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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

Implications of the pressure dependency of outflows of data management, mathematical modelling and reliability assessment of water distribution systems

Tabesh, Massoud January 1998 (has links)
No description available.
2

The interrelationship between suppliers and the Hub organisation within supply networks

Aina, Maria Oluwatoyin January 2016 (has links)
This thesis presents a further study on Dai and Zhang’s (2008) supply networks, which are Cost Saver, Adapter, and Multiple Driven. This concept is centred on hub or focal firm which is the core of the supply networks, built on Miles and Snow’s (2003) strategic typology. In Cost Saver supply network, the hub firm is ‘Defender’; for Adapter supply network it is ‘Prospector’, while in Multiple Driven supply network it is ‘Analyser’. This study explores the interrelationship between the hub and supplier’s configuration and its effect on organisational performance. A comprehensive literature review is carried out with reference to supply chain (SC), supply network (SN) and supply network management (SNM). It stretches to describing Dai and Zhang’s (2008) novel supply networks, its association with Miles and Snow’s theory, the supply network configuration concept, and further expatiates on the need for appropriate supplier configuration for improved performances within the supply networks. The key performance indicators (KPI) adopted for this work, the variables considered in the simulation modelling were evaluated. Usable data were collected from a sample of 630 suppliers, and 15 hub firms. This is accompanied by Hypotheses testing, Case study and Simulation experiments to fulfil the aims and objectives of this research. From the findings of this study, it is confirmed that organisations can be grouped as either the Defender, Prospector, Analyser or Reactor type according to the Miles and Snow typology. The investigation identified that for Multiple Driven, Adapter and Cost Saver supply networks, performances are most improved with an increase in the existence of suppliers of the same typology with the hub organisation within the supply network.
3

Developing low carbon supply networks : influence, measurement, and improvement

Hu, Jialun January 2018 (has links)
Climate change has emerged as one of the most serious challenges faced by human beings. As manufacturing globalisation involves more and more emerging nations, a greater proportion of CO2 emissions is generated from developing countries. The dilemma between fast industrial development and carbon reduction makes firms in developing nations reluctant to take serious commitment and actions in CO2 emission reduction in their global manufacturing practices. From a theoretical perspective, low-carbon supply networks research is also still in its infant stage and needs more explorations and development. Therefore this research aims to address the research question: “How can supply networks in developing countries be developed to reduce carbon emission?” Especially it focuses on: • An influence process to engage companies in developing countries to reduce carbon emission • A typology of carbon emission assessments in supply networks • An initial process of implementing carbon-reduction projects in supply network The research adopts theory building approach based on multiple case studies. The units of analysis are carbon reduction project of focal firms and initiatives of Non-Government Organizations (NGO). Drawing upon the cases, this research develops a general framework for developing low-carbon supply network, including three parts namely network influence, network CO2 measurement, and network CO2 improvement (IMI), with the three process models accordingly proposed. In the ‘influence’ process, based on resource dependence theory (RDT), this research illustrates a categorization of influence choices and a typology of influence pathways, which both underpin the four-step influence procedure proposed later. In the ‘measurement’ process, this research proposes a goal-oriented carbon footprint measurement guideline. In the “improvement’ process, an initial framework to classify carbon reduction projects and implementation process model of these projects are both built based on the analysis of primary case studies and Carbon Disclosure Project (CDP) database which contains corporates’ carbon reduction practices. Overall this research makes contributions in the following aspects: (1) this research advocates IMI framework as a pathway to de-carbonize supply networks, contributing to manufacturing system’s evolution to sustainable paradigm; (2) It integrates the institutional, stakeholder and network theory in the context of de-carbonization, and extends the research scope of operations management; (3) The research contributes to life cycle assessment (LCA) literature by exploring supply network coordination during the LCA procedure; (4) The research also contributes to green supply chain literature by providing insights from firms’ de-carbonization projects in supply network. (5) In practice, the IMI three-process models can help practitioners to implement de-carbonization management, serving as a preliminary guideline to follow. The potential audience of this research can be MNCs, NGOs, government bodies, consultants, and any organization or individual who aim to change industrial system in the pursuit of climate change mitigation.
4

Exploring the Relationship between Supply Network Configuration, Interorganizational Information Sharing and Performance

Daley, Marcia 09 January 2009 (has links)
ABSTRACT EXPLORING THE RELATIONSHIP BETWEEN SUPPLY NETWORK CONFIGURATION, INTER-ORGANIZATIONAL INFORMATION SHARING AND PERFORMANCE By MARCIA DALEY August 2008 Committee Chair: Dr. Subhashish Samaddar Major Department: Decision Science Critical to the success of a firm is the ability of managers to coordinate the complex network of business relationships that can exist between business partners in the supply network. However many managers are unsure on how best to leverage their resources to capitalize on the information sharing opportunities that are available in such networks. Although there is significant research on information sharing, the area of inter-organizational information sharing (IIS) is still evolving and there is limited research on IIS in relation to systemic factors within supply networks. To help fill this gap in the literature, a primary focus of this dissertation is on the relationship between the design of the supply network and IIS. The design of the supply network is characterized by the supply network configuration which is comprised of (1) the network pattern, (2) the number of stages in the supply network, and (3) where the firm is located in that supply network. Four different types of IIS are investigated, herein. These types of IIS are a function of the frequency with which information is shared and the scope of information shared. Type 1 (Type 2) IIS is the low (high) frequency state where only operational information is shared. Similarly, Type 3 (Type 4) is the low (high) frequency state where strategic information is shared. The argument is that the type of IIS varies depending on the configuration of the supply network and that this relationship is influenced by the coordination structure established between firms in the network. The second focus of this dissertation deals with the relationship between IIS and performance. Research findings on the benefits to be gained from IIS have been ambiguous, with some researchers claiming reduced cost in the supply network with IIS, and others finding minimal or no benefits. To add clarity to these findings, the role that uncertainty plays in the relationship between IIS and performance is examined. The thesis presented is that the positive relationship between IIS types and the performance of the supply network is impacted by process uncertainty (i.e. the variability in process outcomes and production times), and partner uncertainty. Social network theory and transaction cost economics provide the theoretical lens for this dissertation. A model is developed and will be empirically validated in a cross-sectional setting, utilizing a sampling frame randomly selected and comprised of supply management executives from various industries within the United States.
5

Kvalitetsgranskning av flödesdata från vattenledningsnätet / Quality control of flow meter data from water supply networks

Eliasson, Victor January 2016 (has links)
In an attempt to revise the guidelines which are the basis of today’s design of water and sewage systems, Tyréns carries out a project for Swedish Water & Wastewater Association (SWWA). This SWWA project aims to, based on flow meter data, map out the behavior pattern regarding water consumption for certain types of consumers, such as industrial or individual users. The overall goal is to get a better support for the dimensioning process. A prerequisite for SWWA study is that the data to be analyzed are of good quality. Therefore this thesis will be included as a sub-study for the SWWA project with the goal to find and test methods for quality control of the flow meter data. This thesis showed some methods to statistically validate the data. A method is for instance presented that is used to detect changes in the statistical distribution for the sets of flow meter data. The changes that were studied were either changes in mean or variance. The latter turned out to be able to detect sequences, mostly during the summer, when the daily variations in water demand is different than during the rest of the year. Furthermore, some outliers could be identified using regression analysis. Some measurement errors, such as repeated flow values, could also be detected using run length encoding. In identifying anomalies and outliers, some types of those were possible to explain as false flow observation or non-representative for the data series as a whole for further analysis in the SWWA project. Other suspected observations were not possible to declare as true erroneous and have therefore been flagged for further investigation with support by an expert in the field. / I ett försök att revidera de riktlinjer som ligger till grund för dagens dimensionering av vatten- och avloppsledningsnät, genomför Tyréns ett projekt för Svenskt Vatten Utveckling (SVU). Detta SVU-projekt syftar till att utifrån flödesdata från vattenledningsnätet kartlägga beteendemönster hos olika förbrukartypers vattenförbrukning, såsom storförbrukare och enskilda brukare, för att på så vis kunna erhålla bättre och mer aktuella underlag för dimensioneringen. En förutsättning för SVU-studien är att det mätdata som ska analyseras håller god kvalitet. Därför kommer detta examensarbete att ingå som en understudie till SVU-projektet med syftet att finna en metod för att kvalitetsgranska flödesdata. Detta examensarbete visade metoder för att statistiskt granska flödesdatat med avseende på outliers och anomalier. Bland annat presenterades en metod för att finna förändringar i mätseriernas statistiska fördelning. De förändringar som studerades var antingen förändring av medelvärde eller en förändring av variansen. Den senare visade sig kunna detektera sekvenser, framförallt under sommaren, där dygnsvariationen i vattenförbrukningen ofta var annorlunda mot resten av året. Vidare kunde outliers detekteras med hjälp av regressionsanalyser på mätserierna.  Olika mätfel, exempelvis mätvärden som upprepas, kunde även identifieras med hjälp av skurlängdskodning. Vid identifiering av anomalier eller outliers har vissa typer kunnat detekteras och förklarats som felaktiga värden eller icke representativa för mätserien för vidare analyser. Andra identifierade suspekta mätvärden har inte kunnat förklaras eller det har inte kunnat säkerställas att de är felaktiga. Dessa har markerats och bör studeras av en expert inom ämnesområdet.
6

Modeling influence diffusion in networks for community detection, resilience analysis and viral marketing

Wang, Wenjun 01 August 2016 (has links)
The past decades have seen a fast-growing and dynamic trend of network science and its applications. From the Internet to Facebook, from telecommunications to power grids, from protein interactions to paper citations, networks are everywhere and the network paradigm is pervasive. Network analysis and mining has become an important tool for scientific research and industrial applications to diverse domains. For example, finding communities within social networks enables us to identify groups of densely connected customers who may share similar interests and behaviors and thus generate more effective recommender systems; investigating the supply-network topological structure and growth model improves the resilience of supply networks against disruptions; and modeling influence diffusion in social networks provides insights into viral marketing strategies. However, none of these tasks is trivial. In fact, community detection, resilience analysis, and influence-diffusion modeling are all important challenges in complex networks. My PhD research contributes to these endeavors by exploring the implicit knowledge of connectivity and proximity encoded in the network graph topology. Our research originated from an attempt to find communities in networks. After carefully examining real-life communities and the features and limitations of a set of widely-used centrality measures, we develop a simple but powerful reachability-based influence-diffusion model. Based upon this model, we propose a new influence centrality and a novel shared-influence-neighbor (SIN) similarity. The former differentiates the comprehensive influence significance more precisely, and the latter gives rise to a refined vertex-pair closeness metric. Then we develop an influence-guided spherical K-means (IGSK) algorithm for community detection. Further, we propose two novel influence-guided label propagation (IGLP) algorithms for finding hierarchical communities in complex networks. Experiments on both real-life networks and synthetic benchmarks demonstrate superior performance of our algorithms in both undirected/directed and unweighted/weighted networks. Another research topic we investigated is resilience analysis of supply networks. Supply networks play an important role in product distribution, and survivability is a critical concern in supply-network design and analysis. We exploit the resilience embedded in supply-network topology by exploring the multiple-path reachability of each demand node to other nodes, and propose a novel resilience metric. We also develop new supply-network growth mechanisms that reflect the heterogeneous roles of different types of units in supply networks. We incorporate them into two fundamental network topologies (random-graph topology and scale-free topology), and evaluate the resilience under random disruptions and targeted attacks using the new resilience metric. The experimental results verify the validity of our resilience metric and the effectiveness of our growth model. This research provides a generic framework and important insights into the construction of robust supply networks. Finally, we investigate activation-based influence-diffusion modeling for viral marketing. One of the fundamental problems in viral marketing is to find a small set of initial adopters who can trigger the largest further adoptions through word-of-mouth-based influence propagation in the network. We propose a novel multiple-path asynchronous threshold (MAT) model, in which we quantitatively measure influence and keep track of its diffusion and aggregation during the diffusion process. Our MAT model captures both direct and indirect influence, influence attenuation along diffusion paths, temporal influence decay, and individual diffusion dynamics. Our work is an important step toward a more realistic diffusion model. Further, we develop two effective and efficient heuristics (IV-Greedy and IV-Community) to tackle the influence-maximization problem. Our experiments on four real-life networks demonstrate their excellent performance in terms of both influence spread and efficiency. Our work provides preliminary but significant insights and implications for diffusion research and marketing practice.
7

Factors influencing phytoplankton composition in Wingecarribee and Fitzroy Falls Reservoirs

Furler, Wayne, n/a January 1990 (has links)
Wingecarribee and Fitzroy Falls Reservoirs are part of the Shoalhaven system within the Sydney metropolitan water supply network and are both shallow, well mixed, polymictic water bodies. After construction in 1973, land use activities within the catchments changed from low intensity grazing to more intensive practices such as dairying, particularly on the northern foreshore of Wingecarribee Reservoir, and vegetable farming around Fitzroy Falls Reservoir. The change in land use practice raised concerns about the possible impact on water quality of the reservoirs. This study sought to differentiate between the influence of catchment effects, inter-reservoir transfers and seasonality to enable an assessment of long term trends in water quality to be made. Data collected on a monthly basis by the Water Board between October 1973 and December 1985 were assessed and representative or 'indicator' variables for the different influences were selected. Classification of the phytoplankton to create sample clusters followed by discriminant analysis of the abiotic data were performed to rank the 'indicator' variables The classification analyses indicated that time of sampling was more important than site differences in determining clustering and that both Wingecarribee and Fitzroy Falls Reservoirs were well mixed and similar. The influence of chronological changes following the initial filling of the reservoirs, seasonality and inter-reservoir transfers were detected in the clustering patterns. Changes attributable to land use activities within the catchments were not detected. The reduction in concentrations of variables from high values following the initial filling of the reservoirs was the main influence regulating clustering between 1974 to 1982 and the influence of seasonality on clustering was most apparent during 1976 and 1978. The assessment of the influence of inter-reservoir transfers was restricted because of limited data. Seasonal periodicities and ongoing changes in the phytoplankton and physical and chemical data over the study period were assessed as a means of interpreting and verifying the analysis results.
8

Hydraulická analýza vodovodní sítě obce Ostopovice / Hydraulic analysis of the water supply network of the municipality of Ostopovice

Jaroš, Zdeněk January 2021 (has links)
The theses focuses on a hydraulic analysis of a water supply network of a village called Ostopovice, located in South Moravia. Theses presents a detailed quasi-dynamic hydraulic simulation of the water supply network based on own consumer field survey. Subsequently, the assembled model was calibrated and verified by hydraulic data measured on the water supply network. The model was made to simulate characteristic water supply system operating conditions. Using the hydraulic analysis results, the theses assesses network pressure conditions with regards to the existing building range and type, taking into the account the extent of expected house development of the area. The work concludes with a proposition for measures leading to the water supply network pressure conditions optimization.
9

Supply network configuration for small series, high-cost production : Exploring the European textile and apparel industry context

Harper, Sara January 2020 (has links)
The purpose of this thesis is to increase the understanding of supply network configuration (SNC) for small series production in high-cost contexts in relation to the textile/apparel industry. SNC encompasses strategic structural and infrastructural decisions at the supply chain level, motivated by capabilities/priorities. The key configuration decisions addressed concern textile/apparel production in Europe, with associated context-specific advantages and challenges. The thesis takes a particular focus on how practitioners consider these configurations and motivations. The thesis begins with identification of motivations for locating textile/apparel production in high-cost contexts, to capture the driving priorities. Thereafter, the thesis extends the focus beyond location motivations to identify the key SNC aspects and characteristics for small series production in high-cost contexts. These configuration-related aspects and capabilities are elaborated upon and modelled to understand how they are interrelated in textile/apparel industry contexts. The empirical work uses mixed-methods and seeks to bring together the relevant topics using a SNC and capabilities approach. The specific methods, Delphi study and interpretive structural modeling, are focused on sensitivity practitioner perspectives. Findings show multiple key motivations/capabilities for high-cost textile/apparel production, specifically small series production (customization); which is closely linked with several other priorities, including quality and flexibility/delivery. Expanding the view to the SNC aspects, the findings confirm and extend the literature regarding complexities, multi-level characteristics, synergies and trade-offs, and industry/location contingencies. Regarding this European textile/apparel context, several interrelated considerations create challenges with respect to balancing configuration, capabilities and location; in particular related to multiple priorities such as flexibility/delivery, quality, innovation/sustainability, and the level of product variety/customization. Several relational characteristics are also crucial, including focus on trust and information sharing, although, with a few significant exceptions, limited supplier integration levels are found. These findings indicate the need to build upon existing relationships to develop end-to-end digital connections. The thesis approaches issues at the intersection of theory and practice, regarding configuring supply networks for small series production in high-cost contexts. Practically, it develops an approach to evaluate and model decision aspects, demonstrating how this can be used with a variety of textile/apparel companies. Several extensions are required to support current and future state mapping, including developments related to the method and the addition of performance considerations. The thesis contributes to theory by broadening the focus on high-cost locations to include small series production and the SNC perspective. Thus, the research confirms multiple priorities including innovation and sustainability; additionally finding several challenges associated with small series textile/apparel production in high-cost contexts. Further research should extend the focus to understand (re)configuration processes, and implications on priorities like sustainable innovation.
10

Projeto de rede de suprimentos: um modelo colaborativo para estruturação da rede de navipeças na Indústria de Construção Naval do Brasil. / Supply network project: a collaborative framework for the structuring of the ship components network of the brazilian shipbuilding industry.

Queiroz, Adriane Angélica Farias Santos Lopes de 10 February 2009 (has links)
O objetivo deste estudo foi propor uma arquitetura de fornecimento de suprimentos capaz de garantir uma ICN Indústria de Construção Naval eficaz como um todo e eficiente no Brasil. O estudo parte da identificação e exame dos fatores condicionantes para a estruturação de uma rede de suprimentos, considerando que os recursos disponíveis na indústria podem favorecer a competitividade do todo e a natureza dessa indústria: em fase de reorganização de suas atividades e mobilizada pela entrega de projetos sob encomenda as embarcações. A proposição do framework teórico-conceitual para a estruturação da rede de suprimentos na ICN, com base em princípios colaborativos, parte de um diagnóstico geral da ICN no Brasil, caracterizando a rede de navipeças, realizado por meio de uma pesquisa do tipo survey. Com o resultado das análises, formam-se estratégias para a implantação deste modelo na rede analisada. Para tanto, consideram-se os fatores limitantes e incentivadores do seu processo de estruturação, gerando parâmetros de referência, que podem servir de base à consolidação de uma teoria sucinta sobre a gestão de relacionamentos na cadeia de suprimentos da ICN, ou até sobre o conceito de Supply Chain Management aplicado a indústrias dessa natureza. Espera-se, também, que se proporcione opção de estratégia para as empresas deste setor. / The objective of this study was the consideration of a supply network capable of guaranteeing efficiency within the Brazilian Shipbuilding Industry (ICN Indústria de Construção Naval). The study was conducted under the identification and examination of the conditional factors of the structuring of a supply network, constantly considering that the available resources of the industry can promote the competitiveness of the whole, and the nature of this industry: in phases of reorganizing its activities and mobilized by (the) its made-to-order nature. The proposal of the theoretical-conceptual framework of the supply network structure of the Shipbuilding Industry was conceived on the basis of collaborative principles, initially beginning with a general diagnosis of the industry in Brazil, and then moving into the characterization of the component suppliers by methods of conducted surveys. The analyses pointed to the formulation of strategies for the implementation of this model within the analyzed network. Finally, the strengths and weaknesses of its structuring process were pointed in order to generate references for the consolidation of a plain theory for the relationship management among a network in the Shipbuilding Industry or on the concept of applied Supply Chain Management to this nature of industries, serving as strategical options for the companies of this sector.

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