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IEEE Power and Energy Society General Meeting

作者： Huakun Liu Xiaorong Xie Jingbo He Hui Liu Yunhong Li State Key Labor. of Power System Department of Electrical Engineering Tsinghua University National Power Dispatching and Control Center North China Electric Power Research Institute

ISBN: (纸本)9781509041695

Subsynchronous resonance (SSR) issue, namely subsynchronous control interaction (SSCI), was observed in doubly-fed induction generators (DFIGs) based wind farms connected to fixed series compensation. This paper proposes a novel scheme to deactivate SSR by adding subsynchronous suppression filters (SSFs) to DFIG converter controllers. Based on the impedance model analysis, a quantitative index is defined and implemented to identify the "best" location of converter controllers for embedding a SSF. A specific SSF scheme is recommended for practical application, which is to embed a SSF into d-axis channel in inner current loop of rotor-side converter. This scheme has been applied to a practical series-compensated DFIG-based wind farm system located in North China, which has experienced real SSR events. Both impedance analysis and time-domain simulation have validated the effectiveness of the proposed scheme. This control scheme has a broad application prospect due to its easiness to implement and robustness to changeable operating conditions.

关键词： Doubly-fed induction generator (DFIG) Fixed series compensation (FSC) Subsynchronous resonance (SSR) Subsynchronous control interaction (SSCI) Subsynchronous suppression filter PPAN gene semiconductor relays Converters series compensation controllers Current rings impedance analysis Wind farms

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Field Test Results Analysis in Urban Rail Transit Train Ground Communication systems of Integrated Service Using LTE-M

Field Test Results Analysis in Urban Rail Transit Train Grou...

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IEEE International Conference on Intelligent Transportation systems

作者： Tao Tang Keping Dai Yanbing Zhang Hongli Zhao Hailin Jiang State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing Rail Transit Construction and Management Co. Ltd. National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University

ISBN: (纸本)9781509018901

Different services are separated by independent train ground communication networks in existing urban rail transit systems. Most of the independent train ground communication system are using IEEE 802.11 based WLAN technologies, which has many drawbacks when used in urban rail transit system, such as high speed performance degradation, open free frequency, etc. In this paper, we design a train ground communication system for Integrated Service in urban rail transit/metro system using LTE technology (LTE-M). Dedicated frequency spectrum is used in the LTE-M based system. The real LTE-M based system is built on the ring rail line in Beijing to perform the field test. The performance of the integrated services including the CBTC, PIS, IMS and TOSM (Train Operation state Monitoring) are tested. Extensive test results show the advantages of LTE-M. The test results analysis also illustrates the disadvantages of using LTE-M in urban rail, and gives some advises for LTE-M based system design in engineering.

关键词： Rails Rail transportation Wireless LAN Monitoring Delays Quality of service

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Identifying the best machine learning algorithms for brain tumor segmentation, progression assessment, and overall survival prediction in the BRATS challenge

arXiv

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arXiv 2018年

作者： Bakas, Spyridon Reyes, Mauricio Jakab, Andras Bauer, Stefan Rempfler, Markus Crimi, Alessandro Shinohara, Russell Takeshi Berger, Christoph Ha, Sung Min Rozycki, Martin Prastawa, Marcel Alberts, Esther Lipkova, Jana Freymann, John Kirby, Justin Bilello, Michel Fathallah-Shaykh, Hassan M. Wiest, Roland Kirschke, Jan Wiestler, Benedikt Colen, Rivka Kotrotsou, Aikaterini Lamontagne, Pamela Marcus, Daniel Milchenko, Mikhail Nazeri, Arash Weber, Marc-Andr Mahajan, Abhishek Baid, Ujjwal Gerstner, Elizabeth Kwon, Dongjin Acharya, Gagan Agarwal, Manu Alam, Mahbubul Albiol, Alberto Albiol, Antonio Albiol, Francisco J. Alex, Varghese Allinson, Nigel Amorim, Pedro H.A. Amrutkar, Abhijit Anand, Ganesh Andermatt, Simon Arbel, Tal Arbelaez, Pablo Avery, Aaron Azmat, Muneeza Pranjal, B. Bai, Wenjia Banerjee, Subhashis Barth, Bill Batchelder, Thomas Batmanghelich, Kayhan Battistella, Enzo Beers, Andrew Belyaev, Mikhail Bendszus, Martin Benson, Eze Bernal, Jose Bharath, Halandur Nagaraja Biros, George Bisdas, Sotirios Brown, James Cabezas, Mariano Cao, Shilei Cardoso, Jorge M. Carver, Eric N. Casamitjana, Adri Castillo, Laura Silvana Cat, Marcel Cattin, Philippe Cérigues, Albert Chagas, Vinicius S. Chandra, Siddhartha Chang, Yi-Ju Chang, Shiyu Chang, Ken Chazalon, Joseph Chen, Shengcong Chen, Wei Chen, Jefferson W. Chen, Zhaolin Cheng, Kun Choudhury, Ahana Roy Chylla, Roger Clrigues, Albert Colleman, Steven Colmeiro, Ramiro German Rodriguez Combalia, Marc Costa, Anthony Cui, Xiaomeng Dai, Zhenzhen Dai, Lutao Daza, Laura Alexandra Deutsch, Eric Ding, Changxing Dong, Chao Dong, Shidu Dudzik, Wojciech Eaton-Rosen, Zach Egan, Gary Escudero, Guilherme Estienne, Tho Everson, Richard Fabrizio, Jonathan Fan, Yong Fang, Longwei Feng, Xue Ferrante, Enzo Fidon, Lucas Fischer, Martin French, Andrew P. Fridman, Naomi Fu, Huan Fuentes, David Gao, Yaozong Gates, Evan Gering, David Gholami, Amir Gierke, Willi Glocker, Ben Gong, Mingming Gonzlez-Vill, Sandra Grosges, T. Guan, Yuanfang Guo, Sheng Gupta, Sudeep Han, Woo-Sup Han, Il Song Harmuth, Ko Center for Biomedical Image Computing and Analytics University of Pennsylvania PhiladelphiaPA United States Department of Radiology Perelman School of Medicine University of Pennsylvania PhiladelphiaPA United States Department of Pathology and Laboratory Medicine Perelman School of Medicine University of Pennsylvania PhiladelphiaPA United States Institute for Surgical Technology and Biomechanics University of Bern Bern Switzerland Center for MR-Research University Children's Hospital Zurich Zurich Switzerland Support Centre for Advanced Neuroimaging Inselspital Institute for Diagnostic and Interventional Neuroradiology Bern University Hospital Bern Switzerland University Hospital of Zurich Zurich Switzerland Center for Clinical Epidemiology and Biostatistics University of Pennsylvania Philadelphia United States Image-Based Biomedical Modeling Group Technical University of Munich Munich Germany Icahn School of Medicine Mount Sinai Health System New YorkNY United States Leidos Biomedical Research Inc. Frederick National Laboratory for Cancer Research FrederickMD21701 United States Cancer Imaging Program National Cancer Institute National Institutes of Health BethesdaMD20814 United States Department of Neurology University of Alabama at Birmingham BirminghamAL United States Department of Diagnostic Radiology University of Texas MD Anderson Cancer Center HoustonTX United States Department of Psychology Washington University St. LouisMO United States Neuroimaging Informatics and Analysis Center Washington University St. LouisMO United States Department of Radiology Washington University St. LouisMO United States Institute of Diagnostic and Interventional Radiology Pediatric Radiology and Neuroradiology University Medical Center Rostock Ernst-Heydemann-Str. 6 Rostock18057 Germany Tata Memorial Centre Homi Bhabha National Institute Mumbai India Shri Guru Gobind Singhji Institute of Engineering and Technology Nanded India NVIDIA Santa Clara

Gliomas are the most common primary brain malignancies, with different degrees of aggressiveness, variable prognosis and various heterogeneous histologic sub-regions, i.e., peritumoral edematous/invaded tissue, necrotic core, active and non-enhancing core. This intrinsic heterogeneity is also portrayed in their radio-phenotype, as their sub-regions are depicted by varying intensity profiles disseminated across multi-parametric magnetic resonance imaging (mpMRI) scans, reflecting varying biological properties. Their heterogeneous shape, extent, and location are some of the factors that make these tumors difficult to resect, and in some cases inoperable. The amount of resected tumor is a factor also considered in longitudinal scans, when evaluating the apparent tumor for potential diagnosis of progression. Furthermore, there is mounting evidence that accurate segmentation of the various tumor sub-regions can offer the basis for quantitative image analysis towards prediction of patient overall survival. This study assesses the state-of-the-art machine learning (ML) methods used for brain tumor image analysis in mpMRI scans, during the last seven instances of the International Brain Tumor Segmentation (BraTS) challenge, i.e., 2012-2018. Specifically, we focus on i) evaluating segmentations of the various glioma sub-regions in pre-operative mpMRI scans, ii) assessing potential tumor progression by virtue of longitudinal growth of tumor sub-regions, beyond use of the RECIST/RANO criteria, and iii) predicting the overall survival from pre-operative mpMRI scans of patients that underwent gross total resection. Finally, we investigate the challenge of identifying the best ML algorithms for each of these tasks, considering that apart from being diverse on each instance of the challenge, the multi-institutional mpMRI BraTS dataset has also been a continuously evolving/growing dataset. Copyright © 2018, The Authors. All rights reserved.

关键词： Tumors

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Exploring Optimal Frequency Caps in Real Time Bidding Advertising

Exploring Optimal Frequency Caps in Real Time Bidding Advert...

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IEEE International Conference on Big Data and Cloud Computing (BdCloud)

作者： Rui Qin Yong Yuan Fei-Yue Wang Beijing Engineering Research Center of Intelligent Systems and Technology Beijing China The State Key Laboratory of Management and Control for Complex Systems Chinese Academy of Sciences Beijing China Research Center of Military Computational Experiments and Parallel System National University of Defense Technology Changsha China

ISBN: (纸本)9781509039371

Benefited from the high-speed development of Internet and the popularization of big data technology, Real Time Bidding (RTB) emerged and developed quickly, and has become one of the most important and popular model for online computational advertising. In the pay-per-impression based RTB advertising, frequency capping is undoubtedly one of the most crucial issues faced by advertisers and Demand Side Platforms (DSPs), since there are generally vast amount of ad requests in RTB markets, among which many may be triggered by the same target audience. As such, choosing the optimal frequency cap considering all the advertisers becomes a critical issue faced by DSPs. Considering that displaying one advertisement multiple number of times to the same user will diminish the advertising effect, we introduce the concept of discount factor and establish an optimization model of frequency capping to seek for the optimal frequency cap for each advertiser. We also design some experiments to validate our proposed model by utilizing the computational experiment approach, and the experimental results show that the optimal frequency cap can be influenced by the values of the discount factors, and higher value of the discount factor can deduce the advertising effect of larger frequency cap. Moreover, when the discount factors of the advertisers take different values, there also exists an optimal frequency cap, at which the advertisers can get the expected maximum revenue in the long run.

关键词： Advertising Digital signal processing Computational modeling Big data Time-frequency analysis Radio spectrum management Real-time systems

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Optimizing Market Segmentation Granularity in RTB Advertising: A Computational Experimental Study

Optimizing Market Segmentation Granularity in RTB Advertisin...

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IEEE International Conference on Big Data and Cloud Computing (BdCloud)

ISBN: (纸本)9781509039371

Real Time Bidding (RTB) is a novel business model of online computational advertising with the integration of Internet economy and big data analysis. It can help advertisers achieve the precision marketing through the market segmentation strategies of Demand Side Platforms (DSPs). Based on a mathematical programming approach, this paper studied DSPs' strategies for market segmentation, and established a selection model of the granularity for segmenting RTB advertising markets. We proposed to validate our model using the computational experiment approach, and the experimental results show that: 1) with the increasing refinement of the market segmentation granularity, the total revenue has a tendency of a rise first followed by a decline, 2) the optimal granularity of market segmentation will be significantly influenced by the number of advertisers on the DSP, but less influenced by the number of ad requests. Our findings show the crucial role of market segmentation on the RTB advertising effect, and indicate that the DSPs should adjust their market segmentation strategies according to their total number of advertisers. Our findings also highlight the importance of advertisers as well as the characteristics of the target audiences in DSPs' market segmentation decisions.

关键词： Digital signal processing Computational modeling Advertising numerical models Big data Complex systems Automation

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Formal modeling and performance analysis of safety communication protocol in train control system

Formal modeling and performance analysis of safety communica...

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第35届中国控制会议

作者： LIU Hongjie CHEN Lijie Eckehard Schnieder State Key Lab of Rail Traffic Control & Safety Beijing Jiaotong University National Engineering Research Center of Rail Transportation Operation & Control System Beijing Jiaotong University Institute of Standards & Measurements China Academy of Railway Sciences Institute for traffic safety and automation engineering Technical University Braunschweig

ISBN: (纸本)9781509009107

The safety communication protocol is a main factor affecting the train control system. Its performance analysis is of great significance to the train control system. After introducing the procedure of safety communication protocol in the train control system briefly, this paper first explores the application of hierarchy timed Colored Petri Net(CPN) to establish the models of the protocol, including the models of state transition process and the models with time delay and packet loss to imply the influent factors, then collects related performance data such as time for establishment of safety connection, with different time delay and probability of packet loss via simulation. The simulation results could provide a certain reference for the safety communication protocol design and development. Finally, this paper finds how the time delay and packet loss could influent the time for the establishment of safety connection through data interaction process based on theory of probability and mathematical statistic, which is reasonable.

关键词： Safety communication protocol Train control system Petri net Theory of probability Mathematical statistic

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Model-based test case generation for function testing of CTCS-3 onboard subsystem

International Journal of Control and Automation

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International Journal of control and Automation 2015年第10期8卷 171-178页

作者： Lv, Jidong Ren, Pengcheng Lei, Chen Li, Kaicheng Tang, Tao National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University Beijing China State1 Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing China School Of Electronics Electrical and Computer Engineering The University of Birmingham Birmingham United Kingdom

The CTCS-3(Chinese Train control system level 3) is an automatic system which is an integrated of advanced control technology, advanced communication technology, advanced computer technology and railway signal technology. It plays an important role in assuring safety and improving efficiency in railway. As a core subsystem in CTCS-3, the onboard subsystem is a typical safety-critical system, in which any fault can lead to huge human injury or wealth losing. Function testing method which is mainly focus on the conformance relation between the specification and the system Under Test (SUT) has been widely used in testing onboard subsystem in the past few years. However, most of the test cases are manually generated which can 1 be reused and leads to repeated works when the specification is changed. To improve the testing efficiency and quality, model-based testing method is introduced. We use a tool chain to generate test case automatically based on Timed Automata theory and then apply in function testing of onboard subsystem. Firstly, we establish the scenario-tree by analyzing the specification of onboard subsystem and Vital Computer and Environment (V-E) timed automata network model of mode transition using tool Uppaal. Then, according to the relation between train modes and operational scenarios, test cases are automatically generated by tool CoVer with definition coverage criteria based on the Observer Automata theory. Finally, a selection algorithm is given to choose a complete test sequence from the test cases. Different test suitss of onboard subsystem are acquired and compared with different coverage criteria and coverage items. A complete model transition function test suits are derived which is proven very useful for testing the onboard subsystem. © 2015 SERSC.

关键词： Specifications

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Trends of Extreme Precipitation in Eastern China and Their Possible Causes

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Advances in Atmospheric Sciences 2015年第8期32卷 1027-1037页

作者： LIU Run LIU Shaw Chen Ralph J.CICERONE SHIU Chein-Jung LI Jun WANG Jingli ZHANG Yuanhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University Research Center for Environmental Changes Academia Sinica Department of Atmospheric Science NCU National Academy of Sciences Earth System Science University of California Institute of Urban Meteorology of China Meteorological Administration

Significant increases of heavy precipitation and decreases of light precipitation have been reported over widespread regions of the globe. Global warming and effects of anthropogenic aerosols have both been proposed as possible causes of these changes. We examine data from urban and rural meteorological stations in eastern China （1955-2011） and compare them with Global Precipitation Climatology Project （GPCP） data （1979-2007） and reanalysis data in various latitude zones to study changes in precipitation extremes. Significant decreases in light precipitation and increases in heavy precipitation are found at both rural and urban stations, as well as low latitudes over the ocean, while total precipitation shows little change. Characteristics of these changes and changes in the equatorial zone and other latitudes suggest that global warming rather than aerosol effects is the primary cause of the changes. In eastern China, increases of annual total dry days （28 days） and ） 10 consecutive dry days （36%） are due to the decrease in light precipitation days, thereby establishing a causal link among global warming, changes in precipitation extremes, and higher meteorological risk of floods and droughts. Further, results derived from the GPCP data and reanalysis data suggest that the causal link exists over widespread regions of the globe.

关键词： extreme precipitation global warming aerosols meteorological risk of floods and droughts

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Response to Comments by Yuan WANG on “Trends of Extreme Precipitation in Eastern China and Their Possible Causes”

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Advances in Atmospheric Sciences 2015年第10期32卷 1447-1448页

作者： LIU Run LIU Shaw Chen Ralph J.CICERONE SHIU Chein-Jung LI Jun WANG Jingli ZHANG Yuanhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking University Research Center for Environmental Changes Academia Sinica Department of Atmospheric Science NCU National Academy of Sciences Earth System Science University of California Institute of Urban Meteorology of China Meteorological Administration

In his comments, Wang cites a number of works to dispute the conclusion in our previous work, which attributes the observed decreases/increases in light/heavy precipitation in eastern China primarily to global warming rather than the regional aerosol effect. However, most of the cited works （admittedly, including our previous work）, employ correlation analysis, which has little bearing on the cause--effect relationship. Theoretical analyses and/or modeling studies are needed to ascertain the cause-effect relationship. We argue that theoretical analyses and modeling results show that global warming is the primary cause of the widely observed phenomena of suppression of light precipitation and enhancement of heavy precipitation across the globe, including in eastern China.

关键词： extreme precipitation global warming aerosols

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Analysis and modeling of the thermal errors of carriage system of a precision machine tool driven by linear motor

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Key engineering Materials 2014年 579-580卷 645-653页

作者： Yuan, Shuai Peng, Fangyu Zhou, Lin Yao, Peifeng National Numerical Control System Engineering Research Center Huazhong University of Science and Technology Wuhan 430074 China

ISBN: (纸本)9783037858271

The drive system with linear motor of precision machine tools can generate a lot of heat and part of it is conducted to machine tools structures. Therefore, it can lead to the thermal deformation of the structures and hence seriously influences the processing accuracy. In this paper, the finite element model (FEM) considering convection of the planes, the pipelines of the cooler system and thermal resistance is adopted to investigate the thermal distribution and thermal deformation of the carriage system of precision machine tools driven by linear motor. In addition, position-independent thermal errors models of the carriage system are proposed for the main heat source, the primary part of the linear motor, of the carriage system travels with the worktable;the feature genetic algorithm is used to procure the thermal key points of the carriage due to the great number of candidate points. At last, the experiment is conducted on the Y-axis carriage system of precision three-axis machine tool, which demonstrates the two geometric errors δx and Εz caused by the thermal deformation are significantly tiny. The mathematical models of three thermal errors are obtained through the temperatures of the key thermal points because the interferometer cannot measure the roll error Εy. Also, the comparison between the measurements and the thermal errors models indicates that the position-independent thermal models are capable of satisfactorily predicting the magnitude of the other three geometric errors of the carriage system caused by the thermal deformation and also being used in further study of compensation system.

关键词： Genetic algorithms

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