| 1. |
- Larsson, Stefan
(författare)
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Law and Spatial Planning. Socio-legal Perspectives on the Development of Wind Power and 3G Mobile Infrastructures in Sweden
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This PhD thesis in Spatial Planning argues for the importance of understanding the approaches to knowledge and rationalities embedded in spatially relevant decision-making. It emphasises the significance of seeing law as an empirical object of study for planning and environmental management. The Swedish development of wind power and 3G mobile infrastructures are used as cases to study these issues of principal interest. It is a compilation thesis consisting of a comprehensive introductory framework and five articles or chapters that have also been published elsewhere. The study is based on three main perspectives: Level of decision-making, legitimacy of different forms of knowledge involved in the process, and the sociolegal tension between formal law and its practical consequences. The thesis deals with problems stemming from the multi-level tensions in the planning and implementation that exist between the national, the regional and the local authorities. The legal context is analysed from the sociolegal perspective, in particular how the juridification of siting and permit conflicts determines what type of knowledge that can legitimately affect the decision-making and thereby set conditions for public participation. Finally, the thesis elaborates on the largely counterproductive results of the strong emphasis on “efficiency” in the revision of planning and permit processes for wind power and 3G-infrastructure, and what can be learnt from the experiences of the attempts at increasing efficiency. A combination of methods has been employed in the studies, and the data comes from a range of sources such as a large set of mast building permits, a sample of wind permit cases, as well as appealed permit cases. In addition, interviews have been conducted with judges from relevant courts, including regional handling officers who assess wind turbine applications. Legal documents such as preparatory work and licence conditions have also been analysed. The results show that there is a legal-rhetorical adaptation to the expert-based decision-making in court when permits are appealed. Further, the administrative levels interact poorly in the overall implementation. The national decisions, irrespective of the normative viewpoint of who should control the landscape planning, could be better informed of the preconditions at a local level that factually define the outcome of the implementation. The author, Stefan Larsson, holds a PhD in Sociology of Law, an LLM and is a sociolegal researcher who generally studies issues in the intersection of conceptual, sociolegal and technological change. The thesis has been supervised by Professor Lars Emmelin, The Swedish School of Planning, BTH, and co-supervised by Professor Karsten Åström, the Department of Sociology of Law, Lund University. The thesis is the result of research within the programme Tools for environmental assessment in strategic decision-making, MiSt, funded by The Swedish Environmental Protection Agency and the Centre for Work, Technology and Social Change at Lund University.
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| 2. |
- Sandhu, Momin Jamil
(författare)
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On Sequence Design for Integrated Radar and Communication Systems
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The motivation of having a joint radar and communication system on a single hardware is driven by space, military, and commercial applications. However, designing sequences that can simultaneously support radar and communication functionalities is one of the major hurdles in the practical implementation of these systems. In order to facilitate a simultaneous use of sequences for both radar and communication systems, a flexible sequence design is needed.The objective of this dissertation is to address the sequence design problem for integrated radar and communication systems. The sequence design for these systems requires a trade-off between different performance measures, such as correlation characteristics, integrated sidelobe ratio, peak-to-sidelobe ratio and ambiguity function. The problem of finding a trade-off between various performance measures is solved by employing meta-heuristic algorithms.This dissertation is divided into an introduction and three research parts based on peer-reviewed publications. The introduction provides background on binary and polyphase sequences, their use in radar and communication systems, sequence design requirements for integrated radar and communication systems, and application of meta-heuristic optimization algorithms to find optimal sets of sequences for these systems.In Part I-A, the performance of conventional polyphase pulse compression sequences is compared with Oppermann sequences. In Part I-B, weighted pulse trains with the elements of Oppermann sequences serving as complex-valued weights are utilized for the design of integrated radar and communication systems. In Part I-C, an analytical expression for the cross-ambiguity function of weighted pulse trains with Oppermann sequences is derived. Several properties of the related auto-ambiguity and cross-ambiguity functions are derived in Part I-D. In Part II, the potential of meta-heuristic algorithms for finding optimal parameter values of Oppermann sequences for radar, communications, and integrated radar and communication systems is studied. In Part III-A, a meta-heuristic algorithm mimicking the breeding behavior of Cuckoos is used to locate more than one solution for multimodal problems. Further, the performance of this algorithm is evaluated in additive white Gaussian noise (AWGN). It is shown that the Cuckoo search algorithm can successfully locate multiple solutions in both non-noise and AWGN with relatively high degree of accuracy. In Part III-B, the cross-ambiguity function synthesization problem is addressed. A meta-heuristic algorithm based on echolocation of bats is used to design a pair of sequences to minimize the integrated square error between the desired cross-ambiguity function and a synthesized cross-ambiguity function.
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| 3. |
- Hagelbäck, Johan, 1977-
(författare)
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Multi-Agent Potential Field based Architectures for Real-Time Strategy Game Bots
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Real-Time Strategy (RTS) is a sub-genre of strategy games which is running in real-time, typically in a war setting. The player uses workers to gather resources, which in turn are used for creating new buildings, training combat units, build upgrades and do research. The game is won when all buildings of the opponent(s) have been destroyed. The numerous tasks that need to be handled in real-time can be very demanding for a player. Computer players (bots) for RTS games face the same challenges, and also have to navigate units in highly dynamic game worlds and deal with other low-level tasks such as attacking enemy units within fire range.This thesis is a compilation grouped into three parts. The first part deals with navigation in dynamic game worlds which can be a complex and resource demanding task. Typically it is solved by using pathfinding algorithms. We investigate an alternative approach based on Artificial Potential Fields and show how an APF based navigation system can be used without any need of pathfinding algorithms.In RTS games players usually have a limited visibility of the game world, known as Fog of War. Bots on the other hand often have complete visibility to aid the AI in making better decisions. We show that a Multi-Agent PF based bot with limited visibility can match and even surpass bots with complete visibility in some RTS scenarios. We also show how the bot can be extended and used in a full RTS scenario with base building and unit construction.In the next section we propose a flexible and expandable RTS game architecture that can be modified at several levels of abstraction to test different techniques and ideas. The proposed architecture is implemented in the famous RTS game StarCraft, and we show how the high-level architecture goals of flexibility and expandability can be achieved.In the last section we present two studies related to gameplay experience in RTS games. In games players usually have to select a static difficulty level when playing against computer oppo- nents. In the first study we use a bot that during runtime can adapt the difficulty level depending on the skills of the opponent, and study how it affects the perceived enjoyment and variation in playing against the bot.To create bots that are interesting and challenging for human players a goal is often to create bots that play more human-like. In the second study we asked participants to watch replays of recorded RTS games between bots and human players. The participants were asked to guess and motivate if a player was controlled by a human or a bot. This information was then used to identify human-like and bot-like characteristics for RTS game players.
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| 4. |
- Petrakou, Alexandra
(författare)
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Design for Places of Collaboration
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis reports a research effort that comprises six papers and a cover paper. In essence, the thesis contributes to the understanding of collaborative settings by introducing the perspective of ‘places of collaboration’. This perspective is particularly important when designing computer-based technologies that support collaborative settings. The starting point and overall research aim is to understand people’s efforts to configure their current context for the purposes of collaboration. The cover paper of the thesis comprises a theoretical reflection and examination of four collaborative settings. The settings have been studied in situ through ethnographic inquiry and the results are reported in the six papers enclosed in the thesis. In my theoretical reflection, the concepts of ‘place’, ‘space’ and ‘boundary objects’ are central. The studies revealed that people’s efforts to configure the current context create and reflect a ‘place of collaboration’. In other words, the effort to configure the context results in a practice characterized by an understanding of how to cooperate; a collaborative practice that constitutes a ‘place of collaboration’. During this configuration, the space and the use of materiality in this space are important parts in the creation of a place of collaboration. In addition, people configure collaborative contexts of intersecting practices by creating boundary objects. Boundary objects serve as mediators in a place-making process for the integration of places into a ‘place of collaboration’ for several practices. What is more, the dynamics of a place of collaboration may affect changes in existing modes of working and in computer-based tools that have been introduced into the workplace. The people and practices that constitute the place will in turn re-configure the place of collaboration, including the space and objects available due to the new circumstances. People’s configuration of their current context reveals crucial aspects about the place of collaboration that must be considered also when designing to support this setting. However, this configuration may not necessarily equal efficiency and effectiveness, as evaluated by actors external to this context. The conclusion of this thesis is that future research and design should consider how to support people in their own effort to configure their collaborative context.
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| 5. |
- Afzal, Wasif
(författare)
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Search-Based Prediction of Software Quality : Evaluations and Comparisons
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Software verification and validation (V&V) activities are critical for achieving software quality; however, these activities also constitute a large part of the costs when developing software. Therefore efficient and effective software V&V activities are both a priority and a necessity considering the pressure to decrease time-to-market and the intense competition faced by many, if not all, companies today. It is then perhaps not unexpected that decisions that affects software quality, e.g., how to allocate testing resources, develop testing schedules and to decide when to stop testing, needs to be as stable and accurate as possible. The objective of this thesis is to investigate how search-based techniques can support decision-making and help control variation in software V&V activities, thereby indirectly improving software quality. Several themes in providing this support are investigated: predicting reliability of future software versions based on fault history; fault prediction to improve test phase efficiency; assignment of resources to fixing faults; and distinguishing fault-prone software modules from non-faulty ones. A common element in these investigations is the use of search-based techniques, often also called metaheuristic techniques, for supporting the V&V decision-making processes. Search-based techniques are promising since, as many problems in real world, software V&V can be formulated as optimization problems where near optimal solutions are often good enough. Moreover, these techniques are general optimization solutions that can potentially be applied across a larger variety of decision-making situations than other existing alternatives. Apart from presenting the current state of the art, in the form of a systematic literature review, and doing comparative evaluations of a variety of metaheuristic techniques on large-scale projects (both industrial and open-source), this thesis also presents methodological investigations using search-based techniques that are relevant to the task of software quality measurement and prediction. The results of applying search-based techniques in large-scale projects, while investigating a variety of research themes, show that they consistently give competitive results in comparison with existing techniques. Based on the research findings, we conclude that search-based techniques are viable techniques to use in supporting the decision-making processes within software V&V activities. The accuracy and consistency of these techniques make them important tools when developing future decision-support for effective management of software V&V activities.
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| 6. |
- Ahmadi Mehri, Vida
(författare)
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Towards Automated Context-aware Vulnerability Risk Management
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The information security landscape continually evolves with increasing publicly known vulnerabilities (e.g., 25064 new vulnerabilities in 2022). Vulnerabilities play a prominent role in all types of security related attacks, including ransomware and data breaches. Vulnerability Risk Management (VRM) is an essential cyber defense mechanism to eliminate or reduce attack surfaces in information technology. VRM is a continuous procedure of identification, classification, evaluation, and remediation of vulnerabilities. The traditional VRM procedure is time-consuming as classification, evaluation, and remediation require skills and knowledge of specific computer systems, software, network, and security policies. Activities requiring human input slow down the VRM process, increasing the risk of exploiting a vulnerability.The thesis introduces the Automated Context-aware Vulnerability Risk Management (ACVRM) methodology to improve VRM procedures by automating the entire VRM cycle and reducing the procedure time and experts' intervention. ACVRM focuses on the challenging stages (i.e., classification, evaluation, and remediation) of VRM to support security experts in promptly prioritizing and patching the vulnerabilities. ACVRM concept is designed and implemented in a test environment for proof of concept. The efficiency of patch prioritization by ACVRM compared against a commercial vulnerability management tool (i.e., Rudder). ACVRM prioritized the vulnerability based on the patch score (i.e., the numeric representation of the vulnerability characteristic and the risk), the historical data, and dependencies. The experiments indicate that ACVRM could rank the vulnerabilities in the organization's context by weighting the criteria used in patch score calculation. The automated patch deployment is implemented with three use cases to investigate the impact of learning from historical events and dependencies on the success rate of the patch and human intervention. Our finding shows that ACVRM reduced the need for human actions, increased the ratio of successfully patched vulnerabilities, and decreased the cycle time of VRM process.
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| 7. |
- Al-Saedi, Ahmed Abbas Mohsin, 1980-
(författare)
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Resource-Aware and Personalized Federated Learning via Clustering Analysis
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Today’s advancement in Artificial Intelligence (AI) enables training Machine Learning (ML) models on the daily-produced data by connected edge devices. To make the most of the data stored on the device, conventional ML approaches require gathering all individual data sets and transferring them to a central location to train a common model. However, centralizing data incurs significant costs related to communication, network resource utilization, high volume of traffic, and privacy issues. To address the aforementioned challenges, Federated Learning (FL) is employed as a novel approach to train a shared model on decentralized edge devices while preserving privacy. Despite the significant potential of FL, it still requires considerable resources such as time, computational power, energy, and bandwidth availability. More importantly, the computational capabilities of the training devices may vary over time. Furthermore, the devices involved in the training process of FL may have distinct training datasets that differ in terms of their size and distribution. As a result of this, the convergence of the FL models may become unstable and slow. These differences can influence the FL process and ultimately lead to suboptimal model performance within a heterogeneous federated network.In this thesis, we have tackled several of the aforementioned challenges. Initially, a FL algorithm is proposed that utilizes cluster analysis to address the problem of communication overhead. This issue poses a major bottleneck in FL, particularly for complex models, large-scale applications, and frequent updates. The next research conducted in this thesis involved extending the previous study to include wireless networks (WNs). In WSNs, achieving energy-efficient transmission is a significant challenge due to their limited resources. This has motivated us to continue with a comprehensive overview and classification of the latest advancements in context-aware edge-based AI models, with a specific emphasis on sensor networks. The review has also investigated the associated challenges and motivations for adopting AI techniques, along with an evaluation of current areas of research that need further investigation. To optimize the aggregation of the FL model and alleviate communication expenses, the initial study addressing communication overhead is extended to include a FL-based cluster optimization approach. Furthermore, to reduce the detrimental effect caused by data heterogeneity among edge devices on FL, a new study of group-personalized FL models has been conducted. Finally, taking inspiration from the previously mentioned FL models, techniques for assessing clients' contribution by monitoring and evaluating their behavior during training are proposed. In comparison with the most existing contribution evaluation solutions, the proposed techniques do not require significant computational resources.The FL algorithms presented in this thesis are assessed on a range of real-world datasets. The extensive experiments demonstrated that the proposed FL techniques are effective and robust. These techniques improve communication efficiency, resource utilization, model convergence speed, and aggregation efficiency, and also reduce data heterogeneity when compared to other state-of-the-art methods.
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| 8. |
- Andersén, Jimmie, 1981-
(författare)
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Ett politiskt bygge : - översiktsplaneringens innehållsmässiga utveckling
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Debate often describes the evolution of spatial planning as a process of neo-liberalisation. However, this evolution has not been studied from the perspective of planning in general in Sweden. Whether comprehensive planning is also undergoing neo-liberalisation is considered here based on these overarching research questions: - To what extent has spatial planning undergone neo-liberalisation?- How can the evolution of comprehensive planning be understood as a neo-liberalisation process?Answering these questions requires an understanding of the content characterising this planning, and of what a neo-liberalisation process entails. To achieve such an understanding, this dissertation examines how planning in general can be understood as both a political control system and a market-based land use regime.The discourse of comprehensive planning was studied by analysing 17 comprehensive plans adopted in five municipalities over the 1989–2014 period.Generally, these plans follow a few main evolutionary paths. Municipal comprehensive planning has transitioned from being instrumental, encountering few problems, to becoming increasingly abstract and all-encompassing. Comprehensive planning increasingly concerns how growth is to be achieved locally. This change is occurring in both form and content. Change in form refers to the fact that comprehensive planning has been encompassing more and more subject areas over time, whereas change in content refers to the increasingly market-based content of such planning.The research question regarding the extent to which spatial planning is undergoing neo-liberalisation is answered by the obvious trend towards neo-liberalisation. This trend is not pervasive, as countervailing tendencies are also present. Spatial planning is thus becoming internally contradictory, with earlier values persisting, albeit often in interaction with new ones.The question of how comprehensive planning can be understood as a neo-liberalisation process has a three-part answer:- As content in comprehensive plans, neo-liberalisation can be understood as a focus on market rationality. - As form in comprehensive plans, neo-liberalisation can be understood as policy production with content that assumes an ever more neo-liberal orientation. Comprehensive planning during the studied period has come to include more and more municipal areas of activity.- From a neo-liberal perspective, neo-liberalisation is understood as economic utility maximisation.Planning is becoming increasingly neo-liberalised, but not neo-liberal. That this has occurred as a result of increasingly comprehensive policy formulations is somewhat surprising. We are faced with the politicisation of planning in general, which is increasingly informed by market-based policy. This trend represents a comprehensive policy shift towards more neo-liberal planning content, accompanied by more policies. More principles are appearing, addressing how planning and development are to proceed compared with the content of pre-existing plans. The neo-liberalisation process is thus occurring via means that are contradictory from a neo-liberal perspective.
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| 9. |
- Andreasson, Eskil, 1976-
(författare)
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Mechanics and Failure in Thin Material Layers : Towards Realistic Package Opening Simulations
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The final goal of this PhD-work is an efficient and user-friendly finite element modelling strategy targeting an industrial available package opening application. In order to reach this goal, different experimental mechanical and fracture mechanical tests were continuously refined to characterize the studied materials. Furthermore, the governing deformation mechanisms and mechanical properties involved in the opening sequence were quantified with full field experimental techniques to extract the intrinsic material response. An identification process to calibrate the material model parameters with inverse modelling analysis is proposed. Constitutive models, based on the experimental results for the two continuum materials, aluminium and polymer materials, and how to address the progressive damage modelling have been concerned in this work. The results and methods considered are general and can be applied in other industries where polymer and metal material are present. This work has shown that it is possible to select constitutive material models in conjunction with continuum material damage models, adequately predicting the mechanical behaviour in thin laminated packaging materials. Finally, with a slight modification of already available techniques and functionalities in a commercial general-purpose finite element software, it was possible to build a simulation model replicating the physical behaviour of an opening device. A comparison of the results between the experimental opening and the virtual opening model showed a good correlation.The advantage with the developed modelling approach is that it is possible to modify the material composition of the laminate. Individual material layers can be altered, and the mechanical properties, thickness or geometrical shape can be changed. Furthermore, the model is flexible and a new opening design with a different geometry and load case can easily be implemented and changed in the simulation model. Therefore, this type of simulation model is prepared to simulate sustainable materials in packages and will be a useful tool for decision support early in the concept selection in technology and development projects.
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| 10. |
- Ankre, Rosemarie, 1975-
(författare)
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Friluftslivkonflikter i svenska kustlandskap ur ett planerings- och användarperspektiv : Studier av Luleå och Blekinge skärgårdar
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hav och kust har alltid varit viktiga för oss människor. I svenska kustlandskap har boende, infrastruktur och fiskenäring existerat sedan lång tid tillbaka samtidigt som områdena också varit viktiga för nöje och rekreation. Men mellan olika intressen, samt mellan och inom olika användargrupper samt förvaltning, kan det uppstå målkonflikter. Utgångspunkten för den här avhandlingen är att beskriva och analysera eventuella målkonflikter kopplat till friluftsliv utifrån både ett planerings- och ett användarperspektiv genom två fallstudier i Luleå och Blekinge skärgårdar. Friluftslivet är en del av samhället och dess relevans för fysisk och mental återhämtning ger planering och förvaltning av friluftsliv ett ökat politiskt stöd, samtidigt som tidigare forskning visat att friluftsliv är stark i retoriken - men svag i planeringspraktiken. Därför behövs kunskap som kan utveckla planering och förvaltning av friluftsliv i svenska kustlandskap.Resultaten från den här avhandlingen visar att användarnas perspektiv på målkonflikter i Luleå och Blekinge skärgårdar ännu inte till stora delar har inkluderats i den kommunala planeringen. En slutsats är alltså att det finns skillnader i hur konflikter i samband med friluftsliv beskrivs och identifieras i den fysiska planeringen jämfört med användarnas upplevelser. Det har betydelse för förståelsen av friluftlivskonflikter och hanteringen av dessa. Förutom analys och diskussion av konflikter kopplat till friluftsliv, ingår en fördjupande studie av buller och tystnad som konflikt. Upplevelserna av lugn och ro samt tystnad är centrala för användarna i Luleå och Blekinge skärgårdar. Ett problem som avslöjas är att metoder med decibelnivåer inte avgör skillnader i buller som upplevelse i sig. Upplevelsen av buller och tystnad är nämligen subjektiv. Även zonering undersöks som ett planerings- och förvaltningsverktyg för att hantera friluftslivkonflikter i svenska kustlandskap. Som denna avhandling visar, finns det flertalet exempel på olika sorters zonering i Luleå och Blekinge skärgårdar. När man i planering och förvaltning utgår från ett perspektiv där naturvård och bevarande är utgångspunkterna, så måste ytterligare värderingar och verktyg inbegripas som att inkludera användare med deras olika behov, upplevelser och aktiviteter som äger rum i skärgårdarnas landskap. Att landskapet i sig är av betydelse syns också i resultaten. I fallstudiernas översiktsplaner markeras det värdefulla, attraktiva och unika med skärgårdslandskapet, medan användarna betonar det äkta, naturliga och opåverkade landskapet som grund för deras friluftsupplevelser.Den här avhandlingen tillför kunskap om spänningen mellan olika attityder och synsätt i den fysiska planeringens processer, förvaltning samt friluftslivets användare i svenska kustlandskap. Avhandlingen är också ett tillägg till tidigare kunskap om zonering som ett sätt att hantera konflikter i svenska kustlandskap, där särskilt användarperspektivet är en viktig del. Avhandlingen bidrar även till en grundläggande översikt av fysisk planering i relation till friluftsliv.
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