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Thesis (M Sport Sc)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: This study investigated the optimal training load required for peak-power production in two types of exercises, namely an Olympic-type and a ballistic exercise. The hang clean and the squat jump were selected to represent these two types of exercise. It was ascertained whether a change in strength levels and training status will have an effect on the optimal loads for peak-power production of rugby players. In addition, the influence that different playing positions have on power production was also investigated. Fifty-nine under-21 male rugby players (Mean Age 19.3yrs; SD ± 0.7yr) from two rugby academies, performed a maximal-strength test in the hang clean and squat, followed by a power test in the hang clean and squat jump with loads ranging from 30 to 90% of maximal strength (1RM). Testing was conducted in the pre-season phase and repeated during the inseason phase. Peak power for the hang clean was achieved at 90% 1RM in the pre-season and at 80% 1RM during the in-season. Peak power for the squat jump was achieved at 90% 1RM in the pre-season. However, this location of the optimal loading was not significantly higher than that of the other loadings (60, 70 and 80% 1RM). During the in-season, peak power for the squat jump was reached at 90% 1RM. Here again, the optimal-loading location was not significantly higher than that of the other loadings (50, 60, 70 and 80% 1RM). It was concluded that the optimal load for power production is 90% 1RM for the hang clean and 60-90% for the squat jump. It was found that an improvement in strength levels of the subjects affected both peak-power production and the optimal load in both exercises. During the in-season peak power in the hang clean was reached at 80% 1RM, and at 50% 1RM for the squat jump. There were no significant differences in the performances of subjects from different playing positions (forwards versus backline players). In the hang clean, peak-power production seems to be reliant on increased strength and results in peak-power output at high loads. The squat jump, on the other hand, is more reliant on velocity due to its ballistic nature and is possibly better suited to developing power at lighter loadings. Because it produces peak power at a lower percentage load than the hang clean, the squat jump could be more effective in power development for players who are inexperienced in power training. Long-term exercise periodisation in power training can therefore be employed progressively from simpler exercises (e.g., squat jump) using only the legs, to more complex exercises (e.g., Olympic-lifting) that involve the whole body. This study confirmed that the specific requirements of different sport codes should be considered meticulously before selecting and prescribing exercises and loads for power-training programmes. / AFRIKAANSE OPSOMMING: Die hooffokus van hierdie studie was op die optimale oefenlading wat vereis word vir die produsering van piek-profkrag tydens die uitvoering van twee tipes oefening, naamlik ’n Olimpiese- en ’n ballistiese oefening. Die hang clean en die squat jump is geselekteer om bogenoemde twee tipes oefening te verteenwoordig. Daar is bepaal of ’n verbetering van die krag-vlakke en oefenstatus van rugbyspelers ’n invloed het op die optimale ladings vir piek-plofkrag ontwikkeling. Verder is die moontlike rol van verskillende speelposisies ondersoek. Nege-en-vyftig onder-21 mans-rugbyspelers (M-ouderdom 19.3jr; SD ± 0.7jr) vanuit twee rugbyakademies het ’n maksimale-krag toets in die hang clean en squat uitgevoer. Dit is opgevolg deur ’n plofkrag-toets in die hang clean en squat jump met ladings wat gewissel het van tussen 30 en 90% van maksimale werkverrigting (1RM). Toetsing het plaasgevind in die voor-seisoen fase en is herhaal tydens die daaropvolgende speelseisoen. Piek-plofkrag vir die hang clean is bereik tydens ’n oefenlading van 90% 1RM in die voor-seisoen en by 80% 1RM later in die speelseisoen. Piek-plofkrag vir die squat jump is behaal by 90% 1RM in die voor-seisoen fase. Hierdie optimale lading-lokasie was egter nie beduidend hoër as by die ander ladings van 60, 70 en 80% 1RM nie. Tydens die speelseisoen is piek-plofkrag bereik in die squat jump by 90% 1RM. Die optimale lading-lokasie was weereens nie beduidend hoër as by die ander ladings van 50, 60, 70 en 80% 1RM nie. Daar is tot die gevolgtrekking gekom dat die optimale oefenlading vir die ontwikkeling van piek-plofkrag vir die hang clean 90% 1RM is, en 60% vir die squat jump. Daar is ook gevind dat ’n verbetering in kragvlakke van die toetslinge, beide piek-plofkrag-produksie en die optimale oefenbelading in albei oefeninge beïnvloed. Tydens die speelseisoen is piek-plofkrag behaal in die hang clean by 80% 1RM, en by 50% 1RM in die squat jump. Geen beduidende verskille in werkverrigting is gevind tussen toetslinge uit verskillende speelposisies (voorspelers versus agterlyn-spelers) nie. Dit blyk dat in die hang clean, die produksie van plofkrag beïnvloed word deur ’n verbetering in krag en dat dit tot hoër optimale ladings vir piek-plofkrag produksie lei. Die squat jump, in teenstelling, is meer afhanklik van snelheid en is moontlik beter geskik vir die produsering van plofkrag teen ligter oefenladings. Omdat die squat jump piek-plofkrag genereer teen laer ladings as die hang clean, kan dit meer effektief wees vir spelers met gebrekkige ervaring in krag-oefening. Lang-termyn oefen-periodisering in plofkrag-oefening kan gevolglik progressief aangewend word vanaf eenvoudiger oefeninge (bv. squat jump), waar slegs die bene gebruik word, tot meer komplekse oefeninge (bv. Olimpiese-gewigoptel) waar die hele liggaam betrek word. Hierdie studie bevestig dat die spesifieke vereistes van verskillende sportkodes deeglik oorweeg moet word alvorens oefeninge en ladings geselekteer en voorgeskryf word vir plofkrag-programme.

This dissertation spans topics related to global trade, oil prices, optimum currency areas, the eurozone, monetary independence, capital controls and the international monetary policy trilemma. It consists of four chapters and three essays. Chapter one provides a brief summary of all three essays. Chapter two investigates the impact of oil prices on global trade. It is concluded that when oil prices increase, countries start trading relatively more with their neighbors. As an application this chapter provides a new estimate of the eurozone effect on trade. Chapter three continues to study the eurozone and asks whether it is an optimum currency area using the member countries’ desired monetary policies. It is concluded that Greece, Spain, and Ireland have desired policies that are the least compatible with the common euro policy and are therefore the least likely to have formed an optimum currency area with the euro. Chapter four provides a new methodology in testing the international trilemma hypothesis. It is concluded that the trilemma holds in the context of the Asian countries.

There are four chapters in my dissertation. Chapter one gives a brief introduction of the three essays. Chapter two studies the choice of exchange rate regimes in East Asia using a business-cycle approach. My results suggest that countries in East Asia are driven mainly by country-specific shocks, making more rigid exchange rate regimes less desirable. Neither a yen bloc nor a dollar bloc has been identified in East Asia. However, Japan seems more influential to countries such as Korea and Taiwan. An optimum currency area does not seem feasible for East Asia, at least in the short run. Chapter three applies the cointegration and causality analyses to the real effective exchange rates to study the degree of monetary integration in East Asia. I find that the ASEAN and the NIE countries, respectively, have achieved some degree of integration, but not East Asia as a whole. The yen is found to move closely with the NIE currencies. However, neither the yen nor the dollar imposes a dominant driving force on the East Asian currencies. My results suggest that East Asia is not an optimum currency area. Chapter four expands the traditional monetary model of exchange rate determination into a structural VAR model incorporating various capital flows and the balance of trade in addition to the macroeconomic fundamentals. The model is then applied to the Australian dollar (AUD), the Canadian dollar (CAD), and the US dollar (USD) exchange rates over 19802004. I find that capital flows, especially portfolio investments, explain a major portion of the exchange rate fluctuations in the relatively small and open economies such as Australia and Canada in the short-to-medium run. The impacts of capital flows are limited to the US dollar exchange rates. Among the macroeconomic fundamentals, the interest rate plays an important role in exchange rate determination for all three currencies. The results imply that different capital flows do influence exchange rates differently and are important determinants of exchange rates.

O problema da árvore geradora de comunicação ótima recebe um grafo com comprimentos não negativos nas arestas e um requerimento não negativo entre cada par de vértices; sendo o objetivo encontrar uma árvore geradora do grafo que minimize o custo de comunicação, que é a soma sobre cada par de vértice da distância entre eles na árvore vezes o requerimento entre eles. Este problema é NP-difícil, assim como vários casos particulares dele. Neste trabalho estudamos algumas variantes deste problema, introduzimos novos casos particulares que são também NP-difíceis e propomos esquemas de aproximação polinomial para alguns deles. / The optimum communication spanning tree problem receives a graph with non-negative lengths over the edges and non-negative requirements for each pair of nodes; being the objective to find a spanning tree of the graph that minimizes the communication cost, which is given by the sum, over each pair of nodes, of the distance, in the tree, between the nodes multiplied by the requirement between them. This problem and several of its particular cases are NP-hard. In this work we study some of the variants, also we introduce new NP-hard particular cases of the problem and propose polynomial approximation schemes for some of them.

This dissertation studies several problems centered around developing a better understanding of the energy efficiency of cooperative wireless communication systems. Cooperative communication is a technique where two or more nodes in a wireless network pool their antenna resources to form a "virtual antenna array". Over the last decade, researchers have shown that many of the benefits of real antenna arrays, e.g. spatial diversity, increased range, and/or decreased transmission energy, can be achieved by nodes using cooperative transmission. This dissertation extends the current body of knowledge by providing a comprehensive study of the energy efficiency of two-source cooperative transmission under differing assumptions about channel state knowledge, cooperative protocol, and node selfishness. The first part of this dissertation analyzes the effect of channel state information on the optimum energy allocation and energy efficiency of a simple cooperative transmission protocol called "orthogonal amplify-and-forward" (OAF). The source nodes are required to achieve a quality-of service (QoS) constraint, e.g. signal to noise ratio or outage probability, at the destination. Since a QoS constraint does not specify a unique transmit energy allocation when the nodes use OAF cooperative transmission, minimum total energy strategies are provided for both short-term and long-term QoS constraints. For independent Rayleigh fading channels, full knowledge of the channel state at both of the sources and at the destination is shown to significantly improve the energy efficiency of OAF cooperative transmission as well as direct (non-cooperative) transmission. The results also demonstrate how channel state knowledge affects the minimum total energy allocation strategy. Under identical channel state knowledge assumptions, the results demonstrate that OAF cooperative transmission tends to have better energy efficiency than direct transmission over a wide range of channel conditions. The second part of this dissertation focuses on the development of an opportunistic hybrid cooperative transmission protocol that achieves increased energy efficiency by not only optimizing the resource allocation but also by selecting the most energy efficient cooperative transmission protocol from a set of available protocols according to the current channel state. The protocols considered in the development of the hybrid cooperative transmission protocol include compress-and-forward (CF), estimate-and-forward (EF), non-orthogonal amplify-and-forward (NAF), and decode-and-forward (DF). Instantaneous capacity results are analyzed under the assumption of full channel state knowledge at both of the sources and the destination node. Numerical results are presented showing that the delay limited capacity and outage probability of the hybrid cooperative transmission protocol are superior to that of any single protocol and are also close to the cut-set bound over a wide range of channel conditions. The final part of this dissertation focuses on the issue of node selfishness in cooperative transmission. It is common to assume in networks with a central authority, e.g. military networks, that nodes will always be willing to offer help to other nodes when requested to do so. This assumption may not be valid in ad hoc networks operating without a central authority. This section of the dissertation considers the effect selfish behavior on the energy efficiency of cooperative communication systems. Using tools from non-cooperative game theory, a two-player relaying game is formulated and analyzed in non-fading and fading channel scenarios. In non-fading channels, it is shown that a cooperative equilibrium can exist between two self-interested sources given that the end of the cooperative interaction is uncertain, that the sources can achieve mutual benefit through cooperation, and that the sources are sufficiently patient in the sense that they value future payoffs. In fading channels, a cooperative conditional trigger strategy is proposed and shown to be an equilibrium of the two-player game. Sources following this strategy are shown to achieve an energy efficiency very close to that of a centrally-controlled system when they are sufficiently patient. The results in this section show that cooperation can often be established between two purely self-interested sources without the development of extrinsic incentive mechanisms like virtual currency.

Neste trabalho, buscou-se compreender a morfologia e os componentes do sinal da deglutição. Na busca desse entendimento diversas técnicas foram empregadas. No intuito de fazer marcações fidedignas em trechos específicos do sinal, o qual foi analisado simultaneamente com a imagem da videofluoroscopia da deglutição, considerado o melhor método atual na avaliação da dinâmica da deglutição. Os parâmetros numéricos utilizados para análise também foram abrangentes e com base em técnicas atuais de processamento de sinais, como emprego de transformada Wavelet. Quanto à classificação dos sinais, foram utilizados classificadores modernos como floresta de caminhos ótimos, máquinas de vetores de suporte, redes neurais artificiais e classificador Bayesiano, dando maior ênfase ao primeiro, por possuir um custo computacional bem menor quando comparado aos outros 3, e consequentemente convergindo mais rapidamente ao resultado. Foram avaliados 84 sinais, divididos em 2 grupos separados pela consistência do bolo alimentar oferecido (líquido e pastoso). Na distinção e/ou caracterização desses tipos foi definido um subconjunto com 4 variáveis que proporcionou uma boa acurácia na separação das classes representantes de cada tipo de bolo alimentar. / This work proposes to understand the morphology and the components of the swallowing signal. In pursuit of this understanding, a variety of techniques were employed. In order to make reliable markings on specific portions of the signal, the signal was examined simultaneously with videofluoroscopic swallowing, which is considered the best method in the evaluation of swallowing dynamics. The parameters used for numerical analysis were based on current signal processing techniques, such as: Wavelet transform, Optimum path forest, Support vector machines, Artificial neural networks and Bayesian classifier, emphasizing the first technique, due to a much lower computational cost when compared to the previous, and, consequently, the results converged much faster. Eighty four signals, divided into 2 groups separated by the consistency of food bolus offered (liquid and thickened), were evaluated. For distinction and/or characterization of such types, a subset with 4 variables was defined, providing a good accuracy in the separation of these classes representing each type of consistency of the food bolus.

Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Ocean Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Includes bibliographical references. / by H.T. Chen. / Ph.D.

The goal of this diploma thesis is to assess the suitability and readiness of the Slovak Republic to adopt a single European currency. In analyzing the costs and benefits relating to Slovakia?s accession to the EMU, this thesis is guided by the theory of the OCA. The thesis provides a survey of the OCA theory, attempts to measure some of the OCA indicators and calculate OCA index for Slovakia. The results suggest that Slovakia fulfils the necessary condition for joining the monetary union, i.e. it is relatively well aligned with the euro area. The diploma thesis concludes that Slovakia is relatively suitable and well-prepared to join the euro area in 2009.

Práce se zabývá ekonomickou analýzou kybernetického zločinu. Základním východiskem analýzy je model jednání racionálního kybernetického zločince rozhodujícího se o očekávaných nákladech a užitcích své činnosti vyjádřené v jednotkách peněžního ekvivalentu. Rozhodovací problém kybernetického zločince tvoří optimalizační úlohu z vzhledem k jeho nákladům. V rámci práce je odvozen rovnovážný optimální stav zločince. Další diskutovanou problematikou jsou metody boje proti kybernetickému zločinu a detailní rozbor metody zvýšené intenzity boje. Metoda zvýšené intenzity boje je založena na snižování počtu spáchaných kybernetických zločinů pomocí mechanismu zvyšujícího náklady zločincům. Mezní zločinci jsou v případě komerční varianty zločinu vytlačeni z trhu, zbývající alespoň sníží svoji produkci. Naopak pro specifickou verzi komunitní varianty zločinu tato metoda vede ke zvýšení trestné činnosti. Posledním tématem je interakce výrobců softwaru působícího síťové efekty, spotřebitelů a softwarových pirátů. Práce obsahuje model nerozvinutého a rozvinutého trhu a variantu s dokonalou cenovou diskriminací. Ukazuje se, že na rozvinutém trhu může monopolní výrobce softwaru svoji pozici vylepšit snahou o zvyšování intenzity boje se zločinem, přičemž v případě s cenovou diskriminací tento mechanismus nemá limit a teoreticky může působit až do úplného vymýcení softwarového pirátství.