Most wide-area caching schemes are client initiated. Decisions on when and where to cache information are made without the benefit of the server's global knowledge of the situation. We believe that the server should play a role in making these caching decisions, and we propose geographical push-caching as a way of bringing the server back into the loop. The World Wide Web is an excellent example of a widearea system that will benefit from geographical pushcaching, and we present an architecture that allows a Web server to autonomously replicate HTML pages. 1 Introduction The World-Wide Web [1] operates for the most part as a cache-less distributed system. When two neighboring clients retrieve a document from the same server, the document is sent twice. This is inefficient, especially considering the ease with which Web browsers allow users to transfer large multimedia documents. To combat this problem, some Web browsers have begun to add local client caches. These prevent one client...

This paper introduces a novel approach to distributed computing based on delegation-agents, and describes its applications to decentralize network management. Delegation agents are programs that can be dispatched to remote processes, dynamically linked and executed under local or remote control. Unlike scripted agents, delegation agent programs may be written in arbitrary languages, interpreted or compiled. They can thus be more broadly applied to handle such tasks as real-time monitoring, analysis and control of network resources. Distributed management by delegation (MbD) uses this to manage remote elements and domains. MbD provides a paradigm for distributed, exible, scalable and robust network management that overcomes the key limitations of current centralized management schemes. 1

Computer applications traditionally expect a static execution environment. However, this precondition is generally not possible for mobile systems, where the world around an application is constantly changing. This thesis explores how to support and also exploit the dynamic configurations and social settings characteristic of mobile systems. More specifically, it advances the following goals: (1) enabling seamless interaction across devices; (2) creating physical spaces that are responsive to users; and (3) and building applications that are aware of the context of their use. Examples of these goals are: continuing in your office a program started at home; using a PDA to control someone else's windowing UI; automatically canceling phone forwarding upon return to your office; having an airport overheaddisplay highlight the flight information viewers are likely to be interested in; easily locating and using the nearest printer or fax machine; and automatically turning off a PDA's audible e-mail notification when in a meeting.

The automated discovery of knowledge in databases is becoming increasingly important as the world's wealth of data continues to grow exponentially. Knowledge-discovery systems face challenging problems from real-world databases which tend to be dynamic, incomplete, redundant, noisy, sparse, and very large. This paper addresses these problems and describes some techniques for handling them. A model of an idealized knowledge-discovery system is presented as a reference for studying and designing new systems. This model is used in the comparison of three systems: CoverStory, EXPLORA, and the Knowledge Discovery Workbench. The deficiencies of existing systems relative to the model reveal several open problems for future research.

One of the most promising areas in Knowledge Discovery in Databases is the automatic analysis of changes and deviations. Several systems have recently been developed for this task. Success of these systems hinges on their ability to identify a few important and relevant deviations among the multitude of potentially interesting events. In this paper we argue that related deviations should be grouped together in a finding and that the interestingness of a finding is the estimated benefit from a possible action connected to it. We discuss methods for determining the estimated benefit from the impact of the deviations and the success probability of an action. Our analysis is done in the context of the Key Findings Reporter (KEFIR), a system for discovering and explaining "key findings" in large relational databases, currently being applied to the analysis of healthcare information. Keywords: knowledge discovery, databases, interestingness, deviations, healthcare 1 Introduction Many compan...

This paper describes Lua, a language for extending applications. Lua combines procedural features with powerful data description facilities, by using a simple, yet powerful, mechanism of tables. This mechanism implements the concepts of records, arrays, and recursive data types (pointers), and adds some object-oriented facilities, such as methods with dynamic dispatching. Lua presents a mechanism of fallbacks that allows programmers to extend the semantics of the language in some unconventional ways. As a noteworthy example, fallbacks allow the user to add different kinds of inheritance to the language. Currently, Lua is being extensively used in production for several tasks, including user configuration, general-purpose data-entry, description of user interfaces, storage of structured graphical metafiles, and generic attribute configuration for finite element meshes.

This paper describes the design and implementation of Paradise, a database system designed for handling GIS type of applications. The current version of Paradise, uses a client{server architecture and provides an extended{relational data model for modeling GIS applications. Paradise supports an extended version of SQL and provides a graphical user interface for querying and browsing the database. We also describe the results of benchmarking Paradise using the Sequoia 2000 storage benchmark. 1

In this paper, a method of encapsulating camera tasks into well defined units called “camera modules ” is described. Through this encapsulation, camera modules can be programmed and sequenced, and thus can be used as the underlying framework for controlling the virtual camera in widely disparate types of graphi-cal environments. Two examples of the camera framework are shown: an agent which can film a conversation between two virtual actors and a visual programming language for filming a virtual football game.

Ptolemy is an environment for simulation, prototyping, and software synthesis for heterogeneous systems. It uses modern object-oriented software technology (in C++) to model each subsystem in a natural and efficient manner, and to integrate these subsystems into a whole. The objectives of Ptolemy encompass practically all aspects of designing signal processing and communications systems, ranging from algorithms and communication strategies, through simulation, hardware and software design, parallel computing, and generation of real-time prototypes. In this paper we will introduce the software synthesis aspects of the Ptolemy system. The environment presented here is both modular and extensible. Ptolemy allows the user to choose among various single- or multiple-processor schedulers. 1.0 Introduction Practical signal processing systems today are rarely implemented without software or firmware, even at the ASIC level. Programmable DSPs, in particular, form the heart of many implementati...

This report addresses the problem of automatically synchronizing computer generated faces with synthetic speech. The complete process is called DECface which provides a novel form of face-to-face communicationand the ability to create a new range of talking personable synthetic characters. Based on plain ASCII text input, a synthetic speech segment is generated and synchronized in real-time to a graphical display of an articulating mouth and face. The key component of DECface is the run-time facility that adaptively synchronizes the graphical display of the face to the audio. Keywords: face-to-face, key-framing, anatomically-based, text-to-speech, viseme, phonetics c flDigital Equipment Corporation 1993. All rights reserved. UNIX is a trademark of Unix Systems Laboratories. Apple is a registered tradmark of Apple Computer, Inc. The following are trademarks of Digital Equipment Corporation: Alpha AXP, DEC, DECaudio, DECstation, DECtalk, TURBOchannel, ULTRIX, XMedia, and the DIGITAL log...