COLAB : a hybrid knowledge representation and compilation laboratory

Knowledge bases for real-world domains such as mechanical engineering require expressive and efficient representation and processing tools. We pursue a declarative-compilative approach to knowledge engineering. While Horn logic (as implemented in PROLOG) is well-suited for representing relational clauses, other kinds of declarative knowledge call for hybrid extensions: functional dependencies and higher-order knowledge should be modeled directly. Forward (bottom-up) reasoning should be integrated with backward (top-down) reasoning. Constraint propagation should be used wherever possible instead of search-intensive resolution. Taxonomic knowledge should be classified into an intuitive subsumption hierarchy. Our LISP-based tools provide direct translators of these declarative representations into abstract machines such as an extended Warren Abstract Machine (WAM) and specialized inference engines that are interfaced to each other. More importantly, we provide source-to-source transformers between various knowledge types, both for user convenience and machine efficiency. These formalisms with their translators and transformers have been developed as part of COLAB, a compilation laboratory for studying what we call, respectively, "vertical\u27; and "horizontal\u27; compilation of knowledge, as well as for exploring the synergetic collaboration of the knowledge representation formalisms. A case study in the realm of mechanical engineering has been an important driving force behind the development of COLAB. It will be used as the source of examples throughout the paper when discussing the enhanced formalisms, the hybrid representation architecture, and the compilers

Biconic semi-copulas with a given section

Inspired by the notion of biconic semi-copulas, we introduce biconic semi-copulas with a given section. Such semi-copulas are constructed by linear interpolation on segments connecting the graph of a continuous and decreasing function to the points (0, 0) and (1, 1). Special classes of biconic semi-copulas with a given section such as biconic (quasi-)copulas with a given section are considered. Some examples are also provided

A declarative integration of terminological, constraint-based, data-driven, and goal-directed reasoning

The paper settles a research branch in the realm of logic-oriented, hybrid knowledge representation. Terminological knowledge representation and reasoning can now be utilized for more realistic applications as an integral component of a computationally complete, declarative hybrid knowledge representation formalism with integrated special-purpose reasoners of concrete domains such as real-closed fields or finite-domain constraints. The paper presents technical results exploring the impact of "role interaction" on the decidability of the subsumption problem of terminological logics. In particular, decision procedures are presented for common reasoning problems in an expressive terminological logic that is parametrized by a concrete domain. A refined minimal belief logic which avoids certain problems concerning the non-propositional case (which ocurred surprisingly) is the basis of the model-theoretic semantics of a very general generic rule formalism integrating goal-directed (i.e., top-down) and data-driven (i.e., bottom-up) reasoning in a declarative manner. A mechanical engineering application (production planning of lathes) is used to demonstrate how the theoretical results can be employed in realistic applications

Design of spacecraft for exploration of the Moon and Mars

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (p. 123-125).In this thesis, I develop the conceptual design of the spacecraft required for human-Lunar and human-Mars exploration. The requirements for these vehicles are derived in the context of the NASA Concept Exploration & Refinement project. Similarly, the concepts generated are intended to operate within the transportation architecture developed during this project. Therefore, this thesis serves as a vehicle-level design exercise. Four vehicle architecture options are synthesized by combining system concepts in a logical fashion. These four options are evaluated on several performance criteria, and one vehicle design concept is selected for detailed modeling. In addition, I investigate the conceptual design of the airlock system, as a system-level design exercise. This research project culminated in a set of vehicle concept designs and design recommendations for NASA.by Brenden P. Epps.S.M

Eine homogene Implementierungsebene für einen hybriden Wissensrepräsentationsformalismus

Im Bereich des Constraint Logic Programming gibt es einen Ansatz, Constraint Formalismen explizit über sogenannte "Constraint Simplification Rules" zu implementieren. Daran anlehnend wird eine formale Grundlage geschaffen, die es erlaubt, Regeln zum Ersetzen und Erweitern von Basismengen zu definieren. Beim Versuch, mit Hilfe solcher Regeln den Inferenzmechanismus terminologischer Sprachen - den Konsistenztest für A-Boxen - zu implementieren, stößt man an die Grenzen des Formalismus. Die klare Formalisierung ermöglicht es aber, den Regelformalismus adäquat zu erweitern. Die Handhabung dieser Erweiterung wird an einer Reihe von ganz verschiedenen Beispielen demonstriert: der Konsistenztest für A-Boxen, logische Programme, lokale Konsistenz, Unifikation, Erfüllbarkeit von Ungleichungen. Ferner wird ein Abarbeitungsmechanismus definiert, dessen Implementation in COMMON LISP im Anhang vorgestellt wird

Aeronautical Engineering: A Continuing Bibliography with Indexes (supplement 194)

This bibliography lists 369 reports, articles and other documents introduced into the NASA scientific and technical information system in November 1985

Local and global spatio-temporal entropy indices based on distance- ratios and co-occurrences distributions

When it comes to characterize the distribution of ‘things’ observed spatially and identified by their geometries and attributes, the Shannon entropy has been widely used in different domains such as ecology, regional sciences, epidemiology and image analysis. In particular, recent research has taken into account the spatial patterns derived from topological and metric properties in order to propose extensions to the measure of entropy. Based on two different approaches using either distance-ratios or co-occurrences of observed classes, the research developed in this paper introduces several new indices and explores their extensions to the spatio-temporal domains which are derived whilst investigating further their application as global and local indices. Using a multiplicative space-time integration approach either at a macro or micro-level, the approach leads to a series of spatio-temporal entropy indices including from combining co-occurrence and distances-ratios approaches. The framework developed is complementary to the spatio-temporal clustering problem, introducing a more spatial and spatio-temporal structuring perspective using several indices characterizing the distribution of several class instances in space and time. The whole approach is first illustrated on simulated data evolutions of three classes over seven time stamps. Preliminary results are discussed for a study of conflicting maritime activities in the Bay of Brest where the objective is to explore the spatio-temporal patterns exhibited by a categorical variable with six classes, each representing a conflict between two maritime activities

A revision of Strombus urceus Linné, 1758

This dissertation presents a classical revision of Strombus urceus Linne, 1758 post Abbott 1960 (Mollusca, Neostromboidae, Strombidae) and has resolved this monospecific group into twelve species. This involved a review and the presentation of novel theories in the areas of speciation, hybridisation and clade recognition