There are many practical decision problems that fall into the category of network flow problems: numerous examples of applications can be found in areas such as telecommunications, logistics, distributions, engineering, computer science and so on. One of the most popular and valuable tools to solve network flow problems of a topological nature is the use of linear programming models. An important extension of these models is that of integer programming models that deal with problems where some, or all, of the variables are required to assume integer variables. A significant application in this class of problems is the knapsack problem that arises in different contexts such as loading containers in aircraft or satisfying the demand for various lengths of cloth which must be cut from fixed length bolts of fabric. In this study, the feasibility of representing a network flow model in a tree network model and subsequently solving it using a tree knapsack approach is investigated. To compare and validate the proposed technique, a specific case study was chosen from the literature that can be used as a basis for the research project. The said study was an oil pipeline design problem, addressed by Brimberg et al. (2003). This focuses on the optimal design of an oil pipeline network for the South Gabon oil field in Africa. The objective was to reduce oil transportation costs to a major port. Following an overview of different network flow and knapsack models, an overview of the said matter is presented. A description of the proposed tree knapsack approach and the application of this approach to the given problem is given. Results have indicated that it is feasible to apply a tree knapsack approach to solve network flow problems. / Thesis (M.Sc. (Computer Science))--North-West University, Potchefstroom Campus, 2011.

Many San Francisco residents who have achieved new wealth from the expansion of the technology industry are paying record high prices for homes. But the city is landlocked and has a limited housing supply. I study the impact of the technology boom on the increase of housing prices in the city and the outflow of the middle class, by analyzing housing supply and demand, regulations, neighboring towns, home ownership, and housing price potential solutions. I find that the increase in technology jobs creates an employment multiplier effect, decrease in housing supply, increased competition and all-cash offers, and income inequality. Policymakers and activist neighborhood groups need to focus on continually increasing housing supply through dense development incentives and legalizing in-law units.

Sammanfattning: Syftet med uppsatsen är att undersöka ungdomsarbetslösheten i Örebro kommun utifrån gymnasieelevernas egna åsikter och upplevelser. Min frågeställning ser alltså ut enligt nedan:Vad utmärker ungdomsarbetslösheten i Örebro kommun?                       Hur stor andel av ungdomarna är arbetslösa?                        Vilka drabbas av arbetslösheten? Hur ser gymnasieelever i Örebro kommun på sin framtid inom arbetsmarknaden? Uppsatsen bygger främst på enkäter som två gymnasieklasser svarat på och detta stärks upp av tidigare forskning som jag har ansett som användbar för att kunna svara på min frågeställning. Nedan följer resultatet av min undersökning: I Örebro kommun är det cirka 2 200 ungdomar i åldrarna 18-29 år som är arbetslösa och siffran ser ungefär likadan ut varje år. De ungdomar som drabbas är de som kommer från en familj där en eller båda föräldrarna är eller har varit arbetslösa, om en eller båda föräldrarna är från ett annat land eller om familjen någon gång fått hjälp i form av socialbidrag. Föräldrarnas egen situation spelar mycket stor roll för barnens framtid. Gymnasieeleverna i Örebro kommun ser olika på sin framtid, en stor del av dem är oroliga, dels på grund av den höga ungdomsarbetslösheten, men även för svårigheten att hitta ett jobb, svårigheten att skaffa sig erfarenheterna som krävs för att få ett jobb. Många ungdomar upplever även att gymnasieskolan inte har hjälpt till att förbereda dem inför arbetslivet.

Millions of cranes are used around the world. Because of their wide-spread use in construction industries, boom cranes are an important class of cranes whose performance should be optimized. One limitation of most boom cranes is they are usually attached to a stationary base or a mobile base that is only used for initial positioning and not during operation. This limits the workspace of the boom crane significantly. If a boom crane was attached to a mobile base that could be safely used during lifting operations, then the boom crane workspace could be extended significantly. The problem with using cranes, and in particular mobile cranes, is the large oscillations of the payload that are typically induced when moving the crane. One control strategy that has been used to control oscillation on other types of cranes is called Input Shaping, a command filtering technique that reduces motion-induced vibration in oscillatory systems. This thesis develops a dynamics model for a mobile boom crane and analyzes the difficulty of controlling payload oscillation on a boom crane. Input shaping will shown to be effective for controlling oscillation on boom cranes. A new method for operating a boom crane in Cartesian coordinates will also be shown. This thesis will also detail the design of a small-scale mobile boom crane for experimental and research purposes. A substantial part of this thesis will also focus on the development of new input-shaping methods for nonlinear drive systems commonly found on boom and other types of cranes. An example application of a control system featuring input shaping for an industrial bridge crane will also be discussed.

NY, Univ., Diss.--Ithaca, 2004. / Kopie, ersch. im Verl. UMI, Ann Arbor, Mich.

El presente trabajo desarrolla un estudio de paralelo entre tres momentos de la narrativa hispanoamericana (Pre Boom, Boom y Post Boom) mediante el análisis de técnica narrativa de tres obras pertenecientes a dichos momentos, a saber: Alienación de Julio Ramón Ribeyro, El Hablador de Mario Vargas Llosa y Un mundo para Julius de Alfredo Bryce Echenique. Estas obras, por ser de autores tan reconocidos, son representantes dignas cada una de su etapa en la narrativa hispanoamericana. Para realizar este estudio situamos en el tiempo los tres momentos de la narrativa a analizar, es decir, hemos considerado el contexto histórico y social que envolvió a cada uno de los escritores analizados y a las obras en cuestión. Además, hacemos referencia a las características de la literatura hispanoamericana y peruana del siglo XX de manera general. Resulta imprescindible, por ser motivo de esta tesis, realizar el análisis de técnica narrativa de cada una de las obras mencionadas para luego establecer el paralelo entre ellas. Cada obra es una pieza representativa de uno de los momentos y su análisis da pie a una generalización. / Tesis

Syftet med mitt arbete är att ta reda på och förklara vad fingerstyle respektive modern fingerstyle är. Jag gjorde det genom att analysera och spela utvald musik från genren modern fingerstyle. Efter analysen komponerade jag en låt med flera speltekniska komponenter som jag anser definierar genren modern fingerstyle. Jag kom under arbetes gång underfund med att fingerstyle är en gitarrteknik som beskriver ett sätt man spelar gitarr på. Modern fingerstyle beskriver en genre där speciella tekniker och ett progressivt sound har en central roll. Jag lärde mig flera moderna tekniker som var helt okända för mig innan arbetets start. Jag lärde mig också att skriva en låt på ett snabbare sätt än jag är van vid, eftersom jag redan innan komponeringsstarten bestämde vissa parametrar som skulle vara med i låten. Mitt arbete kan ge utökad information till den som vill veta vad fingerstyle och modern fingerstyle är.

Cauchy problems for elliptic partial differential equations arise in many important applications, such as, cardiography, nondestructive testing, heat transfer, sonic boom produced by a maneuvering aerofoil, etc. Elliptic Cauchy problems are typically ill-posed, i.e., there may not be a solution for some Cauchy data, and even if a solution exists uniquely, it may not depend continuously on the Cauchy data. The ill-posedness causes numerical instability and makes the classical numerical methods inappropriate to solve such problems. For Cauchy problems, the research on uniqueness, stability, and efficient numerical methods are of significant interest to mathematicians. The main focus of this thesis is to develop numerical techniques for elliptic Cauchy problems. Elliptic Cauchy problems can be approached as data completion problems, i.e., from over-specified Cauchy data on an accessible part of the boundary, one can try to recover missing data on the inaccessible part of the boundary. Then, the Cauchy problems can be solved by finding a so-lution to a well-posed boundary value problem for which the recovered data constitute a boundary condition on the inaccessible part of the boundary. In this thesis, we use natural linearization approach to transform the linear Cauchy problem into a problem of solving a linear operator equation. We consider this operator in a weaker image space H−1, which differs from the previous works where the image space of the operator is usually considered as L2 . The lower smoothness of the image space will make a problem a bit more ill-posed. But under such settings, we can prove the compactness of the considered operator. At the same time, it allows a relaxation of the assumption concerning noise. The numerical methods that can cope with these ill-posed operator equations are the so called regularization methods. One prominent example of such regularization methods is Tikhonov regularization which is frequently used in practice. Tikhonov regularization can be considered as a least-squares tracking of data with a regularization term. In this thesis we discuss a possibility to improve the reconstruction accuracy of the Tikhonov regularization method by using an iterative modification of Tikhonov regularization. With this iterated Tikhonov regularization the effect of the penalty term fades away as iterations go on. In the application of iterated Tikhonov regularization, we find that for severely ill-posed problems such as elliptic Cauchy problems, discretization has such a powerful influence on the accuracy of the regularized solution that only with some reasonable discretization level, desirable accuracy can be achieved. Thus, regularization by projection method which is commonly known as self-regularization is also considered in this thesis. With this method, the regularization is achieved only by discretization along with an appropriate choice of discretization level. For all regularization methods, the choice of an appropriate regularization parameter is a crucial issue. For this purpose, we propose the balancing principle which is a recently introduced powerful technique for the choice of the regularization parameter. While applying this principle, a balance between the components related to the convergence rate and stability in the accuracy estimates has to be made. The main advantage of the balancing principle is that it can work in an adaptive way to obtain an appropriate value of the regularization parameter, and it does not use any quantitative knowledge of convergence rate or stability. The accuracy provided by this adaptive strategy is worse only by a constant factor than one could achieve in the case of known stability and convergence rates. We apply the balancing principle in both iterated Tikhonov regularization and self-regularization methods to choose the proper regularization parameters. In the thesis, we also investigate numerical techniques based on iterative Tikhonov regular-ization for nonlinear elliptic Cauchy problems. We consider two types of problems. In the first kind, the nonlinear problem can be transformed to a linear problem while in the second kind, linearization of the nonlinear problem is not possible, and for this we propose a special iterative method which differs from methods such as Landweber iteration and Newton-type method which are usually based on the calculation of the Frech´et derivative or adjoint of the equation. Abundant examples are presented in the thesis, which illustrate the performance of the pro-posed regularization methods as well as the balancing principle. At the same time, these examples can be viewed as a support for the theoretical results achieved in this thesis. In the end of this thesis, we describe the sonic boom problem, where we first encountered the ill-posed nonlinear Cauchy problem. This is a very difficult problem and hence we took this problem to provide a motivation for the model problems. These model problems are discussed one by one in the thesis in the increasing order of difficulty, ending with the nonlinear problems in Chapter 5. The main results of the dissertation are communicated in the article [35].

Ce travail porte sur le développement de méthodes numériques innovantes pour la conception aéro-acoustique optimale de forme des configurations supersoniques. Ce manuscrit présente tout d'abord l'analyse et le développement des approches numériques pour la prévision du bang sonique . Le couplage du calcul CFD tridimensionnel en champ proche prenant en compte la décomposition multipolaire de Fourier et la propagation atmosphérique basée sur un algorithme de tracé de rayons est amélioré par l’intégration d'un processus automatique d' adaptation anisotrope de maillage. La deuxième partie de ce travail se concentre sur l’élaboration et l'application des techniques de conception pour l'optimisation d'une configuration aile-fuselage supersonique. Un module de conception inverse, AIDA , fournit à partir d'une signature acoustique cible au sol à faible bang sonique la géométrie de la configuration correspondante. Pour améliorer a la fois les performances acoustique et aérodynamique, des techniques d'optimisation directes de forme sont utilisées pour résoudre des problèmes d'optimisation mono et multi- disciplinaires et une analyse détaillée est réalisée. Des stratégies innovantes basées sur la coopération et les jeux compétitifs sont enfin appliquées au problème d'optimisation multidisciplinaire offrant une alternative aux algorithmes traditionnels MDO . L’hybridation de ces deux stratégies ouvre la voie a une nouvelle façon d'explorer le front de Pareto de manière efficace. Celle-ci est mise en application sur un cas pratique. / This work addresses the development of original numerical methods for the aero-acoustic optimal shape design of supersonic configurations. The first axis of the present research is the enhancement of numerical approaches for the prediction of sonic boom. The three dimensional CFD near-field prediction matched using a multipole decomposition approach coupled with atmospheric propagation using on a ray-tracing algorithm is improved by the integration of an automated anisotropic mesh adaptation process. The second part of this work focuses on the formulation and development of design techniques for the optimization of a supersonic wing-body configuration. An inverse design module, AIDA, is able to determine an equivalent configuration provided a target shaped signature at ground level corresponding to a low-boom profile. In order to improve both the aerodynamic and the acoustic performance, direct shape optimization techniques are used to solve single and multi-disciplinary optimization problems and a detailed analysis is carried out. At last, innovative strategies based on cooperation and competitive games are then applied to the multi-disciplinary optimization problem providing an alternative to traditional MDO algorithms. Hybridizing the two strategies opens a new efficient way to explore the Pareto front and this is shown on a practical case.

Master's s thesis determines potential influence of "shale miracle" observed in the U.S. since the first decade of new millennium on energy independence which has been one of the U.S. policy priorities since the 1970s' oil shocks. Technological development and innovations supported by the government triggered an unexpected and in its way unique boom, which significantly strengthened the U.S. economy. The thesis examines impact of oil crises on the U.S. energy policy, history of unconventional gas and oil extraction, and the federal involvement in energy R&D programs. Energy independence is analyzed in terms of three fundamental pillars (reducing the amount of imported oil, reducing the energy intensity of economy and increasing energy self-sufficiency). All of the models, schemes and calculations cover a period of 1973-2013. Two indicators -- improving self-sufficiency and decreasing energy intensity of the economy -- speak in favor of achievable energy independence. However, deficient energy balance suggests otherwise. In case the need to fill the gap between energy production and consumption by foreign oil imports (which have been at their historically highest values since the 1990s) remains, then a complete energy independence as well as security is just an illusion.