京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20986号 / 医博第4332号 / 新制||医||1027(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 富樫 かおり, 教授 羽賀 博典, 教授 別所 和久 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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Test coverage is an important parameter of analyzing how well the product is being tested in any domain within the IT industry. Unit testing is one of the important processes that have gained even more popularity with the rise in Test driven development (TDD) culture.This degree project, conducted at NASDAQ Technology AB, analyzes the existing unit tests in one of the products, and compares various coverage models in terms of quality. Further, the study examines the factors that affect code coverage, presents the best practices for unit testing, and a proven test process used in a real world project.To conclude, recommendations are given to NASDAQ based on the findings of this study and industry standards. / Testtäckning är en viktig parameter för att analysera hur väl en produkt är testad inom alla domäner i IT-industrin. Enhetstestning är en av de viktiga processerna som har ökat sin popularitet med testdriven utveckling. Detta examensarbete, utfört på NASDAQ Technology AB, analyserar de befintliga testen i en av produkterna, och jämför olika kvalitetsmodeller. Vidare undersöker undersökningen de faktorer som påverkar koddekning, presenterar de bästa metoderna för enhetstestning och en beprövad testprocess som används i ett verkligt världsprojekt. Avslutningsvis ges rekommendationer till NASDAQ baserat på resultaten från denna studie och industristandarder.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24219号 / 工博第5047号 / 新制||工||1788(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 藤井 聡, 教授 山田 忠史, 准教授 QURESHI Ali Gul / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Prototype pollution is a vulnerability in JavaScript and other prototype-based languages that allows malicious actors to inject a property into an object’s prototype. The injected property can subsequently trigger gadgets - source code sections that use the properties in sensitive locations. Gadgets can lead to various exploits, including denial-of-service, data exfiltration, and arbitrary code execution (ACE). Current research focuses primarily on the detection of pollution, while only a few discuss gadget detection. Those that do either propose detection solutions for browser-side applications or selected frameworks. This thesis aims to answer how prototype pollution affects modern server-side applications built on the Node.js framework. We propose a system that can automatically detect potential prototype pollution gadgets in Node.js applications. We utilize dynamic taint tracking to find flows from polluted prototypes to exploitable functions. Our system consists of multiple distinct runs. A first run analyzes a program without changing the control-flow to avoid premature termination through exceptions and program crashes. In subsequent runs, the system selectively changes conditionals to increase coverage. Based on our methodology, we implement Dasty, a performant dynamic taint analysis for prototype pollution gadgets built on NodeProf and the Truffle Instrumentation Framework. Dasty can automatically analyze third-party packages by utilizing their test suites. We use our implementation to analyze the 5000 most depended upon npm packages and verify the resulting flows systematically, focusing on ACE and similar high-profile vulnerabilities. Through the analysis, we identify 16 new gadgets in packages used by thousands of applications. Our results suggest that prototype pollution can lead to serious security issues in many modern applications. / Prototype pollution är en sårbarhet i JavaScript och andra prototypbaserade språk som tillåter skadliga aktörer att injicera en egenskap i ett objekts prototype. Den prototype som blivit komprometterad kan därefter utlösa gadgets - delar av kod som använder egenskaperna på känsliga positioner. Gadgets kan leda till olika exploiteringar, inklusive denial-of-service, dataexfiltrering och arbitrary code execution (ACE). Aktuell forskning fokuserar främst på detektion av prototype pollution, medan endast ett fåtal diskuterar detektion av gadgets. De som gör det föreslår antingen detekteringslösningar för applikationer på webbläsarnivå eller enskilda ramverk. Detta examensarbete syftar till att svara på hur prototype pollution påverkar moderna applikationer på serversidan byggda med ramverket Node.js. Vi föreslår ett system som automatiskt kan upptäcka potentiella prototype pollution gadgets i Node.js-applikationer. Vi använder dynamic taint tracking för att hitta flöden från injicerade prototyper till exploateringsbara funktioner. Vårt system består av flera distinkta körningar. En första körning analyserar ett program utan att ändra kontrollflödet för att undvika för tidig terminering p.g.a. exceptions och programkrascher. I efterföljande körningar ändrar systemet selektivt villkoren för att öka täckningen. Baserat på vår metodik implementerar vi Dasty, en snabb dynamic taint analysis för prototype pollution gadgets byggda på NodeProf och Truffle Instrumentation Framework. Dasty kan automatiskt analysera tredjepartspaket genom att använda deras testramverk. Vi använder vår implementering för att analysera de 5000 mest npm-beroende paketen och verifiera de resulterande flödena systematiskt, med fokus på ACE och liknande högprofilerade sårbarheter. Genom analysen identifierar vi 16 nya gadgets i paket som används av tusentals applikationer. Våra resultat tyder på att prototype pollution kan leda till allvarliga säkerhetsproblem i många moderna applikationer.

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Governments in many counties are taking measures to promote electric vehicles. An important strategy is to build enough charging infrastructures so as to alleviate drivers’ range anxieties. To help the governments make plans about the public charging network, we propose a multi-stage stochastic integer programming model to determine the locations and capacities of charging facilities over finite planning horizons. We use the logit choice model to estimate drivers’ random choices towards different charging stations nearby. The objective of the model is to minimize the expected total cost of installing and operating the charging facilities. Two simple algorithms are designed to solve this model, an approximation algorithm and a heuristic algorithm. A branch-and-price algorithm is also designed for this model, and some implementation details and improvement methods are explained. We do some numerical experiments to test the efficiency of these algorithms. Each algorithm has advantages over the CPLEX MIP solver in terms of solution time or solution quality. A case study of Oakville is presented to demonstrate the process of designing an electric vehicle public charging network using this model in Canada. / Thesis / Master of Science (MSc)

A new concept of current sensor reduction technique called multi-branch current sensing technique (MCST) is proposed in this dissertation. In the proposed current sensing method, one more branch currents are simultaneously measured several times in a single switching cycle by using a single current sensor. After that, the current reconstruction algorithm is applied to obtain all phase currents information. Compared to traditional single current sensor techniques (SCSTs), the proposed method samples the output of the current sensor regularly, and the current sensing dead-zone is dramatically reduced. Since the current sampling is performed periodically, its implementation using a digital controller is extremely simple. Moreover, the periodical dead-zone and the dead-zone near the origin of the voltage vector space which have been a big problem in the existing methods can be completely eliminated. Accordingly, there is no need to have a complicated vector reconfiguration or current estimation algorithm. The proposed MCST also takes the advantages of a SCST such as reduced cost and elimination of the sensor gain discrepancy problem in the multiple current sensor method. The fundamental concept, implementation issues, and limitation of the proposed MCST are described based on three-phase systems first. After that, the proposed MCST is adopted to two-phase inverters and multi-phase dc-dc converters with little modifications. Computer simulations and hardware experiments have been conducted for a three-phase boost converter, a three-phase motor drive system, a two-phase two-leg inverter, a two-phase four-leg inverter with bipolar modulation, a two-phase four-leg inverter with unipolar modulation, and a four-phase dc-dc converter applications. From the simulations and the experimental results, the feasibilities of the proposed method mentioned above are fully verified. / Ph. D.

Today's commercial rapid prototyping systems (i.e., solid freeform fabrication, layered manufacturing) rely on human intervention to load and unload build jobs. Hence, jobs are processed subject to both the machine's and the operator's schedules. In particular, first-in-first-out (FIFO) queuing of such systems will result in machine idle time whenever a build job has been completed and an operator is not available to unload that build job and start up the next one. These machine idle times can significantly affect the system throughput, and, hence, the effective cost rate. This thesis addresses this problem by rearranging the job queue to minimizing the machine idle time, subject to the machine's and operator's schedules. This is achieved by employing a general branch-and-bound search method, that, for efficiency, reduces the search space by identifying contiguous sequences and avoiding reshuffling of those sequences during the branching procedure. The effectiveness of this job scheduling optimization has been demonstrated using a sequence of 30 jobs extracted from the usage log for the FDM 1600 rapid prototyping system in the Department of Mechanical Engineering at Virginia Tech. / Master of Science