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Filterless Photosensors with Intrinsic Color Perception and Flexibility

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Chemical Research in Chinese Universities 2024年第5期40卷 894-900页

作者： ZHOU Hongtao XU beihang ZHENG Xinjia GONG Jinchao ZHANG Kaitong HE Yonglin Key Laboratory of Advanced Light Conversion Materials and Biophotonics School of Chemistry and Life ResourcesRenmin University of ChinaBeijing100872P.R.China school of Mathematics Renmin University of ChinaBeijing100872P.R.China

Sensing materials possessing intrinsic color perception are indispensable prerequisites for the development of filterless photosensors,which could eliminate the need for complex device designs and avoid color distortion in *** materials are constrained by complex processing methods and limited ***,a color-photosensitive array based on ionic liquid with selective photothermal conversion(ILSPC)has been developed for intrinsic color *** on the selective absorption,photothermal conversion,and thermosensitivity of ILSPC,a photo-thermo-electric sensing system has been ***,the versatility of the two algorithms has been validated in color reconstruction and electrical signal *** an exploration,the photosensitive array showcases promising color recognition capabilities,potentially propelling the evolution of flexible photosensors.

关键词： Ionic liquid Filterless Intrinsic color perception Selective photothermal conversion Photosensitive array

Adaptive control for autonomous rendezvous of spacecraft on elliptical orbit

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Acta Mechanica Sinica 2009年第4期25卷 539-545页

作者： Shan Lu Shijie Xu school of Astronautics, beihang university,1.01.1 beijing, china school of Astronautics Beihang University 100191 Beijing China

A strategy for spacecraft autonomous rendezvous on an elliptical orbit in situation of no orbit information is developed. Lawden equation is used to describe relative motion of two spacecraft. Then an adaptive gain factor is introduced, and an adaptive control law for auton- omous rendezvous on the elliptical orbit is designed using Lyapunov approach. The relative motion is proved to be ultimately bounded under this control law, and the final relative position error can achieve the expected magnitude. Simulation results indicate that the adaptive control law can realize autonomous rendezvous on the elliptical orbit with relative state information only.

关键词： Autonomous rendezvous Elliptical orbit Lyapunov approach Adaptive control Gain factor

Reliability-aware automatic composition approach for web services

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Science china(Information Sciences) 2012年第4期55卷 921-937页

作者： LI Mu 1,2,LI Bo 1,2 & HUAI JinPeng 1,2 1 State Key Laboratory of software Development Environment,beihang university,beijing 1.01.1.china 2 school of Computer Science and Engineering,beihang university,beijing 1.01.1.china 1. State Key Laboratory of software Development Environment Beihang University Beijing 100191 China2. School of Computer Science and Engineering Beihang University Beijing 100191 China

In this paper,we study the reliability-aware synthesis problem for composing available services automatically and guaranteeing that the composed result satisfies the specification,such as temporal constraints of functionality and reliability,centered on a synthesis model for mediator of web services composition (CSM).This approach focuses on handling attributes and state relations,and permitting users and services to operate over them,i.e.,read /write their data values and compare them according to a dense state *** show that the reliability-aware synthesis problem for the specification is EXPTIME-complete and we give an exponential-time algorithm (CSM-NSA) which for a given formula ψ and a synthesis model,synthesizes available services in the library satisfying ψ over the synthesis model (if they exist) or responds with "not satisfiable" (otherwise).The specification ψ is a fragment of PCTL (probabilistic computation tree logic),obtained from "ordinary" CTL (computation tree logic) by replacing the EX,AX,EU and AU operation with their quantitative counterparts X >p,X =1,U >p,and U =1,*** opposed to NSA,we provide a more effective algorithm to replace the NSA algorithm called CSM-HSA (heuristic synthesis algorithm).Though HSA is an incomplete algorithm,the answer is *** experiments show that the HSA algorithm solves the problem of reliability-aware service synthesis effectively and efficiently.

关键词： reliability web services synthesis problem synthesis model heuristic algorithm

Simulation of three-dimensional nonideal MHD flow at high magnetic Reynolds number

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中国科学：技术科学英文版 2010年第1期53卷 206-212页

作者： LU HaoYu1 & Lee ChunHian2 1 school of Astronautics,beihang university,beijing 1.01.1.china 2 National Laboratory for Computational Fluid Dynamics,beihang university,beijing 1.01.1.china 1. school of Astronautics Beihang University Beijing 100191 China2. National Laboratory for Computational Fluid Dynamics Beihang University Beijing 100191 China

A conservative TVD scheme is adopted to solve the equations governing the three-dimensional flow of a nonideal compressible conducting fluid in a magnetic *** eight-wave equations for magnetohydrodynamics(MHD) are proved to be a non-strict hyperbolic system,therefore it is difficult to develop its *** developed a new set of equations which cannot be numerically simulated by conservative TVD scheme directly due to its non-conservative form.A conservative TVD scheme augmented with a new set of eigenvectors is proposed in the *** validate this scheme,1-D MHD shock tube,unsteady MHD Rayleigh problem and steady MHD Hartmann problem for different flow conditions are *** simulated results are in good agreement with the existing analytical *** this scheme can be used to effectively simulate high-conductivity fluids such as cosmic MHD problem and hypersonic MHD flow over a blunt body,etc.

关键词： magnetohydrodynamics(MHD) numerical simulation TVD MHD Rayleigh flow MHD Hartmann flow

An approach to detecting abnormal vehicle events in complex factors over highway surveillance video

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Science china(Technological Sciences) 2008年第S2期51卷 199-208页

作者： SHENG Hao1,XIONG Zhang1,WENG JingNong2 & WEI Qi1 1 College of Computer,beihang university,beijing 1.01.1.china 2 College of software,beihang university,beijing 1.01.1.china College of Computer Beihang University Beijing 100191 China College of software Beihang University Beijing 100191 China

The detection of abnormal vehicle events is a research hotspot in the analysis of highway surveillance *** of the complex factors,which include different conditions of weather,illumination,noise and so on,vehicle's feature extraction and abnormity detection become *** paper proposes a Fast Constrained Delaunay Triangulation(FCDT) algorithm to replace complicated segmentation algorithms for multi-feature *** on the video frames segmented by FCDT,an improved algorithm is presented to estimate background *** the estimation,a multi-feature eigenvector is generated by Principal Component Analysis(PCA) in accordance with the static and motional features extracted through locating and tracking each *** abnormity detection,adaptive detection modeling of vehicle events(ADMVE) is presented,for which a semi-supervised Mixture of Gaussian Hidden Markov Model(MGHMM) is trained with the multi-feature eigenvectors from each video *** normal model is developed by supervised mode with manual labeling,and becomes more accurate via iterated *** abnormal models are trained through the adapted Bayesian learning with unsupervised *** paper also presents experiments using real video sequence to verify the proposed method.

关键词： background estimation abnormity detection adaptive detection modeling a semi-supervised MGHMM

Complexity of synthesis of composite service with correctness guarantee

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Science china(Information Sciences) 2012年第3期55卷 638-649页

作者： DENG Ting1,2 , HUAI JinPeng1,3 & WO TianYu1,3 1State Key Laboratory of software Development Environment, beihang university beijing 1.01.1, china 2school of Mathematics and System Science, beihang university, beijing 1.01.1, china 3school of Computer Science and Engineering, beihang university, beijing 1.01.1, china 1. State Key Laboratory of software Development Environment Beihang University Beijing 100191 China2. School of Mathematics and System Science Beihang University Beijing 100191 China3. School of Computer Science and Engineering Beihang University Beijing 100191 China

How to compose existing web services automatically and to guarantee the correctness of the design (e.g. temporal constraints specified by temporal logic LTL, CTL or CTL*) is an important and challenging problem in web services. Most existing approaches use the process in conventional software development of design, verification, analysis and correction to guarantee the correctness of composite services, which makes the composition process both complex and time-consuming. In this paper, we focus on the synthesis problem of composite service; that is, for a given set of services and correctness constraint specified by CTL or CTL* formula, a composite service is automatically constructed which guarantees that the correctness is ensured. We prove that the synthesis problem for CTL and CTL* are complete for EXPTIME and 2EXPTIME, respectively. Moreover, for the case of synthesis failure, we discuss the problem of how to disable outputs of environment (i.e. users or services) reasonably to make synthesis successful, which are also proved complete for EXPTIME and 2EXPTIME for CTL and CTL*, respectively.

关键词： business protocol composite service synthesis environment branching temporal logic

3D building modeling,organization and application in digital city system

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中国科学：技术科学英文版 2010年第S1期53卷 134-142页

作者： YANG Xue 1,WENG JingNong 1,2,XIA YuBin 2,WU Lun 3 & SUI ZhengWei 3 1 College of software,beihang university,beijing 1.01.1.china 2 College of Computer,beihang university,beijing 1.01.1.china 3 Institute of Remote Sensing and GIS,Peking university,beijing 100871,china beihang Univ Coll Software Beijing 100191 Peoples R China beihang Univ Coll Comp Beijing 100191 Peoples R China Peking Univ Inst Remote Sensing & GIS Beijing 100871 Peoples R China

The real world is a three-dimensional(3D)space requiring that 3D geospatial information applications be developed in alignment with the observer’s visual and perceptive ***,3D building model data are required in a wide range of areas such as urban planning,environmental protection,real estate management and emergency *** the same time,the development of Web service[LU1]technologies allows the possibility of the widely distributed 3D geospatial data on the web.3D city building model with its related information is an important part in the construction of a digital city system,and has become a staple resource on the web *** view of the hierarchical representation of a 3D building model,an abstract of a 3D building model based on structure details is studied,and a novel representation approach named 3D transparent building hierarchical model is presented in this *** approach fully uses both the existing 3D modeling technologies and CAD constructing mapping *** the spatial relationship description,structural components inside a building can be represented and integrated as hierarchical models in a unified 3D *** addition,based on the characteristics of the 3D building model data,a service-oriented architecture and Web service technologies for 3D city building models are *** aim of the approach is that 3D city building models can be used as a kind of data resource service on the web,and can also exist independently in various different web applications.

关键词： 3D modeling 3D transparent building hierarchical models china Star web services

A numerical simulation on the infrared radiation of hot exhausting nozzles with a coupled flow and heat transfer model

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Science china(Technological Sciences) 2010年第10期53卷 2699-2707页

作者： HU HaiYang1 & WANG Qiang2 1 china Academy of Aerospace Aerodynamics, beijing 100074, china 2 school of Jet Propulsion, beihang university, beijing 1.01.1, china 1. china Academy of Aerospace Aerodynamics Beijing 100074 China2. School of Jet Propulsion Beihang University Beijing 100191 China

A coupled model among flow field,solid temperature,species concentration and gas radiation,which was based on statistical narrow-band correlated-k model,was employed to predict the infrared radiations from hot exhausting nozzles. The parameters of narrow-band model were deduced from HITEMP line-by-line database. Several methods to increase computational efficiency and to save computational resources were employed,thus all the complicated computations could be operated on a personal computer. The predictions for three cases have been conducted to validate the accuracy of the methods mentioned above,including the temperature distribution of a water-cooling nozzle in rocket engines,the carbon dioxide absorptivity at the wavelength of 4.3 micron and the infrared radiation of a cylindrical furnace. Finally,the aerothermodynamic and infrared characteristics of two nozzles were predicted. It was shown that the infrared radiation intensity of chevron ejecting nozzle were obviously smaller than that of common axisymmetric convergent-divergent nozzle.

关键词： infrared radiation numerical simulation exhausting nozzles coupled model

Adaptive neuro fuzzy inference system for classification of water quality status

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Journal of Environmental Sciences 2010年第12期22卷 1891-1896页

作者： Han Yan,Zhihong Zou,Huiwen Wang school of Economics and Management,beihang university,beijing 1.01.1.china [a] school of Economics Management Beihang University Beijing 100191 China

An adaptive neuro fuzzy inference system was used for classifying water quality status of river. It applied several physical and inorganic chemical indicators including dissolved oxygen, chemical oxygen demand, and ammonia-nitrogen. A data set （nine weeks, total 845 observations） was collected from 100 monitoring stations in all major river basins in china and used for training and validating the model. Up to 89.59% of the data could be correctly classified using this model. Such performance was more competitive when compared with artificial neural networks. It is applicable in evaluation and classification of water quality status.

关键词： adaptive neuro fuzzy inference system artificial neural networks water quality status classification