860 resultados para conceptual data modelling
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Interviewer performance with respect to convincing sample members to participate in surveys is an important dimension of survey quality. However, unlike in CAPI surveys where each sample case 'belongs' to one interviewer, there are hardly any good measures of interview performance for centralised CATI surveys, where even single contacts are assigned to interviewers at random. If more than one interviewer works one sample case, it is not clear how to attribute success or failure to the interviewers involved. In this article, we propose two correlated methods to measure interviewer contact performance in centralised CATI surveys. Their modelling must take complex multilevel clustering effects, which need not be hierarchical, into account. Results are consistent with findings from CAPI data modelling, and we find that when comparing effects with a direct ('naive') measure of interviewer contact results, interviewer random effects are largely underestimated using the naive measure.
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Reading group on diverse topics of interest for the Information: Signals, Images, Systems (ISIS) Research Group of the School of Electronics and Computer Science, University of Southampton.
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La creciente importancia del uso de las aplicaciones SIG en las administraciones públicas, tanto españolas como europeas, ha dado lugar al surgimiento de diversos proyectos de desarrollo de software basados en licencias libres, cada uno de los cuales se dirige a un sector determinado de usuarios. Además, cada uno de estos proyectos define un modelo conceptual de datos para almacenar la información, servicios o módulos para el acceso a esa a información y funcionalidad que se le ofrece al usuario. La mayor parte de las veces estos proyectos se desarrollan de forma independiente a pesar de que existen interrelaciones claras entre todos ellos tales como compartir partes del modelo de datos, el interés común en dar soporte a aplicaciones de gestión municipal o el hecho de utilizar como base los mismos componentes. Estos motivos recomiendan buscar la confluencia entre los proyectos con el objetivo de evitar desarrollos duplicados y favorecer su integración e interoperabilidad. Por este motivo, en Enero de 2009 se constituyó la red signergias que busca mantener en contacto a los responsables de arquitectura y de desarrollo de estos proyectos con el fin de analizar las posibilidades de confluencia y de llegar a acuerdos que permitan compartir modelos de datos, definir de forma conjunta servicios y funcionalidades, o intercambiar componentes de software. En este artículo se describe la motivación de la creación de la red, sus objetivos, su forma de funcionamiento y los resultados alcanzados
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This review assesses the impacts, both direct and indirect, of man-made changes to the composition of the air over a 200 year period on the severity of arable crop disease epidemics. The review focuses on two well-studied UK arable crops,wheat and oilseed rape, relating these examples to worldwide food security. In wheat, impacts of changes in concentrations of SO2 in air on two septoria diseases are discussed using data obtained from historical crop samples and unpublished experimental work. Changes in SO2 seem to alter septoria disease spectra both through direct effects on infection processes and through indirect effects on soil S status. Work on the oilseed rape diseases phoma stem canker and light leaf spot illustrates indirect impacts of increasing concentrations of greenhouse gases, mediated through climate change. It is projected that, by the 2050s, if diseases are not controlled, climate change will increase yields in Scotland but halve yields in southern England. These projections are discussed in relation to strategies for adaptation to environmental change. Since many strategies take10–15 years to implement, it is important to take appropriate decisions soon. Furthermore, it is essential to make appropriate investment in collation of long-term data, modelling and experimental work to guide such decision-making by industry and government, as a contribution to worldwide food security.
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Pós-graduação em Ciências Cartográficas - FCT
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Embedded context management in resource-constrained devices (e.g. mobile phones, autonomous sensors or smart objects) imposes special requirements in terms of lightness for data modelling and reasoning. In this paper, we explore the state-of-the-art on data representation and reasoning tools for embedded mobile reasoning and propose a light inference system (LIS) aiming at simplifying embedded inference processes offering a set of functionalities to avoid redundancy in context management operations. The system is part of a service-oriented mobile software framework, conceived to facilitate the creation of context-aware applications—it decouples sensor data acquisition and context processing from the application logic. LIS, composed of several modules, encapsulates existing lightweight tools for ontology data management and rule-based reasoning, and it is ready to run on Java-enabled handheld devices. Data management and reasoning processes are designed to handle a general ontology that enables communication among framework components. Both the applications running on top of the framework and the framework components themselves can configure the rule and query sets in order to retrieve the information they need from LIS. In order to test LIS features in a real application scenario, an ‘Activity Monitor’ has been designed and implemented: a personal health-persuasive application that provides feedback on the user’s lifestyle, combining data from physical and virtual sensors. In this case of use, LIS is used to timely evaluate the user’s activity level, to decide on the convenience of triggering notifications and to determine the best interface or channel to deliver these context-aware alerts.d
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Embedded context management in resource-constrained devices (e.g. mobile phones, autonomous sensors or smart objects) imposes special requirements in terms of lightness for data modelling and reasoning. In this paper, we explore the state-of-the-art on data representation and reasoning tools for embedded mobile reasoning and propose a light inference system (LIS) aiming at simplifying embedded inference processes offering a set of functionalities to avoid redundancy in context management operations. The system is part of a service-oriented mobile software framework, conceived to facilitate the creation of context-aware applications?it decouples sensor data acquisition and context processing from the application logic. LIS, composed of several modules, encapsulates existing lightweight tools for ontology data management and rule-based reasoning, and it is ready to run on Java-enabled handheld devices. Data management and reasoning processes are designed to handle a general ontology that enables communication among framework components. Both the applications running on top of the framework and the framework components themselves can configure the rule and query sets in order to retrieve the information they need from LIS. In order to test LIS features in a real application scenario, an ?Activity Monitor? has been designed and implemented: a personal health-persuasive application that provides feedback on the user?s lifestyle, combining data from physical and virtual sensors. In this case of use, LIS is used to timely evaluate the user?s activity level, to decide on the convenience of triggering notifications and to determine the best interface or channel to deliver these context-aware alerts.
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La meta de intercambiabilidad de piezas establecida en los sistemas de producción del siglo XIX, es ampliada en el último cuarto del siglo pasado para lograr la capacidad de fabricación de varios tipos de producto en un mismo sistema de manufactura, requerimiento impulsado por la incertidumbre del mercado. Esta incertidumbre conduce a plantear la flexibilidad como característica importante en el sistema de producción. La presente tesis se ubica en el problema de integración del sistema informático (SI) con el equipo de producción (EP) en la búsqueda de una solución que coadyuve a satisfacer los requerimientos de flexibilidad impuestas por las condiciones actuales de mercado. Se describen antecedentes de los sistemas de producción actuales y del concepto de flexibilidad. Se propone una clasificación compacta y práctica de los tipos de flexibilidad relevantes en el problema de integración SI-EP, con la finalidad de ubicar el significado de flexibilidad en el área de interés. Así mismo, las variables a manejar en la solución son clasificadas en cuatro tipos: Medio físico, lenguajes de programación y controlador, naturaleza del equipo y componentes de acoplamiento. Por otra parte, la característica de reusabilidad como un efecto importante y deseable de un sistema flexible, es planteada como meta en la solución propuesta no solo a nivel aplicación del sistema sino también a nivel de reuso de conceptos de diseño. Se propone un esquema de referencia en tres niveles de abstracción, que permita manejar y reutilizar en forma organizada el conocimiento del dominio de aplicación (integración SI-EP), el desarrollo de sistemas de aplicación genérica así como también la aplicación del mismo en un caso particular. Un análisis del concepto de acoplamiento débil (AD) es utilizado como base en la solución propuesta al problema de integración SI-EP. El desarrollo inicia identificando condiciones para la existencia del acoplamiento débil, compensadores para soportar la operación del sistema bajo AD y los efectos que ocasionan en el sistema informático los cambios en el conjunto de equipos de producción. Así mismo, se introducen como componentes principales del acoplamiento los componentes tecnológico, tarea y rol, a utilizar en el análisis de los requerimientos para el desarrollo de una solución de AD entre SI-EP. La estructura de tres niveles del esquema de referencia propuesto surge del análisis del significado de conceptos de referencia comúnmente reportados en la literatura, tales como arquitectura de referencia, modelo de referencia, marco de trabajo, entre otros. Se presenta un análisis de su significado como base para la definición de cada uno de los niveles de la estructura del esquema, pretendiendo con ello evitar la ambigüedad existente debido al uso indistinto de tales conceptos en la literatura revisada. Por otra parte, la relación entre niveles es definida tomando como base la estructura de cuatro capas planteada en el área de modelado de datos. La arquitectura de referencia, implementada en el primer nivel del esquema propuesto es utilizada como base para el desarrollo del modelo de referencia o marco de trabajo para el acoplamiento débil entre el SI y el EP. La solución propuesta es validada en la integración de un sistema informático de coordinación de flujo y procesamiento de pieza con un conjunto variable de equipos de diferentes tipos, naturaleza y fabricantes. En el ejercicio de validación se abordaron diferentes estándares y técnicas comúnmente empleadas como soporte al problema de integración a nivel componente tecnológico, tales como herramientas de cero configuración (ejemplo: plug and play), estándar OPC-UA, colas de mensajes y servicios web, permitiendo así ubicar el apoyo de estas técnicas en el ámbito del componente tecnológico y su relación con los otros componentes de acoplamiento: tarea y rol. ABSTRACT The interchangeability of parts, as a goal of manufacturing systems at the nineteenth century, is extended into the present to achieve the ability to manufacture various types of products in the same manufacturing system, requirement associated with market uncertainty. This uncertainty raises flexibility as an important feature in the production system. This thesis addresses the problem regarding integration of software system (SS) and the set of production equipment (PE); looking for a solution that contributes to satisfy the requirements of flexibility that the current market conditions impose on manufacturing, particularly to the production floor. Antecedents to actual production systems as well as the concept of flexibility are described and analyzed in detail. A practical and compact classification of flexibility types of relevance to the integration SS-EP problem is proposed with the aim to delimit the meaning of flexibility regarding the area of interest. Also, a classification for the variables involved in the integration problem is presented into four types: Physical media, programming and controller languages, equipment nature and coupling components. In addition, the characteristic of reusability that has been seen as an important and desirable effect of a flexible system is taken as a goal in the proposed solution, not only at system implementation level but also at system design level. In this direction, a reference scheme is proposed consisting of three abstraction levels to systematically support management and reuse of domain knowledge (SS-PE), development of a generic system as well as its application in a particular case. The concept of loose coupling is used as a basis in the development of the proposed solution to the problem of integration SS-EP. The first step of the development process consists of an analysis of the loose coupled concept, identifying conditions for its existence, compensators for system operation under loose coupling conditions as well as effects in the software system caused by modification in the set of production equipment. In addition coupling components: technological, task and role are introduced as main components to support the analysis of requirements regarding loose coupling of SS-PE. The three tier structure of the proposed reference scheme emerges from the analysis of reference concepts commonly reported in the literature, such as reference architecture, reference model and framework, among others. An analysis of these concepts is used as a basis for definition of the structure levels of the proposed scheme, trying to avoid the ambiguity due to the indiscriminate use of such concepts in the reviewed literature. In addition, the relation between adjacent levels of the structure is defined based on the four tiers structure commonly used in the data modelling area. The reference architecture is located as the first level in the structure of the proposed reference scheme and it is utilized as a basis for the development of the reference model or loose coupling framework for SS-PE integration. The proposed solution is validated by integrating a software system (process and piece flow coordination system) with a variable set of production equipment including different types, nature and manufacturers of equipment. Furthermore, in this validation exercise, different standards and techniques commonly used have been taken into account to support the issue of technology coupling component, such as tools for zero configuration (i.e. Plug and Play), message queues, OPC-UA standard, and web services. Through this part of the validation exercise, these integration tools are located as a part of the technological component and they are related to the role and task components of coupling.
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Information systems are corporate resources, therefore information systems development must be aligned with corporate strategy. This thesis proposes that effective strategic alignment of information systems requires information systems development, information systems planning and strategic management to be united. Literature in these areas is examined, breaching the academic boundaries which separate these areas, to contribute a synthesised approach to the strategic alignment of information systems development. Previous work in information systems planning has extended information systems development techniques, such as data modelling, into strategic planning activities, neglecting techniques of strategic management. Examination of strategic management in this thesis, identifies parallel trends in strategic management and information systems development; the premises of the learning school of strategic management are similar to those of soft systems approaches to information systems development. It is therefore proposed that strategic management can be supported by a soft systems approach. Strategic management tools and techniques frame individual views of a strategic situation; soft systems approaches can integrate these diverse views to explore the internal and external environments of an organisation. The information derived from strategic analysis justifies the need for an information system and provides a starting point for information systems development. This is demonstrated by a composite framework which enables each information system to be justified according to its direct contribution to corporate strategy. The proposed framework was developed through action research conducted in a number of organisations of varying types. This suggests that the framework can be widely used to support the strategic alignment of information systems development, thereby contributing to organisational success.
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We present and evaluate a novel idea for scalable lossy colour image coding with Matching Pursuit (MP) performed in a transform domain. The idea is to exploit correlations in RGB colour space between image subbands after wavelet transformation rather than in the spatial domain. We propose a simple quantisation and coding scheme of colour MP decomposition based on Run Length Encoding (RLE) which can achieve comparable performance to JPEG 2000 even though the latter utilises careful data modelling at the coding stage. Thus, the obtained image representation has the potential to outperform JPEG 2000 with a more sophisticated coding algorithm.
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Dimensional and form inspections are key to the manufacturing and assembly of products. Product verification can involve a number of different measuring instruments operated using their dedicated software. Typically, each of these instruments with their associated software is more suitable for the verification of a pre-specified quality characteristic of the product than others. The number of different systems and software applications to perform a complete measurement of products and assemblies within a manufacturing organisation is therefore expected to be large. This number becomes even larger as advances in measurement technologies are made. The idea of a universal software application for any instrument still appears to be only a theoretical possibility. A need for information integration is apparent. In this paper, a design of an information system to consistently manage (store, search, retrieve, search, secure) measurement results from various instruments and software applications is introduced. Two of the main ideas underlying the proposed system include abstracting structures and formats of measurement files from the data so that complexity and compatibility between different approaches to measurement data modelling is avoided. Secondly, the information within a file is enriched with meta-information to facilitate its consistent storage and retrieval. To demonstrate the designed information system, a web application is implemented. © Springer-Verlag Berlin Heidelberg 2010.
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Safety on public transport is a major concern for the relevant authorities. We
address this issue by proposing an automated surveillance platform which combines data from video, infrared and pressure sensors. Data homogenisation and integration is achieved by a distributed architecture based on communication middleware that resolves interconnection issues, thereby enabling data modelling. A common-sense knowledge base models and encodes knowledge about public-transport platforms and the actions and activities of passengers. Trajectory data from passengers is modelled as a time-series of human activities. Common-sense knowledge and rules are then applied to detect inconsistencies or errors in the data interpretation. Lastly, the rationality that characterises human behaviour is also captured here through a bottom-up Hierarchical Task Network planner that, along with common-sense, corrects misinterpretations to explain passenger behaviour. The system is validated using a simulated bus saloon scenario as a case-study. Eighteen video sequences were recorded with up to six passengers. Four metrics were used to evaluate performance. The system, with an accuracy greater than 90% for each of the four metrics, was found to outperform a rule-base system and a system containing planning alone.
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An important feature of some conceptual modelling grammars is the features they provide to allow database designers to show real-world things may or may not possess a particular attribute or relationship. In the entity-relationship model, for example, the fact that a thing may not possess an attribute can be represented by using a special symbol to indicate that the attribute is optional. Similarly, the fact that a thing may or may not be involved in a relationship can be represented by showing the minimum cardinality of the relationship as zero. Whether these practices should be followed, however, is a contentious issue. An alternative approach is to eliminate optional attributes and relationships from conceptual schema diagrams by using subtypes that have only mandatory attributes and relationships. In this paper, we first present a theory that led us to predict that optional attributes and relationships should be used in conceptual schema diagrams only when users of the diagrams require a surface-level understanding of the domain being represented by the diagrams. When users require a deep-level understanding, however, optional attributes and relationships should not be used because they undermine users' abilities to grasp important domain semantics. We describe three experiments which we then undertook to test our predictions. The results of the experiments support our predictions.
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At the moment there is a lack of methodological approaches to formalization of management of innovative projects relating to production systems, as well as to adaptation and practical use of the existing approaches. This article is about one potential approach to the management of innovative projects, which makes the building of innovative process models possible based on objective approach. It outlines the frameworks for the building of innovative project models, and describes the method of transition from conceptual modelling to innovative project management. In this case, the model alone and together with parameters used for evaluation of the project may be unique and depends on the special features of the project, preferences of decision-making person, and production and economic system in which it is to be implemented. Unlike existing approaches, this concept does not place any restrictions on types of models and makes it possible to take into account the specificities of economic and production systems. Principles embodied in the model allow its usage as a basis for simulation model to be used in one of specialized simulation systems, as well as for information system providing information support of decision-making process in production and economic systems both newly developed by the company (enterprise) and designed on the basis of available information systems that interact through the exchange of data. In addition, this article shows that the development of conceptual foundations of innovative project management in the economic and production systems is inseparable from the development of the theory of industrial control systems, and their comprehensive study may be reduced to a set of elements represented as certain algorithms, models and evaluations. Thus, the study of innovative process may be conducted in both directions: from general to particular, and vice versa.