检索结果-南通市图书馆

science china(Information sciences) 2012年第2期55卷 312-321页

作者： HE You1,HU LiFang1,2,GUAN Xin1,3,DENG Yong4 & HAN DeQiang5 1Research Institute of Information Fusion,Naval Aeronautical and Astronautical university,Yantai 264001,china 2Navy Armament Academy,beijing 102249,china 3The Institute of Electronic science and engineering,National university of Defense Technology,Changsha 410073,china 4school of electronics and Information Technology,Shanghai Jiao Tong university,Shanghai 200240,china 5Institute of Integrated Automation,Xi'an Jiaotong university,Xi'an 710049,china Research Institute of Information Fusion Naval Aeronautical and Astronautical University Navy Armament Academy The Institute of Electronic science and engineering National University of Defense Technology

There is doubt about Dempster's rule of combination because of counter-intuitive results when dealing with conflict information in intelligent ***,many modified combination rules have been presented in the literature on multi-source information fusion and reasoning with ***,the issue of identifying conflict among evidence has been ignored.A new parameter measuring conflict evidence called the conflict distance parameter is defined to determine whether there are conflicts in evidence based on the analysis of existing conflict *** the same time,a decisive rule,which a reasonable conflict measure function should satisfy,is put ***,an analysis of two typical counter-intuitive situations is given,showing that the new parameter can not only satisfy the decisive rule,but can also attain the same effect as a two-dimensional measure when deciding whether to use the Dempster's rule of combination,and can exceed its effect when deciding whether to use Dezert-Smarandache theory.

关键词： conflict evidence Dezert-Smarandache theory Dempster’s rule of combination information fusion uncertainty

THE ML FREQUENCY TRACKING ALGORITHM FOR OFDM SYSTEMS BASED ON PILOT SYMBOLS AND DECISION DATA

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

THE ML FREQUENCY TRACKING ALGORITHM FOR OFDM SYSTEMS BASED O...

A Hybrid FE-BI Method Using in Antenna Radiation Analysis

IEEE 2005 International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications

作者： Laibo Zheng 1,2, Weijun Cheng3, Jiandong Hu1, Dongfeng Yuan2 1. Telecommunication engineering school, beijing university of Posts and Telecommunications Postbox 92, beijing university of Posts and Telecommunications, beijing P.R. china, 100876 2. Information science and engineering school, Shandong university Information science and engineering school, Shandong university, Jinan P.R. china, 250100 3. Department of electronics, peking university Department of electronics, peking university, beijing, P.R. china, 100871

pilot symbols inserted into OFDM symbols for channel estimation can be used to track the carrier frequency. The main merit of this method is that good performance of frequency tracking can be obtained

关键词： domain THE ML FREQUENCY TRACKING ALGORITHM FOR OFDM SYSTEMS BASED ON PILOT SYMBOLS AND DECISION DATA

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

A Hybrid FE-BI Method Using in Antenna Radiation Analysis

A novel model-free approach for reconstruction of time-delayed gene regulatory networks

The 8th International Symposium on Antennas,Propagation and EM Theory（ISAPE2008）

作者： Huilin HU 1,Yunhua TAN 2,Bocheng ZHU,Lezhu ZHOU Electromagnetic Field and Microwave Lab,Electronic engineering and computer science school,peking university 100871 beijing PRC

A hybrid method which combines the finite element and boundary integral methods (FE-BI) for simulating electromagnetic radiation of antennas is *** method not only can correctly model the boundary conditions,but also can deal with complex geometry and material *** matrixes formed from FEM are sparse,and the boundary integral method is applied to reduce the simulation complexities and memory *** accuracy and efficiency of the method are verified by Bow-tie Antennas.

关键词： Hybrid method,antennas,electromagnetic radiation,finite element method (FEM),finite element and boundary integral method (FE-BI)

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

中国科学：生命科学英文版 2006年第2期49卷 190-200页

作者： JIANG Wei1,2, LI Xia1,2,3,4, GUO Zheng1,2,3, LI Chuanxing1, WANG Lihong1 & RAO Shaoqi1,5 1. Department of Bioinformatics, Harbin Medical university, Harbin 150086, china 2. Department of computer science, Harbin Institute of Technology, Harbin 150080, china 3. school of Life science and Technology, Tongji university, Shanghai 200092, china 4. Biomedical engineering Institute, Capital university of Medical sciences, beijing 100054, china 5. Departments of Cardiovascular Medicine and Molecular Cardiology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA Department of Bioinformatics Harbin Medical University Harbin 150086 China

Reconstruction of genetic networks is one of the key scientific challenges in functional genomics. This paper describes a novel approach for addressing the regulatory dependencies be-tween genes whose activities can be delayed by multiple units of time. The aim of the proposed ap-proach termed TdGRN (time-delayed gene regulatory networking) is to reversely engineer the dy-namic mechanisms of gene regulations, which is realized by identifying the time-delayed gene regu-lations through supervised decision-tree analysis of the newly designed time-delayed gene expres-sion matrix, derived from the original time-series microarray data. A permutation technique is used to determine the statistical classification threshold of a tree, from which a gene regulatory rule(s) is ex-tracted. The proposed TdGRN is a model-free approach that attempts to learn the underlying regula-tory rules without relying on any model assumptions. Compared with model-based approaches, it has several significant advantages: it requires neither any arbitrary threshold for discretization of gene transcriptional values nor the definition of the number of regulators (k). We have applied this novel method to the publicly available data for budding yeast cell cycling. The numerical results demonstrate that most of the identified time-delayed gene regulations have current biological knowledge supports.

关键词： gene regulatory networks, time delayed, decision tree.

Method for tumor recognition with short dynamic PET images:Theory and simulation study

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2009年第1期19卷 73-77页

作者： Huiting Qiao a,Jing Bai a,Yingmao Chen b,Jiahe Tianb a Department of Biomedical engineering,school of Medicine,Tsinghua university,beijing 100084,china b Department of Nuclear Medicine,General Hospital of PLA,beijing 100853,china Department of Biomedical engineering School of Medicine Tsinghua University Beijing 100084 China Department of Nuclear Medicine General Hospital of PLA Beijing 100853 China

A new method was provided in this paper to recognize tumor in PET images automatically and reduce the waiting time of *** on the unsupervised clustering algorithm(ISODATA),this method diagnoses tumor with short dynamic PET *** theoretical basis of this method is that the metabolic characteristics of different tissues,represented by time-activity curve in the region of interest,are *** computer program was developed and validated using simulated dynamic PET data with small tumor in *** study shows that this method could recognize tumor with the short dynamic PET data in 10 min successfully,and this method was not sensitive to initial cluster center.

关键词： Dynamic PET Clustering algorithm Tumor recognition Simulation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

螺旋线行波管注-波互作用三维粒子模拟

微波学报 2010年第S2期26卷 105-108页

作者：熊晓燕李明之北京大学信息科学技术学院北京100871

结合时域有限差分方法和粒子模拟方法,开发了螺旋线行波管的三维注-波互作用粒子模拟程序。从最基本的电磁场运动规律和力学规律出发,利用高速计算机直接求解完整的麦克斯韦方程组和洛伦兹方程,完成了对C波段螺旋线行波管的注-波互作用... 详细信息

结合时域有限差分方法和粒子模拟方法,开发了螺旋线行波管的三维注-波互作用粒子模拟程序。从最基本的电磁场运动规律和力学规律出发,利用高速计算机直接求解完整的麦克斯韦方程组和洛伦兹方程,完成了对C波段螺旋线行波管的注-波互作用的模拟计算,得到了电子的相位和空间分布以及管子的功率、增益等电性能参量,验证了程序的正确性,为后期优化和设计奠定了基础。

关键词：螺旋线行波管注-波互作用时域有限差分方法三维粒子模拟

LoI:Effcient relevance evaluation and filtering for distributed simulation

在线全文

学校读者我要写书评

暂无评论

science in china(Series F) 2009年第3期52卷 470-489页

作者： ZHOU Zhong1,2 & WU Wei1,2 1 State Key Laboratory of Virtual Reality Technology and Systems, Beihang university, beijing 100191, china 2 school of computer science and engineering, Beihang university, beijing 100191, china

In large-scale distributed simulation, thousands of objects keep moving and interacting in a virtual environment, which produces a mass of messages. High level architecture （HLA） is the prevailing standard for modeling and simulation. It specifies two publish-subscribe mechanisms for message filtering： class-based and value-based. However, the two mechanisms can only judge whether a message is relevant to a subscriber or not. Lacking of the ability to evaluate the relevance, all relevant messages are delivered with the same priority even when congestion occurs. It significantly limits the scalability and performance of distributed simulation. Aiming to solve the relevance evaluation problem, speed up message filtering, and filter more unnecessary messages, a new relevance evaluation mechanism Layer of Interest （Lol） was proposed by this paper. Lol defines a relevance classifier based on the impact of spatial distance on receiving attributes and attribute values. An adaptive publish-subscribe scheme was built on the basis of Loh This scheme can abandon most irrelevant messages directly. Run-time infrastructure （RTI） can also apply congestion control by reducing the frequency of sending or receiving object messages based on each objects＇ Loh The experiment results verify the efficiency of message filtering and RTI congestion control.

关键词： distributed simulation high level architecture (HLA) relevance evaluation layer of interest (Lol) run-time infrastructure (RTI)

在线全文

学校读者我要写书评

暂无评论

遗传关联向量机高光谱影像分类

上海交通大学学报 2011年第10期45卷 1516-1520页

作者：董超田联房赵慧洁华南理工大学自动化科学与工程学院广州510641 北京航空航天大学仪器科学与光电工程学院北京100191

基于高光谱影像临近波段相关性高,直接在高维空间分类并非最优,并且使用交叉验证进行分类器参数寻优过程繁琐,提出了遗传关联向量机(GA-RVM)高光谱影像分类算法,使用遗传算法搜索面向关联向量机(RVM)的最优参数和特征子空间,消除冗余信... 详细信息

基于高光谱影像临近波段相关性高,直接在高维空间分类并非最优,并且使用交叉验证进行分类器参数寻优过程繁琐,提出了遗传关联向量机(GA-RVM)高光谱影像分类算法,使用遗传算法搜索面向关联向量机(RVM)的最优参数和特征子空间,消除冗余信息,简化参数优化过程.实验环节验证了GA-RVM算法的有效性,剔除约50%冗余波段后,总体分类精度提高3%,对难分地物改进尤为明显,其中混分最严重的2种大豆精度提高了8%.

关键词：高光谱分类关联向量机遗传算法

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

在线全文

学校读者我要写书评

暂无评论

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 university, Room B209, Building of Medical science, beijing 100084, china b school of Information Technologies, university of Sydney, NSW 2006, Australia c Department of Electronic and Information engineering, Hong Kong Polytechnic university, 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 Information 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)