721 research outputs found
RESEARCH PROGRESS IN MIS: THE CENTER FOR RESEARCH ON INFORMATION SYSTEMS NEW YORK UNIVERSITY
Information Systems Working Papers Serie
USER INTERFACES FOR DECISION SUPPORT SYSTEMS: AN OVERVIEW
Information Systems Working Papers Serie
INFORMATION GAMES IN THE QUEST FOR MINDSHARE
The rapid growth and great popularity of Internet sites that specialize in providing
intangible services in the form of information and community services gives rise to new forms of
competition. Information Web sites such as www.how2.com and community sites such as
www.iVillage.com provide free "content" and rely on advertising and hosting revenues to
generate income. The competition between content sites in the same market niche is intense and
only a few companies are likely to survive. In this paper, we examine a
number of competitive models or "information games" that provide insights into the nature of this
competition. The models capture differences between the type and maturity of the markets and
differences in the behavioral assumptions about the nature of consumer demand for content.
While these markets often have a "winner-takes-all" nature, we find a number of situations in
which more than one player can survive at equilibrium.Information Systems Working Papers Serie
LANGUAGES FOR DECISION SUPPORT SYSTEMS: AN OVERVIEW
In this paper we survey some issues relating to the language
interfaces provided by DSS. We do this from the point-of-view of the
designer of generalized software for building DSS. We first describe a fairly general architecture for such software. This is followed by
a brief examination of the language interface components. We list the
functions that must be provided through the language facilities of a
DSS together with a number of implementation issues such as
User-friendliness, degree of procedurality and interpretation versus
compilation. This provides a useful framework for the comparative
evaluation of DSS packages. Finally we discuss some possible directions for future development including specialized formal
languages and the potential of English-like 'semi-natural' languages.Information Systems Working Papers Serie
AN INTELLIGENT SYSTEM FOR FORMULATING LINEAR PROGRAMS
The research and system development work described in this paper is aimed at overcoming some of the problems associated with the development of large, complex linear programming problems. The most overwhelming problem is that of size. It is not uncommon for large planning and policy analysis problems to have tens of thousands of constraints and activities. Matrix generator systems have been designed to help in this process. However, the amount of manual labor involved is still very great and the formulation process is subject to errors which are difficult to detect. We provide an overview of a system which uses artificial intelligence and database techniques to help a knowledgeable user formulate large linear programs. The system automates many of the tedious processes associated with large-scale modeling and provides a top-down development environment with a number of different forms of problem representation.Information Systems Working Papers Serie
REPRESENTATION SCHEMES FOR MATHEMATICAL PROGRAMMING MODELS
Because of the difficulties often experienced in formulating and
understanding large scale models, much current research is directed
towards developing systems to support the construction and
understanding of management science models. This paper discusses
seven different methods for representing mathematical programming
models during the formulation phase of the modeling process. The
approaches discussed are block-schematic, algebraic, three different
kinds of graphical schemes, a database-oriented approach and
Structured Modeling. We emphasize representations that have graphical
elements suitable for incorporation in the interface to a modeling
system. The different methods are compared using a common example and
the transformations that allow one to go from one representation to
another are discussed.Information Systems Working Papers Serie
REPRESENTATION SCHEMES FOR MATHEMATICAL PROGRAMMING MODELS
Because of the difficulties often experienced in formulating and
understanding large scale models, much current research is directed
towards developing systems to support the construction and
understanding of management science models. This paper discusses six
different methods for representing mathematical programming models
during the formulation phase of the modeling process. The approaches
discussed in the paper include algebra, three different kinds of
graphical schemes, a database-oriented approach and Structured
Modeling. We emphasize representations that have graphical elements
suitable for incorporation in the interface to a modeling system. The
different methods are compared using a common example and conclusions
are drawn as to their suitability for various modeling tasks and
situations.Information Systems Working Papers Serie
X-Ray Detection of Transient Magnetic Moments Induced by a Spin Current in Cu
We have used a MHz lock-in x-ray spectro-microscopy technique to directly
detect changes of magnetic moments in Cu due to spin injection from an adjacent
Co layer. The elemental and chemical specificity of x-rays allows us to
distinguish two spin current induced effects. We detect the creation of
transient magnetic moments of on Cu atoms
within the bulk of the 28 nm thick Cu film due to spin-accumulation. The moment
value is compared to predictions by Mott's two current model. We also observe
that the hybridization induced existing magnetic moments on Cu interface atoms
are transiently increased by about 10% or .
This reveals the dominance of spin-torque alignment over Joule heat induced
disorder of the interfacial Cu moments during current flow
COMPOSITION RULES FOR BUILDING LINEAR PROGRAMMING MODELS FROM COMPONENT MODELS
This paper describes some rules for combining component models
into complete linear programs. The objective is to lay the
foundations for systems that give users flexibility in designing
new models and reusing old ones, while at the same time,
providing better documentation and better diagnostics than
currently available. The results presented here rely on two
different sets of properties of LP models: first, the syntactic
relationships among indices that define the rows and columns of
the LP, and second, the meanings attached to these indices.
These two kinds of information allow us to build a complete
algebraic statement of a model from a collection of components
provided by the model builder.Information Systems Working Papers Serie
LPSPEC: A Language for Representing Linear Programs
Information Systems Working Papers Serie
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