用于3D模型检索的扩展距离球面调和表达

使用光线投射方法对3D模型定义了一个对应的球函数--扩展距离球函数,然后引入了球面调和分析方法,构造了一种对于平移、缩放和旋转变换具有不变性的特征向量,并用于基于形状的3D模型检索中.与基于向径方法结合,提高了检索的效果,扩大了应用范围.     

Unsupervised Single-Channel Music Source Separation by Average Harmonic Structure Modeling

Source separation of musical signals is an appealing but difficult problem, especially in the single-channel case. In this paper, an unsupervised single-channel music source separation algorithm based on average harmonic structure modeling is proposed. Under the assumption of playing in narrow pitch ranges, different harmonic instrumental sources in a piece of music often have different but stable harmonic structures; thus, sources can be characterized uniquely by harmonic structure models. Given the number of instrumental sources, the proposed algorithm learns these models directly from the mixed signal by clustering the harmonic structures extracted from different frames. The corresponding sources are then extracted from the mixed signal using the models. Experiments on several mixed signals, including synthesized instrumental sources, real instrumental sources, and singing voices, show that this algorithm outperforms the general nonnegative matrix factorization (NMF)-based source separation algorithm, and yields good subjective listening quality. As a side effect, this algorithm estimates the pitches of the harmonic instrumental sources. The number of concurrent sounds in each frame is also computed, which is a difficult task for general multipitch estimation (MPE) algorithms.     

Representation for knot-tying tasks

The learning from observation (LFO) paradigm has been widely applied in various types of robot systems. It helps reduce the work of the programmer. However, the applications of available systems are limited to manipulation of rigid objects. Manipulation of deformable objects is rarely considered, because it is difficult to design a method for representing states of deformable objects and operations against them. Furthermore, too many operations are possible on them. In this paper, we choose knot tying as a case study for manipulating deformable objects, because the knot theory is available and the types of operations possible in knot tying are limited. We propose a knot planning from observation (KPO) paradigm, a KPO theory, and a KPO system.     

A Representation Theorem for MV-algebras

An MV-pair is a pair (B,G) where B is a Boolean algebra and G is a subgroup of the automorphism group of B satisfying certain conditions. Let ~ _G be the equivalence relation on B naturally associated with G. We prove that for every MV-pair (B,G), the effect algebra B/ ~ _G is an MV-effect algebra. Moreover, for every MV-effect algebra M there is an MV-pair (B,G) such that M is isomorphic to B/ ~ _G . This research is supported by grant VEGA G-1/3025/06 of MŠ SR, Slovakia and by the Science and Technology Assistance Agency under the contract No. APVT-51-032002.     

适于点绘制的图形表示方法的研究

在基于点的图形绘制技术中,作为绘制基本元素的点不是数学上无意义的点,它有位置、形状、大小等属性,如何基于点有效地表示图形将影响图形绘制的效果。论文研究了基于点的图形表示方法——单纯基于点的表示、圆球表示和表面足迹表示,重点讨论了足迹表示法的关键问题——足迹大小的求解,提出了一种基于协方差分析的表面足迹的求解方法,结果表明这种方法是有效的。     

Representation theory for default logic

Default logic can be regarded as a mechanism to represent families of belief sets of a reasoning agent. As such, it is inherently second-order. In this paper, we study the problem of representability of a family of theories as the set of extensions of a default theory. We give a complete solution to the problem of representability by means of default theories with finite set of defaults, and by means of normal default theories. We obtain partial results on representability by arbitrary (infinite, non-normal) default theories. We construct examples of denumerable families of non-including theories that are not representable. We also study the concept of equivalence between default theories. This revised version was published online in June 2006 with corrections to the Cover Date.     

Labeling Schemes for Tree Representation

This paper deals with compact label-based representations for trees. Consider an n-node undirected connected graph G with a predefined numbering on the ports of each node. The all-ports tree labeling ℒ _all gives each node v of G a label containing the port numbers of all the tree edges incident to v. The upward tree labeling ℒ _up labels each node v by the number of the port leading from v to its parent in the tree. Our measure of interest is the worst case and total length of the labels used by the scheme, denoted M _up (T) and S _up (T) for ℒ _up and M _all (T) and S _all (T) for ℒ _all . The problem studied in this paper is the following: Given a graph G and a predefined port labeling for it, with the ports of each node v numbered by 0,…,deg (v)−1, select a rooted spanning tree for G minimizing (one of) these measures. We show that the problem is polynomial for M _up (T), S _up (T) and S _all (T) but NP-hard for M _all (T) (even for 3-regular planar graphs). We show that for every graph G and port labeling there exists a spanning tree T for which S _up (T)=O(nlog log n). We give a tight bound of O(n) in the cases of complete graphs with arbitrary labeling and arbitrary graphs with symmetric port labeling. We conclude by discussing some applications for our tree representation schemes. A preliminary version of this paper has appeared in the proceedings of the 7th International Workshop on Distributed Computing (IWDC), Kharagpur, India, December 27–30, 2005, as part of Cohen, R. et al.: Labeling schemes for tree representation. In: Proceedings of 7th International Workshop on Distributed Computing (IWDC), Lecture Notes of Computer Science, vol. 3741, pp. 13–24 (2005). R. Cohen supported by the Pacific Theaters Foundation. P. Fraigniaud and D. Ilcinkas supported by the project “PairAPair” of the ACI Masses de Données, the project “Fragile” of the ACI Sécurité et Informatique, and by the project “Grand Large” of INRIA. A. Korman supported in part by an Aly Kaufman fellowship. D. Peleg supported in part by a grant from the Israel Science Foundation.     

Time-Scale Atoms Chains for Transients Detection in Audio Signals

This paper presents a novel approach for the extraction of the transients content of audio signals, usually represented as superposition of stationary, transient, and stochastic components. The proposed model exploits the predictable and peculiar time-scale behavior of transients by modeling them as superposition of suitable wavelet atoms. These latter allow to predict transients information even at scales where the tonal component is dominant. In this way it is possible to avoid, if required, the pre-analysis of the tonal component. Extensive experimental results show that the proposed model achieves good performances with a moderate computational effort and without any user's dependence.      

SCSI子系统中间层多启动互连多路径I/O的存储方式的研究

面对当前应用对现代存储的高性能以及可用性、可靠性的新的要求,在Multi—Initiator—Uni—Port的基础之上提出了SCSI中间层多启动互连多路径I／O的存储方式．它能够在Multi—Initiator—Uni—Port的连接中对同一个Target端口采用不同的I／O路径进行存储,减少了由于单路径I／O传输错误导致系统单点失效的可能性,增强了存储系统的可用性和可靠性;同时,这种存储方式还能够很好地平衡系统的I／O负载,提高系统的吞吐率,提供比传统单路径更好的传输性能．在Linux2．4内核中的SCSI子系统的基础之上实现了这种存储方式,向系统屏蔽了SCSI子系统中的设备具体细节,并且不依赖于SCSI上层的实现,减少了对系统内核的资源占有率,提高了SCSI底层的执行效率．分析了SCSI中间层多启动互连多路径I／O的存储方式的原理,并且将iSCSI的体系结构应用到它的模拟测试中,得到了R—R路径选择分配策略的性能临界点,取得了令人满意的结果．     

Harmonic Embeddings for Linear Shape Analysis

We present a novel representation of shape for closed contours in ℝ² or for compact surfaces in ℝ³ explicitly designed to possess a linear structure. This greatly simplifies linear operations such as averaging, principal component analysis or differentiation in the space of shapes when compared to more common embedding choices such as the signed distance representation linked to the nonlinear Eikonal equation. The specific choice of implicit linear representation explored in this article is the class of harmonic functions over an annulus containing the contour. The idea is to represent the contour as closely as possible by the zero level set of a harmonic function, thereby linking our representation to the linear Laplace equation. We note that this is a local represenation within the space of closed curves as such harmonic functions can generally be defined only over a neighborhood of the embedded curve. We also make no claim that this is the only choice or even the optimal choice within the class of possible linear implicit representations. Instead, our intent is to show how linear analysis of shape is greatly simplified (and sensible) when such a linear representation is employed in hopes to inspire new ideas and additional research into this type of linear implicit representations for curves. We conclude by showing an application for which our particular choice of harmonic representation is ideally suited.     

Knowledge Representation for Model Management Systems

This paper examines the concept of a model management system, what its functions are, and how they are to be achieved in a decision support context. The central issue is model representation which involves knowledge representation and knowledge management within a database environment. The model abstraction structure is introduced as a vehicle for model representation which supports both heuristic and deterministic inferencing as well as the conceptual/external schema notion familiar to database management. The model abstraction is seen as a special instance of the frame construct in artificial intelligence. Model management systems are characterized as frame-systems and a database implementation of this approach is described.     

多边形的隐函数表示法

文章提出了一种方法,用一个隐函数表示一个多边形。先把被表示的多边形分解成树形结构,然后使用R函数对满足多边形边的连续函数F(x,y)=0进行交、并等布尔操作,以获得表示整个多边形的隐函数。     

Representation theorem for probabilities on IFS-events

Rie?an gave in Rie?an (2004) [9] an axiomatic characterization of a probability on IFS-events and proved in Rie?an (2006) [10] a representation theorem for it. In Ren?ová [9], Ren?ová introduced the notions of additive φ-probability and strongly additive φ-probability and gave a representation theorem for strongly additive φ-probabilities.In this paper we give a generalization of the axiomatic characterization given by Rie?an in Rie?an (2006) [10]; from this, the representation theorem for strongly additive φ-probabilities will follow.