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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.
1

Using Improved AHP Method in Maintenance Approach Selection

Rashidpour, Koorosh January 2013 (has links)
This research intends to introduce a model in order to choose the best Maintenance Strategy based on the condition of the relevant company. Basically, it is divided into three main parts. First part is the theoretical part and deals with the Maintenance approaches, conceptions, cost, software, and management. Second part explains the structure of selecting maintenance strategy by using improved Analytical Hierarchical Process (AHP) method and describes some definitions and equations in this scientific method. In the third part, a hypothetical example shows the accuracy of the method and the way it works.
2

Engineering for sustainable development for bio-diesel production

Narayanan, Divya 15 May 2009 (has links)
Engineering for Sustainable Development (ESD) is an integrated systems approach, which aims at developing a balance between the requirements of the current stakeholders without compromising the ability of the future generations to meet their needs. This is a multi-criteria decision-making process that involves the identification of the most optimal sustainable process, which satisfies economic, ecological and social criteria as well as safety and health requirements. Certain difficulties are encountered when ESD is applied, such as ill-defined criteria, scarcity of information, lack of process-specific data, metrics, and the need to satisfy multiple decision makers. To overcome these difficulties, ESD can be broken down into three major steps, starting with the Life Cycle Assessment (LCA) of the process, followed by generation of non-dominating alternatives, and finally selecting the most sustainable process by employing an analytic hierarchical selection process. This methodology starts with the prioritization of the sustainability metrics (health and safety, economic, ecological and social components). The alternatives are then subjected to a pair-wise comparison with respect to each Sustainable Development (SD) indicator and prioritized depending on their performance. The SD indicator priority score and each individual alternative’s performance score together are used to determine the most sustainable alternative. The proposed methodology for ESD is applied for bio-diesel production in this thesis. The results obtained for bio-diesel production using the proposed methodology are similar to the alternatives that are considered to be economically and environmentally favorable by both researchers and commercial manufacturers; hence the proposed methodology can be considered to be accurate. The proposed methodology will also find wide range of application as it is flexible and can be used for the sustainable development of a number of systems similar to the bio-diesel production system; it is also user friendly and can be customized with ease. Due to these benefits, the proposed methodology can be considered to be a useful tool for decision making for sustainable development of chemical processes.
3

A design strategy for reconfigurable manufacturing systems (RMSs) using the analytical hierarchical process (AHP): A case study.

Abdi, M. Reza, Labib, A.W. January 2003 (has links)
No / This paper presents Reconfigurable Manufacturing System (RMS) characteristics through comparison with conventional manufacturing systems in order to address a design strategy towards a RMS. The strategy is considered as apart of a RMS design loop to achieve a reconfigurable strategy over its implementation period. As another part of the design loop, a reconfiguration link between market and manufacturing is presented in order to group products into families (reconfiguring products) and then assign them to the required manufacturing processes over configuration stages. In particular, the Analytical Hierarchical Process (AHP) is employed for structuring the decision making process for the selection of a manufacturing system among feasible alternatives based on the RMS study. Manufacturing responsiveness is considered as the ability of using existing resources to reflect new environmental and technological changes quickly. The AHP model highlights manufacturing responsiveness as a new economic objective along with classical objectives such as low cost and high quality. The forward-backward process is then proposed to direct and control the design strategy under uncertain conditions during its implementation period. The proposed hierarchy is generic in structure and could be applicable to many firms by means of restructuring the criteria. This work is based on a case study in a manufacturing environment. Expert Choice software (Expert Choice 1999) is applied to examine the structure of the proposed model and achieve synthesise/ graphical results considering inconsistency ratios. The results are examined by monitoring sensitivity analysis while changing the criteria priorities. Finally, to allocate available resources to the alternative solutions, a (0-1) knapsack formulation algorithm is represented.
4

Gis-based Microzontion Of Niksar (tokat) Settlement Area For The Purpose Of The Urban Planning

Erol, Gokhan 01 December 2009 (has links) (PDF)
Niksar (Tokat), is an urban area located in a seismically active zone of Turkey. The aim of this thesis is to prepare GIS-based microzonation map of Niksar settlement area for the purpose of urban planning. Liquefaction, activity, slope, aspect, fault proximity, ground amplification and lithology are considered during the overlay analysis by using Multicriteria Decision Making Analysis (MCDA) of Simple Additive Weighing (SAW) and Analytical Hierarchical Process (AHP) methods. Based on the evaluations, the study area is divided into four different zones, namely, (1) areas suitable for settlement / (2) provisional settlement areas / (3) areas requiring detailed geotechnical investigation / (4) unsuitable areas. Two microzonation maps obtained from analyses are compared. Maps prepared by SAW and AHP methods are found to be consistent with each other. However, the microzonation map prepared by AHP method is recommended for the purpose of urban planning because it has the ability to check consistency itself.
5

Two Issues in Premise Plumbing: Contamination Intrusion at Service Line and Choosing Alternative Plumbing Material

Lee, Juneseok 01 May 2008 (has links)
Worldwide water distribution infrastructure system is old and deteriorating. A water system with its myriad appurtenances (including pumps and valves and tanks) is susceptible to hydraulic transients resulting in high and low pressure waves alternatively passing through the network. While both low and high pressure events structurally tax the already weak system, there is copious evidence indicating intrusion of contaminants into the drinking water pipes from the pipe's exterior environment due to low pressure events associated with water hammer phenomenon. These contaminants enter into the drinking water as the home plumbing system is a passive recipient from the water main. While the major (municipal) system is readily recognized as a vast infrastructure system of nearly 1,409,800 km of piping within the United States, the minor (plumbing) system that is at least 5 to 10 times larger is generally not well analyzed. In this study, an experimental plumbing rig was designed and implemented that replicates the range of pressures encountered in actual minor water distribution systems. This research addresses how a pressure transient triggered within a house and from municipal systems can impact the service line with a possible suction effect. Experimental results on low pressure events and the accompanying numerical modeling showed good agreement. The experiment also enabled visualization of the various pressure transient phenomena. It is demonstrated that hydraulic transients triggered from water mains result in low pressures events (up to -10 psig) in service lines which can allow possible intrusion of microbial and chemical contaminants at the service line. Structural integrity of service line and hydraulic integrity at water mains should be maintained to minimize any public health risks. In the USA, about 90% of residential drinking water plumbing systems use copper pipes. Pinhole leaks in copper plumbing pipes have become a nationwide concern because these leaks cause property damage, lower property values, and result in possibility of adversely affecting homeowners' insurance coverage. In addition, resulting mold damage may cause health concerns. This research also addresses the concerns of the affected homeowners by enabling them to decide on whether to continue to repair or replace their plumbing system, the factors to be considered in a replacement decision, and the type of material to use for replacement. Plastic pipes such as PEX (cross-linked polyethylene), CPVC (Chlorinated Polyvinyl Chloride), and copper are considered in present analysis. Other alternatives include an epoxy coating technique on the existing piping systems, without the need to tear into walls. Multiple attributes of a plumbing system including cost (material plus labor charges), taste and odor impacts, potential for corrosion, longevity of the pipe system, fire retardance, convenience of installation or replacement, plumber or general contractor's opinions or expertise, and proven record in the market are considered. Attributes and material rankings are formalized within the framework of the preference elicitation tools namely AHP (Analytical Hierarchical Process). Surveys are conducted with selected homeowners in pinhole leak prone area in Southeastern US Community to observe their revealed and stated preferences. Participants' overall preference tradeoffs are reported in addition to comparing their revealed and stated preferences. Health effects, taste and odor of water turned out to be the most important factors from the survey. In real life, however, homeowners were not well aware of these safety issues related with plumbing materials. It is recommended that water professionals should work on bridging the gap between public perception and research results related to major and minor systems. / Ph. D.
6

Geographical Information Systems Based Microzonation Map Of Eskisehir Downtown Area

Kolat, Cagil 01 September 2004 (has links) (PDF)
The purpose of this study is to prepare a geotechnical microzonation map regarding the suitability of the residential areas in EskiSehir downtown area. In order to obtain the microzonation map, Geographical Information Systems (GIS) based Multicriteria Decision Analysis (MCDA) is used. For this analysis, the slope, flood susceptibility, soil, depth to groundwater table, swelling potential and liquefaction potential layers are prepared. The weight values to the layers and rank values to the classes of each layer are assigned by applying Simple Additive Weighting (SAW) and Analytical Hierarchical Process (AHP) methods. Two geotechnical microzonation maps are obtained as outputs of these methods. The study area is categorized into three different zones regarding the foundation suitability of residential areas as: (1) Areas suitable for settlement / (2) Provisional settlement areas / (3) Areas requiring detailed geotechnical investigations. The maps prepared using SAW and AHP methods are found to be consistent with each other. The geotechnical microzonation map prepared using AHP method is recommended as the final map of the study area.
7

An Expert-based Approach for Grid Peak Demand Curtailment using HVAC Thermostat Setpoint Interventions in Commercial Buildings

Ramdaspalli, Sneha Raj 01 July 2021 (has links)
This dissertation explores the idea of inducing grid peak demand curtailment by turning commercial buildings into interactive assets for building owners during the demand control period. The work presented here is useful for both ab initio design of new sites and for existing or retrofitted sites. An analytical hierarchy process (AHP)-based framework is developed to curtail the thermal load effectively across a group of commercial buildings. It gives an insight into the amount of peak demand reduction possible for each building, subject to indoor thermal comfort constraints as per ASHRAE standards. Furthermore, the detailed operation of buildings in communion with the electric grid is illustrated through case studies. This analysis forms an outline for the assessment of transactive energy opportunities for commercial buildings in distribution system operations and lays the foundation for a seamless building-to-grid integration framework. The contribution of this dissertation is fourfold – (a) an efficient method of developing high-fidelity physics-based building energy models for understanding the realistic operation of commercial buildings, (b) identification of minimal dataset to achieve a target accuracy for the building energy models (c) quantification of building peak demand reduction potential and corresponding energy savings across a stipulated range of thermostat setpoint temperatures and (d) AHP-based demand curtailment scheme. By careful modeling, it is shown that commercial building models developed using this methodology are both accurate and robust. As a result, the proposed approach can be extended to other commercial buildings of diverse characteristics, independent of the location. The methodology presented here takes a holistic approach towards building energy modeling by accounting for several building parameters and interactions between them. In addition, parametric analysis is done to identify a useful minimal dataset required to achieve a specified accuracy for the building energy models. This thesis describes the concept of commercial buildings as interactive assets in a transactive grid environment and the idea behind its working. / Doctor of Philosophy / This dissertation titled "An Expert-based Approach for Grid Peak Demand Curtailment using HVAC Thermostat Setpoint Interventions in Commercial Buildings" tackles two important challenges in the energy management domain: –electric grid peak demand curtailment and energy savings in commercial buildings. The distinguishing feature of the proposed solution lies in addressing these challenges solely through demand-side management (DSM) strategies, which include HVAC thermostat setpoint interventions and lighting control. We present a methodology for developing highly accurate building energy models that serve as digital twins of actual buildings. These digital replicas can be used to quantify the impact of various interventions and reflect the realistic operation of commercial buildings across varied conditions. This enables building owners to control demand intelligently and transact energy effectively in the electricity market. The development of Internet of Things (IoT) market and advanced technologies such as smart meters and smart thermostats allows for the design of novel strategies that address traditional challenges faced by electric grid operators. This dissertation elaborates on how smart buildings can leverage IoT-based solutions to participate in the electricity market during demand control periods. We also developed an expert opinion-based demand curtailment allocation scheme resulting in grid peak demand reduction. The numerical results obtained reinforce the effectiveness of the proposed solution across varied climatic conditions.
8

A performance measurement model for a service partnership

Lategan, Jacobus Petrus 03 1900 (has links)
Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The problem with which many organisations struggle in the current economical environment is that of focus. They are trapped in a situation where limited resources or lack of inherent knowledge withhold them from increasing shareholder value. This research focuses on the strategy which an organisation pursues when outsourcing those business functions which are outside their core competencies. The outcome of this decision involves them entering into a partnership with a service organisation (or consultancy). The duration of the relationship between these parties is dependent on the value (actual plus perceived) which the service organisation contributes to its customer. Pragma (a service organisation in the physical asset management (PAM) environment) is, due to the current economic turmoil, in a situation where they need to indicate the value created through the acquirement of their service. This leads to a search for a model which would provide them with the required justification. A study was conducted on current available frameworks but none of those identified suited this type of measurement. This led to the development of a unique model (based on the principles of the Balanced Scorecard) called the performance measurement value index (PMVI) which identifies the generic elements required to measure the value of a service partnership. These elements are: 1. financial perspective; 2. customer engagement; 3. risk management; and 4. internal business processes. These elements are weighted (using the analytical hierarchical process) to represent the change in value, as contributed by the elements, and is then represented as a single value (ten is used as this arbitrary value in this research). The PMVI is introduced into the PAM environment which then produces the asset management value index (AMVI). The four elements of the PMVI are broken down into five elements required for the AMVI. These elements are: 1. cost reduction; 2. asset performance improvement; 3. customer satisfaction; 4. risk reduction; and 5. asset management maturity. The model was applied to three of Pragma’s customers. The type of application (within this environment) is dependent on the nature of both the customer and service. The first two customers are both from a manufacturing environment but they differ in the type of service (ACC@Pragma vs ACC@Client) rendered. The third customer operates within the utilities and facilities environment and receives an ACC@Client service. The period over which the model was applied varies due to the use and availability of historical data of these customers. An increase in value was noted for the two ACC@Client customers (from 7.68 to 8.51 and 4.54 to 7.73 respectively), where the service partnership is still in its early stages (one to three years old). However, the ACC@Pragma customer reflected a stagnating value (6.62 to 6.59) where the service partnership is older than ten years. These results reflect the expectations which Pragma had at the beginning of the study and consequently proves that they do add value to their customers. / AFRIKAANSE OPSOMMING: Die huidige ekonomiese omgewing veroorsaak dat baie ondernemings sukkel om te fokus. Hulle word vasgevang in ‘n situasie waar ‘n beperking in hulpbronne of ‘n tekort aan nodige kennis hulle verhoed om waarde te verskaf aan hulle aandeelhouers. Hierdie navorsing ondersoek daardie strategie van ‘n onderneming wat daartoe lei dat hulle sekere besigheids funksies, wat hulle nie beskou as hul eie sterktepunte nie, uitkontrakteer en gevolglik kan fokus op hul sterktepunte. Die gevolg van hierdie besluit verg dat die onderneming ‘n ooreenkoms aangaan met ‘n dienste onderneming. Die tydperk van hierdie verhouding word bepaal deur die waarde (beide werklik en aangevoelde) wat die dienste onderneming toevoeg tot hul klient. Pragma (‘n dienste onderneming in die fisiese bates bestuur bedryf) word huidiglik gekonfronteer met die situasie waar hulle die waarde wat, weens die lewering van hul diens, toegevoeg word tot die klient. Dit lei tot die soeke na ‘n model om die lewering van hulle diens te valideer. ‘n Studie was uitgevoer op die huidige beskikbare modele wat doeltreffendheid in ‘n onderneming meet, maar geen van die geїdentifiseerdes was toepaslik op hiersie situasie nie. Dit het gelei tot die ontwikkeling van ‘n unieke model (gebaseer op die beginsels van die Balanced Scorecard) genaamd die Performance Measurement Value Index (PMVI) wat die nodige elemente vir die meting van hierdie tipe doeltreffenheid identifiseer. Hierdie elemente sluit in die: • finansiële perspektief; • kliënte interaksie; • risiko bestuur; en • interne besigheids prosesse. Die geweegde uikomste van hierdie elemente (soos bepaal deur die Analytical Hierarchical Process) word gebruik om ‘n verandering in waarde aan te dui as ‘n enkele waarde (tien in die geval van hierdie studie).Die PMVI word aangepas vir gebruik in die fisiese bate bestuur omgewing en die gevolge hiervan is die skepping van die Asset Management Value Index (AMVI). Die vier elemente, soos gebruik in die PMVI, word aangepas na vyf elemente in die AMVI. Hierdie elemente sluit in die: • verlaging van uitgawes; • bate doeltreffenheid verhoging; • kliënt tevredenheid; • risiko verlaging; en • bate bestuur verbetering (verbetering in die interne besigheids funksies van bate bestuur). Die model was toegepas op drie van Pragma se kliente. Die tipe van toepassing (binne hierdie omgewing) is afhanklik van beide die kliënt en dienste gelewer. Die eerste twee kliënte is beide afkomstig van ‘n hoofsaaklik vervaardigings-omgewing, maar die dienste gelewer aan die kliënte verskil (ACC@Pragma vs ACC@Client). Die ander klient is afkomstig vanuit ‘n dienste en geboue omgewing en ontvang die dienste van ‘n ACC@Client. Die tydperk waaroor die AMVI toegepas is verskil weens die toepaslikheid en beskikbaarheid van historiese inligting. ‘n Toename in waarde is bevind by beide van die ACC@Client kliënte (vanaf 7.68 na 8.51 en 4.54 na 7.73 onderskeidelik). Dit kan toeskryf word aan die vroeë fase waarin hierdie diens ooreenkoms funksioneer (vanaf een tot drie jaar). Die uitkomste van die ACC@Pragma, aan die anderkant, dui op stagnerende waarde (6.62 na 6.59) vir die kliënt waar die diens ooreenkoms alreeds ouer as tien jaar is. Die uitkomste van hierdie studie bewys die verwagtinge wat Pragma aan die begin van hierdie studie gehad het en bewys gevolglik dat hulle wel waarde toevoeg tot hul kliënte.
9

Framtagning av bedömningsmall av produktleverantörer i stålbyggnadsbranschen : Fallstudie på Llentab AB

Karakas, Berhan, Stempnik, Aleksandra January 2017 (has links)
Inköp och leverantörsval påverkar företags konkurrenskraftighet. För att behålla sin position på marknaden och skapa långsiktiga relationer måste företag välja rätt partnerföretag. Företag kan uppnå sitt mål med leverantörsrelationer med hjälp av begränsat antal samarbetspartner, rätt bedömning och segmentering av leverantörer. Inköpsprocess och bedömningsmetod studerades på ett fallföretag för att erhålla information om ett nuvarande läge som sedan med hjälp av teori kunde operationaliseras och analyseras. Detta görs i huvudsak med hjälp av Multi-Criteria Decision Making, Kraljic matris och inköpspolicy. Resultatet presenterades med hjälp av sex leverantörer. För att leverantörerna ska vara godtagbar skall alla ‘obligatoriska’ krav uppfyllas i inköpspolicyn och erhålla ett önskat läge i Kraljic matris. Nyckelord: Kraljic matris, leverantörsbedömning, standardiserad bedömningsmall, inköpsprocess, Multi-Criteria Decision Making, Analytical Hierarchical Process, BFP-Bedömningsmall för produktleverantörer.
10

Adaptive Water Management Concepts: Principles and Applications for Sustainable Development

Edalat, F.D., Abdi, M. Reza January 2017 (has links)
No / his book explores a new framework of Adaptive Water Management (AWM) for evaluating existing approaches in urban water management. It highlights the need to adopt multidisciplinary strategies in water management while providing an in-depth understanding of institutional interactions amongst different water related sectors. The key characteristics of AWM i.e. polycentric governance, organisational flexibility and public participation are investigated and described through a critical review of the relevant literature. The book presents an empirical case study undertaken in a selected developing-country city to investigate the potential gaps between the current water management approaches and possible implementation of AWM. Feasibility of AWM operations is examined in an environment surrounded by established water management structure with centralised governance and an institutional process based on technical flexibility. The key elements of AWM performance are (re)structured and transformed into decision support systems. Multi criteria decision models are developed to facilitate quantification and visualization of the elements derived from the case study, which is involved with water companies and water consumers. The book describes how the concept of AWM, along with structuring suitable decision support systems, can be developed and applied to developing-country cities. The book highlights the barriers for applying the AWM strategies that include established centralised decision making, bureaucratic interactions with external organisations, lack of organisational flexibility within the institutions, and lack of recognition of public role in water management. The findings outline that despite the lack of adaptability in the current water management in the case study, as an example of developing countries, there are positive attitudes among water professionals and the public towards adaptability through public-institutional participation.

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