É consensual que questões políticas acarretam impactos econômicos significativos, entretanto, saber a direção e magnitude destes não é trivial. A contribuição desta dissertação ao assunto se divide em duas frentes: verificação da existência de ciclo político-orçamentário na execução de investimentos públicos; e estimação de relações macroeconômicas ao longo do ciclo político. Para o primeiro ponto, utilizou-se um modelo estrutural para a série mensal de investimento das Administrações Públicas (níveis federal, estadual e municipal), encontrando ciclos de curto e médio prazo, com duração de, aproximadamente, 2 e 4 anos, respectivamente. Ademais, os ciclos coincidem com o calendário eleitoral, sendo que suas fases de expansão se encontram no período pré-eleitoral e as de contração, sempre em anos ímpares. Para o segundo ponto, um VAR linear e outro com mudança de regime foram estimados, incorporando neste as informações obtidas pelo Modelo Estrutural. Os resultados do modelo linear indicam que investimento público causa crowding-out sobre investimento privado e que tanto investimento público quanto privado exercem efeito positivo sobre o PIB, a magnitude do segundo, entretanto, é consideravelmente superior à do primeiro. O modelo não-linear evidencia que os multiplicadores fiscais são distintos para os períodos pré e pós-eleitoral, salientando que o ajuste fiscal não implica redução da atividade econômica, e sim o contrário. O impacto dos investimentos privados sobre o crescimento, por sua vez, é sempre alto, positivo e independente de ciclo político. / There is consensus that political issues carry significant economic impact, however, it\'s not trivial to determine the direction and magnitude of these ones. The contribution of this thesis to the subject is divided into two fronts: the determination of political budget cycle in the execution of public investments; and estimation of macroeconomic relationships over the political cycle. For the first point, we used a structural model for the general government (federal, state and municipal levels) monthly series of investment, finding short and medium term cycles, with duration of, approximately, 2 and 4 years, respectively. Furthermore, the cycles coincide with the electoral calendar, since phases of expansion are in the pre-election period and the contraction ones, always in odd years. For the second point, a linear and a regime switching VAR were estimated, incorporating in the latter information obtained by the Structural Model. The results of the linear model indicate that public investment causes crowding-out in private investment and that public and private investment has a positive effect on the GDP, the magnitude of the second, however, is considerably higher than the first. The nonlinear model shows that fiscal multipliers are distinct for the pre and post-election period, stressing that the fiscal adjustment does not imply reduction of the economic activity, but otherwise. On the other hand, the impact of private investment on economic growth is always high, positive and independent of the political cycle.

Rhythmic motion is ubiquitous in nature and technology. Various motions of organisms like the heart beating and walking require stable periodic execution. The stability of the rhythmic execution of human movement can be altered by neurological or orthopedic impairment. In robotics, successful development of legged robots heavily depends on the stability of the controlled limit-cycle. An accurate measure of the stability of rhythmic execution is critical to the diagnosis of several performed tasks like walking in human locomotion. Floquet multipliers have been widely used to assess the stability of a periodic motion. The conventional approach to extract the Floquet multipliers from actual data depends on the least squares method. We devise a new way to measure the Floquet multipliers with reduced bias and estimate orbital stability more accurately. We show that the conventional measure of the orbital stability has bias in the presence of noise, which is inevitable in every experiment and observation. Compared with previous method, the new method substantially reduces the bias, providing acceptable estimate of the orbital stability with fewer cycles even with different noise distributions or higher or lower noise levels. The new method can provide an unbiased estimate of orbital stability within a reasonably small number of cycles. This is important for experiments with human subjects or clinical evaluation of patients that require effective assessment of locomotor stability in planning rehabilitation programs. / Graduate / 2018-11-22

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第22862号 / 情博第741号 / 新制||情||127(附属図書館) / 京都大学大学院情報学研究科数理工学専攻 / (主査)教授 山下 信雄, 教授 太田 快人, 教授 鹿島 久嗣 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

Due to the increase in the advances in wireless communication, there has been an increase in the use of multi-agents systems to complete any given task. In various applications, multi-agent systems are required to solve an underlying optimization problem to obtain the best possible solution within a feasible region. Solving such multi-agent optimization problems in a distributed framework preferable over centralized frameworks as the former ensures scalability, robustness, and security. Further distributed optimization problem becomes challenging when the decision variables of the individual agents are coupled. In this thesis, a distributed optimization problem with coupled constraints is considered, where a network of agents aims to cooperatively minimize the sum of their local objective functions, subject to individual constraints. This problem setup is relevant to many practical applications like formation flying, sensor fusion, smart grids, etc. For practical scenarios, where agents can solve their local optimal solution efficiently and require fewer assumptions on objective functions, the Alternating Direction Method of Multipliers(ADMM)-based approaches are preferred over gradient-based approaches. For such a constraint coupled problem, several distributed ADMM algorithms are present that guarantee convergence to optimality but they do not discuss the complete analysis for the rate of convergence. Thus, the primary goal of this work is to improve upon the convergence rate of the existing state-of-the-art Tracking-ADMM (TADMM) algorithm to solve the above-distributed optimization problem. Moreover, the current analysis in literature does not discuss the convergence in the case of a time-varying communication network. The first part of the thesis focuses on improving the convergence rate of the Tracking-ADMM algorithm to solve the above-distributed optimization problem more efficiently. To this end, an upper bound on the convergence rate of the TADMM algorithm is derived in terms of the weight matrix of the network. To achieve faster convergence, the optimal weight matrix is computed using a semi-definite programming (SDP) formulation. The improved convergence rate of this Fast-TADMM (F-TADMM) is demonstrated with a simple yet illustrative, coupled constraint optimization problem. Then, the applicability of F-TADMM is demonstrated to the problem of distributed optimal control for trajectory generation of aircraft in formation flight. In the second part of the thesis, the convergence analysis for TADMM is extended while considering a time-varying communication network. The modified algorithm is named as Time-Varying Tracking (TV-TADMM). The formal guarantees on asymptotic convergence are provided with the help of control system analysis of a dynamical system that uses Lyapunov-like theory. The convergence of this TV-TADMM is demonstrated on a simple yet illustrative, coupled constraint optimization problem with switching topology and is compared with the fixed topology setting.

Many problems faced in the engineering world are computationally intensive. Filtering using FIR (Finite Impulse Response) filters is an example to that. This thesis discusses the implementation of a fast, reconfigurable, and scalable FIR (Finite Impulse Response) digital filter. Constant coefficient multipliers and a Fast FIFO implementation are also discussed in connection with the FIR filter. This filter is used in two of its structures: the direct-form and the lattice structure. The thesis describes several configurations that can be created with the different components available and reports the testing results of these configurations. / Master of Science

<p>We are study the spaces of convolutors and multipliers in the spaces of<br />tempered ultradistributions. There given theorems which gives us the characteri-zation of all the elements which belongs to spaces of convolutors and multipliers.<br />Structural theorem for ultradistribution semigroups and exponential ultradistri-bution semigroups is given. Fourier hyperfunction semigroups and hyperfunction<br />semigroups with non-densely dened generators are analyzed and also structural<br />theorems and spectral characterizations give necessary and sucient conditions<br />for the existence of such semigroups generated by a closed not necessarily densely<br />dened operator A. The abstract Cauchy problem is considered in the Banach<br />valued weighted Beurling ultradistribution setting and given some applications on<br />particular equations.</p> / <p>U disertaciji se proučavaju prostor konvolutora i multiplikatora na prostorima temperiranih ultradistribucija. Dokazane su&nbsp;teoreme koji karakteri&scaron;u elemente prostora konvolutora i multiplikatora. Date su strukturne teoreme za ultradistribucione &nbsp;polugrupe&nbsp;i eksponenecijalne polugrupe. Furijeve huperfunkciske polugrupe i&nbsp;hiperfunkciske polugrupe sa generatorima koji su negusto definisani&nbsp;<br />su analizirani, takođe su date strukturne teoreme i spektralne karakterizacije kao i dovoljni uslovi za postojenje na takvih polugrupa&nbsp;za operator A koji ne mora biti gust. Apstraktni Ko&scaron;ijev problem je&nbsp;proučavan za težinske Banahove prostore kao i za odgovarujuće prostora ultradistribucija. Takođe su date i primene za određene klase<br />jednačina.</p>

Electron orbital theory was applied to the design of the geometrical structure of an electron multiplier for an image intensifier. A special structure satisfying production requirements was studied. Electron optical calculations consisted of determining the potential distribution and tracing the electron trajectories. Liebmann’s procedure was used to solve Laplace’s equation with constant potentials on the multiplier electrodes as boundary conditions. The trajectories were determined by solving the equation of motion in an electrostatic field using a Runge-Kutta procedure. The initial conditions for the trajectories were the initial energies, initial positions, and the initial directions of the secondary electrons. The plotted trajectories indicated the feasibility of an electron multiplier of the type studied.

Much research has been done to study the effects of spacing in laterally loaded pile groups and how the pile spacing affects lateral resistance of the piles. In this test a 9-pile group of steel piles was installed in a 3x3 configuration in sand. The piles were spaced from center-to-center at a distance of 5.65 pile diameters in the direction of the load. The pile group was laterally loaded and instrumented to collect deflection, load, and strain data. A separate single pile was similarly instrumented and tested for comparison to the pile group. The soil profile consisted of a top layer of sand about 2.5 meters deep underlain by alternating layers of fine grained soil and sand. Analysis was done in order to determine p-multipliers for the rows in the pile group. The pile group consistently resisted lower average loads than those of the single pile at the same peak deflection. Row 1 resisted equal loads to those resisted by the single pile but Row 2 and Row 3 resisted smaller loads successively. The maximum bending moments were greatest in Row 1 and decreased successively in Row 2 and Row 3, however they occurred at the same depth for the same peak deflection. Maximum bending moments for the single pile were similar to those for Row 1 in the pile group at each deflection. Group effects were more significant at greater loads with larger deflections. Higher deflection caused increased shear zone interaction and a decrease in lateral resistance. The test on the single pile was modeled using the computer program LPILE Plus version 4.0 (Reese et al., 2000). The soil profile was calibrated by alternating the input soil parameters until the curves matched between the measured and the calculated results. The new soil profile was then used to model the test on the pile group using GROUP version 4.0 (Reese and Wang, 1996). A match was made between the measured test results and those calculated using GROUP by defining p-multipliers for each of the rows. For Cycle 1 the p-multipliers were found to be 1.0, .55, and .5 for Row 1 through Row 3 respectively. For Cycle 10 the p-multipliers were found to be the same as those for Cycle 1.

A full scale MSE wall was constructed and piles were driven at various distances behind the wall. Lateral load testing was conducted and the performance of the pile, wall, and reinforcement were measured. The piles were 12.75 inch pipe piles, and the wall was reinforced with welded wire grid reinforcement. The objective of the testing was to characterize the relationship between the lateral pile resistance and the distance of the pile behind the back face of the MSE wall. Load-displacement curves are presented for the piles located behind the wall at 66 inches (5.3 diameters), 55 inches (4.3 diameters), 41 inches (3.2 diameters), and 24 inches (1.9 diameters). The lateral resistance of the piles decreases as the spacing behind the wall decreases. The results of the testing have been matched in LPILE using p-multipliers to reduce the lateral resistance. A curve has been developed showing the variation of p-multiplier with normalized pile spacing behind the wall, including data from previous studies. The curve suggests that a p-multiplier of 1 (no reduction in lateral resistance) can be used when the normalized distance from the back face of the wall to the center of the pile is at least 4 pile diameters. The p-multiplier decreases relatively linearly for smaller spacings.

High-amplitude freestream turbulence and surface roughness elements can excite a laminar boundary-layer flow sufficiently enough to cause streamwise-oriented vortices to develop. These vortices resemble elongated streaks having alternate spanwise variations of the streamwise velocity. Following the transient growth phase, the fully developed vortex structures downstream undergo an inviscid secondary instability mechanism and, ultimately, transition to turbulence. This mechanism becomes much more complicated in high-speed boundary layer flows due to compressibility and thermal effects, which become more significant for higher Mach numbers. In this research, we formulate and test an optimal control algorithm to suppress the growth rate of the aforementioned streamwise vortex system. The derivation of the optimal control algorithm follows two stages. In the first stage, to optimize the computational cost of the analysis, the study develops an efficient numerical algorithm based on the nonlinear boundary region equations (NBREs), a reduced form of the compressible Navier-Stokes equations in a high-Reynolds-number asymptotic framework. The NBREs algorithm results agree well with direct numerical simulation (DNS) results. The numerical simulations are substantially less computationally costly than a full DNS and have a more rigorous theoretical foundation than parabolized stability equation (PSE) based models. The substantial reduction in computational time required to predict the full development of a G\"{o}rtler vortex system in high-speed flows allows investigation into feedback control in reasonable total computational time, which is the focus of the second part of the study. In the second stage, the method of Lagrange multipliers is utilized -- via an appropriate transformation of the original constrained optimization problem into an unconstrained form -- to obtain the adjoint compressible boundary-region equations (ACBREs) and corresponding optimality conditions, which constitute the basis of the optimal control approach. Numerical solutions for high-supersonic and hypersonic flows reveal a significant decrease in the kinetic energy and wall shear stress for all configurations considered. Streamwise velocity contour plots illustrate the qualitative effect of the optimal control iterations, demonstrating a significant decrease in the amplitude of the primary vortex instabilities.