366 research outputs found
The Larch/Smalltalk Interface Specification Language
Object-oriented programming languages, such as Smalltalk, help one to build reusable program modules. The reuse of program modules requires adequate documentation --- formal or informal. Larch/Smalltalk is a formal specification language for specifying such reusable Smalltalk modules. Larch/Smalltalk firmly separates specification from implementation. In Larch/Smalltalk, the unit of specification is an abstract data type, which is an abstraction of the behavior produced by one or more Smalltalk classes. A type can be a subtype of other types, which allows types to be organized based on specified behavior, and also allows for inheritance of their specifications. Larch/Smalltalk specifications are developed using specification tools integrated in the Smalltalk programming environment
Water and environmental issues
Water is a precious and finite part of the environment which is vital for socioeconomic development,
sustainability of the environment and survival. Malaysia is fortunate that it is located in a humid
tropical area rich in rainfall and water resources. The rapid economic growth of Malaysia in the past
decades is also mainly attributed to its ability to exploit abundant natural resources including water.
The exploitation of water resources is an important catalyst of economic growth but continuous
exploitation without proper management and conservation may cause the depletion of water supplies,
rendering water resources unsustainable. In recent years, water problems have escalated in Malaysia
due to climate change, urbanization and population explosion. Therefore, effective water
conservation, efficient waste water and sewage management integrated with recent technologies are
important for fostering the tandem development of economic growth and the sustainability of
environmental resources
Model-driven software engineering for construction engineering: Quo vadis?
Models are an inherent part of the construction industry, which leverages from the steady advancements in information and communication technology. One of these advancements is Building Information Modeling (BIM), which denotes the move from 2D drawings to having semantically rich models of the objects subject to construction. Additionally, the way stakeholders collaborate in construction projects and their organization is revisited. This is commonly denoted as Integrated Project Delivery (IPD). Both BIM and IPD originate from the basic principles of Lean Construction, the vision to minimize waste, increase value, and continuous improvement. The application of Model-driven Software Engineering (MDSE) to BIM is a natural choice. Although several approaches utilizing MDSE for BIM have been proposed, so far no structured overview of the current state of the art has been conducted. Such an overview is vitally needed, because the existing literature is fragmented among multiple research areas. Consequently, in this paper, we present a systematic literature review on the application of MDSE to BIM, IPD and Lean Construction resulting in a systematically derived taxonomy, which we used to classify 97 papers published between 2008 and 2018. Based on the taxonomy, we provide an analysis of the classified research showing (a) where the discourse on model-driven construction engineering currently is, (b) the state of the art of model-driven techniques in construction engineering and (c) open research challenges
An Abstract Machine for Unification Grammars
This work describes the design and implementation of an abstract machine,
Amalia, for the linguistic formalism ALE, which is based on typed feature
structures. This formalism is one of the most widely accepted in computational
linguistics and has been used for designing grammars in various linguistic
theories, most notably HPSG. Amalia is composed of data structures and a set of
instructions, augmented by a compiler from the grammatical formalism to the
abstract instructions, and a (portable) interpreter of the abstract
instructions. The effect of each instruction is defined using a low-level
language that can be executed on ordinary hardware.
The advantages of the abstract machine approach are twofold. From a
theoretical point of view, the abstract machine gives a well-defined
operational semantics to the grammatical formalism. This ensures that grammars
specified using our system are endowed with well defined meaning. It enables,
for example, to formally verify the correctness of a compiler for HPSG, given
an independent definition. From a practical point of view, Amalia is the first
system that employs a direct compilation scheme for unification grammars that
are based on typed feature structures. The use of amalia results in a much
improved performance over existing systems.
In order to test the machine on a realistic application, we have developed a
small-scale, HPSG-based grammar for a fragment of the Hebrew language, using
Amalia as the development platform. This is the first application of HPSG to a
Semitic language.Comment: Doctoral Thesis, 96 pages, many postscript figures, uses pstricks,
pst-node, psfig, fullname and a macros fil
The Discrepancy between As-Built and As-Designed in Energy Efficient Buildings: A Rapid Review
Energy efficient buildings are viewed as one of the solutions to reduce carbon emissions from the built environment. However, studies worldwide indicate that there is a significant gap between building energy targets (as-designed) and the actual measured building energy consumption (as-built). Several underlying causes for the energy performance gap have been identified at all stages of the building life cycle. Focus is generally on the post-occupancy stage of the building life cycle. However, issues relating to the construction and commissioning stages of the building are a major concern, though not usually researched. There is uncertainty on how to address the as-designed versus as-built gap. The objective of this review article is to identify causes for the energy performance gap in buildings in relation to the post-design and pre-occupancy stages and review proposed solutions. The methodology applied in this research is the rapid review, which is a variant of the systematic literature review method. Findings suggest that causes for discrepancies between as-designed and as-built energy performance during the construction and commissioning stages relate to a lack of knowledge and skills, lack of communication between stakeholders and a lack of accountability for building performance post-occupancy. Recommendations to close this gap during this period include better training, improved communication standards, collaboration, energy evaluations based on post-occupancy performance, transparency of building performance, improved testing and verification and reviewed building standards
Search improvement within the geospatial web in the context of spatial data infrastructures
El trabajo desarrollado en esta tesis doctoral demuestra que es posible mejorar la búsqueda en el contexto de las Infraestructuras de Datos Espaciales mediante la aplicación de técnicas y buenas prácticas de otras comunidades cientÃficas, especialmente de las comunidades de la Web y de la Web Semántica (por ejemplo, Linked Data). El uso de las descripciones semánticas y las aproximaciones basadas en el contenido publicado por la comunidad geoespacial pueden ayudar en la búsqueda de información sobre los fenómenos geográficos, y en la búsqueda de recursos geoespaciales en general. El trabajo comienza con un análisis de una aproximación para mejorar la búsqueda de las entidades geoespaciales desde la perspectiva de geocodificación tradicional. La arquitectura de geocodificación compuesta propuesta en este trabajo asegura una mejora de los resultados de geocodificación gracias a la utilización de diferentes proveedores de información geográfica. En este enfoque, el uso de patrones estructurales de diseño y ontologÃas en esta aproximación permite una arquitectura avanzada en términos de extensibilidad, flexibilidad y adaptabilidad. Además, una arquitectura basada en la selección de servicio de geocodificación permite el desarrollo de una metodologÃa de la georreferenciación de diversos tipos de información geográfica (por ejemplo, direcciones o puntos de interés). A continuación, se presentan dos aplicaciones representativas que requieren una caracterización semántica adicional de los recursos geoespaciales. El enfoque propuesto en este trabajo utiliza contenidos basados en heurÃsticas para el muestreo de un conjunto de recursos geopesaciales. La primera parte se dedica a la idea de la abstracción de un fenómeno geográfico de su definición espacial. La investigación muestra que las buenas prácticas de la Web Semántica se puede reutilizar en el ámbito de una Infraestructura de Datos Espaciales para describir los servicios geoespaciales estandarizados por Open Geospatial Consortium por medio de geoidentificadores (es decir, por medio de las entidades de una ontologÃa geográfica). La segunda parte de este capÃtulo desglosa la aquitectura y componentes de un servicio de geoprocesamiento para la identificación automática de ortoimágenes ofrecidas a través de un servicio estándar de publicación de mapas (es decir, los servicios que siguen la especificación OGC Web Map Service). Como resultado de este trabajo se ha propuesto un método para la identificación de los mapas ofrecidos por un Web Map Service que son ortoimágenes. A continuación, el trabajo se dedica al análisis de cuestiones relacionadas con la creación de los metadatos de recursos de la Web en el contexto del dominio geográfico. Este trabajo propone una arquitectura para la generación automática de conocimiento geográfico de los recursos Web. Ha sido necesario desarrollar un método para la estimación de la cobertura geográfica de las páginas Web. Las heurÃsticas propuestas están basadas en el contenido publicado por os proveedores de información geográfica. El prototipo desarrollado es capaz de generar metadatos. El modelo generado contiene el conjunto mÃnimo recomendado de elementos requeridos por un catálogo que sigue especificación OGC Catalogue Service for the Web, el estandar recomendado por deiferentes Infraestructuras de Datos Espaciales (por ejemplo, the Infrastructure for Spatial Information in the European Community (INSPIRE)). Además, este estudio determina algunas caracterÃsticas de la Web Geoespacial actual. En primer lugar, ofrece algunas caracterÃsticas del mercado de los proveedores de los recursos Web de la información geográfica. Este estudio revela algunas prácticas de la comunidad geoespacial en la producción de metadatos de las páginas Web, en particular, la falta de metadatos geográficos. Todo lo anterior es la base del estudio de la cuestión del apoyo a los usuarios no expertos en la búsqueda de recursos de la Web Geoespacial. El motor de búsqueda dedicado a la Web Geoespacial propuesto en este trabajo es capaz de usar como base un motor de búsqueda existente. Por otro lado, da soporte a la búsqueda exploratoria de los recursos geoespaciales descubiertos en la Web. El experimento sobre la precisión y la recuperación ha demostrado que el prototipo desarrollado en este trabajo es al menos tan bueno como el motor de búsqueda remoto. Un estudio dedicado a la utilidad del sistema indica que incluso los no expertos pueden realizar una tarea de búsqueda con resultados satisfactorios
Second CLIPS Conference Proceedings, volume 1
Topics covered at the 2nd CLIPS Conference held at the Johnson Space Center, September 23-25, 1991 are given. Topics include rule groupings, fault detection using expert systems, decision making using expert systems, knowledge representation, computer aided design and debugging expert systems
Conceptual modelling of adaptive web services based on high-level petri nets
Service technology geared by its SOA architecture and enabling Web services is
rapidly gaining in maturity and acceptance. Consequently, most worldwide
(private and corporate) cross-organizations are embracing this paradigm by
publishing, requesting and composing their businesses and applications in the
form of (web-)services. Nevertheless, to face harsh competitiveness such service oriented
cross-organizational applications are increasingly pressed to be highly
composite, adaptive, knowledge-intensive and very reliable. In contrast to that,
Web service standards such as WSDL, WSBPEL, WS-CDL and many others
offer just static, manual, purely process-centric and ad-hoc techniques to deploy
such services.
The main objective of this thesis consists therefore in leveraging the development
of service-driven applications towards more reliability, dynamically
and adaptable knowledge-intensiveness. This thesis puts forward an innovative
framework based on distributed high-level Petri nets and event-driven business
rules. More precisely, we developed a new variant of high-level Petri Nets formalism
called Service-based Petri nets (CSrv-Nets), that exhibits the following
potential characteristics. Firstly, the framework is supported by a stepwise
methodology that starts with diagrammatical UML-class diagrams and business
rules and leads to dynamically adaptive services specifications. Secondly, the
framework soundly integrates behavioural event-driven business rules and stateful
services both at the type and instance level and with an inherent distribution.
Thirdly, the framework intrinsically permits validation through guided graphical
animation. Fourthly, the framework explicitly separates between orchestrations
for modelling rule-intensive single services and choreography for cooperating
several services through their governing interactive business rules. Fifthly, the
framework is based on a two-level conceptualization: (1) the modelling of any
rule-centric service with CSrv-Nets; (2) the smooth upgrading of this service
modelling with an adaptability-level that allows for dynamically shifting up and
down any rule-centric behavior of the running business activities
Multi-Agent Systems
A multi-agent system (MAS) is a system composed of multiple interacting intelligent agents. Multi-agent systems can be used to solve problems which are difficult or impossible for an individual agent or monolithic system to solve. Agent systems are open and extensible systems that allow for the deployment of autonomous and proactive software components. Multi-agent systems have been brought up and used in several application domains
- …