33192319
Hierarchical model based human motion tracking
Image sequence based tracking is the pivotal technique of human motion. In the paper, we first propose an appropriate human model and color model. Second, two approaches are proposed aiming at two different levels of color-block information including the boundary and the inner-area: the extraction of the boundary algorithm is based on the Robert operator and the clustering algorithm is based on self-adaptation. Third, we unite two regions, which are processed by different approaches. This step counteracts the ambiguity of obtaining information from each level. Finally, after the rough area of the color-block is obtained, the boundary of the color-block is determined by calculating the histogram of the X,Y coordinate of every point on the boundary of the block. Experimental results are presented.
5411538
A unified adaptive approach to accurate skin detection
Due to variations of lighting conditions and camera hardware settings and the existence of many ethnic people with a wide range of skin colors, a generic skin model is often inadequate to accurately capture the skin distribution for individual images. In this paper, we propose an adaptive skin detection framework, which allows modeling title skin distribution with significantly higher accuracy and flexibility. First, an adaptive skin model, specific to the image under consideration and refined from the skin-similar space, is derived using a Gaussian mixture model (GMM) and standard expectation maximization (EM) algorithm. Then, we develop a support vector machine (SVM) classifier to identify the skin Gaussian from the trained GMM (with two Gaussian components) by incorporating spatial and shape information of skin pixels. Extensive experimental results performed on large image databases have demonstrated the effectiveness and benefits of the proposed approach.
1096901
Developing Evolutionary Cost Models for Query Optimization in a Dynamic Multidatabase Environment
Deriving local cost models for query optimization in a multidatabase system (MDBS) is a challenging issue due to local autonomy. It becomes even more difficult when dynamic environmental factors are taken into consideration. In this paper, we study how to evolve a cost model to capture a slowly-changing dynamic MDBS environment so that the cost model is kept up-to-date all the time. We propose a novel evolutionary technique, called the shifting method, to tackle this issue. The key idea is to adjust a cost model by adding the up-to-date performance information of a new sample query into and, in the meantime, removing the out-of-date information of the oldest sample query from consideration at each step. It is shown that this method is more efficient than the direct re-building approach. The relevant issues including derivation of recurrence update formulas, development of efficient algorithm, analysis of complexities as well as some aspects of implementation are studied. Our theoretical and experimental results demonstrate that the proposed shifting method is quite promising in deriving accurate evolutionary cost models for a slowly-changing dynamic MDBS environment.
8171494
The ND-Tree: A Dynamic Indexing Technique for Multidimensional Non-ordered Discrete Data Spaces
Similarity searches in multidimensional Nonordered Discrete Data Spaces (NDDS) are becoming increasingly important for application areas such as genome sequence databases. Existing indexing methods developed for multidimensional (ordered) Continuous Data Spaces (CDS) such as R-tree cannot be directly applied to an NDDS. This is because some essential geometric concepts/properties such as the minimum bounding region and the area of a region in a CDS are no longer valid in an NDDS. On the other hand, indexing methods based on metric spaces such as M-tree are too general to effectively utilize the data distribution characteristics in an NDDS. Therefore, their retrieval performance is not optimized. To support efficient similarity searches in an NDDS, we propose a new dynamic indexing technique, called the ND-tree. The key idea is to extend the relevant geometric concepts as well as some indexing strategies used in CDSs to NDDSs. Efficient algorithms for ND-tree construction are presented. Our experimental results on synthetic and genomic sequence data demonstrate that the performance of the ND-tree is significantly better than that of the linear scan and M-tree in high dimensional NDDSs.
11459525
Classifying Local Queries for Global Query Optimization in Multidatabase Systems
A multidatabase system (MDBS) integrates information from multiple pre-existing local databases. A major challenge for global query optimization in an MDBS is that some required local information a...
9544892
OBJ-NET: An Object Oriented System Design Tool
Computer-based Systems are used in a wide range of complex systems like automobile assembly lines, power plants, etc. These systems consist of heterogeneous subsystems having a multitude of interactions with other subsystems and environments. Designing software for such systems is a difficult task due to the inherent complexity both at conceptual and implementation levels. When developing a large system, the constituent subsystems may be developed separately. Those subsystems may work well on their own, but may fail to work together with other subsystems and fail to respond to interfacing events. This paper presents OBJ-NET, an object oriented system design tool, which provides a suitable framework for the specification and simulation of complex dynamic systems. The theoretical basis of OBJ-NET is from Category Theory and Petri Nets. OBJ-NET helps users to integrate complex systems by modeling a system as a hierarchy of components. It accepts the flow of control from one set of objects to another and simulates the flow of control among the various components of the system. This will allow a user to validate the correctedness of design and interactively change the design to refine the working of the system. This paper describes the various components of OBJ-NET in detail and illustrates the application of OBJ-NET using, as a working example, the specification and simulation of an Automotive Dashboard System.
2718324
Supporting database access in the Hermes programming language
The work reported in this paper is part of a project aimed at designing and prototyping an application development environment that allows easy development of platform-independent distributed applications. The main goals of the database subproject are to investigate methods for (1) providing (SQL) database access and (2) supporting transaction management within a distributed programming environment based on the paradigm of communicating sequential processes. This paper looks at how SQL database access can be provided in Hermes, a new language for distributed programming based on this paradigm. The paper compares the characteristics of Hermes and SQL tables, discusses potential ways of supporting database access in Hermes, and then defines an embedding of SQL in Hermes. Some implementation aspects are also discussed.