3,281 research outputs found
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
Secure Cloud-Edge Deployments, with Trust
Assessing the security level of IoT applications to be deployed to
heterogeneous Cloud-Edge infrastructures operated by different providers is a
non-trivial task. In this article, we present a methodology that permits to
express security requirements for IoT applications, as well as infrastructure
security capabilities, in a simple and declarative manner, and to automatically
obtain an explainable assessment of the security level of the possible
application deployments. The methodology also considers the impact of trust
relations among different stakeholders using or managing Cloud-Edge
infrastructures. A lifelike example is used to showcase the prototyped
implementation of the methodology
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
Category Theory and Model-Driven Engineering: From Formal Semantics to Design Patterns and Beyond
There is a hidden intrigue in the title. CT is one of the most abstract
mathematical disciplines, sometimes nicknamed "abstract nonsense". MDE is a
recent trend in software development, industrially supported by standards,
tools, and the status of a new "silver bullet". Surprisingly, categorical
patterns turn out to be directly applicable to mathematical modeling of
structures appearing in everyday MDE practice. Model merging, transformation,
synchronization, and other important model management scenarios can be seen as
executions of categorical specifications.
Moreover, the paper aims to elucidate a claim that relationships between CT
and MDE are more complex and richer than is normally assumed for "applied
mathematics". CT provides a toolbox of design patterns and structural
principles of real practical value for MDE. We will present examples of how an
elementary categorical arrangement of a model management scenario reveals
deficiencies in the architecture of modern tools automating the scenario.Comment: In Proceedings ACCAT 2012, arXiv:1208.430
TEMPOS: A Platform for Developing Temporal Applications on Top of Object DBMS
This paper presents TEMPOS: a set of models and languages supporting the manipulation of temporal data on top of object DBMS. The proposed models exploit object-oriented technology to meet some important, yet traditionally neglected design criteria related to legacy code migration and representation independence. Two complementary ways for accessing temporal data are offered: a query language and a visual browser. The query language, namely TempOQL, is an extension of OQL supporting the manipulation of histories regardless of their representations, through fully composable functional operators. The visual browser offers operators that facilitate several time-related interactive navigation tasks, such as studying a snapshot of a collection of objects at a given instant, or detecting and examining changes within temporal attributes and relationships. TEMPOS models and languages have been formalized both at the syntactical and the semantical level and have been implemented on top of an object DBMS. The suitability of the proposals with regard to applications' requirements has been validated through concrete case studies
Operational and abstract semantics of the query language G-Log
The amount and variety of data available electronically have dramatically increased in the led decade; however, data and documents are stored in different ways and do notusual# show their internal structure. In order to take ful advantage of thetopolk9dQ# structure ofdigital documents, andparticulIII web sites, theirhierarchical organizationshouliz explizatio introducing a notion of querysimil; to the one usedin database systems. A good approach, in that respect, is the one provided bygraphical querylrydM#99; original; designed to model object bases and lndd proposed for semistructured data, la, G-Log. The aim of this paper is to providesuitabl graph-basedsemantics to thislisd;BI# supporting both data structure variabil#I andtopol#Ik;M similpol#I between queries and document structures. A suite ofoperational semantics basedon the notion ofbisimulQM#I is introduced both at theconcr--h level (instances) andat theabstru( level (schemata), giving rise to a semantic framework that benefits from the cross-fertil9;dl of tool originalM designed in quite different research areas (databases, concurrency,loncur static analysis)
mARC: Memory by Association and Reinforcement of Contexts
This paper introduces the memory by Association and Reinforcement of Contexts
(mARC). mARC is a novel data modeling technology rooted in the second
quantization formulation of quantum mechanics. It is an all-purpose incremental
and unsupervised data storage and retrieval system which can be applied to all
types of signal or data, structured or unstructured, textual or not. mARC can
be applied to a wide range of information clas-sification and retrieval
problems like e-Discovery or contextual navigation. It can also for-mulated in
the artificial life framework a.k.a Conway "Game Of Life" Theory. In contrast
to Conway approach, the objects evolve in a massively multidimensional space.
In order to start evaluating the potential of mARC we have built a mARC-based
Internet search en-gine demonstrator with contextual functionality. We compare
the behavior of the mARC demonstrator with Google search both in terms of
performance and relevance. In the study we find that the mARC search engine
demonstrator outperforms Google search by an order of magnitude in response
time while providing more relevant results for some classes of queries
DETC2003/CIE-48228 THE DESIGN EXEMPLAR: THE FOUNDATION FOR A CAD QUERY LANGUAGE
ABSTRACT This paper seeks to identify the needs of a CAD-specific query language based upon an analysis of the essential characteristics and the tasks performed by traditional query languages. Query languages are non-procedural, high-level computer languages that are primarily focused towards retrieving data held in files and databases. They could also be used for updates, deletions, and additions Design engineers create models of design artifacts with commercial Computer Aided Design (CAD) solid modeling systems and manage the data files through Product Data Management (PDM) systems. These systems stop short of providing support for querying and retrieving data from "within" the CAD data files. A true CAD query language that allows designers the flexibility to describe queries against single and multiple CAD files would be of great benefit for design engineers. This query language ought to be both datacentric and user-centric in nature. The design exemplar, a datastructure that provides a standard representation of design knowledge based upon a general constraint validation and satisfaction algorithm, is shown here to be a concept upon which a CAD query language may be developed. The first required extension of the design exemplar is the inclusion of logical connectives. Some insights into the different levels at which the extensions may be implemented are discussed. Also, some applications retrieving geometric data using this query language are demonstrated. The query language, as it evolves, is expected to support geometric retrieval across domains and offer an all-purpose approach to geometric retrieval. The relational, or hierarchical, data model found in many legacy applications, and the query languages supporting this model, have solved problems facing most dat
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Formalizing graphical notations
The thesis describes research into graphical notations for software engineering, with a principal interest in ways of formalizing them. The research seeks to provide a theoretical basis that will help in designing both notations and the software tools that process them.
The work starts from a survey of literature on notation, followed by a review of techniques for formal description and for computational handling of notations. The survey concentrates on collecting views of the benefits and the problems attending notation use in software development; the review covers picture description languages, grammars and tools such as generic editors and visual programming environments. The main problem of notation is found to be a lack of any coherent, rigorous description methods. The current approaches to this problem are analysed as lacking in consensus on syntax specification and also lacking a clear focus on a defined concept of notated expression.
To address these deficiencies, the thesis embarks upon an exploration of serniotic, linguistic and logical theory; this culminates in a proposed formalization of serniosis in notations, using categorial model theory as a mathematical foundation. An argument about the structure of sign systems leads to an analysis of notation into a layered system of tractable theories, spanning the gap between expressive pictorial medium and subject domain. This notion of 'tectonic' theory aims to treat both diagrams and formulae together.
The research gives details of how syntactic structure can be sketched in a mathematical sense, with examples applying to software development diagrams, offering a new solution to the problem of notation specification. Based on these methods, the thesis discusses directions for resolving the harder problems of supporting notation design, processing and computer-aided generic editing. A number of future research areas are thereby opened up. For practical trial of the ideas, the work proceeds to the development and partial implementation of a system to aid the design of notations and editors. Finally the thesis is evaluated as a contribution to theory in an area which has not attracted a standard approach
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