Contents in Current Page:

1. alpha Trellis - Introduction
2. alpha Trellis - Browsing ( Paper )
3. alpha Trellis - programmable browsing semantics ( Paper )
4. alpha trellis - formal definition ( paper )
5. alpha Trellis - access control (Paper)
6. alpha Trellis - Temporal Hyperprogramming (Paper)
7. alpha Trellis - Parallel Browsing ( Paper )
8. alpha Trellis - Hypertext meta-structure (Paper)

alpha Trellis - Introduction

aTrellis is a prototype hypertext implementation based in Trellis model. Trellis model is based in Petri nets, a generalisation of traditional directed graph models. Trellis is a well documented model which permits development of browsing and  authoring systems that can incorporate formal techniques have been developed for Petri nets and to incorporate user interface designs for hypertext systems. Trellis supports concurrent navigation using multiple paths and synchronisation between them. Nodes in Trellis are represented by places in Petri net and links by transitions. Trellis support adaptive link display since each button do not appear until they ready to fire. Tailored versions of hypertext can be supported.

 alpha Trellis - Browsing ( Paper )

Doc Type: Conference Paper Title: alpha Trellis: a system for writing and browsing   Petri-net-based hypertext Authors: Stotts, P.D.; Furuta, R. Affiliation: Dept. of Comput. Sci., Maryland Univ., College Park, MD,  USA Conf. Title: Advances in  Petri Nets 1990 p. 471-90 Editors: Rozenberg, G. Publisher: Springer-Verlag  Berlin, Germany  Date: 1991 vi+515 pp.  Country of Publication: Germany  ISBN: 3 540 53863 1 Language: English  Conf. Date: 28-30 June 1989  Conf. Loc: Bonn, West Germany Treatment: Theoretical/Mathematical Abstract: The  traditional hypertext model resembles a directed graph. The authors' model, based on Petri nets, also represents the hypertext's browsing semantics (i.e. how the  information is to be visited). The Petri net model is a generalization of traditional directed graph models. It permits development of browsing and authoring systems  that can incorporate the analytical techniques that have been developed for Petri nets and also incorporate the user interface designs that have been developed for  hypertext systems. The Petri net base also permits powerful specification of how the hypertext is to be browsed. New abilities include synchronization of simultaneous traversals of separate paths through a hypertext as well as of  security/access control considerations into a hypertext (specifying nodes that can be proven accessible only to certain classes of browsers). In addition, different tailored versions can be generated from a single document structure in the Petri net-based model. This report describes the Petri net-based Trellis model, a prototype hypertext implementation called alpha Trellis, and an early version of an authoring language for Petri net-based documents called Alpha alpha . (25 Refs.) Classification: C6115 (Programming support); C6180 (User interfaces); C1160 (Combinatorial mathematics) Thesaurus: Hypermedia; Petri nets; Software tools; User interfaces Free Terms: Information fragments; Browsing; Petri-net-based  hypertext; Directed graph; User interface designs; Hypertext systems;  Synchronization; Simultaneous traversals; Access control; Document  structure; Petri net-based Trellis model; Prototype hypertext; Alpha  Trellis; Authoring language; Petri net-based documents; Alpha alpha

 alpha Trellis - programmable browsing semantics ( Paper )

Doc Type: Conference Paper in Journal Title: Programmable browsing semantics in Trellis Authors: Furuta, R.; Stotts, P.D. Affiliation: Dept. of Comput. Sci.,  Maryland Univ., College Park, MD,  USA Journal: SIGCHI Bulletin  Iss: spec. issue. p. 27-42  Date: Nov. 1989  Country of Publication: USA  ISSN:  0736-6906 CODEN: SGBUD4 Language: English Conf. Title:Hypertext '89 Proceedings  Conf. Date: 5-8 Nov. 1989  Conf. Loc: Pittsburgh, PA, USA  Conf.  Sponsor: ACM Treatment: Practical Abstract:Different researchers have different ideas about how a hypertext should be navigated. Each new implementation of a  hypertext browser works slightly differently from previous ones. This is due both to variations in personal taste and to discoveries of new, useful ways to organize and  present information. The authors outline a technique by which a hypertext system can offer flexible, programmable browsing behavior, or browsing semantics. Differences in the way documents are to be browsed can be specified by an author on a document-by-document basis, or by a style designer for an entire class of  documents. The ability to specify and modify how a browser presents information is an important and useful property in general. The authors first discuss the issues involved in programmable browsing semantics, and then they present one method of providing them within the context of the Trellis project at the University of Maryland. (11 Refs.) Classification: C7250 (Information storage and retrieval); C6160Z (Other DBMS) Thesaurus: Hypermedia Free Terms: Programmable browsing semantics; Trellis; Hypertext

alpha trellis - formal definition ( paper )

Title: Petri-net-based hypertext: document structure with  browsing semantics  Authors: Stotts, P.D.; Furuta, R. Affiliation: Maryland Univ., College Park, MD, USA Journal: ACM Transactions on Information Systems  Vol: 7 Iss: 1 p. 3-29  Date: Jan. 1989  Country of Publication: USA  ISSN: 0734-2047  CCC: 0734-2047/89/0100-0003$01.50 Language: English Treatment: Practical; Theoretical/Mathematical Abstract: Presents a formal definition of the Trellis model of hypertext and describe an authoring and browsing prototype called alpha Trellis  that is based on the model. The Trellis model not only represents the relationships that tie individual pieces of information together into a document (i.e., the adjacencies), but specifies the browsing semantics to be associated with the hypertext as well (i.e., the manner in which the information is to be visited and presented). The model is based on Petri nets, and is a generalization of existing directed graph-based forms of hypertext. The Petri net basis permits more  powerful specification of what is to be displayed when a hypertext is browsed and permits application of previously developed Petri net analysis techniques to verify  properties of the hypertext. A number useful hypertext constructs, easily described in the Trellis model, are presented. These include the synchronization of simultaneous traversals of separate paths through a hypertext, the incorporation of access controls into a hypertext (i.e., specifying nodes that can be proven to be accessible only to certain classes of browsers), and construction of multiple specialized (tailored) versions from a single hypertext. (34 Refs.) Classification: C4250 (Database theory); C6130D (Document processing techniques); C1160 (Combinatorial mathematics); C7250 (Information storage and retrieval); C6160Z (Other DBMS) Thesaurus: Database theory; Hypermedia; Information retrieval; Petri nets; Synchronisation Free Terms: Node specification, multiple specialized versions; Petri-net-based hypertext; Document structure; Browsing semantics;  Formal definition; Trellis model; Authoring; Alpha Trellis; Adjacencies; Directed graph-based forms; Synchronization; Simultaneous traversals; Access controls

 alpha Trellis - access control (Paper)

Title: Access control and verification in Petri-net-based  hyperdocuments Authors: Stotts, P.D.; Furuta, R. Affiliation: Dept. of Comput. Sci., Maryland Univ., College Park, MD,  USA Conf. Title: COMPASS '89 Proceedings of the Fourth Annual Conference on Computer Assurance. Systems Integrity, Software Safety and Process Security (Cat. No.89CH2656-7) p. 49-55  Publisher: IEEE  New York, NY, USA  Date: 1989 125 pp.  Country of Publication: USA  Language: English  Conf. Date: 19-23 June 1989  Conf. Loc: Gaithersburg, MD, USA  Conf.  Sponsor: IEEE; Comput. Sci. Corp.; Georgetown  Univ.; NIST; et al Treatment: Practical Abstract: The Petri-net-based trellis model of hypertext is briefly  described, and the access control capabilities that the model provides for hyperdocuments is discussed. The trellis model captures not only the logical relationships among information elements, but also the dynamic properties of a  reader's experience when browsing a document. Using the Petri-net formalism, a hypertext document can be written so that different classes of readers can be allowed or denied access to various portions of the document. The use of browsing restrictions and multiple document versions to implement access classes is  discussed. While many of the access capabilities described are not different from those available with graph augmentation techniques, it is believed that the Petri net  notation is as intuitively easy to use while being more succinct and convenient. (23 Refs.) Classification: C6160Z (Other DBMS); C1160 (Combinatorial mathematics); C7250 (Information storage and retrieval) Thesaurus: Hypermedia; Petri nets; Program verification Free Terms: Verification; Petri-net-based hyperdocuments; Petri-net-based trellis model; Hypertext; Access control; Logical  relationships; Information elements; Dynamic properties; Browsing; Multiple document versions; Access classes; Graph augmentation techniques

alpha Trellis - Temporal Hyperprogramming (Paper)

INSPEC 3796496 C91011256 Doc Type: Journal Paper Title: Temporal hyperprogramming Authors: Stotts, P.D.; Furuta, R. Affiliation: Dept. of Comput. Sci., Maryland Univ., College Park, MD,  USA Journal: Journal of Visual Languages and Computing  Vol: 1 Iss: 3 p. 237-53  Date: Sept. 1990  Country of Publication: UK  ISSN: 1045-926X  CCC: 1045-926X/90/030237+17$03.00/0 Language: English Treatment: Practical Abstract: The visual programming aspects  of Trellis hypertext documents are described. A hypertext is a nonlinearly organized, browsable information structure. The importance of browsing distinguishes hypertext from other network information systems. The possible  experiences a user may have when interacting with a hypertext are as important as its form. Further, these browsing semantics should be an inherent characteristic of a  document, not of the implementation that allows browsing. In essence, a hypertext is an active entity that has a visible behavior, not a static entity that is manipulated  by external means. The Trellis model employs the dual nature of Petri nets to formally express both aspects of a hypertext in one structure. A Petri net is a bipartite graph, so it captures the link structure of relationships among information elements. It is also an automaton, having an execution state and state transition  rules, thereby formally capturing the interactions between reader and document. The authors define the temporal semantics of the Trellis model and illustrate them with a prototype hypertext system called alpha Trellis. This environment joins timed events and active computing engines into a dynamic, parallel browsing structure. In alpha Trellis, hypertext authoring is visual programming for a temporally-synchronized, visual outcome-temporal hyperprogramming. (11 Refs.) Classification: C6160Z (Other DBMS); C6130B (Graphics techniques); C6180 (User interfaces) Thesaurus: Computer graphics; Formal logic; Hypermedia; Petri  nets; Programming; User interfaces Free Terms: Visual programming; Trellis hypertext documents; Browsable information structure; Network information systems; Petri nets; Bipartite graph; Temporal semantics; Alpha Trellis; Timed  events; Active computing engines; Parallel browsing structure; Hypertext authoring; Temporal hyperprogramming

 alpha Trellis - Parallel Browsing ( Paper )

Doc Type: Journal Paper Title: Browsing parallel process networks Authors: Stotts, P.D.; Furuta, R. Affiliation: Dept. of Comput. Sci., Maryland Univ., College Park, MD, USA Journal: Journal of Parallel and Distributed Computing  Vol: 9 Iss: 2 p. 224-35  Date: June 1990  Country of Publication: USA  ISSN: 0743-7315  CODEN: JPDCER  CCC: 0743-7315/90/$3.00 Language: English Treatment: Theoretical/Mathematical Abstract: A hypertext is a non-linearly organized, linked information structure, designed to be interactively browsed. The authors  demonstrate the use of a hypertext system for visualization and simulation of the parallel control flow and message network of concurrent programs. Instead of constructing code browsers as special-purpose window systems that understand the syntax and semantics of particular languages. They present a general approach  that relies on the (usually extensive) browsing facilities of a hypertext system. Language-specific browsers can be realized by generating filters to convert program text into hypertext documents. They demonstrate the filter approach specifically with the parallel language CSP and the alpha Trellis hypertext system.  alpha Trellis employs the dual nature of Petri nets to express formally in one structure both the linked information elements of a document and the reader/document interactions during browsing. alpha Trellis is especially appropriate for parallel program browsing because Petri nets are a natural concurrency model, and because it offers state-space analysis for deadlocks and  other program properties. alpha Trellis-based program browsers for other parallel languages can be produced by designing appropriate Petri net translations. (15 Refs.) Classification: C6110 (Systems analysis and programming) Thesaurus: Hypermedia; Parallel programming (Free Terms: Parallel process networks; Hypertext; Message network; Concurrent programs; Code browsers; Filter  approach; Parallel language; CSP; Petri nets; Concurrency model

alpha Trellis - Hypertext meta-structure (Paper)

 Doc Type: Journal Paper Title: A functional meta-structure for hypertext models and systems Authors: Furuta, R.; Stotts, P.D. Affiliation: Dept. of Comput. Sci.,  Maryland Univ., College Park, MD,  USA Journal: Electronic Publishing: Origination, Dissemination and  Design  Vol: 3 Iss: 4 p. 179-205  Date: Nov. 1990   Country of Publication: UK  ISSN: 0894-3982 CODEN: EPODEU  CCC: 0894-3982/90/040179-27$13.50 Language: English Treatment: Practical Abstract: A hypertext 'meta-structure' is one that provides an organization for the architecture of hypertext models and systems. The meta-structure was initially developed to help understand the architecture of a specific hypertext model (the  Trellis hypertext model). However, its organization seems generally applicable to a wide range of other models and systems as well. As such, the meta-structure is a  good candidate for a high-level hypertext reference model, and so we refer to it as the Trellis hypertext reference model, or the r-model. The r-model represents a hypertext at five levels of abstraction-two abstract levels, two concrete levels, and one visible level. The authors present the r-model, use it to classify four different  hypertext (and hypertext-like) systems, and then discuss its relationship to various hypertext-defined concepts. (36 Refs.) Classification: C6160Z (Other DBMS);  C7250L (Non-bibliographic systems); C6120 (File organisation) Thesaurus: Data structures; Hypermedia Free Terms: Functional meta-structure; Specific hypertext model; Trellis hypertext model; High-level hypertext reference model; R-model; Abstract levels; Concrete levels; Visible level; Hypertext-defined concepts