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Discrete Plane Segmentation and Estimation from a Point Cloud Using Local Geometric Patterns

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International Journal of Automation and computing 2008年第3期5卷 246-256页

作者： Yukiko Kenmochi Lilian Buzer akihiro Sugimoto Ikuko Shimizu Université Paris-Est Laboratoire d'Informatique de l'Institut Gaspard-MongeUMR CNRS 8049 A2SI-ESIEECité DescartesBP 9993162 Noisy-le-Grand CedexFrance Department of Computer Information and Communication SciencesTokyo University of Agriculture and Technology

This paper presents a method for segmenting a 3D point cloud into planar surfaces using recently obtained discretegeometry results. In discrete geometry, a discrete plane is defined as a set of grid points lying between two parallel planes with a small distance, called thickness. In contrast to the continuous case, there exist a finite number of local geometric patterns （LGPs） appearing on discrete planes. Moreover, such an LGP does not possess the unique normal vector but a set of normal vectors. By using those LGP properties, we first reject non-linear points from a point cloud, and then classify non-rejected points whose LGPs have common normal vectors into a planar-surface-point set. From each segmented point set, we also estimate the values of parameters of a discrete plane by minimizing its thickness.

关键词： Discrete plane image segmentation parameter estimation discrete geometry local geometric pattern (LGP)

Properties of garnet-type Li6La3ZrTaO12 solid electrolyte films fabricated by aerosol deposition method

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Progress in Natural Science:Materials International 2017年第3期27卷 350-355页

作者： Ryoji Inada Takayuki Okada akihiro Bando Tomohiro Tojo Yoji Sakurai Department of Electrical and Electronic Information Engineering Toyohashi University of Technology

The garnet-type Li6La3ZrTaO12（LLZT） solid electrolyte films were fabricated by aerosol deposition（AD）***-milled LLZT powder with a cubic garnet structure and a particle size of 1-2 urn was used as raw material and deposited directly on a SUS316L or a glass substrate via impact ***-deposited LLZT film has a cubic garnet structure but contains Li2CO3and *** observation revealed that the film consists of LLZT particles fractured into submicron *** impurity phase formation during AD process was caused by the local heating by the collision between LLZT particles and deposition surface and reaction with *** Li+ion conductivity of LLZT film was estimated to be 0.24 × 10-5S cm-1at room *** conductivity of LLZT film was confirmed to be around 10-12S cm-1,indicating the dominant Li+ion conduction of LLZT film.

关键词： Lithium-ion Garnet Solid electrolyte Thick film Aerosol deposition Ionic conductivity

Exploring the hepatitis C virus genome using single molecule realtime sequencing

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World Journal of Gastroenterology 2019年第32期25卷 4661-4672页

作者： Haruhiko Takeda Taiki Yamashita Yoshihide Ueda akihiro Sekine Department of Omics-based Medicine Center for Preventive Medical ScienceChiba UniversityChiba 260-0856Japan Department of Gastroenterology and Hepatology Graduate School of MedicineKyoto UniversityKyoto 606-8507Japan

Single molecular real-time(SMRT)sequencing,also called third-generation sequencing,is a novel sequencing technique capable of generating extremely long contiguous sequence *** conventional short-read sequencing cannot evaluate the linkage of nucleotide substitutions distant from one another,SMRT sequencing can directly demonstrate linkage of nucleotide changes over a span of more than 20 kbp,and thus can be applied to directly examine the haplotypes of viruses or bacteria whose genome structures are changing in real *** addition,an error correction method(circular consensus sequencing)has been established and repeated sequencing of a single-molecule DNA template can result in extremely high *** advantages of long read sequencing enable accurate determination of the haplotypes of individual viral *** sequencing has been applied in various studies of viral genomes including determination of the full-length contiguous genome sequence of hepatitis C virus(HCV),targeted deep sequencing of the HCV NS5A gene,and assessment of heterogeneity among viral ***,the emergence of multi-drug resistant HCV viruses has become a significant clinical issue and has been also demonstrated using SMRT *** this review,we introduce the novel third-generation PacBio RSII/Sequel systems,compare them with conventional next-generation sequencers,and summarize previous studies in which SMRT sequencing technology has been applied for HCV genome *** also refer to another long-read sequencing platform,nanopore sequencing technology,and discuss the advantages,limitations and future perspectives in using these thirdgeneration sequencers for HCV genome analysis.

关键词： Third generation sequencing PacBio RSII Single molecule real-time sequencing Hepatitis C virus Resistance-associated substitution Nanopore sequencer

CFD Simulation of Pulsation Noise in a Small Centrifugal Compressor with Volute and Resonance Tube

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Journal of Thermal Science 2015年第1期24卷 24-29页

作者： Daich Wakaki Yuta Sakuka Yuzo Inokuchi Kosuke Ueda Nobuhiko Yamasaki akihiro Yamagata Kyushu University IHI Corporation

The rotational frequency tone noise emitted from the automobile turbocharger is called the pulsation noise. The cause of the pulsation noise is not fully understood, but is considered to be due to some manufacturing errors, which is called the mistuning. The effects of the mistuning of the impeller blade on the noise field inside the flow passage of the compressor are numerically investigated. Here, the flow passage includes the volute and duct located downstream of the compressor impeller. Our numerical approach is found to successfully capture the wavelength of the pulsation noise at given rotational speeds by the comparison with the experiments. One of the significant findings is that the noise field of the pulsation noise in the duct is highly one-dimensional although the flow fields are highly three-dimensional.

关键词： Pulsation Tone Noise CFD URANS Centrifugal Compressor Turbocharger Volute

Biomimetic Riblets Inspired by Sharkskin Denticles： Digitizing, Modeling and Flow Simulation

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Journal of Bionic Engineering 2018年第6期15卷 999-1011页

作者： Mariko Miyazaki Yuji Hirai Hiroshi Moriya Masatsugu Shimomura akihiro Miyauchi Hao Liu Hitachi Ltd. 832-2 Horiguchi Hitachinaka Ibaraki 312-0034 Japan Chitose Institute of Science and Technology 758-65 Bibi Chitose Hokkaido 066-8655 Japan Tokyo Medical Dental University 2-3-10 Kanda-Surugadai Chiyodaku Tokyo 101-0062 Japan Chiba University 1-33 Yayoi-cho Inage-ku Chiba 263-8522 Japan

While sharkskin surface roughness in terms of denticle morphology has been hypothesized but remains yet controversial to be capable of achieving turbulent flow control and drag reduction, sharkskin-inspired ＂riblets＂ have been reported to be an effective biomimetic design. Here we address an integrated study of biomimetic riblets inspired by sharkskin denticles by combining 3D digitizing and mod- eling of＂fresh＂ denticles and computational fluid dynamic modeling of turbulent flows on a rough surface with staggered denticles and hound-tooth-patterned grooves. Realistic microstructures of denticles in five shark species of Galapagos, great white, whitetip reef, blacktip reef, and hammerhead sharks were first measured and digitized in three fold：（1） 2D imaging of lubricated sharkskin in a wet state by means of a ＂nano-suit＂ technique with a Field-Emission Scanning Electron Microscope （FE-SEM）; （2） 3D structures of sharkskin denticles with a micro-focus X-ray CT; and （3） single denticles of the five shark species in a 3D manner with 3D-CAD. The denticles at mid-body location in the five species were observed to have a structure of five non-uniform-ridges （herein termed ＂non-uniform grooves＂） with Angles Of Inclination （AOI） ranging over 20° - 32°. Hydrodynamics associated with the unique five-ridge denticles were then in- vestigated through modeling turbulent flow past a denticle-staggered skin surface. We further constructed a biomimetic riblet model inspired by the non-uniform grooves and investigated the hydrodynamic effects of height-to-spacing ratios of mid-ridge and side-ridges. Our results indicate that the morphological non-uniformity in sharkskin denticles likely plays a critical role in passively controlling local turbulent flow and point to the potential of denticle-inspired biomimetic riblets for turbulent-flow control in aquatic vehicles as well as other fluid machinery.

关键词： sharkskin denticles biommetic riblets 3D digitizing computational fluid dynamics

Hepatitis B virus infection and alcohol consumption

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World Journal of Gastroenterology 2017年第15期23卷 2651-2659页

作者： ayako iida-ueno masaru enomoto akihiro tamori norifumi kawada Department of Hepatology Osaka City University Graduate School of Medicine

Hepatocellular carcinoma(HCC) is the most common type of primary liver cancer, and the second most common cause of cancer deaths worldwide. The top three causes of HCC are hepatitis B virus(HBV),hepatitis C virus(HCV), and alcoholic liver disease. Owing to recent advances in direct-acting antiviral agents, HCV can now be eradicated in almost all patients. HBV infection and alcoholic liver disease are expected, therefore, to become the leading causes of HCC in the future. However, the association between alcohol consumption and chronic hepatitis B in the progression of liver disease is less well understood than with chronic hepatitis C. The mechanisms underlying the complex interaction between HBV and alcohol are not fully understood, and enhanced viral replication, increased oxidative stress and a weakened immune response could each play an important role in the development of HCC. It remains controversial whether HBV and alcohol synergistically increase the incidence of HCC. Herein, we review the currently available literature regarding the interaction of HBV infection and alcohol consumption on disease progression.

关键词： Entecavir Genetic factors Hepatocellular carcinoma Interferon

Correlation between the glass-forming ability and activation energy of crystallization for Zr_(75-x)Ni_(25)Al_x metallic glasses

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International Journal of Minerals,Metallurgy and Materials 2013年第5期20卷 445-449页

作者： Yan-hui Li Wei Zhang Chuang Dong Jian-bing Qiang akihiro Makino School of Materials Science and Engineering Dalian University of Technology Institute for Materials Research Tohoku University

The thermal stability and the kinetics of glass transition and crystallization for Zr75-xNi25Alx （x = 8-15） metallic glasses were investigated using differential scanning calorimetry （DSC） under continuous heating conditions. The apparent activation energy of glass transition rises monotonously with the A1 content increasing; the activation energy of crystallization increases with A1 changing from 8at% to 15at%, and then decreases with A1 further up to 24at%, which exhibits a good correlation to the thermal stability and the glass-forming ability （GFA）. The Zr60Ni25A115 metallic glass with the largest supercooled liquid region and GFA possesses the highest activation energy of crystallization. The relation between the thermal stability, GFA and activation energy of crystallization was discussed in terms of the primary precipitated phases.

关键词： metallic glass thermal stability glass-forming ability crystallization kinetics activation energy

Improvement of the physical properties of poly(methyl methacrylate) by copolymerization with N-pentafluorophenyl maleimide; zero-orientational and photoelastic birefringence polymers with high glass transition temperatures

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Science China Chemistry 2012年第5期55卷 850-853页

作者： TAGAYA akihiro LOU LiPing IDE Yoko KOIKE Yasuhiro OKAMOTO Yoshiyuki Keio Photonics Research Institute Keio University E-building Shin-Kawasaki Town Campus 7-1 Shin-Kawasaki Saiwai-ku Kawasaki 212-0032 Japan Faculty of Science and Technology Keio University 3-14-1 Hiyoshi Kohoku-ku Yokohama 223-8522 Japan Polymer Research Institute Polytechnic Institute of NYU 6 MetroTech Center Brooklyn New York 11201 USA

Copolymers of N-pentafluorophenyl maleimide (PFPMI) with methyl methacrylate (MMA) were synthesized by a free radical initiator, such as AIBN. The refractive indexes of the copolymers remained nearly constant (1.4970 at 532 nm) regardless of the polymer composition. These copolymers also showed high thermal stability. The orientational and photoelastic birefringence of the copolymers obtained were measured. Since both of the orientational and photoelastic birefringences of PMMA are negative whereas poly(PFPMI) exhibits positive, thus we have obtained nearly zero orientational and photoelastic birefringence polymers when the ratios of MMA/PFPMI were 91.8/8.2 and 97.0/3.0 mol%, respectively. Based on the experimental data, the ratios of MMA/PFPMI for zero birefringence were determined to be 88.9/11.1 and 93.8/6.2 mol% for orientational and photoelastic birefringence, respectively. The Tgs of corresponding copolymers were estimated to be 128 and 122 ℃.

关键词： N-pentafluorophenyl maleimide copolymers orientational birefringence photoelastic birefringence

Construction of Design Guidelines for Optimal Automotive Frame Shape Based on Statistical Approach and Mechanical Analysis

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Computer Modeling in Engineering & Sciences 2021年第8期128卷 731-742页

作者： Masanori Honda Chikara Kawamura Isamu Kizaki Yoichi Miyajima akihiro Takezawa Mitsuru Kitamura Mazda Motor Corporation 3-1 ShinchiFuchu-choAki-gunHiroshima730-8670Japan Department of Applied Mechanics and Aerospace Engineering School of Fundamental Science and EngineeringWaseda University3-4-1 OkuboShinjuku-kuTokyo169-8555Japan Division of Advanced Science and Engineering Graduate School of Advanced Science and EngineeringHiroshima University1-4-1 KagamiyamaHigashihiroshimaHiroshima739-8527Japan

A body frame composed of thin sheet metal is a crucial structure that determines the safety performance of a *** a correct weight and high-performance automotive body is an emerging engineering *** improve the performance of the automotive frame,we attempt to reconstruct its design criteria based on statistical and mechanical *** first,a fundamental study on the frame strength is conducted and a cross-sectional shape optimization problem is developed for designing the cross-sectional shape of an automobile frame having a very high mass efficiency for *** optimization is carried out using the nonlinear finite element method and a meta-modeling-based genetic *** analysis of the obtained set of optimal results is performed to identify the dominant design variables by employing the smoothing spline analysis of variance,the principal component analysis,and the self-organizing map *** relationship between the cross-sectional shape and the objective function is also analyzed by hierarchical clustering.A design guideline is obtained from these statistical approach results.A comparison between the statistically obtained design guideline and the conventional one based on the designers’experience is performed based on mechanical interpretation of the optimal cross-sectional ***,a mechanically reasonable new general-purpose design guideline is proposed for the cross-sectional shape of the automotive frame.

关键词： Automotive structure shape optimization data mining statistical approach crash-performance