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Exploration of combined adjustment laws about IGV,stator and rotational speed in off-design conditions in an axial compressor

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中国科学：技术科学英文版 2010年第4期53卷 969-975页

作者： HU YanMing1,2 & NIE ChaoQun1 1 Key Laboratory of Advanced Energy and Power technology,institute of Engineeting Thermophysics,chinese academy of science,beijing 100190,china 2 Graduate school of chinese academy of sciences,beijing 100190,china 1. Key Laboratory of Advanced Energy and Power technology Institute of Engineeting Thermophysics Chinese Academy of Science Beijing 100190 China2. Graduate School of Chinese Academy of Sciences Beijing 100190 China

Experimental investigations are performed in a three-stage low-speed axial compressor with variable inlet guide vanes(IGV) and adjustable *** characteristics of the compressor,especially the efficiency and stall margin,are analyzed in design and off-design operation conditions by adjusting stagger angles of IGV and stators as well as changing the rotational *** experimental results show that the off-design performance of the multistage axial compressor is improved by restaggering of IGV and stators related to rotational *** the background of engineering applications,digital signal processing(DsP) technique is used to realize online adjustment of stagger angles according to the corresponding relations between incidence angles of rotor and rotational speed.

关键词： axial compressor IGV surge DsP techniques off-design

A direct product decomposition of QMV algebras

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science china Mathematics 2012年第4期55卷 841-850页

作者： LU Xian 1 ,sHANG Yun 1,& LU RuQian 1,2 1 institute of Mathematics,academy of Mathematics and systems science,beijing 100190,china 2 Key Laboratory of Intelligent Information Processing,institute of computing technology,chinese academy of sciences,beijing 100190,china 1. institute of Mathematics Academy of Mathematics and Systems Science Beijing 100190 China2. Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

We study the direct product decomposition of quantum many-valued algebras (QMV algebras) which generalizes the decomposition theorem of ortholattices (orthomodular lattices).In detail,for an idempo- tent element of a given QMV algebra,if it commutes with every element of the QMV algebra,it can induce a direct product decomposition of the QMV *** the same time,we introduce the commutant C(s) of a set s in a QMV algebra,and prove that when s consists of idempotent elements,C(s) is a subalgebra of the QMV *** also generalizes the cases of orthomodular lattices.

关键词： QMV algebra commutativity idempotent decomposition theorem

The correspondence between the concepts in description logics for contexts and formal concept analysis

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science china(Information sciences) 2012年第5期55卷 1106-1122页

作者： MA Yue 1,2.sUI YueFei 1 & CAO CunGen 1 1 Key Laboratory of Intelligent Information Processing,institute of computing technology,chinese academy of sciences,beijing 100190,china 2 Graduate University of chinese academy of sciences,beijing,china 1. Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Formal concept analysis (FCA) and description logic (DL) are meant to be formalizations of concepts.A formal concept in the former consists of its intent and extent,where the intent is the set of all the attributes shared by each object in the extent of the concept,and the extent is the set of all the objects sharing each property in the intent of the concept.A concept in the latter formalization is simply a concept name,the interpretation of which is a subset of a *** consider the correspondence between concepts in both formalizations,a multi-valued formal context must be represented both as a knowledge base and as a model of the DL for contexts,where concepts are decomposed into tuple concepts C,interpreted as a set of tuples and value concepts V,interpreted as a set of attribute-value *** show that there is a difference between the interpretation of concepts R.V /R.C and the Galois connection between the extent/intent of formal concepts in *** to the Galois connection,there should be concepts of the form + R.V and + R.C inter-preted in FCA,and hence the logical language L for DL is extended to be L + together with + as a constructor so that + R.V and + R.C are well-defined ***,according to the interpretation in DL there should be pseudo concepts in FCA so that the interpretation of concepts R.V /R.C is the extent/intent of pseudo *** correspondence between formal concepts and concepts in L +,and between pseudo concepts and concepts in L are presented in this paper.

关键词： description logic formal concept analysis concept attribute/role

Giant complete automaton for uncertain multiple string matching and its high speed construction algorithm

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science china(Information sciences) 2011年第8期54卷 1562-1571页

作者： HU Yue 1,2, GAO Qingshi 1,2 ,GUO Li 2 & WANG PeiFeng 1 1 school of Information Engineering,University of science and technology beijing,beijing 100083,china 2.institute of computing technology,chinese academy of sciences,beijing 100190,china 1. school of Information Engineering University of Science and Technology Beijing Beijing 100083 China2. Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

Multiple string matching is often completed under the presence of U- or V-uncertain-strings,or combinations *** large numbers of strings with U-, V-,and U-V-uncertain-strings,including the interleaving of two or more uncertain strings,is important to thoroughly gathering useful information and detecting harmful *** paper proposes a complete automaton and its high-speed construction algorithm for large-scale U-, V-,and U-V-uncertain multiple strings,including two or more uncertain strings interlaced with one *** maximum number of parallel complete automation of the V-uncertain string is also *** paper reveals that there are two kinds of pretermissions,i.e.,similarly-connected and interlaced-string pretermissions,and that mistake may appear in the matching of the regular expressions,or states in the automaton may increase in number,if the intersection of the U-uncertain strings sets and the homologous subsequent special point in the U-uncertain strings sets are not eliminated from the whole system.

关键词： multiple string matching U-uncertain-strings V-uncertain-strings U-V-uncertain-strings complete automaton

simulation of aerodynamic performance affected by vortex generators on blunt trailing-edge airfoils

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science china(Technological sciences) 2010年第1期53卷 1-7页

作者： YANG Ke1,2,ZHANG Lei1,3 & XU JianZhong1,2 1 institute of Engineering Thermophysics,chinese academy of sciences,beijing 100190,china 2 Key Laboratory of Wind Energy Utilization,chinese academy of sciences,beijing 100190,china 3 Graduate school of chinese academy of sciences,beijing 100190,china 1. institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China2. Key Laboratory of Wind Energy Utilization Chinese Academy of Sciences Beijing 100190 China3. Graduate School of Chinese Academy of Sciences Beijing 100190 China

An investigation was carried out by numerical simulation on a wind turbine airfoil and a blunt trailing-edge airfoil with and without vortex generators (VGs), and the performance of the airfoils was analyzed. By the simulation of airfoil DU 91-W2-250 it was verified that the numerical method and model were credible. Based on this airfoil, a new one with a blunt trailing edge of 6% chord was blended by symmetrically adding thickness, and its characteristics curves were obtained through computing at key angles of attack. Additionally, the pressure distribution on blended airfoil was analyzed by comparing to the airfoil without blend. The interaction of streamwise vortices induced by VGs with trailing vortex or separation vortex was considered, followed by the uncovery of how VGs can suppress the boundary layer separation.

关键词： vortex generators airfoil blunt trailing-edge

strict constraints on 2D primitive pairs for engineering symbol recognition:Theory and application

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science china(Information sciences) 2012年第5期55卷 1032-1041页

作者： LI Ting 1,2,QIU XianJie 1,HUANG He 1 & WANG ZhaoQi 1 1 Virtual Reality Laboratory,institute of computing technology chinese academy of sciences,beijing 100190,china 2 Graduate University of chinese academy of sciences,beijing 100049,china 1. Virtual Reality Laboratory Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Geometric constraints on the line-line pair,line-arc pair and arcarc pair are *** con-straints are able to encode the geometric relations between lines,arcs and circles.A geometric proof is presented to demonstrate that the constraints are stable under translation,rotation,uniform scaling or reflection of the primitive *** on the constraints,an algorithm for recognizing symbols in drawings is ***-perimental results show that,compared with three other methods,our method can distinguish more primitive pairs and has higher accuracy in engineering symbol recognition.

关键词： coordinated multi-point transmission multicell cooperation capacity analysis MIMO-OFDM power allocation frequency selective MIMO channel

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笔谈:透视台湾地区2024年“两项选举”

台湾研究 2024年第1期 1-14页

作者： institute of Taiwan studies, chinese academy of social sciences 中国社会科学院台湾研究所

2024年1月13日,台湾地区领导人和立法机构“二合一”选举落下幕。民进党籍候选人赖清德、萧美琴当选台湾地区正副领导人。台湾地区立法机构总额113席中,中国国民党获52席,民进党获51席,民众党获8席,无党籍及未经政党推荐者获2席.

关键词：中国国民党民进党立法机构台湾地区民众党推荐者二合一候选人

A novel operation mode for spaceborne polarimetric sAR

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science china(Information sciences) 2011年第4期54卷 884-897页

作者： QI WeiKong 1,2 & YU WeiDong 1 1 institute of Electronics,chinese academy of sciences,beijing 100190,china 2 Graduate school of chinese academy of sciences,beijing 100039,china 1. institute of Electronics Chinese Academy of Sciences Beijing 100190 China2. Graduate School of Chinese Academy of Sciences Beijing 100039 China

A novel operation mode for spaceborne polarimetric sAR,named polarization space-division adding polarization code-division (PsD-PCD) operation mode,is proposed in this paper through combining polarimetric sAR with elevation digital beam-forming (DBF) on *** a pulse repetition interval the up-chirp LFM sub-pulse is transmitted with horizontal polarization antenna,and with some delay the down-chip LFM subpulse is transmitted with vertical polarization antenna to realize code *** every sub-aperture receives returns from ground,sAR system uses range DBF to separate echoes relative to different sub-pulses in order to realize space *** system PRF is equal to that of single-polarization sAR,and elevation DBF help reduce range ambiguity ***,the main system parameters,including PRF,delay between two sub-pulses,radar equation and ambiguity are analyzed and compared with those of single-polarization *** results demonstrate the feasibility and validity of PsD-PCD operation mode.

关键词： spaceborne synthetic aperture radar (sAR) polarimetry digital beamforming (DBF) operation mode ambiguity ratio polarization space-division polarization code-division

Maximal effective baseline for polarimetric interferometric sAR forest height estimation

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science china(Information sciences) 2012年第4期55卷 867-876页

作者： ZHOU Yongsheng 1,2,3,HONG Wen 1,2,WANG YanPing 1,2 & WU YiRong 1,2 1 National Key Laboratory of science &technology on Microwave Imaging,beijing 100190,china 2.institute of Electronics,chinese academy of sciences,beijing 100190,china 3 academy of Opto-Electronics,chinese academy of sciences,beijing 100094,china 1. National Key Laboratory of science & technology on Microwave Imaging Beijing 100190 China2. Institute of Electronics Chinese Academy of Sciences Beijing 100190 China3. Academy of Opto-Electronics Chinese Academy of Sciences Beijing 100094 China

The concepts of critical baseline and maximal effective baseline have been defined for interferometric sAR (InsAR) DEM application based on the spatial decorrelation (which is a function of baseline).This paper puts forward these two concepts to polarimetric interferometric sAR (Pol-InsAR) forest height estimation *** application makes use of volume decorrelation,which is also a function of *** both the spatial decorrelation and volume decorrelation are considered to determine Pol-InsAR critical and maximal effective *** various decorrelation effects are *** the calculation formula of Pol-InsAR maximal effective baseline are presented and compared to that of *** validation,RVoG-based and PolsARpro-based simulation data and DLR EsAR data are *** concept of Pol-InsAR maximal effective baseline is of practical significance in selection of Pol-InsAR image pairs as well as in the design of further Pol-InsAR systems.

关键词： Pol-InsAR maximal baseline forest height estimation