检索结果-内蒙古大学图书馆

Conference on Computer Vision and Pattern Recognition (CVPR)

作者： P. Nillius J.-O. Eklundh Computational Vision & Active Perception Laboratory (CVAP) Department of Numerical Analysis and Computing Science Royal Institute of Technology Stockholm Sweden

The aim of this paper is to find the best representation for the appearance of surfaces with Lambertian reflectance under varying illumination. Previous work using principal component analysis (PCA) found the best sub-space to represent all images of an object under a varying point light source. We extend this to images from any illumination distribution. Specifically we calculate the bases for all configurations of a point plus ambient light source and two point light sources, as well as from a database of captured real world illumination. We also reformulate the optimization criterion used in PCA. The resulting basis, we believe has higher representability and is better for analyzing images of shaded objects. The different bases are compared on a database of images to test the representability.

关键词： Lighting Light sources Computer vision Principal component analysis Power harmonic filters Reflectivity Image databases Image analysis Jacobian matrices Low pass filters

来源：评论

学校读者我要写书评

暂无评论

A game theoretic model for management of mobile sensors

A game theoretic model for management of mobile sensors

引用

International Conference on Information Fusion

作者： L. Ronnie M. Johansson Ning Xiong H.I. Christensen Centre for autonomous systems Department of Numerical Analysis and Computer Science Royal Institute of Technology Stockholm Sweden

ISBN: (纸本)0972184449

This paper suggests a framework for multi-sensor multi-target tracking with mobile sensors. Sensors negotiate over which targets to track (possibly sharing targets to benefit from data fusion technology) using a game theory based algorithm. Sensors' preferences over negotiation offers are articulated with individual utility functions which encompass both information gain and directional derivative. An approach to consider terrain effects on mobile sensors is also explained. Simulation results show that the negotiation algorithm has interesting advantages compared to a greedy algorithm that seeks to optimise information gain without consideration to derivatives. We notice that the negotiation procedure forces sensors to share targets, while improving robustness to sensor failure. Sensors also tend to proactively reconsider their target assignments for long-term improved information gain.

关键词： Game theory Sensor systems Target tracking Robustness Resource management Control systems Decision support systems Centralized control Distributed control Intelligent sensors

来源：评论

学校读者我要写书评

暂无评论

A strong inapproximability gap for a generalization of minimum bisection

A strong inapproximability gap for a generalization of minim...

引用

Annual IEEE Conference on Computational Complexity

作者： J. Holmerin S. Khot Department of Numerical Analysis and Computer Science Royal Institute of Technology Stockholm Sweden Department of Computer Science Princeton University Princeton NJ USA

As a problem with similar properties to minimum bisection, we consider the following: given a homogeneous system of linear equations over Z/sub 2/, with exactly k variables in each equation, find a balanced assignment that minimizes the number of satisfied equations. A balanced assignment is one which contains an equal number of 0s and 1s. When k=2, this is the minimum bisection problem. We consider the case k=3. In this case, it is NP-complete to determine whether the object function is zero [U. Feige, (2003)], so the problem is not approximable at all. However, we prove that it is NP-hard to determine distinguish between the cases that all but a fraction /spl epsi/ of the equations can be satisfied and that at least a fraction 1/4-/spl epsi/ of all equations cannot be satisfied. A similar result for minimum bisection would imply that the problem is hard to approximate within any constant. For the problem of approximating the maximum number of equations satisfied by a balanced assignment, this implies that the problem is NP-hard to approximate within 4/3-/spl epsi/, for any /spl epsi/>0.

关键词： Equations Computer science Approximation algorithms numerical analysis Computational complexity

来源：评论

学校读者我要写书评

暂无评论

Different ways of evaluating a Swedish grammar checker 3

Different ways of evaluating a Swedish grammar checker

引用

3rd International Conference on Language Resources and Evaluation, LREC 2002

作者： Domeij, Rickard Knutsson, Ola Eklundh, Kerstin Severinson Department of Numerical Analysis and Computer Science Royal Institute of Technology StockholmSE-10044 Sweden

Three different ways of evaluating a Swedish grammar checker are presented and discussed in this article. The first evaluation concerns measuring the program's detection capacity on five text genres. The measures (precision and recall) are often used in evaluating grammar checkers. However, in order to test and improve the usability of grammar checking software, they need to be complemented with user-oriented methods. Consequently, the second and the third evaluations presented in the article both involve users. The second evaluation focuses on user reactions to grammar error presentations, especially with regard to false alarms and erroneous error identification. The third and last evaluation focuses on problems in supporting users' cognitive revision processes. It also examines user motives behind choosing to correct or not to correct problems highlighted by the program. Advantages and disadvantages of the different evaluation methods are discussed.

关键词： Software testing

来源：评论

学校读者我要写书评

暂无评论

Collaboration between writer and reviewer through change representation tools 35

Collaboration between writer and reviewer through change rep...

引用

35th Annual Hawaii International Conference on System sciences, HICSS 2002

作者： Kim, Hee-Cheol Eklundh, K.S. Department of Numerical Analysis and Computer Science Royal Institute of Technology StockholmS-100 44 Sweden

ISBN: (纸本)0769514359

Change representation concerns how changes of text are presented in writing tools. Change representation in collaborative writing can play an important role for the collaborators' understanding of changes of text. We have conducted a laboratory study where 10 pairs of a writer and a reviewer produced argumentative letters by using the change representation functions. We have also set different conditions in the experimental task: (a) two ways of representing changes, indication and display, and (b) two collaboration models, the writer- and the reviewer-initiative models. A primary source of the data was obtained though interviews with the participants. The paper reports their experience of collaboration in writing with change representation tools, relevant design conclusions, and lessons learned from the study. © 2002 IEEE.

关键词： Visualization

来源：评论

学校读者我要写书评

暂无评论

From comments to dialogues: A study of asynchronous dialogue processes as part of collaborative reviewing on the Web 35

From comments to dialogues: A study of asynchronous dialogue...

引用

35th Annual Hawaii International Conference on System sciences, HICSS 2002

作者： Kim, Hee-Cheol Department of Numerical Analysis and Computer Science Royal Institute of Technology StockholmS-100 44 Sweden

ISBN: (纸本)0769514359

When working together on a common document, collaborators frequently share and discuss their ideas about further revisions. Collaborative writing might, therefore, be thought of as a process of negotiating what changes to make among co-authors. The World-Wide Web is an easily accessible infrastructure to facilitate such a communication process over documents. This paper explores the dialogues formed by comments exchanged among co-authors in a Web-based collaboration tool, Col·laboració. A case study was performed where a small group of writers discussed and revised a common document, using this system. The author demonstrates how these dialogues are structured and what properties they have in relation to the context of collaborative reviewing processes. The analysis of dialogues is also used to reflect on design issues with regard to dialogue support and comment categorization. © 2002 IEEE.

关键词： Websites

来源：评论

学校读者我要写书评

暂无评论

Improved inapproximability results for Vertex Cover on κ-uniform hypergraphs

引用

29th International Colloquium on Automata, Languages, and Programming, ICALP 2002

作者： Holmerin, Jonas Department of Numerical Analysis and Computer Science Royal Institute of Technology SE-100 44 Stockholm Sweden

ISBN: (纸本)3540438645

We prove that Minimum Vertex Cover on κ-uniform hypergraphs is NP-hard to approximate within Ω(κ1-Ε). The result follows by a new reduction and a PCP characterization of NP by Håstad and Khot [11]. We also give an alternate construction of a PCP with the required properties. We also show that Minimum Vertex Cover on 3-uniform hypergraphs is NP-hard to approximate within 3/2 - Ε. Of independent interest may be a 3 query PCP for NP with perfect completeness where answers are from a domain of size d and where the soundness is 2/d. © 2002 Springer-Verlag Berlin Heidelberg.

关键词： Graph theory

来源：评论

学校读者我要写书评

暂无评论

Anomalous slowing down in the metastable liquid of hard spheres

引用

Physical Review E 2002年第3期65卷 032501-032501页

作者： M. Dzugutov Department of Numerical Analysis and Computer Science Royal Institute of Technology SE–100 44 Stockholm Sweden

It is demonstrated that a straightforward extension of the Arrhenius law accurately describes diffusion in the thermodynamically stable liquid of hard spheres. A sharp negative deviation from this behavior is observed as the liquid is compressed beyond its stability limit. This dynamical anomaly can be compared with the nonlinear slowing down characteristic of the supercooled dynamics regime in liquids with continuous interaction. It is suggested that the observed dynamical transition is caused by long-time decomposition of the configuration space. This interpretation is corroborated by the observation of characteristic anomalies in the geometry of a particle trajectory in the metastable domain.

关键词： Spheres

来源：评论

学校读者我要写书评

暂无评论

Why neuronal dynamics should control synaptic learning rules

Why neuronal dynamics should control synaptic learning rules

引用

15th Annual Neural Information Processing Systems Conference, NIPS 2001

作者： Tegnér, Jesper Kepecs, Ádam Dept.. of Numerical Analysis and Computing Science Stockholm Bioinformatics Center Royal Institute for Technology S-10044 Stockholm Sweden Volen Center for Complex Systems Brandeis University WalthamMA 02454 United States

ISBN: (纸本)0262042088

Hebbian learning rules are generally formulated as static rules. Under changing condition (e.g. neuromodulation, input statistics) most rules are sensitive to parameters. In particular, recent work lias focused 011 two different, formulations of spike-t iming-dependent plasticity rules. Additive STT)P [1] is remarkably versatile but also very fragile, whereas multiplicative ST'DP [2. 3] is more robust but lacks attractive features such as synaptic compet it ion and rate stabilization. Here we address the problem of robustness in the additive STDP rule. We derive an adaptive control scheme, where the learning function is under fast dynamic control by postsynaptic activity t o stabilize learning under a variety of conditions. Such a control scheme can be implemented using known biophysical mechanisms of synapses. We show that this adaptive rule makes the additive STDP more robust. Finally, we give an example how meta plasticity of the adaptive rule can be used to guide STDP into different, type of learning regimes.

关键词： Neural networks

来源：评论

学校读者我要写书评

暂无评论

Collaboration between writer and reviewer through change representation tools

Collaboration between writer and reviewer through change rep...

引用

Annual Hawaii International Conference on System sciences (HICSS)

作者： Hee-Cheol Kim K.S. Eklundh Department of Numerical Analysis and Computer Science The Royal Institute of Technology Stockholm Sweden

ISBN: (纸本)0769514359

关键词： Collaborative tools Writing Collaboration Collaborative work numerical analysis Computer science Laboratories Displays Visualization History

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：