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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.
31

Optimalizace informačního systému po organizační změně / Optimalization of Information system after organizational change

Rak, Matyáš January 2010 (has links)
The thesis deals with the analysis of the company after the recent major change and its need to optimize its information system. It designs alternative solutions and selecting the optimal variant. The aim of the work is creating recommendation of the optimal design solution to streamline business processes and increase support managerial decision making. The thesis focuses in the introductory part of the theoretical bases on grip of the problem: information theory, information system and change as the key aspect in the life of the organization, with emphasis on avoiding mistakes. It also assesses the benefits of information systems measurement as the input factor for the optimization evaluation. In the practical part, the situation and process analysis is used to describe a company in which optimization is being recommended. Subsequently, the variants of optimization are introduced and decision-making model for selecting the optimal selection is designed The conclusion summarizes aspects of the evaluation of optimization of information systems.
32

A Methodology to Link Cost and Reliability for Launch Vehicle Design

Krevor, Zachary Clemetson 28 June 2007 (has links)
This dissertation is focused on the quantitative metrics of performance, cost, and reliability for future launch vehicles. Methods are developed that hold performance constant for a required mission and payload so that cost and reliability can be traded. Reliability strategies such as reducing the number of engines, increasing the thrust-to-weight ratio, and adding redundant subsystems all increase launch vehicle reliability. However, there are few references that illustrate the cost of increasing launch vehicle reliability in a disciplined, integrated approach. For launch vehicle design, integrated performance, cost, and reliability disciplines are required to show the sensitivity of cost to different reliability strategies. A methodology is presented that demonstrates how to create the necessary launch vehicle reliability models and integrate them with the performance and cost disciplines. An integrated environment is developed for conceptual design that can rapidly assess thousands of launch vehicle configurations. The design process begins with a feasible launch vehicle configuration and its mission objectives. The performance disciplines, such as trajectory analysis, propulsion, and mass estimation are modeled to include the effects of using different reliability strategies. Reliability models are created based upon the launch vehicle configuration. Engine reliability receives additional attention because engines are historically one of the leading causes of launch vehicle failure. Additionally, the reliability of the propulsion subsystem changes dynamically when a launch vehicle design includes engine out capability. Cost estimating techniques which use parametric models are employed to capture the dependencies on system cost of increasing launch vehicle reliability. Uncertainty analysis is included within the cost and reliability disciplines because of the limited historical database for launch vehicles. Optimization is applied within the integrated design environment to find the best launch vehicle configuration based upon a particular weighting of cost and reliability. The results show that both the Saturn V and future launch vehicles could be optimized to be significantly cheaper, be more reliable, or have a compromise solution by illustrating how cost and reliability are coupled with vehicle configuration changes.
33

Improving the efficiency of turkey breeding programs through selection index design, technological advancements, and management optimization

Case, Lindsay Anne 20 September 2011 (has links)
Breeding objectives in the turkey industry are heavily weighted towards improving growth traits. This thesis focused on methods to efficiently select for other important production traits such as reproduction, feed efficiency, and meat yield. Based on bivariate and random regression modeling it was determined that egg production, fertility, and hatchability were influenced by genotype by environment interactions and, as a result, the regulation of reproductive traits is by some unique genes in the summer and winter. This may be due to changes in day length and temperature. Feed efficiency is another important consideration in a breeding objective and feed conversion ratio and residual feed intake were both moderately heritable. Residual feed intake was also more independent of production traits than feed conversion. Feed intake, body weight, and weight gain were moderately heritable and progress can be made in feed efficiency by appropriately weighting these traits in an index. Infrared measures of surface temperature were then investigated to determine if they can be used to select for feed efficiency. Temperatures of the distal metatarsus, eye, neck, and head did not show a strong relationship to feed efficiency and therefore offer limited advantages to a breeding program. Selection for breast meat yield (BMY) is important and it was determined that breast muscle depth, measured with ultrasound technology, is heritable and highly correlated to the carcass trait. As a result, ultrasound traits can compliment conformation scoring and sibling testing in a breeding program to increase the accuracy of selection for BMY and increase response to selection. A deterministic model was also developed and could be used to determine optimum slaughter weight. This would optimise profits in an integrated system, enabling the industry to account for and capitalize on genetic gains. Overall, the population parameters and selection criteria identified for reproduction, efficiency, and meat yield traits identified in the present thesis could be used to increase selection efficiency in turkey breeding programs. Further, the developed production model can be used by the industry to slaughter turkeys at a time that maximizes profits, based on performance levels.
34

A method for the genetically encoded incorporation of FRET pairs into proteins

Lammers, Christoph 15 July 2014 (has links)
No description available.
35

Beneficiation of wastewater streams from gold mine process water systems with recovery of value-adding liquid waste products

Bester, Lelanie 27 November 2012 (has links)
A strategy for beneficiation of wastewater streams from fissure and process water developed for a gold mine operation in the west of Johannesburg was tested for viability in a pilot study. The investigation was aimed at evaluating the compliance of the finally discharged effluent streams with the current Water Use Licence (WUL). The core of the water recovery process consisted of softening to remove divalent cationic species, followed by ion exchange processes employing Strong Acid Cationic (SAC) resins and Weak Acid Cationic (WAC) resins. An operational design limitation was that the crystalactor used in the softening stage had a minimum capacity of 20 000 L/h, whereas the rest of the system could be operated at flow rates of as low as 2 000 L/h. For this reason, the softening step was done in semi-batch mode. Calcium hardness was decreased from 70 mg/L to values lower than 40 mg/L (as Ca2+). During the ion exchange (water recovery) process, columns using SAC resin produced better quality water than the WAC resins. The SAC columns produced water compatible with South African Water Quality Standards. Additionally, the use of SAC proved to be a more financially favourable option, since the regenerant stream contained high concentrations of calcium nitrate, magnesium nitrate and sodium nitrate fertilizer. The latter could be sold as a liquid fertilizer to farmers. In addition to the above findings, the pilot system reduced the concentration of toxic and radiotoxic metals such as uranium. The final concentration of the uranium in the effluent (0.01 mg/L) was below the regulation limit 0.07 mg/L. The selective removal of uranium is crucial in order to produce high-quality fertilizer from the ion exchange regeneration streams. Copyright / Dissertation (MEng)--University of Pretoria, 2013. / Chemical Engineering / unrestricted
36

Derivation and Analysis of Behavioral Models to Predict Power System Dynamics

Chengyi Xu (9161333) 28 July 2020 (has links)
In this research, a focus is on the development of simplified models to represent the behavior of electric machinery within the time-domain models of power systems. Toward this goal, a generator model is considered in which the states include the machine’s active and reactive power. In the case of the induction machine, rotor slip is utilized as a state and the steady-state equivalent circuit of the machine is used to calculate active and reactive power. The power network model is then configured to accept the generator and induction machine active and reactive power as inputs and provide machine terminal voltage amplitude and angle as outputs. The potential offered by these models is that the number of dynamic states is greatly reduced compared to traditional machine models. This can lead to increased simulation speed, which has potential benefits in model-based control. A potential disadvantage is that the relationship between the reactive power and terminal voltage requires the solution of nonlinear equations, which can lead to challenges when attempting to predict system dynamics in real-time optimal control. In addition, the accuracy of the generator model is greatly reduced with variations in rotor speed. Evaluation of the models is performed by comparing their predictions to those of traditional machine models in which stator dynamics are included and neglected.
37

Posouzení informačního systému firmy a návrh změn / Information System Assessment and Proposal for ICT Modification

Šejna, Tomáš January 2016 (has links)
Diploma thesis is focused on information system assessment and subsequent proposal for its modification. These changes are partly concerned on company requests, where system implemented is, but on the other hand also of development of processes in the time horizon. These proposals of changes and optimization will be afterwards presented and recommended for realization.
38

Chilled Water System Modeling & Optimization

Trautman, Neal L. 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The following thesis looks into modeling a chilled water system equipped with variable speed drives on different piece of equipment and optimization of system setpoints to achieve energy savings. The research was done by collecting data from a case-study and developing a system of component models that could be linked to simulate the overall system operation.
39

Optimization of Energy Systems for a Sustainable District in Stockholm Using Genetic Algorithms : The case of Albano

Magny, Alessandro Antoine Andrea January 2014 (has links)
Multi-objective optimization tools using genetic algorithms (GAs) are being increasingly used for improving building performances and sustainability. However, few research studies focus on district-scale solutions. In the present project, a multi-objective optimization method using genetic algorithms was applied in order to help decision makers find the optimal energy mix of a district energy system in the preliminary design phase.   A case study consisting of the new campus Albano in Stockholm (comprising lecture buildings and student residences) was used for the analysis. A wide range of energy systems was included as a design variable: wind turbines, solar thermal collectors and photovoltaic cells, ground-source heat pumps, biomass boilers, combined cooling, heating and power, district heating and district cooling. The energy provided by the chosen technologies and the district energy balances are simulated on an annual basis using a steady-state method with an hourly resolution.   Three objectives functions were to be minimized: (1) the life-cycle costs; (2) the greenhouse gas emissions; and (3) the annual non-renewable primary energy consumption of the district. The optimization process was implemented on MOBO, a multi-objective optimization tool based on genetic algorithms.   The findings include understanding the trade-offs among the three objectives and a selection of alternatives of energy supply systems to be further investigated in the detailed design phase.
40

Simulation and Analysis of Queueing System

Zhang, Yucong January 2019 (has links)
This thesis provides a discrete-event simulation framework that can be used to analyze  and  dimension  computing  systems.  The  simulation  framework  can define  and  parametrize  the  flexible  queueing  system.  We  use  the  simulation framework to explore the data collected from the real-world system. We analyze the metrics, including waiting time and server utilization of single-server and multi-server  queueing  systems.  In  particular,  we  study  the  impact  of  the number of servers on waiting time and server utilization. The experiments show it  is  possible  to  increase  server  utilization  and  decrease  the  server  number without  significantly  increasing  waiting  time,  and  flexible  architectures  canlead to significant gains. / Detta  examensarbete  tillhandahåller  ett  ramverk  som  kan  användas  för  att analysera och dimensionera dator-system. Simuleringsramverket kan definera och parameterisera ett flexibelt kösystem baserat på data från ett system i drift. Vi använder simuleringsramverket för att undersöka datat insamlat från skarpa system.  Vi  analyserar  prestandatal,  såsom  väntetid  och  utnyttjandegrad  för system  med  en  och  flera  betjänare.  Framför  allt  undersöker  vi  hur  antalet betjänare  påverkar  väntetid  och  utnyttjandegrad.   Försöken  visar  att  det  är möjligt  att  öka  uttnyttjandegraden  och  minska  antalet  betjänare  utan  att märkbart öka väntetiden, och att en flexibel arkitektur kan leda till märkbaraförbättringar. / <p>Industrial Advisors: Olga Grinchtein and Johan Karlsson </p>

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