CHARLES UNIVERSITY IN PRAGUE FACULTY OF SOCIAL SCIENCES Institute of Sociological Studies Pavla Procházková How people buy on internet Abstract of the Diploma Thesis This thesis describes the basic principles of human behavior in shopping on the Internet. The aim was to tell whether shopping on the Internet is rational. The work deals with theories of rationality and bounded rationality theories from the perspective of sociological, economic and psychological approaches. All theories agree that the man is rational, selects the most efficient option of possible behavior. Whether the benefits gained are economic, social or psychological. From this broad perspective, it is clear that people in most cases their actions are rational, because even the deepest emotions have some rational basis, however, that over the centuries They lost its effectiveness. Perhaps it may be irrational today due to too rapid growth of technology, information overload (information is becoming more and more widely available, but their understanding is worse, a man must decide which of them to follow). Internet for shopping feature brings greater rationality in their instruments. It also restricts such perceptions, which reduces the rationality of choice. The conclusion is that people act rationally on the Internet, buying in order to...

Generating an adverse pressure gradient (APG), using a rotating cylinder in the proximity of a plane wall under a laminar freestream flow, is studied numerically in this work. The magnitude of the generated APG is a function of the gap, G, between the cylinder and the wall, and the rotational speed of the cylinder, Ω. The flow in such a configuration is characterized by periodic transient vortex shedding at high Reynolds number. A numerical model for the computation of the transient flow for this configuration is developed using the ANSYS CFD simulation tool. The model is validated against published experimental and numerical data for similar flow configurations and excellent agreement is observed. A parametric study is carried out for different combinations of G and Ω for two different Reynolds numbers of 200 and 1000 to examine the development of the resulting separation bubble due to the generated APG. The mechanism of the boundary layer separation over the plane wall and the corresponding wake dynamics is investigated. Results are presented in terms of the distribution of the pressure coefficient as well as skin friction coefficient along the wall and flow patterns around and downstream of the cylinder in the proximity of the wall. The results of these computations confirm that using a rotating cylinder over a plane wall in a freestream flow is an effective technique to generate a controlled range of adverse pressure gradients.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18993号 / 工博第4035号 / 新制||工||1621(附属図書館) / 31944 / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 萩原 朋道, 教授 松尾 哲司, 准教授 古谷 栄光 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

In order to control the energy consumed by vehicles for crossing signalized intersections, this project designs and tests a speed guidance energy-saving strategy for signalized intersections, taking drivers’ bounded rationality into consideration. This research achieves speed guidance by developing theoretical foundation of speed guidance, dividing scenarios for practise of speed guidance, and calculating optimal trajectories for vehicles. As for influence of bounded rationality, this research categorizes all drivers into three different types: aggressive drivers, normal drivers and conservative drivers. Numerical simulation of this research is focuses on a single intersection, with three traffic saturation level, represented by 346, 519 and 692 vehicles per hour. Considering the foreseeable popularization of electric cars (EV) in the close future, proportion of EV is also taken as a variable, and experiments are carried separately at three milestones of EV proportion: 0%, 30%, and 60%. The findings suggest that aggressive drivers benefit the most from the speed guidance in energy saving, and speed guidance does lest benefit to normal drivers. Both drivers’ bounded rationality and high traffic volume could lead to increase of energy consumption, while providing specifically modified speed guidance is able to achieve satisfying reductions to these effects. With increase of EVs’ proportion in the traffic flow and drop of overall energy consumption, effect of the guidance becomes comparatively worse than the previous non-EV performance of 7% to 11%, while remaining to be effective to cut off overall energy consumption by 5% to 8%. This research is able to improve normal speed guidance with more accurate and practicable guidance information for drivers in current traffic environment.

Stateflowmodels are used for describing logic and implementing state machines in modern safety-critical software. However, the complete Stateflowmodelling language is hard to formally define, therefore a subset relevant for industrial models has been developed in previous works. Proving that the execution of Stateflow models satisfies certain safety properties is intractable in general. However, bounded model checking (BMC) can be used to either prove that safety properties are satisfied up to a bounded execution depth, commonly referred to as the reachability diameter, or find a concrete counterexample. One particular safety property of interest is an invariant property. This thesis project contributes with the following. A bounded model checking tool based on symbolic execution has been developed and is called Stateflow Model Verification Tool (SMVT). This tool has been tested on synthetic models and industrial models. The performance of Stateflow Model Verification Tool (SMVT) has been measured, but not compared against the Simulink DesignVerifier (SLDV) due to licensing issues. The study has shown that many industrial models share a similar model structure. Furthermore, it has been shown that SMVT can perform well for several models. / Stateflow-modeller används för att beskriva logik and implementation av tillståndsmaskiner i modern säkerhetskritisk mjukvara. Det kompletta Stateflowspråket är väldigt komplext, och därför har forskare tidigare definierat en begränsad version av språket relevant för industriella modeller. Bevisning att exekvering av Stateflow-modeller måste uppfylla säkerhetsegenskaper, är svårlösligt rent generellt. Begränsad modellprovning kan användas antingen för att bevisa att säkerhetsegenskaper uppfylls till ett begränsat exekveringsdjup, eller för att hitta ett motexempel. En väldigt viktig säkerhetsegenskap kallas för invariant. Detta examensarbete bidrar med följande. En begränsad modellprövare baserad på symbolisk exekvering har utvecklats och kallas för SMVT. Detta verktyg har blivit testat på syntetiska modeller samt industriella modeller. Prestandan har blivit mätt, men på grund av Simulink Design Verifier (SLDV) licens har ingen jämförelse kunnat göras. Studien har visat att många industriella modeller delar samma modellstruktur. Vidare har det utvecklade verktyget SMVT visats prestera väl för flertalet modeller.

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Parliamentary research services provide parliamentarians with qualified and politically neutral knowledge on day-to-day basis. Because this is an understudied phenomenon, the aim of the study is to investigate how parliamentarians use research services from the perspective of evidence based policy making. The study was conducted with semi-structured interviews with Swedish parliamentarians and party employees of the Social Democrats, the Green Party, and the Swedish Democrats. An interview was also conducted with a representative from the Swedish Research Service. The results show that the Swedish Research Service, as an incremental knowledge producer, is used by parliamentarians to reduce insecurity, get cues and assessments and to appear legitimate. It has also been shown that there is a difference between the parties regarding search activities. The study contributes to the policy sciences by introducing an ideal type on how parliamentarians use parliamentary research services in the policy process.

Asynchronous iterative algorithms are parallel iterative algorithms in which communications and iterations are not synchronized among processors. Thus, as soon as a processing unit finishes its own calculations, it starts the next cycle with the latest data received during a previous cycle, without waiting for any other processing unit to complete its own calculation. These algorithms increase the number of updates in some processors (as compared to the synchronous case) but suppress most idle times. This usually results in a reduction of the (execution) time to achieve convergence. Optimized Schwarz methods (OSM) are domain decomposition methods in which the transmission conditions between subdomains contain operators of the form \linebreak $\partial/\partial \nu +\Lambda$, where $\partial/\partial \nu$ is the outward normal derivative and $\Lambda$ is an optimized local approximation of the global Steklov-Poincar\'e operator. There is more than one family of transmission conditions that can be used for a given partial differential equation (e.g., the $OO0$ and $OO2$ families), each of these families containing a particular approximation of the Steklov-Poincar\'e operator. These transmission conditions have some parameters that are tuned to obtain a fast convergence rate. Optimized Schwarz methods are fast in terms of iteration count and can be implemented asynchronously. In this thesis we analyze the convergence behavior of the synchronous and asynchronous implementation of OSM applied to solve partial differential equations with a shifted Laplacian operator in bounded rectangular domains. We analyze two cases. In the first case we have a shift that can be either positive, negative or zero, a one-way domain decomposition and transmission conditions of the $OO2$ family. In the second case we have Poisson's equation, a domain decomposition with cross-points and $OO0$ transmission conditions. In both cases we reformulate the equations defining the problem into a fixed point iteration that is suitable for our analysis, then derive convergence proofs and analyze how the convergence rate varies with the number of subdomains, the amount of overlap, and the values of the parameters introduced in the transmission conditions. Additionally, we find the optimal values of the parameters and present some numerical experiments for the second case illustrating our theoretical results. To our knowledge this is the first time that a convergence analysis of optimized Schwarz is presented for bounded subdomains with multiple subdomains and arbitrary overlap. The analysis presented in this thesis also applies to problems with more general domains which can be decomposed as a union of rectangles. / Mathematics