This thesis is based on the theory of mathematical programming, on the fastfood diet problem in particular. The aim is to find an optimal menu with accordance to nutritional limitations for various groups of fastfood customers and with minimal overall prize. This model is applied on the group of foods and beverages offered in selected fastfood chains in the Czech Republic.

The aim of this Master's Thesis is to create an employee shift work schedule by using selected methods of operations research. The first part is theoretical and deals with the introduction into operational research, specifically in the field of mathematical programming and simulation models, including the possibility of computer processing. This first part highlights important subjects that will be used in the second part, which is practical and is solving a specific problem. Firstly, Cinema City Flora, which provided data for the analysis, is presented. Then there is a solution of the problem in the add-in Solver in MS Excel, and then in the program LINGO. After, a discrete simulation is created in the program SIMUL8. In conclusion, there is a summarization of the main findings and recommendations, comparison of selected methods and their applicability in practice and possibilities of further research.

This diploma thesis summarizes the necessary knowledge for the design of the pump station. It focuses on the choice of suitable pumps and control valves. It also provides information on mathematical optimization methods. By combining these two disciplines a program was created that selects the most suitable combination of pumps and valves for the assigned requirements. These can vary over time. The goal of optimization is to minimize initial and operating costs. The phenomena considered are: time-varying flow and head height, serial and parallel co-operation of pumps, throttling control, a change of characteristics for variable speed and temperature, suction height control, maximum motor output, loss in connection piping.

The subject of this doctoral thesis is the solution of logistics systems in the context of waste management. The work begins with an extensive research in the field of modelling various situations from the waste transportation chain. There are presented multiple types of practical tasks in the area of operation research applicable to waste management. Their possibilities of extension and modification are analysed for use by investors, technical services or waste collection service providers. An essential part of the work is the identification of critical parameters in the waste collection at the level of municipalities and micro-regions. Based on practical requirements, challenges related to the improvement of decision-making and planning systems are defined. The available techniques proved to be insufficient for practical problems. For the area of changes and designs of collection systems (design and modification of routes, choice of the vehicle fleet, collection plan, etc.) there are no procedures that would include a whole range of operating conditions and parameters. The boundary conditions of the task affecting fundamental requirements are highly variable. The thesis presents a comprehensive approach, which is divided into several phases. The preparation and analysis of input data focused mainly on the creation of transport infrastructure, allocation of waste collection containers and their pairing to the network, which also reduces the size of the task. Furthermore, a procedure for compliance with the rules of the road was designed using a penalty function, and an algorithm for defining imaginary edges was implemented, which will allow distinguishing the frequency of collection on selected network segments. To reduce the size of the task, a segment clustering algorithm was also designed, which will enable the calculation of the collection even for larger areas. Input parameters related to operating time and fullness of collection containers are elaborated in greater detail, as they most influence the results of the task. A great benefit is also the algorithm generating the initialization solution from historical routes. As part of the related publishing activities, environmental criteria were defined to evaluate global and local impacts of waste transportation and treatment. The outputs of the thesis are used primarily for the analysis of collection systems, to support the deployment of waste containers, planning collection routes, time schedules and dimensioning the size of the vehicle fleet. The proposed algorithms were tested in several case studies, which proved the broad applicability of a comprehensive tool in the field of waste logistics. Although the thesis is focused on modelling the collection of municipal waste, the usability of the implemented procedures is possible in other areas of waste management or other sectors.

Master‘s thesis deals with the theory of distributed optimization programs (next time just DOP), the suggestion and programme sample solver DOP and verification of the functionality of DOP ideas, principles and system architecture.

Current wireless networks still employ techniques originally designed for their xed wired counterparts. These techniques make assumptions (such as a xed topology, a static enviroment and non-mobile nodes) that are no longer valid in the wireless communication environment. Furthermore, the techniques and protocols used in wireless networks should take the number of users of a network into consideration, since the channel is a shared and limited resource. This study deals with nding an optimal solution to resource allocation in wireless mesh networks. These networks require a solution to fair and optimal resource allocation that is decentralised and self-con guring, as users in such networks do not submit to a central authority. The solution presented is comprised of two sections. The rst section nds the optimal rate allocation, by making use of a heuristic. The heuristic was developed by means of a non-linear mixed integer mathematical formulation. This heuristic nds a feasible rate region that conforms to the set of constraints set forth by the wireless communication channel. The second section nds a fair allocation of rates among all the users in the network. This section is based on a game theory framework, used for modelling the interaction observed between the users. The fairness model is de ned in strategic form as a repeated game with an in nite horizon. The rate adaptation heuristic and fairness model employs a novel and e ective information distribution technique. The technique makes use of the optimized link state routing protocol for information distribution, which reduces the overhead induced by utilising multi-point relays. In addition, a novel technique for enforcing cooperation between users in a network is presented. This technique is based on the Folk theorem and ensures cooperation by threat of punishment. The punishment, in turn, is executed in the form of banishment from the network. The study describes the performance of the rate adaptation heuristic and fairness model when subject to xed and randomised topologies. The xed topologies were designed to control the amount of interference that a user would experience. Although these xed topologies might not seem to re ect a real-world scenario, they provide a reasonable framework for comparison. The randomised network topology is introduced to more accurately represent a real-world scenario. Furthermore, the randomised network topologies consist of a signi cant number of users, illustrating the scalability of the solution. Both data and voice tra c have been applied to the rate adaptation heuristic and fairness model. It is shown that the heuristic e ectively reduces the packet loss ratio which drops below 5% after about 15 seconds for all xed topologies. Furthermore, it is shown that the solution is near-optimal in terms of data rate and that a fair allocation of data rates among all nodes is achieved. When considering voice tra c, an increase of 10% in terms of data rate is observed compared to data tra c. The heuristic is successfully applied to large networks, demonstrating the scalability of the implementation. / Dissertation (MEng)--University of Pretoria, 2013. / gm2014 / Electrical, Electronic and Computer Engineering / unrestricted

The content of this dissertation consists of three parts. In the first part, optimal control strategies are developed for Unified Power Flow Controller (UPFC) following the clearance of fault conditions. UPFC is one of the most versatile Flexible AC Transmission devices (FACTs) that have been implemented thus far. The optimal control scheme is composed of two parts. The first is an optimal stabilization control, which is an open-loop ‘Bang’ type of control. The second is an suboptimal damping control, which consists of segments of ‘Bang’ type control with switching functions the same as those of a corresponding approximate linear system. Simulation results show that the proposed control strategy is very effective in maintaining stability and damping out transient oscillations following the clearance of the fault. In the second part, a new power market structure is proposed. The new structure is based on a two-level optimization formulation of the market. It is shown that the proposed market structure can easily find the optimal solutions for the market while takeing factors such as demand elasticity into account. In the last part, a mathematical programming problem is formulated to obtain the maximum value of the loadibility factor, while the power system is constrained by steady-state dynamic security constraints. An iterative solution procedure is proposed for the problem, and the solution gives a slightly conservative estimate of the loadibility limit for the generation and transmission system.

Better utilization of the airport system capacities can significantly decrease delays, as well as number of cancelled flights. An efficient Air Traffic Control system equipped with advanced technology installations in the terminal area can help reduce flight delays and cancellations. The same technology could also help reduce accidents in the terminal area, thereby increasing the safety of the system. Due to the expense of fielding advanced technology in the terminal area, it is important to conduct realistic cost-benefit analysis to predict the life-cycle cost of the system. A computer simulation and optimization model to estimate the costs and benefits of fielding advanced technologies at airport terminal areas is introduced in this paper. The model developed is called the Cost-Benefit Analysis Terminal Investment Model (COTIM). This model considers costs and benefits to both service providers (Federal Aviation Administration and airport authorities) and users (Airlines). The model combines a simulation-optimization based approach to predict benefits and costs accrued in one day or throughout the life-cycle of the facility. We present an example to demonstrate the functionality of the model using Chicago O'Hare International Airport (ORD) equipped with the Integrated Terminal Weather System (ITWS). The Integrated Terminal Weather System (ITWS) is a relatively new technology that forecasts convective weather movements thus allowing Air Traffic Control (ATC) personnel to re-direct flights inside the terminal area efficiently. COTIM estimates flight delays and cancellations at an airport, when the airport is equipped with advanced technologies such as ITWS. The model performs cost-benefit analysis by comparing a baseline scenario without terminal area technologies against a scenario with technology. The difference between the two scenarios help decision makers justify whether technology investments are warranted of not. / Master of Science

Human and freshwater ecosystems are intrinsically interconnected. To better design effective policies, modeling tools and valuation methods are necessary to help understanding the complex reciprocal linkages between ecosystem processes and human actions, and coupled human and natural systems (CNHS) sets up a critical paradigm to do so. It is thus of both academic and empirical appeal to integrate reliable economic valuation methods with tools and models from multiple disciplines in order to quantify the feedbacks between human and natural systems and to inform better policy design. Using freshwater resources as an example, this dissertation contains three essays which integrate natural science and economics models to understand how changes in human behavior and societal policies lead to changes in ecosystem services, and how changes in ecosystem services, in return, affect human decisions. The first two essays focus on agricultural nonpoint source pollution problems in United States and examines the impacts of potential water polices on both water polluters and water demanders. Specifically, in the first essay, a novel coupling between an ecological model of within-lake hydrodynamics and an economic model of hedonic property prices has been developed to quantify the connections between nutrient loading, lake water quality, and economic outcomes. Linking ecological processes with human decision-making provides a basis for enhanced evidence-based decision making in the context of reducing nonpoint-source pollution. In the second essay, an economic mathematical programming model is coupled with an agro-ecosystem model to investigate the behavioral adjustments and environmental pollution outcomes of water quality policies. A complete quantification of costs from all regulating sources are necessary to help pinpoint the efficient water policy design and reflecting the connection between human decisions and ecosystem processes. The third essay focus on the water quantity problem in another developed country, Australia. A discrete choice experiment method has been explored and used to provide estimates of willingness to pay for purchasing irrigation rights to restore a Ramsar-convention wetland. Water policy scenario described in this essay could directly affect the feedback between human and ecosystem processes and serve as a baseline for future planning and policy designs. By offering both conceptual and methodological advancements, this dissertation aims to improve the understanding of coupled human and natural systems and the implementation of water policies. This dissertation also provides a framework to establish multi-disciplinary dialogues and cooperation between scientists and economists in the search of efficient water polices. / Doctor of Philosophy / Freshwater resources are one of the most important elements in our daily life. It provides important goods and services to our society, but at the same time, due to human behaviors, freshwater resources are under threat in both their quality and quantity. This dissertation contains three essays which integrate knowledge from multiple disciplines to help understand and quantify the linkages between human and freshwater resources, and provides information to come up with better water polices. In the first essay, I explore the connections between nutrient loading, lake water quality, and the economic outcomes. The essay illustrates how potential change in nutrient loadings affect lake water quality, and how that induces people’s housing purchase behavior, property sales price and local governments’ property tax revenue. In the second essay, I focus on the agricultural production problem, which is one of the largest source for water quality degradation. By exploring the impacts of water policy on farmers’ production decisions, the essay sheds light on how to better design water polices to maintain farmers’ profit while simultaneously alleviating the impact of agricultural production to water qualities. In the third essay, I utilize a survey method, choice experiments, to elicit people’s willingness to pay for wetland ecosystem health. This could better allocate water resources between agricultural production use and residential use and come up with better water quantity polices.

As one of the fastest growing regions in the world, crop production and education remain two of the most important topics for the development of sub-Saharan African (SSA) countries. This dissertation is composed of three chapters that investigate the economic returns to education (Chapter 1 and 2) and assess the policy influence on fertilizer usage (Chapter 3) in two SSA countries, Zimbabwe and Ethiopia. Chapter 1 investigates the casual impact of improved educational attainment on household well-being as reflected by consumption level in Zimbabwe. We use the age-specific exposure to the 1980 education reform as the instrument for the household head educational attainment to identify the economic returns to education. We find that an extra year of household head schooling leads to an 8% increase in per capita household consumption on average when using the multiple rounds of the Income, Consumption and Expenditure Survey (ICES). The impact of enhanced education on household consumption is larger for rural and female-headed households and we also find some evidence that head educational attainment could affect consumption patterns, where additional schooling leads to slightly lower consumption share in food and higher share in non-durable goods. Chapter 2 extends this topic by utilizing a pseudo panel data constructed with multiple waves of repeated cross-sectional data, which allows us to use fixed-effect and other panel data methods to address the problem of unobserved "ability" bias. For pseudo panel, we use age, gender and some other time-persistent criterions to define the cohorts and replace the individual observations with the intra-cohort means. Individual time-invariant factors that influencing both education and consumption are transformed into cohort time-invariant factors, within transformation on the pseudo panel would eliminate such factors leads to achieve unbiased and consistent estimates on the returns to education. We find on average there is a 14% increase in monthly household per capita consumption for each one more year of education for the household head. By further disaggregating our population, we find female-headed households exhibit a return to education of around 15.3%, much higher than its corresponding OLS/IV estimates. On the other hand, we fail to detect such large discrepancy for the male-headed households, suggesting that the overall downward bias of OLS/IV estimates mostly come from female-headed households. Facing significant higher opportunity cost, Zimbabwean females are much less likely to furthering their education when compared to males with similar unobserved ability level which can be one of the major underlying reasons. Chapter 3 investigates the potential effect of fertilizer promotion polices on crop acreage and input intensities in Ethiopia. We use a fully calibrated multi-input and -output model based on the principle of positive mathematical programming (PMP) to assess the policy impact in four major agricultural states in the country. I analyze two policies designed to promote fertilizer use, namely fertilizer import expansion and a universal subsidy program. The results from the simulation model suggest that local farmers actively respond to these promotion policies by adjusting crop acreage and investing more in fertilizer input. However, when the availability of fertilizer in one region is fixed and local farmers face a binding constraint, the behavior responses to the subsidy program alone would be limited. / Doctor of Philosophy / Education and food production are two of the most important issues when we study the development in Sub-Saharan African countries, which are among the fastest developing regions in the world. The dissertation is composed of three manuscripts, aiming to evaluate the economic returns to education and the impact of fertilizer promotion policies in two of the SSA countries, Zimbabwe and Ethiopia. Chapter 1 investigates the returns to education as reflected by household consumption and finds significant positive effect of enhanced education on household well-being. We also find such effect is larger for rural and female-headed households which shed light on the policy of more public investment targeting female and rural education in developing countries. Chapter 2 further extends this topic by combining multiple rounds of survey data and finds larger educational effects on household consumption compared to the results in Chapter 1. Female household heads, facing more barriers in attaining higher education, are an important cause of the higher estimates of returns found in this chapter. Chapter 3 investigates how potential fertilizer promotion polices would affect the regional level of choices on crop acreage and fertilizer input intensities in the major agricultural states in Ethiopia. It finds local farmers will actively adjust their land and fertilizer inputs when facing a fertilizer import expansion in combined with a universal fertilizer subsidy program.