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A Novel Low-bit-rate Speech Coding Based on Decomposition of the Pitch-cycle Waveform of the Linear Predictive Residual

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通信学报 1998年第5期19卷 39-44页

作者： Bao ChangchunAssociate professor of information engineering, {2. Polytechnic university, Ph.D, CIE senior member ({4. of electronic engineering, {2. Polytechnic university, {2. 10002.) Fan ChangxinProfessor of information Engineerin 北京工业大学电子工程系北京西安电子科技大学信息科学所陕西西安

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关键词：线性估计语音编码失量量化分解节圈波形

Monitoring the Cultivated Slope Land in the Three Gorges Reservoir Area Based on Remote Sensing and GIS

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Wuhan university Journal of Natural Sciences 2006年第4期11卷 915-921页

作者： ZHOU Jieming1, ZHOU Qigang 2. 3 ,HUANG Zhiqin 2. 3, 4.1. The Faculty of Geography and Resources Science, Sichuan Normal university, Chengdu 610066, Sichuan, {2. 2. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 61004., Sichuan, {2. 3. Graduate university of the Chinese Academy of Sciences, {4. 10004., {2. 4. information Center of Land and Resources department of Sichuan Province, Chengdu 61004., Sichuan, {2. The Faculty of Geography Resources Science Sichuan Normal University 610066 Chengdu Sichuan China Institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China Graduate university of the Chinese Academy of Sciences 100049 Beijing China information Center of Land Resources department of Sichuan Province 610041 Chengdu Sichuan China

By means of combining auto-extraction with manual interpretation, the current distribution information about cultivated land is obtained. The distribution information of 1992.is extracted from the dynamic polygons of 2.02. The monitoring mini-system of the cultivated slope land is established. In the system, detailed surveys, focused on the resources of cultivated slope land, are carried out. The results indicate that the area of the cultivated slope land is very large. Meanwhile, there are lots of cultivated steep slopes with gradient above 35°. The areas of steep land cultivated had been slowly reduced from 1992.to 2.02. At the same time, the pressures of returning farm land to forestry are great in all counties. The conflicts between population growth, insufficient grain supply and stagnant economic development sharpen increasingly. It is inevitable to improve the {2. structure.

关键词： slope land cultivated remote sensing geography information system (GIS) the pressure of returning farm land to forestry Three Gorges Reservoir Area

Computer simulation on reliability of retention index with FDG-PET and optimization of dual-time-point imaging protocol

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Progress in Natural Science:Materials International 2008年第8期18卷 931-937页

作者： Rui Jia a, Jing Bai a,*, Lingfeng Wenb,c, Dagan Fengb,c a department of Biomedical engineering, Tsinghua {2., Room B2.9, Building of Medical Science, beijing 100084. {4. b School of information Technologies, {2. of Sydney, NSW 2.06, Australia c department of electronic and information engineering, Hong Kong Polytechnic {2., Hong Kong department of Biomedical engineering Tsinghua University Room B209 Building of Medical Science Beijing 100084 China School of information Technologies University of Sydney NSW 2006 Australia department of electronic and {2. engineering Hong Kong Polytechnic University Hong Kong

The inherent noise in positron emission tomography (PET) leads to the instability of quantitative indicators, which may affect the diagnostic accuracy for differentiating malignant and benign lesions in the management of lung cancer. In this paper, the reliability of retention index (RI) is systematically investigated by using computer simulation for the dual-time-point imaging protocol. The area under the receiver operating characteristic (ROC) curve is used to evaluate the optimal protocol. Results demonstrate that the reliability of RI is affected by several factors including noise level, lesion type, and imaging schedule. The RIs with small absolute values suffer from worse reliability than those larger ones. The results of ROC curves show that over delayed second scan cannot help to improve the diagnostic performance further, while an early first scan is expected. The method of optimization based on ROC analysis can be easily extended to comprise as many lesions as possible.

关键词： Reliability Retention index PET (positron emission tomography) Simulation ROC (receiver operating characteristic)

Influence of Yb^(3+) concentration on the upconversion luminescence of oxyfluoride material doped with Er^(3+)

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 310-314页

作者： ZHAO SuLing1,XU Zheng1,WANG LiHui2.& S. Wageh3 1 Institute of Optoelectronic Technology,Key Laboratory of Luminescence and Optical information ({2. Jiaotong university),Ministry of Education,{2. 10004.,china 2.department of Physics,Chinese People’s Public Security university,{2. 100038,china 3 Physics & engineering Mathematics department Faculty of electronic engineering Menufiya university,Menouf 32.52.Egypt 1. Institute of Optoelectronic Technology Key Laboratory of Luminescence and Optical Information (Beijing Jiaotong University) Ministry of Education Beijing 100044 China2. Department of Physics Chinese People’s Public Security University Beijing 100038 China3. Physics & Engineering Mathematics Department Faculty of Electronic Engineering Menufiya University Menouf 32952 Egypt

In this paper,a new upconversion luminescent material co-doped with Erbium and Ytterbium is reported. The upconversion luminescence transition routes and related properties are studied. The results show that the absorption and emission intensities under excitation of 980 nm laser increase with the increase of the Yb3+ concentration. The red emission is stronger than the green emission. The energy transfer process plays an important role in the upconversion mechanism.

关键词： upconversion luminescence Er3+ Yb3+

The normal numbers of the fuzzy systems and their classes

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Science china(information Sciences) 2010年第11期53卷 2215-2229页

作者： LI HongXing1,3, YUAN XueHai1, WANG JiaYin2.& LI YuCheng3 1Faculty of electronic information and Electrical {2., Dalian university of Technology, Dalian 11602.4} {4. 2.chool of Mathematical Sciences, beijing Normal university, beijing 100875, {4. 3department of Automation, North {4. university of Technology, beijing 10014., {4. 1. Faculty of electronic information and Electrical {2. Dalian University of Technology Dalian 116024 China3. Department of Automation North China University of Technology Beijing 100144 China2. School of Mathematical Sciences Beijing Normal University Beijing 100875 China

R-fuzzy set is defined in this paper, which is regarded as the generalization of the Zadeh fuzzy set. By means of CRI method, some fuzzy systems are constructed by suitably using several kinds of R-fuzzy sets as fuzzy inference antecedents, such as interpolation fuzzy system, Bernstein fuzzy system, Lagrange fuzzy system and Hermite fuzzy system. A notion of the normal number of the fuzzy system is defined here, we have shown that all fuzzy systems are able to be classified as three classes such as the normal fuzzy systems, the regular fuzzy systems and the singular fuzzy systems under the significance of the normal numbers of fuzzy systems. Finally, the generalized Bernstein polynomial is obtained by constructing Bernstein fuzzy system, it is proved that the generalized Bernstein polynomial is uniformly convergent in C[a,b] under a weaker condition, and it is pointed out that there exist generalized Bernstein polynomials to be not convergent in C[a,b] by use of constructing a counterexample.

关键词： R-fuzzy set fuzzy system the normal number of fuzzy system universal approximation property for fuzzy system

Detection and parameter estimation of multicomponent LFM signal based on the fractional Fourier transform

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Science in china(Series F) 2004年第2期47卷 184-198页

作者： QI Lin1, 2. TAO Ran1, ZHOU Siyong1 & WANG Yue1 1. department of electronic {2., beijing Institute of Technology, beijing 100081, china 2. School of information {2., Zhengzhou university, Zhengzhou 4.0052. china Correspondence should be addressed to QI Lin (email: qilin@***) 1. department of electronic {2. Beijing Institute of Technology 100081 Beijing China 2. School of information engineering Zhengzhou University 450052 Zhengzhou China

This paper presents a new method for the detection and parameter estimation of multicomponent LFM signals based on the fractional Fourier transform. For the optimization in the fractional Fourier domain, an algorithm based on Quasi-Newton method is proposed which consists of two steps of searching, leading to a reduction in computation without loss of accuracy. And for multicomponent signals, we further propose a signal separation technique in the fractional Fourier domain which can effectively suppress the interferences on the detection of the weak components brought by the stronger components. The statistical analysis of the estimate errors is also performed which perfects the method theoretically, and finally, simulation results are provided to show the validity of our method.

关键词： LFM signal parameter estimation fractional Fourier transform.

Preparation of nanocrystalline BaTiO_3 ceramics

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Science china(Technological Sciences) 2009年第6期52卷 1730-1734页

作者： DENG XiangYun1,2.LI DeJun1,LI JianBao2.WANG XiaoHui3 & LI LongTu3 1 college of Physics and electronic {2.,Tianjin Normal university,Tianjin 300387,{4. 2.Materials and Chemical engineering Institute,Key Laboratory for Hainan Advantage Resources and Applied Technology in Chemical engineering Material of Ministry of Education,Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti,Hainan university,Haikou 5702.8,{4. 3 department of Materials Science and engineering,Tsinghua university,{12. 100084.{4. college of Physics and electronic {2. Tianjin Normal University Tianjin 300387 China Materials and Chemical engineering Institute Key Laboratory for Hainan Advantage Resources and Applied Technology in Chemical Engineering Material of Ministry of Education Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti Hainan University Haikou 570228 China department of Materials Science and engineering Tsinghua University Beijing 100084 China

The high-dense nanocrystalline BaTiO3(BT)ceramics with grain size smaller than 100nm have been successfully prepared by the two step sintering and the spark plasma sintering(SPS)*** successive transitions in nanograin BT ceramics from rhombohedral to orthorhombic,tetragonal and cubic transitions,similar to those in coarse BT ceramics,were revealed by in-situ temperature dependent Raman *** multiphase coexistence and the diffused phase transition character were demonstrated in the 8nm nanocrystalline BT ceramics.

关键词： nanocrystalline BaTiO3 ceramics preparation microstructure size effect

Mapping and overlapping based carrier frequency searching technique for rapid GNSS long PN-code acquisition

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Science china(information Sciences) 2010年第12期53卷 2642-2652页

作者： LI Hong ,LU MingQuan & FENG ZhenMing department of electronic {2.,Tsinghua university,{4. 100084.china 1. department of electronic {2. Tsinghua University Beijing 100084 China

In global navigation satellite systems(GNSS),because of the long period and high chip rate of long pseudo-noise(PN) code,the rapid acquisition is hard to *** speed up search process,in the paper,a mapping and overlapping based carrier frequency searching technique is *** mapping incoming signals of the same interval to different carrier frequency cells and overlapping together the mapped incoming signals that correspond to the same code phase,the technique reduces the number of the cells to be *** effect of the technique on detection and mean acquisition time performance is *** is shown that the technique reduces the cells to be searched and shortens mean acquisition time at the expense of degrading detection *** technique is fit to the previously published acquisition methods and is capable of improving their mean acquisition time *** and simulation results validate the analysis.

关键词： carrier frequency cells mapping overlapping acquisition performance

Study on internal quantum efficiency of blue InGaN multiple-quantum-well with an InGaN underneath layer

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Science china(Technological Sciences) 2010年第2期53卷 306-308页

作者： WANG JiaXing, WANG Lai, ZHAO Wei, ZOU Xiang & LUO Yi National Laboratory for information Science and Technology/State Key Laboratory on Integrated Optoelectronics, {2. of electronic {4., Tsinghua university, beijing 100084. china 1. National Laboratory for information Science and Technology/State Key Laboratory on Integrated Optoelectronics Department of Electronic Engineering Tsinghua University Beijing 100084 China

Blue InGaN multiple-quantum-well (MQW) samples with different InxGa1-xN (x=0.01–0.04. underneath layers (ULs) were grown by metal organic vapor phase epitaxy (MOVPE). Temperature dependent photoluminescence showed that the InGaN UL can improve the internal quantum efficiency (IQE) of MQW effectively due to strain release. And a maximum IQE of 50% was obtained when the thickness and In content of the InGaN UL were 60 nm and 0.01, respectively. Furthermore, the larger In content or thickness of the InGaN UL makes the IQE lower. Arrhenius fit to the experiment data showed that the IQE fall was mainly caused by the quantity increase of the nonradiative recombination centers, which was believed related to the accumulated stress in InGaN ULs.

关键词： InGaN underneath layer (UL) multiple-quantum-well (MQW) internal quantum efficiency (IQE) Arrhenius formula