• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 28
  • 9
  • 7
  • 5
  • 1
  • 1
  • 1
  • Tagged with
  • 53
  • 53
  • 53
  • 22
  • 10
  • 9
  • 9
  • 9
  • 8
  • 8
  • 8
  • 7
  • 7
  • 7
  • 6
  • 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

Asset Management of Electrical Transportation Systems with Life Cycle Cost Analysis for Ground Support Equipment: Case Study Stockholm Arlanda Airport

Wirén, Hampus January 2018 (has links)
We have come a long way in the pursuit of reducing our carbon footprint from our way of living, bycontinuously development of batteries and charging infrastructure for electric vehicles to decrease thedemand for fossil fuels, improving the overall energy efficiency and to increase awareness of the problemto the population. One of the industries, that during the last decades has undergone vast improvements,is the development of the airplane engines due to increased emission regulations, for the aviationindustry, and to reduce the costs of air travel. Despite tighter regulations, global impact from travellingby air is increasing due to the explosive increase in number of travels and travellers. In order to copewith the situation, it is of course necessary to further develop fuel and emission effective airplanes, butalso to study the whole chain of emission sources correlated to the air transport industry. So, whilewaiting for improved airplanes there are well known emission effective technologies that can beimplemented already today – implement electric vehicles as support vehicles at airports.Today, and throughout history, most of the focus of air travel has been on the airplane itself. This thesis,that was carried out at KTH Royal Institute of Technology during late spring and autumn 2018, didinstead study the support vehicles used in airports. In this thesis, a generic economic model wasdeveloped in order to estimate the costs involved when replacing traditionally vehicles to suggestedelectrically propelled alternatives. To test and support the development of an economic model, a casestudy has been carried out at Stockholm Arlanda Airport. This case study included a field study to thementioned airport, and in combination with interviews with former employees from one of the groundhandling companies that are currently active in the airport. Raw data was collected over the equipmentand vehicles currently in use. This data was used to describe the vehicles purpose, requirements and toensure that the alternative electric vehicles proposed would offer at least the same performance as thetraditional vehicles. The developed generic economic model was modulated with five stages thatrepresented a selection of input parameters. The collected data became a result in itself and was used asinput to three concurrent theses.The results from the five stages presents the costs during an investment period of between of one tofifteen years. One of the most significant result could be seen from Stage V. This stage showed that thecombined cost to replace all vehicles currently used, with either all new diesel vehicles or electricalternative vehicles, are lower for electric vehicles than for diesel vehicles. Another significant resultcould be seen from the investigation of Stage IV, Stage IV-B, were the model was modulated to representthe case of replacing a vehicle. The results showed that the Letter and Cargo procedures, that travel thefarthest and has the highest fuel consumption of the investigated vehicles, had negative costs throughthe whole investment period. This means that the expenses will always be lower when these vehicles arereplaced. The model was validated through a sensitivity analysis, performed on the discount rates,depreciation rates and as well as costs for battery replacement during the depreciation period. / Vi har kommit långt i vår strävan att minska vårt koldioxidavtryck genom vårat sätt att leva, genom attkontinuerligt utveckla batterier och laddningsinfrastruktur för elfordon med syftet att minskaefterfrågan på fossila bränslen, förbättra den totala energieffektiviteten och öka befolkningensmedvetenhet om problemet. En av de branscher, som under de senaste decennierna har genomgått storaförbättringar, är utvecklingen av flygplansmotorer och regler för flygplan. Men eftersom antaletflygresenärer fortsätter att öka årligen krävs ytterligare arbete för att förbättra den totala effektivitetenoch minska det negativa globala avtrycket från flygresor. Medan väntan på att morgondagens flygplanska utvecklas så finns det teknik som redan kan appliceras idag – elfordon.I dag, och genom historien, har det mesta av all fokus för flygresor varit på flygplanen själva. Dettaexamensarbete, som genomfördes på KTH, Kungliga Tekniska Högskolan, under den senare delen avvåren och hösten 2018, utredde istället de fordon som omger ett flygplan, under den tid flygplanet stårstilla på en flygplats. Under denna uppsats utvecklades en generisk ekonomiskmodell, med syftet attestimera kostnaderna att ersätta och använda elfordon istället för de nuvarande fordonen. För attutveckla den ekonomiska modellen genomfördes en fallstudie på Stockholm Arlanda Airport.Fallstudien innehöll en fältundersökning till den nämnda flygplatsen, och i kombination med intervjuermed tidigare anställda från ett av de marktjänstföretag som är verksamma på flygplatsen, insamladesrådata om vilken utrustning och fordon som vid tillfället användes. Denna data användes för att beskrivafordonens syfte, vilka krav som ställs på fordonen. Detta var för att säkerställa att det valda elfordonetkunde utföra uppgiften. Den utvecklade generiska ekonomiska modellen modulerades med fem steg,som representerade vilka indataparametrar som bör väljas. De insamlade uppgifterna blev ett resultat isig och användes som indata till tre samtidiga avhandlingar.Den generiska modellen resultat presenterade kostnaderna från de fem stegen under en varierandeinvesteringsperiod på ett till femton år. Ett av de viktigaste resultaten var från Steg V, som visade attden sammanlagda kostnaden för att ersätta alla de fordon som för närvarande används, med antingenalla nya dieselfordon eller elektriska alternativa fordon, är lägre för elfordon än för dieselfordon. Detandra betydande resultatet kommer från undersökningen av Steg IV, Steg IV-B. I Steg IV-B moduleradesmodellen i syfte att representera scenariot då ett fordon ska ersättas, där Letter och Cargo procedurernavar de som färdades längst och även har den högsta bränsleförbrukningen utav de undersökta fordonen,hade en negativ kostnad under hela investeringslängden. Detta betyder att kostnaderna alltid är lägre,om fordonet ersätts. Modellen har validerats med hjälp utav en känslighetsanalys som utfördes pådiskonteringsräntan, avskrivningssatsen och kostnader för ersättningsbatterier.
42

A Total Cost Approach to Supply Chain Risk Modeling

Saunders, Brian J. 08 December 2011 (has links)
The modern supply chain is long, complex, interconnected and global, and plays a fundamental role in business competitiveness. These conditions, along with various supply chain management trends in recent years have increased risks in supply chains which threaten supply chain performance. Greater impact, especially on cost, from an increased threat of supply disruptions is one area of particular concern. Companies today are struggling to find effective means to manage this increased risk and avoid adverse financial impacts. An approach to managing supply disruption risk in supply chains based on the minimization of the total cost of ownership (TCO) of the supply chain is explored in this thesis. Insights are provided into an appropriate view of supply chain risk and a general four step risk management process to guide the design and evaluation of a new risk management tool based on such an approach. A prototype of the new total cost-based, modeling and simulation tool was created in partnership with ProModel Corporation and a government contractor that requested to remain anonymous. A preliminary assessment of the effectiveness of this tool in minimizing TCO and providing an interface useable by non-modelers is provided. This study also reviews and compares a sample set of current supply chain risk management methods and tools and compares them with the new tool for relevance in aiding users in managing supply disruption risk. Based on literature findings and preliminary feedback from pilot contextual demonstrations of the tool, the total cost approach to risk modeling appears promising, although the execution needs to be improved with further enhancements made to the prototype tool. In this preliminary study and evaluation, sufficient evidence is not available to determine that the new prototype tool is any more effective than other currently available risk management tools to provide necessary information to make supply chain risk management decisions that minimize TCO of a supply chain. Suggestions for further development of the tool, especially for improvement of the total cost approach, are provided as well as a preliminary evaluation procedure and survey instruments for a more robust evaluation of the new tool.
43

Technologie cloud computing a virtualizace v podnikové praxi / The cloud computing and virtualization technologies in the enterprise practice

MAURIC, Jakub January 2013 (has links)
This work reports on virtualization and cloud computing technologies. It evaluates their strengths and weaknesses as well as describes the examples of its deployment. The document serves as a concise and comprehensive guide, describing the necessary theory along with the practical use. It is all demonstrated on a real project. The practical part refers to the data environment of the Fire Rescue Service of South Bohemia Region and represents the usage of studied technologies. The analysis also includes project´s financial and technical aspects.
44

Combinations of energy saving measures in pneumatics

Boyko, Vladimir, Weber, Jürgen 26 June 2020 (has links)
Within a production machine, various electromechanical and pneumatic structures can be used for drive tasks. As these drive technologies can often replace each other, the energy efficiency, performance and TCO of pneumatic drives must be permanently enhanced to remain competitive. There is a large number of known measures for the reducing their energy consumption, e.g. minimizing of filling volumes, energy saving circuits etc. However, these measures are mainly considered separately and the possible overall energy saving effect resulting from their combination is rarely taken into account. The main goal of this paper is therefore to explore the possible combinations of pneumatic energy saving measures and their cumulative saving effect. Due to the fact that some measures are mutually exclusive (e.g. a general pressure reduction in properly sized drive), each combination should be considered separately. To evaluate their efficiency plausibly, a comprehensive assessment is required that contains both the total cost of ownership analysis (TCO) and a mechanical properties assessment. The presented comprehensive approach of the task analysis can serve as example of how an optimal drive configuration for the specific task can be found, thus creating a basis for solving constructive challenges in designing of pneumatic automation systems.
45

Factors Influencing the Adoption of Cloud Computing: A Mixed-Methods Approach

Walterbusch, Marc 01 August 2016 (has links)
Cloud computing is a technology that has gained increasing attention because of its considerable benefits, which include reduced costs, reduced complexity and increased flexibility. To obtain these benefits, cloud computing utilizes existing technologies, such as grid computing, virtualization and web services, for online delivery of scalable information technology (IT) services, frequently on the basis of a pay-per-use pricing model. In 2008, the Gartner Group predicted that cloud computing would reach the mainstream within two to five years. However, in their latest hype cycle for emerging technologies, they stated that cloud computing had not yet reached the plateau of productivity but rather was still in the trough of disillusionment. The reason for this situation may be that cloud computing continues to face skepticism because of various concerns regarding, e.g., data privacy and security. In particular, (enterprise) customers transfer (sensitive) data to cloud computing providers, and the end-user rents the right to use cloud computing services via a web browser with minimal need to interact or even without the necessity of interacting directly with a sales assistant. These two aspects result in a strong unilateral dependency and require a high degree of trust in the provider. Additionally, publicity regarding the PRISM program has brought these aspects to the forefront of public interest. Consequently, specific requirements regarding, e.g., security, privacy, accountability, and auditability, must be met to fulfill the expectations of business partners and to build long-term business relationships. Thus, overcoming information asymmetry, enhancing transparency and eradicating behavioral uncertainty is of high importance to build trust between cloud computing providers and their (prospective) customers. Therefore, although most research to date has focused on technical aspects and aimed to improve the actual security of cloud computing services, there is also an urgent need to understand the factors that affect the adoption of cloud computing services from the points of view of both private users and companies. If cloud computing is to reach its full potential, a clear understanding of the factors that influence its adoption is mandatory to improve both present and future cloud computing services. Motivated by these considerations, the aim of this doctoral thesis is to explore, describe, analyze and explain the factors that influence the adoption of cloud computing using various qualitative and quantitative research methods, i.e., by employing a mixed-methods analysis. As a first step, a serious game is conducted to explore various factors that influence the adoption of cloud computing services. Based on these initial findings, the factors explored during the serious game and some additional factors are described and analyzed in detail. These factors include the cloud computing market, costs, trust, affectedness, shadow IT, and sustainability. Furthermore, the factor of information asymmetry, especially regarding bridging the information asymmetry with various information presentation methods, is explained. Following these findings, a research agenda, which contains a recommended research design and lists the theories that are relevant in the context of the adoption of cloud computing, is proposed. Subsequently, a synthesis of the research findings in terms of their implications for practice and research, including limitations, are discussed.
46

The importance of supplier information quality in purchasing of transport services / Betydelsen av leverantörers informationskvalitet vid inköp av transporttjänster

GORDOS, PYGMALION-ALEXANDROS, BULOVAS, JONAS January 2018 (has links)
An important prerequisite for successful supply chain integration is the ability to convert data into information combined with structured storing and sharing processes. The purpose of this master thesis is to investigate potential relation between supplier data quality and performance of purchasing of transport services. The output of the thesis generates evidence about the imperative to emphasize on the supplier data quality throughout the supplier selection process. A supplier data quality assessment framework consisting of 4 dimensions - ease of manipulation, accessibility, accuracy and completeness, is developed as the core product of this research project. The weights of these dimensions were assigned specifically for the case company - Cramo, to determine the quality score for a selected sample of carriers. A coefficient k1 representing the ratio of transport expenditure over sales was introduced to facilitate the identification of relation between supplier data quality and transport expenditure. Business units served by transport companies with higher quality data displayed a lower k1, consequently, paying less for the transport services in comparison to their revenue than business units served by carriers with lower data quality score. The framework developed is adaptable - dimensions and metrics can be added or excluded according to situational factors and case peculiarities. The application of the supplier data quality assessment framework allows for a more objective and streamlined supplier selection. It stresses on the overall costs experienced during the period of cooperation. The finding regarding the importance of supplier data quality in purchasing of transport services can be nonetheless generalized for other cases when companies strive for achieving better informed strategic decisions. / En viktig förutsättning för framgångsrik integration av leverantörskedjor ligger i förmågan att omvandla data till information, kombinerat med en strukturerad lagrings- och delningsprocess. Syftet med denna masteruppsats är att undersöka potentiell relation mellan leverantörers datakvalitet och hur effektivt inköpet av transporttjänsterna är. Utfallet av uppsatsen understryker vikten av att beakta leverantörers datakvalitet i alla delar av en upphandling. Som produkt av denna uppsats har en utvärderingsmall för leverantörers datakvalitet utvecklats. Den består av fyra dimensioner – Hanterbarhet, tillgänglighet, noggrannhet samt fullständighet. De olika dimensionerna är viktade specifikt för det studerade företaget – Cramo, för att fastslå kvalitetsindex för ett urval av deras transportörer. En koefficient - k1- infördes för att representera förhållandet mellan transportkostnad och försäljning. Detta för att underlätta identifieringen av potentiell relation mellan datakvalitet och transportkostnad. Depåer vars transportörer kunde uppvisa en högre datakvalitet hade ett lägre koefficientvärde (k1). Alltså fanns ett samband mellan hög datakvalitet och lägre transportkostnad i förhållande till försäljning. Den utvecklade bedömningsmallen är anpassningsbar – dimensioner och mått kan enkelt adderas eller elimineras utifrån rådande omständigheter i varje fall. Bedömningsmallen ger möjlighet till en mer objektiv och harmoniserad leverantörsbedömning. Mallen understryker även vikten av att beakta den totala kostnaden under avtalstiden. Kunskapen från denna uppsats kring vikten av datakvalitet gällande just transportinköp kan även generaliseras till andra fall där företag strävar mot bättre informerade strategiska beslut.
47

Capital and Operational Cost Evaluation of Selected Powertrain configurations in Heavy-duty Fuel Cell Trucks / Kapital och driftskostnadsutvärdering av utvalda drivlinakonfigurationer i tunga bränslecellstruckar

Vivek Venkatesh, Shenoy January 2021 (has links)
The automotive and heavy-duty trucking industries are heading towards research and development of alternative powertrain solutions to meet the United Nations sustainability goals and cleaner solutions to aid climate change actions. This thesis project aligns with the vision of finding greener and sustainable modes of transport in the heavy long haulage trucking industry. This project aims to find and develop a method for creating drive cycles, getting the vehicular power requirements to drive on these selected routes and finally calculating the TCO of a vehicle. The scripts for these mentioned steps are developed in MATLAB. The approach used in this work could help both the vehicle manufacturer and the vehicle operator to predict or cater to upcoming customer demand on, in our case, routes pan EU, to receive information about energy, power and vehicular configuration needed to fulfil the mission, and also, optimize the powertrain configuration in collaboration with a parallel thesis work done here at Scania, and finally calculate a somewhat simplified TCO of the vehicle.  In this work, two different driving conditions has been used; summer or winter, and two different payload conditions, as well as two types of vehicle powertrains; FCEV and BEV. Finally, a comparison regarding TCO for FCEV and BEV has been done. / Fordonsindustrin, inklusive den kommersiella lastbilsindustrin, driver utvecklingen av alternativa drivlinor för att kunna uppfylla FN:s hållbarhetsmål kring miljövänligare lösningar, nödvändiga för att stödja det globala klimatarbetet. Detta examensarbete utgår från visionen att hitta miljövänligare fordonstyper inom den kommersiella lastbilssektorn. Detta projekt siktar på att utveckla och använda metoder för att kunna ta fram relevanta körcykler, fastställa nödvändig framdrivningseffekt för att fordonen ska kunna köra på utvalda rutter, samt att beräkna total ägandekostnad (TCO) för fordonsoperatören.  Skripten för dessa nämnda steg har utvecklats i MATLAB inom projektet. Tillvägagångssättet som har använts i detta arbete kan hjälpa både fordonstillverkare och fordonsoperatörer att förutspå framtida krav. I vårt fall har information om nödvändig energimängd, effekt och komponentkonfiguration, inklusive drivlineoptimering, tagits fram för rutter inom EU, tillsammans med ett parallellt examensarbete som också utförts på Scania. Slutligen beräknades den totala ägandekostnaden (TCO) för kunden.  I detta arbete har två olika användarfall analyserats; sommar och vinter, för två olika nyttolaster, samt två typer av drivlinor; FCEV och BEV. Slutligen, har en jämförelse gjorts gällande TCO för FCEV och BEV.
48

Policy Tools for the Decarbonisation of Urban Freight Transport in Brazil

Mandana, Raghav Somayya January 2021 (has links)
There has been an increase in the carbon dioxide (CO2) emissions in the last 3 decades. A large share of these emissions is produced by the transport sector. In 2010 alone, global transport accounted for 7 GtCO2 eq and approximately 23% of total energy-related CO2 emissions. In order for the decarbonisation of the transport sector, one of the most important strategies is to reduce the use of fossil fuels. Fossil fuel consumption can be reduced by rolling out more battery electric vehicles (BEVs) on public roads. This is one of the methods by which the concept of electromobility is promoted. In order to increase the share of EVs, many countries have implemented different policies that promote the electrification of the transport sector. With respect to freight transport, electric commercial vans are one of the feasible choices.  This Master thesis involves a quantitative study which focus on the “total cost of ownership” (TCO) of light commercial vehicles (LCVs). Two diesel vans currently used in Curitiba, Brazil were selected - the Sprinter van by Mercedes-Benz and the Master van by Renault. In addition, their electric counterparts were also chosen; in conjunction, a sensitivity analysis with respect to fuel prices and annual distance driven was conducted. The results showed that the TCO of the electric LCVs is around 1.6 to 1.7 times higher than their diesel versions. As far as the two van model types were concerned, the Mercedes-Benz Sprinter had a higher TCO than the Renault Master over the chosen vehicle lifetime for both the diesel and electric versions, with the difference around 7.5% for the diesel versions and approximately 13% for the electric versions.  Based on the results of the TCO study, possible economic policies and fiscal instruments were recommended with regards to light commercial freight transport for Curitiba. / Det har skett en ökning av koldioxidutsläppen (CO2) under de senaste 3 decennierna. En stor del av dessa utsläpp produceras av transportsektorn. Bara 2010 svarade, global transport för 7 GtCO2 ekvivalenter och cirka 23% av de totala energirelaterade koldioxidutsläppen. För att avkolning av transportsektorn är en av de viktigaste strategierna att minska användningen av fossila bränslen. Fossil bränsleförbrukning kan minskas genom att rulla ut fler elektriska fordon (EF) på allmänna vägar när det gäller transportsektorn i allmänhet. Detta är en av metoderna som begreppet elektromobilitet främjas. För att öka andelen elbilar har många länder genomfört olika policyer som främjar elektrifiering av transportsektorn. När det gäller godstransport, är elektriska kommersiella lastbilar och skåpbilar två av de möjliga valen.  Detta examensarbete involverar en kvantitativ studie som fokuserar på “totala ägandekostnaderna” (TÄK) för lätta nyttofordon. Två dieselbilar som för närvarande används i Curitiba, Brasilien valdes - Sprinter-skåpbilen från Mercedes-Benz och Master-skåpbilen av Renault. Dessutom valdes deras elektriska motsvarigheter; i samband med detta genomfördes en känslighetsanalys avseende bränslepriser och årlig körd distans. Resultaten visade att T för elektriska LCV är cirka 1.6 till 1.7 gånger högre än deras dieselversioner. När det gäller de två typerna av skåpbilar hade Mercedes-Benz Sprinter en högre TCO än Renault Master under den valda fordonstiden för både diesel - och elektriska versioner, med skillnaden cirka 7.5% för dieselversionerna och cirka 13% för de elektriska versionerna.  Baserat på resultaten av TCO-studien rekommenderades möjlig ekonomisk politik och finanspolitiska instrument när det gäller lätt kommersiell godstransport för Curitiba.
49

Migration Towards Next Generation Optical Access and Transport Networks

Wang, Kun January 2017 (has links)
By 2020 there will be 50 billion connected devices over the Internet. With the fast-increasing data traffic demand in both fixed and mobile networks, network operators need to migrate networks towards next generation solutions. The network migration requires the enormous investment in equipment and infrastructure, while the revenues are not expected to grow significantly. Therefore, one of the main challenges for network operators is to find out a proper cost-effective optical network solution that can match future high capacity demand and flexibly support multiple network services on a common network infrastructure. The first part of the thesis addresses the Active Optical Network (AON) and its migration strategies towards Next Generation Optical Access (NGOA) solutions. Several migration strategies are proposed from the perspective of network topology, data plane and control plane. A general methodology for Techno-Economic analysis has been developed and applied to the Total Cost of Ownership (TCO) calculation of different NGOA solutions. The thesis provides a complete cost evaluation of AON migration paths, which can be used by network operators to assess the economic feasibility of network migration. A converged Optical Transport Network (OTN) that can serve both fixed and mobile network services is beneficial from the cost-saving perspective. However, the different types of services, require different network performance. The second part of the thesis focuses on the investigation of the converged OTN that can be flexibly and timely adjusted to satisfy varying service conditions. A programmable OTN featured with Wavelength Division Multiplexing (WDM) in the data plane and Software Defined Networking (SDN) in control plane has been proposed. To demonstrate the benefits of the converged OTN, the thesis also provides a multi-domain orchestration architecture for the multiple network services.  The resource orchestration, across three network domains: OTN, mobile network and cloud, enables agile service creation and optimized resource allocation among the multiple domains. / <p>QC 20170512</p>
50

A data management and analytic model for business intelligence applications

Banda, Misheck 05 1900 (has links)
Most organisations use several data management and business intelligence solutions which are on-premise and, or cloud-based to manage and analyse their constantly growing business data. Challenges faced by organisations nowadays include, but are not limited to growth limitations, big data, inadequate analytics, computing, and data storage capabilities. Although these organisations are able to generate reports and dashboards for decision-making in most cases, effective use of their business data and an appropriate business intelligence solution could achieve and retain informed decision-making and allow competitive reaction to the dynamic external environment. A data management and analytic model has been proposed on which organisations could rely for decisive guidance when planning to procure and implement a unified business intelligence solution. To achieve a sound model, literature was reviewed by extensively studying business intelligence in general, and exploring and developing various deployment models and architectures consisting of naïve, on-premise, and cloud-based which revealed their benefits and challenges. The outcome of the literature review was the development of a hybrid business intelligence model and the accompanying architecture as the main contribution to the study.In order to assess the state of business intelligence utilisation, and to validate and improve the proposed architecture, two case studies targeting users and experts were conducted using quantitative and qualitative approaches. The case studies found and established that a decision to procure and implement a successful business intelligence solution is based on a number of crucial elements, such as, applications, devices, tools, business intelligence services, data management and infrastructure. The findings further recognised that the proposed hybrid architecture is the solution for managing complex organisations with serious data challenges. / Computing / M. Sc. (Computing)

Page generated in 0.8474 seconds