Eindhoven University of Technology

About: Eindhoven University of Technology is a education organization based out in Eindhoven, Noord-Brabant, Netherlands. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 22309 authors who have published 52936 publications receiving 1584164 citations. The organization is also known as: Technische Hogeschool Eindhoven & TU/e.

Information retrieval in the World-Wide Web: making client-based searching feasible

Abstract: Finding specific information in the World-Wide Web (WWW, or Web for short) is becoming increasingly difficult, because of the rapid growth of the Web and because of the diversity of the information offered through the Web. Hypertext in general is ill-suited for information retrieval as it is designed for stepwise exploration. To help readers find specific information quickly, specific overview documents are often included into the hypertext. Hypertext systems often provide simple searching tools such as full text search or title search, that mostly ignore the “hyper-structure” formed by the links. In the WWW, finding information is further complicated by its distributed nature. Navigation, often via overview documents, still is the predominant method of finding one's way around the Web. Several searching tools have been developed, basically in two types: • A gateway, offering (limited) search operations on small or large parts of the WWW, using a pre-compiled database. The database is often built by an automated Web scanner (a “robot”). • A client-based search tool that does automated navigation, thereby working more or less like a browsing user, but much faster and following an optimized strategy. This paper highlights the properties and implementation of a client-based search tool called the “ fish-search ” algorithm, and compares it to other approaches. The fish-search, implemented on top of Mosaic for X, offers an open-ended selection of search criteria. Client-based searching has some definite drawbacks: slow speed and high network resource consumption. The paper shows how combining the fish search with a cache greatly reduces these problems. The “ Lagoon ” cache program is presented. Caches can call each other, currently only to further reduce network traffic. By moving the algorithm into the cache program, the calculation of the answer to a search request can be distributed among the caching servers.

The effects of multiview depth video compression on multiview rendering

Abstract: This article investigates the interaction between different techniques for depth compression and view synthesis rendering with multiview video plus scene depth data Two different approaches for depth coding are compared, namely H264/MVC, using temporal and inter-view reference images for efficient prediction, and the novel platelet-based coding algorithm, characterized by being adapted to the special characteristics of depth-images Since depth-images are a 2D representation of the 3D scene geometry, depth-image errors lead to geometry distortions Therefore, the influence of geometry distortions resulting from coding artifacts is evaluated for both coding approaches in two different ways First, the variation of 3D surface meshes is analyzed using the Hausdorff distance and second, the distortion is evaluated for 2D view synthesis rendering, where color and depth information are used together to render virtual intermediate camera views of the scene The results show that-although its rate-distortion (R-D) performance is worse-platelet-based depth coding outperforms H264, due to improved sharp edge preservation Therefore, depth coding needs to be evaluated with respect to geometry distortions

A Study Into the Factors That Influence the Understandability of Business Process Models

Abstract: Business process models are key artifacts in the development of information systems. While one of their main purposes is to facilitate communication among stakeholders, little is known about the factors that influence their comprehension by human agents. On the basis of a sound theoretical foundation, this paper presents a study into these factors. Specifically, the effects of both personal and model factors are investigated. Using a questionnaire, students from three different universities evaluated a set of realistic process models. Our findings are that both types of investigated factors affect model understanding, while personal factors seem to be the more important of the two. The results have been validated in a replication that involves professional modelers.

Diagnosing workflow processes using Woflan

Abstract: Workflow management technology promises a flexible solution for business-process support facilitating the easy creation of new business processes and modification of existing processes. Unfortunately, today’s workflow products have no support for workflow verification. Errors made at design-time are not detected and result in very costly failures at run-time. This paper presents the verification tool Woflan. Woflan analyzes workflow process definitions downloaded from commercial workflow products using state-of-the-art Petri-net-based analysis techniques. This paper describes the functionality of Woflan emphasizing diagnostics to locate the source of a design error. Woflan is evaluated via two case studies, one involving 20 groups of students designing a complex workflow process and one involving an industrial workflow process designed by Staffware Benelux. The results are encouraging and show that Woflan guides the user in finding and correcting errors in the design of workflows. Received 27 September 2000; revised 8 March 2001

From business process models to process-oriented software systems

Abstract: Several methods for enterprise systems analysis rely on flow-oriented representations of business operations, otherwise known as business process models. The Business Process Modeling Notation (BPMN) is a standard for capturing such models. BPMN models facilitate communication between domain experts and analysts and provide input to software development projects. Meanwhile, there is an emergence of methods for enterprise software development that rely on detailed process definitions that are executed by process engines. These process definitions refine their counterpart BPMN models by introducing data manipulation, application binding, and other implementation details. The de facto standard for defining executable processes is the Business Process Execution Language (BPEL). Accordingly, a standards-based method for developing process-oriented systems is to start with BPMN models and to translate these models into BPEL definitions for subsequent refinement. However, instrumenting this method is challenging because BPMN models and BPEL definitions are structurally very different. Existing techniques for translating BPMN to BPEL only work for limited classes of BPMN models. This article proposes a translation technique that does not impose structural restrictions on the source BPMN model. At the same time, the technique emphasizes the generation of readable (block-structured) BPEL code. An empirical evaluation conducted over a large collection of process models shows that the resulting BPEL definitions are largely block-structured. Beyond its direct relevance in the context of BPMN and BPEL, the technique presented in this article addresses issues that arise when translating from graph-oriented to block-structure flow definition languages.