52809806
Deformable Shape Detection and Description via Model-Based Region Grouping
Certain thermoplastic blends have substantially improved hot strength (i.e., cohesive strength and resistance to sagging or tearing during milling or other hot processing). The blends comprise (1) at least one ethylene-propylene (EP) or ethylene-propylene-diene (EPDM) polymer and (2) at least one highly crystalline polyallomer, and are useful for tubing, wire and cable insulation, molded items and the like.
12537942
Deformable shape detection and description via model-based region grouping
A method for deformable shape detection and recognition is described. Deformable shape templates are used to partition the image into a globally consistent interpretation, determined in part by the minimum description length principle. Statistical shape models enforce the prior probabilities on global, parametric deformations for each object class. Once trained, the system autonomously segments deformed shapes from the background, while not merging them with adjacent objects or shadows. The formulation can be used to group image regions based on any image homogeneity predicate; e.g., texture, color or motion. The recovered shape models can be used directly in object recognition. Experiments with color imagery are reported.
32876579
Medical image segmentation and retrieval via deformable models
A new method based on deformable shape models for medical image segmentation is described. Experiments for blood cell micrographs have been conducted to verify the accuracy of the shape model-based segmentation and object shape description method. The cell segmentation method does not require user input for initialization. Coherence information between cells is utilized via a globally consistent cost function. The proposed segmentation method can be used in automated analysis for images of stained blood smear and segmentation of other medical structures. A method for shape population-based retrieval is also described. Results of population-based image queries for a database of blood cell micrographs are shown.
27027454
Shape-Guided Split and Merge of Image Regions
A method for deformable shape-based image segmentation is described. Regions in an image are merged together and/or split apart, based on their agreement with an a priori distribution on the global deformation parameters for a shape template. Perceptually-motivated criteria are used to determine where and how to split regions, based on the local shape properties of the region group's bounding contour. In general, finding the globally optimal region partition for an image is an NP hard problem; therefore, two approximation strategies are employed: the highest confidence first algorithm and shape indexing trees. Experiments show that the speedup obtained through use of the approximation strategies is significant, while accuracy of segmentation remains high. Once trained, the system autonomously segments shapes from the background, while not merging them with adjacent objects or shadows.
45704904
Automatic Deformable Shape Segmentation for Image Database Search Applications
A method for shape based image database indexing is described. Deformable shape templates are used to group color image regions into globally consistent configurations. A statistical shape model is used to enforce the prior probabilities on global, parametric deformations for each object class. The segmentation is determined in part by the minimum description length (MDL) principle. Once trained, the system autonomously segments deformed shapes from the background, while not merging them with adjacent objects or shadows. The formulation can be used to group image regions based on any image homogeneity predicate; e.g., texture, color, or motion. Preliminary experiments in color segmentation and shape-based retrieval are reported.
18654729
Reliable peer-to-peer end system multicasting through replication
A key challenge in peer-to-peer computing system is to provide decentralized and yet reliable services on top of a network of loosely coupled, weakly connected and possibly unreliable peers. This work presents an effective dynamic passive replication scheme designed to provide reliable multicast service in peer-cast, an efficient and self-configurable peer-to-peer end system multicast (ESM) system. We first describe the design of a distributed replication scheme, which enables reliable subscription and multicast dissemination of information in an environment of inherently unreliable peers. Then we present an analytical model to discuss its fault tolerance properties, and report a set of initial experiments, showing the feasibility and the effectiveness of the proposed approach.
47117005
A reputation-based trust model for peer-to-peer e-commerce communities
Peer-to-peer e-commerce (electronic commerce) communities are commonly perceived as an environment offering both opportunities and threats. One way to minimize threats in such an open community is to use community-based reputations to help evaluating the trustworthiness and predicting the future behavior of peers. We present PeerTrust - a coherent adaptive trust model for quantifying and comparing the trustworthiness of peers based on a transaction-based feedback system. There are two main features of our model. First, we introduce three basic trust parameters in computing trustworthiness of peers. In addition to feedback a peer receives through its transactions with other peers, we incorporate the total number of transactions a peer performs, and the credibility of the feedback sources into the model for evaluating the trustworthiness of peers. We argue that the trust models based solely on feedback from other peers in the community are inaccurate and ineffective. Second, we introduce two adaptive trust factors, the transaction context factor and the community context factor, to allow the basic trust metric to incorporate different contexts (situations) and to address common problems encountered in a variety of online e-commerce communities. We present a concrete method to validate the proposed trust model and report the set of simulation-based experiments, showing the feasibility and benefit of the PeerTrust model.
1558238
Spam-Resilient Web Rankings via Influence Throttling
Web search is one of the most critical applications for managing the massive amount of distributed Web content. Due to the overwhelming reliance on Web search, there is a rise in efforts to manipulate (or spam) Web search engines. In this paper, we develop a spam-resilient ranking model that promotes a source-based view of the Web. One of the most salient features of our spam-resilient ranking algorithm is the concept of influence throttling. We show how to utilize influence throttling to counter Web spam that aims at manipulating link-based ranking systems, especially PageRank-like systems. Through formal analysis and experimental evaluation, we show the effectiveness and robustness of our spam-resilient ranking model in comparison with existing Web algorithms such as PageRank.
9444422
A Systematic Approach to Flexible Specification, Composition, and Restructuring of Workflow Activities
We introduce the ActivityFlow specification language for flexible specification, composition, and coordination of workflow activities. The most interesting features of the ActivityFlow specification language include: (1) a collection of specification mechanisms, allowing workflow designers to use a uniform workflow specification interface to describe different types (i.e., ad-hoc, administrative, or production) of workflows involved in their organizational processesâ€“ this feature helps to increase the flexibility of workflow processes in accommodating various types of changes; (2) a set of activity modeling facilities, enabling workflow designers to describe the flow of work declaratively and incrementally, allowing to reason about correctness and security of complex workflow activities independently from their underlying implementation mechanisms; (3) an open architecture that supports user interaction as well as collaboration of workflow systems of different organizations, and a set of workflow activity restructuring operators to respond to dynamic changes of workflow activities. We end the paper with a series of simulation-based experiments that demonstrate the effectiveness of these restructuring operators and the implementation architecture of the ActivityFlow system.
5150850
Formalizing UML Models with Object-Z
The Unified Modeling Language (UML) has been developed as a standard language for object-oriented designs. Through its graphical and intuitive diagrams, software analysis and design process become easy. However, this graphical notation lacks precisely defined semantics. It is difficult to determine whether the design is consistent, unambiguous and complete. This paper provides a method of formalizing UML models. It gives the transforming rules from UML models to Object-Z constructs. With this method, the semantics of UML models are directly expressed in formal language Object-Z. The UML class, sequence and statechart diagrams are formalized using this method. A tool OZRose is developed to automate the transforming process.