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Beijing Keji Daxue Xuebao/Journal of University of Science and technology Beijing 2009年第SUPPL. 1期31卷 62-66页

作者： Chu, Ying Guo, Han-Jie Yang, Xue-Min Chen, Jun School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China State Key Lab. of Multiphase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

Deoxidization reaction of high grade pipe steel refining in LF was calculated and analyzed in thermodynamics. The reasonable deoxidizer dosage was obtained. The effects of oxides in slag and the slagging process on desulphurization were investigated by comparing the different factors in industrial experiments. A better slag system and indexes were recommended to increase the desulphurization efficiency. The results indicate that the first 20 min during the LF process is the most important period of desulphurization. The new method can shorten the melting time by nearly 8 min.

关键词： Desulfurization

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An automatic online news Topic keyphrase extraction system

An automatic online news Topic keyphrase extraction system

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2008 IEEE/WIC/ACM International Conference on Web Intelligence, WI 2008

作者： Wang, Canhui Zhang, Min Ru, Liyun Ma, Shaoping State Key Lab. of Intelligent Technology and Systems CS and T Department Tsinghua University Beijing 100084 China

ISBN: (纸本)9780769534961

News Topics are related to a set of keywords or keyphrases1. Topic keyphrases briefly describe the key content of topics and help users decide whether to do further reading about them. Moreover, keyphrases of a news topic can be considered as a cluster of related terms, which provides term relationship information that can be integrated into information retrieval models. In this paper, an automatic online news topic keyphrase extraction system is proposed. News stories are organized into topics. keyword candidates are firstly extracted from single news stories and filtered with topic information. Then a phrase identification process combines keywords into phrases using position information. Finally, the phrases are ranked and top ones are selected as topic keyphrases. Experiments performed on practical Web datasets show that the proposed system works effectively, with a performance of precision=70.61% andrecall=67.94%. © 2008 IEEE.

关键词： Extraction

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High level architecture evolved modular federation object model

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Chinese Journal of systems Engineering and Electronics 2009年第3期000卷

作者： Wang Wenguang Xu Yongping Chen Xin Li Qun Wang Weiping Coll. of Information System and Management National Univ. of Defense Technology Changsha 410073 P. R. China Beijing Key Lab. of Intelligent Telecommunications Software and Multimedia Beijing Univ. of Posts and Telecommunications Beijing 100876 P. R. China State Key Lab. for Complex Systems Simulation Beijing 100101 P. R. China

To improve the agility, dynamics, composability, reusability, and development efficiency restricted by monolithic federation object model (FOM), a modular FOM is proposed by high level architecture (HLA) evolved product development group. This paper reviews the state-of-the-art of HLA evolved modular FOM. In particular, related concepts, the overall impact on HLA standards, extension principles, and merging processes are discussed. Also permitted and restricted combinations, and merging rules are provided, and the influence on HLA interface specification is given. The comparison between modular FOM and base object model (BOM) is performed to illustrate the importance of their combination. The applications of modular FOM are summarized. Finally, the significance to facilitate compoable simulation both in academia and practice is presented and future directions are pointed out.

关键词： model federation object model review modular federation object model base. object model com-posability high level architecture evolved simulation

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Automatic hot event detection using both media and user attention

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Journal of Computational Information systems 2008年第3期4卷 985-992页

作者： Wang, Canhui Zhang, Min Ma, Shaoping Ru, Liyun State Key Lab. of Intelligent Technology and Systems CS and T Department Tsinghua University Beijing 100084 China Tsinghua National Laboratory for Information Science and Technology CS and T Department Tsinghua University Beijing 100084 China

Hot events reveal the society's attention and can help to watch the public voice or make decisions. Currently, hot events of various domains are provided by some organizations. Most of the results are considered to be generated manually, which are subjective though costing lots of human efforts. In this paper, a two-stage automatic algorithm for hot event detection is proposed. The first stage is event detection and tracking, in which news stories are organized into events accurately and effectively. The second stage is event ranking, in which both the media and user attention paid to events are taken into consideration. Top ranked events are returned as hot ones. Experiments performed on practical Web datasets show that: (1) F-measure of the best event detection and tracking results is close to 90%;(2) Hot events generated by the proposed algorithm reflect both the media and users' influence on the event ranking, which is considered to be more objective.

关键词： Event detection and tracking Hot event detection Media attention User attention

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Force modeling for tooth preparation in a dental training system

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Virtual Reality 2008年第3期12卷 125-136页

作者： Liu, Guanyang Zhang, Yuru Townsend, William T. State Key Lab. of Virtual Reality Technology and System Beihang University Beijing China Robotics Institute School of Mechanical Engineering and Automation Beihang University Beijing China Barrett Technology Inc. Boston MA United States

Feedback force is very important for novices to simulate tooth preparation by using the haptic interaction system (dental training system) in a virtual environment. In the process of haptic simulation, the fidelity of generated forces by a haptic device decides whether the simulation is successful. A force model computes feedback force, and we present an analytical force model to compute the force between a tooth and a dental pin during tooth preparation. The force between a tooth and a dental pin is modeled in two parts: (1) force to resist human's operation and (2) friction to resist the rotation of the dental engine. The force to resist the human's operation is divided into three parts in the coordinates that are constructed on the bottom center of the dental pin. In addition, we also consider the effects of dental-pin type, tooth stiffness, and contact geometry in the force model. To determine the parameters of the force model, we construct a measuring system by using machine vision and a force/torque sensor to track the human's operations and measure the forces between the dental pins and teeth. Based on the measuring results, we construct the relation between the force and the human's operation. The force model is implemented in the prototype of a dental training system that uses the Phantom as the haptic interface. Dentists performing virtual operations have confirmed the fidelity of feedback force. © Springer-Verlag London Limited 2008.

关键词： Haptic interfaces

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A 1-V switched-opamp sample-and-hold circuit for wideband wireless communication

A 1-V switched-opamp sample-and-hold circuit for wideband wi...

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2008 4th IEEE International Conference on Circuits and systems for Communications, ICCSC

作者： Qin, Yajie Hong, Zhiliang Signell, Svante COS KTH-the Royal Institute of Technology Stockholm Sweden State Key Lab. of ASIC and System Fudan University Shanghai China IEEE

ISBN: (纸本)9781424417087

This paper presents a 1-V 10bit 50MSPS Switched-Opamp (SO) S/H circuit, designed in 3.3V/1.8V 0.18m 1P6M CMOS technology, which could be used in wideband wireless transceivers. A new architecture of the low voltage switchable opamp with improved common-mode feed back (CMFB) loop is introduced for its fast wake-up speed. Simulation results show the S/H circuit achieves a THD of -75dB and a SFDR of 76dB at the Nyquist frequency (Fin = F s/2). The opamp only dissipates a static power of 1.9mW even in active phase. ©2008 IEEE.

关键词： Operational amplifiers

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A low power SHA-less pipelined ADC used in DVB-S2

A low power SHA-less pipelined ADC used in DVB-S2

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2008 9th International Conference on Solid-state and Integrated-Circuit technology, ICSICT 2008

作者： Zhang Zeng, Xiaoyang Li, Jian Xie, Lei Guo, Yawei State Key Lab. of ASIC and System Fudan University Shanghai 201203 China Comlent Technology Inc. Shanghai 201203 China

ISBN: (纸本)9781424421855

A 8-b 125MS/s pipelined Analog-to-Digital Converter (ADC) used in DVB-S2 is presented in this paper. Based on reviewing low-power design techniques of high speed ADCs, several technologies are used in the design including the SHA-less architecture to reduce the power dissipation significantly. Detailed analysis is given about the relationship between the closed loop bandwidth (BW close) and the current of operational amplifier (OPAMP) used in Multiply Digital-to-Analog Converter (MDAC) to get the lowest power dissipation which can satisfy the ADC. The ADC is realized in SMIC 0.18um 1P6M CMOS process and according to the simulation results, the SNDR is 48dB with the power of 23.5mW. © 2008 IEEE.

关键词： Operational amplifiers

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Tool-path generation algorithm of sculptured surface by 3-axis swing grinding

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Jisuanji Jicheng Zhizao Xitong/Computer Integrated Manufacturing systems, CIMS 2008年第7期14卷 1417-1420页

作者： Fan, Li-Cheng Du, Zhi-Jiang Sun, Li-Ning State Key Lab. of Robotics and System Harbin Institute of Technology Harbin 150080 China

In conventional Numerical Control (NC) machining of sculptured surface based on triangular facet model, to calculate each Cutter Location (CL) point of the flatted cutter, only few facets were actually used in the calculation of the tool projection region. However, most calculations were conducted to search those triangular facets overlapped by the tool projection region from the total facet set. To overcome such weakness, a novel rectangle envelope method was proposed, in which most facets outside the projection region were filtered out. During the course of a searching process, all facets overlapped by the tool projection region were saved independently so as to avoid searching the total STL (STereo Lithography) file again in next steps. For each facet overlapped by the tool projection region, the CL point was calculated by the cutter contract points with the vertexes, sides and the plane, finally the tool-path was obtained. Simulation experiment was used to demonstrate the feasibility of the proposed method.

关键词： Grinding (machining)

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Improved flickermeter model for incandescent lamp based on heat balance equation

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Diangong Jishu Xuebao/Transactions of China Electrotechnical Society 2008年第9期23卷 118-124页

作者： Yong, Jing Sun, Caixin Zeng, Liqiang Zhang, Na Hu, Jie State Key Lab. of Power Transmission Equipment and System Security and New Technology Chongqing University Chongqing 400044 China

IEC flickermeter has been widely accepted as an international standard for flicker severity measurement. But it is unable to measure flickers caused by high frequency interharmonics. This paper analyzes the cause of the problem. Based on the heat balance equation and thermal radioluminescence characteristics of incandescent lamp, the equation of luminous flux of lamp that can express the impact of interharmonic is established and an improved flickermeter model is proposed. Comparison between computer simulation of models and lab.experiment results show that the improved flickermeter model can overcome the IEC flickermeter deficiency effectively.

关键词： Incandescent lamps

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Single link tracking scheme based on UWB localization

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Journal of systems Engineering and Electronics 2009年第6期000卷

作者： Xiao Zhu Xiong Hailiang Yu Quan Yi Kechu State Key Lab. of Integrated Service Networks Xidian Univ. Xi'an 710071 P. R. China School of Electronic Science and Engineering National Univ. of Defense Technology Changsha 410073 P. R. China State Key Lab. of Integrated Service Networks Xidian Univ. Xi'an 710071 P. R. China State Key Lab. of Integrated Service Networks Xidian Univ. Xi'an 710071 P. R. China Inst. of China Electronics Equipment System Engineering Corporation Beijing 100039 P. R. China

To investigate the low-complex and high-precise tracking method, a novel single link tracking scheme based on UWB localization is proposed. Two antenna arrays are settled at the fixed station (FS) to receive the UWB signal from mobile terminal (MT), one FS is enough for the proposed scheme to track the MT. The UWB multipath detection algorithm for time difference of arrival (TDOA) estimation is presented and TDOA is thus adopted to estimate angle of arrival (AOA), avoiding the synchronization and complicated beamforming for AOA. The impacts of localization errors, concluding multipath and non-line-of-sight (NLOS) errors are simulated for the proposed track scheme. It is demonstrated that the simulation curve can match the real target moving, and the feasibility of the proposed scheme is proved.

关键词： ultra-wide band localization single-link tracking angle of arrival estimation

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