检索结果-内蒙古大学图书馆

International Conference on computer Communications and Networks

作者： Kaimin Wei Deze Zeng Song Guo Ke Xu State Key Laboratory of Software Development Environment Beihang University China School of Computer Science and Engineering University of Aizu Japan

In Delay Tolerant Networks (DTNs), the connections between mobile nodes are intermittent and constant end-to-end paths rarely exist. In order to achieve high delivery ratio, most existing DTN routing algorithms favor the "multi-hop forwarding" fashion where a message can be forwarded by multiple relay nodes in the hope that one of the employed relay nodes can deliver the message to the destination node. Since aggressively employing relay nodes may incur intolerable delivery cost to resource-constrained mobile nodes in DTNs, it is significant to design a cost-efficient routing protocol that can achieves high delivery ratio. In this paper, we first utilize the small-world feature to limit the maximum forwarding hops in a reasonable way and then propose a greedy relay node selection strategy. A cost-efficient social-aware forwarding algorithm called TBSF (the-best-so-far) is then presented. Extensive simulations on real mobility traces are conducted to evaluate the performance of TBSF. Simulation results show that, in comparison with several well-known routing algorithms, TBSF can achieve high performance in terms of delivery ratio and delivery delay while with much lower delivery cost.

关键词： DTNs TBSF delivery ratio

来源：评论

学校读者我要写书评

暂无评论

A precise approach to tracking dim-small targets using spectral fingerprint features

引用

Frontiers of computer science 2012年第5期6卷 527-536页

作者： Hao SHENG Chao LI Yuanxin OUYANG Zhang XIONG School of Computer Science and Engineering Beihang UniversityBeijing 100191China Research Institute of Beihang University in Shenzhen Shenzhen 518057China State Key Laboratory of Software Development Environment Beihang UniversityBeijing 100191China

A precise method for accurately tracking dim- small targets, based on spectral fingerprint is proposed where traditional full color tracking seems impossible. A fingerprint model is presented to adequately extract spectral features. By creating a multidimensional feature space and extending the limited RGB information to the hyperspectral information, the improved precise tracking model based on a nonparamet- ric kernel density estimator is built using the probability his- togram of spectral features. A layered particle filter algorithm for spectral tracking is presented to avoid the object jumping abruptly. Finally, experiments are conducted that show that the tracking algorithm with spectral fingerprint features is ac- curate, fast, and robust. It meets the needs of dim-small target tracking adequately.

关键词： dim-small target precise tracking spectral fingerprint features LPF algorithm for spectral tracking

来源：评论

学校读者我要写书评

暂无评论

A efficient and robust method for complexly faulted horizon reconstruction based on meshes cutting and interpolating

A efficient and robust method for complexly faulted horizon ...

引用

2012 IEEE International Conference on computer science and Automation engineering, CSAE 2012

作者： Li, Jigang Meng, Xianhai Li, Yufeng Yang, Qin State Key Laboratory of Software Development Environment School of Computer Science and Engineering Beihang University Beijing China

ISBN: (纸本)9781467300865

3d-geological modeling is a means of improving data interpretation through visualization, as well as a way to generate support for numerical simulations of complex phenomena. Reconstructing horizons from scattered point clouds is an omnipresent task in 3d-geological modeling. As the geometrical representation of faults network is not watertight in the process of modeling for the reason of efficiency, the reconstructed horizons cut by the fault network are often topological inconsistency. A robust and efficient method to reconstruct topologically and geometrically consistent horizons based on meshes cutting and Discrete Smooth Interpolation (DSI) is proposed to tackle this problem. By representing the faults network with both triangular and rectangular mesh, and under the guide of macro spatial topology, the initial continuous mesh of a horizon could be cut by the faults network efficiently and robustly. DSI is adopted to further adjust the non-manifold mesh of horizon to their proper position while keeping the topological contact relation unchanged. The result shows that the horizons reconstructed are consistent. It indicates that the method can solve the inconsistency of the horizons caused by the inconsistency of the faults network. © 2012 IEEE.

关键词： Interpolation

来源：评论

学校读者我要写书评

暂无评论

3D structural geological modeling based on morphing field 1

引用

International Conference on Information engineering and Applications, IEA 2011

作者： Xianhai, Meng Jigang, Li Qin, Yang State Key Laboratory of Software Development Environment School of Computer Science and Engineering BeiHang University Beijing 100191 China

ISBN: (数字)9781447123866

ISBN: (纸本)9781447123859

Strata are continuous surface by sediment, which form fractured and discontinuous geological layers during strata moving. In 3D structural geological modeling, how to describe fractured geological layers well and truly is a complicated problem. Now most software such as RCRC's 3D Earth Modeling, Petrel's advanced 3D Reservoir Modeling, ROXAR's RMS, T-Surf's GOCAD, create strata by user interactive editing during 3D geological modeling. Only little commercial software such as DGI's Earth Vision Modeling System realizes the function of creating discontinuous strata by strata point set and faults directly. At present, we can't yet search correlative algorithm in open literature. © 2012 Springer-Verlag London Limited.

关键词： Geology

来源：评论

学校读者我要写书评

暂无评论

A formal semantics for program debugging

引用

science China(Information sciences) 2012年第1期55卷 133-148页

作者： LI Wei1&LI Ning1,2 1state key lab.ratory of software development environment,school of computer science and engineering,Beihang University,Beijing 100191,China 2China Ship Research and development Academy,Beijing 100192,China 1. State Key Laboratory of Software Development Environment School of Computer Science and Engineering Beihang University Beijing 100191 China2. China Ship Research and Development Academy Beijing 100192 China

This work aims to build a semantic framework for automated debugging.A debugging process consists of tracing,locating,and fixing processes *** first two processes are accomplished by a tracing procedure and a locating procedure,*** tracing procedure reproduces the execution of the failed test case with well-designed data structures and saves necessary information for locating *** locating procedure will use the information obtained from the tracing procedure to locate ill-designed statements and to generate a system of fix-equations,whose solution will be used to fix the bugs.A structural operational semantics is given to define the functions of the tracing and locating *** of them are proved to *** main task of fixing process is to solve the *** turns out that for a given failed test case,there exist four types of fix-equations and three dierent solutions:1)The bug is solvable,i.e.,there exists a solution of the system of fix-equations,and the program can be repaired.2)There exists a structural design error in the program,i.e.,the system of fix-equations generated at each round of the locating procedure is solvable,but a new bug will arise when the old bug is being fixed.3)There exists a logical design error,and the system of fix-equations is not solvable.

关键词： debugging operational semantics failed test case fix-equations

来源：评论

学校读者我要写书评

暂无评论

Chinese personal name recognition using N-gram model and rules

Chinese personal name recognition using N-gram model and rul...

引用

2012 7th International Conference on Computing and Convergence Technology (ICCIT, ICEI and ICACT), ICCCT 2012

作者： Lin, Chen Hui, Zhang Zhen'an, Li State Key Laboratory of Software Development Environment Beihang University School of Computer Science and Engineering 100191 Beijing China

ISBN: (纸本)9788994364216

Chinese personal name recognition plays an important role in Chinese word segmentation and it's difficult to recognize whether a sequence of characters is a name or not for its complexity. This paper presents a new algorithm based on N-gram model and recognition rules to resolve this problem. In order to increase efficiency and accuracy, we also build several dictionaries such as a surname dictionary and a person-name dictionary. Experiments on different corpora show that the improved tokenizer using this algorithm performs stably and achieves more than 10 percent word segmentation accuracy increase than the original one. Averagely the improved tokenizer's recall rate and accuracy rate are both over 92%. © 2012 AICIT.

关键词： Computational linguistics

来源：评论

学校读者我要写书评

暂无评论

Reliability-aware automatic composition approach for web services

引用

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 lab.ratory of software development environment,Beihang University,Beijing 100191,China 2 school of computer science and engineering,Beihang University,Beijing 100191,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 availab.e 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 availab.e 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

来源：评论

学校读者我要写书评

暂无评论

When sparsity meets noise in collab.rative filtering

引用

14th Asia Pacific Web Technology Conference, APWeb 2012

作者： Hu, Biyun Li, Zhoujun Chao, Wenhan State Key Laboratory of Software Development Environment Beihang University China School of Computer Science and Engineering Beihang University Beijing China

ISBN: (纸本)9783642292521

Traditionally, it is often assumed that data sparsity is a big problem of user-based collab.rative filtering algorithm. However, the analysis is based only on data quantity without considering data quality, which is an important characteristic of data, sparse high quality data may be good for the algorithm, thus, the analysis is one-sided. In this paper, the effects of training ratings with different levels of sparsity on recommendation quality are first investigated on a real world dataset. Preliminary experimental results show that data sparsity can have positive effects on both recommendation accuracy and coverage. Next, the measurement of data noise is introduced. Then, taking data noise into consideration, the effects of data sparsity on the recommendation quality of the algorithm are re-evaluated. Experimental results show that if sparsity implies high data quality (low noise), then sparsity is good for both recommendation accuracy and coverage. This result has shown that the traditional analysis about the effect of data sparsity is one-sided, and has the implication that recommendation quality can be improved substantially by choosing high quality data. © 2012 Springer-Verlag Berlin Heidelberg.

关键词： Collab.rative filtering

来源：评论

学校读者我要写书评

暂无评论

Independent domination on tree convex bipartite graphs

Independent domination on tree convex bipartite graphs

引用

6th International Frontiers of Algorithmics Workshop, FAW 2012 and 8th International Conference on Algorithmic Aspects of Information and Management, AAIM 2012

作者： Song, Yu Liu, Tian Xu, Ke Key Laboratory of High Confidence Software Technologies School of Electronic Engineering and Computer Science Peking University Beijing 100871 China National Lab. of Software Development Environment Beihang University Beijing 100191 China

ISBN: (纸本)9783642296994

An independent dominating set in a graph is a subset of vertices, such that every vertex outside this subset has a neighbor in this subset (dominating), and the induced subgraph of this subset contains no edge (independent). It was known that finding the minimum independent dominating set (Independent Domination) is -complete on bipartite graphs, but tractable on convex bipartite graphs. A bipartite graph is called tree convex, if there is a tree defined on one part of the vertices, such that for every vertex in another part, the neighborhood of this vertex is a connected subtree. A convex bipartite graph is just a tree convex one where the tree is a path. We find that the sum of larger-than-two degrees of the tree is a key quantity to classify the computational complexity of independent domination on tree convex bipartite graphs. That is, when the sum is bounded by a constant, the problem is tractable, but when the sum is unbounded, and even when the maximum degree of the tree is bounded, the problem is -complete. © 2012 Springer-Verlag.

关键词： Forestry

来源：评论

学校读者我要写书评

暂无评论

Complexity of synthesis of composite service with correctness guarantee

引用

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 lab.ratory of software development environment, Beihang University Beijing 100191, China 2school of Mathematics and System science, Beihang University, Beijing 100191, China 3school of computer science and engineering, Beihang University, Beijing 100191, 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

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：