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Mark J. Stefik

Bio: Mark J. Stefik is an academic researcher from PARC. The author has contributed to research in topics: Parking guidance and information & Topic model. The author has an hindex of 49, co-authored 220 publications receiving 16487 citations. Previous affiliations of Mark J. Stefik include Stanford University & Xerox.


Papers
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Patent
23 Nov 1995
TL;DR: In this article, a system for controlling use and distribution of digital works, in which the owner of a digital work attaches usage rights to that work, is presented, where each right has associated with it certain optional specifications which outline the conditions and fees upon which the right may be exercised.
Abstract: A system for controlling use and distribution of digital works, in which the owner of a digital work (101) attaches usage rights (102) to that work. Usage rights are granted by the "owner" of a digital work to "buyers" of the digital work. The usage rights define how a digital work may be used and further distributed by the buyer. Each right has associated with it certain optional specifications which outline the conditions and fees upon which the right may be exercised. Digital works are stored in a repository. A repository will process each request (103,104) to access a digital work by examining the corresponding usage rights (105). Digital work playback devices, coupled to the repository containing the work, are used to play, display or print the work. Access to digital works for the purposes of transporting between repositories (e.g. copying, borrowing or transfer) is carried out using a digital work transport protocol. Access to digital works for the purposes of replay by a digital work playback device(e.g. printing, displaying or executing) is carried out using a digital work playback protocol. Access is denied (106) or granted (107) depending whether the requesting repository has the required usage rights.

1,279 citations

Patent
Mark J. Stefik1
23 Nov 1994
TL;DR: In this article, a system for controlling use and distribution of digital works is presented, which allows the owner of a digital work to attach usage rights to their work, which define how the individual digital work may be used and distributed.
Abstract: A system for controlling use and distribution of digital works. The present invention allows the owner of a digital work to attach usage rights to their work. The usage rights define how the individual digital work may be used and distributed. Instances of usage rights are defined using a flexible and extensible usage rights grammar. Conceptually, a right in the usage rights grammar is a label associated with a predetermined behavior and conditions to exercising the right. The behavior of a usage right is embodied in a predetermined set of usage transactions steps. The usage transaction steps further check all conditions which must be satisfied before the right may be exercised. These usage transaction steps define a protocol for requesting the exercise of a right and the carrying out of a right.

1,079 citations

Journal ArticleDOI
TL;DR: The Colab meeting room at Xerox PARC as mentioned in this paper has been created to study computer support of collaborative problem solving in face-to-face meetings, and the long-term goal is to understand how to build computer tools to make meetings more effective.
Abstract: Although individual use of computers is fairly widespread, in meetings we tend to leave them behind. At Xerox PARC, an experimental meeting room called the Colab has been created to study computer support of collaborative problem solving in face-to-face meetings. The long-term goal is to understand how to build computer tools to make meetings more effective.

959 citations

Patent
23 Nov 1995
TL;DR: In this paper, a system for controlling the distribution and use of digital works using digital tickets is presented, where a digital ticket is used to entitle the ticket holder to exercise some usage right with respect to a digital work.
Abstract: A system for controlling the distribution and use of digital works using digital tickets. In the present invention, a “digital ticket” is used to entitle the ticket holder to exercise some usage right with respect to a digital work. Usage rights are used to define how a digital work may be used or distributed. Each usage right may specify a digital ticket which must be present before the right may be exercised. Digital works are stored in repositories which enforce a digital works usage rights. Each repository has a “generic ticket agent” which punches tickets. In some instances only the generic ticket agent is necessary. In other instances, punching by a “special ticket agent” residing on another repository may be needed.

922 citations

Journal ArticleDOI
TL;DR: This paper presents an approach to hierarchical planning, termed constraint posting, that uses constraints to represent the interactions between subproblems and is illustrated with a computer program that plans gene-cloning experiments in molecular genetics.

858 citations


Cited by
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Patent
30 Sep 2010
TL;DR: In this article, the authors proposed a secure content distribution method for a configurable general-purpose electronic commercial transaction/distribution control system, which includes a process for encapsulating digital information in one or more digital containers, a process of encrypting at least a portion of digital information, a protocol for associating at least partially secure control information for managing interactions with encrypted digital information and/or digital container, and a process that delivering one or multiple digital containers to a digital information user.
Abstract: PROBLEM TO BE SOLVED: To solve the problem, wherein it is impossible for an electronic content information provider to provide commercially secure and effective method, for a configurable general-purpose electronic commercial transaction/distribution control system. SOLUTION: In this system, having at least one protected processing environment for safely controlling at least one portion of decoding of digital information, a secure content distribution method comprises a process for encapsulating digital information in one or more digital containers; a process for encrypting at least a portion of digital information; a process for associating at least partially secure control information for managing interactions with encrypted digital information and/or digital container; a process for delivering one or more digital containers to a digital information user; and a process for using a protected processing environment, for safely controlling at least a portion of the decoding of the digital information. COPYRIGHT: (C)2006,JPO&NCIPI

7,643 citations

Journal ArticleDOI
TL;DR: This survey characterizes an emerging research area, sometimes called coordination theory, that focuses on the interdisciplinary study of coordination, that uses and extends ideas about coordination from disciplines such as computer science, organization theory, operations research, economics, linguistics, and psychology.
Abstract: This survey characterizes an emerging research area, sometimes called coordination theory, that focuses on the interdisciplinary study of coordination. Research in this area uses and extends ideas about coordination from disciplines such as computer science, organization theory, operations research, economics, linguistics, and psychology.A key insight of the framework presented here is that coordination can be seen as the process of managing dependencies among activities. Further progress, therefore, should be possible by characterizing different kinds of dependencies and identifying the coordination processes that can be used to manage them. A variety of processes are analyzed from this perspective, and commonalities across disciplines are identified. Processes analyzed include those for managing shared resources, producer/consumer relationships, simultaneity constraints, and task/subtask dependencies.Section 3 summarizes ways of applying a coordination perspective in three different domains:(1) understanding the effects of information technology on human organizations and markets, (2) designing cooperative work tools, and (3) designing distributed and parallel computer systems. In the final section, elements of a research agenda in this new area are briefly outlined.

3,447 citations

Journal ArticleDOI
TL;DR: C categories and examples of groupware are described and some underlying research and development issues are discussed and GROVE, a novel group editor, is explained in some detail as a salient groupware example.
Abstract: Groupware reflects a change in emphasis from using the computer to solve problems to using the computer to facilitate human interaction. This article describes categories and examples of groupware and discusses some underlying research and development issues. GROVE, a novel group editor, is explained in some detail as a salient groupware example

2,891 citations

Book ChapterDOI
18 Jun 2001
TL;DR: AspectJ provides support for modular implementation of a range of crosscutting concerns, and simple extensions to existing Java development environments make it possible to browse the crosscutting structure of aspects in the same kind of way as one browses the inheritance structure of classes.
Abstract: AspectJ? is a simple and practical aspect-oriented extension to Java?. With just a few new constructs, AspectJ provides support for modular implementation of a range of crosscutting concerns. In AspectJ's dynamic join point model, join points are well-defined points in the execution of the program; pointcuts are collections of join points; advice are special method-like constructs that can be attached to pointcuts; and aspects are modular units of crosscutting implementation, comprising pointcuts, advice, and ordinary Java member declarations. AspectJ code is compiled into standard Java bytecode. Simple extensions to existing Java development environments make it possible to browse the crosscutting structure of aspects in the same kind of way as one browses the inheritance structure of classes. Several examples show that AspectJ is powerful, and that programs written using it are easy to understand.

2,810 citations

Journal ArticleDOI
Mark D. Weiser1
TL;DR: What is new and different about the computer science in ubiquitous computing is explained, and a series of examples drawn from various subdisciplines of computer science are outlined.
Abstract: Ubiquitous computing is the method of enhancing computer use by making many computers available throughout the physical environment, but making them effectively invisible to the user. Since we started this work at Xerox PARC in 1988, a number of researchers around the world have begun to work in the ubiquitous computing framework. This paper explains what is new and different about the computer science in ubiquitous computing. It starts with a brief overview of ubiquitous computing, and then elaborates through a series of examples drawn from various subdisciplines of computer science: hardware components (e.g. chips), network protocols, interaction substrates (e.g. software for screens and pens), applications, privacy, and computational methods. Ubiquitous computing offers a framework for new and exciting research across the spectrum of computer science.

2,662 citations