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Polynomial analysis of canopy spectra and biochemical component content inversion

Science china Earth Sciences 2005年第10期48卷 1780-1791页

作者： YAN Chunyan1, LIU Qiang1, NIU Zheng1, WANG Jihua2. HUANG Wenjiang2.& LIU Liangyun 2.1. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University, Beijing 100101, china 2. national engineering research center for information technology in agriculture, Beijing {2., china State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing china national engineering {2. center for information technology in agriculture Beijing china

A polynomial expression model was developed in this paper to describe directional canopy spectra, and the decomposition of the polynomial expression was used as a tool for re-trieving biochemical component content from canopy multi-angle spectra. First, the basic formula of the polynomial expression was introduced and the physical meaning of its terms and coeffi-cients was discussed. Based on this analysis, a complete polynomial expression model and its decomposition method were given. By decomposing the canopy spectra simulated with SAILH model, it shows that the polynomial expression can not only fit well the canopy spectra, but also show the contribution of every order scattering to the whole reflectance. Taking the first scattering coefficients a10 and a01 for example, the test results show that the polynomial coefficients reflect very well the hot spot phenomenon and the effects of viewing angles, LAI and leaf inclination angle on canopy spectra. By coupling the polynomial expression with leaf model PROSPECT, a canopy biochemical component content inversion model was given. In the simulated test, the canopy multi-angle spectra were simulated by two different models, SAILH and 4-SCALE re-spectively, then the biochemical component content was retrieved by inverting the coupled polynomial expression + PROSPECT model. Results of the simulated test are promising, and when applying the algorithm to measured corn canopy multi-angle spectra, we also get relatively accurate chlorophyll content. It shows that the polynomial analysis provides a new method to get biochemical component content independent of any specific canopy model.

关键词： polynomial expression, canopy spectra, decomposition, biochemical component content, inversion.

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A formal model of fair exchange protocols

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Science in china(Series F) 2005年第4期48卷 499-512页

作者： QING Sihan1,2.3 & LI Gaicheng1,2.3 1. engineering research {2. for information Security technology, Institute of Software, Chinese Aca- demy of Sciences, Beijing 100080, china 2. Beijing Zhongke Ansheng Corporation of information technology, Beijing 100080, china 3. Graduate School of the Chinese Academy of Sciences, Beijing 100039, china 1. engineering research {2. for information Security technology Institute of Software Chinese Academy of Sciences 100080 Beijing China 2. Beijing Zhongke Ansheng Corporation of information technology 100080 Beijing China 3. Graduate School of the Chinese Academy of Sciences 100039 Beijing China

Based on the study of existing fair exchange protocols, this paper sets up an accurate formal model by stepwise refinement. In the process of refinement an unreliable channel is employed to simulate an attack behavior. The model provides a novel formal definition of exchanged items, and presents the formal goals for fairness, accountability, etc., reflecting the inherent requirements for fair exchange protocols across-the-board. In order to check, prove, and design fair exchange protocols effectively and efficiently, the model puts forward a novel property of abuse-freeness which applies to all fair exchange protocols, gives a formal definition for trust strand of the third party, and presents general criteria of designing a secure and effective fair exchange protocol. Taking a typical fair exchange protocol as an example, this paper presents the analysis steps of fair exchange protocols appealing to our model. An unknown attack is uncovered. The analysis reveals the process of a complete attack, discovering deeper reasons for causing an attack. Finally, we modify the flawed protocol and the revised protocol ensures the desirable properties.

关键词： events local causal relation local temporal relation global relation exchanged item security goals.

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Electric-stimulus rate encoding algorithm of Mandarin tonal information in cochlear implant

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Progress in Natural Science:Materials International 2006年第12期16卷 1315-1321页

作者： GUAN Tian~1, GONG Qin~1 and YE Datian~2.*(1. Department of Biomedical engineering, Tsinghua University, Beijing 100084, china 2. {2. center of Biomedical engineering, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, china) [a]Department of Biomedical engineering Tsinghua University Beijing China [b]research center of Biomedical {2. Graduate School at Shenzhen Tsinghua University Shenzhen China

The modern multi-channel cochlear implants usually extract and encode the temporal envelope cues. This kind of algorithms can hardly satisfy the users who speak tonal languages, such as Mandarin. Many studies have tried to enhance the recognition ability of Mandarin through encoding tonal information and made suggestions to frequency-modulate the fixed pulse-rate carrier with the extracted tonal information based on the rate-pitch theory in electric hearing. However, how to encode and deliver the tonal information such as F_0by changing electric-stimulus rate has not got further study in clinical electric-stimulus mode. The present paper focuses on this matter by piecewise calculating the appreciable electric-stimulus rates. Then an electric-stimulus encoding algorithm of Mandarin tone is brought forward and testified through acoustic simulations. Such conclusion can be drawn that this algorithm of electric-stimulus rate could convey tonal information well and help to enhance the Mandarin speech recognition ability.

关键词： cochlear implant tone fundamental frequency electric-stimulus rate.

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Formal analysis and design of multi-party fair exchange protocols

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Science in china(Series F) 2006年第2期49卷 155-174页

作者： QING Sihan1,2.3 & LI Gaicheng1,3 1. engineering research {2. for information Security technology, Institute of Software, Chinese Academy of Sciences, Beijing 100080, china 2. Beijing Zhongke Ansheng Corporation of information technology, Beijing 100080, china 3. Graduate School of the Chinese Academy of Sciences, Beijing 100039, china 1. engineering research {2. for information Security technology Institute of Software Chinese Academy of Sciences Beijing 100080 China 2. Beijing Zhongke Ansheng Corporation of information technology Beijing 100080 China 3. Graduate School of the Chinese Academy of Sciences Beijing 100039 China

Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately,

关键词： fair exchange logical protocol formal model security requirement.

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Identifying heavy hitters in high-speed network monitoring

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Science china(information Sciences) 2010年第3期53卷 659-676页

作者： ZHANG Yu1, FANG BinXing1,2.& ZHANG YongZheng2.1research center of Computer Network and {2. Security technology, Harbin Institute of technology, Harbin 150001, china 2.0} center of {2. Security, Institute of Computing technology, Chinese Academy of Sciences, Beijing 100190, china 1. research center of Computer Network and {2. Security technology Harbin Institute of Technology Harbin 150001 China2. Research Center of Information Security Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

Identifying heavy hitters in a network traffic stream is important for a variety of network applications ranging from traffic engineering to anomaly detection such as detection of denial-of-service attacks. Existing methods generally examine newly arriving items in the stream, perform a small number of operations using a small amount of memory, and still provide guarantees on the identifying accuracy. In high-speed network monitoring, the update speed per item is extremely critical. However, so far as we know, there are no identifying algorithms which can provide constant update time (O(1)) in a weighted data stream. In this paper, we present an algorithm named Weighted Lossy Counting (WLC) which is able to identify heavy hitters in a high-speed weighted data stream with constant update time. WLC employs a novel efficient partially ordered data structure which is able to provide a fast per-item update speed while keeping the memory cost relatively low. We compare WLC with state-of-the-art algorithms for finding heavy hitters in real traffic traces. The experimental results show that WLC performs well in accuracy (recall, precision and average relative error) as other algorithms; moreover it has a much higher update speed at the cost of relatively larger memory space used. A theoretical worst-case memory bound of WLC is also derived in this paper; however, experiments with long real traffic traces show that WLC requires much less space than the theoretical bound in practice.

关键词： network traffic monitoring heavy hitter weighted data streams

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Analysis of crack propagation in concrete structures with structural information entropy

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Science china(Technological Sciences) 2010年第7期53卷 1943-1948页

作者： BAO TengFei1’2. PENG Yan1’2. CONG PeiJiang1’2.& WANG JiaLin1’2.1 State Key Laboratory of Hydrology-Water Resources and Hydraulic engineering, Hohai University, Nanjing 2.002., china 2.{2. engineering research center ofWater Resources Efficient Utilization and engineering Safety, Hohai University, Nanjing 2.002., china 1. State Key Laboratory of Hydrology-Water Resources and Hydraulic engineering Hohai University Nanjing 210024 China2. National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University Nanjing 210024 China

The propagation of cracks in concrete structures causes energy dissipation and release, and also causes energy redistribution in the structures. Entropy can characterize the energy redistribution. To investigate the relation between the propagation of cracks and the entropy in concrete structures, cracked concrete structures are treated as dissipative structures. Structural information entropy is defined for concrete structures. A compact tension test is conducted. Meanwhile, numerical simulations are also carried out. Both the test and numerical simulation results show that the structural information entropy in the structures can characterize the propagation of cracks in concrete structures.

关键词： crack entropy concrete sun

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A property-based attestation protocol for TCM

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Science china(information Sciences) 2010年第3期53卷 454-464页

作者： FENG DengGuo1,2.& QIN Yu1,2.1State Key Laboratory of information Security, Institute of Software, Chinese Academy of Science, Beijing 100190, china 2.2. engineering research center of information Security, Beijing 100190, china 1. State Key Laboratory of information Security Institute of Software Chinese Academy of Science Beijing 100190 China2. National Engineering Research Center of Information Security Beijing 100190 China

This paper presents a property attestation protocol for the security chip TCM (trusted cryptographic module) via analyzing the problems of the current property attestation, which is built on the property attestation model with the online trust third party. In the protocol the prover utilizes the zero-knowledge proof by the attribute certificates, configuration commitment and TCM signature, and attests its configuration and status which are compliant with the declarative security property. The protocol is characterized by shorter signature length and lower computations. The security of the protocol is proved at the random oracle model. The protocol can help extend application and improve standard for security chip TCM, and it also has practical value and immediate significance.

关键词： trust computing trust cryptographic module (TCM) property attestation signature of knowl- edge configuration commitment

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Integrating MODFLOW and GIS technologies for assessing impacts of irrigation management and groundwater use in the Hetao Irrigation District,Yellow River basin

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Science china(Technological Sciences) 2009年第11期52卷 3257-3263页

作者： XU Xu1,2. HUANG GuanHua1,2.& QU ZhongYi3 1 center for agriculture Water {2., china Agricultural University, Beijing 100083, china 2.Chinese-Israeli International center for {2. and Training in agriculture, china Agricultural University, Beijing 100083, china 3 Water Conservancy and Civil engineering College, Inner Mongolia Agricultural University, Hohhot 010018, china 1. center for agriculture Water {2. China Agricultural University Beijing 100083 China 2. Chinese-Israeli International center for {2. and Training in agriculture China Agricultural University Beijing 100083 China 3. Water Conservancy and Civil engineering College Inner Mongolia Agricultural University Hohhot 010018 China

Due to severe water scarcity, water resources used in agricultural sector have been reduced markedly in Hetao irrigation district. Application of water-saving practices (WSPs) is required for the sustainable agricultural development. The human activities including WSPs and increase of groundwater abstraction can lower down the groundwater table, which is helpful to the salinity control. Meanwhile, an excessively large groundwater table depth may result in negative impact on crop growth and fragile ecological environment. In this paper, the Jiefangzha irrigation system in Hetao irrigation district was selected as a typical area, a groundwater flow model based on ArcInfo Geographic information System (GIS) was developed and implemented to quantify the effect of human activities on the groundwater system in this area. The preand post-processing of model data was performed efficiently by using the available GIS tools. The time-variant data in boundary conditions was further edited in Microsoft Excel with programs of Visual Basic for Application (VBA). The model was calibrated and validated with independent data sets. Application of the model indicated that it can well describe the effect of human activities on groundwater dynamics in Jiefangzha irrigation system.

关键词： groundwater flow modeling MODFLOW GIS water-saving practices irrigation district

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Design,analysis and control of hybrid excited doubly salient stator-permanent-magnet motor

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Science china(Technological Sciences) 2010年第1期53卷 188-199页

作者： ZHU XiaoYong1,2.& CHENG Ming1 1 engineering research {2. for Motion Control of MOE,School of Electrical engineering,Southeast University,Nanjing 2.0096,china 2.School of Electrical and information engineering,Jiangsu University,Zhenjiang 2.2.13,china 1. engineering research {2. for Motion Control of MOE School of Electrical Engineering Southeast University Nanjing 210096 China2. School of Electrical and Information Engineering Jiangsu University Zhenjiang 212013 China

In this paper,a new hybrid excited doubly salient stator-permanent-magnet motor is proposed,where both permanent magnets and DC field windings are located in the *** theory,the mathematical model and design method of the motor are *** corresponding output power equation and the relationship between the flux control capability and the extended speed range are deduced in *** using an efficient "one-step" three-dimensional(3D) finite element method,the electromagnetic performances are analyzed,in which the leakage flux outside the stator circumference and end-effect are taken into *** on the operation principle of the motor,the control strategy and scheme are developed and implemented *** experimental results and finite element analysis show that the proposed motor not only maintains the advantages of doubly salient permanent magnet motors,but also offers high energy efficiency over a wide speed range,which makes the motor an interesting candidate for electric vehicles.

关键词： stator permanent magnet motor hybrid excitation doubly salient finite element method flux weakening control

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Channel-aware and queue-aware joint-layer resource optimization for cognitive radio networks

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Science china(information Sciences) 2010年第12期53卷 2576-2583页

作者： GUO KunQi 1,2.SUN LiXin 1,LI Yong 2.& JIA ShiLou 3 1 School of Computer Science and Telecommunication engineering,Jiangsu University,Zhenjiang 2.2.13,china 2.{2. center for Wireless Communication,Shanghai Institute of Microsystem and information technology,Chinese Academy of Sciences,Shanghai 2.0050,china 3 Communication {2. center,Harbin Institute of technology,Harbin 150001,china 1. School of Computer Science and Telecommunication engineering Jiangsu University Zhenjiang 212013 China2. Research Center for Wireless Communication Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 China3. Communication Research Center Harbin Institute of Technology Harbin 150001 China

An optimization model is derived to maximize the utilization efficiency of the idle channels of primary users(PU) in cognitive radio *** the optimization model,Lyapunov optimization method is used to allocate the idle channels of PU to secondary user(SU) most *** time distribution of the idle channels of PU is predicted by a low-pass time *** algorithm is proposed to implement the optimization *** algorithm is efficient because of using a greedy selection *** efficiency of the algorithm is demonstrated by mathematic analyses and simulation results.

关键词： cognitive radio networks Lyapunov optimization resource utilization primary user secondary user

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