• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 37
  • 13
  • 12
  • 3
  • 3
  • 3
  • 2
  • 1
  • Tagged with
  • 98
  • 22
  • 22
  • 15
  • 14
  • 14
  • 13
  • 13
  • 10
  • 10
  • 10
  • 9
  • 9
  • 9
  • 9
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Influence of Physiological State, Prolonged Dry Storage, and Passage through Simulated Digestion on the Survival and Gene Expression of Salmonella enterica sv. Tennessee

Aviles, Bryan 04 June 2012 (has links)
Salmonella enterica serotypes have been linked to outbreaks associated with low water activity foods. The ability of biofilm forming pathogens, such as Salmonella, to survive thermal and chemical processes is improved; it is unclear if biofilms will also improve survival to desiccation and gastric stresses. The purpose of this study was to quantify the effect of physiological state (planktonic versus biofilm) and prior exposure to desiccation on Salmonella survival and gene expression after passage through an in-vitro digestion model. Cells of Salmonella enterica serotype Tennessee were deposited onto membranes for planktonic cells or on glass beads to create biofilms. The cells were subsequently dried at room temperature and stored in dried milk powder (aw = 0.3) for up to 30 days. Salmonella survival was quantified by serial dilution onto brilliant green agar before desiccation, after desiccation, after 1-day storage and after 30-day storage. At each sampling both physiological states were tested for survival through a simulated gastrointestinal system. RNA was extracted at the identical time points and relative gene expression determined for genes associated with stress response (rpoS, otsB), virulence (hilA, hilD, invA, sipC) and a housekeeping gene 16S rRNA using quantitative real-time PCR. The physiological state and length of storage effected the survival and gene expression of Salmonella within the desiccated milk powder environment and after passage through an in-vitro digestion system (p<0.05). Larger numbers of S. Tennessee were recovered by plate counts for biofilm cells, compared to planktonic cells. However, the numbers of 16S rRNA gene copies were not significantly different suggesting entry of S. Tennessee into a viable but non-culturable state. Prolonged storage in dry milk powder was not associated with increased cross-protection to gastric stress. Increased expression of stress response genes rpoS and otsB correlated with survival, indicating cross protection of low water activity and acid stress. Increased expression of virulence-associated genes was seen in cells exposed to short periods of dry storage, suggesting an increased virulence potential. / Master of Science in Life Sciences
62

Fungal DNA, Mould, Dampness and Allergens in Schools and Day Care Centers and Respiratory Health

Cai, Guihong January 2013 (has links)
Day care centers and schools are important environments for children, but few epidemiological studies exist from these environments. Mould, dampness, fungal DNA and allergens levels in these environments and respiratory health effects in school children were investigated in this thesis. In the day care centers studies, Allergen Avoidance Day care Centers (AADCs) and Ordinary Day care Centers were included. One third of the Swedish day care centers had a history of dampness or mould growth. Total fungal DNA levels were positively associated with risk construction buildings, reported dampness/moulds, rotating heat exchangers, linoleum floors and allergens (cat, dog, horse allergen) levels. The two school studies included secondary schools in Johor Bahru, Malaysia and elementary schools from five European countries (Italy, Denmark, Sweden, Norway, and France) (HESE-study). In Malaysia, 13 % of the pupils reported doctor-diagnosed asthma but only 4 % had asthma medication. The prevalence of wheeze in the last 12 months was 10 % in Malaysia and 13 % in the HESE-study. Cough and rhinitis were common among children in the HESE-study. There were associations between fungal DNA and reported dampness or mould growth. Fungal DNA levels and viable mould (VM) concentration in the classrooms were associated with respiratory symptoms (wheeze, rhinitis, cough, daytime breathlessness) in school children. In the HESE-study, associations were found between total fungal DNA, Aspergillus/Penicillium DNA and respiratory symptoms among children. Moreover, Aspergillus versicolor DNA and Streptomyces DNA were associated with respiratory symptoms in Malaysia and the HESE-study, as well as reduced lung function [forced vitality capacity (FVC) and forced expiratory volume in 1 second (FEV1)] among children in the HESE-study. In conclusion, fungal DNA and pet allergens were common in day care centers and schools and respiratory symptoms in school children were common. The associations between VM concentration and fungal DNA levels in the schools and respiratory health effects in school children indicated a need for improvement of these environments. Moreover, risk constructions should be avoided and buildings should be maintained to avoid dampness and microbial growth. Health relevance of microbial exposure and biodiversity needs to be further studied using molecular methods.
63

Utilizing Valvetrain Flexibility to Influence Gas Exchange and Reduce Reliance on Exhaust Manifold Pressure Control for Efficient Diesel Engine Operation

Kalen Vos (6787271) 02 August 2019 (has links)
Environmental health awareness has elevated in recent years alongside the evidence that supports the need to mitigate harmful greenhouse gas (GHG) emissions from non-renewable energy resources. The transportation sector alone significantly contributes to the pollutants on a global scale. Although it is commonly used for its superior energy-density and fuel efficiency, diesel engines are a significant portion of the transportation sector that contributes to these pollutants. As a result, this motivates novel research to simultaneously drive fuel efficiency improvements and emissions reductions. <div><br></div><div>The aftertreatment system for a diesel engine is critical in reducing the amount of harmful tailpipe emissions. Efficient operation of these aftertreatment systems generally requires elevated temperatures of 250◦C or above. In this effort, a flexible valvetrain will be utilized to demonstrate fuel-efficient strategies via intake valve closure (IVC) modulation at elevated speeds and loads. In addition, thermal management strategies will be demonstrated at low-to-moderate loads via cylinder deactivation (CDA), cylinder cutout, exhaust valve opening (EVO) modulation, and high-speed idle operation.</div><div><br></div><div>At elevated engine speeds, late intake valve closure (LIVC) enables improved cylinder filling via a dynamic charging effect. It is experimentally and analytically demonstrated that LIVC at 2200 RPM and 7.6 bar to 12.7 bar BMEP can be used to increase the volumetric efficiency and enable higher exhaust gas recirculation fractions without penalizing the air-to-fuel ratio. As a result, efficiency improving injection advances are implemented to achieve 1.2% and 1.9% fuel savings without sacrificing NOx penalties. In order to implement the LIVC benefits on a cammed engine, production-viable valve profile solutions were investigated. It is demonstrated that lost-motion-enabled and/or added-motion-enabled boot shape profiles are capable of improving volumetric efficiency at elevated engine speeds and loads. These profiles were also considered for one (of two) -valve modulation and two-valve modulation. Nearly 95% of the volumetric efficiency benefits are possible using production-viable boot or phase profiles, while 80% of the benefits are possible for single-valve modulation. </div><div><br></div><div>At curb idle, CDA and cylinder cutout operation realize stay-warm aftertreatment thermal management improvements by leveraging their impact on the gas exchange process. Specifically, cylinder cutout demonstrates 17% fuel savings, while CDA demonstrates 40% fuel savings, over the conventional six-cylinder thermal calibration. Additionally, the performance of cylinder cutout is subject to the geometry of the exhaust manifold, location of the EGR loop, and ability to control the exhaust manifold pressure. </div><div><br></div><div>Elevating the idle speed, while maintaining the same idle load, enables improved aftertreatment warm-up performance with engine-out NOx and PM levels no higher than a state-of-the-art thermal calibration at conventional idle operation. Elevated idle speeds of 1000RPM and 1200 RPM, compared to conventional idle at 800 RPM, realized 31% to 51% increase in exhaust flow and 25◦C to 40◦C increase in engine-out temperature, respectively. Additional engine-out temperature benefits are experimentally demonstrated at all three idle speeds considered (800, 1000, and 1200 RPM), without compromising the exhaust flow rates or emissions, by modulating the EVO timing. </div><div><br></div><div>At low-to-moderate loads modern diesel engines manipulate exhaust manifold pressures to drive EGR and thermally manage the aftertreatment. In these engines exhaust manifold pressure control is typically achieved via either a valve after the turbine, a variable geometry turbine, or wastegating. It is experimentally demonstrated that valvetrain flexibility enables efficient engine and aftertreatment operation without requiring exhaust manifold pressure control. Specifically, IVC modulation and CDA at elevated engine speeds, along with EVO modulation, CDA, and internal EGR at low engine speeds can match, or improve, efficiency and thermal management performance compared to a stock thermal calibration that requires exhaust manifold pressure control.<br></div>
64

A natureza sistêmica das capacidades dinâmicas: uma abordagem evolutiva à estratégia organizacional / The systemic nature of dynamic capabilities: an evolutionary approach to organizational strategy

Donaires, Omar Sacilotto 18 September 2018 (has links)
A teoria sobre as capacidades dinâmicas acolhe influências de várias teorias que a antecederam no campo da economia, da teoria das organizações e da estratégia. Em função dessas influências variadas, seu construto central, a capacidade dinâmica, tornou-se complexo e multifacetado. Vários autores especulam acerca da natureza e da evolução das capacidades dinâmicas. A percepção que se tem a partir das definições fornecidas pelos autores seminais é de que a natureza das capacidades dinâmicas é sistêmica e evolutiva. Em particular, é perceptível a afinidade do conceito de capacidades dinâmicas com duas abordagens sistêmicas específicas: o modelo do sistema viável (viable system model, VSM) e a metodologia sistêmica soft (soft systems methodology, SSM). Entretanto, apesar dessa aparente afinidade das capacidades dinâmicas com a visão sistêmica, estudos que relacionem os dois domínios da literatura são muito raros. Praticamente inexistem trabalhos que apliquem o VSM ou a SSM no estudo ou na administração de capacidades dinâmicas. O objetivo desta pesquisa é investigar a natureza e a evolução das capacidades dinâmicas sob uma perspectiva sistêmico-evolutiva. Como descrever a natureza das capacidades dinâmicas segundo uma perspectiva sistêmico-evolutiva? Como operacionalizar uma abordagem de administração evolutiva de capacidades dinâmicas através de metodologias sistêmicas como o VSM e a SSM? Essas são as perguntas que orientam este estudo. Através de revisão narrativa de literatura, a visão de capacidades dinâmicas e as teorias que a influenciaram foram analisadas e relacionadas com a visão sistêmica. Além disso, na falta de artigos que relacionassem os dois domínios da literatura, empreendeu-se uma revisão integrativa de literatura com artigos que tratam sobre a construção, desenvolvimento, evolução, obtenção, manutenção, mobilização e gerenciamento de capacidades dinâmicas. Esses artigos foram submetidos à análise categorial, uma variante da análise de conteúdo, para verificar a ocorrência de temas relacionados ao VSM e à SSM. Como resultado da revisão narrativa, demonstrou-se que a visão de capacidades dinâmicas está intimamente relacionada com a visão sistêmica, inclusive com o VSM e a SSM. Essa relação é uma herança da relação que as teorias que influenciaram a visão de capacidades dinâmicas já possuíam com a visão sistêmica. A revisão integrativa de literatura com análise de conteúdo permitiu concluir que (1) as capacidades dinâmicas têm, de fato, uma natureza evolutiva, (2) a intervenção da administração tem um papel importante na construção e na evolução de capacidades dinâmicas, e (3) essa intervenção pode ocorrer de duas maneiras básicas, que se chamou de evolução por projeto e evolução por aprendizagem, que se relacionou, respectivamente, às abordagens do VSM e da SSM. As descobertas da pesquisa foram sintetizadas em um modelo sistêmico evolutivo de organização que possui múltiplas vistas: um modelo hierárquico de administração de recursos e capacidades, um modelo recursivo de competências, um modelo recursivo de capacidades, um modelo de evolução de capacidades e um modelo de administração evolutiva baseado no VSM e na SSM. A pesquisa oferece uma contribuição teórica, no que diz respeito à compreensão da natureza sistêmica das capacidades dinâmicas. A pesquisa também oferece uma contribuição prática, ao propor a administração evolutiva, operacionalizada através do VSM e da SSM, como uma abordagem para o gerenciamento das capacidades dinâmicas. / The theory of dynamic capabilities gathers influences from several theories that preceded it in the fields of economics, organizational theory and strategy. Due to these varied influences, its core construct, the dynamic capability, ended up to become complex and multifaceted. Several authors speculate about the nature and the evolution of dynamic capabilities. The perception that we have from the definitions provided by the seminal authors is that the nature of dynamic capabilities is systemic and evolutionary. In particular, it is noticeable the affinity of the dynamic capability concept with two specific systems approaches: the viable system model (VSM) and the soft systems methodology (SSM). However, despite this seemingly affinity of dynamic capabilities with systems approach, studies that relate both realms of the literature are very scarce. There are practically no studies that apply the VSM or SSM in the study or the management of dynamic capabilities. The goal of the present research is to investigate the nature and the evolution of dynamic capabilities under a systemic-evolutionary approach. How to conceive the nature of dynamic capabilities according to a systemic-evolutionary perspective? How to operationalize an evolutionary management approach to dynamic capabilities by using systems methodologies such as the VSM and SSM? These are the questions that drive this research. By means of a narrative literature review, the dynamic capabilities view and the theories that influenced it were analyzed and related with systems thinking. In addition, given the lack of articles that relate both realms of the literature, an integrative literature review was undertaken with articles that address the construction, development, evolution, attainment, maintenance, deployment and management of dynamic capabilities. These articles were submitted to categorical analysis, a variation of content analysis, to verify the occurrence of themes related to the VSM and SSM. As a result of the narrative literature review, we showed that the dynamic capabilities view is closely related to the systems thinking, including to the VSM and SSM. This relation in an inheritance of the relation that the theories that influenced the dynamic capabilities view already had with systems thinking. The integrative literature review with content analysis led to the conclusion that (1) the dynamic capabilities do have an evolutionary nature, (2) the intervention of management has an important role in building and evolving dynamic capabilities, and (3) this intervention can take two basic approaches, that we named evolution by design and evolution by learning, which we respectively related to the approaches of the VSM and SSM. The findings of the research were synthesized in a evolutionary system model of the organization that has several multiple views: a hierarchical model for resources management, a recursive model of competences, a recursive model of capabilities, a capabilities evolution model and a model for evolutionary management based on the VSM and SSM. The research provides a theoretical contribution, which regards the understanding of the systemic nature of dynamic capabilities. The research also provides a practical contribution, as it proposes evolutionary management, operationalized by applying the VSM and SSM, as an approach to the management of the dynamic capabilities.
65

O modelo do sistema viável na concepção da arquitetura de sistemas de informação: aplicação no contexto de incidentes em instalação de pesquisa na área nuclear. / The Viable System Model (VSM) in the conception of information system architectures - an application in the context of incidents for a research nuclear installation.

Hampshire, Maria Cláudia Santiago 10 November 2008 (has links)
O trabalho apresenta um estudo com a finalidade de verificar a aplicabilidade do Modelo do Sistema Viável (VSM Viable System Model) no projeto de uma arquitetura robusta de um Sistema de Informação voltado à área naval nuclear. A ênfase do estudo está em avaliar uma modelagem alternativa para a especificação da arquitetura do Sistema de Informação, incorporando o conjunto de funcionalidades especificadas pelo VSM, com o objetivo de fortalecer esta arquitetura. A estratégia desta pesquisa baseia-se em uma revisão bibliográfica relacionada ao VSM, aos Sistemas de Informação e a sua arquitetura, e às influências destes elementos na sobrevivência das organizações diante das mudanças constantes no ambiente. É apresentado um estudo de caso onde são mostrados os elementos teóricos do VSM e da arquitetura de SI aplicados na elaboração da arquitetura de um SI. O Sistema escolhido para esta aplicação é o Sistema de informação de incidentes nucleares (SIN) nas instalações onde são feitas pesquisas e desenvolvimento de tecnologia nuclear a ser aplicada na propulsão de um submarino. / The present work presents a study aiming to verify the applicability of the Viable System Model (VSM) in a robust architecture for an Information System targeting nuclear naval area. The emphasis of the study is in assessing an alternative modeling for the Information System (IS) architecture specification, incorporating a set of functionalities defined by the VSM, with the purpose of strengthening this architecture. The strategy of this research is based on a bibliographic revision on VSM, Information System and its architecture, and the influence of those elements in the survival of the organizations in a ever changing environment. It is presented one case study where it is showed the theoretical elements of the VSM and IS architecture applied on the development of a IS architecture. The selected system for this application is the IS for nuclear incidents (SIN) on the installations dedicated to research and development on nuclear technology applied to submarine propulsion system.
66

Novel approaches for risk management of Legionella bacteria in domestic water systems

Peter, Aji January 2018 (has links)
Legionella pneumophila, the causative agent of Legionnaires' disease, is a water born pathogenic bacteria commonly found in natural and manmade water systems such as rivers, lakes, wet soil, hot and cold water storage systems (being able to survive at temperatures between 6-63 °C, and proliferating between 20-45 °C), showerheads, cooling towers and spa pools. The main pathway of exposure to Legionella is by inhaling the aerosols containing the microorganism. Legionnaires' disease can be fatal if not diagnosed and treated at the right time. Practical Legionella control starts with a risk assessment of the water system and followed by the regular monitoring and water sampling. UK Health and Safety Executive (HSE) have implemented strict legislations to protect the public from Legionnaires' disease. This research highlights and addresses three major data gaps identified in Legionella control and management strategy employed in the UK and worldwide; namely, (i) the underestimation of microbiological threat in current cold water storage sampling strategy, (ii) the inability of current qPCR diagnostic methods to detect live Legionella in water samples, and (iii) the lack of predictive 'risk management system' for Legionella control in domestic water systems. During my PhD, 15 relevant cold water storage tanks (selected from more than 6000 tanks surveyed at different sites located in different London Boroughs) were used to investigate the risk factors that contribute towards Legionella proliferation, and revealed serious shortcomings in the appropriateness of the water sample taken for regulatory testing. Secondly, molecular biology research was carried out to develop an accurate, reliable and rapid testing method for the detection and quantification of live Legionella using qPCR techniques. This was successfully achieved by extracting RNA from a Legionella lenticule, converting the RNA into cDNA and amplifying the cDNA using qPCR techniques. Finally, regular monitoring data from 120 London buildings (60 known to be Legionella positive and 60 known to be Legionella negative) was used to identify the possible risk factors contributing towards Legionella outbreaks. Data for these factors was then used to develop a predictive risk model for Legionella contamination using Principal Component Analysis (PCA). The model was validated with 66 new London buildings and 9 out of London buildings. The model showed 100% accuracy in predicting the risk of Legionella by distinguishing infected and non-infected sites in London as well as for the sites in out of London.
67

A natureza sistêmica das capacidades dinâmicas: uma abordagem evolutiva à estratégia organizacional / The systemic nature of dynamic capabilities: an evolutionary approach to organizational strategy

Omar Sacilotto Donaires 18 September 2018 (has links)
A teoria sobre as capacidades dinâmicas acolhe influências de várias teorias que a antecederam no campo da economia, da teoria das organizações e da estratégia. Em função dessas influências variadas, seu construto central, a capacidade dinâmica, tornou-se complexo e multifacetado. Vários autores especulam acerca da natureza e da evolução das capacidades dinâmicas. A percepção que se tem a partir das definições fornecidas pelos autores seminais é de que a natureza das capacidades dinâmicas é sistêmica e evolutiva. Em particular, é perceptível a afinidade do conceito de capacidades dinâmicas com duas abordagens sistêmicas específicas: o modelo do sistema viável (viable system model, VSM) e a metodologia sistêmica soft (soft systems methodology, SSM). Entretanto, apesar dessa aparente afinidade das capacidades dinâmicas com a visão sistêmica, estudos que relacionem os dois domínios da literatura são muito raros. Praticamente inexistem trabalhos que apliquem o VSM ou a SSM no estudo ou na administração de capacidades dinâmicas. O objetivo desta pesquisa é investigar a natureza e a evolução das capacidades dinâmicas sob uma perspectiva sistêmico-evolutiva. Como descrever a natureza das capacidades dinâmicas segundo uma perspectiva sistêmico-evolutiva? Como operacionalizar uma abordagem de administração evolutiva de capacidades dinâmicas através de metodologias sistêmicas como o VSM e a SSM? Essas são as perguntas que orientam este estudo. Através de revisão narrativa de literatura, a visão de capacidades dinâmicas e as teorias que a influenciaram foram analisadas e relacionadas com a visão sistêmica. Além disso, na falta de artigos que relacionassem os dois domínios da literatura, empreendeu-se uma revisão integrativa de literatura com artigos que tratam sobre a construção, desenvolvimento, evolução, obtenção, manutenção, mobilização e gerenciamento de capacidades dinâmicas. Esses artigos foram submetidos à análise categorial, uma variante da análise de conteúdo, para verificar a ocorrência de temas relacionados ao VSM e à SSM. Como resultado da revisão narrativa, demonstrou-se que a visão de capacidades dinâmicas está intimamente relacionada com a visão sistêmica, inclusive com o VSM e a SSM. Essa relação é uma herança da relação que as teorias que influenciaram a visão de capacidades dinâmicas já possuíam com a visão sistêmica. A revisão integrativa de literatura com análise de conteúdo permitiu concluir que (1) as capacidades dinâmicas têm, de fato, uma natureza evolutiva, (2) a intervenção da administração tem um papel importante na construção e na evolução de capacidades dinâmicas, e (3) essa intervenção pode ocorrer de duas maneiras básicas, que se chamou de evolução por projeto e evolução por aprendizagem, que se relacionou, respectivamente, às abordagens do VSM e da SSM. As descobertas da pesquisa foram sintetizadas em um modelo sistêmico evolutivo de organização que possui múltiplas vistas: um modelo hierárquico de administração de recursos e capacidades, um modelo recursivo de competências, um modelo recursivo de capacidades, um modelo de evolução de capacidades e um modelo de administração evolutiva baseado no VSM e na SSM. A pesquisa oferece uma contribuição teórica, no que diz respeito à compreensão da natureza sistêmica das capacidades dinâmicas. A pesquisa também oferece uma contribuição prática, ao propor a administração evolutiva, operacionalizada através do VSM e da SSM, como uma abordagem para o gerenciamento das capacidades dinâmicas. / The theory of dynamic capabilities gathers influences from several theories that preceded it in the fields of economics, organizational theory and strategy. Due to these varied influences, its core construct, the dynamic capability, ended up to become complex and multifaceted. Several authors speculate about the nature and the evolution of dynamic capabilities. The perception that we have from the definitions provided by the seminal authors is that the nature of dynamic capabilities is systemic and evolutionary. In particular, it is noticeable the affinity of the dynamic capability concept with two specific systems approaches: the viable system model (VSM) and the soft systems methodology (SSM). However, despite this seemingly affinity of dynamic capabilities with systems approach, studies that relate both realms of the literature are very scarce. There are practically no studies that apply the VSM or SSM in the study or the management of dynamic capabilities. The goal of the present research is to investigate the nature and the evolution of dynamic capabilities under a systemic-evolutionary approach. How to conceive the nature of dynamic capabilities according to a systemic-evolutionary perspective? How to operationalize an evolutionary management approach to dynamic capabilities by using systems methodologies such as the VSM and SSM? These are the questions that drive this research. By means of a narrative literature review, the dynamic capabilities view and the theories that influenced it were analyzed and related with systems thinking. In addition, given the lack of articles that relate both realms of the literature, an integrative literature review was undertaken with articles that address the construction, development, evolution, attainment, maintenance, deployment and management of dynamic capabilities. These articles were submitted to categorical analysis, a variation of content analysis, to verify the occurrence of themes related to the VSM and SSM. As a result of the narrative literature review, we showed that the dynamic capabilities view is closely related to the systems thinking, including to the VSM and SSM. This relation in an inheritance of the relation that the theories that influenced the dynamic capabilities view already had with systems thinking. The integrative literature review with content analysis led to the conclusion that (1) the dynamic capabilities do have an evolutionary nature, (2) the intervention of management has an important role in building and evolving dynamic capabilities, and (3) this intervention can take two basic approaches, that we named evolution by design and evolution by learning, which we respectively related to the approaches of the VSM and SSM. The findings of the research were synthesized in a evolutionary system model of the organization that has several multiple views: a hierarchical model for resources management, a recursive model of competences, a recursive model of capabilities, a capabilities evolution model and a model for evolutionary management based on the VSM and SSM. The research provides a theoretical contribution, which regards the understanding of the systemic nature of dynamic capabilities. The research also provides a practical contribution, as it proposes evolutionary management, operationalized by applying the VSM and SSM, as an approach to the management of the dynamic capabilities.
68

Viable Software: the Intelligent Control Paradigm for Adaptable and Adaptive Architecture

Herring, Charles Edward Unknown Date (has links)
The Intelligent Control Paradigm for software architecture is the result of this work. The Viable Software Approach is developed as an instance of the paradigm. The approach uses the Viable System Model as the basis for software system architecture. The result is a model-based architecture and approach for developing software systems by piecemeal adaptation with the goal that they become adaptive systems at runtime. Software built in this manner is called Viable Software. Viable Software represents a unifying class of self-controlling software that is an “intelligent” control system. Cybernetics, Control Theory, and Complexity Theory are the background for this work, and aspects relevant to this work are presented. These results are related to software architecture and software engineering. Rationale for the selection of the Viable System Model as a basis for software systems is given. The Viable System Model is described. The model is restated as an Alexanderian “pattern language” to make it more accessible to software engineering. A Viable Software Approach is proposed and expressed in the form of a Product Line Architecture that arranges the Viable System Model, the Viable Software Architecture, a Viable Component Framework, and a Component Transfer Protocol into a system for generative programming. An important result is the formalisation of the pattern of the Viable System into the interface specifications of the Viable Component. Three case studies illustrate the approach. The first is an analysis and extension of the Groove collaboration system. This study shows how the approach is used to map an existing system into the Viable Software Architecture and add fuzzy-adaptive user interface controllers. The second study presents the design and detailed software construction of an adaptive camera controller as part of a smart environment. The final study shows how a Business-to-Business e-Commerce system can be evolved and an expert system-based controller developed to implement business contracts.
69

Designing Intranets for Viability : Approaching Organizational Empowerment and Participation

Nyström, Christina Amcoff January 2006 (has links)
<p>Intranets appeared in the mid-1990s and were perceived as the answer to the need for the integration of existing Information Systems into organisations. Despite the fact that there has been extensive research regarding implementation, development processes, policies standardisation vs. creativity and so forth, the potentiality of Intranets has not been fully exploited. Intranets offer many advantages in the form of working networks that support and enable empowered employees to participate in the development of the organisation, to enable the measurement of essential functions and to monitor undesired conditions and find suitable functions that support daily work. The research approach in this thesis has alternated between analysis empirical studies, and design. Current literature, research findings in the form of articles, etc., are analysed, an empirical study of five organisations is conducted and finally a design of possible functions is accomplished. In the analysis of the state-of-the-art, current research can be grouped into four topics partly overlapping each other; questions concerning informatics, organisation theory, knowledge management, and design. Urgent issues for further research are identified as mainly belonging to the topics informatics and organisation theory; management and strategy, empowerment, further development processes, use, and roles. Findings from a study of five Swedish organisations show a need for identifying the philosophy of technology in the organisations in order to make an organisation’s view of technology common throughout the organisation. Furthermore, functions supporting daily work are lacking to a high degree. Further lacks and demands are identified, as well as potential functions and new possibilities. In the next section, the Philosophy of Technology is related to an Intranet. The discussion is based on a model which consists of the concepts Conception, Use, Technology, and Policy. Making the Philosophy of Technology common in organisations is connected to the empowerment of employees and is a guarantor, along with the influence of the VSM on the design, for the impact on and participation in the processes of an organisation. The next part deals with possible advantages of combining the cybernetic model, the Viable System Model, by Stafford Beer, and an Intranet. It is found that the VSM can support the design of Intranets according to essential functions such as Early Warning Systems connected to production units and levels that are to be made aware of undesired conditions in the organisation. Furthermore, functions for amplifying and attenuating information – both between parts of the organisation and between the organisation and the environment – are to be designed. Further examples of functions supporting the organisation, in order to make it viable, are given. The main contribution of the thesis is the identification of core functions in an Intranet as establishing functions for supervision (Early Warning Systems), attenuating and amplifying information between the organisation and the environment and between subparts in the organisation. Furthermore, the interface is to be designed so the underlying technology is “visible:” Where are the different parts of the Intranet located physically? Who delivers information to the different parts? Who uses the functions? Who is responsible? The transparency of the interface makes the philosophy of technology visible throughout the organisation; the concepts are the same, the actual use is the same as the intended use, and policy is active and well known and finally, the possibilities and the limitations with/inherent to an Intranet are known among the users.</p><p>Finally, examples of further research are given – both as regards the implementation of Intranets based on the VSM design and as regards making the interface transparent.</p>
70

Designing Intranets for Viability : Approaching Organizational Empowerment and Participation

Nyström, Christina Amcoff January 2006 (has links)
Intranets appeared in the mid-1990s and were perceived as the answer to the need for the integration of existing Information Systems into organisations. Despite the fact that there has been extensive research regarding implementation, development processes, policies standardisation vs. creativity and so forth, the potentiality of Intranets has not been fully exploited. Intranets offer many advantages in the form of working networks that support and enable empowered employees to participate in the development of the organisation, to enable the measurement of essential functions and to monitor undesired conditions and find suitable functions that support daily work. The research approach in this thesis has alternated between analysis empirical studies, and design. Current literature, research findings in the form of articles, etc., are analysed, an empirical study of five organisations is conducted and finally a design of possible functions is accomplished. In the analysis of the state-of-the-art, current research can be grouped into four topics partly overlapping each other; questions concerning informatics, organisation theory, knowledge management, and design. Urgent issues for further research are identified as mainly belonging to the topics informatics and organisation theory; management and strategy, empowerment, further development processes, use, and roles. Findings from a study of five Swedish organisations show a need for identifying the philosophy of technology in the organisations in order to make an organisation’s view of technology common throughout the organisation. Furthermore, functions supporting daily work are lacking to a high degree. Further lacks and demands are identified, as well as potential functions and new possibilities. In the next section, the Philosophy of Technology is related to an Intranet. The discussion is based on a model which consists of the concepts Conception, Use, Technology, and Policy. Making the Philosophy of Technology common in organisations is connected to the empowerment of employees and is a guarantor, along with the influence of the VSM on the design, for the impact on and participation in the processes of an organisation. The next part deals with possible advantages of combining the cybernetic model, the Viable System Model, by Stafford Beer, and an Intranet. It is found that the VSM can support the design of Intranets according to essential functions such as Early Warning Systems connected to production units and levels that are to be made aware of undesired conditions in the organisation. Furthermore, functions for amplifying and attenuating information – both between parts of the organisation and between the organisation and the environment – are to be designed. Further examples of functions supporting the organisation, in order to make it viable, are given. The main contribution of the thesis is the identification of core functions in an Intranet as establishing functions for supervision (Early Warning Systems), attenuating and amplifying information between the organisation and the environment and between subparts in the organisation. Furthermore, the interface is to be designed so the underlying technology is “visible:” Where are the different parts of the Intranet located physically? Who delivers information to the different parts? Who uses the functions? Who is responsible? The transparency of the interface makes the philosophy of technology visible throughout the organisation; the concepts are the same, the actual use is the same as the intended use, and policy is active and well known and finally, the possibilities and the limitations with/inherent to an Intranet are known among the users. Finally, examples of further research are given – both as regards the implementation of Intranets based on the VSM design and as regards making the interface transparent.

Page generated in 0.0357 seconds