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External defects and severity level evaluation of potato using single and multispectral imaging in near infrared region Author links open overlay panel

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Information Processing in Agriculture 2024年第1期11卷 80-90页

作者： Dimas Firmanda Al Riza Slamet Widodo Kazuya Yamamoto Kazunori Ninomiya Tetsuhito Suzuki yuichi ogawa Naoshi Kondo Laboratory of Biosensing Engineering Graduate School of AgricultureKyoto UniversityKitashirakawaKyoto 6068267Japan Department of Biosystems Engineering Faculty of Agricultural TechnologyUniversitas BrawijayaJl.VeteranMalang 65145Indonesia Department of Mechanical and Biosystem Engineering Bogor Agricultural UniversityJl.Raya Darmaga Kampus IPB DarmagaBogor 16680Indonesia Technology Development Department Shibuya Seiki Co.Ltd.66Takaoka-choMatsuyamaEhime 7918036Japan

Non-invasive potato defects detection has been demanded for sorting and grading *** on the classification of the defects has been available,however,investigation on the severity level calculation is *** the detection of the common scab,it has been found that imaging in the infrared region provide an interesting characteristic that could distinguish defected area to normal ***,investigations on this wavelength range is interesting to add more knowledge and for *** this research,the multispectral image has been obtained and investigated especially at three wavelengths(950,1150,1600 nm).Image pre-processing and pseudo-color conversion techniques were explored to enhance the contrast between defects,normal background skin area and soil *** show that external defects,such as common scab and some mechanical damage types,appear brighter in the near infrared region,especially at 1600 nm against the normal skin *** has been found that pseudo-color images conversion provides more information regarding type if surface characteristics compared to grayscale single *** segmentation using pseudo-color images after multiplication operation pre-processing could be used for common scab and mechanical damage detection excluding soil deposits with a Dice Sorensen coefficient of *** addition,image segmentation using single image at 1600 nm shown relatively better results with Dice Sorensen coefficient of 0.72 with note that thick soil deposits will also be *** severity level evaluation had an R2 correlation of 0.84 against standard measurements of severity.

关键词： Multispectral imaging Pseudo-color Common scab External defects Near infrared

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Static and dynamic evaluations of acoustic positioning system using TDMA and FDMA for robots operating in a greenhouse

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International Journal of Agricultural and Biological Engineering 2022年第5期15卷 28-33页

作者： Lok Wai Jacky Tsay Tomoo Shiigi Xunyue Zhao Zichen Huang Keiichiro Shiraga Tetsuhito Suzuki yuichi ogawa Naoshi Kondo Laboratory of Bio-Sensing Engineering Division of Environmental Science and TechnologyGraduate School of AgricultureKyoto UniversityKyoto 606-8502Japan Department of Ocean Mechanical Engineering National Fisheries UniversityShimonoseki 759-6595Japan

Acoustic positioning system has great potential to be applied in a greenhouse due to its centimeter-level accuracy,low cost,and ability of extensive greenhouse *** Spectrum Sound-based local positioning system(SSSLPS)was proposed to be a navigation tool for multiple agricultural robots by the authors'research ***,to increase the system capacity for positioning multiple robots in a greenhouse,the near-far problem caused by the interference between speakers needs to be *** use of different access methods,Time Division Multiple Access(TDMA)or Frequency Division Multiple Access(FDMA),is essential in the SSSLPS system for solving the near-far *** static positioning in a greenhouse was first evaluated by setting different parameters to determine the optimal signal setting for a dynamic *** that,the moving robot tests were added with a motion capture system and tested the performance of TDMA and *** results demonstrated that TDMA can be used in a stationary sound-based positioning system with 12.2 mm accuracy,but it has a time delay problem in dynamic positioning.A simulation was designed to mimic the position error increases with different moving *** FDMA has the sound damping problem in high-frequency regions creating a peak detection issue,it achieved a higher accuracy with an average position error of 62.1 mm compared to 180.3 mm of *** study shows that the TDMA method is suitable for static measurements,while the FDMA method is suitable for measuring dynamic objects and controlling mobile robots.

关键词： greenhouse robots positioning system near-far problem TDMA FDMA

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Robot assisted anatomical liver resection is safe for patient with hepatocellular carcinoma underlying Fontan-associated liver disease

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Hepatobiliary & Pancreatic Diseases International 2025年第1期24卷 111-113页

作者： O˘guzhan¸S al Katsunori Sakamoto Kei Tamura Masahiko Honjo Yusuke Nishi Naotake Funamizu Kohei ogawa Yasutsugu Takada Department of Hepato-Biliary-Pancreatic and Breast Surgery Ehime UniversityEhime University Graduate School of Medicine454 KouShitsukawaToonEhime 791-0295Japan Department of General Surgery Istanbul UniversityIstanbul Faculty of MedicineistanbulTürkiye

Fontan operation is indicated in a single ventricle congenital heart disease which creates a shunt between superior vena cava and pulmonary arteries leading to increased pressure in central venous system and congestive hepatopathy,namely,Fontan-associated liver disease(FALD)[1].Recently,the long-term prognosis after Fontan operation has been improving and the number of patients diagnosed with hepatocellular carcinoma(HCC)arising from FALD is increasing[1].There are several publications on the safety of laparoscopic,conventional surgery and interventional radiological modalities in FALD-HCC patients[2-5].However,there are no reports regarding the robotic hepatectomy for the FALD-HCC *** was the first report showing the safety of robotic anatomical hepatectomy in FALD-HCC patients.

关键词： Fontan hepatocellular liver

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Visual localization for asteroid touchdown operation based on local image features

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Astrodynamics 2020年第2期4卷 149-161页

作者： Yoshiyuki Anzai Takehisa Yairi Naoya Takeishi yuichi Tsuda Naoko ogawa The University of Tokyo Tokyo113-8654Japan RIKEN Center for Advanced Intelligence Project Tokyo103-0027Japan Japan Aerospace Exploration Agency Sagamihara252-5210Japan

In an asteroid sample-return mission,accurate position estimation of the spacecraft relative to the asteroid is essential for landing at the target *** the missions of Hayabusa and Hayabusa2,the main part of the visual position estimation procedure was performed by human operators on the Earth based on a sequence of asteroid images acquired and sent by the *** this approach is still adopted in critical space missions,there is an increasing demand for automated visual position estimation,so that the time and cost of human intervention may be *** this paper,we propose a method for estimating the relative position of the spacecraft and asteroid during the descent phase for touchdown from an image sequence using state-of-the-art techniques of image processing,feature extraction,and structure from *** apply this method to real Ryugu images that were taken by Hayabusa2 from altitudes of 20 km-500 *** is demonstrated that the method has practical relevance for altitudes within the range of 5-1 *** result indicates that our method could improve the efficiency of the ground operation in the global mapping and navigation during the touchdown sequence,whereas full automation and autonomous on-board estimation are beyond the scope of this ***,we discuss the challenges of developing a completely automatic position estimation framework.

关键词： visual navigation structure from motion asteroid touchdown Hayabusa2

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Ground-based low altitude hovering technique of Hayabusa2

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Astrodynamics 2020年第4期4卷 331-347页

作者： Yuya Mimasu Kent Yoshikawa Go Ono Naoko ogawa Fuyuto Terui Yuto Takei Takanao Saiki yuichi Tsuda Institute of Space and Astronautical Science Japan Aerospace Exploration AgencySagamihara 252-5210Japan

The asteroid explorer Hayabusa2 carries multiple rovers and separates them to land on an asteroid *** of these rovers,called MASCOT,was developed under the international cooperation between the Deutsches Zentrum f¨ur Luft-und Raumfahrt and the Centre National d’Etudes *** rover was designed to be separated to land and perform several missions on an asteroid *** support these missions,the mother ship Hayabusa2 must separate this rover at a low altitude of approximately 50 m and hover at approximately 3 km after separation to achieve are liable communication link with *** the on-board guidance,navigation,and control(GNC)does not have an autonomous hovering function,this hovering operation is performed by ground-based *** paper introduces the GNC operation scheme for this hovering operation and reports on its flight results.

关键词： Hayabusa2 MASCOT low altitude hovering guidance,navigation,and control(GNC)

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Design and flight results of GNC systems in Hayabusa2 descent operations

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Astrodynamics 2020年第2期4卷 105-117页

作者： Go Ono Fuyuto Terui Naoko ogawa Yuya Mimasu Kent Yoshikawa Yuto Takei Takanao Saiki yuichi Tsuda Japan Aerospace Exploration Agency Sagamihara252-5210Japan

Hayabusa2 is a Japanese sample return mission from the near-Earth asteroid *** Hayabusa2 spacecraft was launched on December 3,2014,and reached the asteroid on June 27,*** remained there until November 13,2019 for in situ observation and soil sample collection and will return to the Earth in November or December *** its stay at the asteroid,Hayabusa2 performed descent operations 16 *** paper presents an overview of a guidance,navigation,and control method used in such descent *** method consists of on-board and on-ground guidance systems to control the spacecraft and an image-based navigation technique that uses a shape model and ground control points of the *** results in the first touchdown operation are shown as an example,which demonstrate that the method showed a good performance overall and contributed to the success of the mission.

关键词： small body exploration astrodynamics guidance navigation control

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Guidance, navigation, and control of Hayabusa2 touchdown operations

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Astrodynamics 2020年第4期4卷 393-409页

作者： Fuyuto Terui Naoko ogawa Go Ono Seiji Yasuda Tetsuya Masuda Kota Matsushima Takanao Saiki yuichi Tsuda Institute of Space and A stronautical Science Japan A erospace Exploration AgencyKanagawa 252-5210Japan The 3nd Space Technology Department Space System DirisionNEC CorporationTokyo 183-8501Japan

Hayabusa2 is a Japanese sample return mission from the asteroid *** Hayabusa2 spacecraft was launched on 3 December 2014 and arrived at Ryugu on 27 June *** stayed there until December 2019 for in situ observation and soil sample collection,and will return to the Earth in November or December *** the stay,the spacecraft performed the first touchdown operation on 22 February 2019 and the second touchdown on 11 July 2019,which were both completed *** the surface of Ryugu is rough and covered with boulders,it was not easy to find target areas for *** were several technical challenges to overcome,including demanding guidance,navigation,and control accuracy,to realize the touchdown *** this paper,strategies and technical details of the guidance,navigation,and control systems are *** flight results prove that the performance of the systems was satisfactory and largely contributed to the success of the operation.

关键词： small body exploration touchdown astrodynamics guidance navigation control

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Estimations of the Maximum Tangential Velocity V_(θm) in the Vortex Core Region and also the Mean Rotational Velocity V_(oi) near the Concave Wall Surface in the Returned Flow Type Cyclone Dust Collector

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Journal of Thermal Science 2010年第6期19卷 553-560页

作者： Akira ogawa T 110-0011. Minowa 2-14-7 Taitou-Ku Tokyo Japan

There are many types of cyclone dust collectors for separating the fine solid and dust particles from gases in the various industries and also in the home used purposes. For estimating the power loss and the collection efficiency, one of the most important factors is the maximum tangential velocity V0m in the vortex core region in the cyclone body. In order to determine V0~ by the simple method, it is useful to apply the mechanical balance of the angular momentum fluxes under the assumption of ogawa combined vortex model which is composed of the quasi-forced vortex in the vortex core region and also the quasi-free vortex surrounded the vortex core region and also under the assumption of the introduction of equivalent length Heq corresponding to the cone spaces of the cyclone body and the dust bunker. On the other hand, the mean rotational velocity Voi near the concave wall surface is also estimated by the mechanical balance of angular momentum fluxes with the moment of viscous friction force. For confirming the general applications of the obtained equations, the returned flow types cyclones changed the throat diameter D3 are designed. The material of the cyclone is the transparent acrylic resin. Therefore the inner surface of the cyclone body can be regarded as smooth surface. The comparisons of the measured velocities V~ and Voi by a cylindrical Pitot tube are shown in good agreement with those of the proposed equations. The above stated results are described in detail.

关键词： Cyclone Dust Collector Maximum Tangential Velocity Mean Rotational Velocity Angular Momentum Flux Equivalent Length Surface Frictional Force ogawa Combined Vortex Model Reynolds Number.

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Grain boundary functions as a spin valve

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National Science Review 2020年第7期7卷 1148-1149页

作者： yuichi Ikuhara Institute of Engineering Innovation The University of Tokyo Nanostructure Research Laboratory Japan Fine Ceramics Center

In practical applications, most metals and ceramic materials are used in polycrystalline form, composed of numbers of tiny single crystals called grains. The atomic arrangements at the interfaces between these grains, namely the grain boundaries(GBs), are very different from those inside the bulk part. The GB atomic structures are rather complicated and disordered, dependent on the orientations

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Visible light responsive photocatalysts developed by substitution with metal cations aiming at artificial photosynthesis

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Frontiers in Energy 2021年第3期15卷 568-576页

作者： yuichi YAMAGUCHI Akihiko KUDO Department of Applied Chemistry Faculty of ScienceTokyo University of ScienceTokyo 162-8601Japan

To solve resource,energy,and environmental issues,development of sustainable clean energy system is strongly *** recent years,hydrogen has been paid much attention to as a clean *** hydrogen production by water splitting using a photocatalyst as artificial photosynthesis is a promising method to solve these *** utilization of visible light comprised of solar light is essential for practical *** strategies,i.e.,doping,control of valence band,and formation of solid solution are often utilized as the useful methods to develop visible light responsive *** minireview introduces the recent work on visible-light-driven photocatalysts developed by substitution with metal cations of those strategies.

关键词： visible light responsive photocatalyst water splitting artificial photosynthesis:metal ion substitution

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