abstract: Bicycles and motorcycles offer maneuverability, energy efficiency and acceleration that four wheeled vehicles cannot offer given similar budget for. Two wheeled vehicles have drastically different dynamics from four wheeled vehicles due to their instability and gyroscopic effect from their wheels. This thesis focuses on self-stabilization of a motorcycle using an active control momentum gyroscope (CMG) and validation of this multi-degree-of-freedom system’s mathematical model. Physical platform was created to mimic the simulation as accurately as possible and all components used were justified. This process involves derivation of a 3 Degree-of-Freedom (DOF) system’s forward kinematics and its Jacobian matrix, simulation analysis of different controller algorithms, setting the system and subsystem specifications, and real system experimentation and data analysis. A Jacobian matrix was used to calculate accurately decomposed resultant angular velocities which are used to create the dynamics model of the system torque using the Euler-Lagrange method. This produces a nonlinear second order differential equation that is modeled using MATLAB/Simulink. PID, and cascaded feedback loop are tested in this Simulink model. Cascaded feedback loop shows most promises in the simulation analysis. Therefore, system specifications are calculated according to the data produced by this controller method. The model validation is executed using the Vicon motion capture system which captured the roll angle of the motorcycle. This work contributes to creating a set of procedures for creating a validated dynamic model for a CMG stabilized motorcycle which can be used to create variants of other self-stabilizing motorcycle system. / Dissertation/Thesis / Self-balancing test Trial 3 / Self-balancing test Trial 1 / Self-balancing test Trial 2 / Masters Thesis Engineering 2020

6 Abstract Title: Postural stability in subjects with anterior cruciate ligament injury. Objectives: The aim of this thesis was to find out if the postural stability is differed in subjects with anterior cruciate ligament injury and in the control group after the "4 steps - one leg stance" test had been performed. Methods: This study compared a group with anterior cruciate ligament injury and a control group on the basis of the "4 steps - one leg stance" test. Methods of comparison and analysis were used. Results: The test and all measurements revealed differences in postural stability between subjects with anterior cruciate ligament injury and the control group while they were standing both on operated and non-operated limb. There were also differences in postural stability concerning the one leg stance on the operated and the non-operated limb. Keywords: postural stability, injury, ACL, posturomed

This research investigated the chemistries and mechanisms involved in lead-cement systems through the study of a larger number of lead compounds.

This dissertation is a collection of three essays on the monetary and fiscal stabilization policies. Grounded in the framework of the New Keynesian model, they combine both theoretical modeling and quantitative analysis, taking into account the considerations from behavioral macroeconomics and global supply chains. Chapter 1 considers both short-term effects and long-run consequences of alternative monetary and fiscal policies under an assumption of bounded rationality. Most of the existing analyses of the interaction between monetary and fiscal policy in the monetary literature often turn crucially on assumptions that are made about outcomes far in the future, sometimes infinitely far. This is a problematic feature of rational-expectations analyses, given the limited basis for assumptions about the distant future. By relaxing this problematic assumption regarding long-expectation, while keeping other parts as close as possible to the standard New Keynesian model, I take the approach of finite forward planning to study the interplay of fiscal transfer policies and monetary policy. In particular, this approach assumes that explicit forward planning extends only a finite distance into the future, with anticipated situations at that horizon evaluated using a value function learned from past experience. Such an approach makes announcements of future policies relevant, but avoids the debates about equilibrium selection that plague rational-expectations analyses. The combined monetary-fiscal regimes that result in stable long-run dynamics are characterized, and the effectiveness of temporary changes in either type of policy as a source of short-run demand stimulus is analyzed. The effectiveness of a coordinated change in monetary and fiscal policy is shown to be greatest when decision makers' degree of foresight is intermediate in range (average planning horizons on the order of ten years), rather than shorter or longer. Chapter 2, co-authored with Michael Woodford, reconsiders several issues connected with stabilization policy, when the zero lower bound (ZLB) is a relevant constraint on the effectiveness of conventional monetary policy, under an assumption of bounded rationality. In particular, it assumes that decision makers only plan a finite distance into the future each time they must act, and use a value function from their past experiences to estimate a continuation value for their situation at the end of the planning horizon. Forward guidance regarding future monetary policy remains relevant, even if its predicted impact is quantitatively weaker, and in particular price-level targeting continues to have advantages over purely forward-looking inflation targeting during a ZLB scenario. Moreover, recognizing that planning horizons may be relatively short for some strengthens the case for systematic price-level targeting, as opposed to temporary price-level targeting only following a ZLB scenario. Fiscal transfers can be a powerful tool to reduce the contractionary impact of an increased financial wedge during a crisis, and even make possible complete stabilization of both aggregate output and inflation under certain circumstances, but the power of such policies depends on the degree of monetary policy accommodation. We also show that a higher level of welfare is generally possible if both monetary and fiscal authorities commit themselves to history-dependent policies in the period after the financial disturbance has dissipated. Chapter 3, co-authored with Shang-Jin Wei, studies the implications of global supply chains for the design of monetary policy, using a small-open economy New Keynesian model with multiple stages of production. Within the family of simple monetary policy rules with commitment, a rule that targets separate producer price inflation at different production stages, in addition to the output gap and real exchange rate, is found to deliver a higher welfare level than alternative policy rules. As an economy becomes more open, measured by the export share, the optimal weight on the upstream inflation rises relative to that on the final stage inflation. If we have to choose among aggregate price indicators, targeting PPI inflation yields a smaller welfare loss than targeting CPI inflation alone. As the production chain becomes longer, the optimal weight on PPI inflation in the policy rule that targets both PPI and CPI inflation will also rise. A trade cost shock such as a rise in the import tariff can alter the optimal weights on different inflation variables.

In this master thesis the gyroscopic stabilization of a two-wheeled amphibious concept vehicle is investigated. The key idea is to neutralize external torques applied on the vehicle by the counter torque produced from the two gyroscopes attached on the vehicle. Here the gyroscopes are used as actuators, not as sensors. When a torque is applied in order to rotate a gyroscope whose flywheel is spinning, then the gyroscope precesses and it generates a moment, orthogonal to both the torque and the spinning axis. This phenomenon is known as gyroscopic precession. As the vehicle leans from its upright position we expect to generate sufficient gyroscopic reaction moment to bring the vehicle back and get it stabilized.   We first derive the equations of motion based on Lagrangian mechanics. It is worth mentioning that we only consider the control dynamics of a static vehicle. This is the so called regulator problem where we try to counteract the effects of disturbances. The trajectory tracking (servo problem) and the water-travelling can be considered as an extension of the current project. We linearize the dynamics around an equilibrium and we study the stability of the linearized model. We then design an LQG controller, a Glover-McFarlane controller and a cascade PID controller. Regarding the implementation part, we only focus on the cascade PID controller. The results from both simulations and experiments with a small-scale prototype are presented and discussed. / <p>MARINTEKNIKDAGAR PÅ KTH 2015</p>

Thesis advisor: Shih-Yuan Liu / Despite extensive research in B–N-containing aromatic systems (most notably 1,2-azaborines) for their potential use in biomedicine and materials science, development of their oxygen counterparts, 1,2-oxaborines, remains underdeveloped. Presented herein is a straightforward route to access 1,2-oxaborines via a ring-closing metathesis strategy. Attempts to utilize the 1,2-oxaborine as a 1,3-diene in the Diels–Alder cycloaddition for potential application as a 4C + 1O synthon are also presented. Lastly, investigations regarding the aromaticity of the B–O heterocycles is probed using computations and isothermal reaction calorimetry. / Thesis (MS) — Boston College, 2017. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第18402号 / 情博第517号 / 新制||情||91(附属図書館) / 31260 / 京都大学大学院情報学研究科複雑系科学専攻 / (主査)教授 山本 裕, 教授 西村 直志, 教授 太田 快人 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

After a major flooding disaster, construction materials will be scarce during early recovery stages and any material of reasonable quality would be useful. Instead of importing higher quality material from sites a considerable distance away, on-site material may be useable. This thesis explores usage of specialty portland cements, and in some cases polymer fibers, as stabilization additives to fine grained soils with elevated moisture contents. The primary objective of this thesis is to develop strength, modulus, and ductility trends for a variety of soil types, cementitious materials, cementitious material contents, and moisture contents, and to use the data to compare specialty grind portland cements to commercially available portland cement from the same production facility. The secondary objective is to evaluate the effect of polymer fibers combined with portland cement for the same mixtures. Over 1300 Unconfined Compression (UC) tests were conducted to complete these two objectives.

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