| 1. |
- Aaboen, Lise, 1978
(författare)
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Incubators and new technology-based firms - A resource-based view of development
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- New technology-based firms (NTBFs) are based upon the exploitation of a new technology. This often means that there are few other than the founder who understands the technology, and in addition the firm often aims at serving a market in a new way or operating on a presently non-existent one. Therefore, it can be hard to determine the future potential of NTBFs, and this causes growth constraints on the firm. However, the NTBFs that do survive contribute to industrial and regional growth on a long-term perspective through, for example, knowledge spillovers as well as finding and developing product concepts. The incubator on the other hand can be seen as a provider or mediator accelerating the development of promising NTBFs. As a provider the incubator mobilizes resources and adjusts them to the needs of the particular NTBF. The mediator role can instead be seen when the incubator connects the NTBF to members of the incubators external network.The basis of the resource-based view is that a competitive advantage comes from the heterogeneity in terms of resources between firms. Imitability of valuable resources makes the competitive advantage sustainable. The newness of the NTBFs implies that they are in the process of trying to obtain or develop their resources. These resources include capabilities that determine how well the organization is able to perform a certain task. Furthermore, resources like funding, patenting, human resources and intangible resources are needed. Similarly, the incubator benefits from knowledge workers, funding and continuous improvements of the knowledge base in order to serve the NTBFs and maintain fruitful external relations. Consequently, this thesis has the purpose of exploring how the obtaining of resources link incubators and NTBFs. This exploration includes three papers in which the first two are devoted to the incubator, and the NTBFs respectively, in order to understand the resource needs of these two types of organizations. However, the third paper focuses on the links between the incubator and the NTBF in terms of providing links to external actors. Further, the exploration includes empirical findings from both qualitative and quantitative data that have been gathered within the Swedish incubator program during 1999 and 2005. The concluding discussion suggests that the human and knowledge resources of the incubator increase the external resources and the capabilities of the NTBFs. A successful NTBF in turn improves the human and knowledge resources of the incubator through knowledge sharing and an increased reputation. An increased survival rate of NTBFs will also positively affect the public funding of the incubator. It is in this way that a positive spiral is created where the resources of the incubator accumulate as more and more successful NTBFs are generated. Failing NTBFs will, on the other hand, also make it more difficult for the incubator to obtain and maintain resources. Seeing the connections between incubators and NTBFs in this way further emphasizes the element of path dependency in the development of these organizations. Subsequently, there is also a long-term aspect of the expected results on regions and industries from public investments made in them.
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| 2. |
- Aalipour, Mojgan
(författare)
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Human Factors Approach for Maintenance Improvement
- 2015
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this research work is to explore and describe human factors affectingmaintenance execution. To achieve the purpose of this study, the influencing factors have been identified using a literature survey. They have been categorized into four main groups namely organizational, workplace, job and individual factors. The Analytical Hierarchy Process (AHP) method is employed on data questionnaires to rank the priority of the factors. The interrelationships between these factors have been recognized by theInterpretive Structural Modelling (ISM) model. In the present case studies, MICMAC1analysis technique is also implemented for identifying the driving, dependent, linkage and autonomous factors. The data was collected through a questionnaire survey involving the participation of 16 and 25 maintenance staff and 10 mining experts in Swedish and Iranian mines, respectively. Within the study, it has been identified that the temperature, work layout, tools design and tools availability are the most important factors in both mines related to these categories. However, the significant factors in the organizational and individual categories are different in the selected mines. The effect of workplace factors on the maintainability of mining equipment is discussed and thereafter a methodology for maintainability management in the design and operation phases is developed. In the thirdcase study HEART2 is applied to estimate the probability of human error occurring duringmaintenance execution in an Iranian cable company. This research supports maintenance management to gain knowledge of human factors that affect maintenance execution. Further, this understanding could be useful in the development of strategies to improve the execution of maintenance.Keywords: Human Factors, Maintenance Management, Human Reliability, HumanPerformance, AHP, ISM, MICMAC, HEART
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| 3. |
- Aas, Gro Hanne
(författare)
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Kvinneforskningspolitiske (pr)øvelser
- 1999
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Målsettingen for licentiatuppsatsen er å analysere nordisk kvinneforsknings formuleringer av forskningspolitiske felter, problemstillinger og utfordringer, og gjennom kontakt og diskusjon bidra til samarbeid, diskusjoner og offentlighet om forskingspolitikk i kvinneforskning. Arbeidet har tatt utgangspunkt i relativt nytt materiale fra Danmark, Norge og Sverige. I kap. 1 presenteres prosjektet, problemstillinger og materiale. Kapitlene 2-6 består av innledninger og artikler holdt eller skrevet i løpet av de to senaste åren. Diskusjoner om kjønn og akademia står i fokus i kap. 2 - "Universities have politics". I kap. 3, artikkelen "Gamle og nye drømmer", diskuteres et kvinneforskningspolitiske intervensjonsprosjekt som blev utført for en del år tilbake, og det antydes noen nye omdreiningspunkter for et slikt arbeid. Enkelte perspektiver utdypes i kap. 4, "Kvinneforskningens samfunnskontrakt", hvor termen "kvinneperspektiv" som forskningspolitisk term granskas krtitiskt. De to siste kapitlene tar utgangspunkt i den norske forskningsmeldingen som kom våren 1999. Ut fra tre lesestrategier forsøkes det leses muligheter for kvinneforskningspolitiske strategier. Det ses også på innholdet i regjeringens forskningspolitiske verdidebatt, og det diskuteres mulige intervensjoner i denne ut fra feministiske vitenskaps- og teknologistudier.
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| 4. |
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| 5. |
- Abadikhah, Hossein, 1987
(författare)
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Dynamic higher order equations for structural elements
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The subject of this thesis is to derive and evaluate governing equations and corresponding boundary conditions for solid isotropic cylinders and isotropic micropolar rectangular plates. This is achieved by a systematic power series expansion approach, by either adopting a generalized Hamilton's principle or a direct approach.For the solid cylinders a power series expansion in the radial coordinate is adopted. Equations of motion together with consistent sets of end boundary conditions are derived in a systematic fashion up to arbitrary order using a generalized Hamilton's principle. Governing equations are obtained for longitudinal, torsional, and flexural modes. In the case of the isotropic micropolar plate a power series expansion of the displacements and micro-rotations are adopted in the thickness coordinate. Governing equations of motion, for extensional and flexural case, together with consistent sets of edge boundary conditions are derived in a systematic fashion up to arbitrary order with use of the direct approach.Both the governing equations for the solid cylinder and the micropolar plate are asymptotically correct to all studied orders. Numerical examples are presented for different sorts of problems, using exact theory, the present series expansion theories of different order, various classical theories and other newly developed approximate theories. These results cover dispersion curves, eigenfrequencies, various curves of cross sectional quantities such as displacements, stresses and micro-rotations, as well as fixed frequency motion due to prescribed end displacement or lateral distributed forces. The results illustrate that the present approach may render benchmark solutions provided higher order truncations are used, and act as engineering equations using low order truncation.
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| 6. |
- Abadikhah, Marie, 1992
(författare)
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Influence of electrode material and stochastic factors on the performance and microbial community assembly in microbial electrochemical systems
- 2022
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Microbial electrolysis cells (MECs) are systems with microbial communities in the form of biofilms on electrode surfaces. The electrogenic bacteria in the anode biofilm act as catalysts for the oxidization of organic compounds, leading to release of electrons, generation of electrical current, and production of hydrogen and methane at the cathode. In addition to production of energy carriers, MECs can be used for other applications as well; for example, as biosensors to monitor biochemical oxygen demand or toxicity. The performance of MECs is determined by both deterministic and stochastic factors influencing the microbial communities on the electrode surfaces, most of which as still poorly understood. In this thesis, the effects of electrode materials on microbial community assembly and MEC performance was investigated. Two experiments were carried out. In the first, three cathode materials (carbon nanoparticles, titanium, and steel) were compared. In the second, three anode materials (carbon cloth, graphene, and nickel) were compared. The cathode materials had no significant effect on the performance of the MECs, as opposed to the anode materials where carbon cloth MECs had the highest current density and the shortest lag time during startup. The differences seen in lag time of replicate systems at the start of the experiment indicated a stochastic initial attachment of the electrogenic bacteria on the anode. Different microbial communities develop in the biofilms on the anodes and cathodes. Electrogens from the Desulfobacterota phylum dominated the anode, while various hydrogenotrophic methanogens, e.g., Methanobacterium, were found to dominate on the cathodes. Diversity and null model analysis of the electrode communities highlighted stochasticity and not electrode material as the important factor in the community assembly. Network analysis showed that the cathode communities had fewer negative interactions between taxa in comparison to the anode. Since hydrogen gas generated at the cathode surface can diffuse through the biofilm, all microorganisms on the cathode have access to the substrate, reducing the need for competition between species. In contrast, electrogens require a short distance to the anode to be able to use it as electron acceptor. Limited space on the anode and competition between electrogens shaped the anode communities and explain the higher number of negative interactions observed. Based on the findings in this thesis, it is suggested that stochastic factors have more influence than electrode material on the anode community even though there is a selective pressure for electrogenic bacteria.
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| 7. |
- Abaravicius, Juozas
(författare)
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Load Management in Residential Buildings: Considering Techno-Economical and Environmental Aspects
- 2004
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Load problems in electricity markets occur both on the supply and demand side and can have technical, economic and even political causes. Commonly, such problems have been solved by expanding production and/or distribution capacity, importing electricity or by load management. Load management is a techno-economic measure for harmonizing the relations between supply and demand sides, optimizing power generation and transmission and increasing security of supply. Interest in load management differs depending on the perspective of the actors involved: from customer, utility, or producer to state policymaker. The problem of load demand and load management in residential sector is in this thesis approached from different perspectives, i.e. technical, economic, and environmental. The study does not go deep into detailed analyses of each perspective, but rather aims to establish and analyze the links between them. This trans-disciplinary approach is the key methodological moment used in the research work performed by the research group for load management in buildings at the Lund Institute of Technology. The key objective of this study is to analyze load demand variation and load management possibilities in residential sector, particularly detached and semi-detached houses, to experimentally test and analyze the conditions and potential of direct load management from customer and utility viewpoint. Techno-economic and environmental aspects are investigated. The study was performed in collaboration with one electric utility in Southern Sweden. Ten electric-heated houses were equipped with extra meters, enabling hourly load measurements for heating, hot water and total electricity use. Household heating and hot water systems were controlled by the utility using an existing remote reading and monitoring system. The residents noticed some of the control periods, although they didn’t express any larger discomfort. The experiments proved that direct load management might be a possible solution for the utility to solve their peak demand problems. Another solution, considered by the utility and analyzed in this study is a construction of diesel peak power plant. This alternative has negative environmental consequences compared to load management. The analysis of environmental aspects was extended to national level. To include an environmental perspective is a novel approach, since traditionally, load management evaluation is limited the economic and technical viewpoints. It identifies and discusses the possible environmental benefits of load management and evaluates their significance, primary focusing on CO2 emissions reduction. The results show the importance of considering the influence of site-specific or level-specific conditions on the environmental effects of load management. On the national level, load management measures can hardly provide significant environmental benefits, since hydropower is used as the demand following production source in Sweden. Emission reductions will rather be the result of energy efficiency measures, which will cut the load demand as well as the energy demand.
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| 8. |
- Abas, Riad Abdul
(författare)
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Property measurements towards understanding process phenomena
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main objective of this industrially important work was to gain an increasing understanding of the properties of materials such as CMSX-4 nickel base super alloy, mould powder used in continuous casting of steel and coke used in blast furnace, with special reference to the thermal diffusivities. The measurements were carried out in a wide temperature range, solid, liquid, glassy and crystalline states. For CMSX-4 alloy, the thermal conductivities were calculated from the experimental thermal diffusivities. Both the diffusivities and conductivities were found to increase with increasing temperature. Microscopic analysis showed the presence of intermetallic phases such as NiTi and NiTi2 below 1253 K. In this region, the mean free path of the phonons is likely to be limited by scattering against lattice defects. Between 1253 K and solidus temperature, these phases dissolved in the alloy adding to the impurities in the matrix, which, in turn, caused a decrease in the thermal diffusivity. This effect was confirmed by annealing the samples at 1573 K. The thermal diffusivities of the annealed samples measured at 1277, 1403 and 1531 K were found to be lower than the thermal diffusivities of non-annealed samples and the values did not show any noticeable change with time. It could be related to the attainment of equilibrium with the completion of the dissolution of γ and γ´ phases during the annealing process. Liquid CMSX-4 does not show any change of thermal diffusivity with temperature. It may be attributed to the decreasing the mean free path being shorter than characteristic distance between two neighbouring atoms. On the other hand thermal diffusivities of mould powder having glassy and crystalline states decrease with increasing temperature at lower temperature and are constant at higher temperature except for one glassy sample. Analogously, the thermal diffusivity measurements of mould powder did not show any significant change with temperature in liquid state. It is likely to be due to the silicate network being largely broken down. The thermal diffusivity is increased with increasing crystallisation degree of mould powder, which is expected from theoretical considerations. The coke sample, taken from deeper level of the blast furnace, is found to have larger thermal diffusivity. This could be correlated to the average crystallite size along the structural c-axis, Lc, which is indicative of the higher degree of graphitisation. This was also confirmed by XRD measurements of the different coke samples. The degree of graphitisation was found to increase with increasing temperature. Further, XRD measurements of coke samples taken from different levels in the shaft of the blast furnace show that the graphitisation of coke was instantaneous between room temperature and 1473 K.
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| 9. |
- Abbas, Muhammad
(författare)
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Requirements-Level Reuse Recommendation and Prioritization of Product Line Assets
- 2021
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Software systems often target a variety of different market segments. Targeting varying customer requirements requires a product-focused development process. Software Product Line (SPL) engineering is one possible approach based on reuse rationale to aid quick delivery of quality product variants at scale. SPLs reuse common features across derived products while still providing varying configuration options. The common features, in most cases, are realized by reusable assets. In practice, the assets are reused in a clone-and-own manner to reduce the upfront cost of systematic reuse. Besides, the assets are implemented in increments, and requirements prioritization also has to be done. In this context, the manual reuse analysis and prioritization process become impractical when the number of derived products grows. Besides, the manual reuse analysis process is time-consuming and heavily dependent on the experience of engineers.In this licentiate thesis, we study requirements-level reuse recommendation and prioritization for SPL assets in industrial settings. We first identify challenges and opportunities in SPLs where reuse is done in a clone-and-own manner. We then focus on one of the identified challenges: requirements-based SPL assets reuse and provide automated support for identifying reuse opportunities for SPL assets based on requirements. Finally, we provide automated support for requirements prioritization in the presence of dependencies resulting from reuse.
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| 10. |
- Abbas, Muhammad Tahir
(författare)
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Improving the Energy Efficiency of Cellular IoT Device
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cellular Internet of Things (CIoT) has emerged as a promising technology to support applications that generate infrequent data. One requirement on these applications, often battery-powered devices, is low energy consumption to enable extended battery life. Narrowband IoT (NB-IoT) is a promising technology for IoT due to its low power consumption, which is essential for devices that need to run on battery power for extended periods. However, the current battery life of NB-IoT devices is only a few years, which is insufficient for many applications. This thesis investigates the impact of energy-saving mechanisms standardized by 3GPP on battery life of NB-IoT devices. The main research objective is to classify and analyze existing energy-saving solutions for CIoT and examine their limitations, to study the impact of standardized energy-saving mechanisms on the battery life of NB-IoT devices, both in isolation and combined, and to provide guidelines on how to configure NB-IoT devices to reduce energy consumption efficiently. The research aims to provide a deeper understanding of the effect of energy-saving mechanisms and best practices to balance energy efficiency and performance of NB-IoT devices. Applying the proposed solutions makes it possible to achieve a battery life of 10~years or more for CIoT devices.
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