Concentrically braced frames with replaceable brace modules (RBMs) have the potential of improving the constructability of braced frames, mitigating the structural damage during earthquakes, and minimizing the time of post-earthquake repairs. To fill the gaps between the component-level performance of RBMs and system-level behaviour of SCBFs with RBMs, this thesis focused on the overall system-level seismic performance of SCBFs with RBMs in three steps. Firstly, the effects of beam-column connection fixity on the behaviour of three SCBFs were investigated to determine what level of fixity, if any, is required to ensure adequate collapse capacity of an SCBF. Secondly, the effects of column design parameters on braced frame seismic performance were investigated, where two different brace-to-frame connections were considered: 1) conventional gusset plate connection and 2) the newly proposed connection detail with RBMs. Detailed numerical modelling was undertaken to develop improved provisions for designing columns in SCBFs. Finally, a large-scale experimental program was conducted to evaluate the seismic performance of braced frames with initial and replaced RBMs where realistic boundary conditions were provided. Three different beam-column connections that can be used in SCBFs with RBMs were designed and tested. Based on the current work, the recently proposed concept of replaceable brace modules, accompanied by the recommended methods for designing columns and detailing beam-column connections, appears to be a promising approach. The fabrication and installation are simpler, the seismic performance is similar to that of SCBFs with currently accepted connection detailing, and the approach can increase the post-earthquake reparability of steel concentrically braced frames. / Dissertation / Doctor of Philosophy (PhD)

Large-scale infrastructure projects are risky ventures, often subjected to poor performance. Time and cost are often escalating beyond estimation while quality and benefits remain unchanged. However, little is known about the project performance in the district heating sector, which serves as basic infrastructure and plays an important role in regional energy transitions. This thesis aims to explore the project performance of large-scale infrastructure projects within the energy sector, particularly the district heating setting to enhance the knowledge of large-scale project performance, and further explore what factors contribute to explaining the performance of large-scale projects within this setting. To fulfil the purpose of this thesis, a multiple case study was conducted in a Swedish district heating setting. A review of relevant literature served as a complement to the primary data retrieved from the cases, laying a theoretical foundation for analysis. The empirical study consists of three parts. The first phase consisted of 18 interviews conducted with people at various positions within the case company to get a holistic picture of the problem and to select the nine cases focused on within this study. The second phase consisted of gathering qualitative and quantitative data on project performance, while the last phase consisted of nine in-depth interviews with the project managers of the nine selected projects. This thesis found a varying project performance, with a mean cost escalation of 12.9 percent and a time increase of 140 days on average. Similar to other studies, large-scale energy infrastructure projects have a tendency to fail rather than succeed when compared to the Iron Triangle criterias, cost, time and quality. Insufficient planning and procurement, weak leadership and ill-performing contractors are significant factors that have a large negative impact on performance. In addition, scope change, environmental context and luck are also shown to impact project performance. Limited evidence on whether political factors have a substantial impact on project performance has been found, in contrast to a large segment within earlier literature. Strong teamwork, both internally within the project team and externally with contracting parties can help neutralise any poor performance caused by any of the above-mentioned factors. The thesis contributes to the literature by discussing large-scale energy infrastructure performance. It is known that large-scale projects are complex and uncertain endeavours and by analysing project performance, knowledge can be enhanced not only on what went wrong but also on what went right. With a global sustainability transition and decarbonisation, energy infrastructure is going to experience large investments in the years to come. With this in mind, developing the most sustainable best practices and prudent project objectives can help project managers to embrace uncertainty and make the right decisions to enhance project performance. / Storskaliga infrastrukturprojekt är ofta riskfyllda, och levererar sällan i linje med uppsatta mål. Både projektens tid och kostnad eskalerar långt bortom de initiala estimeringar som gjorts medan kvalitén och investeringens förmåner förblir oförändrade. Fjärrvärmesektorn är en viktig del i Sveriges energisystem men behöver ständigt tackla dyra investeringar med låg lönsamhet. Syftet med denna uppsats var att undersöka storskaliga infrastrukturprojekt inom energisektorn, i synnerhet med fokus på fjärrvärme, för att öka kunskapen om projektens resultat gällande tid, kostnad och kvalité samt att utforska vilka faktorer som påverkar utfallet av storskaliga projekt i denna sektor. För att uppfylla syftet med denna studie så valdes en flerfallsstudie med en kombination av kvalitativ och kvantitativ metod tillsammans med en genomgång av relevant litteratur. Litteraturstudien fungerade som ett komplement till den projektspecifika informationen som samlades in och la grunden till det teoretiska ramverk som användes under analysen. Den empiriska studien bestod av tre delar. I den första delen utfördes 18 intervjuer med anställda på olika positioner inom företaget, syftet med dessa intervjuer var att få en holistisk bild av problemet samt att välja ut de nio projekt som analyserades vidare. Fokus för studiens andra del var att samla in kvantitativa och kvalitativa data för de nio projekten medan den sista delen bestod av intervjuer med projektledarna för de nio utvalda projekten. Studien visade på ett varierande resultat gällande projektens utfall där medelvärdet för kostnadsöverskridningar var 12,9 procent och medelvärdet för tidsfördröjningar var 140 dagar. I linje med tidigare studier så har storskaliga energiprojekt en tendens att misslyckas gällande att uppfylla både tidoch kostnadskriterier. De främsta faktorerna som påverkade projektens utfall var otillräcklig planering, en ofördelaktig inköpsstrategi, svagt ledarskap samt entreprenörer som presterade dåligt. Utöver dessa så påverkade även förändringar av projektets omfattning, projektets omgivande kontext och ren och skär tur projektens utfall. Politiska faktorer var ej en framträdande faktor i denna studie, till skillnad från tidigare litteratur där politiska faktorer ofta är i fokus. En sammansvetsad projektgrupp, både internt och externt med avtalade parter, visade sig kunna neutralisera de ovan nämnda faktorerna så att det övergripande utfallet ändå blev bra. Storskaliga energiprojekt är både komplexa och osäkra investeringar. Genom att studera projekts utfall och prestation kan insikter fås inte bara kring vad som gick fel utan också kring vad som gick rätt. Stora investeringar kommer att krävas inom energisektorn under kommande år för att möjliggöra den hållbara omställning som krävs på global nivå. Att etablera bra och hållbara metoder med försiktiga projektmål kan hjälpa projektledningen att flytta fokus från att minimera riskerna till att istället omfamna osäkerheten och fatta rätt beslut på bra grunder.

The transition towards flexible work arrangements, notably work-from-home (WFH) practices, has prompted significant discourse on their potential to reshape urban landscapes. While existing urban growth models (UGM) offer insights into environmental and economic impacts, There is a need to study the urban phenomena from the bottom-up style, considering the essential influence of individuals' behavior and decision-making process at disaggregate and local levels (Brail, 2008, p. 89). Addressing this gap, this study aims to comprehensively understand how evolving work modalities influence the urban form and land use patterns by focusing on socioeconomic and environmental factors. This research employs an Agent-Based Model (ABM) and Artificial Neural Network (ANN), integrated with GIS technologies, to predict the future Land Use and Land Cover (LULC) changes within Roanoke, Virginia. The study uniquely explores the dynamic interplay between macro-level policies and micro-level individual behaviors—categorized by employment types, social activities, and residential choices—shedding light on their collective impact on urban morphology. Contrary to conventional expectations, findings reveal that the current low rate in WFH practices has not significantly redirected urban development trends towards sprawl but rather has emphasized urban densification, largely influenced by on-site work modalities. This observation is corroborated by WFH ratios not exceeding 10% in any analyzed census tract. Regarding model performance, the integration of micro-agents into the model substantially improved its accuracy from 86% to 89.78%, enabling a systematic analysis of residential preferences between WFH and on-site working (WrOS) agents. Furthermore, logistic regression analysis and decision score maps delineate the distinct spatial preferences of these agent groups, highlighting a pronounced suburban and rural preference among WFH agents, in contrast to the urban-centric inclination of WrOS agents. Utilizing ABM and ANN integrated with GIS technologies, this research advances the precision and complexity of urban growth predictions. The findings contribute valuable insights for urban planners and policymakers and underline the intricate relationships between work modalities and urban structure, challenging existing paradigms and setting a precedent for future urban planning methodologies. / Doctor of Philosophy / As more people start working from home, cities might change unexpectedly. This study in Roanoke, Virginia, explores how work-from-home (WFH) practices affect urban development. Traditional city growth models look at big-picture trends, but this study dives into the details of workers' individual behaviors and their residential choices. Using advanced computer models such as machine learning and geographic information systems (GIS), predictions are made on how different work arrangements influence where workers live and how cities expand. Surprisingly, fewer people work from home than expected. This hasn't caused cities to spread out more. Instead, Roanoke is expected to become denser in the next ten years because on-site workers tend to live in urban centers, while those who work from home prefer suburban and rural areas and, sometimes, urban. Different work arrangements lead to distinct residential preferences. By including the workers' individual behaviors in the models, the model's accuracy increased from 86% to 89.78%. Logistic regression analysis highlights the factors influencing land use changes, such as proximity to roads, slopes, home values, and wages. This research helps city planners and policymakers understand working arrangement trends and create better policies to manage urban development. It shows the complex relationship between work practices and city structures, providing valuable insights for future city planning.

Yes / Underpinned by a contemporary view of automotive systems as cyber-physical systems, characterised by progressively open architectures increasingly defined by their interaction with the users and the smart environment, this paper provides a critical and up-to-date review of automotive Integrated Vehicle Health Management (IVHM) systems. The paper discusses the challenges with prognostics and intelligent health management of automotive systems, and proposes a high-level framework, referred to as the Automotive Healthcare Analytic Factory, to systematically collect and process heterogeneous data from across the product lifecycle, towards actionable insight for personalised healthcare of systems. / Jaguar Land Rover funded research “Intelligent Personalised Powertrain Healthcare” 2016-2019

This article deals with the analysis and evaluation of the structural behavior of segmented tower constructions in large-scale experimental investigations. For this purpose, a tower model with dry horizontal joints on a scale of approximately 1:10 is constructed and loaded. The objective of these large-scale investigations is to determine the load-bearing behavior of concrete segment towers subjected to normal force (external prestressing), bending, shear force and torsion and to derive more efficient and realistic design models. The transfer of shear stresses between individual segments is ensured by frictional resistance in the horizontal joints due to prestressing. The current design models are based on plane flange surfaces at the top and bottom of the segments as well as their ideal circular ring shape. This assumes a constant normal stress distribution for the compression connection. Within the large-scale experimental tests, findings for uneven force distribution in the horizontal joints due to prestressing and shear bending were obtained, that have a significant impact on the design models. However, for the evaluation of the results and the projection onto the real construction components, the scale effects must be urgently taken into account.

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第25439号 / 情博第877号 / 新制||情||147(附属図書館) / 京都大学大学院情報学研究科数理工学専攻 / (主査)教授 山下 信雄, 教授 梅野 健, 准教授 加嶋 健司 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

Large Scale Additive Manufacturing (LSAM) technology has emerged as a transformative force in the manufacturing industry. Using robots and advanced material deposition systems, LSAM facilitates the efficient creation of large-scale components with exceptional precision and reduced production times. Beyond its capacity to manufacture complex structures, this technology drives innovation by fostering the exploration of new materials and designs, opening new frontiers in the aerospace, automotive, and construction sectors. The synergy between robotics and additive manufacturing in LSAM represents a significant advancement toward the future of manufacturing, where customization, efficiency, and sustainability are paramount.  Within the framework of this research, conducted in collaboration with ABB and RISE, a series of tests have been developed to optimize printing parameters when transitioning from one material to another. This study showcases how simple adjustments in the workflow of robotic stations can lead to significant improvements in print quality and increased resource efficiency, paving the way for more precise and sustainable manufacturing.  This research has not only generated valuable insights into the behavior of LSAM under different operating conditions but also provided practical solutions for its continuous improvement. These findings are relevant for the continuous improvement of large-scale additive manufacturing processes and provide important insights for future research in the fields of robotics and advanced manufacturing. Additionally, a systematic methodology has been developed to evaluate and validate results, ensuring the reliability and reproducibility of findings. These achievements solidify the role of LSAM as a fundamental technology in the evolution of the manufacturing industry toward a more efficient and sustainable future.

Bakgrund: Elektrifieringen har resulterat i en ökad efterfrågan av litiumjonbatterier vilket har skapat ett ökat konkurrenstryck på marknaden. För att upprätthålla konkurrenskraften och möta intressenternas förväntningar krävs betydande investeringar från företagets sida. Micropower Group som tillverkar laddare- och litiumjonbatteri är en ledande aktör på marknaden och genomför en superinvestering i en ny produktionsanläggning. Med tanke på att hållbarhet är ett aktuellt ämne har företaget valt att konstruera anläggningen utifrån en grön profil.  Syfte: Syftet med uppsatsen är att analysera och beskriva investeringsprocessens tidiga skeden, samt när och på vilket sätt hållbarhet spelar roll i processen, mer specifikt från initiering till beslut. Genom att utgå från detta syfte belyses även andra icke-finansiella dimensioner som är av betydelse.  Metod: Studien är en kvalitativ fallstudie som har genomfört semistrukturerade intervjuer för att samla in empiriskt material. Respondenterna valdes genom både ett strategiskt urval och ett snöbollsurval. Den teoretiska referensramen består framförallt av böcker, vetenskapliga artiklar från Linnéuniversitets databaser, såsom Google Scholar och OneSearch.  Slutsats: Det ursprungliga motivet bakom superinvesteringen var strävan efter att bibehålla en ledande position på marknaden och leda den gröna omställningen, vilket kräver ökad kapacitet. Emotioner var centrala under investeringsbedömningen och beslutet grundades på strategiska överväganden och dess överensstämmelse med företagets långsiktiga tillväxtstrategi, struktur, kultur och värderingar. Micropower Group integrerade hållbarhet i investeringsprocessens tidiga skeden, framförallt under framdrivning och delvis i beslut, genom att prioritera sociala och miljömässiga fördelar samt arbetsmiljöförbättringar för att stärka företagsimage, långsiktig tillväxt och lönsamhet samt konkurrensfördelar. / Background: Electrification has resulted in an increased demand for lithium-ion batteries, which has created increased competitive pressure on the market. To maintain competitiveness and meet stakeholders' expectations, significant investments are required on the part of the company. Micropower Group, which is a leading manufacturer of chargers and lithium-ion batteries, is making a large-scale super capital investment in a new production facility. Considering that sustainability is a current topic, the company has chosen to construct the facility based on a green profile. Purpose: The purpose of the study is to analyze and describe the early stages of the investment process, as well as when and in what way sustainability becomes decisive in the process, more specifically from initiation to decision. By proceeding from this purpose, other non-financial dimensions that play a role are also highlighted. Method: The study is a qualitative case study that has conducted semi-structured interviews to collect empirical material. Respondents were selected through both strategic and snowball sampling. The theoretical frame of reference mainly consists of books, and scientific articles from Linnaeus University's databases, such as Google Scholar and OneSearch. Conclusion: The original motive behind the super capital investment was the aspiration to have a leading position in the market, which required increased capacity. Emotions were central during the investment assessment and the decision was based on strategic considerations and its consistency with the company's long-term growth strategy, structure, culture, and values. Micropower Group integrated sustainability in the early stages of the investment process, mainly during propulsion and partly in decisions, by prioritizing social and environmental benefits and improvements in the work environment for strengthened corporate image, long-term growth, and profitability as well as a competitive advantage.

Protection of buried pipes is a serious issue that concerns countries around the world. Therefore, there is a need for new soil improvement techniques such as geosynthetic materials installation to protect these pipes from damage. This study used large-scale laboratory tests to study the behaviour of buried pipes. A total of 22 large-scale tests were performed to study the behaviour of buried flexible HDPE pipes with and without void presence under the protection of the geogrid reinforcing layers subjected to incrementally increasing cyclic loading. The presence of voids located at the spring-line of the flexible buried pipes, led to a considerable increase in the soil surface settlement, pressure recorded at the pipe crown, spring-line and invert, pipe deformation and strain recorded in the pipe wall. Increasing the pipe burial depth contributed to significant reductions in the soil surface settlement, pressure recorded at the pipe crown and invert, pipe deformation and strain recorded in the pipe wall. However, the void presence limited the contribution of increasing the pipe burial depth. The inclusion of a geogrid reinforcing layer contributed to a considerable reduction in the soil surface settlement, pressure recorded at the pipe crown, spring-line and invert, pipe deformation and strain recorded in the pipe wall. The use of a combination of geogrid reinforcing layers and increasing the pipe burial depth contributed in diminishing the ground void presence effect, where better pressure distribution inside the system was achieved. Consequently, more protection was provided to the buried pipe.

In this thesis, several heuristics that aim to improve the performance of parallel fault simulation for synchronous sequential circuits have been investigated. Three heuristics were incorporated into a well known parallel fault simulator called PROOFS and the efficiency of the heuristics were measured in terms of the number of faults simulated in parallel, the number of gate evaluations, and the CPU time. The three heuristics are critical path tracing, dynamic area reduction and a new heuristic called two level simulation. Critical path tracing and dynamic area reduction which have been previously proposed for combinational circuits are extended for synchronous sequential circuits in this thesis. The two level simulation that was investigated in this thesis is designed for sequential circuits. Experimental results show that critical path tracing is the most effective of the three heuristics. In addition to the three heuristics, new fault injection and fault ordering methods were suggested to improve the speed of an efficient fault simulator called HOPE. HOPE, which was developed at Virginia Tech is, an improved version of PROOFS. HOPE_NEW, which incorporates the two heuristics performs better than HOPE in the number of gate evaluations and the CPU time. HOPE_NEW is about 1.13 times faster than HOPE for the ISCAS89 benchmark circuits. For the largest circuit, the speedup is about 40 percent. / Master of Science