• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 394
  • 311
  • Tagged with
  • 705
  • 705
  • 705
  • 705
  • 705
  • 91
  • 62
  • 56
  • 53
  • 42
  • 39
  • 36
  • 33
  • 33
  • 32
  • 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.
21

Koppling mellan lagerstorlek och informationshantering i en organisation med varierande lagerbehov : Fallstudie

Karlborg, Sofie January 2018 (has links)
No description available.
22

Estimering av förändrad lagerhållningskostnad när en slutprodukts framställning övergår från att tillverkas enligt en MTO-strategi till en ATO-strategi : En fallstudie utförd hos Bosch Rexroth Mellansel AB

Stjernqvist, Anton, Grant, Jonathan January 2018 (has links)
På dagens hårt konkurantutsatta marknader tvingas företag hitta nya sätt för att kunna tillhandahålla ett större produktsortiment och samtidigt kunna förse sina kunder med produkter på kortare ledtid. För att kunna åstadkomma detta blir det allt vanligare att företag idag styr sin produktion utifrån en assemble-to-order-strategi (ATO). När antalet slutprodukter som framställs utifrån den här tillverkningsstrategin ökar, i syfte att erbjuda dessa på kortare ledtid, krävs det ofta att ett större antal nya komponenter måste lagerhållas samt att kvantiteten av befintligt lagerhållna komponenter måste utökas. Kostnaderna för företaget kommer således att öka, i form av ökad kapitalbindning, som ett resultat av att antal produkter i arbete ökar. Denna uppsatts behandlar en fallstudie som utförts på Bosch Rexroth Mellansel AB, som är en ledande leverantör av stora hydrauliska drivlösningar och som framställer flertalet av sina produkter utifrån en ATO-strategi. Företaget saknar idag ett tillvägagångssätt för att ta reda på vilka ekonomiska konsekvenser som deras lagerhållning av komponenter medför när ytterligare hydraulmotorer erbjuds på kortare ledtid. Utifrån detta, samt det faktum att förädlingsvärdet för deras interntillverkade komponenter är betydligt högre än värdet för deras inköpsartiklar, är syftet med denna studie att undersöka hur Bosch Rexroth Mellansel kan estimera den förändrade lagerhållningskostnaden som uppstår för färdigbearbetade interntillverkade komponenter när fler hydraulmotorer erbjuds på kortare ledtid. Studien genomfördes utifrån en kvantitativ forskningsmetod där data samlades in från fallföretagets affärssystem SAP. Den sammanställda data har i denna studie analyserats utifrån Microsoft Excel och programspråket Python. Baserat på studerad litteratur inom området, empiri och analys har studien resulterat i en metodik som omfattar fyra steg som Bosch Rexroth Mellansel rekommenderas att använda för att estimera den förändrade lagerhållningskostnaden som uppstår när fler hydraulmotorer erbjuds på kortare ledtid. Till följd av hur Bosch Rexroth Mellansel beräknar sina lagernivåer framgick det tydligt att det enbart är en hydraulmotors ingående interntillverkade komponenter som inte lagerhålls som kan komma att ha en inverkan på den förändrade lagerhållningskostnaden, när denna ska erbjudas på kortare ledtid.
23

Bryggtjänst under fartygsförlagd utbildning

Bergström, Patrik January 2018 (has links)
No description available.
24

Safety and mobility of children crossing streets as pedestrians and bicyclists

Johansson, Charlotta January 2004 (has links)
The content of this thesis is safety and mobility of children crossing streets as pedestrians and bicyclists. The risk of fatal injury is higher for pedestrians and bicyclists, especially for children and elderly, than for other road users except motorcyclists. The effect of speed reducing devices installed to increase the safety of pedestrians and bicyclists at marked pedestrian crosswalks are studied and evaluated in before-and-after studies. Design principles of a safe environment for children as pedestrians and bicyclists are suggested based on research in this thesis and on earlier research results. Most important is that actual motor vehicle speeds are no more than 30 km/h, wherever children (regularly) cross streets. / Godkänd; 2004; 20061026 (haneit)
25

Increasing the effectiveness of the tool development process through partnership

Johansson, Charlotta January 2002 (has links)
Partnership is about developing good business relations between two or more companies. It is a simple and effective working method that can be applied in many situations, including developing new products and associated tooling which is the focus of this thesis. The goal with partnership is not to have a cosy relationship between the partners; but rather as an effective way to make money using a simple working method. The work presented in this thesis is the result of a joint project between Luleå University of Technology and the Pressoform consortium. Pressoform was interested in applying the results in the tooling industry in Sweden and therefore funded the research. The aim of the work behind this thesis was to show that by implementing an effective working method, based on partnership, product development lead-times could be reduced without reduction in quality or increased costs. The specific domain of the work was the development process for form tools such as tools for injection moulding, die casting and sheet metal forming. The advantages with working in a partnership include the possibility to achieve a reduced lead-time and at the same time increase quality and reduce the cost by using an effective working method for developing new products. There are however risks with partnerships, it is a more expensive relationship to maintain, customers are more tightly bounded to suppliers. Another risk could be that the customers by tradition have looked for a power relationship, where they control the form of the relationship. On the other hand a partnership may result in customers and suppliers becoming too close and loose the business like attitude. Partnership is a long-term investment and a strategy for the companies involved to make more money in the long term. Personal relations and trust are important in a long-term strategy, since the companies expect to work together for a long period of time. Partnership should therefore only be conducted with companies that are trusted. In addition effective methods should be applied to speed up the development process for the product and tooling. The business process should be conducted without the traditional quotation process, since this is both time- and cost consuming. Instead of using quotes, buying tools on a cost plus basis is far more effective. The product development work must be conducted with active input from all the three parties. It should be conducted in teams to improve communication, the manufacturer and the tool manufacturer being involved in the team to give input in their expertise areas. Using 3D CAD software has been shown to reduce development lead times by 50% compared to using 2D CAD software. Of the five cases followed, a reduction in lead-time was found in three of them. In one case the project failed due to manufacturing problems whilst the last case focused on the effective product development process in general. / Godkänd; 2002; 20070222 (ysko)
26

Towards a method to improve road safety for pedestrians and cyclists especially in child pedestrian environments : a case study in Borås

Johansson, Charlotta January 2001 (has links)
This licentiate thesis deals with traffic safety of pedestrians and cyclists, especially children, in urban areas. The aim is to develop a method based on video recordings to describe road safety and mobility for pedestrians and cyclists, especially children, at intersections in urban areas. It is tested using empirical data from intersections in Borås, Sweden. The amount of incidents and conflicts between vehicles and pedestrians and cyclists are lower for all age groups after reconstruction. Before reconstructions the share of car drivers giving way were low independent of the pedestrians age. The design of an intersection influences the different road users’ behaviour. At intersections where more pedestrians walk on the marked zebra crossing the children are benefited the most. / <p>Godkänd; 2001; 20061101 (ysko)</p>
27

The effect of anti-slip devices on pedestrian safety : method development and practical test

Berggård, Glenn January 2010 (has links)
Every winter, more than 100,000 pedestrians in the Nordic countries receive medical treatment as a result of falls on slippery surfaces. In addition, the risk of injury reduces interest in outdoor activities during the wintertime. Pedestrians injured in single-pedestrian accidents on icy and snowy surfaces also experience more serious injuries than pedestrians injured on other surfaces. Thus, there is a clear need for measures to reduce single-pedestrian injuries and improve the safety of walking, without curtailing the activity, year round. A "slip accident" occurs when a person loses his/her balance. An attempt is normally made to recover one's balance, and the person's balance is either recovered or a fall occurs. An injury may be the consequence of such a fall. The most critical phases of the human gait are the heel strike and the toe-off.Various countermeasures can be used .to reduce the risk of a person slipping and sliding when walking outdoors during the wintertime. Such countermeasures may involve the use of individual equipment, services provided by the community to assist vulnerable road-user groups or the public at large, and policy changes in winter-maintenance practices. Examples of measures targeting individuals include information on the risk of slipperiness, and encouraging the use of (or providing) winter footwear and/or anti-slip devices to be fastened to shoes. The issues considered in this thesis are related to the prevention of injuries from single-pedestrian accidents by a specific measure, the use of anti-slip devices. More specifically, the following questions have been addressed in the studies it is based upon:How can the properties of anti-slip devices be assessed?How can more effective anti-slip devices be developed?Do anti-slip devices improve walking ability and safety?In laboratory investigations, test methods were developed and applied to 33 anti-slip devices to assess the test methods against validated criteria, and to analyse the benefits of using different types of anti-slip devices. The tests were conducted by observing people making standard movements on various surfaces chosen to simulate the variations in winter maintenance standards on walkways: snow on ice, sand on ice, gravel on ice, salt on ice and pure ice. Movements were analysed from observations of video recordings, and subjective rating scales were developed to assess walking safety and walking balance. In addition, in a field study questionnaires were used to record exposure, occurrence of slips/falls, descriptions of the slips/falls that occurred and general experiences of the use of anti-slip devices.The results show that it is possible to record the performance of anti-slip devices for pedestrians in a laboratory setting, and that the method developed for doing this is satisfactory. The methods used, together with friction measurements made by the Finnish Institute of Occupational Health (FIOH), may provide a sound basis for establishing standard methodology for testing anti-slip devices as personal protective equipment.The results from the Laboratory tests can be used to identify favourable designs of anti-slip devices, and indicate that whole-foot devices are the best type, followed by heel devices, for supporting a natural gait. The results from the Field study show that the availability and use of anti-slip devices can promote walking, which is beneficial from a health perspective, and it does not lead to an increased risk of slipping/falling even though it increases exposure. Overall, the results indicate that the use of anti-slip devices is an effective traffic safety countermeasure for reducing single-pedestrian accidents.Aspects that warrant further attention include verification of the effects of anti-slip devices on exposure and the occurrence of falls, and their effects in relation to specific groups such as elderly. / I de Nordiska länderna beräknas mer än 100000 personer uppsöka sjukvård vintertid på grund av fall på snö och is. I Sverige beräknas ca 10000 män och 15000 kvinnor uppsöka sjukvård på grund av skada vid fall på snö och is. Personer skadade i fallolyckor på snö och is har svårare skador och längre konvalescenstid jämfört med fotgängare som faller på barmark. Därför är det viktigt att identifiera preventiva metoder för fallolyckor vintertid och möjliggöra säkra promenader året runt.En fallolycka inträffar när personen förlorar sin balans och alla försök att återfå den misslyckas. En skada kan uppkomma till följd av ett sådant fall. De kritiska momenten i gångcykeln är hälisättningen och fotavvecklingen (avstampet).Olika åtgärder kan vidtas för att reducera fallolyckor vintertid. De kan antingen relateras till åtgärder i miljön som snöröjning, halkbekämpning osv, eller vara inriktade på att stödja individen i form av balansträning, information om väderlek med hög halkrisk, skor med bra egenskaper eller halkskydd. I detta arbete är fokus på att förhindra skador från singelfotgängarolyckor med en individuell åtgärd, halkskydd.Syftet är att besvara följande forskningsfrågor:Hur kan olika egenskaper hos halkskydd testas?Hur kan effektivare halkskydd utvecklas?Förbättrar halkskydd gångförmågan och säkerheten?Halkskydd är av principiellt olika typer: helfotsskydd (vilka täcker hela eller huvuddelen av skons undersida), hälskydd (vilka i huvudsak täcker klacken under skon) samt fotbladsskydd (som i huvudsak täcker främre delen av undersidan på skon). I laboratoriestudier har en testmetodik utvecklats och 33 olika halkskydd har testats. Testbanorna och testcyklerna efterliknar förhållandena i trafikmiljön, speciellt vid anslutning till och på övergångsställen som antas mer fallolycksbelastat. Testerna sker på olika typer av hala ytor för att efterlikna olika driftstandard: grus på is, sand på is, ren is, snö på is samt salt på is. Analys av gångmönster från videoinspelningar har genomförts. Subjektiva metoder har utvecklats för att värdera gångsäkerhet och balans. I en fältstudie användes enkäter för att registrera exponering, förekomsten av halka och fall, beskrivning av halk- och falltillfällena och generella erfarenheter av användningen av halkskydd.Resultaten visar att det är möjligt att registrera egenskaper hos halkskydd i laboratoriemiljö och att de använda metoderna ger tillfredsställande resultat. Testmetoderna har utvärderats i samarbete med FIOH (Finnish Institute of Occupational Health) som utför tester av halkskydd för godkännande enligt EU:s certifieringsregler för personlig skyddsutrustning (CE-märkning). Utvärderingen kan ligga till grund för ett förslag till standardiserad testmetodik för halkskydd.Olika kvaliteter hos halkskydd har kunnat identifieras vid gång på de olika ytorna. Helfotsskydden stödjer bäst en naturlig gång. Hälskydden är näst bäst i att stödja en naturlig gång. Fältstudien visar att de som använde halkskydd hade signifikant högre exponering utan att få en ökade förekomst av halkincidenter/fall. Halkskydd kan antas vara en effektiv trafiksäkerhetsåtgärd för att minska fotgängarolyckor Nya studier rekommenderas för att verifiera effekten av halkskydd på exponering som fotgängare och förekomsten av fallolyckor samt även effekten för olika grupper som t ex äldre. / Godkänd; 2010; 20100518 (glenn); DISPUTATION Ämnesområde: Trafikteknik/Traffic Engineering Opponent: Professor emeritus Christer Hydén, Lunds tekniska högskola Ordförande: Professor Anders Lagerkvist, Luleå tekniska universitet Tid: Torsdag den 16 september 2010, kl 10.00 Plats: F1031, Luleå tekniska universitet
28

Governance for sustainable development of major European transport corridors : The Scandinavian-Mediterranean TEN-T core network corridor

Maria, Öberg January 2017 (has links)
Intermodal road, rail, air and sea transport networks across the European Union (EU) calledTrans-European Networks for Transport (TEN-T) are currently being implemented. Keyelements, which should be implemented by 2030, are the most strategic TEN-T Core networkcorridors. These nine corridors are expected to enhance smoothness and sustainability oftransport across the EU, thereby enhancing cohesion between EU nations, and relate to non-EU nations. In the EU Regulation 1315/2013 a governance framework for implementation ofthe Core network corridors is outlined, which mainly involves appointment of a Europeancoordinator for each corridor, establishment of Corridor forums for consultations, andformulation of work plans and follow-up measures.This framework is now being implemented in practice. A recognised challenge in the processis engaging the numerous, diverse stakeholders. A possible solution is to introduceappropriate elements of complementary governance. Thus, in this doctoral research, suitablecomplementary governance to support the sustainable development of a Core networkcorridor was investigated. Complementary governance, a concept that was developed andrefined during the project, refers here to additional governance in relation to the governanceframework described for the EU Core network corridors in the EU Regulation 1315/2013.To address an identified gap in knowledge on the nature and utility of complementarygovernance a series of studies was carried out. The studies included a study of relevantacademic literature, studies of EU transport policy and implementation documents regardinggovernance and sustainability, a survey of views of Scandinavian-Mediterranean Corridorforum participants, and interviews with stakeholders in the Baltic Sea region. These studiescollectively constitute a case study, focusing on the Scandinavian-Mediterranean Corenetwork corridor, of the need for, and if a need is present the optimal design of,complementary governance in the process of sustainable development of a Core networkcorridor.The main findings of the studies are that the implementation process of the Core networkcorridors could benefit from complementary governance measures, mainly to increaseinclusiveness, which is crucial for a sustainable development. Complementary governancecould both deepen and broaden stakeholder awareness and involvement. This may haveseveral advantages, such as increasing possibilities for stakeholders to influence the processand benefit from the corridor, align activities, and promote cooperation and learning betweenstakeholders. Moreover, including stakeholders who are based outside the corridors mayimprove distributive aspects of the investments and reduce risks of focusing attention tooclosely on the corridors per se. However, broadening stakeholder inclusion also hasdisadvantages, as it increases the complexity of the process, which may impair itseffectiveness, and may lead to unrepresentative involvement due to differences instakeholders’ interests, administrative capacities and power. It also increases requirements forcoordination.The nature of complementary governance is multifaceted and related to diverse dimensions ofgovernance, such as processes, stakeholder participation and implementation documents. For complementary governance measures a flexible and task-specific multi-level design isemphasised, which may involve various types of engagement mechanisms. Further, thefindings showed a need to extend previously recognised types of public engagementmechanisms based on communication, consultation and participation in the decision-makingstage, by recognising another category, named stakeholder exchange. This category ischaracterised by stakeholder cooperation and collaboration in an implementation stage wheremain goals and policies already are in place.Areas for complementary governance in the implementation process of the Core networkcorridors were indicated in the interview study. They consisted of extended involvement ofprivate stakeholders, extended involvement of regional and local stakeholders, extendedinvolvement of stakeholders geographically external to the immediate corridor, and extendedinformation both generally and specifically (i.e. directed information to specific stakeholders).Several complementary governance measures that could potentially improve implementationof the Core network corridors were raised in the interviews, ranging from minor adjustment inthe existing process to entirely new solutions. These ideas correspond well to the indicatedareas and provide robust foundations for further discussion.Thus, findings from the research suggest several governance measures to systematicallyinvolve and engage diverse stakeholders in the Core network corridor implementationprocess. However, before introducing such measures, they should be assessed together withexisting governance measures, to avoid overlapping or contradictory initiatives, possiblyusing policy packaging approaches, where policies are combined and analysed together toachieve a desired overall outcome. Proposals for future research and practices are presented.
29

Internationell handel och möjligheter med Cross Trade sändningar : Minska barriärerna med utnyttjandet av Cross Trade

Gidske, Daniel, Sjögren, Linnéa January 2017 (has links)
No description available.
30

Five papers on large scale dynamic discrete choice models of transportation

Blom Västberg, Oskar January 2018 (has links)
Travel demand models have long been used as tools by decision makers and researchers to analyse the effects of policies and infrastructure investments. The purpose of this thesis is to develop a travel demand model which is: sensitive to policies affecting timing of trips and time-space constraints; is consistent with microeconomics; and consistently treats the joint choice of the number of trips to perform during day as well as departure time, destination and mode for all trips. This is achieved using a dynamic discrete choice model (DDCM) of travel demand. The model further allows for a joint treatment of within-day travelling and between-day activity scheduling assuming that individuals are influenced by the past and considers the future when deciding what to do on a certain day. Paper I develops and provides estimation techniques for the daily component of the proposed travel demand model and present simulation results provides within sample validation of the model. Paper II extends the model to allow for correlation in preferences over the course of a day using a mixed-logit specification. Paper III introduces a day-to-day connection by using an infinite horizon DDCM. To allow for estimation of the combined model, Paper III develops conditions under which sequential estimation can be used to estimate very large scale DDCM models in situations where: the discrete state variable is partly latent but transitions are observed; the model repeatedly returns to a small set of states; and between these states there is no discounting, random error terms are i.i.d Gumble and transitions in the discrete state variable is deterministic given a decision. Paper IV develops a dynamic discrete continuous choice model for a household deciding on the number of cars to own, their fuel type and the yearly mileage for each car. It thus contributes to bridging the gap between discrete continuous choice models and DDCMs of car ownership. Infinite horizon DDCMs are commonly found in the literature and are used in, e.g., Paper III and IV in this thesis. It has been well established that the discount factor must be strictly less than one for such models to be well defined.Paper V show that it is possible to extend the framework to discount factors greater than one, allowing DDCM's to describe agents that: maximize the average utility per stage (when there is no discounting); value the future greater than the present and thus prefers improving sequences of outcomes implying that they take high costs early and reach a potential terminal state sooner than optimal. / Modeller för reseefterfrågan har länge använts av besultsfattare såväl somforskare för att analysera effekterna av transportpolitiska åtgärder. Avhandlingenshuvudsakliga syfte har varit att bidra till utvecklandet av modellerför reseefterfrågan som är: känsliga för åtgärder som påverkar tidsvalför resor eller tids-rums begränsningar; och konsistent behandlar valet avantalet resor, avresetid, destination och färdmedel för en individ. Dettauppnås genom användandet av en dynamisk diskret valmodell (DDCM) förreseefterfrågan. Modellen klarar vidare av att gemensamt modellera bådedagligt resande med hänsyn till hur det påverkar behovet av andra resoröver en längre tidshorisont, där individer antas ta hänsyn till både när desenaste utfört olika aktiviteter samt framtida effekter av sina besult. Papper I utvecklar den dagliga komponenten i den föreslagna modellenför reseefterfrågan, presenterar en estimeringsteknik samt resultat från simuleringarmed valideringsresultat. Papper II förbättrar modellen genom attinkludera korrelation i preferenser under dagen med hjälp av en mixed-logitspecifikation. Papper III introducerar en koppling mellan dagar genom enDDCM med oändlig tidshorisont. För att den kombinerade modellen skullevara möjlig att estimera härleddes vilkor under vilka sekvensiell estimeringvar möjlig. Dessa vilkor möjligör därmed estimering av en specific typ avstorskaliga DDCM modeller i situationer när: den diskreta tillståndsvariabelnär delvis latent men där val observeras; där modellen återkommer tillett mindre tillståndrum; och där det mellan återkomsten till detta mindretillståndrum inte sker någon diskontering, nyttofunktionernas feltermer gesav i.i.d Gumble termer och övergångarna mellan disrekta tillståndsvariablerär deterministisk givet valet. Papper IV utvecklar en dynamiskt diskret-kontinuerlig valmodell för etthushålls beslut gällande antalet bilar att äga, deras bränsletyp samt årligamiltal för varje bil. Det därmed till att komibinera dynamiska och diskretkontinulerligavalmodeller för bilägande. DDCM med oändliga tidshorisonter är vanligt förekommande och användsi bland annat Papper III och IV i den här avhandlingen. Det harvarit väl etablerat att diskonteringsfaktorn måste vara strikt mindre än ettför att sådana modeller ska vara väldefinerade. Papper V visar hur det ärmöjligt tillåta diskonteringsfaktorer större än eller lika med ett, och därmedbeskriva agenter som: maximerar den genomsnittliga nyttan per steg (närdet inte sker någon diskontering); värderar framtiden högre än nutiden ochdärmed föredrar förbättrande sekvenser vilket också implicerar att de tarhöga kostnader så tidigt som möjligt och når ett potentiellt sluttillståndtidigare än optimalt.

Page generated in 0.1468 seconds