stable operation of the PBTES device was analyzed, and it was found that higher inlet temperature of hot air, and lower temperature difference between cold and hot air can produce less exergy destruction and achieve a larger cycle number of stable operation. The work can be employed as the basis of the design and engineering application of PBTES.

关键词： packed bed thermal energy storage thermocline steady thermodynamic analysis stable operation

Synergistic defensive mechanism of phytochelatins and antioxidative enzymes in Brassica chinensis L. against Cd stress

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Chinese Science Bulletin 2008年第10期53卷 1503-1511页

作者： CHEN LiQin guo yifei YANG LiMin WANG QiuQuan Department of Chemistry and the MOE Key Laboratory of Modern Analytical Science College of Chemistry and Chemical Engi- neering Xiamen University Xiamen 361005 China State Key Laboratory of Marine Environmental Science Xiamen University Xiamen 361005 China

Brassica chinensis L. was chosen and exposed to different concentrations of Cd exposure to evaluate its Cd-accumulating capacity and its potential cellular defensive mechanisms. Cd accumulation in the shoots and roots of B. chinensis was up to 1348.3±461.8 and 3761.0±795.0 mg per killogram of dry weight, respectively, under 200 μmol/L of Cd exposure. Increasing Cd accumulation in the plant was accompanied by rapid accumulation of phytochelatins (PCs), and the sequestration of Cd by PCs provided a primary cellular mechanism for Cd detoxification and tolerance of B. chinensis. Furthermore, malondialdehyde formation, hydrogen peroxide content and antioxidative enzyme activities such as superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase were observed in the shoots of Cd-stressed B. chinensis. Increasing enzyme activities in response to concentrations of 5 to 50 μmol/L Cd showed an efficient defense against oxidative stress, suggesting that the antioxidative system was a secondary defensive mechanism. These resulted in reduced free Cd damage and enhanced Cd accumulation and tolerance. Glutathione plays a pivotal role in these two detoxification pathways. In general, these results suggested that PCs and the antioxidative system are synergistic in combatting Cd-induced oxidative stress and that they play important roles in Cd detoxification of B. chinensis, and also give a deep understanding of the natural defensive mechanisms in plants under heavy metal stress.

关键词：镉芸苔植物化学酶类