59 research outputs found
DISTRIBUTED DESIGN OF HYPERMEDIA APPLICATIONS
Hypermedia technology is experiencing a rapid growth due, in large part, to
the WWW. Many hypermedia applications, especially those on the WWW
have a distributed design besides being physically spread among many servers.
A distributed design is a design that varies, albeit slightly, from instance to
instance. However, such design variances can lead to undesirable inconsistencies
that can render a hypermedia application useless. This paper explores
this problem and presents a solution based on a methodological approach
to hypermedia design and construction. The methods are illustrated via a
sample applicationInformation Systems Working Papers Serie
HYPERMEDIA, INFORMATION SYSTEMS AND ORGANIZATIONS: A RESEARCH AGENDA
Although hypermedia systems are becoming more
sophisticated and readily available as of thee shelf products,
there are few hypermedia applications within
business and industrial organizations. This paper argues
that this phenomena is rooted in the concept
of hypermedia applications as standalone programs.
Larger acceptance of hypermedia within organizations
will occur once this technology is better integrated with
other organizational systems and applied to carefully
selected tasks. The paper identifies three areas for research
in this context: the tasks perspective, which
deals with selecting tasks for which to develop hypermedia
applications, the knowledge perspective, which
deals with representing and managing the knowledge
processed by organizations, and the integration perspective,
which deals with technical issues in software
integration. This paper suggests that solutions to the
problems presented will prompt the acceptance of hypermedia
technology within organizations.Information Systems Working Papers Serie
CAN WE TRANSFORM LOGIC PROGRAMS INTO ATTRIBUTE GRAMMARS?
In this paper we study the relationship between Attribute Grammars and Logic Programs,
concentrating on transforming logic programs into attribute grammars. This
has potential applications in compilation techniques for logic programs. It does not
seem possible to transform arbitrary Logic Programs into Attribute Grammars, basically
because the same logic variables can sometimes be used as input and sometimes as
output. We introduce the notion of an Abstract Attribute Grammar, which is similar to
that of an Attribute Grammar with the exception that attributes are not classified into
inherited and synthesized, and that the semantic equations are replaced by restriction
sets. These sets represent a restriction on the values of attribute occurrences namely,
all elements within each set have to be equal. We give an effective translation schema
which produces an equivalent Abstract Attribute Grammar for a given Logic Program.
We provide a formal proof of this equivalence. We then proceed to classify a class
of Abstract Attribute Grammars that can be transformed into Attribute Grammars,
and show how to achieve this transformation. By composing both transformations one
can transform certain logic programs into attribute grammars. Complete proofs ar5e
given.Information Systems Working Papers Serie
MALUAR - A COMPUTATIONAL HYPERTEXT ENVIRONMENT
Information Systems Working Papers Serie
METHODOLOGIES FOR DESIGNING AND DEVELOPING HYPERMEDIA APPLICATIONS
Hypermedia design, as any other design activity, may be observed according to two points of view: methods which
suggest milestones to guide the designer's work and process which concerns the actual detailed behavior of the
designer at work. Cognitive studies assess that mental processes involved in any design process show widely shared
human characteristics regardless to the used design method. Thereby, they provide general keys to help designers.
Thus, a hypertext design environment should equally consider the two dimensions of a hypertext design activity, in
particular it should support the natural design process specificities, mainly the incremental and opportunist aspects.
The paper focuses on the hypertext design as a computer supported human activity. It examines what is general both
in the design methods and in the design process of hypertexts in order to determine which general features are
helpful to designers. This analysis has raised from the observation of the behavior of MacWeb users during design
tasks. It is related to sound and well known results in cognitive science. The paper also describes how the proposed
features are implemented in the MacWeb system.Information Systems Working Papers Serie
TEXT EDITING AND BEYOND: A STUDY IN LOGIC MODELING
This paper presents a logic modeling exercise in which we develop
test and implement a logic model for a test editor and use it to test
existing test editing software. We begin by presenting a first order
Horn logic axiomatization of a text editor by providing domain equations
for the primitive operations insert, delete and character retrieval. We show that this logic model captures the essential aspects of the
text editing task and how more complex features are built using these
primitives. We discuss possible implementations and conclude that
any operational semantics - the set of algorithms that perform the
task - must be strongly related to the logic model we present. In other
words, each operational semantics constitutes a model of the logic theory
Next, we illustrate the usefulness of the model by implementing
a basic text editing system and testing the correctness of an existing
text editor. We conclude by describing how we are integrating these
modeling techniques into a larger and more complex knowledge-based
system.Information Systems Working Papers Serie
ON THE SEMANTICS OF TRANSACTION TIME AND VALID TIME IN BITEMPORAL DATABASES
Numerous proposals for extending the relational data model to incorporate the temporal
dimension of data have appeared in the past several years. While most of these
have been historical databases, incorporating in some fashion a valid time dimension
to the data model and the query languages, others have been rollback databases, incorporating
a transaction time dimension, or bitemporal databases, incorporating both of
these temporal dimensions. In this paper we address an issue that has been lacking in
many of these papers, namely, a formal specification of the precise semantics of these
temporal dimensions of data. We introduce the notion of reference time - the time
that any operation is applied to the database state - and provide a logical analysis
of the interrelationships among these three temporal dimensions. We also provide an
analysis of the meaning of various variables such as now and â which have been used
in many of these models without a complete specification of their semantics.Information Systems Working Papers Serie
RMCASE: COMPUTER-AIDED SUPPORT FOR HYPERMEDIA DESIGN AND DEVELOPMENT
We present the design of a computer-aided environment, RMCase, to support the
design and construction of hypermedia applications. The environment is based upon
the Relationship Management methodology. MCase supports hypermedia design
and development activities. Support for cognitive design processes is achieved
through three fundamental premises that form the foundation of RMCase: (1) fluid
feedback loops between the various methodological stages, (2) manipulation of objects
at the instance level, and (3) lightweight prototyping . To achieve this, RMCase itself
is designed as a hypermedia application, where hypertextual navigation implements
feedback loops. Instance objects can be cloned and abstraction/instantiation
mechanisms are envisioned to facilitate designers back and forth movements between
the abstract and the concrete layers of an application. As a result, RMCase will
support bottom-up, top-down and middle-out software development styles.Information Systems Working Papers Serie
BRIDGE LAWS IN HYPERTEXT: A LOGIC MODELING APPROACH
Increasingly, computerized systems tend to delegate certain portions of their
functionality to other systems. This is routinely done by systems that use Data
Base Management Systems (DBMS) to manage their data. The DBMS is in
charge of all data related operations. A similar phenomena is emerging in the
area of graphical user-interfaces. As more of these delegation phenomena occur,
the establishment of flexible communication channels for the different applications
becomes increasingly important. We propose to achieve this communication
by establishing a set of relationships between the applications. These
relationships will be specified by bridge laws, i.e. laws that establish bridges
between different domains.
We concentrate on a particular example: coupling arbitrary applications to
a hypertext user interface. In terms of the discussion above, one of the systems
in consideration is fixed. We study the elements that are needed in order to
establish effective bridge laws. We do this by defining a general framework and
providing two examples. The first example deals with a Data Base Management
System, and the second one with a model management system. The examples
show that in order to achieve effective interaction between a system and a hypertext
interface, some meta-knowledge is required. We extrapolate from our
experiments to conclude the type of general properties of bridge laws that are
necessary to achieve this high level type of process communication.Information Systems Working Papers Serie
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