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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

Planning energy systems for small, rural communities (including economic, technical and thermodynamic criteria)

Pinney, Adam A. January 1987 (has links)
The work described in this thesis develops a strategy for planning domestic energy supply systems for small, rural communities. Two methods, for system optimisation are proposed: economic optimisation and thermodynamic optimisation. Both methods are applied to the small Scottish island of Eigg, as an example of a small community. It is shown that, for the range of energy equipment studied, the two methods are generally complementary. Economic theory and choice of parameters are discussed, as is the theoretical background to thermodynamic modelling. The net present value method is used to determine unit energy costs, which are used in the economic model as the parameter by which different energy sources are chosen. For thermodynamic assessment three parameters are used: exergy, second law efficiency and energy quality. Energy quality against quantity diagrams (on which areas represent exergy) are shown to be a useful way of visualising thermodynamic system performance. This work also develops methods which can be used to determine model inputs. These include: an energy census of the island of Eigg to determine the current energy system, development of a hydrological prediction model for determining hydro power potential, use of computer models to determine house space heating demands, and development of methods for predicting meteorological parameters from long term data. The application of the economic planning model to Eigg allows a much improved energy supply system for the island to be proposed. This makes energy more available, improves comfort (with regard to energy usage), and gives 30% higher energy usage for a lower unit cost than the islanders currently pay. The thermodynamic optimisation process improves the thermodynamic efficiency of the energy system on Eigg by more than 100% and shows which areas of energy technology should be investigated to harmonise economic and thermodynamic optimisation.
2

Development of a supply planning methodology in the automotive industry

Stark, Vanessa Ann 20 June 2005 (has links)
Supply Planning in the Automotive Industry is a vital ingredient for Supply Chain Integration. The role and function of a Supply Planner, although clearly defined in European developed methods, lacks the practical dimension. This paper describes such a practical approach that was developed for Supply Planning in the South African Automotive Industry. The framework highlights all the aspects – from a business and functional perspective - that need to be considered on a global and local scale. The framework describes the role and responsibilities of the Supply Planner as an active supply chain designer during the product/production development process. / Dissertation (MEng (Industrial Engineering))--University of Pretoria, 2006. / Industrial and Systems Engineering / unrestricted
3

Bridging the Distributor into a Collaborative Demand and Supply Planning Process

Eksoz, C., Onkal, Dilek 30 January 2018 (has links)
Yes / Based on their study of the food distribution supply chain, Can Eksoz and Dilek Önkal argue that the distributor has largely been overlooked in the principles we’ve created for collaborative demand and supply planning. Their article re-inserts the distributor into the supply chain and examines the challenges of collaboration from the distributor’s vantage point. This is a good lesson in how collaborative agreements must address the particular structures of the supply chain as well as the markets in which the supply-chain partners operate.
4

Investigation of the Water-Renewable Energy-Nexus in Transition Plans Towards Sustainability in Iran / イランにおける持続可能な社会に向けた移行計画のための水・再生可能エネルギーネクサスの研究

Ahmadi, Esmaeil 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第23293号 / エネ博第418号 / 新制||エネ||79(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 手塚 哲央, 准教授 MCLELLAN Benjamin, 教授 山敷 庸亮 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM
5

Water supply in hard rock coastal regions : The effect of heterogeneity and kinematic porosity

Earon, Robert January 2014 (has links)
Water resources in hard rock terrain are difficult to characterize due to heterogeneity and anisotropy in the fracture network, low porosities and limited recharge volumes available during the summer season. Three methods were developed and evaluated in order to assist in water supply planning. A groundwater resources potential index was estimated using multivariate statistics, where physical and geological variables were classified using Analysis of Variance and Fisher's Least Significant Difference tests according to their effect on hydraulic properties. Principal component analysis was used to assign weights to the different classed variables. Classes and weights were used to produce an index referred to as groundwater resources potential (GRP), which correlated significantly with well data. Nearly 80% of the wells with less than median specific capacity values also had GRP values at those locations of zero or lower. Non-stationary variance was observed in specific capacity sub-samples taken from the Geological Survey of Sweden's well archive, despite homogeneous geology and topography. Spatial statistical analyses showed that spatial correlations were weak in well archive samples, implying that regional approximations based on sparse point data are highly error prone. Kinematic porosity estimated using superficial fracture measurements correlated significantly with well archive data. However, low correlation coefficients indicated that well data is likely not a suitable method for predicting water supply characteristics. This approach is an efficient method which shows promise in preliminary estimations of groundwater storage in heterogenic terrains. A groundwater balance model which describes seasonal groundwater storage changes was created in order to better approximate the groundwater situation often found in Swedish urbanized and semi-urbanized hard rock terrains. The model was based on a water budget approach at the pixel scale, and allows for approximation of well extraction which is not uniformly distributed in space. The model showed that in specific regions groundwater extraction may lead to severe decreases in groundwater level, where these impacts may not otherwise be expected. Dry season modelling with 10% increased evapotranspiration showed that in several areas groundwater reservoir depletion may be influenced by more than 50%. / <p>QC 20140331</p>
6

Product Classification in Supply Chain

Xing, Lihong, Xu, Yaoxuan January 2010 (has links)
Oriflame is a famous international direct sale cosmetics company with complicated supply chain operation but it lacks of a product classification system. It is vital to design a product classification method in order to support Oriflame global supply planning and improve the supply chain performance. This article is aim to investigate and design the multi-criteria of product classification, propose the classification model, suggest application areas of product classification results and introduces the product classification system into Oriflame ERP system. The research scope is defined within Oriflame supply chain from the order placed to suppliers by Global Supply department to the products received in Global Hubs.Investigation approaches in this article including information collection, multi-criteria integration, and quantified analysis. In addition, sample calculation and test to stakeholder departments have been done after the proposal of product classification system.The product classification applies a cross tabulate matrix to classify products into four classes (ABCD classification), it is believed that the results keep consistent at high level with both the calculation time horizons‟ increasing and the monthly forecast report update.Hence, Product Classification System is supposed to be applied in supply planning prioritization, inventory management and workforce balancing, etc.
7

Integrated automotive manufacturing supply

Van Dyk, Petrus Jakobus Schoeman 10 June 2005 (has links)
Supply planning and traffic flow planning are major activities in the automotive manufacturing environment worldwide. Supply planning directly influences the traffic within a manufacturing plant. The impact of supply planning strategies like Just-in-Time, Just-in-Sequence and Direct Supply on plant traffic is rarely considered, as supply and traffic flow planning are traditionally seen as separate activities. BMW SA and other automotive manufacturers are facing various specific problems relating to supply and traffic flow planning. One of these problems is in selecting the best supplier transportation medium among various alternatives for the supply of each part family, taking into account the effects on plant traffic. Several variables have to be considered during this decision making process, and no concrete decision support tool exists at present to assist during this process. Another specific problem faced by automotive manufacturers today lies in accessing the impact of physical relocation decisions on plant traffic. Several proposed plant layout changes and changes to the location of supplier delivery points exist for BMW Plant 9 in Rosslyn. These proposed changes will imply large relocation expenses, and will inevitably have a major impact on the traffic flow within the plant. The respective impact of these proposed layout changes have to be investigated, analysed and compared. Tools developed during this project will assist automotive manufacturers during the supply planning phase of their logistics planning process. Even though these tools can function independently, their real value is only realised once they are used in conjunction with each other as a Decision Support System (DSS) (see chapter 6: Decision Support Systems). In essence, this DSS consists of a Supply Medium Decision Support Tool (SMDST) and a traffic flow simulation model. The effects of certain decisions considered during the supply planning process (as described inChapter 2: Problem Statement) and the impact of these decisions on plant traffic can now be systematically evaluated (see Figure A): -- Firstly: by means of the SMDST, which provides critical information about the cost implication and number of deliveries required for all possible combinations of part families and delivery vehicles used -- Secondly: the simulation model’s input data file can easily be updated in accordance to the SMDST’s information in preparation of a new simulation experiment -- Thirdly: the traffic flow simulation model can be run. The model will automatically use the updated input data file and create unique results files for the scenario currently under analysis -- Fourthly: the simulation model’s results files can be viewed and compared to those of previous scenarios (See figure A in 00front) All the user requirements as stated in the user requirements specifications (sections 8.2 and 9.2) have been met. Every component of the DSS was developed generically as far as possible, allowing the user to adapt it to other similar manufacturing plants with relative ease. By utilising this DSS, scenarios can be evaluated and compared faster, more efficiently and by means of more quantitative measures than before, considerably reducing uncertainty and risk of planning. Certainly, this system supports automotive manufacturers in their quest towards manufacturing excellence in an ever-increasing internationally competitive and complex environment. / Dissertation (MEng (Industrial Engineering))--University of Pretoria, 2004. / Industrial and Systems Engineering / unrestricted
8

Grundvattenbalans i Kustnära Områden

Hildingsson, Hugo January 2018 (has links)
Vatten är en livsviktig resurs för allt liv. I Sverige kommer hälften av allt dricksvatten från grundvatten. I kustnära områden begränsas grundvattentillgången av omgivningens lagringsförmåga och begränsad tillrinningsyta och det leder till att tillgången på vatten ett växande problem. Det är därför viktigt att förstå alla parametrar som påverkar grundvattnet, både för nutida och framtida brukare. Förändringen av grundvatten i geologiskt blandad miljö är svårt att kartlägga på grund av lagerföljder, materialens heterogenitet, låg kinematisk porositet och okunskap om strömningen mellan olika lager. Grundvattennivåerna skiftar dessutom med klimatet, både över året och över längre tid. Även människans påverkan är av stor betydelse. Rapportens syfte är att se hur dessa parametrar påverkar grundvattenytan i förhållande till varandra. För att undersöka dessa parametrar har tre olika geografiska, kustnära områden jämförts: Stor, Blidö, och Insjön, Rådmansö, i Norrtälje kommun samt Klintemåla i Oskarshamns kommun. För att sätta vattenanvändningen i ett sammanhang har uppgifterna relaterats till vattenexploateringsindexet (WEI). Uppgifter har hämtats från SGU, SMHI och Lantmäteriets arkiv. I två fall har kompletterande fältundersökningar genomförts. Informationen har bearbetats i Excel och programmet GWBal. I dessa områden råder lokal akut eller total vattenbrist under vissa sommarmånader. Förekomsten av vatten är en fråga om lokal tillgång och en generellt god situation i Sverige döljer stora regionala och lokala obalanser. Vad fritidsboende gör spelar större roll än permanentboende då det är under sommarsäsongen problemen är störst. Mindre reservoarer är känsligare när parametrar för klimat, vattenförbrukning och kemisk sammansättning förändras. De klimattendenser som nu uppvisas leder till konklusionen att grundvattentillgången i områdena under den kritiska perioden kommer att minska. / Water is a vital resource for all human life. Half of all drinking water in Sweden comes from groundwater and in some coastal areas, the access to water is a growing problem. It is therefore crucial to properly understand all parameters that affect the access to water, both for present and future users. The change in groundwater level in geologically varied environments is hard to get a complete picture of. Stratification, heterogeneity of soil and rock, low kinematic porosity and flow between the layers are partially unknown parameters and therefore highly uncertain. Groundwater levels also change with the climate, both over the year and over longer period of time. The impact of humans is of great importance. The objective is to see how these parameters effects groundwater level in relation to each other. To analyze these factors, three different geographic areas in Sweden will be compared: Stor, Blidö, and Insjön, Rådmansö, in Norrtälje kommun and Klintemåla in Oskarshamns kommun. To put the water use and potential stress in context, the results will be related to the Water Exploitation Index (WEI). Data was obtained from the archives of SGU, SMHI and Lantmäteriet. In two cases, the information was supplemented with field investigation. The information was processed in Excel and the program GWBal. Overall, the local shortage of water in these areas is urgent during some summer months. The water supply is a local resource and the generally good situation in Sweden conceals major regional and local imbalances. The part time residents have a much greater impact since the problem is at its peak during summer. Changes in the climate, withdrawal of water and chemical composition have greater impact on small reservoirs then on big ones. With today’s trend in climate, the conclusion is that the availability of groundwater in the areas will decrease.
9

Water Supply Planning for Landscape Irrigation in Virginia

Tucker, Adrienne Janel LaBranche 10 June 2009 (has links)
A water supply plan approach was used to investigate irrigation application on landscaped areas in Virginia with a focus on turfgrass. The economically-important turfgrass industry in Virginia should be proactive in conserving drinking water supplies to meet human consumption needs, especially in drought times. This thesis investigates current irrigation water supplies, water supply sustainability, and alternative water sources to meet irrigation demands and offers an insight on how potable water is unnecessarily consumed for non-potable irrigation needs. A Virginia evapotranspiration website was developed to offer a scientifically based source for efficient irrigation scheduling. The website was developed using a collaborative and user-centered design method, which included potential users in the process. The final website is hosted on the Virginia Tech website at http://www.turf.cses.vt.edu/Ervin/et_display.html and utilizes data from weather stations throughout the state. Evapotranspiration-based irrigation was tested at three case study sites in Blacksburg, Williamsburg and Norfolk, Virginia to assess potential water conservation. In Williamsburg, a 55% water savings was reported with evapotranspiration-based irrigation. In Blacksburg, slightly more water was applied on research greens irrigated based on evapotranspiration demand. Significantly less water was applied in Norfolk, compared to the evapotranspirationbased irrigated plots. The study also uncovered increased confidence to alter irrigation systems and the need to conduct irrigation audits when irrigating based on evapotranspiration. Evapotranspiration-based irrigation, reclaimed water and harvested rainwater were investigated to determine feasibility for meeting irrigation demands, while reducing potable water consumption at four case study sites in Blacksburg, Fairfax, Williamsburg and Norfolk, Virginia. Due to the limited collection potential at the Blacksburg site, reclaimed water and harvested rainwater was not feasible. However, the on-site weatherstation could offer a unique opportunity to calculate evapotranspiration. In Fairfax, all three alternative water sources could be integrated to supply enough water to irrigate a soccer field and adjacent athletic fields and save an estimated $7,000 per season in potable water costs. Harvested rainwater at the Williamsburg site could supplement the irrigation pond and reduce reliance on groundwater. In Norfolk, reclaimed water use is economically feasible, but rainwater harvesting could meet the irrigation needs, while evapotranspiration-based irrigation is too labor intensive for homeowners. / Ph. D.
10

Improving The Production Forecasts : Developing a Forecasting Model Using Exponential Smoothing

Ada Fatemeh, Rezai January 2024 (has links)
This research is motivated by identified gaps in contemporary planning practices and production processes within firms. Relying solely on experiential knowledge has proven limiting, necessitating a more systematic approach. Previous instances of data anomalies, particularly ongoing challenges in achieving satisfactory delivery reliability, have underlined the need for deeper insights into underlying patterns. The objectives of this study are: • To identify and analyze specific obstacles and challenges affecting load balance and delivery security in Borl.nge's production system. • To explore various methods or strategies aimed at enhancing the process of generating reliable capacity forecasting methods. Both primary and secondary research methods were employed. Primary methods included interviews and the development of a forecast model, while secondary studies encompassed the latest research in the field. The thesis revealed five primary factors hindering capacity attainment: 1. WIP(work in progress)/ slabs material shortages disrupt production flow and escalate costs due to the need for external sourcing of slabs. 2. Transport issues, including incorrect internal deliveries and the weather conditions, pose challenges. 3. Personnel shortages hinder the efficient utilization of production capacity. 4. Machine breakdowns result in production interruptions, leading to capacity loss and inefficiency. 5. Inventory problems, such as insufficient capacity and poor management, impede smooth production operations. Additionally, the second objective was addressed by implementing exponential smoothing for capacity planning forecasts. By updating forecasts every 13 weeks, this study improves the production forecast.

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