Motivated by the end of Moore’s law, graphics processing units (GPUs) are replacing general-purpose processors as the main source of computational power in emerging supercomputing architectures. A challenge in systems with GPU accelerators is the cost of transferring data between the host memory and the GPU device memory. On supercomputers, the standard for communication between compute nodes is called Message Passing Interface (MPI). Recently, many MPI implementations support using GPU device memory directly as communication buffers, known as GPU-aware MPI. One of the most computationally demanding applications on supercomputers is high-fidelity simulations of turbulent fluid flow. Improved performance in high-fidelity fluid simulations can enable cases that are intractable today, such as a complete aircraft in flight. In this thesis, we compare the MPI performance with host memory and GPU device memory, and demonstrate how GPU-aware MPI can be used to accelerate high-fidelity incompressible fluid simulations in the spectral element code Neko. On a test system with NVIDIA A100 GPUs, we find that MPI performance is similar using host memory and device memory, except for intra-node messages in the range of 1-64 KB which is significantly slower using device memory, and above 1 MB which is faster using device memory. We also find that the performance of high-fidelity simulations in Neko can be improved by up to 2.59 times by using GPU-aware MPI in the gather–scatter operation, which avoids several transfers between host and device memory. / Motiverat av slutet av Moores lag så har grafikprocessorer (GPU:er) börjat ersätta konventionella processorer som den huvudsakliga källan till beräkningingskraft i superdatorer. En utmaning i system med GPU-acceleratorer är kostnaden att överföra data mellan värdminnet och acceleratorminnet. På superdatorer är Message Passing Interface (MPI) en standard för kommunikation mellan beräkningsnoder. Nyligen stödjer många MPI-implementationer direkt användning av acceleratorminne som kommunikationsbuffertar, vilket kallas GPU-aware MPI. En av de mest beräkningsintensiva applikationerna på superdatorer är nogranna datorsimuleringar av turbulenta flöden. Förbättrad prestanda i nogranna flödesberäkningar kan möjliggöra fall som idag är omöjliga, till exempel ett helt flygplan i luften. I detta examensarbete jämför vi MPI-prestandan med värdminne och acceleratorminne, och demonstrerar hur GPU-aware MPI kan användas för att accelerera nogranna datorsimuleringar av inkompressibla flöden i spektralelementkoden Neko. På ett testsystem med NVIDIA A100 GPU:er finner vi att MPI-prestandan är liknande med värdminne och acceleratorminne. Detta gäller dock inte för meddelanden inom samma beräkningsnod i intervallet 1-64 KB vilka är betydligt långsammare med acceleratorminne, och över 1 MB vilka är betydligt snabbare med acceleratorminne. Vi finner också att prestandan av nogranna datorsimuleringar i Neko kan förbättras upp till 2,59 gånger genom användning av GPU-aware MPI i den så kallade gather– scatter-operationen, vilket undviker flera överföringar mellan värdminne och acceleratorminne.

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Author: Bc. Tomáš Zajíček Title: Analysis of game activities of goalkeeper during European Championship Under-21 2015. Objectives: The main objective is to analyse of game activities of goalkeeper on European Chapmionship Under-21 2015. Partial objectives: ranking of all matches on European Chapmionship Under-21 2015 in football, completing data, frequency of game activities, ratio of defensive and offensive game activities of goalkeeper and comparing the effect of regular and irregular performance on the goalkeeper on European Chapmionship Under-21 2015 in Czech republic. Methods: For getting information there were used indirect observation in this Bachelor thesis. The indirect observation from videorecords was time postponed. Results: The results show that in current football the goalkeeper has to be in control of the game with his foot more than ever before. A study points to the fact that the goalkeeper has to offend four times more than defend during the game. Available data show that U21 goalkeepers run less towards center balls than their older colleagues. The data also show that especially defense experience and regular utilization during the game shows. Keywords: Goalkeeper, game activities of goalkeeper, catching ball, rebound ball, running out for centered balls, taking ball, throwing...

本研究一方面剖析馬來西亞僑生來台前的教育歷程以及他們選擇來台的原因，另一方面亦深入探討馬來西亞僑生群體內部之國籍異質性對其在台生活經驗及「僑生」身分認同上的影響。本研究採用質性研究方法進行研究，主要透過訪談法與參與觀察法，分別於台灣與馬來西亞地區蒐集田野資料。主要研究發現為： 一、國籍的差異建構了馬來西亞馬籍與台籍僑生個人與國家（馬來西亞、台灣）關係上的差異，以及來台前教育歷程上的歧異性。來台之馬來西亞僑生中，馬籍僑生多畢業於著重華文教學之獨立中學中體系，而台籍僑生主要來自海外台灣學校。在馬來西亞獨立中學與海外台灣學校就讀的學生面對的是迥異的學習環境與教材、隱藏性課程與參考團體，但在不同因素的考量及作用下，他們不約而同地選擇來台就讀大學，並成為「僑生」。不論是馬籍或台籍僑生，他們對於其所具有之「僑生」身份多是採接受但不認同的態度，不過原因不盡相同。 二、「僑生」身份在台灣社會特殊的歷史脈絡中已逐漸與原始意涵脫鉤，並累積了如學業程度不好、說中文有口音及升學制度中之既得利益者等負面標籤，讓「僑生」成為一個被污名之群體。馬來西亞籍僑生由於其成長及受教背景之故，較易具備外顯的僑生符號（如說中文有口音），容易被辨識為「僑生」，因而常需背負「僑生」所具有的污名。台灣籍僑生因為具有台灣國籍以及講中文沒有口音等，迥異於台灣民眾對於一般僑生之想像，而難以被辨識其「僑生」身分，或其僑生身分較難獲得他人認同而另給予「假僑生」的稱謂。 三、依據自身與情境的特質，馬籍與台籍僑生發展相關策略以避免因「僑生」身份而被污名化，包括諸多規避（passing）行為（如口音轉換、呈現在地之身分認同、避免參與僑生團體）以避免身分暴露、構成強凝聚力之僑生團體以獲取社會支持及建構群體認同等策略。另外，台籍僑生一方面由於不符合社會對「僑生」的刻版印象，另一方面也為避免承受「僑生」身份的污名，往往接受「假僑生」的稱謂，並視其為一「戲謔性」但不具污名的稱呼。 / This study alalyzes the the education processes of Malaysian overseas Chinese students and their reasonings for studying in Taiwan on the one hand, and explores how the difference in nationality (Malaysia vs. Taiwan) affect their life experiences in Taiwan and their attitudes toward the “overseas Chinese student” identity given by the Taiwanese society on the other. The study utilizes qualitative research methods and collects field data (mainly through participant observation and in-depth interviewing techniques) from Taiwan and Malaysia. The major findings are stated as follows: 1. Difference in nationality between Malaysian and Taiwanese Chinese students constructs the divergence in their relations with respective states (Taiwan and Malaysia) and eductation tracking processes prior to their study in Taiwan. Among ethnic Chinese students from Malaysia studying in Taiwan, Malaysian Chinese students mostly graduated from independent high schools while Taiwanese Chinese came from overseas Taiwanese schools. The distinctions in these two schooling systems in the academic melius, teaching materials, hidden curriculums, and reference groups shape the different reasonings to study in Taiwan. For various reasons, these students accept but not necessarily agree on the “overseas Chinese student” identity given by Taiwanese soceity upon their arrival in Taiwan. 2. Under the changing historical context, the identity of “overseas Chinese student” has gradually lost its originally denotation and even become a stigmatized label. Malaysian Chinese students tend to be more easily identified as “overseas Chinese students” due to their more salient outer attributes (such as accent) and thus more likely to be stigmatized. Taiwanese Chinese students (from Malaysia), due to their Taiwanese nationality and Taiwanese accent, are less likely to be seen as “overseas Chinese students.”Even if this identity is disclosed, such identity is often challenged by others because of the misfit with the stereotype of “overseas Chinese student” that exists in the Taiwanese society. As a result, Taiwanes Chinese students from Malaysia are often called “psudo overseas Chinese students.” 3. Both Malaysian and Taiwanese Chinese students from Malaysia develop various strategies to aviod or overcome the possible stigmatization brought by the identity of “overseas Chinese students,” including many “passing” techniques as well as forming proactive and powerful overseas student associations. For Taiwanese Chinese students from Malaysia specifically, they often playfully accept the seemly degrading and yet un-stigmatzied title of “psudo overseas Chinese students” as a way to avoid stigmatization embedded in the identity of “overseas Chinese students.”

In this dissertation, we study the verification of concurrent programs written in the programming language Erlang using infinite-state model-checking. Erlang is a widely used, higher order, dynamically typed, call-by-value functional language with algebraic data types and pattern-matching. It is further augmented with support for actor concurrency, i.e. asynchronous message passing and dynamic process creation. With decidable model-checking in mind, we identify actor communicating systems (ACS) as a suitable target model for an abstract interpretation of Erlang. ACS model a dynamic network of finite-state processes that communicate over a fixed, finite number of unordered, unbounded channels. Thanks to being equivalent to Petri nets, ACS enjoy good algorithmic properties. We develop a verification procedure that extracts a sound abstract model, in the form of an ACS, from a given Erlang program; the resulting ACS simulates the operational semantics of the input. Using this abstract model, we can conservatively verify coverability properties of the input program, i.e. a weak form of safety properties, with a Petri net model-checker. We have implemented this procedure in our tool Soter, which is the first sound verification tool for Erlang programs using infinite-state model-checking. In our experiments, we find that Soter is accurate enough to verify a range of interesting and non-trivial benchmarks. Even though ACS coverability is Expspace-complete, Soter's analysis of these verification problems is surprisingly quick. In order to improve the precision of our verification procedure with respect to recursion, we investigate an extension of ACS that allows pushdown processes: asynchronously communicating pushdown systems (ACPS). ACPS that satisfy the empty-stack constraint (a pushdown process may receive only when its stack is empty) are a popular subclass of ACPS with good decision and complexity properties. In the context of Erlang, the empty stack constraint is unfortunately not realistic. We introduce a relaxation of the empty-stack constraint for ACPS called the shaped stack constraint. Stacks that fit the shape constraint may reach arbitrary heights. Further, a process may execute any communication action (be it process creation, message send or retrieval) whether or not its stack is empty. We prove that coverability for shaped ACPS, i.e. ACPS that satisfy the shaped constraint, reduces to the decidable coverability problem for well-structured transition systems (WSTS). Thus, shaped ACPS enable the modelling and verification of a larger class of message passing programs. We establish a close connection between shaped ACPS and a novel extension of Petri nets: nets with nested coloured tokens (NNCT). Tokens in NNCT are of two types: simple and complex. Complex tokens carry an arbitrary number of coloured tokens. The rules of a NNCT can synchronise complex and simple tokens, inject coloured tokens into a complex token, and eject all tokens of a specified set of active colours to predefined places. We show that the coverability problem for NNCT is Tower-complete, a new complexity class for non-elementary decision problems introduced by Schmitz. To prove Tower-membership, we devise a geometrically inspired version of the Rackoff technique, and we obtain Tower-hardness by adapting Stockmeyer's ruler construction to NNCT. To our knowledge, NNCT is the first extension of Petri nets (belonging to the class of nets with an infinite set of token types) that is proven to have primitive recursive coverability. This result implies Tower-completeness of coverability for ACPS that satisfy the shaped stack constraint.

Das Konzept des Doing Gender geht auf Garfinkels ethnomethodologische Untersuchung der sozialen Konstruktion der Zwei-Geschlechtlichkeit zurück. Die unterschiedlichen Konzeptionen des Doing Gender variieren mit der Interpretation der Omnirelevanz-Annahme und des Garfinkelschen Accountability-Konzepts; ihnen gemein ist, Geschlecht nicht als natürliches oder erworbenes Personenmerkmal zu sehen, sondern als durch Zuschreibung oder mittels sozialer Interaktion hervorgebrachtes.

Harold Garfinkel untersuchte in seiner ethnomethodologischen Studie über Agnes, die er 1967 im Prozess der Geschlechtsumwandlung begleitete, die Praktiken der alltäglichen, interaktiven Produktion des Geschlechts. Das hieraus entstandene Konzept des Doing Gender erkennt Geschlecht nicht als natürlichen Zustand, sondern als in sozialer Interaktion hervorgebrachtes Personenmerkmal.

<p>In this thesis we use the syntactic-semantic method of constructive type theory to give meaning to classical logic, in particular Gentzen's LK.</p><p>We interpret a derivation of a classical sequent as a derivation of a contradiction from the assumptions that the antecedent formulas are true and that the succedent formulas are false, where the concepts of truth and falsity are taken to conform to the corresponding constructive concepts, using function types to encode falsity. This representation brings LK to a manageable form that allows us to split the succedent rules into parts. In this way, every succedent rule gives rise to a natural deduction style introduction rule. These introduction rules, taken together with the antecedent rules adapted to natural deduction, yield a natural deduction calculus whose subsequent interpretation in constructive type theory gives meaning to classical logic.</p><p>The Gentzen-Prawitz inversion principle holds for the introduction and elimination rules of the natural deduction calculus and allows for a corresponding notion of convertibility. We take the introduction rules to determine the meanings of the logical constants of classical logic and use the induced type-theoretic elimination rules to interpret the elimination rules of the natural deduction calculus. This produces an interpretation injective with respect to convertibility, contrary to an analogous translation into intuitionistic predicate logic.</p><p>From the interpretation in constructive type theory and the interpretation of cut by explicit substitution, we derive a full precision contraction relation for a natural deduction version of LK. We use a term notation to formalize the contraction relation and the corresponding cut-elimination procedure.</p><p>The interpretation can be read as a Brouwer-Heyting-Kolmogorov (BHK) semantics that justifies classical logic. The BHK semantics utilizes a notion of classical proof and a corresponding notion of classical truth akin to Kolmogorov's notion of pseudotruth. We also consider a second BHK semantics, more closely connected with Kolmogorov's double-negation translation.</p><p>The first interpretation reinterprets the consequence relation while keeping the constructive interpretation of truth, whereas the second interpretation reinterprets the notion of truth while keeping the constructive interpretation of the consequence relation. The first and second interpretations act on derivations in much the same way as Plotkin's call-by-value and call-by-name continuation-passing-style translations, respectively.</p><p>We conclude that classical logic can be given a constructive semantics by laying down introduction rules for the classical logical constants. This semantics constitutes a proof interpretation of classical logic.</p>

In this thesis we use the syntactic-semantic method of constructive type theory to give meaning to classical logic, in particular Gentzen's LK. We interpret a derivation of a classical sequent as a derivation of a contradiction from the assumptions that the antecedent formulas are true and that the succedent formulas are false, where the concepts of truth and falsity are taken to conform to the corresponding constructive concepts, using function types to encode falsity. This representation brings LK to a manageable form that allows us to split the succedent rules into parts. In this way, every succedent rule gives rise to a natural deduction style introduction rule. These introduction rules, taken together with the antecedent rules adapted to natural deduction, yield a natural deduction calculus whose subsequent interpretation in constructive type theory gives meaning to classical logic. The Gentzen-Prawitz inversion principle holds for the introduction and elimination rules of the natural deduction calculus and allows for a corresponding notion of convertibility. We take the introduction rules to determine the meanings of the logical constants of classical logic and use the induced type-theoretic elimination rules to interpret the elimination rules of the natural deduction calculus. This produces an interpretation injective with respect to convertibility, contrary to an analogous translation into intuitionistic predicate logic. From the interpretation in constructive type theory and the interpretation of cut by explicit substitution, we derive a full precision contraction relation for a natural deduction version of LK. We use a term notation to formalize the contraction relation and the corresponding cut-elimination procedure. The interpretation can be read as a Brouwer-Heyting-Kolmogorov (BHK) semantics that justifies classical logic. The BHK semantics utilizes a notion of classical proof and a corresponding notion of classical truth akin to Kolmogorov's notion of pseudotruth. We also consider a second BHK semantics, more closely connected with Kolmogorov's double-negation translation. The first interpretation reinterprets the consequence relation while keeping the constructive interpretation of truth, whereas the second interpretation reinterprets the notion of truth while keeping the constructive interpretation of the consequence relation. The first and second interpretations act on derivations in much the same way as Plotkin's call-by-value and call-by-name continuation-passing-style translations, respectively. We conclude that classical logic can be given a constructive semantics by laying down introduction rules for the classical logical constants. This semantics constitutes a proof interpretation of classical logic.