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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.
41

Optimering av rotordrift för värmeväxlare / Optimering av rotordrift för värmeväxlare

Holländer, Anton January 2023 (has links)
No description available.
42

Processförbättring vid tillverkning av konstruktionskeramer

Garvare, Rickard January 1998 (has links)
This thesis is about implementing Design of Experiments in enterprises manufacturing high performance ceramics. The manufacturing of ceramics is a complex process which involves problems with variation in product properties and in process performance. Every system in operation generates information that can be used to improve it. To be able to improve, measurements must be made and recorded data must be transformed into information. Design of Experiments is about performing tests using a minimum of resources to receive a maximum of information about a process or a system. Today most of the development of processes and products is done supported by expensive, and often misleading, one-factor-at-a-time experiments. To examine the possibilities of facilitating implementation of Design of Experiments, case-studies of two Swedish manufacturers of high performance ceramics were carried out. A model of implementing Design of Experiments is presented based on theory and the case-studies. The proposed model consists of three major phases: 1.Planning and education. 2.Pilot project with new ways of working. 3.Assessment, maintenance and improvement. Design of Experiments appears to be a well suited technique for structuring the development of manufacturing high performance ceramics. The implementation of Design of Experiments could be facilitated by long-term planning for process improvement. To make assessment and evaluation possible, process performance should be documented not only after but also before an implementation takes place. Both knowledge about statistics and knowledge about the studied processes should be present in the teams carrying out experiments. / <p>Godkänd; 1998; 20070404 (ysko)</p>
43

Squat Detection in Railway Switches &amp; Crossings Using Point Machine Vibration

Zuo, Yang January 2022 (has links)
Railway switches and crossings (S&amp;Cs) are among the most important high-value components in a railway network and a single failure of such an asset could result in severe network disturbance, huge economical loss, and even severe accidents. Therefore, potential defects need to be detected at an early stage and the status of the S&amp;C must be monitored to prevent such consequences. One type of defect that can occur is called a squat. A squat is a local defect like a dent or an open pit in the rail surface. In this thesis, a testbed including a full-scale S&amp;C and a bogie wagon was studied. Vibrations were measured for different squat sizes by an accelerometer mounted at the point machine, while a boggy was travelling along the S&amp;C. A method of processing the vibration data and the speed data is proposed to investigate the feasibility of detecting and quantifying the severity of a squat. A group of features were extracted to apply isolation forest to generate anomaly scores to estimate the health status of the S&amp;C. One key technology applied is wavelet denoising. The study shows that it is possible to monitor the development of the squat size introduced in the test bed by measuring point machine vibrations. The relationships between the normalised peak-to-peak amplitude of the vibration signal and the squat depth were estimated. The results also show that the proposed method is effective and can produce anomaly scores that can indicate the general health status of an S&amp;C regarding squat defects.
44

ENHANCING AUTONOMOUSUNDERWATER VEHICLE MISSIONDEPENDABILITY THROUGH ADAPTIVEDYNAMIC REDUNDANCY

Barhaido, Matteus January 2024 (has links)
This master thesis presents, suggests, and discusses a novel approach to enhance the mission dependability of Autonomous Underwater Vehicles (AUVs) through Adaptive Dynamic Redundancy (ADR). The AUVs demand improved dependability not only because they operate in harsh and unpredictable waters, but also because mission failures occur, leading to mission aborts and potential loss of valuable data and equipment. The ADR was carefully implemented for AUV thrusters using curated methods. The ADR stands out as it maintains high dependability while utilizing less power consumption, basing this on necessity, needs, environmental data and conditions, thruster health, and mission criticality. By leveraging a switching feature between Dual Modular Redundancy (DMR) and 1-out-of-3 redundancy, ADR aims to minimize the risk of failures while optimizing the power consumption and reducing wear and tear on the thrusters both for their operational and futuristic state. Through the comparative analysis, the ADR has demonstrated its capability to enhance dependability by improving reliability, safety, and operational efficiency of AUVs compared to other standardized redundancy concepts. The findings suggest that ADR not only prevents failures more effectively than TMR and DMR, but also significantly extends the mission’s lifespan and increases overall mission success rates.
45

Elevhälsa – en illusion av kvalitet? : En fallstudie om vilka faktorer som hindrar eller skapar förutsättningar för kvalitets- och systematiskt förbättringsarbete inom elevhälsan

Glad, Annica January 2017 (has links)
Syftet med uppsatsen var att bidra med kunskap kring hur elevhälsan upplever, och förhåller sig till, den stora frihetsgraden när det gäller att kvalitetssäkra och ständigt förbättra hur de omsätter dagens styrning via värdegrund till handling. Den teoretiska referensramen har främst fokuserat på teorier inom kvalitets- och förbättringsområdet samt skolutveckling, tvärprofessionella team, värderingsbaserat ledarskap och styrning och är baserat på sju olika teman: värdegrund, utveckla ett engagerat ledarskap, arbeta med processer, skapa förutsättningar för allas delaktighet, basera beslut på fakta, sätt kunden i centrum, styrning och säkring samt utveckling och förbättring. I teoriavsnittet presenteras även exempel på styrdokument för att ge läsaren en förståelse för vilka ramar elevhälsan har att förhålla sig till. Uppsatsen har i stort strävat efter att följa den kvalitativa forskningsprocessen utifrån kvalitativa fallstudier och Mixed Methods Designs. Som datainsamlingsmetod valdes gruppenkäter och fokusgruppsintervjuer och tre elevhälsoteam med sammanlagt elva medlemmar har deltagit. Metoddesignen bygger vidare från den teoretiska referensramen och är indelad på samma sätt med de sju olika teman. Hantering av data och analys har även utgått från de sju teman och analysen har följt fyra steg som slutligen redovisar en övergripande tolkning av de sammanlagda svaren i enkäten och från fokusgruppsintervjuerna. Författarens slutsats är att olika värdegrund- och- synsätt- värderingssystem som de tre elevhälsoteamens medlemmar uppvisar gör att värdegrunden omsätts på olika sätt i praktiken i de olika skolorna. / The aim of the paper was to contribute knowledge about how student health perceives and relates to the high degree of freedom in quality assurance and continually improving the way in which they translate current governance through value to action. The theoretical frame of reference has focused on theories of quality and improvement, as well as school development, cross-professional teams and value-based leadership and governance, and are divided into seven different themes: value basis, develop a committed leadership, work with processes, create the conditions for everyone's participation, basing decisions on facts, put the customer at the center, control and hedging as well as development and improvement. The theoria section also presents examples of control documents to give the reader an understanding of the framework for student health. The essay has largely sought to follow the qualitative research process based on qualitative case studies and Mixed Methods Designs. As the data collection method, group kits and focus group interviews and three student health teams with a total of eleven members were selected. The method design is based on the theoretical reference frame and is divided in the same way with the seven different themes. Data and analysis management has also been based on the seven areas, and the analysis has followed four steps presents an overall interpretation of the aggregate answers in the survey and from the focus group interviews. The author's conclusion is that different value-based assessment systems that the three student-health members show makes the value base in various ways implemented in practice. / <p>2017-08-16</p>
46

Våga. Våga pröva. Våga pröva nytt. : Modernt ledarskap från politik till praktik

Jidetoft, Nina, Rydström, Lotta January 2017 (has links)
Syftet med denna studie var att bidra med kunskapsutveckling kring framgångsfaktorer och utmaningar för strategiska ledare, inom Polismyndig-heten, för praktiserandet av ett modernt ledarskap. Studiens teoriavsnitt avgränsades till artiklar och litteratur som berör offentligt ledarskap och tillhörande ledarskapsutveckling med avseende på ett tillits-perspektiv – exempelvis; övergången till det moderna ledarskapet, rollen av organisationskulturen samt ständigt förbättringsarbete. Med utgångspunkt i relevant litteratur utformades en intervjuguide som låg till grund för semistandardiserade intervjuer med sex chefer på strategisk nivå i en av Polismyndighetens sju regioner. Utifrån intervjuresultat och relevant litteratur utformades därefter en enkät som skickades ut till 39 strategiska chefer, på motsvarande funktioner, i myndighetens övriga sex regioner. Arbetets omfattande empiri strukturerades utifrån ett hermeneutiskt förhållningssätt. Analysen av empirin beaktade, med utgångspunkt i studiens syfte och forskningsfrågor, såväl resultatet från intervjuerna och enkätunder-sökningen, som studiens teoretiska ramverk. Författarnas slutsats är att såväl framgångsfaktorer som utmaningar för praktiserandet av ett modernt ledarskap, inom Polismyndigheten, i flertalet fall kan ses ur ett kommunikativt perspektiv. Studiens resultat indikerar att dialogen mellan chefer på regional nivå, likväl den som tar plats mellan regional och nationell nivå, uppvisar utvecklingsutrymme. / The purpose of this study was to contribute with knowledge of success factors and challenges for strategic managers, in the Swedish Police Authority, in practicing a ‘modern leadership’. The chapter on theory was limited to articles and literature relating to leadership in the public sector and trust-oriented leadership development – such as the transition to a ‘modern leadership’, the role of organizational culture, and continuous improvement. An interview guide, which was developed based on relevant literature, formed the outline for semi-standardized interviews with six strategic leaders in one of the seven police regions. A questionnaire, deriving on the results from the interviews, was subsequently sent to 39 strategic managers, in corresponding functions, in the authority's additional six police regions. The extensive empirical work was structured in a hermeneutical approach. The analysis took, based on the study’s purpose and research questions, into account the results of the interviews and the questionnaire, as well as the theoretical framework of the study. The authors conclude that both success factors and challenges for practicing a modern leadership within the Police can, in most cases, be seen from a communicative perspective. The results of the study indicate that the dialogue between managers at a regional level, and the dialogue that takes place between regional and national level, shows opportunities for development. / <p>2017-06-28</p>
47

Kartläggning och jämförelse av arbetssätt att hantera kvalitetsbristkostnader i logistikprocessen / Mapping and comparison of working methods to handle cost of poor quality in the logistics process

Hermansson, Joel, Gottschalk, Max January 2017 (has links)
This bachelor thesis has been done in cooperation with IKEA of Sweden in Älmhult. It is about a mapping and comparison study of how different companies handle their cost of poor quality (COPQ) in their logistics processes. In this study, we have collaborated with Electrolux, Gekås and Rusta. IKEA has a high COPQ, this means when poor quality occurs in their processes. This has attracted much attention in recent years and there is room for improvement. The part of the value chain chosen in this project is the logistics process. The purpose of this bachelor thesis is to map IKEA´s logistics process, then compare IKEA´s way of working with other companies through a benchmarking study and finally come up with areas for improvement. This gave the questions: How does IKEA's operate in their logistics process today and handle their cost of poor quality? How do our other partners operate and handle their logistics processes and cost of poor quality? What are the similarities and differences between the different companies? To find out how IKEA operates in their logistics process today, it was decided to make a corporate visit to one of IKEA's CDC:s. Here, a questionnaire has been used to get the information that was needed. Later this questionnaire formed the basis for the survey that was used to gather information from our other partners. To gather information from our partners, we have used benchmarking. This was done to see how our other partner organizations operate today and how they work accordingly to this study. The first step of the benchmarking, was to send out the survey to our partners. Later we followed up with personal interviews and visits. The collected data from the different companies formed the basis of the status report of them all. In the analysis, IKEA has been compared to each of our different partners and a summary of the analysis has been made. With the analysis finished, it has been clear that IKEA has some problems in their logistic process and that the cost of poor quality can decrease. This gave us some areas that IKEA can make improvements in. After that conclusion, forklift damages and packaging design are two areas that IKEA can make big improvements in. / Detta examensarbete har gjorts tillsammans med IKEA of Sweden i Älmhult. Det handlarom en kartläggning och jämförelse av hur olika företag hanterar sinakvalitetsbristkostnader inom logistikprocessen. Våra samarbetspartners i dettaarbetet är Electrolux, Gekås och Rusta
48

Concept Study and Design of a New Torque Calibration Rig

Lidgren, Albin January 2017 (has links)
When buying a new car today, the customer often expects to get a vehiclewith high quality. Each vehicle or engine should therefore be checked toassure quality. The same goes for clutches and couplings. A powerful enginebecomes useless when a clutch slips. Reliable torque measurement istherefore essential to the automotive industry. The herewith Bachelor thesisproposes a new torque calibration rig for online torque measurement in couplingapplications.The concept encompasses a servo motor with its associated electronics, agearbox to create the high torques (3 kNm), a reference torque transducer,and mounting elements or adapters. From the concept generation phase, thethesis includes CAD-models of the torque calibration rig with mathematicalmodels leading to the calculation of the measurement uncertainty of the calibrationsystem.This work was performed at BorgWarner PowerDrive Systems AB in Landskronaduring eight weeks; the two remaining weeks were completed in Lulea.
49

Modeling, Identification and Control of a Wall Climbing Robot Based on Vortex Actuation / Modellering, identifiering och styrning av en väggklättringsrobot baserat på Vortex aktuator

Papadimitriou, Andreas January 2018 (has links)
No description available.
50

Digitalisering av arbetsflöde för avvikelsehantering på inköpt material : En fallstudie utförd på Nolato Cerbo AB i Trollhättan / Digitalization of a workflow for deviation handling for purchased material : A case study performed at Nolato Cerbo AB in Trollhättan

Abbas, Tabassom, Sandblom, Sofia January 2020 (has links)
Ett examensarbete genomfördes på Nolato Cerbo AB i Trollhättan, med målet att utforma ett förslag på ett digitalt arbetsflöde för avvikelsehantering på inköpt material. De frågeställningar som arbetet skulle besvara var: • Kan ett arbetsflöde för avvikelser på inköpt material digitaliseras för att underlätta dokumentering, spårbarhet och hantering av information? • Hur ska arbetsflödet utformas för att uppnå de interna intressenternas krav och behov? • Vilka fördelar respektive nackdelar kan uppstå vid införandet av ett digitalt arbetsflöde? För att kartlägga hur flödet ser ut i nuläget samt problem med flödet, genomfördes intervjuer med de berörda avdelningarna. Intervjuerna tog också upp de anställdas åsikter om ett digitalt flöde. Ett flödesschema skapades och därefter identifierades slöseri i flödet. En benchmarking genomfördes också på Varner Retail Logistics AB, för att se hur ett annat företag arbetar med ett digitalt flöde för avvikelsehantering. Ett nytt flödesschema togs fram för avvikelsehantering på inköpt material, där de manuella delarna digitaliserades. Efter att ett test genomförts med berörd personal kunde det konstateras att det digitala flödet kommer underlätta dokumentering, spårbarhet och hantering av information. De interna intressenternas krav och behov uppfylldes också. Fördelar som respondenterna anser kan uppnås med det digitala flödet var tidsbesparing, ingen manuell pappershantering, snabbare spridning av informationoch att rätt information fylls i från början. Nackdelar som anses kan uppstå är att det kommer ta tid för personalen att lära sig och vänja sig vid det nya arbetssättet, samt begränsningar i mobilapplikationen. Slutsatserna som drogs var att det digitala flödet kommer att kunna användas om det utformas enligt författarnas förslag, men förändringar kan komma att ske i flödet i framtiden. Det kan också finnas personal på Nolato Cerbo AB som känner en osäkerhet inför digitalisering och förändringar. För att implementeringen ska bli lyckad kommer därför utbildning och information om digitaliseringens möjligheter krävas. / A case study was performed at Nolato Cerbo AB in Trollhättan, with the objective to design a suggestion of a digital workflow for deviation handlingfor purchased material. The following questions were issued to fulfil the objective of the case study: • Is a workflow for deviation handling for purchased material possible to digitalize in order to facilitate documentation, traceability and information handling? • How should the workflow be designed in order to reach the involved personnel's requirements and needs? • Which advantages and disadvantages could emerge from the implementation of a digital workflow? To be able to map the current workflow and its issues, interviews with the involved departments were conducted. The interviews also brought up the employees' opinions of a digital workflow. A flowchart was created and waste in the workflow was identified. A benchmarking was performed at Varner Retail Logistics AB, to get an insight of how another company uses a digital workflow for deviation handling. A new flowchart for deviation handling for purchased material was created, where the manual parts of the flow were digitalized. After a test had been performed with concerned employees, it could be stated that the digital workflow will facilitate documentation, traceability and information handling. The requirements and needs for the involved personnel were also fulfilled. Advantages that the respondents consider can be achieved with the digital workflow was time save, no manual handling of paper, a faster distribution of information and that the correct information will be filled in from the beginning. Disadvantages that the respondents consider can emerge is that it will take some time for the employees to learn and adapt to the new way of working and the limitations of the mobileapplication. The conclusions that were drawn was that the digital workflow will be able to be used if it's designed according to the suggestion, although changes to the workflow might be performed in the future. There might also be employees at Nolato CerboAB which afraid of digitalization and changes. For the implementation to be successful, an education and information about the possibilities that digitalization brings will be required.

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