43125969
On claws belonging to every tournament
A directed graph is said to ben-unavoidable if it is contained as a subgraph by every tournament onn vertices. A number of theorems have been proven showing that certain graphs aren-unavoidable, the first being Rédei's results that every tournament has a Hamiltonian path. M. Saks and V. Sós gave more examples in [6] and also a conjecture that states: Every directed claw onn vertices such that the outdegree of the root is at most [n/2] isn-unavoidable. Here a claw is a rooted tree obtained by identifying the roots of a set of directed paths. We give a counterexample to this conjecture and prove the following result:any claw of rootdegree≤n/4 is n-unavoidable.
28342911
A matching game
Abstract We consider the following 2-person game playing on K n,n . Two players, maker and breaker, alternately take a previously untaken edge from K n,n , the complete bipartite graph of order 2 n . The game continues until all the edges of K n,n have been taken. Then the edges taken by maker induce a subgraph of K n,n , which is denoted by G ( M ). At the end of the game, we calculate the number of edge-disjoint perfect matchings of G ( M ), and denote this number by m ( M ). The maker's aim is to make this number big and the breaker's is to force it small. We will prove the following result: For any given η >0, there exists N ( η ), such that if n ⩾ N ( η ), then maker has a strategy to guarantee m(M)⩾( 1 2 −η)n .
6155777
Claws contained in all n-tournaments
Abstract We prove that any claw of order n with degree d≤ 3 8 n is n-unavoidable, which means that any tournament of order n contains it as a subdigraph. A simple corollary is that any tournament has a directed Hamiltonian path.
550060
Automatic categorization of figures in scientific documents
Figures are very important non-textual information contained in scientific documents. Current digital libraries do not provide users tools to retrieve documents based on the information available within the figures. We propose architecture for retrieving documents by integrating figures and other information. The initial step in enabling integrated document search is to categorize figures into a set of pre-defined types. We propose several categories of figures based on their functionalities in scholarly articles. We have developed a machine-learning-based approach for automatic categorization of figures. Both global features, such as texture, and part features, such as lines, are utilized in the architecture for discriminating among figure categories. The proposed approach has been evaluated on a testbed document set collected from the CiteSeer scientific literature digital library. Experimental evaluation has demonstrated that our algorithms can produce acceptable results for real- world use. Our tools can be integrated into a scientific-document digital library
1730176
Integrating Range and Texture Information for 3D Face Recognition
The performance of face recognition systems that use two-dimensional images depends on consistent conditions w.r.t. lighting, pose, and facial appearance. We are developing a face recognition system that utilizes three-dimensional shape information to make the system more robust to arbitrary view, lighting, and facial appearance. For each subject, a 3D face model is constructed by integrating several 2.5D face scans from different viewpoints. A 2.5D scan is composed of one range image along with a registered 2D color image. The recognition engine consists of two components, surface matching and appearance-based matching. The surface matching component is based on a modified Iterative Closest Point (ICP) algorithm.The candidate list used for appearance matching is dynamically generated based on the output of the surface matching component, which reduces the complexity of the appearance-based matching stage. The 3D model in the gallery is used to synthesize new appearance samples with pose and illumination variations that are used for discriminant subspace analysis. The weighted sum rule is applied to combine the two matching components. A hierarchical matching structure is designed to further improve the system performance in both accuracy and efficiency. Experimental results are given for matching a database of 100 3D face models with 598 2.5D independent test scans acquired in different pose and lighting conditions, and with some smiling expression. The results show the feasibility of the proposed matching scheme.
5605322
Multimodal Facial Gender and Ethnicity Identification
Human faces provide demographic information, such as gender and ethnicity. Different modalities of human faces, e.g., range and intensity, provide different cues for gender and ethnicity identifications. In this paper we exploit the range information of human faces for ethnicity identification using a support vector machine. An integration scheme is also proposed for ethnicity and gender identifications by combining the registered range and intensity images. The experiments are conducted on a database containing 1240 facial scans of 376 subjects. It is demonstrated that the range modality provides competitive discriminative power on ethnicity and gender identifications to the intensity modality. For both gender and ethnicity identifications, the proposed integration scheme outperforms each individual modality.
11665105
Agent-based autonomous information services integration and allocation to achieve high response and low cost in distributed information service system
The goal of autonomous information service integration is to enable information utilization opportunities far beyond those possible in a disconnected environment. We have proposed an agent-based distributed information service system architecture, called Faded Information Field (FIF) to cope with the rapidly evolving situations of providers' and users' heterogeneous requirements. In the case of a mono-service request, the system is designed to reduce the time needed for users to access the information and to preserve the consistency of the replicas. However, when the user requests joint selection of multiple services, synchronization of atomic actions and timeliness have to be assured by the system. The service-oriented autonomous integration and allocation for heterogeneous FIFs to provide one-stop service for users' multiservice requirements are proposed. Through the comparison simulation to conventional systems, the effectiveness of the proposed technology is proved.
5510684
Robust motion-based image segmentation using fusion
To support real-time tracking of objects in video sequences, there has been considerable effort directed at developing optical flow and general motion-based image segmentation algorithms. The goal is to segment multiple moving objects in the image based on their relative motion. This task can be complicated by the presence of lighting variations. Furthermore, a combination of multiple motions and complex lighting effects can lead to dramatic image variations that may not be adequately accounted for by a single motion-based segmentation algorithm. We propose to fuse the results of multiple motion segmentation algorithms to improve the system robustness. Our approach uses the expectation maximization (EM) algorithm as a fusion engine. It also uses principal components analysis (PCA) to perform dimensionality reduction to improve the performance of the EM algorithm and reduce the processing burden. The performance of the proposed fusion algorithm has been demonstrated in the "smart airbag" application of monitoring occupants in a moving automobile to determine if they are too close to the instrument panel (airbag). Through fusion of the outputs of multiple algorithms we are able to reduce the percentage of pixels missed on the target by 35.