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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Parametric optimization of reinforced concrete slabs subjected to punching shear

Thuresson, Sofia January 2020 (has links)
The construction industry is currently developing and evolving towards more automated and optimized processes in the project design phase. One reason for this development is that computational power is becoming a more precise and accessible tool and its applications are multiplying daily. Complex structural engineering problems are typically time-consuming with large scale calculations, resulting in a limited number of evaluated solutions. Quality solutions are based on engineering experience, assumptions and previous knowledge of the subject.The use of parametric design within a structural design problem is a way of coping with complex solutions. Its methodology strips down each problem to basic solvable parameters, allowing the structure to be controlled and recombined to achieve an optimal solution.This thesis introduces the concept of parametric design and optimization in structural engineering practice, explaining how the software application works and presenting a case study carried out to evaluate the result. In this thesis a parametric model was built using the Dynamo software to handle a design process involving a common structural engineering problem. The structural problem investigated is a reinforced concrete slab supported by a centre column that is exposed to punching shear failure. The results provided are used for comparisons and as indicators of whether a more effective and better design has been achieved. Such indicators included less materials and therefore less financial cost and/or fewer environmental impacts, while maintaining the structural strength. A parametric model allows the user to easily modify and adapt any type of structure modification, making it the perfect tool to apply to an optimization process.The purpose of this thesis was to find a more effective way to solve a complex problem and to increase the number of solutions and evaluations of the problem compared to a more conventional method. The focus was to develop a parametric model of a reinforced concrete slab subjected to punching shear, which would be able to implement optimization in terms of time spent on the project and therefore also the cost of the structure and environmental impact.The result of this case study suggests a great potential for cost savings. The created parametric model proved in its current state to be a useful and helpful tool for the designer of reinforced concrete slab subjected to punching shear. The result showed several solutions that meet both the economical and the punching shear failure goals and which were optimized using the parametrical model. Many solutions were provided and evaluated beyond what could have been done in a project using a conventional method. For a structure of this type, a parametric strategy will help the engineer to achieve more optimal solutions. / Just nu utvecklas Byggbranschen mot mer automatiserade och optimerade processer i projektdesignfasen. Denna utveckling beror till stor del på teknikutveckling i form av bättre datorprogram och tillgänglighet för dessa. Traditionellt sett löses komplexa konstruktionsproblem med hjälp av tidskrävande och storskaliga beräkningar, vilka sedan resulterar i ett begränsat antal utvärderade lösningar. Kvalitets lösningar bygger då på teknisk erfarenhet, antaganden och tidigare kunskaper inom ämnet.Användning av parametrisk design inom ett konstruktionsproblem är ett sätt att hantera komplexa lösningar. Dess metod avgränsar varje problem ner till ett antal lösbara parametrar, vilket gör att strukturen kan kontrolleras och rekombineras för att uppnå en optimal lösning.Denna avhandling introducerar begreppet parametrisk design och optimering i konstruktionsteknik, den förklarar hur programvaran fungerar och presenterar en fallstudie som genomförts för att utvärdera resultatet. I denna avhandling byggdes en parametrisk modell med hjälp av programvaran Dynamo för att hantera en designprocess av ett vanligt konstruktionsproblem. Det strukturella problemet som undersökts är en armerad betongplatta som stöds av en mittpelare, utsatt för genomstansning. Resultaten används för att utvärdera om en bättre design med avseende på materialanvändning har uppnåtts. Minimering av materialanvändning anses vara en bra parameter att undersöka eftersom det ger lägre kostnader och/eller lägre miljöpåverkan, detta undersöks under förutsättning att konstruktionens hållfasthet bibehålls. En parametrisk modell gör det möjligt för användaren att enkelt modifiera en konstruktionslösning med avseende på olika parametrar. Detta gör det till det perfekta verktyget att tillämpa en optimeringsprocess på.Syftet med denna avhandling var att hitta ett mer effektivt sätt att lösa ett komplext problem och att multiplicera antalet lösningar och utvärderingar av problemet jämfört med en mer konventionell metod. Fokus var att utveckla en parametrisk modell av en armerad betongplatta utsatt för genomstansning, som kommer att kunna genomföra optimering med avseende på tid som spenderas på projektet och därmed också kostnaden för konstruktionen och miljöpåverkan.Resultatet av denna fallstudie tyder på att det finns en stor möjlighet till kostnadsbesparingar och anses därför vara ett mycket hjälpsamt verktyg för en konstruktör. Resultatet visade flera lösningar som uppfyllde de konstruktionsmässiga kraven samtidigt som de gav en lägre materialanvändning tack vare optimeringen. Många lösningar tillhandahölls och utvärderades utöver vad som kunde ha gjorts i ett projekt med en konventionell metod. En parametrisk strategi kommer att hjälpa ingenjören att optimera lösningen för en konstruktion av denna typ.
62

Dissecting the Genetic Basis of Systemic Lupus Erythematosus : The Pursuit of Functional Variants

Delgado Vega, Angélica María January 2013 (has links)
Systemic lupus erythematosus (SLE) is a chronic and systemic autoimmune disease that primarily affects women during the childbearing years. SLE is characterized by the production of autoantibodies against nucleic acids and their interacting proteins. The exact molecular mechanisms leading to the breakdown of self-tolerance remain to a large extent unknown, but it is well established that they are influenced by both non-genetic (i.e. environmental and hormonal) and genetic factors. SLE is a complex, polygenic disease. Several susceptibility variants have been identified in SLE. However, the functional role in disease pathogenesis for the majority of them remains largely unknown. This thesis includes case-control association studies where the role of the genes TNFSF4 (Paper I), STAT4 (Paper II), CD226 (Paper III), and BLK (Papers IV and V) in the susceptibility of developing SLE was investigated. The primary focus was on the identification of the functional variants underlying the association. For each of these genes, fine mapping was performed using single nucleotide polymorphisms (SNPs), the linkage disequilibrium (LD) was characterized, and the association was narrowed down to specific haplotypes by means of several different statistical genetic strategies. Candidate variants were prioritized for further functional analysis on the basis of their potential effect on the gene function, their association, and/or biological plausibility. In Paper I, the association of TNFSF4 with SLE was validated and attributed to a risk haplotype tagged by SNPs rs1234317-T and rs12039904-T. Paper II provides evidence supporting the presence of at least two independent genetic effects within the STAT4 gene represented by rs3821236-A and rs7574865-A, which correlated with increased levels of gene expression. In Paper III, a functional allele in CD226 (rs727088-C) was identified, which was responsible for decreased levels in both mRNA and protein expression. In Paper IV, two independent genetic effects in the BLK gene were demonstrated. The first one comprised multiple regulatory variants in high LD that were enriched for NFκB and IRF4 binding sites and correlated with low BLK mRNA levels. The second was a low-frequency missense substitution (Ala71Thr) that decreased the BLK protein half-life. In Paper V, a genetic epistatic interaction between BANK1 rs10516487 (GG) and BLK rs2736340 (TT+TC) was demonstrated. Additional molecular analyses established that these molecules interact physically.   These studies have contributed to the dissection of the genetic architecture of SLE. They highlight the allelic heterogeneity of the disease and provide functional links to the associated variants, which has significantly aided in the understanding of SLE disease pathogenesis.
63

Individuation : Ontogenes : Prolegomena till Gilbert Simondons genetiska ontologi

Sehlberg, Johan January 2011 (has links)
The following text constitutes an attempt to present the French philosopher Gilbert Simondon's genetic ontology through an account of his reconfiguration of the problem of individuation in his doctoral thesis from 1958, L'individuation à la lumière des notions de forme, information, potentiel, métastabilité. The intention is to show how Simondon through this reconfiguration of a classical philosophical problem – in which concepts and schemas from contemporary physics and technology is utilised in a critique of the bi-polar hylomorphic schema as its traditional, substantialistic solution – becomes able to articulate an anti-substantialistic and anti-reductionistic ontogenesis as first philosophy. A systematic philosophical conception that according to Simondon precedes every critical investigation of the subject as well as every scientific ontology – not by establishing a pre-critical position, but by exceeding Kant's critical position: that is, through a displacement toward a conception of the transcendental conditions for the genesis of being and thought as real conditions, rather than conditions of mere possibility. A displacement that in turn appears to respond to the question that frames this basic account of important concepts and schemas in Simondon, namely: in what sense and to what extent is it necessary for philosophical thought to be thought and developed in relation to other forms of thought?
64

Procedural Generation of Levels with Controllable Difficulty for a Platform Game Using a Genetic Algorithm / Procedurell generering av banor med kontrollerbar svårighetsgrad till ett platformspel med hjälp av en genetisk algoritm

Classon, Johan, Andersson, Viktor January 2016 (has links)
This thesis describes the implementation and evaluation of a genetic algorithm (GA) for procedurally generating levels with controllable difficulty for a motion-based 2D platform game. Manually creating content can be time-consuming, and it may be desirable to automate this process with an algorithm, using Procedural Content Generation (PCG). An algorithm was implemented and then refined with an iterative method by conducting user tests. The resulting algorithm is considered a success and shows that using GA's for this kind of PCG is viable. An algorithm able to control difficulty of its output was achieved, but more refinement could be made with further user tests. Using a GA for this purpose, one should find elements that affect difficulty, incorporate these in the fitness function, and test generated content to ensure that the fitness function correctly evaluates solutions with regard to the desired output.
65

Neurala nätverk försjälvkörande fordon : Utforskande av olika tillvägagångssätt / Neural Networks for Autonomous Vehicles : An Exploration of Different Approaches

Hellner, Simon, Syvertsson, Henrik January 2021 (has links)
Artificiella neurala nätverk (ANN) har ett brett tillämpningsområde och blir allt relevantare på flera håll, inte minst för självkörande fordon. För att träna nätverken användsmeta-algoritmer. Nätverken kan styra fordonen med hjälp av olika typer av indata. I detta projekt har vi undersökt två meta-algoritmer: genetisk algoritm (GA) och gradient descent tillsammans med bakåtpropagering (GD & BP). Vi har även undersökt två typer av indata: avståndssensorer och linjedetektering. Vi redogör för teorin bakom de metoder vi har försökt implementera. Vi lyckades inte använda GD & BP för att träna nätverk att köra fordon, men vi redogör för hur vi försökte. I resultatdelen redovisar vi hur det med GA gick att träna ANN som använder avståndssensorer och linjedetektering som indata. Sammanfattningsvis lyckades vi implementera självkörande fordon med två olika typer av indata. / Artificial Neural Networks (ANN) have a broad area of application and are growing increasingly relevant, not least in the field of autonomous vehicles. Meta algorithms are used to train networks, which can control a vehicle using several kinds of input data. In this project we have looked at two meta algorithms: genetic algorithm (GA), and gradient descent with backpropagation (GD & BP). We have looked at two types of input to the ANN: distance sensors and line detection. We explain the theory behind the methods we have tried to implement. We did not succeed in using GD & BP to train ANNs to control vehicles, but we describe our attemps. We did however succeeded in using GA to train ANNs using a combination of distance sensors and line detection as input. In summary we managed to train ANNs to control vehicles using two methods of input, and we encountered interesting problems along the way.
66

Rörelseaktivitet hos regnbågar (Oncorhynchus mykiss) med olika antal eumelaninfläckar, utsatta för stressande sportfiske / Locomotor activity of rainbow trout (Oncorhynchus mykiss) with different numbers of eumelanic skin spots, exposed to the stressor sport fishing

Gesslin, Enar January 2023 (has links)
Rainbow trout (Oncorhynchus mykiss) are introduced in large parts of the world and are commonly farmed for consumption as well as a valued sport fish. Many species of salmonids show large intraspecific variation in pigmentation, which has been shown to correlate with stress response and several other behavioral traits. In this study, the behavior and stress response of rainbow trout linked to pigmentation is investigated, depending on previous sport fishing experience. Through data from a previous study on rainbow trout in semi-natural ponds, locomotor activity was measured as a proxy of stress, under three different sport fishing treatments. From previous photos, the pigment spots of each rainbow trout are counted to test the correlation with locomotor activity. In addition, it is tested whether different previous experience of sport fishing means a higher stress response when re-exposed to fishing. No significant relationship between pigment spots and locomotor activity could be obtained for the three treatment groups. However, significant differences in locomotor activity due to angling experience between treatment groups upon re-exposure to fishing were found, with fish that were inexperienced in angling having higher locomotor activity compared to previously caught fish. Sport fishing and catch-and-release had the effect of reducing locomotor activity in rainbow trout, which can be interpreted as fishing could both stress them and trigger the fish's feeding response, depending on previous experience. Fishing is believed to create a passivation due to the negative association of being caught, while fish not previously caught were activated by sport fishing. The study's missing correlation between pigment spots and stress has been both confirmed and denied in other studies and may depend on the origin and the degree of domestication, which means that the correlation within other species of salmonids or fish with different origins would be relevant to investigate. / Regnbåge (Oncorhynchus mykiss) förekommer introducerade i stora delar av världen och är vanliga att odlas för konsumtion samt en uppskattad sportfisk. Många arter av salmonider visar stor intraspecifik variation i pigmentering, vilket visats korrelera med stressrespons och flera andra beteendemässiga karaktärsdrag. I denna studie undersöks regnbågarnas beteende och stressrespons kopplat till pigmentering, beroende på tidigare erfarenhet av sportfiske. Genom data från en tidigare studie på regnbåge i semi-naturliga dammar mäts rörelseaktivitet som indirektmått på stress, under tre olika sportfiskebehandlingar. Från tidigare foton räknas varje regnbåges pigmentfläckar för att testa korrelationen med rörelseaktivitet. Därtill testas om olika tidigare erfarenhet av sportfiske, innebär högre stressrespons vid återexponering för fiske. Inget signifikant samband mellan pigmentfläckar och rörelseaktivitet kunde erhållas för de tre behandlingsgrupperna. Signifikanta skillnader i rörelseaktivitet på grund av erfarenheten av sportfiske mellan behandlingsgrupperna vid återexponering för fiske fanns dock, där fisk som var oerfaren sportfiske hade högre rörelseaktivitet jämfört med fisk som fångats tidigare. Sportfiske och catch-and-release hade effekten att minska rörelseaktiviteten hos regnbågar, vilket kan tolkas som att fisket både kunde stressa och trigga fiskens födorespons, beroende på tidigare erfarenhet. Fisket tros skapa en passivisering på grund av den negativa associationen att bli fångad, medan fisk som inte fångats tidigare aktiverades av sportfisket. Studiens uteblivna samband mellan pigmentfläckar och stress har både bekräftats och dementerats i andra studier och kan bero på ursprung och graden av domesticering, vilket gör att sambandet inom andra arter av salmonider eller fisk med olika ursprung vore aktuellt att undersöka.
67

How to Prepare for Death

Lind Färnstrand, Izabel January 2019 (has links)
Abstract of Master essay - 10 HP Izabel Lind Färnstrand Mentor: Emma Kihl Examinator: Sigrid Sandström How to Prepare for Death In this essay I dwell into the failures of our moral senses in relation to the concept of death. How does modern death culture affect our way of life and our ability to take responsibility for the life and death of others? These questions are formed by these current times and affect both my art practice and my everyday life. When facing death within my family it occur- red to me that my and my family’s relationship to death is failing us. I have become frustra- ted with the fear and silence that seems too natural to my surrounding. Not being able to talk about a part of life that is inevitable seems irrational. It became clear when the lack of under- standing and acceptance of death caused relatives an immense suffering. The struggle seemed unnessesary and urged me to try to understand more, based on their deaths. Seeing how very different the experience of dying can be made me wonder what makes a ”good” death possible for some and others not. From there my interest in the topic death culture and fear emerged, and this essay touches on this in a variety of aspects. I use my personal experiences in combina- tion with thoughts of others to talk of layers of these issues through my artistic practice. This personal method is my way of trying to structure a thinking – in a way that I can use and make sense of it – with a varied level of success. I feel it is important to note that I don’t claim to have any answes. This essay is more an attempt to pose questions around human behaviour. Even though many of these ques- tions have been asked over and over again, throughout different times, I believe it is impor- tant to ask them again and again. As long as the Human is part and violently effecting this suffering world. Many of the thoughts in this essay are based on fragments of ideas by Judith Butler, espe- cielly from her book Frames of War: When is Life Grievable? (2009). I also reference Caitlin Doughty’s From Here to Eternity: Traveling the World to Find the Good Death (2017) and and Sogyal Rinpoche The Tibetan Book of Living and Dying (1992). The themes gathered that I try to make use of in this essay and in my artistic practice are purpose, fear, death, health, happiness, narcissim and resposibility. / Abstract of Artistic work How to Prepare for Death @ Galleri Mejan, Exercisplan 3, october 2019 Media: Spatial installation with a performance (1 h) Materials: Clay, plaster, metal & red plastic film How to Prepare for Death is a spatial installation in one of the gallery rooms of Galleri Mejan. The work includes the whole space of the area, such as the floor and the walls. You step into an altered reality, where the floor is covered with clay that is cracking increasingly over time and windows that are tinted red so that the air you breath seems red. When you enter your eyes need to adjust and after a while it is rather the outside that seems colored, neon green -  the complementary color of red. From the clay there are metal rods sticking out vertically, with plaster sculptures at the end. These sculptures are broken, and resemble body parts with a medical aesthetics. Similar sculptures come out from the walls, like fragile fragments of something that used to be. When you walk around the sculptures the clay crackle under your feet, and crumble into smaller pieces and dust. It is constructed as an ambivalent experience of nothingness, emptiness, ”afterness” and a sanctuary of thoughts. My questions about life and death drive me to investigate how to create spaces for these subjects to feel present, so that we can face our fears.
68

Investigating the Use of Digital Twins to Optimize Waste Collection Routes : A holistic approach towards unlocking the potential of IoT and AI in waste management / Undersökning av användningen av digitala tvillingar för optimering av sophämtningsrutter : Ett holistiskt tillvägagångssätt för att ta del av potentialen för IoT och AI i sophantering

Medehal, Aarati January 2023 (has links)
Solid waste management is a global issue that affects everyone. The management of waste collection routes is a critical challenge in urban environments, primarily due to inefficient routing. This thesis investigates the use of real-time virtual replicas, namely Digital Twins to optimize waste collection routes. By leveraging the capabilities of digital twins, this study intends to improve the effectiveness and efficiency of waste collection operations. The ‘gap’ that the study aims to uncover is hence at the intersection of smart cities, Digital Twins, and waste collection routing. The research methodology comprises of three key components. First, an exploration of five widely used metaheuristic algorithms provides a qualitative understanding of their applicability in vehicle routing, and consecutively waste collection route optimization. Building on this foundation, a simple smart routing scenario for waste collection is presented, highlighting the limitations of a purely Internet of Things (IoT)-based approach. Next, the findings from this demonstration motivate the need for a more data-driven and intelligent solution, leading to the introduction of the Digital Twin concept. Subsequently, a twin framework is developed, which encompasses the technical anatomy and methodology required to create and utilize Digital Twins to optimize waste collection, considering factors such as real-time data integration, predictive analytics, and optimization algorithms. The outcome of this research contributes to the growing concept of smart cities and paves the way toward practical implementations in revolutionizing waste management and creating a sustainable future. / Sophantering är ett globalt problem som påverkar alla, och hantering av sophämtningsrutter är en kritisk utmaning i stadsmiljöer. Den här avhandlingen undersöker användningen av virtuella kopior i realtid, nämligen digitala tvillingar, för att optimera sophämtningsrutter. Genom att utnyttja digitala tvillingars förmågor, avser den här studien att förbättra effektiviteten av sophämtning. Forskningsmetoden består av tre nyckeldelar. Först, en undersökning av fem välanvända Metaheuristika algoritmer som ger en kvalitativ förståelse av deras applicerbarhet i fordonsdirigering och således i optimeringen av sophämtningsrutter. Baserat på detta presenteras ett enkelt smart ruttscenario för sophämtning som understryker bristerna av att bara använda Internet of Things (IoT). Sedan motiverar resultaten av demonstrationen nödvändigheten för en mer datadriven och intelligent lösning, vilket leder till introduktionen av konceptet med digitala tvillingar. Därefter utvecklas ett ramverk för digitala tvillingar som omfattar den tekniska anatomin och metod som krävs för att skapa och använda digitala tvillingar för att optimera sophämtningsrutter. Dessa tar i beaktning faktorer såsom realtidsdataintegrering, prediktiv analys och optimeringsalgoritmer. Slutsatserna av studien bidrar till det växande konceptet av smarta städer och banar väg för praktisk implementation i revolutionerande sophantering och för skapandet för en hållbar framtid.

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