Concurrent software executes multiple threads or processes to achieve high performance. However, concurrency results in a huge number of different system behaviors that are difficult to test and verify. The aim of this dissertation is to develop new methods and tools for modeling and analyzing concurrent software systems at design and code levels. This dissertation consists of several related results. First, a formal model of Mondex, an electronic purse system, is built using Petri nets from user requirements, which is formally verified using model checking. Second, Petri nets models are automatically mined from the event traces generated from scientific workflows. Third, partial order models are automatically extracted from some instrumented concurrent program execution, and potential atomicity violation bugs are automatically verified based on the partial order models using model checking. Our formal specification and verification of Mondex have contributed to the world wide effort in developing a verified software repository. Our method to mine Petri net models automatically from provenance offers a new approach to build scientific workflows. Our dynamic prediction tool, named McPatom, can predict several known bugs in real world systems including one that evades several other existing tools. McPatom is efficient and scalable as it takes advantage of the nature of atomicity violations and considers only a pair of threads and accesses to a single shared variable at one time. However, predictive tools need to consider the tradeoffs between precision and coverage. Based on McPatom, this dissertation presents two methods for improving the coverage and precision of atomicity violation predictions: 1) a post-prediction analysis method to increase coverage while ensuring precision; 2) a follow-up replaying method to further increase coverage. Both methods are implemented in a completely automatic tool.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第23403号 / 理博第4738号 / 新制||理||1679(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 中家 剛, 准教授 田島 治, 准教授 成木 恵 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Många gånger händer det att eleverna inte syns tillräckligt för fritidshemslärare, det är då det sker kränkande handlingar utförda av andra elever. Den fysiska, psykiska och dolda mobbningen går obemärkt och det drabbar inte bara den utsatte utan det drabbar hela samhället. Syfte i denna studie är att undersöka hur fritidshemslärare arbetar förebyggande mot mobbning och kränkningar i sina verksamheter. Vi jämför två olika skolornas förebyggande arbete mot kränkning och mobbning, den ena med en likabehandlingsplan mot mobbning och kränkande behandling och den andra med en Olweus antimobbningsprogram. Vi vill undersöka i vilken utsträckning och på vilket sätt detta påverkar fritidshemlärarnas arbete gentemot mobbning och kränkande handling som finns i respektive skolor Undersökningen kommer att belysas på olika sätt genom att intervjua både fritidshemslärare, elever och respektive skolors rektorer för att få en bättre förståelse och en bredare perspektiv för undersökningen. Resultatet och diskussionen visar bland annat att fritidshems lärarnas engagemang, närvaro och delaktighet kan vara avgörande i förebyggande syfte mot mobbningen. / Many times, it happens that the students are not visible enough to after-school teachers, this is when abusive acts are performed by other students. The physical, mental, and hidden bullying goes unnoticed, and it not only affects the victim, but it affects the whole society. The purpose of this study is to investigate how after-school center teachers work to prevent bullying and abuse in their activities. We compare two different schools' prevention work against abuse and bullying, one with an equal treatment plan against bullying and abusive treatment and the other with an Olweus anti-bullying program. We want to investigate to what extent and in what way this affects the after-school teachers' work towards bullying and abusive action that exists in each school. a broader perspective for the study. The results and the discussion show, among other things, that the after-school teacher ‘s commitment, presence and participation can be decisive in the preventive purpose against bullying.

abstract: When consumers find that something critically out of the ordinary has occurred, they direct attention to evaluate such a critical incident more closely. The results of this evaluation may put consumers on a switching path or it might lead them to engage in unfavorable behaviors from the perspective of the organization, such as engaging in negative word-or-mouth online. The negative consequences of some product (goods or services) failures go beyond simple product attribute defects, leading customers to terminate the relationship with the organization. This dissertation, which is composed of three essays, investigates how consumers engage in negative word-of-mouth on social media channels in response to their various product failures and explores an important relationship event of betrayal, which can be triggered by certain product failures. It investigates how betrayal is perceived by customers and influences a range of their behaviors across business-to-consumer and business-to-business contexts. / Dissertation/Thesis / Doctoral Dissertation Business Administration 2019

We present a first measurement of time-dependent CP-violation in B0 → D∗∓ ρ± , where D∗∓ → D0 π. The analysis was performed using the final Belle dataset containing 772 × 106 B ¯B pairs collected at the KEKB e+ e− collider. Three D0 decay modes are analyzed, K∓ π± , K∓ π± π0 , and K∓ π± π∓ π± . Since the studied decay is a scalar → vector vector decay, three helicity configurations are present. Exploiting the helicity configura- tions via angular analysis, the time-dependent CP-violation parameters encoding 2ϕ1 +ϕ3 are obtained from the fit. 1

Background:  Leader member exchange (LMX) theory focuses on the different associations established by the leaders with their followers through a system of exchanges (high quality and low exchanges), whereas a psychological contract is a tacit agreement between the employer and employee and comprises of employee's beliefs regarding the mutual obligations between the employee and an employer. Since an organization communicates and negotiates through its representatives which indicates people in managerial positions, it is meaningful to draw that the relationship quality between employee and their supervisors may affect the tacit agreement between the employee and organization. Though prior integration of Leader Member Exchange theory and Psychological contract has established the link between these two area of literature, as well as LMX dimensions to Psychological contract fulfilment, there is no empirical study taken place in Asia where Anand, Hu, Liden and Vidyarthi (2011) once observed that LMX and its dimensions may operate differently in more collectivistic and higher power distance cultures. Therefore, this research aims to examine the two main aspects of literature in one of the leading construction management of Asia located in Vietnam.   Research questions: Does LMX improve psychological contracts between the organization and the employees? Sub-research question: What is the effect of LMX dimensions on psychological contract fulfilment? Is there any right mix of LMX dimensions in the organization that positively affects the psychological contract?   Purpose: The purpose of this study is to examine the interaction effects of leader-member exchange (LMX) and its dimensions on psychological contracts in one specific organization, in other words, it investigates to answer if the different quality exchanges between the leaders/managers with employees support to enhance better mutual obligations between them and give negative or positive effects to the psychological contracts. Secondly, it figures out what exactly is the effect of LMX dimensions on psychological contract fulfilment. Practically, it is to help the researchers and practitioners recognize the increasingly important role of psychological contract which is normally unwritten in formal contract but otherwise gives huge negative influence which results in losing employee’s retention and loyalty. Accordingly, by generating “leader-member exchange” more effectively, the leaders will distribute and/or exchange resources toward the employees better which results in better employee retention and talent management strategies, directly contributing to the organization’s long term sustainable development.   Theoretical framework:  Articles were used for this thesis were meticulously chosen, focusing on reliable sources and quality content that cover the theoretical background of both main research area of Psychological contracts and Leader-Member Exchange during their historical research until recent. Particular information of the empirical organization and the related industry were brought from the organization and related reports and professional analysis from industry experts.   Method: This is a cross-sectional study whose methodology choice is a Mixed methods research which inquires the involvement of both quantitative and qualitative data, integrating these two forms of data with narrative analysis. The data was collected from a construction management organization consists of 385 employees. It adopted interpretivism philosophy in order to create new, richer understandings and interpretations of issues related to social worlds and context, in particular exploring the issue of whether LMX theory have an influence on psychological contracts fulfilment. It follows a deductive reasoning as its main approach.   Discussion and Conclusion: Based on the results of respondents’ surveys and the interpretation of the attendants from Focus Group, the discussion was structured and analyzed in line with the structure of the theoretical framework. The study reveals that the psychological contract fulfillment depends not only on the right combination of LMX dimensions and the concern of those most important dimensions but also the distinct characteristics of the organization which concern about their organization behavior and industry features. The study also provides solutions to leaders in order to overcome the problems associated with LMX that can lead to psychological contract breach.   Originality/Value – This is the first study that focuses on examining the effect of LMX and its dimensions on psychological contract fulfilment in an Asian country.

This master thesis attempts to contribute to the existing earnings management literature by examining whether tax avoidance incentives affect opportunistic accounting choices in distress conditions. To address this issue, it investigates 2668 companies in the quarters around breach of debt covenant spanning from 1996 to 2006. This allows to analyze two distress scenarios: first, whether the companies having the opportunity to minimize tax expenses and thus improve their financial stability, would deliberately switch from engaging in aggressive upwards real earnings management to tax considerations to mitigate the potential consequences of technical default; second, whether the companies facing increased lender's scrutiny after subsequent violation are compelled to switch by the creditor. The results indicate that tax considerations do not deter misreporting in the quarters around debt covenant violation. This thesis further provides evidence against the debt covenant hypothesis: the companies in the analyzed sample engaged in negative revenue manipulation in the quarters of new breach of debt covenant and in the quarters in which the firms remained in violation. In additional analysis, it was found that the above relationship is more prominent for the companies exhibiting poor financial performance.

This study examines whether financial analysts produce larger amounts of research output and whether their research is more valuable for investors following a debt covenant violation (DCV, hereafter). After a DCV, investor uncertainty about firm value and information asymmetry among stakeholders likely increases. It is therefore difficult for investors to assess firm prospects, resulting in increased demand for firm-specific information. Sell-side analysts, as sophisticated information intermediaries, are skilled at gathering and processing information; thus they are well-suited to provide more research output in response to increased investor demand. I predict and find that equity analysts provide a larger amount of research, proxied by recommendation revisions and earnings forecast revisions, after a DCV. I also document an incremental association between a DCV and analyst research production for firms with less financial flexibility, firms with low institutional ownership, and firms covered by more experienced analysts. In addition, I find evidence that analyst research becomes more valuable and that uncertainty-adjusted analyst forecast errors decrease following a DCV. These results suggest that a change in a firm’s information environment associated with a DCV has significant influence on investors and equity analysts besides the economic consequences documented in prior literature.

This thesis is devoted to studies of the proper decay-time resolution function and particle decay vertex reconstruction tools, their applicability and role in the studies of time-dependent CP violation at the Belle II experiment. A positive effect of beam spot constraints and new beam spot calibration on the vertex reconstruction precision is seen via MC/data comparison. The core part of the work focuses on studying universality of the time resolution function across nine different neutral and charged B-meson decay channels. The possibility to use a single form of this function for all studied channels is demon- strated and supported by the consistency between the lifetime values used for simulation and obtained as results of the decay time difference fit. 1

Concurrency bugs are extremely hard to detect due to huge interleaving space. They are happening in the real world more often because of the prevalence of multi-threaded programs taking advantage of multi-core hardware, and microservice based distributed systems moving more and more applications to the cloud. As the most common non-deadlock concurrency bugs, atomicity violations are studied in many recent works, however, those methods are applicable only to single-variable atomicity violation, and don't consider the specific challenge in distributed systems that have both pessimistic and optimistic concurrency control. This dissertation presents a tool using model checking to predict atomicity violation concurrency bugs involving two shared variables or shared resources. We developed a unique method inferring correlation between shared variables in multi-threaded programs and shared resources in microservice based distributed systems, that is based on dynamic analysis and is able to detect the correlation that would be missed by static analysis. For multi-threaded programs, we use a binary instrumentation tool to capture runtime information about shared variables and synchronization events, and for microservice based distributed systems, we use a web proxy to capture HTTP based traffic about API calls and the shared resources they access including distributed locks. Based on the detected correlation and runtime trace, the tool is powerful and can explore a vast interleaving space of a multi-threaded program or a microservice based distributed system given a small set of captured test runs. It is applicable to large real-world systems and can predict atomicity violations missed by other related works for multi-threaded programs and a couple of previous unknown atomicity violation in real world open source microservice based systems. A limitation is that redundant model checking may be performed if two recorded interleaved traces yield the same partial order model.