925 resultados para Multilevel Systems Model
Resumo:
Service-Oriented Architectures (SOA), and Web Services (WS), the technology generally used to implement them, achieve the integration of heterogeneous technologies, providing interoperability, and yielding the reutilization of pre-existent systems. Model-driven development methodologies provide inherent benefits such as increased productivity, greater reuse, and better maintainability, to name a few. Efforts on achieving model-driven development of SOAs already exist, but there is currently no standard solution that addresses non-functional aspects of these services as well. This paper presents an approach to integrate these non-functional aspects in the development of web services, with an emphasis on security.
Resumo:
O Teste Baseado em Modelos (TBM) emergiu como uma estratégia promissora para minimizar problemas relacionados à falta de tempo e recursos em teste de software e visa verificar se a implementação sob teste está em conformidade com sua especificação. Casos de teste são gerados automaticamente a partir de modelos comportamentais produzidos durante o ciclo de desenvolvimento de software. Entre as técnicas de modelagem existentes, Sistemas de Transição com Entrada/Saída (do inglês, Input/Output Transition Systems - IOTSs), são modelos amplamente utilizados no TBM por serem mais expressivos do que Máquinas de Estado Finito (MEFs). Apesar dos métodos existentes para geração de testes a partir de IOTSs, o problema da seleção de casos de testes é um tópico difícil e importante. Os métodos existentes para IOTS são não-determinísticos, ao contrário da teoria existente para MEFs, que fornece garantia de cobertura completa com base em um modelo de defeitos. Esta tese investiga a aplicação de modelos de defeitos em métodos determinísticos de geração de testes a partir de IOTSs. Foi proposto um método para geração de conjuntos de teste com base no método W para MEFs. O método gera conjuntos de teste de forma determinística além de satisfazer condições de suficiência de cobertura da especificação e de todos os defeitos do domínio de defeitos definido. Estudos empíricos avaliaram a aplicabilidade e eficácia do método proposto: resultados experimentais para analisar o custo de geração de conjuntos de teste utilizando IOTSs gerados aleatoriamente e um estudo de caso com especificações da indústria mostram a efetividade dos conjuntos gerados em relação ao método tradicional de Tretmans.
Resumo:
O paradigma das redes em chip (NoCs) surgiu a fim de permitir alto grau de integração entre vários núcleos de sistemas em chip (SoCs), cuja comunicação é tradicionalmente baseada em barramentos. As NoCs são definidas como uma estrutura de switches e canais ponto a ponto que interconectam núcleos de propriedades intelectuais (IPs) de um SoC, provendo uma plataforma de comunicação entre os mesmos. As redes em chip sem fio (WiNoCs) são uma abordagem evolucionária do conceito de rede em chip (NoC), a qual possibilita a adoção dos mecanismos de roteamento das NoCs com o uso de tecnologias sem fio, propondo a otimização dos fluxos de tráfego, a redução de conectores e a atuação em conjunto com as NoCs tradicionais, reduzindo a carga nos barramentos. O uso do roteamento dinâmico dentro das redes em chip sem fio permite o desligamento seletivo de partes do hardware, o que reduz a energia consumida. Contudo, a escolha de onde empregar um link sem fio em uma NoC é uma tarefa complexa, dado que os nós são pontes de tráfego os quais não podem ser desligados sem potencialmente quebrar uma rota preestabelecida. Além de fornecer uma visão sobre as arquiteturas de NoCs e do estado da arte do paradigma emergente de WiNoC, este trabalho também propõe um método de avaliação baseado no já consolidado simulador ns-2, cujo objetivo é testar cenários híbridos de NoC e WiNoC. A partir desta abordagem é possível avaliar diferentes parâmetros das WiNoCs associados a aspectos de roteamento, aplicação e número de nós envolvidos em redes hierárquicas. Por meio da análise de tais simulações também é possível investigar qual estratégia de roteamento é mais recomendada para um determinado cenário de utilização, o que é relevante ao se escolher a disposição espacial dos nós em uma NoC. Os experimentos realizados são o estudo da dinâmica de funcionamento dos protocolos ad hoc de roteamento sem fio em uma topologia hierárquica de WiNoC, seguido da análise de tamanho da rede e dos padrões de tráfego na WiNoC.
Resumo:
What explains the length of a Member of the European Parliament’s career? Little evidence of careerism has been uncovered in the European Parliament, particularly when compared to studies of legislator tenure in the U.S. Congress. Due to the different historical contexts in which these two legislatures developed, it seems reasonable to rule out many of the explanations used to account for increasing careerism in Congress in searching for the influences on legislator tenure in the European Parliament. This paper therefore proposes three potential models of careerism in the European Parliament: an electoral systems model, a party model, and an individual model. While the data necessary to test these models has not been fully compiled, this paper outlines the major hypotheses of each model and details plans for the operationalization of all independent and control variables. These models are not intended to be mutually exclusive alternatives, but rather each explanation is expected to influence each MEP in varying degrees.
Resumo:
BACKGROUND Respiratory tract infections and subsequent airway inflammation occur early in the life of infants with cystic fibrosis. However, detailed information about the microbial composition of the respiratory tract in infants with this disorder is scarce. We aimed to undertake longitudinal in-depth characterisation of the upper respiratory tract microbiota in infants with cystic fibrosis during the first year of life. METHODS We did this prospective cohort study at seven cystic fibrosis centres in Switzerland. Between Feb 1, 2011, and May 31, 2014, we enrolled 30 infants with a diagnosis of cystic fibrosis. Microbiota characterisation was done with 16S rRNA gene pyrosequencing and oligotyping of nasal swabs collected every 2 weeks from the infants with cystic fibrosis. We compared these data with data for an age-matched cohort of 47 healthy infants. We additionally investigated the effect of antibiotic treatment on the microbiota of infants with cystic fibrosis. Statistical methods included regression analyses with a multivariable multilevel linear model with random effects to correct for clustering on the individual level. FINDINGS We analysed 461 nasal swabs taken from the infants with cystic fibrosis; the cohort of healthy infants comprised 872 samples. The microbiota of infants with cystic fibrosis differed compositionally from that of healthy infants (p=0·001). This difference was also found in exclusively antibiotic-naive samples (p=0·001). The disordering was mainly, but not solely, due to an overall increase in the mean relative abundance of Staphylococcaceae in infants with cystic fibrosis compared with healthy infants (multivariable linear regression model stratified by age and adjusted for season; second month: coefficient 16·2 [95% CI 0·6-31·9]; p=0·04; third month: 17·9 [3·3-32·5]; p=0·02; fourth month: 21·1 [7·8-34·3]; p=0·002). Oligotyping analysis enabled differentiation between Staphylococcus aureus and coagulase-negative Staphylococci. Whereas the analysis showed a decrease in S aureus at and after antibiotic treatment, coagulase-negative Staphylococci increased. INTERPRETATION Our study describes compositional differences in the microbiota of infants with cystic fibrosis compared with healthy controls, and disordering of the microbiota on antibiotic administration. Besides S aureus, coagulase-negative Staphylococci also contributed to the disordering identified in these infants. These findings are clinically important in view of the crucial role that bacterial pathogens have in the disease progression of cystic fibrosis in early life. Our findings could be used to inform future studies of the effect of antibiotic treatment on the microbiota in infants with cystic fibrosis, and could assist in the prevention of early disease progression in infants with this disorder. FUNDING Swiss National Science Foundation, Fondation Botnar, the Swiss Society for Cystic Fibrosis, and the Swiss Lung Association Bern.
Resumo:
Chemical engineers are turning to multiscale modelling to extend traditional modelling approaches into new application areas and to achieve higher levels of detail and accuracy. There is, however, little advice available on the best strategy to use in constructing a multiscale model. This paper presents a starting point for the systematic analysis of multiscale models by defining several integrating frameworks for linking models at different scales. It briefly explores how the nature of the information flow between the models at the different scales is influenced by the choice of framework, and presents some restrictions on model-framework compatibility. The concepts are illustrated with reference to the modelling of a catalytic packed bed reactor. (C) 2004 Elsevier Ltd. All rights reserved.
Resumo:
Work domain analysis (WDA) has been applied to a range of complex work domains, but few WDAs have been undertaken in medical contexts. One pioneering effort suggested that clinical abstraction is not based on means-ends relations, whereas another effort downplayed the role of bio-regulatory mechanisms. In this paper it is argued that bio-regulatory mechanisms that govern physiological behaviour must be part of WDA models of patients as the systems at the core of intensive care units. Furthermore it is argued that because the inner functioning of patients is not completely known, clinical abstraction is based on hypothetico-deductive abstract reasoning. This paper presents an alternative modelling framework that conforms to the broader aspirations of WDA. A modified version of the viable systems model is used to represent the patient system as a nested dissipative structure while aspects of the recognition primed decision model are used to represent the information resources available to clinicians in ways that support lsquoif...thenrsquo conceptual relations. These two frameworks come together to form the recursive diagnostic framework, which may provide a more appropriate foundation for information display design in the intensive care unit.
Resumo:
It was hypothesized that employees' perceptions of an organizational culture strong in human relations values and open systems values would be associated with heightened levels of readiness for change which, in turn, would be predictive of change implementation success. Similarly, it was predicted that reshaping capabilities would lead to change implementation success, via its effects on employees' perceptions of readiness for change. Using a temporal research design, these propositions were tested for 67 employees working in a state government department who were about to undergo the implementation of a new end-user computing system in their workplace. Change implementation success was operationalized as user satisfaction and system usage. There was evidence to suggest that employees who perceived strong human relations values in their division at Time 1 reported higher levels of readiness for change at pre-implementation which, in turn, predicted system usage at Time 2. In addition, readiness for change mediated the relationship between reshaping capabilities and system usage. Analyses also revealed that pre-implementation levels of readiness for change exerted a positive main effect on employees' satisfaction with the system's accuracy, user friendliness, and formatting functions at post-implementation. These findings are discussed in terms of their theoretical contribution to the readiness for change literature, and in relation to the practical importance of developing positive change attitudes among employees if change initiatives are to be successful.
Resumo:
In enhanced biological phosphorus removal (EBPR) processes, glycogen-accumulating organisms (GAOs) may compete with polyphosphate-accumulating organisms (PAOs) for the often-limited carbon substrates, potentially resulting in disturbances to phosphorus removal. A detailed investigation of the effect of pH on the competition between PAOs and GAOs is reported in this study. The results show that a high external pH (similar to 8) provided PAOs with an advantage over GAOs in EBPR systems. The phosphorus removal performance improved due to a population shift favouring PAOs over GAOs, which was shown through both chemical and microbiological methods. Two lab-scale reactors fed with propionate as the carbon source were subjected to an increase in pH from 7 to 8. The phosphorus removal and PAO population (as measured by quantitative fluorescence in situ hybridisation analysis of Candidatus Accumulibacter phosphatis) increased in each system, where the PAOs appeared to out-compete a group of Alphaproteobacteria GAOs. A considerable improvement in the P removal was also observed in an acetate fed reactor, where the GAO population (primarily Candidatus Competibacter phosphatis) decreased substantially after a similar increase in the pH. The results from this study suggest that pH could be used as a control parameter to reduce the undesirable proliferation of GAOs and improve phosphorus removal in EBPR systems. (c) 2005 Elsevier Ltd. All rights reserved.
Resumo:
This study examined whether the effectiveness of human resource management (HRM)practices is contingent on organizational climate and competitive strategy The concepts of internol and external fit suggest that the positive relationship between HRM and subsequent productivity will be stronger for firms with a positive organizational climate and for firms using differentiation strategies. Resource allocation theories of motivation, on the other hand, predict that the relationship between HRM and productivity will be stronger for firms with a poor climate because employees working in these firms should have the greatest amount of spare capacity. The results supported the resource allocation argument.
Resumo:
The recent global „credit crunch? has brought sharply into focus the need for better understanding of what it takes for organisations to survive. This research seeks to help organisations maintain their „viability? – the ability to maintain a separate existence and survive on their own. Whilst there are a multitude of factors that contribute to organisational viability, information can be viewed as the lifeblood of organisations. This research increases our understanding of how organisations can manage information effectively to help maintain their viability. The viable systems model (VSM) is an established modelling technique that enables the detailed analysis of organisational activity to examine how the structure and functions performed in an organisation contribute to its „viability?. The VSM has been widely applied, in small/large companies, industries and governments. However, whilst the VSM concentrates on the structure and functions necessary for an organisation to be viable, it pays much less attention to information deployment in organisations. Indeed, the VSM is criticised in the literature for being unable to provide much help with detailed information and communication structures and new theories are called for to explore the way people interact and what information they need in the VSM. This research analyses qualitative data collected from four case studies to contribute to our understanding of the role that information plays in organisational viability, making three key contributions to the academic literature. In the information management literature, this research provides new insight into the roles that specific information plays in organisations. In the systems thinking literature, this research extends our understanding of the VSM and builds on its powerful diagnostic capability to provide further criteria to aid in the diagnosis of viable organisations. In the information systems literature, this research develops a framework that can be used to help organisations design more effective information systems.
Resumo:
This dissertation is the formulation of an argument for the incorporation of a liberated federalism perspective as the foundational theoretical construct for the teaching and study of American government and civics at the secondary level. The argument asserts that the history of the nation, in terms of its basic view of government, has developed from a traditional federalist view to a natural rights view. Instruction of government and politics has paralleled that development. The argument further asserts that the current dependence on the natural rights perspective has contributed and helped legitimize, however unintentionally, the excessive levels of individualism, self-absorption, and uncivil behavior that is being experienced in our society today.^ The argumentation follows the dialectic form presented by Hegel of thesis, antithesis, and synthesis. That is, the thesis argues that the traditional federalist perspective would serve as a viable construct for the teaching of government and civics. In this portion of the argument, the republican model of political reality is presented. The antithesis promotes the natural rights perspective and relies on the political systems model for its theoretical approach. Finally, the synthesis argues that a liberated federalism perspective should be the foundational construct. Here, the argument presents its own model as a theoretical construct that is designed to assist teachers and curriculum materials writers in the development of American government and civics lessons and materials. ^
Resumo:
The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.
Resumo:
One of the pioneer firms in the leisure cruise industry embarked on a bold idea in 2000 to offer an unregimented experience unlike most cruises. Despite the appeal of the concept from a marketing perspective, the service innovation posed operational challenges, many of which continue to undermine the firm’s competitive position. Using a multi-method empirical approach and interdisciplinary views that draw on research from marketing and operations management, the authors analyze this business case to identify challenges that service firms face when services are developed and managed from siloed functional perspectives. Based on their research findings and guided by the literature, the authors derive a service-systems model to aid service planning and management. The authors further highlight a new organizational form and function for services under the domain of service experience management that is positioned as a means to unify service operations and marketing for delivering on service promises. The authors offer direction for further research on service operations systems and service experience management.
Resumo:
O objetivo central deste trabalho interdisciplinar é verter um facho de luz sobre a relação entre a insatisfação com sistemas organizacionais e a dissonância cognitiva no atendimento a clientes. Os vendedores e seus clientes, de três unidades de uma rede de vendas de veículos autorizada a atuar no Sul do Brasil, foram selecionados para a pesquisa. Dois instrumentos de coleta de dados foram construídos pelo autor, para investigar os selecionados. Eles foram aplicados em dois momentos distintos. No primeiro, os vendedores e seus clientes responderam a questões sobre atendimento, nas diversas fases de vendas. No segundo, os vendedores responderam a questões sobre o sistema organizacional da rede, por meio de instrumento construído com base nas proposições de Spitzer (1997). A teoria bidimensional de Herzberg foi utilizada na construção da ponte entre os resultadoschave observados nas duas pesquisas. A constatação desse autor, sobre a influência da insatisfação com fatores higiênicos na motivação, foi ratificada.