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Portable Dynamic Positioning Control System on A Barge in Short-Crested Waves Using the Neural Network Algorithm

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China Ocean Engineering 2013年第4期27卷 469-480页

作者： FANG Ming-chung lee Zi-yi Department of Systems and Naval Mechatronic Engineering National Cheng Kung University

This paper develops a nonlinear mathematical model to simulate the dynamic motion behavior of the barge equipped with the portable outboard Dynamic Positioning （DP） system in short-crested waves. The self-tuning Proportional- Derivative （PD） controller based on the neural network algorithm is applied to control the thrusters for optimal adjustment of the barge position in waves. In addition to the wave, the current, the wind and the nonlinear drift force are also considered in the calculations. The time domain simulations for the six-degree-of-freedom motions of the barge with the DP system are solved by the 4th order Runge-Kutta method which can compromise the efficiency and the accuracy of the simulations. The technique of the portable alternative DP system developed here can serve as a practical tool to assist those ships without being equipped with the DP facility while the dynamic positioning missions are needed.

关键词： neural network PD controller dynamic positioning short-crested wave

Dynamic genetic features of eukaryotic plankton diversity in the Nakdong River estuary of Korea

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Chinese Journal of Oceanology and Limnology 2017年第4期35卷 844-857页

作者： lee Jee Eun chung Ik Kyo lee Sang-Rae Division of Earth Environmental System Oceanography Major Pusan National University Marine Research Institute Pusan National University

Estuaries are environments where freshwater and seawater mix and they display various salinity *** construction of river barrages and dams has rapidly changed these environments and has had a wide range of impacts on plankton *** understand the dynamics of such communities,researchers need accurate and rapid techniques for detecting plankton *** evaluated the diversity of eukaryotic plankton over a salinity gradient by applying a metagenomics tool at the Nakdong River estuary in *** samples were collected on three dates during summer and autumn of 2011 at the Eulsukdo Bridge at the mouth of that *** the 18 S rDNA allowed us to analyze 456 clones and 122 *** sequences revealed various taxonomic groups and cryptic genetic variations at the intra-and inter-specific *** analyzing the same station at each sampling date,we observed that the phylotypes presented a salinity-related pattern of diversity in *** variety of species within freshwater samples reflected the rapid environmental changes caused by freshwater *** phylotypes accounted for the highest proportion of overall diversity in the seawater *** diatoms and dinoflagellates were observed in the freshwater,brackish and seawater *** biological data for species composition demonstrate the transitional state between freshwater and ***,this metagenomics information can serve as a biological indicator for tracking changes in aquatic environments.

关键词： 18S rDNA clone library metagenome estuary salinity gradient

The effects of Y pre-alloying on the in-situ dispersoids of ODS Co Cr Fe Mn Ni high-entropy alloy

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Journal of Materials Science & Technology 2021年第26期85卷 62-75页

作者： SeungHyeok chung Bin lee Soo Yeol lee Changwoo Do Ho Jin Ryu Department of Nuclear and Quantum Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea Manufacturing Technology Office Korea Institute for Rare MetalKorea Institue of Industrial TechnologyGet-Pearl TowerGaetbeol-ro 12Yeonsu-guIncheon 21999Republic of Korea Department of Materials Science and Engineering Chungnam National UniversityDaejeon 34134Republic of Korea Neutron Scattering Division Oak Ridge National LaboratoryOak RidgeTN 37831USA

Oxide dispersion strengthened CoCrFeMnNi high-entropy alloys(ODS-HEAs)were prepared using two different powder preparation methods classified by yttrium addition strategy to investigate the effects of in-situ and ex-situ oxide dispersoid formation on the microstructure and mechanical *** micro structural analysis was carried out by X-ray diffraction(XRD),electron backscattered diffraction(EBSD),high-resolution transmission electron microscopy(HRTEM),atom probe tomography(APT),and small-angle neutron scattering(SANS).Cryo-milled powder analysis,grain structure evolution after spark plasma sintering,dispersoid characteristics,and matrix/dispersoid interface structure analysis of the insitu and ex-situ dispersoids within the high-entropy alloy(HEA)matrix were *** in-situ dispersoid formation was dominantly observed in the Y-alloyed ODS-HEA through the construction of a coherent interface relationship with complex chemical composition,leading to an increase in the Zener pinning forces on the grain boundary ***-HEA with in-situ oxide dispersoids enhanced the formation of ultrafine-grained structures with an average diameter of 330 nm at a sintering temperature of 1173 *** study shows that the Y pre-alloying method is efficient in achieving fine coherent dispersoids with an ultra fine-grained structure,resulting in an enhancement of the tensile strength of the CoCrFeMnNi HEA.

关键词： Oxide dispersion strengthened(ODS)alloy High-entropy alloy In-situ oxide dispersoid formation Microstructure Mechanical property

Effects of TiC on the microstructure refinement and mechanical property enhancement of additive manufactured Inconel 625/TiC metal matrix composites fabricated with novel core-shell composite powder

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Journal of Materials Science & Technology 2023年第33期164卷 13-26页

作者： Taegyu lee Wonjong Jeong SeungHyeok chung Ho Jin Ryu Department of Materials Science and Engineering Korea Advanced Institute of Science and TechnologyYu Seong-GuDae Hak-Ro 29134141 DaejeonRepublic of Korea Department of Nuclear and Quantum Engineering Korea Advanced Institute of Science and TechnologyYu Seong-GuDae Hak-Ro 29134141 DaejeonRepublic of Korea

The flexible product shape of additive manufacturing(AM)is attractive,but the process suffers from a lack of material property diversity due to a limited number of printable alloys and post-processing *** overcome this problem,the AM of metal matrix composites(MMCs)is a highly suitable solution because the properties of MMC can be tailored using various ***,extensive research has been conducted on the AM of MMCs;however,the major huddle for this process has been the difficulties in preparing feedstock powder and operating the AM *** study introduces an easily synthesizable core-shell composite powder,which was fabricated by a recently developed process called the SMART *** core-shell powder has a novel morphology,consisting of a metal core and composite shell,distinguishing it from the powders used in conventional AM *** 625/TiCp composites were fabricated using the core-shell composite powder,with various fractions of TiCp up to 10 vol.%.Compared to additive-manufactured Inconel 625,the additive-manufactured MMCs showed enhanced strength with significantly fewer *** results of this study may accelerate the application of MMC fabricated by AM,which offers superior properties and reliability compared to casting and powder metallurgy due to the higher degree of dislocation density and reinforcement dispersion.

关键词： Powder treatment Composite powder Metal matrix composite Additive manufacturing Nickel-based superalloy Directed energy deposition

Recent Advances in Cuticular Wax Biosynthesis and Its Regulation in Arabidopsis

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Molecular Plant 2013年第2期6卷 246-249页

作者： Saet Buyl lee Mi chung Suh Department of Bioenergy Science and Technology Chonnam National University Gwangju Korea

The aerial parts of land plants are covered with cuticu- lar waxes that limit non-stomatal water loss and gaseous exchanges, and protect plants from ultraviolet radiation and pathogen attacks. They are composed of very-long-chain fatty acids （VLCFAs; C20 to C34） in addition to their deriva-tives, aldehydes, alkanes, primary and secondary alcohols, and wax esters. Due to their physical properties, such as solid-ity at room temperature and a translucency ranging from transparent to opaque, plant waxes have been used as raw materials in the production of cosmetics, detergents, plas-tics, soaps, paints, drugs, lubricants, and high-value renew-able fuels. Many genes involved in cuticular wax biosynthesis and export have been characterized by forward and reverse genetic approaches as well as by stem epidermis transcrip-tome analysis. The regulatory mechanisms of cuticular wax biosynthesis have been reported at the transcriptional, post- transcriptional, and translational levels. Recent advances in cuticular wax biosynthesis and its regulation are reviewed in this paper.

关键词： ARABIDOPSIS PLANT cuticle PLANT products -- Synthesis TRANSCRIPTION ENZYMES

Deep Learning-Based Action Classification Using One-Shot Object Detection

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Computers, Materials & Continua 2023年第8期76卷 1343-1359页

作者： Hyun Yoo Seo-El lee Kyungyong chung Contents Convergence Software Research Institute Kyonggi UniversitySuwon-si16227Korea Department of Public Safety Bigdata Kyonggi UniversitySuwon-si16227Korea Division of Computer Science and Engineering Kyonggi UniversitySuwon-si16227Korea

Deep learning-based action classification technology has been applied to various fields,such as social safety,medical services,and *** an action on a practical level requires tracking multiple human bodies in an image in real-time and simultaneously classifying their *** are various related studies on the real-time classification of actions in an ***,existing deep learning-based action classification models have prolonged response speeds,so there is a limit to real-time *** addition,it has low accuracy of action of each object ifmultiple objects appear in the ***,it needs to be improved since it has a memory overhead in processing image *** learning-based action classification using one-shot object detection is proposed to overcome the limitations of multiframe-based analysis *** proposed method uses a one-shot object detection model and a multi-object tracking algorithm to detect and track multiple objects in the ***,a deep learning-based pattern classification model is used to classify the body action of the object in the image by reducing the data for each object to an action *** to the existing studies,the constructed model shows higher accuracy of 74.95%,and in terms of speed,it offered better performance than the current studies at 0.234 s per *** proposed model makes it possible to classify some actions only through action vector learning without additional image learning because of the vector learning feature of the posterior neural ***,it is expected to contribute significantly to commercializing realistic streaming data analysis technologies,such as CCTV.

关键词： Human action classification artificial intelligence deep neural network pattern analysis video analysis

Self-sustained oscillation for compressible cylindrical cavity flows

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Chinese Journal of Aeronautics 2017年第4期30卷 1294-1299页

作者： Kung-Ming chung Kuan-Huang lee Keh-Chin CHANG Aerospace Science and Technology Research Center National Cheng Kung University Tainan 711 China Department of Aeronautics and Astronautics National Cheng Kung University Tainan 701 China

The presence of a cavity changes the mean and fluctuating pressure distributions. Similarities are observed between a cylindrical cavity and a rectangular cavity for a compressible *** type of cavity flow field depends on the diameter-to-depth ratio and the length-to-depth *** feedback loop is responsible for the generation of discrete acoustic tones. In this study, the selfsustained oscillation for a compressible cylindrical cavity flow was investigated experimentally. For open-type cavities, the power spectra show that the strength of resonance depends on the diameterto-depth ratio（4.43–43.0） and the incoming boundary layer thickness-to-depth ratio（0.72–7.0）. The effective streamwise length is used as the characteristic length to estimate the Strouhal number. At higher modes, there is a large deviation from Rossiter＇s formula for rectangular cavities. The gradient-based searching method was used to evaluate the values of the empirical parameters. Less phase lag and a lower convection velocity are observed.

关键词： Cavity flow Compressible flow Convection velocity Open cavity Oscillation

100 W-class green hydrogen production from ammonia at a dual-layer electrode containing a Pt-Ir catalyst for an alkaline electrolytic process

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Journal of Energy Chemistry 2024年第6期93卷 352-360,I0009页

作者： Donghyun Yoon Sunki chung Minjun Choi Eunhyeok Yang Jaeyoung lee School of Earth Sciences and Environmental Engineering Gwangju Institute of Science and Technology(GIST)Gwangju 61005Republic of Korea International Future Research Center of Chemical Energy Storage and Conversion Processes GISTGwangju 61005Republic of Korea Ertl Center for Electrochemistry and Catalysis GISTGwangju 61005Republic of Korea TKG Huchems Co.Ltd 963Sangam-roYeosu-siJeollanam-do 59614Republic of Korea

Ammonia allows storage and transport of hydrogen over long distances and is an attractive potential hydrogen *** decomposition has recently been used for the conversion of ammonia to hydrogen and is regarded as a future technology for production of CO_(2)-free pure ***,a heterostructural Pt-Ir dual-layer electrode is developed and shown to achieve successful long-term operation in an ammonia electrolyzer with an anion exchange membrane(AEM).This electrolyzer consisted of eight membra ne electrode assemblies(MEAs)with a total geometric area of 200 cm~2 on the anode side,which resulted in a hydrogen production rate of 25 L h~(-1).We observed the degradation in MEA performance attributed to changes in the anode catalyst layer during hydrogen production via ammonia ***,we demonstrated the relationship between the ammonia oxidation reaction(AOR)and the oxygen evolution reaction(OER).

关键词： Ammonia oxidation Dual-layer catalyst Green hydrogen Electrolytic process Oxygen evolution reaction

Prostate only radiotherapy using external beam radiotherapy:A clinician’s perspective

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World Journal of Clinical Cases 2022年第29期10卷 10428-10434页

作者： Jeong Won lee Mi Joo chung Department of Radiation Oncology Daegu Catholic University School of MedicineDaegu 42472South Korea Department of Radiation Oncology Hanyang University Hanmaeum Changwon HospitalChangwon 51139South Korea

Prostate-only radiotherapy(PORT) is widely used as the definitive treatment for localized prostate *** cancer has an α/β ratio;therefore,radiotherapy(RT) with a large fraction size is biologically effective for tumor *** current external beam RT technique for PORT has been improved from threedimensional conformal RT to intensity-modulated,stereotactic body,and imageguided *** methods are associated with reduced radiation exposure to normal tissues,decreasing urinary and bowel *** trials have shown improved local control with dose escalation through the aforementioned methods,and the efficacy and safety of intensity-modulated and stereotactic body RTs have been ***,the management of RT in patients with prostate cancer has not been fully *** a clinician,there are several concerns regarding the RT volume and dose considering the patient’s age and ***,this review aimed to discuss the radiobiological basis and external beam technical advancements in PORT for localized prostate cancer from a clinician’s perspective.

关键词： Prostate cancer Radiotherapy Radiation dose Radiation technique Radiation volume