| 1. |
- Adamsson, Niklas, 1977-
(författare)
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Mechatronics engineering : New requirements on cross-functional integration
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Several industrial sectors experience an increased reliance on mechatronic systems as electronics and software are being embedded into the traditional mechanical systems of these industries. Important challenges within mechatronics engineering comes from management of multi-disciplinary development project teams and the highly complex scope of problems, which in turn require extensive coordination and integration, both in terms of technical and organisational matters. The concept of cross-functional integration in product development research has in previous research mainly addressed integration of the functions marketing, R&D, and manufacturing, and whereas the present thesis is delimited to include only the R&D organization and the functions and engineering disciplines within such an organization. The purpose with thesis has been to investigate mechatronics engineering in order to understand and explain how co-operation, integration, and knowledge sharing between engineering disciplines can be supported. This research has been realized by empirical studies in mechatronic development settings in engineering companies, but also by taking part in industrial and academic research projects that develop and study computer-aided mechatronics engineering. Findings presented in this thesis show that mechatronics is a matter of integration at three organizational levels where the most substantial needs are found to be at the team-level and the individual level. Furthermore, it is identified that to be able to succeed in mechatronics engineering, managers and engineers must look beyond disciplinary needs. Subsequently, both teamwork and competence management become key issues for management of mechatronics engineering. Finally, computer-supported and model-based development of mechatronics show great potential for successful integration of engineering disciplines, even though such technological aids are still rather immature and needs further research and development. A tentative analysis model of organizational integration for mechatronics engineering is also presented and discussed in this thesis. Based on the presented findings, it is concluded that companies incorporating electronics and software in their mechanical products must effectively manage software and electronics development of these embedded systems. Despite the focus on cross-functional integration in engineering companies, this thesis shows examples of inadequate integration of software and electronics engineering with mechanical integration in organisations dominated by the latter. Future research studies are needed to investigate the relation between factors influencing the need for organizational integration and potential integration mechanisms. To further understand mechatronics engineering it is important to look deeper into research issues such as changed conditions for the engineering profession implied by multidisciplinary settings, social systems supporting integration of disciplines, changed work conditions due to implementation of technological aids for model-based system development, relationship between product and organizational complexity, organizational designs supporting integration of engineering disciplines, and cross-disciplinary training of highly specialized engineers.
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| 2. |
- Ahmad, Noor Azlinda
(författare)
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Broadband and HF radiation from cloud flashes and narrow bipolar pulses
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Remote measurement of electric field generated by lightning has played a major role in understanding the lightning phenomenon. Even though other measurements such as optical, photographic, channel base current and thunder signatures have contributed in this regards, due to practical reasons remote measurements of electric field is considered as the most useful tool in lightning research. This thesis discussed about the remotely measured radiation field component of electric field generated by cloud flashes (ICs) and narrow bipolar pulses (NBPs). The associated HF radiation of these events at 3 MHz and 30 MHz were also discussed. To understand the initiation process of these discharges, a comparative study of the initial pulse of cloud flashes with the initial pulse of cloud to ground flashes was conducted. The result suggests that both discharges might have been initiated by similar physical process inside the thunderclouds. Comparing the features of initial pulse of cloud and ground flashes with that of pulses appeared in the later stages of cloud flashes suggests that the initiation process involved in both flashes are not very much differ from the initiation of cloud flashes at the later stage. The average spectral amplitudes of electric field for first 120 ms of cloud flashes showed f-1 frequency dependence within the interval of 100 kHz to about 2 MHz and does not follow the standard f-2 decrease (or even more) at high frequency region. It was suggested that small pulses which repeatedly appeared at the later stage of cloud flashes might have contribute to enhance the spectral amplitude at higher frequencies. Electric fields generated by Narrow Bipolar Pulses (NBPs), which are considered as one of the strongest source of HF radiation were measured in Malaysia in the tropic and their features were also studied. Result shows a good agreement with previously published observations of NBPs in other geographical regions. The pulse duration of NBPs is varied within 20 – 30μs with the normalized peak amplitude is of the order of 10 V/m, averagely 2– 3 times larger than the peak amplitude of ordinary return strokes. They were observed to emit intense burst of HF radiation at 30 MHz. Thorough analyses and observation of these pulses found previously unreported sharp, fine peaks embedded at the rising and decaying edge of the electric field change of NBPs. Therefore it was suggested that these fine peaks were most probably to be responsible for the intense HF radiation at 30 MHz.
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| 3. |
- Ahsan, Naveed, 1974-
(författare)
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Programmable and Tunable Circuits for Flexible RF Front Ends
- 2008
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Most of today’s microwave circuits are designed for specific function and specialneed. There is a growing trend to have flexible and reconfigurable circuits. Circuitsthat can be digitally programmed to achieve various functions based on specific needs. Realization of high frequency circuit blocks that can be dynamically reconfigured toachieve the desired performance seems to be challenging. However, with recentadvances in many areas of technology these demands can now be met.Two concepts have been investigated in this thesis. The initial part presents thefeasibility of a flexible and programmable circuit (PROMFA) that can be utilized formultifunctional systems operating at microwave frequencies. Design details andPROMFA implementation is presented. This concept is based on an array of genericcells, which consists of a matrix of analog building blocks that can be dynamicallyreconfigured. Either each matrix element can be programmed independently or severalelements can be programmed collectively to achieve a specific function. The PROMFA circuit can therefore realize more complex functions, such as filters oroscillators. Realization of a flexible RF circuit based on generic cells is a new concept.In order to validate the idea, a test chip has been fabricated in a 0.2μm GaAs process, ED02AH from OMMICTM. Simulated and measured results are presented along withsome key applications like implementation of a widely tunable band pass filter and anactive corporate feed network.The later part of the thesis covers the design and implementation of tunable andwideband highly linear LNAs that can be very useful for multistandard terminals suchas software defined radio (SDR). One of the key components in the design of a flexibleradio is low noise amplifier (LNA). Considering a multimode and multiband radiofront end, the LNA must provide adequate performance within a large frequency band.Optimization of LNA performance for a single frequency band is not suitable for thisapplication. There are two possible solutions for multiband and multimode radio frontends (a) Narrowband tunable LNAs (b) Wideband highly linear LNAs. A dual bandtunable LNA MMIC has been fabricated in 0.2μm GaAs process. A self tuningtechnique has also been proposed for the optimization of this LNA. This thesis alsopresents the design of a novel highly linear current mode LNA that can be used forwideband RF front ends for multistandard applications. Technology process for thiscircuit is 90nm CMOS.
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| 4. |
- Al Haji, Ghazwan
(författare)
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Towards a Road Safety Development Index (RSDI) : Development of an International Index to Measure Road Safety Performance
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aim. This study suggests a set of methodologies to combine different indicators of road safety into a single index. The RSDI is a simple and quick composite index, which may become a significant measurement in comparing, ranking and determining road safety levels in different countries and regions worldwide. Design. One particular concern in designing a Road Safety Development Index (RSDI) is to come up with a comprehensive set of exposure and risk indicators which includes as far as possible the main parameters in road safety related to human-vehicle-road and country patterns instead of considering few and isolated indicators such as accident rates. The RSDI gives a broad picture compared to the traditional models in road safety. Challenges. The differences in definitions, non-collection of data, no reliability of data and underreporting are problems for the construction of RSDI. In addition, the index should be as relevant as possible for different countries of the world, especially in developing countries.Empirical study. This study empirically compares the road safety situation and trends between ten Southeast Asian countries and Sweden for the period 1994- 2003. Methodologies. Eleven indicators are chosen in RSDI, which have been categorised in nine dimensions. Four main approaches (objective and subjective) are used to calculate RSDI and determine which one is the best. One approach uses equal weights for all indicators and countries, whereas the other approaches give different weights depending on the importance of indicators.Findings. The thesis examines the RSDI for the ten ASEAN countries and Sweden in 2003. The results from this study indicate a remarkable difference between ASEAN countries even at the same level of motorisation. Singapore and Brunei seem to have the best RSDI record among the ASEAN countries according to the indicators used, while Laos, Cambodia and Vietnam show lower RSDI records. Conclusions. The RSDI results seem very promising and worth testing further applications with bigger samples of countries and from different parts of the world.
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| 5. |
- Albinsson, Pär-Anders, 1975-
(författare)
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Interacting with command and control systems : Tools for operators and designers
- 2004
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Command and control is central in all distributed tactical operations such as rescue operations and military operations. It takes place in a complex system of humans and artefacts, striving to reach common goals. The command and control complexity springs from several sources, including dynamism, uncertainty, risk, time pressure, feedback delays and interdependencies. Stemming from this complexity, the thesis approaches two important and related problem areas in command and control research. On a general level, the thesis seeks to approach the problems facing the command and control operators and the problems facing the designers in the associated systems development process.We investigate the specific problem of operators losing sight of the overall perspective when working with large maps in geographical information systems with limited screen area. To approach this problem, we propose high-precision input techniques that reduce the need for zooming and panning in touch-screen systems, and informative unit representations that make better use of the screen area available. The results from an experimental study show that the proposed input techniques are as fast and accurate as state-of-the-art techniques without the need to resort to zooming. Furthermore, results from a prototype design show that the proposed unit representation reduces on-screen clutter and makes use of off-screen units to better exploit the valuable screen area.Developing command and control systems is a complex task with several pitfalls, including getting stuck in exhaustive analyses and overrated reliance on rational methods. In this thesis, we employ a design-oriented research framework that acknowledges creative and pragmatic ingredients to handle the pitfalls. Our approach adopts the method of reconstruction and exploration of mission histories from distributed tactical operations as a means for command and control analysis. To support explorative analysis of mission histories within our framework, we propose tools for communication analysis and tools for managing metadata such as reflections, questions, hypotheses and expert comments. By using these tools together with real data from live tactical operations, we show that they can manage large amounts of data, preserve contextual data, support navigation within data, make original data easily accessible, and strengthen the link between metadata and supporting raw data. Furthermore, we show that by using these tools, multiple analysts, experts, and researchers can exchange comments on both data and metadata in a collaborative and explorative investigation of a complex scenario.
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| 8. |
- Andersson, Ann-Christine
(författare)
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Practice-based Improvements in Healthcare
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A central problem for the healthcare sector today is how to manage change and improvements. In recent decades the county councils in Sweden have started various improvement initiatives and programs in order to improve their healthcare services. The improvement program of the Kalmar county council, which constitutes the empirical context for this thesis, is one of those initiatives.The purpose of this thesis is to contribute to a broader understanding of large-scale improvement program in a healthcare setting. This is done by analyzing practitioner’s improvement ideas, describing participants in the improvement projects, revising and testing a survey to measure the development of improvement ideas and describing the improvement program from a theoretical perspective. The theoretical change model used looks at change from two opposing directions in six dimensions; Goals, Leadership, Focus, Process, Reward system and Use of consultants.The aims of the county council improvement program are to become a learning organization, disseminate improvement methodologies and implement continuous quality improvements in the organization. All healthcare administrations and departments in the county council were invited to apply for funds to accomplish improvement projects. Another initiative invited staff teams to work with improvement ideas in a program with support from facilitators, using the breakthrough methodology. Now almost all ongoing developments, improvements, patient safety projects, manager and leader development initiatives are put together under the county council improvement program umbrella.In the appended papers both qualitative and quantitative research approach were used. The first study (paper I) analyzed which types of improvement projects practitioners are engaged in using qualitative content analysis. Five main categories were identified: Organizational Process; Evidence and Quality; Competence Development; Process Technology; and Proactive Patient Work. Most common was a focus on organizational changes and process, while least frequent was proactive patient work. Besides these areas of focus, almost all aimed to increase patient safety and increase effectiveness and availability.Paper II described the participants in two of the initiatives, the categorized improvement projects in paper I and the team members in the methodology guided improvement programs. Strong professions like physicians and nurses were well represented, but other staff groups were not as active. Managers were responsible for a majority of the projects. The gender perspective reflected the overall mix of employees in the county council.Paper III described a revision and test of a Minnesota Innovation Survey (MIS) that will be used to follow and measure how quality improvement ideas develop and improve over time. Descriptive statistics were presented. The respondents were satisfied with their work and what they had accomplished. The most common comment was about time, not having enough time to work with the improvement idea and the difficulty of finding time because of regular tasks. This was the first test of the revised survey and the high use of the answer alternative “Do not know” showed that the survey did not fit the context very well in its present version.Trying to connect the county council improvement program and the initiatives studied in papers I and II with the change model gave rise to some considerations. The county council improvement program has an effort to combine organizational changes and a culture that encourages continuous improvements. Top-down and bottom-up management approaches are used, through setting out strategies from above and at the same time encouraging practitioners to improve their day-to-day work. Whether this will be a successful way to implement and achieve a continuous improvement culture in the whole organization is one of the main issues remaining to find out in further studies.
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| 9. |
- Andersson, Henric, 1963-
(författare)
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Aircraft Systems Modeling : Model Based Systems Engineering in Avionics Design and Aircraft Simulation
- 2009
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aircraft developers like other development and manufacturing companies, are experiencing increasing complexity in their products and growing competition in the global market. One way to confront the challenges is to make the development process more efficient and to shorten time to market for new products/variants by using design and development methods based on models. Model Based Systems Engineering (MBSE) is introduced to, in a structured way, support engineers with aids and rules in order to engineer systems in a new way.In this thesis, model based strategies for aircraft and avionics development are studied. A background to avionics architectures and in particular Integrated Modular Avionics is described. The integrating discipline Systems Engineering, MBSE and applicable standards are also described. A survey on available and emerging modeling techniques and tools, such as Hosted Simulation, is presented and Modeling Domains are defined in order to analyze the engineering environment with all its vital parts to support an MBSE approach.Time and money may be saved by using modeling techniques that enable understanding of the engineering problem, state-of-the-art analysis and team communication, with preserved or increased quality and sense of control. Dynamic simulation is an activity increasingly used in aerospace, for several reasons; to prove the product concept, to validate stated requirements, and to verify the final implementation. Simulation is also used for end-user training, with specialized training simulators, but with the same underlying models. As models grow in complexity, and the set of simulation platforms is expanded, new needs for specification, model building and configuration support arise, which requires a modeling framework to be efficient.
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| 10. |
- Andersson, Lars, 1973-
(författare)
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Information sharing in mobile robot teams : deployment with uncertainty consideration
- 2004
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The work presented in this thesis deals with information sharing within mobile robot teams. Main focus is on information related to team positioning and localization. The goal of this research is to find models for how to best deploy a group of robots.The motion platforms covered are well adapted. although very important for the results. Motion models are crucial when calculating the dead reckoning of each platform. Results in the appended work show that the motion model has heavy impact on the possibility to affect the uncertainty of a robot team as new ground is deployed.The sensor models discussed may not necessarily be what is commonly used in the research field. Instead good approximations are used, that describe the main features of the sensor type. The focus is to present different sensor types and describe how the characteristics affect the uncertainty of the robot team, not to create new sensor models. A general model for sensors with polar measurement coordinates is derived. This can be used with different sensors with the same characteristics.A framework for sharing information within the robot team is derived. This is based on earlier work presented as "The Stochastic Map". However, the framework is tailored to suite the purpose of this work. Different estimation methods are also discussed, with main focus is on Kalman filtering techniques.The resulting part of this work present different ideas of what should be considered when deploying a group of robots. Results show how different dist ribution of sensors will affect the localization uncertainty of the group. It is also shown how different deployment formations affect the uncertainty within the team.
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