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Researches on Automatic Techniques for Specification-Based Testing and Fault Localization
Get PDFThe existing specification-based techniques (SBT) has difficulty in generating an appropriate test suite without the knowledge of code structure to trigger different kinds of unintended behaviours hidden in programs. Symbolic execution, a powerful technique for automating software testing, instead takes advantage of internal code design to detect many types of errors like out of memory and assertion violations. However, it can encounter severe path explosion problem during the exhausted test data generation. Besides, by only using assertions, it may ignore some faulty paths due to not going deep into checking the functional correctness of a path. To address these problems, this research proposes a specification-based incremental testing method with symbolic execution, called SIT-SE, to provide a much more rigorous way to automatically check the functional correctness of all the discovered program paths within limited time. In this method, we introduce theorems instead of assertions for checking path correctness, and describe a Branch Sequence Coverage (BSC) algorithm together with checking levels for guiding a moderate path exploration. The proposed method carefully treats the relationship between a path condition and the specification in a theorem to reduce the monotonous path exploration, whereas traditional symbolic testing methods use assertions that are not sufficient to judge the correctness of a path during the long tedious path exploration. Moreover, we present a strategy of fault localization called TRIACFL with the support of the SIT-SE to give useful hints to pinpoint the faults in a small set of statements. To enrich our methodology of testing used in practice, we also describe a test data generation method that integrates formal specification with a genetic algorithm as supplementary to the SIT-SE for dealing with exceptional cases where some code is not available to testers. We conduct two experiments with the proposed methods, and the results demonstrate that these methods together facilitate an effective automatic bug detection.There are three main contributions in our work. Firstly, we propose a method, SIT-SE, to provide a systematic way to automatically verify the correctness of all the representative program paths by integrating symbolic execution and formal specification. Secondly, we present a fault localization method with the SIT-SE, namely TRIACFL, to provide useful clues for the locations of real faults within a small scale of statements in programs. Thirdly, a test data generation method using the formal specification and a genetic algorithm (GA), is proposed to cope with the situations where the SIT-SE is not applicable.博士(理学)法政大学 (Hosei University
A Research on Learned Image/Video Restoration and Compression for Solving Real-World Degradation
Get PDFThe adage, "A picture is worth a thousand words", has proved the effectiveness of image and video in delivering information. Hence, the Internet becomes wonderful when we can share image/video media with people worldwide in this digital era. It must be more incredible if image/video media can precisely show what we see in real life with our eyes. Unfortunately, due to natural causes (e.g., shooting devices and environments) or artificial causes (e.g., image/video compression sacrificing information to achieve better transmission), the image/video media is not always in the best visual quality which human expects to see (ground-truth), reducing user experience in receiving the information. The loss of an image compared with its ground-truth is called degradation, and the act of solving degradation is called restoration. Even though many advanced techniques have been proposed to restore degraded images/videos, the real-world degradation remains unsolved. Hence, this thesis will dive into and solve specific types of real-world degradation, including (1) artificial degradation in image/video compression and (2) naturally affected degradation in smartphone photo scanning.Regarding (1), we leverage deep learning techniques to solve compression degradation and recover other missing information caused by our effort in reducing compression complexity. Concretely, we sacrifice numerous pixels by down-sampling and color information. It creates a new challenge in compensating for the massively missing information through down-sampling, color removal, and compression. By adopting advanced techniques in computer vision, we propose a specific deep neural network, named restoration-reconstruction deep neural network (RR-DnCNN), to solve Super-Resolution with compression degradation. Furthermore, we also introduce a scheme to compensate for color information with Color Learning and enhance image quality with Deep Motion Compensation for P-frame coding. As a result, our works outperform the standard codec and the previous works in the field.Regarding (2), one solution is to train a supervised deep neural network on many digital images and smartphone-scanned versions. However, it requires a high labor cost, leading to limited training data. Previous works create training pairs by simulating degradation using low-level image processing techniques. Their synthetic images are then formed with perfectly scanned photos in latent space. Even so, the real-world degradation in smartphone photo scanning remains unsolved since it is more complicated due to lens defocus, low-cost cameras, losing details via printing. Besides, locally structural misalignment still occurs in data due to distorted shapes captured in a 3-D world, reducing restoration performance and the reliability of the quantitative evaluation. To address these problems, we propose a semi-supervised Deep Photo Scan (DPScan). First, we present a way to produce real-world degradation and provide the DIV2K-SCAN dataset for smartphone-scanned photo restoration. Also, Local Alignment is proposed to reduce the minor misalignment remaining in data. Second, we simulate many different variants of the real-world degradation using low-level image transformation to gain a generalization in smartphone-scanned image properties, then train a degradation network to learn how to degrade unscanned images as if a smartphone scanned them. Finally, we propose a Semi-Supervised Learning that allows our restoration network to be trained on both scanned and unscanned images, diversifying training image content. As a result, the proposed DPScan quantitatively and qualitatively outperforms its baseline architecture, state-of-the-art academic research, and industrial products in the field.博士(工学)法政大学 (Hosei University
Development of Fencing in Pre-War Japan : Looking back on history with a focus on Hosei University and the Japanese Fencing Federation
Get PDF法政大学体育会40団体（準加盟を含む）のうち、その6割以上が1920～30年代に創立されている。なかでもフェンシング部は1935年、全国に先駆けて「法政大学フェンシング倶楽部」として発足した。当時学生の渋谷忠三が同級生や教授たちに声をかけてクラブを立ち上げ、彼らは日本におけるフェンシングの躍進にも深く関わった。しかしながら、もともと競技人口の少ないスポーツであるためか、フェンシング部の歴史については学内でも注目されることが少なかった。そこで、本稿は法政大学関係者やフェンシング協会の活動に着目しながら、戦前期日本におけるフェンシングの躍進についてまとめた。その過程には学生や教員たちの存在があり、「幻の東京オリンピック」と称される1940年東京大会との関係性を抜きに語ることはできない。法大および協会側の歴史については学内刊行物や部誌、関係者の回想を用い、協会役員が勤務していた新聞社の記事も参照した。また、オリンピックについては豊富な先行研究に依拠しつつ、組織委員会の報告書を参考に、フェンシングに焦点を当てて整理した。渋谷たちの活躍は母校にとどまらなかった。卒業後、自分の会社を事務局にして、慶応義塾大学関係者たちと「大日本アマチュア・フェンシング協会」を発足させ、オリンピック初出場を目標に掲げて競技の普及に尽力した。フェンシングがオリンピック東京大会（1940年）の公式競技から除外される危機を回避できたのはIOCラトゥール会長を含む国内外の関係者による復活運動の結実であった。戦争が進むにつれて、かねてより日本剣道の存在を脅かす競技として認識されていたフェンシングは排撃の対象となったが、敗戦後、復員して来たメンバーが復活を成し遂げた。最後に、フェンシングの復活を見ることなく渋谷が戦死したことは以前より知られていたが、今回、陸軍大将河辺正三の日記を読み解き、戦死の状況が明らかになった。Among 40 teams of Hosei University’s sports association, 60% or more were founded during the period from 1920 to 1930. In particular, the fencing club was founded in 1935 as the first university fencing club in Japan. Chuzo Shibuya, a student at the University then, founded the club with his classmates and teachers and they made great contributions to the development of fencing in Japan. Subsequently, however, as fencing was not enjoyed by many people, the history of the fencing club did not attract much attention even from those inside the university.The author of this document paid attention to the activities of those engaged in the sport at the University and of the Japanese Fencing Federation, and summarized the development of fencing in prewar Japan. Such development was attributable to the efforts made by the students and teachers. Also, the Olympics that was slated to be held in Tokyo in 1940 but later cancelled had much to do with this development. The author referred to the University’s publications related to the history of the fencing club and to the Federation as well as to the written memoirs of those related and the articles published by a newspaper company in which one of the directors of the Federation was working. Also, the author referred to the results of research that had been conducted on the Olympics and checked reports made by the organizing committee that were focused on fencing.Shibuya and other members of the fencing club conducted their activities beyond the framework of normal club activity at a university. After graduating from Hosei University, Shibuya launched a fencing association for amateurs in cooperation with those related to Keio University, and established the secretariat at his own company, aiming to contribute to the popularization of the sport toward the Olympics. As a result of the activities conducted by related individuals in Japan and abroad, including efforts made by Henri de Baillet-Latour, then president of the IOC, fencing was not removed from the official events of the Olympics to be held in Tokyo in 1940. However, as Japan headed into the war, fencing was more strongly regarded as a threat to Japan’s kendo and became a target of attacks. But after Japan was defeated in the war, members of the association returning from the battle fields made contributions toward reviving the sport.It had long been known that Shibuya lost his life in the war without seeing the revival of fencing as a sport, but the author has made new findings about the details of his death by reading the diary written by Masakazu Kawabe, a general in the Imperial Japanese army
EFFECT OF ROLLING AND DISPERSANT ON MECHANICAL PROPERTIES OF CARBON NANOTUBE/ALUMINIUM COMPOSITES
Get PDFIn recent years, carbon nanotube (CNT) has been attractive to be used for reinforcements in metal matrix composites (MMCs) to be applied to structural members because CNT has distinguished characteristics such as lightweight, high elastic modulus, high strength and others. However, wider application of CNT and its composites has not been achieved due to difficulty to disperse CNT in the MMCs to efficiently obtain the expected excellent properties. In this study, CNT was uniformly dispersed using chemical and mechanical treatments, such as an ultrasonic treatment with dispersant in an organic solvent, a dry ball milling and post-sintering hot rolling. CNT/Al composites were consolidated by spark plasma sintering (SPS). The effect of these treatments on state of dispersion of CNT and mechanical properties of the composites was investigated. Microstructures of the composites were observed using a scanning electron microscope (SEM) with EDS, and transmission electron microscope (TEM). The mechanical properties were investigated on Vickers hardness and anisotropic tensile behavior
FABRICATION OF ZIRCONIA/ 304 STAINLESS STEEL FUCTIONALLY GRADED MATERIALS USING CENTRIFUGAL SLURRY METHOD AND SPARK PLASMA SINTERING
Get PDFFunctionally graded materials (FGMs) are multi-phase composites with gradual spatial variations of constituents. FGMs are recognized to have two manners of gradual transition of properties from one side to another side. One is a continuous gradient manner, and another is a stepwise manner. In this study, zirconia (ZrO_2)/ 304 stainless steel (SUS304) FGMs with continuous composition gradient were fabricated by centrifugal slurry methods and spark plasma sintering (SPS). The fabricated samples were investigated on their microstructures and micro-and nano-mechanical properties such as micro Vickers and nanoindentation hardness. In addition, resistance to cyclic thermal shock loadings of the FGMs was investigated. The results demonstrated that controlling of the continuous gradient was possibly achieved using the combination of the centrifugal techniques and SPS. By changing the amount of dispersant, ammonium polycarboxylic acid (PCA), it is possible to fabricate FGMs with different compositional gradation patterns. SUS304-rich FGMs showed superior thermal shock resistance among the fabricated samples
（Translation in Japanese with Translator’s Introduction） Property in Land : Every One’s Right ; Proved in a Lecture Read at the Philosophical Society in Newcastle, on the 8th of Nov. 1775･･･Thomas SPENCE
Get PDF<Research Note> Consideration about Regional Branding of Hard Clam on Sanbanse of Chiba Prefecture, Japan
Get PDF経済のグローバル化が進み，人と物の国際的移動に伴う侵略的外来生物による生物多様性への影響が深刻な問題となっている．千葉県船橋市や東京湾三番瀬の新たな名産品である「三番瀬ホンビノスガイ」は，千葉県が2017年に「千葉ブランド水産物」に認定した水産物であり，外来種としてブランド水産物に認定された初めての事例である．近年，地域経済を活性化させる方策として農林水産物のブランド化が進んでおり，地域ブランドの取り組みとしては以前から評価を得ていたものをさらに高める場合と，無名の産品の名を拡げようとする場合がある．三番瀬ホンビノスガイは，後者である．本稿では，三番瀬をとりまく環境の移り変わりから「三番瀬ホンビノスガイ」を地域ブランドとして官民一体となってPR活動を行った結果、外来種であるホンビノスガイを「千葉ブランド水産物」まで押し上げた背景を考察する
