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  • 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.
1

Μελέτη και υλοποίηση δομών και αρχιτεκτονικών για ασύρματα βιομηχανικά δίκτυα υψηλών ταχυτήτων (>1Mbps)

Δρούζας, Παναγιώτης 01 August 2014 (has links)
Στην παρούσα εργασία θα μελετήσουμε αρχιτεκτονικές και δομές για ασύρματα βιομηχανικά δίκτυα υψηλών ταχυτήτων. Δηλαδή, πρωτόκολλα και μέσα μετάδοσης τα οποία θα είναι εφαρμόσιμα σε βιομηχανικά περιβάλλοντα, λόγω των εξειδικευμένων απαιτήσεων που έχουν αυτά τα περιβάλλοντα, και παράλληλα θα εξασφαλίζουν τις χρονικές αξιώσεις που αυτά οριοθετούν. / In this thesis we will investigate on wireless architectures for high speed industrial networks. Meaning, protocols and transmition mediums that are applicable in industrial environment mainly due to specific requirements that these environments impose and at the same time are able to fulfill the time requirements that exist in these environments.
2

Flexible company on rapidly changing market - Case study of HMS Industrial Networks

Pliszka, Sylwia, Olijarczyk, Slawomir, Iweins, François-Pascal January 2007 (has links)
<p>This paper is structured to answer the question why it is significant to be flexible on the market and also how to become a flexible company. To create cognitive perception of this issue, analyse of flexible company - an example of still prospering, a leader company HMS Industrial Network, is presented.</p>
3

Flexible company on rapidly changing market - Case study of HMS Industrial Networks

Pliszka, Sylwia, Olijarczyk, Slawomir, Iweins, François-Pascal January 2007 (has links)
This paper is structured to answer the question why it is significant to be flexible on the market and also how to become a flexible company. To create cognitive perception of this issue, analyse of flexible company - an example of still prospering, a leader company HMS Industrial Network, is presented.
4

Investigating Software-based Clock Synchronization for Industrial Networks

Gore, Rahul Nandkumar January 2021 (has links)
A rising level of industrialization and advances in Industry 4.0 have resulted in Industrial Internet of Things (IIoT) gaining immense significance in today’s industrial automation systems. IIoT promises to achieve improved productivity, reliability, and revenues by connecting time-constrained embedded systems to “the Internet”. New opportunities bring with them challenges, and in particular for industrial networks, massively interconnected IIoT devices communicating in real-time,  require synchronized operation of devices for the ordering of information collected throughout a  network. Thus,   a   time or clock synchronization service that aligns the devices’ clocks in the network to ensure accurate timestamping and orderly event executions, has gained great importance. Achieving adequate clock synchronization in the industrial domain is challenging due to heterogeneous communication networks and exposure to harsh environmental conditions bringing interference to the communication networks. The investigative study based on existing literature and the envisioned architecture of the future industrial automation system unveils that the key requirements for future industrial networks are to have a cost-effective, accurate, scalable, secured, easy to deploy and maintain clock synchronization solution. Today’s industrial automation systems employ clock synchronization solutions from a wide plethora of hardware and software based solutions. The most economical, highly scalable, maintainable software-based clock synchronization means are best candidates for the identified future requirements as their lack in accuracy compared to hardware solutions could be compensated by predictive software strategies.  Thus, the thesis’s overall goal is to enhance the accuracy of software-based clock synchronization in heterogeneous industrial networks using predictable software strategies. The first step towards developing an accurate clock synchronization for heterogeneous industrial networks with real-time requirements is to investigate communication parameters affecting time synchronization accuracy. Towards this goal, we investigated actual industrial network data for packet delay profiles and their impact on clock synchronization performance.  We further analyzed wired and wireless local area networks to identify key network parameters for clock synchronization and proposed an enhanced clock synchronization algorithm CoSiNeT for field IoT devices in industrial networks. CoSiNeT matches well with state-of-the-practice SNTP and state-of-the-art method SPoT in good network conditions in terms of accuracy and precision;  however,  it outperforms them in scenarios with degrading network conditions.
5

Drivers and Hindrances to Med-Tech Innovation : A device's guide to the Swedish healthcare galaxy

Wagrell, Sofia January 2017 (has links)
Today, the expectations on new medical technology solutions are substantial. On the one hand, healthcare policy expects new technologies both to improve the quality of people’s life and to reduce the burgeoning healthcare costs. On the other hand, innovation policy expects new med-tech solutions to stimulate economic growth, with large emphasis on the production of new solutions. However, despite the growing importance of med-tech innovations it is cumbersome to embed these innovative promising products into use in the Swedish healthcare sector. This thesis investigates med-tech innovation by following a microwave-based device in the treatment of the common disease BPH, Benign Prostatic Enlargement. This is an empirically based longitudinal study where the microwave device is used as a probe to capture a med-tech innovation journey. We follow the device through the efforts of technological and scientific development, through complex industrial production structures and foremost inits struggles to achieve widespread use in Swedish public healthcare. This study identifies a number of hindrances and drivers and, importantly, how they are interconnected in the innovation process. By applying the different settings of development, production and use of this device, a central finding is that the very same mechanisms can have contradicting effects in the different settings. Moreover, what functions as a trigger to innovation during development, can become later a hindrance to use. The study also shows that, whereas drivers prevail over hindrances in the development and production of med-tech solutions, hindrances clearly prevail in their use, which involves the provision of healthcare services. Not only has the use setting a generally weak financial support, but its organisational structures and regulations do also have a negative impact on the spread of new solutions in healthcare.
6

Análise de desempenho de redes de comunicação industrial em acionamentos de motores elétricos trifásicos / Performance analysis of industrial communication networks in electrical motors drives

Dias, André Luís 09 December 2014 (has links)
Este trabalho propõe analisar o desempenho de redes de comunicação industrial em aplicações de acionamentos de motores elétricos trifásicos. Compara-se o desempenho da tecnologia Profibus DP em relação à Profinet. O desempenho é verificado a partir de especificações técnicas de ambos protocolos e experimentos práticos para coleta de dados e análise dos seguintes indicadores de desempenho: tempo de ciclo, jitter e ocupação de largura de banda. Adicionalmente, é verificado o desempenho de uma aplicação de controle de posição, utilizando estes protocolos na malha de controle, através do tempo de acomodação do sistema. Conclusões mostram que a rede Profibus DPV0 é a mais rápida quando possui menos dispositivos, porém o Profinet RT consegue manter baixos valores de tempo de ciclo mesmo com grande quantidade de dispositivos e possui maior determinismo na topologia em barramento. No que diz respeito ao controle de posição estudado, as tecnologias apresentam desempenho similar para tempo de acomodação do sistema, porém o Profinet IRT foi o mais determinístico. / This work proposes a performance analysis of industrial communication networks in applications of electric AC motor drives. It compares the performance of Profibus DP technology in relation to Profinet. Performance is verified from technical specifications of both protocols and practical experiments for data collection and analysis of the following performance indicators: cycle time, jitter and bandwidth occupation. Additionally, the performance of a motion control application is verified, by using these protocols in the loop control, through the settling time of the system. Conclusions show that Profibus DPV0 is faster when there is less devices in the network, but Profinet RT manages to maintain low values of cycle time even with large number of devices and has higher determinism when installed in line topology. Regarding the motion control application studied, the technologies have similar settling time for the system performance, but the Profinet IRT was more deterministic.
7

Análise de desempenho de redes de comunicação industrial em acionamentos de motores elétricos trifásicos / Performance analysis of industrial communication networks in electrical motors drives

André Luís Dias 09 December 2014 (has links)
Este trabalho propõe analisar o desempenho de redes de comunicação industrial em aplicações de acionamentos de motores elétricos trifásicos. Compara-se o desempenho da tecnologia Profibus DP em relação à Profinet. O desempenho é verificado a partir de especificações técnicas de ambos protocolos e experimentos práticos para coleta de dados e análise dos seguintes indicadores de desempenho: tempo de ciclo, jitter e ocupação de largura de banda. Adicionalmente, é verificado o desempenho de uma aplicação de controle de posição, utilizando estes protocolos na malha de controle, através do tempo de acomodação do sistema. Conclusões mostram que a rede Profibus DPV0 é a mais rápida quando possui menos dispositivos, porém o Profinet RT consegue manter baixos valores de tempo de ciclo mesmo com grande quantidade de dispositivos e possui maior determinismo na topologia em barramento. No que diz respeito ao controle de posição estudado, as tecnologias apresentam desempenho similar para tempo de acomodação do sistema, porém o Profinet IRT foi o mais determinístico. / This work proposes a performance analysis of industrial communication networks in applications of electric AC motor drives. It compares the performance of Profibus DP technology in relation to Profinet. Performance is verified from technical specifications of both protocols and practical experiments for data collection and analysis of the following performance indicators: cycle time, jitter and bandwidth occupation. Additionally, the performance of a motion control application is verified, by using these protocols in the loop control, through the settling time of the system. Conclusions show that Profibus DPV0 is faster when there is less devices in the network, but Profinet RT manages to maintain low values of cycle time even with large number of devices and has higher determinism when installed in line topology. Regarding the motion control application studied, the technologies have similar settling time for the system performance, but the Profinet IRT was more deterministic.
8

From Organisational Behaviour to Industrial Network Evolutions: Stimulating Sustainable Development of Bioenergy Networks in Emerging Economies

Kempener, Rudolf T. M January 2008 (has links)
Doctor of Philosophy (PhD) / The aim of this thesis is to understand what drives the evolution of industrial networks and how such understanding can be used to stimulate sustainable development. A complex adaptive systems perspective has been adopted to analyse the complex interaction between organisational behaviour and industrial network evolution. This analysis has formed the basis for the development of a modelling approach that allows for quantitative exploration of how different organisational perceptions about current and future uncertainty affect their behaviour and therefore the network evolution. This analysis results in a set of potential evolutionary pathways for an industrial network and their associated performance in terms of sustainable development. Subsequently, this modelling approach has been used to explore the consequences of interventions in the network evolution and to identify robust interventions for stimulating sustainable development of industrial networks. The analysis, modelling approach and development of interventions has been developed in the context of a bioenergy network in the region of KwaZulu-Natal in South Africa. Industrial networks are an important aspect of today’s life and provide many goods and services to households and individuals all over the world. They consist of a large number of autonomous organisations, where some organisations contribute by transforming or transacting natural resources, such as oil, agricultural products or water, while other organisations contribute to networks by providing information or setting regulation or subsidies (local or national governments) or by influencing decision making processes of other organisations in networks (advocacy groups). Throughout the process from natural resource to product or service, industrial networks have important economic, environmental and social impacts on the socio-economic and biophysical systems in which they operate. The sum of complex interactions between organisations affects the rate in which natural resources are used, environmental impacts associated with transformation and transaction of resources and social impacts on local communities, regions or countries as a whole. The aim of this thesis is to understand how industrial networks evolve and how they can be stimulated towards sustainable development. The first question that has been addressed in this thesis is how to understand the complex interaction between organisational behaviour and industrial network evolution. Organisational behaviour is affected by many functional and implicit characteristics within the environment in which the organisation operates, while simultaneously the environment is a function of non-linear relationships between individual organisational actions and their consequences for both the function and structure of the network. This thesis has identified four different characteristics of industrial networks that affect organisational behaviour: 1) Functional characteristics 2) Implicit behavioural characteristics 3) Implicit relational characteristics 4) Implicit network characteristics. Functional characteristics are those characteristics that are formally recognised by all organisations within an industrial network and which affect their position within the network. Examples of functional characteristics are the price and quantity of resources available, the location and distance of organisations within a network, infrastructure availability or regulation. Implicit characteristics, on the other hand, are those characteristics that impact the decision making process of organisations, but which are not formally part of the network. From an organisational perspective, implicit characteristics are the rules, heuristics, norms and values that an organisation uses to determine its objectives, position and potential actions. Implicit relational characteristics, most importantly trust and loyalty, affect an organisations choice between potential partners and implicit network characteristics are those social norms and values that emerge through social embeddedness. Collectively, these functional and implicit characteristics and their interactions determine the outcome of organisational decisions and therefore the direction of the industrial network evolution. The complex interaction between these large numbers of characteristics requires quantitative models to explore how different network characteristics and different interactions result in different network evolutions. This thesis has developed an agent-based simulation model to explore industrial network evolutions. To represent the multi-scale complexity of industrial networks, the model consists of four scales. Each scale represents different processes that connect the functional and implicit characteristics of an industrial network to each other. The two basic scales represent the strategic actions of the organisations on the one hand and the industrial network function and structure on the other. The third scale represents the processes that take place within the mental models of organisations describing how they make sense of their environment and inform their strategic decision making process. The fourth scale represents the social embeddedness of organisations and how social processes create and destroy social institutions. The model has been developed such that it allows for exploring how changes in different network characteristics or processes affect the evolution of the network as a whole. The second question that has been addressed in this thesis is how to evaluate sustainable development of different evolutionary pathways of industrial networks. First of all, a systems approach has been adopted to explore the consequences of an industrial network to the larger socio-economic and biophysical system in which the network operates. Subsequently, a set of structural indicators has been proposed to evaluate the dynamic performance of industrial networks. These four structural indicators reflect the efficiency, effectiveness, resilience and adaptiveness of industrial networks. Efficiency and effectiveness relate to the operational features by which industrial networks provides a particular contribution to society. Resilience and adaptiveness relate to the system’s capacity to maintain or adapt its contribution to society while under stress of temporary shocks or permanent shifts, respectively. Finally, different multi-criteria decision analysis (MCDA) tools have been applied to provide a holistic evaluation of sustainable development of industrial networks. The third important question that is addressed in this thesis is how to systematically explore the potential evolutionary pathways of an industrial network, which has led to the development of agent-based scenario analysis. Agent-based scenario analysis systematically explores how industrial network evolutions might evolve depending on the perceptions of organisations towards the inherent uncertainty associated with strategic decision making in networks. The agent-based scenario analysis consists of two steps. Firstly, analysts develop a set of coherent context scenarios, which represents their view on the context in which an industrial network will operate within the future. For a bioenergy network, for example, this step results in a set of scenarios that each represent a coherent future of the socio-economic system in which the network might evolve. The second step is the development of a set of ‘agent scenarios’. Each agent-based scenario is based on a different ‘mental model’ employed by organisations within the network about how to deal with the inherent ambiguity of the future. The organisational perspective towards uncertainty is of major importance for the evolution of industrial networks, because it determines the innovative behaviour of organisations, the structure of the network and the direction in which the network evolves. One the one hand, organisations can ignore future ambiguity and base their actions on the environment that they can observe in their present state. On the other extreme, organisations can adopt a view that the future is inherently uncertain and in which they view social norms and values more important than functional characteristics to make sense of their environment. The mental models are differentiated according to two dimensions: 1) different mental representation of the world and 2) different cognitive processes that can be employed to inform strategic actions. Along these dimensions, different processes can be employed to make sense of the environment and to inform decision making. The thesis has shown that by systematically exploring the different perceptions possible, an adequate understanding of the different evolutionary pathways can be gained to inform the evaluation and development of interventions to stimulate sustainable development. The final part of this thesis has applied the analysis and methodology developed throughout this thesis to a bioenergy network in the province of Kwazulu-Natal in South Africa. The bioenergy network consists of a set of existing sugar mills with large quantities of bagasse, a biomass waste product, available. Bagasse is currently burned inefficiently to produce steam for the sugar mills, but can potentially be used for the production of green electricity, biodiesel, bioethanol or gelfuel. All of these products have important consequences for the region in terms of associated reductions in CO2 emissions, electrification of and/or energy provision for rural households and local economic development of the region. This thesis has modelled strategic decisions of the sugar mills, the existing electricity generator, potential independent energy producers, local and national governments and how their actions and interactions can lead to different evolutionary pathways of the bioenergy network. The agent-based scenario analysis has been used to explore how different perceptions of organisations can lead to different network evolutions. Finally, the model has been used to explore the consequences of two categories of interventions on stimulating sustainable development. The conclusions are that both categories of interventions, financial interventions by national government and the introduction of multi-criteria decision analysis (MCDA) tools to aid strategic decision making, can have both positive and negative effects on the network evolutions, depending on what ‘mental models’ are employed by organisations. Furthermore, there is no single intervention that outperforms the others in terms of stimulating both functional and structural features of sustainable development. The final conclusion is that instead of focusing on individual or collective targets, emphasis should be placed on the development of interventions that focus on evolutionary aspects of industrial networks rather than functional performance criteria. This thesis has also highlighted interesting research questions for future investigation. The methodology developed in this thesis is applied to a single case study, but there are still many questions concerning how different industrial networks might benefit from different organisational perceptions towards uncertainty. Furthermore, the role between the mental models and sustainable development requires further investigation, especially in the light of globalisation and the interconnectiveness of industrial networks in different countries and continents. Finally, this methodology has provided a platform for investigating how new technologies might be developed that anticipate needs of future generations. This thesis has provided a first and important step in developing a methodology that addresses the complex issues associated with sustainable development, benefiting both academics and practitioners that aim to stimulate sustainable development.
9

Industrial change towards environmental sustainability : the case of chloroflourocarbons

Sweet, Susanne January 2000 (has links)
This thesis aims at providing an insight into one of the most influential ecological change efforts of our time, culminating with the banning of the use of chloroflourocarbons, CFCs, conceded as being linked to one of the most severe threats to our ecosystem, the depletion of the earth's ozone layer. This change effort, extending over a quarter century, is analyzed, drawing on the responses of three unrelated industries directly affected by the ban. As this thesis exposes, industry can play something of a dual role, on the one hand as a substantial contributor to ecological problems and on the other, as a promising source of solutions to such problems. A greater understanding of forces that impede or propel industrial change toward sustainable practices will enhance the capacities of both industrial actors and policymakers to design policies, industrial processes, and products aimed at promoting environmental sustainability. The change efforts carried out in three different, real and expanding industrial contexts, namely, refrigerator manufacture, circuit board assembly and furniture foam processing, are addressed. It is hoped that this thesis offers researchers, managers, policy makers, environmentalists and others directly interested the insight it sets out to provide into the workings of change towards sustainability in larger industrial systems. / <p>Diss. Stockholm : Handelshögskolan, 2000</p>
10

Jordens kretslopp : lantbruket, staden och den kemiska vetenskapen 1840-1910

Mårald, Erland January 2000 (has links)
This study of the institutionalization and professionalization of agricultural chemistry during the second half of the nineteenth century analyses the relationship between chemical theories and social issues, ideas and experience of recycling, the development of fertilizers, and industrialization of agriculture. The study mainly takes a history of science and environmental history perspective with focus on the Swedish case. It does, however, address the international context offering a historical perspective of issues such as the relationship between population and natural resources, the sustainability of society and connections between science, technology and nature. The center of this study consists of an analysis of the work of the following agricultural chemists employed by the Swedish Royal Agricultural Society, enumerated in chronological order: Alexander Müller, Carl Erik Bergstrand, and Lars Fredrik Nilson. Other actors, such as agriculturists, administrators and politicians, were also important in the formation of agricultural chemistry in Sweden. Changes of aims and agricultural chemical ideals during the period of study reflect changes in society and shifting ideologies. During the second half of the nineteenth century a national "agricultural scientific infrastructure" was erected with experimental stations, agricultural schools, local experimental fields and agrarian experts. This network constituted a basis for agricultural science in society and functioned as an important channel for the modernization of agriculture and society. With agricultural chemistry as an empirical point of departure, this thesis also analyzes the transformations of agriculture with the establishment of cultural, economical and physical links between agriculture and the surrounding world. Theories about chemical cycles promoted recycling of nutrition and other materials between the city and the countryside, thereby connecting agriculture to the city. The development of new mineral and nitrogenous fertilizers gradually involved an increased use of inorganic raw materials and energy to manufacture nutrition. This process resulted in the intertwining of agriculture, science, mining, industry and energy production and the creation of an agro- industrial network, which was crucial for the development of agriculture during the twentieth century. In this context, agricultural science legitimized the development toward resource intensive farming methods. / digitalisering@umu

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