Mancur Olson states that individual, after reasonable evaluation, takes the action of free ride. The main factor of free ride lies in the goal of collective actions --- collective goods. And the non-excludability in collective goods enables consumers to benefit without sharing costs. Based on the framework of Olson¡¦s and Russell Hardin¡¦s theories of reaching the goal of collective actions, along with the theory of political entrepreneurs, this study surveys the collective actions of Tzu-Chi Foundation, in hope of depicting its factors and strategies for overcoming difficulties in collective actions. This study gives an analysis of Tzu-Chi Foundation in terms of collective actions, concluding that its selective incentives are Master Cheng Yen¡¦s unconditional love, cause & effect cycle and pursuit of pop culture. Successful marketing and computerized fund-raise tactics make people more willing to invest time and money in promoting Tzu-Chi Foundation. Few entrepreneurs are willing to bear the costs even without cooperation from other members, as they are satisfied with the collective goods provided by the group, just as Hardin states. Furthermore, one of the solutions to collective actions of free ride is to rely on organization operating by political entrepreneurs. Master Cheng Yen successfully plays the role of entrepreneur leader, adopting strategies like keeping equidistance from each political party, developing constant sense of mission within the organization, exercising mild leadership and management strategies, consolidating the Foundation with religious prospect, recruiting elites and making good use of talents...etc. Multiplied by her female leader impact on Taiwan, these factors combined are the key points of Tzu-Chi Foundation¡¦s success.

<p>During the last decade, power quality has been recognised asa global problem. Among different types of power qualityproblems, voltage sags have been identified to be one of themost severe problems for different process industries. The mostcommon reason to voltage sags is lightning strikes in powerlines. Protection equipment, usually located at switchyards,disconnect faulted power lines as soon as possible, which isapproximately 100 ms. Thus, the duration of voltage sags areapproximately 100 ms. The sensitivity to voltage sags ofelectrical equipment in process industries can be observed asfor instance malfunction, automatic turnoff or damages.</p><p>This thesis gives an overview of three metals processes withfocus on the sensitivity to voltage sags and interruptions. Theinherent energy in the process is used to find the sensitivity.This energy may also be used to obtain "ride-through" for theprocesses. The three metals processes are a blast furnaceprocess, a hot rolling mill process and a cold rolling millprocess. The main attention in this thesis is paid to the blastfurnace process, which is powered by a line-operatedsynchronous machine.</p><p>The thesis shows that the protection equipment forelectrical machines can be adjusted to avoid unnecessaryshutdowns. It is also explained why there are high torque andcurrents during voltage sags as well as after voltage sags. Itis shown that the first peak torque and current during thevoltage sags is almost proportional to the voltage change, thatis the voltage magnitude before the voltage sag minus thevoltage magnitude during the voltage sag. The first peak torqueand current after the voltage sag depends sinusoidal-like onthe duration of the voltage sag and almost proportional to thevoltage change during the voltage sag. There is no fluxsaturation during voltage sags, however after voltage sagssaturation is very likely to occur. The thesis explains why andalso how the flux is changed during and after voltage sags.</p><p>The duration of voltage sags is in many cases set by theprotection equipment located in switchyards. It is shown thatthe durations of voltage sags can be changed to durations thatwill cause less peak torque and current after voltage sags forline-operated AC-machines. It is also shown how this istheoretically achieved.</p><p><b>Keywords:</b>Rolling mill, Blast furnace, Power Quality,Synchronous machine, Asynchronous machine, Voltage sag, Voltageinterruption, Ride-through, Process disturbances, Simulation,Modelling</p>

Conventional vehicle suspensions consist of a spring and a damper, while mass is rarely used. A mass, if properly used, can also create a damping-like effect. However, a mass has only one terminal which makes it difficult to be incorporated into a suspension. In order to use a mass to achieve the damping-like effect, a two-terminal mass (TTM) has to be designed. However, most of the reported TTMs are of fixed moment of inertia (TTM-CMI), which limits the further improvement of the suspension performance and responsiveness to changes in environment and driving conditions. In this study, a TTM-based vibration absorber with variable moment of inertia (TTM-VMI) is proposed. The main component of the proposed TTM absorber contains a hydraulic-driven flywheel with sliders. The moment of inertia changes with the positions of the sliders in response to the driving conditions. The performance of the proposed TTM-VMI absorber has been analyzed via dynamics modeling and simulation and further examined by experiments. The analysis results indicate that the TTM-VMI absorber outperforms the TTM-CMI design in terms of body displacement; and ride comfort, tire grip and suspension deflection for zero and impulse inputs with comparable performance for sinusoidal input.

The thesis outlines a hierarchical modelling methodology for investigation in vehicle dynamics, in particular for combined ride and handling manoeuvres. The methodology involves the use of detailed multi-degrees of freedom models of vehicles with the inclusion of sources of non-linearity, using a multi-body approach, based on Lagrangian dynamics for constrained systems. It also includes the use of simpler and task-specific models, formulated in Newton-Euler approach. These simpler models with lower degrees of freedom, but with appropriate level of detail are more efficient in the study of specific, but non-trivial problems such as transient behaviour of vehicles in combined ride and handling, as encountered in many routine daily manoeuvres. The modelling methodology is supported by careful vehicle testing, both for validation of the proposed approach, and assessment of the extent of applicability of simple, intermediate and multi-degrees of freedom full-vehicle models. Certain important vehicle handling and ride characteristics in pitch plane dynamics, roll behaviour, vehicle body bounce and combination of these have been studied, as well as the effectiveness of restraining action of chassis elements, such as the semileading and trailing arms for passive control of vehicle squat and dive motions, arising from acceleration from coast to drive and deceleration/brake of vehicle from drive to coast. Combined pitch and bounce motions have been studied when negotiating speed traps such as bumps, which also combine with significant body roll when single event obstacles of this kind are introduced. The novelty of the research is in the detailed integrative numerical-experimental approach, and the development of intermediate models that adequately predict vehicle behaviour under steady and non-steady conditions for a wide range of ride and handling manoeuvres. The investigations have culminated in a significant number of findings of practical use, particularly the ineffectiveness of anti-squat and dive features when combined pitch and bounce motions limit the usefulness of these devices. On the contrary, excessive roll dynamic behaviour of the vehicle is effectively palliated by the anti-roll bar, even under complex combined pitch, roll and body bounce such as those experienced in negotiating single event speed bumps. Good agreement is found between the predictions of the intermediate model and those of the multi-body model and the actual vehicle tests, particularly for pitch and bounce dynamics.

Made available in DSpace on 2016-08-29T11:12:16Z (GMT). No. of bitstreams: 1 tese_6649_Dissertação - André Manhães.pdf: 1047859 bytes, checksum: 5602733dce0d5f103f7c07c76367c8c4 (MD5) Previous issue date: 2013-09-16 / O petróleo é a principal fonte energética do mundo contemporâneo, insumo básico de diversos setores econômicos. Com a descoberta do Pré-sal, o Brasil tem a oportunidade de tornar-se um dos maiores produtores de petróleo. Entretanto, para que isso seja alcançado, vários desafios deverão ser superados e, dentre eles, encontra-se o problema de transporte de empregados para operarem as plataformas offshore, distantes até 300km de distância da costa brasileira. Os problemas referentes ao deslocamento de empregados por meio de helicópteros são usualmente tratados como o Capacitated Helicopter Routing Problem (CHRP). Com base nas restrições de origem e de destino de cada cliente, no número de veículos e na capacidade e restrições de voo dos helicópteros, neste tipo de problema deseja-se minimizar os custos de aluguel de helicópteros mais o custo total de quilômetros voados. A presente dissertação propõe um modelo de Programação Linear Inteira Mista (PLIM) para o problema de roteirização de helicópteros com base no Dial-a-Ride Problem (DARP). Além do modelo apresentado, foram apresentados duas abordagens para a execução do modelo de forma exata: i) abordagem sem agrupamento, na qual as requisições que possuem origens iguais e destinos iguais são modeladas como requisições distintas e ii) abordagem com agrupamento, na qual requisições que possuem origens iguais e destinos iguais são aglutinados numa nova e única requisição. O modelo matemático foi executado no software CPLEX e os resultados mostraram que instâncias com até 25 requisições podem ser resolvidas pela abordagem com agrupamento / Oil is the main energy source of contemporary world; it is basic inputs of various economic sectors. With the discovery of Brazil pre-salt, there is an opportunity to become one of the largest oil producers. However, to achieve her own goals, Brazil must overcome several challenges, including the problem of transporting employees to operate offshore platforms 300km distant away from the Brazilian coast. Problems related to displacement of employees by helicopters are usually treated as Capacitated Helicopter Routing Problem (CHRP). Based on source and destination restrictions of each client, the number of vehicles, capacity and helicopter flight constraints, this type of problem proposes to minimize the cost of renting helicopters and the total cost of flown kilometers. This dissertation proposes a model of Mixed Integer Linear Programming (MILP) for the helicopters routing problem based on a Dial-a-Ride Problem (DARP). Besides the presented model, we presented two approaches to implementing the model in an exact way: i) non-clustered approach, in which requests that have the same origin and destination are equal modeled as separate requests; and ii) clustered approach, in which requests that have the same origins and destinations are clumped together in a new single request. The mathematical model was implemented in software CPLEX and results showed that instances with up to 25 requests can be resolved in the clustered approach

This master’s thesis is concerned of ride comfort. It uses MBS simulation software MSC Adams, especially its Car module. It contains simulations of ride over the road with obstacles that represent the everyday conditions in real traffic. The main area of focus is to find acceleration data that are present on the driver’s seat and co-driver’s seat in relation on specific suspension settings which affect the ride comfort.

This essay analyses how students translate theoretical warfare into practical action during a staff ride. Through case studies, at the actual location, in a real or fictitious scenario, students can apply theoretical knowledge about principles of warfare to practical situations. Discussion of the outcomes of different examples on the actual terrain allows a comparison of contemporary tactics and contemporary technology. The terrain is still there, albeit perhaps altered and, although the military geography’s character shifts, it is consistent. Therefore, one can compare the contemporary tactical and technical conditions with the practical conditions of the present, and draw conclusions that are relevant to modern tactics. Thus, one can learn from the historical context through staff rides as a teaching method. The essay is about the teaching situation and the method that students are exposed to during a staff ride, and how theories of warfare relate to and are used in the practical implementation of a staff ride.

L’objectif de cette étude est de contraindre les déformations au cours du Pléistocène d'une marge active à partir de l’analyse sismo-stratigraphique des sédiments conservés sur la plate-forme et la pente supérieure, le long de la marge centrale d’Equateur. A partir les données de sismique haute résolution et de carottage collectées pendant l'expédition Atacames (2012), plusieurs bassins ont été identifiés. La répartition latérale et de la succession des séquences T-R dans ces bassins montrent une distribution complexe des sédiments dans le temps et l'espace. Ce travail montre que, le long des marges actives, l’analyse sismo-stratigraphique de l’enregistrement des séquences liées aux cycles eustatiques du Pléistocène est un outil très puissant. A l'échelle locale, la subduction de seamounts perturbe et renforce l'effet de déformation régionale de la ride de Carnegie. / The aim of this study is to constrain recent deformation and stratigraphic evolution of an active margin, using sismo-stratigraphic analysis of Pleistocene sediment preserved on the margin shelf and upper slope along of the Central Ecuadorian margin. From the extensive geophysical and sedimentological investigations carried out during the ATACAMES expedition (2012), we are identified serveral basins in the Ecuadorian margin. A detailed analysis of the thickness, the lateral distribution and stacking patterns in these basins show a complex distribution of sediments in time and space. The seismic-sequence stratigraphy analysis related to eustatic cycles of the Pleistocene shows a regional regional unconformity at the base (1782-Ka as minimum age), which can correspond to the signature of the beginning of the Carnegie ridge collision.

Conventional vehicle suspensions consist of a spring and a damper, while mass is rarely used. A mass, if properly used, can also create a damping-like effect. However, a mass has only one terminal which makes it difficult to be incorporated into a suspension. In order to use a mass to achieve the damping-like effect, a two-terminal mass (TTM) has to be designed. However, most of the reported TTMs are of fixed moment of inertia (TTM-CMI), which limits the further improvement of the suspension performance and responsiveness to changes in environment and driving conditions. In this study, a TTM-based vibration absorber with variable moment of inertia (TTM-VMI) is proposed. The main component of the proposed TTM absorber contains a hydraulic-driven flywheel with sliders. The moment of inertia changes with the positions of the sliders in response to the driving conditions. The performance of the proposed TTM-VMI absorber has been analyzed via dynamics modeling and simulation and further examined by experiments. The analysis results indicate that the TTM-VMI absorber outperforms the TTM-CMI design in terms of body displacement; and ride comfort, tire grip and suspension deflection for zero and impulse inputs with comparable performance for sinusoidal input.

The trend of future wind farms moving further offshore requires much higher reliability for each wind turbine in order to reduce maintenance cost. The drive-train system and power electronic converter system have been identified as critical sub-assemblies that are subject to higher failure rates than the other sub-assemblies in a wind turbine. Modern condition monitoring techniques may help schedule the maintenance and reduce downtime. However, when it comes to offshore wind turbines, it is more crucial to reduce the failure rates (or reduce the stresses) for the wind turbines during operation since the harsh weather and a frequently inaccessible environment will dramatically reduce their availability once a failure happens. This research examines the mechanical, electrical and thermal stresses in the sub-assemblies of a doubly-fed induction generator (DFIG) wind turbine and how to reduce them by improved control strategies. The DFIG control system (the rotor-side and the grid-side converter control) as well as the wind turbine control system are well established. The interactions of these control systems have been investigated. This research examines several further strategies to reduce the mechanical and electrical stresses. The control system's coordination with the protection schemes (crowbar and dc-chopper) during a grid fault is presented as well. An electro-thermal model of the power converter has been developed to integrate with the DFIG wind turbine model, for the evaluation of the thermal stresses under different operating states and control schemes. The main contributions of this thesis are twofold. A first contribution is made by providing all the control loops with well-tuned controllers in a more integrated methodology. The dynamics of these controllers are determined from their mathematical models to minimize the interference between different control-loops and also to reduce the electrical transients. This thesis proposes a coordination strategy for the damping control, pitch control and crowbar protection which significantly reduces the mechanical oscillations. On the other hand, an integrated model of the wind turbine and converter electro-thermal system is established that can illustrate the performance integration with different control strategies.