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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.
11

An investigation of forecasting methods for a purchasing decision support system. A real-world case study of modelling, forecasting and decision support for purchasing decisions in the rental industry.

Yang, Ruohui January 2012 (has links)
This research designs a purchasing decision support system (PDSS) to assist real-world decision makings on whether to purchase or to sub-hire for equipment shortfalls problem, and to avoid shortage loss for rental business. Research methodology includes an extensive literature review on decision support systems, rental industry, and forecasting methods. A case study was conducted in a rental company to learn the real world problem and to develop the research topics. A data converter is developed to recover the missing data and transform data sets to the accumulative usage data for the forecasting model. Simulations on a number of forecasting methods was carried out to select the best method for the research data based on the lowest forecasting errors. A hybrid forecasting approach is proposed by adding company revenue data as a parameter, in addition to the selected regression model to further reduce the forecasting error. Using the forecasted equipment usage, a two stage PDSS model was constructed and integrated to the forecasting model and data converter. This research fills the gap between decision support system and rental industry. The PDSS now assists the rental company on equipments buy or hire decisions. A hybrid forecasting method has been introduced to improve the forecasting accuracy significantly. A dada converter is designed to efficiently resolve data missing and data format problems, which is very common in real world.
12

A Spatial Decision Support System for Economic Analysis of Sediment Control on Rangeland Watersheds

Duan, Yanxin January 2005 (has links)
Spatial decision support systems (SDSS) integrate the state of the art technology, such as GIS, database and distributed models into decision support systems to support geospatial analysis that is particularly useful for watershed management, such as TMDL development on watersheds required by the Clean Water Act. This dissertation focuses on the development of a SDSS to assess the economic and environmental impacts from various best management practices (BMPs) in reducing sediment yield on rangeland watersheds.The SDSS included three major parts: the models, database and web-based interfaces. The model part is the core of the SDSS that provides the functionality of watershed economic analysis. The model maximized the profit of a representative ranch assumed to cover the whole watershed with the constraints of production technology, resource, sediment control objectives and sustainable utilization. A watershed was spatially segmented into basic units, each unit with similar plant growth and forage utilization. There are two major types of models, static and dynamic. Each model type supported variations in plant growth, grazing and ranch operations. Upland erosion was estimated through RUSLE2 and the sediment yield of a watershed was estimated from upland erosion and sediment delivery ratios for each basic unit. GAMS programs were used to solve the optimization models. The SDSS provides a platform to automatically implement the models. The database was the major tool in managing spatial and non-spatial data. A series of customized web pages were developed to support users' inputs, watershed analysis and result visualization. The embedded procedures were integrated into the SDSS to support analytical functionality, including geospatial analysis, model parameterization and web page generation.The SDSS was used to assess sediment control on the Walnut Gulch Experimental Watershed. The SDSS was parameterized primarily using publicly available data and a preliminary validation was made. The SDSS functionality was illustrated through eight applications. The results showed that given recent prices, new infrastructure practices would cause a financial burden to ranches. Better grazing management may provide an economic alternative to meet the sediment control objective and cost sharing could provide ranchers the incentives to participate in conservation plans.
13

A GIS based spatial decision support system for landscape character assessment

Davey, Faye Elanor January 2012 (has links)
Landscape Character Assessment (LCA) provides a structured approach to identifying the character and distinctiveness about the landscape. It is a tool used to identify what makes a location unique, a set of techniques and procedures used to map differences between landscapes based on their physical, cultural and historical characteristics. Although the UK has committed to assessing all of its landscapes by signing the European Landscape Convention in 2006, only 60% of coverage has been achieved. The majority of LCAs are carried out by professional environment or landscape consultancies rather than ‘in-house’. Geographical Information Systems are increasingly being used to collate and analyse data and produce character maps. This research presents a Spatial Decision Support System (LCA-SDSS) based in ArcGIS 9.3 that can be used to support decision makers in conducting a LCA. The LCA-SDSS provides a method for storing data, a model base for the assessment of Landform, Ground Type, Land Cover & Cultural attributes and a method for the user to interact with the resulting maps. Using the Tamar Valley Area of Outstanding Natural Beauty (AONB) as a study area the SDSS was developed and tested, resulting in character maps for each stage of the modelling and a final characterisation map. These maps were compared to a LCA conducted by a professional environmental consultant and were found to have produced a good quality assessment as verified by the end user at the Tamar Valley AONB Partnership.
14

On Descriptive and Predictive Models for Serial Crime Analysis

Borg, Anton January 2014 (has links)
Law enforcement agencies regularly collect crime scene information. There exists, however, no detailed, systematic procedure for this. The data collected is affected by the experience or current condition of law enforcement officers. Consequently, the data collected might differ vastly between crime scenes. This is especially problematic when investigating volume crimes. Law enforcement officers regularly do manual comparison on crimes based on the collected data. This is a time-consuming process; especially as the collected crime scene information might not always be comparable. The structuring of data and introduction of automatic comparison systems could benefit the investigation process. This thesis investigates descriptive and predictive models for automatic comparison of crime scene data with the purpose of aiding law enforcement investigations. The thesis first investigates predictive and descriptive methods, with a focus on data structuring, comparison, and evaluation of methods. The knowledge is then applied to the domain of crime scene analysis, with a focus on detecting serial residential burglaries. This thesis introduces a procedure for systematic collection of crime scene information. The thesis also investigates impact and relationship between crime scene characteristics and how to evaluate the descriptive model results. The results suggest that the use of descriptive and predictive models can provide feedback for crime scene analysis that allows a more effective use of law enforcement resources. Using descriptive models based on crime characteristics, including Modus Operandi, allows law enforcement agents to filter cases intelligently. Further, by estimating the link probability between cases, law enforcement agents can focus on cases with higher link likelihood. This would allow a more effective use of law enforcement resources, potentially allowing an increase in clear-up rates.
15

A systems approach to model the conceptual design process of vertical take-off unmanned aerial vehicle.

Rathore, Ankush, ankushrathore@yahoo.com January 2006 (has links)
The development and induction in-service of Unmanned Air Vehicles (UAV) systems in a variety of civil, paramilitary and military roles have proven valuable on high-risk missions. These UAVs based on fixed wing configuration concept have demonstrated their operational effectiveness in recent operations. New UAVs based on rotary wing configuration concept have received major attention worldwide, with major resources committed for its research and development. In this thesis, the design process of a rotary-wing aircraft was re-visualised from an unmanned perspective to address the requirements of rotary-wing UAVs - Vertical Take-off UAVs (VTUAV). It investigates the conventional helicopter design methodology for application in UAV design. It further develops a modified design process for VTUAV addressing the requirements of unmanned missions by providing remote command-and-control capabilities. The modified design methodology is automated to address the complex design evaluations and optimisation process. An illustration of the automated design process developed for VTUAVs is provided through a series of inputs of the requirements and specifications, resulting in an output of a proposed VTUAV design configuration for
16

Ledningsdatabas för beslutsstöd : en studie på Electrolux i Mariestad

Eriksson, Mats, Sahlin, Stefan January 2003 (has links)
No description available.
17

ADAPTATION STRATEGIES TO IMPACTS OF CLIMATE CHANGE AND VARIABILITY ON TEHRAN WATER SUPPLY IN 2021 : AN APPLICATION OF A DECISION SUPPORT SYSTEM (DSS) TO COMPARE ADAPTATION STRATEGIES

Saemian, Sina January 2013 (has links)
In this thesis, the decision analysis process of investigating the best optimal strategy for Tehran water management in 2021 is described. Such process is normally divided into four steps including: structuring the problem; identifying feasible strategies, their impact and uncertainty; quantifying preferences; and evaluation of countermeasures and sensitivity analysis. Here, in order to structure the problem, the characteristics of Tehran with respect to water issues and its history of water management are reviewed. The state of surface waters and ground waters and a description of Tehran plan for waste water treatment are given, the most significant constraints of Tehran water sector are classified and the challenges of climate change and variability are explained. The feasible adaptation strategies are designed subsequently based on that classification, data extracted from a survey and a number of interviews with water officials and managers and ordinary citizens in Tehran. Each strategy contains a series of separate measures with different weights. The phase of quantifying preferences and elucidating utility functions is conducted based on the data available from previous studies and also the current survey. The measures include: installing water saving devices, awareness raising to change citizens’ water consumption pattern, adding new sources of surface water, investing on waste water utilization, migration control and repairing water distribution network.Different combinations of these measures provide different possibilities for formulating adaptation strategies. We compare two more discussed adaptation strategies of the spectrum of strategies; one is inclined toward exploiting more water resources while the other one is more focused on demand management. The former is mainly supported by water officials and the latter advocated by water experts we interviewed. The criteria of comparison are social acceptability, economic feasibility, time-efficiency and environmental tenability. By considering the uncertainty attributed to the criteria weights, the WEB-HIPRE DSS analysis shows that the demand-oriented strategy is the optimal one in most cases, however, if time-efficiency and/or economic feasibility gain very high significance, the strategy of water officials wins over that of experts.
18

Ledningsdatabas för beslutsstöd : en studie på Electrolux i Mariestad

Eriksson, Mats, Sahlin, Stefan January 2003 (has links)
No description available.
19

A Decision Support System for Planning and Scheduling in the cell phone LCD Panel Industry

Wu, Chen-Chieh 20 January 2005 (has links)
none
20

Window Based Digital Mapping And Feeder Management Decision Support System

Chen, Sheng-Wuen 06 June 2001 (has links)
With the performance enhancement of personal computers and the popularity of Microsoft Windowing Geographic Information System (GIS), it is becoming more viable in performing the distribution automated mapping and facility management (AM/FM). In this thesis, the relative structure of the graphic and attribute data of the distribution system with four feeders (LB33, LB34, LB35 and LB38) of the Taiwan Power Company (TPC) were built according to the true geography, referring to the street background. The related applications of the GIS included Distribution Information System (DIS) and Feeder Management Decision Support (FMDS) system by using MS Visual Basic object oriented programming. The proposed DIS links graphic objects and facility attribute data through the DDE connect and WinGIS Software, and provides a user-friendly Man-Machine Interface to manage the distribution database. As for FMDS, it is complicated to operate with colossal system information of the distribution systems. To enhance the operational efficiency and reduce cost, a fast and effective Feeder Management Decision Support is critical. With a user-friendly graphical user interface provided by mapping, effective database interface and related distribution system management algorithms, it is capable of providing the decision support, so a good decision can be made both normal and emergency conditions: 1. Decision support under the normal operation The decision system can reduce the line loss and maintain bus voltages with load transferal through feeder reconfiguration strategy. 2. Decision support under the emergency operation With fuzzy reasoning algorithm, security analysis will examine network security and an optimal switching strategy can solve the load recovery problem fast and effectively.

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