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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.
431

Reconfigurable Band-pass Comb-line Filter Design

Li, Jinjing January 2020 (has links)
No description available.
432

Layoutförändring baserat på Lean / Layout improvement based on Lean

Balata, Diar, Butty, Laith January 2019 (has links)
Verkstadsindustrin är en bransch i ständig utveckling. Utvecklingen har gjort så att många företag blivit tvungna att tillämpa olika filosofier och principer för att kunna hänga med sina konkurrenter. En av dessa filosofier är Lean Production. Scania är ett av de företag som tidigt bestämde sig för att tillämpa Lean. Det slutade upp med att de tolkade den på sitt eget sätt vilket bildade Scania Production System. En avdelning som inte tillämpar Scanias sätt att arbeta med Lean på bästa sätt är avdelning Fo1:3 på chassi. Här finns det brister som inte uppfyller det Lean-tänk som Scania eftersträvar. Layouten på avdelningen tillför många problem. Det finns mängder av slöserier på området. Arbetsbelastning, gångtiden och trivsel är några exempel på vad som brister på avdelningen. På grund av detta ville chassi implementera en ny layout och därför gavs en uppgift att först kartlägga det interna och externa flödet för att se exakt var bristerna fanns för att sedan komma med layoutförslag. Layoutförslagen som gavs var på ett eller annat sätt grundade i Lean. De utgick dock från olika prioriteringar, som exempelvis att minska gångtiden eller att försöka förbättra den sociala aspekten. I slutändan gavs fem olika layoutförslag. Två av dessa layoutförslag föreslog en förflyttning av hela avdelningen närmare line. Detta, eftersom det ansågs vara det bästa alternativet utifrån Lean-perspektivet. Det var också dessa förslag som Scania ansåg vara de bästa. Det blev dock tydligt att dessa förslag också var de mest svårimplementerade eftersom en förflyttning av en hel avdelning är något som kostar mängder av resurser och tid. Layoutförslag 5 ansågs enhälligt vara det optimala förslaget. Det var också den layout som skulle kräva mest arbete då inte bara stationen skulle flyttas utan det skulle också tvinga fram en helt ny standard som montörerna skulle vara tvungna att jobba efter eftersom nya stationer skulle införas. Alla var i slutändan överens om att förslag 5 skulle i den bästa av världar ge det bästa resultatet. Det finns däremot många hinder som måste övervinnas för att det ska bli verklighet. / The manufacturing industri is a trade in constant development. The development has forced many companies to apply different philosophies and principles to make sure that they stay side by side with their competitors. One of these philisophies is Lean Production. Scania is one of the companies early on, decided to implement Lean. They ended up interpreting it in their own way which formed the Scania Production System. A department that unfortunately does not optimaly apply Scania’s way of working with Lean is Fo1:3 in the chassis facotory. There are many deficiencies here that do not meet the Lean principles that Scania strives for. The layout of the department has many problems. There is a lot of waste that goes on in the area. Workload, walking time and well-being are just some of the examples of what is lacking quality in the department. Because of all this there is a will from Scania to implement a new layout and therefore a task was given to firstly map the internal and external flow to identify exactly where the deficiencies existed. The task after the deficiencies were mapped out and identified was to come up with some suggestions for a new layout. The suggestions of layouts that were given were all in some way based on Lean. There were however different priorities in each suggestion of layout such as reducing the walking time or improving the social aspect. Five different suggestions of layouts were given. Two of these suggestions suggested moving the entire department closer to the line. This is because it was considered the best alternative when looking at it from the perspective of Lean. These were also the options that Scania considered the best. However, it became clear that these proposals were also the most difficult to implement because a transfer of an entire department is both resource and time consuming. Proposal 5 was seen unanimously as the optimal option. It was coincidentally the option that would require most work since not only does the station need to to be moved, it would also require the assemblers to learn a whole new standard of work because new stations would be introduced. Ultimately, everyone was in agreement that option 5 would in the best of worlds also give the best result. There are however many obstacles that have to be overcome in order for it to become reality.
433

Validation of Top of the Line Corrosion Prediction Model Using Laboratory and Field Measurements

Kaewpradap, Ussama January 2012 (has links)
No description available.
434

Analysis of Simulation tool for Future Flexible Assembly lines

Danielsson, Robin January 2022 (has links)
Volvo trucks can be ordered with many options to meet customers' demands. This challenges the efficiency of the manufacturing process, especially at the final assembly line where bare chassis are customised with parts and accessories. In the future, assembly lines may be more flexible to allow for assembly of different parts at higher efficiency. This thesis presents problem areas in traditional assembly lines and proposes a proof-of-concept for future flexible assembly line sequencing, as well as a computer simulation tool with the capability to evaluate variances in production capacity when trucks of different size and parts are assembled in consecutive order. Virtual models of flexible assembly lines are constructed as part of a software solution and used to simulate production sequences of varying truck configurations. Data collected from all simulations show a correlation between production capacity and the order in which vehicles are produced. The assembly line configuration itself has also shown to greatly impact efficiency and might lead to an improvement of at least 39%, as well as limitations of tools and workers with specific capabilities. However, the presented performance numbers do not represent all possible simulation outcomes, which beyond the assembly line configuration also depend on things like product complexity and the assembly sequence of individual products.
435

Controllerns roll : ur ett hållbarhetsperspektiv / The role of the controller : from a sustainability perspective

Amso, Jina, Muka Mabundi, Princesse January 2023 (has links)
Background: Sustainability has become a global trend that has affected people, companies and organizations around the world. Most organizations today integrate sustainability into their operations in various ways. The role of a controller undergoes constant development where the controller's role nowadays includes several strategic tasks. The role has changed over the years where the duties have been affected by global trends, such as sustainability. Purpose: This study aims to create a greater understanding of how an organization's sustainability work has affected the role of the controller and how sustainability is implemented in practice by the controller in the organization. Methodology: The methodology that this study uses is based on a qualitative method where semi-structured interviews have been conducted with eleven controllers from various organizations. A thematic analysis has then been used to categorize the results. Result: The results of the study show that sustainability has affected the controller's role in an indirect way, where the controller's working methods have become more sustainable while the actual tasks of the controller have remained unchanged. On the other hand, the study shows that the controller has embraced financial sustainability while the other two dimensions of sustainability have been neglected. The result shows that the controller has a certain collaboration with the organization's sustainability officer. This collaboration is based on the controller contributing his/her expertise within the financial aspect while relying on the sustainability officer to be responsible for the other two dimensions of sustainability. Recommendations för further studies: For further research, we make recommendations to investigate whether sustainability integration in the controller's work differs if the controller works in the private sector or the public sector. Another suggestion is to investigate whether the three dimensions of sustainability are integrated in the duties of a sustainability controller. / Bakgrund: Hållbarhet har blivit en global trend som har påverkat människor, företag och organisationer runt om i världen. De flesta organisationer numera integrerar hållbarhet i deras verksamheter på olika sätt. Controllerrollen genomgår ständigt utveckling där rollen nu för tiden innefattar flera strategiska arbetsuppgifter. Controllerrollen har därmed förändrats genom åren där arbetsuppgifterna har blivit påverkade av globala trender, såsom hållbarhet. Syfte: Denna studie syftar till att skapa större förståelse över hur en organisations hållbarhetsarbete har påverkat controllerns roll samt hur implementeras hållbarhet i praktiken av controllern i organisationen. Metod: Metoden som denna studie använder sig av bygger på en kvalitativ metod där semi-strukturerade intervjuer har genomförts med elva controller från olika organisationer. En tematisk analys har sedan använts för att kategorisera resultatet. Resultat: Studiens resultat visar att hållbarhet har påverkat controllers roll på ett indirekt sätt där controllerns arbetssätt har blivit mer hållbart medan själva arbetsuppgifterna av controllern har förblivit oförändrade. Å andra sidan visar studien att controllern har anammat den ekonomiska hållbarheten medan de två andra dimensionerna har försummats. Resultatet visar också att controllern har ett visst samarbete med organisationens hållbarhetsansvariga. Samarbetet bygger på att controllern bidrar med hans/hennes expertis inom den ekonomiska aspekten medan hen förlitar sig på att hållbarhetsansvariga ansvarar för de andra två dimensionerna av hållbarhet. Förslag för framtida forskning: För vidare forskning ger vi rekommendationer om undersöka huruvida hållbarhetsintegrering i controllerns arbete skiljer sig om controllern jobbar i privata sektorn eller den offentliga sektorn Ett annat förslag är att undersöka huruvida hållbarhetens tre dimensioner integreras i arbetsuppgifterna av en hållbarhetscontroller.
436

SCIENCE TEACHERS' PERCEPTION OF VIRTUAL HIGH SCHOOL INSTRUCTION

Jayaraman, Usha P. January 2002 (has links)
No description available.
437

Line Tension and Entropy for Molecularly Thin Liquid Crystal Films at Temperatures Corresponding to Less-Ordered Bulk Phases

Yarzebinski, Joseph Santiago 04 August 2016 (has links)
No description available.
438

Dietary Amino Acid Concentrations for 2- to 20-Week-old Turkeys, Meleagris

Aimiuwu, Osagie Christopher 27 September 2010 (has links)
No description available.
439

Applikationer för effektiv inlinekontroll inom svetsande industri : Möjligheter och utmaningar vid implementering av nya kontrollmetoder / Applications for efficient inline control in the welding industry : Opportunities and challenges in implementing new control methods

Lindén, Jonathan, Öbrink, Erik January 2021 (has links)
Svetsning är en viktig fogningsmetod, och kvalitet på svetsar kan ha hög inverkan på prestanda och livslängd för svetsade produkter. För att kunna garantera att svetsar lever upp till de krav som ställs används ofta oförstörande provning. Traditionella oförstörande provningsmetoder kan dock vara oprecisa, långsamma och kräva högutbildade operatörer. För att förbättra kontrollen av svetsar utvecklas därför ny mätteknik som snabbare och mer pålitligt kan bedöma svetsars kvalitet. Genom att intervjua företag inom svetsande industri har slutsatsen kunnat dras att det finns behov av tillförlitliga mätmetoder som kan hantera komplexa geometrier, leverera lättolkade data och som är enkla att implementera. Forskningen om kontrollmetoder för svetsar, och tolkning av datan metoderna producerar, är dock i olika tidiga stadium för olika svetsmetoder. Generellt behövs fler tester av utrustning i utmanande förhållanden samt mer forskning som riktar sig åt att lösa de problem som industrin upplever. / Welding is an important joining method, and the quality of welds can have a severe impact on the performance and life span of welded products. In order to guarantee that welds meet their requirements, non-destructive testing is widely used. Traditional non-destructive testing methods can, however, be imprecise, slow and require highly educated operators. New measuring techniques are therefore being developed to inspect faster and more reliably the quality ofwelds. Through interviews with companies in the welding industry, the conclusion can be drawn that there is a need for reliable inspection methods that can handle complex geometry, provide easily interpreted data and that are simple to implement. The research about inspection methods and the data they provide are, however, in different stages of their development, depending on the welding method. There is generally a need for testing of novel measuring equipment in more demanding settings, as well as more research aimed to solve the problems the industry experiences.
440

Optimization of the Assignment of Printed Circuit Cards to Assembly Lines in Electronics Assembly

Bhoja, Sudeer 28 September 1998 (has links)
The focus of this research is the line assignment problem in printed circuit card assembly systems. The line assignment problem involves the allocation of circuit card types to an appropriate assembly line among a set of assembly lines with the objective of reducing the total assembly time. These circuit cards are to be assembled in a manufacturing facility, capable of simultaneously producing a wide variety of printed circuit cards in different production volumes. A set of component types is required for each printed circuit card. The objective is to assign the circuit cards to the assembly line such that the total assembly time, which includes the setup time as well as the processing time required for all card types in a set, is minimized. The focus of this research is to develop an algorithmic strategy for addressing this problem in electronics assembly. This problem involves considering several interrelated decision problems such as assigning printed circuit cards to assembly lines, grouping circuit cards into families to reduce the number of setups, and assigning component types to machines to balance workload. The line assignment models are formulated as large scale mixed integer programming problems and are solved using a branch-and-bound algorithm, supplemented by techniques for improving the solution time. The models and solution approaches are demonstrated using industry representative data sets and can serve as useful decision support tools for process planning engineers. / Master of Science

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