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ON THE ASYMPTOTIC DYNAMICS OF THE VLASOV-YUKAWA-BOLTZMANN SYSTEM NEAR VACUUM

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Acta Mathematica Scientia 2015年第4期35卷 887-905页

作者： Sun-ho choi Seung-Yeal HA Department of Mathematical Sciences KAIST Department of Mathematical Sciences and Research Institute of Mathematics Seoul National University

In this pape,~ we study uniform L1-stability and asymptotic completeness of the Vlasov-Yukawa-Boltzmann （V-Y-B） system. For a sufficiently small rand smooth initial data, we show that classical solutions exist globally and satisfy dispersion estimates, uniform L1-stability with respect to initial data and scattering type estimate. We show that the short range nature of interactions due to the Yukawa potential enables us to construct robust Lyapunov type functional to derive scattering states. In the zero mass limit of force carrier particles, we also show that the classical solutions to the V-Y-B system converge to that of the Vlasov-Poisson-Boltzmann （V-P-B） system in any finite time interval

关键词： asymptotic completeness collision operator the Vlasov-Yukawa-Boltzmannsystem uniform L1-stability

Enhanced Li^＋ storage properties of few-layered MoS2-C composite microspheres embedded with Si nanopowder

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Nano Research 2015年第8期8卷 2492-2502页

作者： Seung ho choi Yun Chan Kang Department of Materials Science and Engineering Korea University Anam-Dong Seongbuk-Gu Seoul 136-713 Republic of Korea

A few-layered MoS2-C composite material is studied as a supporting material for silicon nanopowder. Microspheres of the few-layered MoS2-C composite embedded with 30 wt.% Si nanopowder are prepared by one-pot spray pyrolysis. The Si nanopowder particles with high capacity are completely surrounded by the few-layered MoS2-C composite matrix. The discharge capacities of the MoS2-C composite microspheres with and without 30 wt.% Si nanopowder after 100 cycles are 1,020 and 718 mAh·g^-1 at a current density of 1,000 mA·g^-1 respectively. The spherical morphology of the MoS2-C composite microspheres embedded with Si nanopowder is preserved even after 100 cycles because of their high structural stability during cycling. The MoS2-C composite layer prevents the formation of unstable solid-electrolyte interface （SEI） layers on the Si nanopowder. Furthermore, as the MoS2-C composite matrix exhibits high capacity and excellent cycling performance, these characteristics are also reflected in the MoS2-C composite microspheres embedded with 30 wt.% Si nanopowder.

关键词： molybdenum sulfide silicon anode material lithium batteries spray pyrolysis

Development of vehicle-recognition method on water surfaces using LiDAR data:SPD^(2)(spherically stratified point projection with diameter and distance)

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Defence Technology（防务技术） 2024年第6期36卷 95-104页

作者： Eon-ho Lee Hyeon Jun Jeon Jinwoo choi Hyun-Taek choi Sejin Lee The Department of Mechanical Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea Ocean System Engineering Research Division Korea Research Institute of Ships and Ocean Engineering(KRISO)Daejeon 34103Republic of Korea The Division of Mechanical&Automotive Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea

Swarm robot systems are an important application of autonomous unmanned surface vehicles on water *** monitoring natural environments and conducting security activities within a certain range using a surface vehicle,the swarm robot system is more efficient than the operation of a single object as the former can reduce cost and save *** is necessary to detect adjacent surface obstacles robustly to operate a cluster of unmanned surface *** this purpose,a LiDAR(light detection and ranging)sensor is used as it can simultaneously obtain 3D information for all directions,relatively robustly and accurately,irrespective of the surrounding environmental *** the GPS(global-positioning-system)error range exists,obtaining measurements of the surface-vessel position can still ensure stability during platoon *** this study,a three-layer convolutional neural network is applied to classify types of surface *** aim of this approach is to redefine the sparse 3D point cloud data as 2D image data with a connotative meaning and subsequently utilize this transformed data for object classification ***,we have proposed a descriptor that converts the 3D point cloud data into 2D image *** use this descriptor effectively,it is necessary to perform a clustering operation that separates the point clouds for each *** developed voxel-based clustering for the point cloud ***,using the descriptor,3D point cloud data can be converted into a 2D feature image,and the converted 2D image is provided as an input value to the *** intend to verify the validity of the proposed 3D point cloud feature descriptor by using experimental data in the ***,we explore the feasibility of real-time object classification within this framework.

关键词： Object classification Clustering 3D point cloud data LiDAR(light detection and ranging) Surface vehicle

Ultrasound-guided intra-articular corticosteroid injection in a patient with manubriosternal joint involvement of ankylosing spondylitis:A case report

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World Journal of Clinical Cases 2023年第9期11卷 2043-2050页

作者： Min-Hee choi In-Young Yoon Won-joong Kim Department of Anesthesiology and Pain Medicine Ewha Womans University Mokdong HospitalSeoul 07985South Korea

BACKGROUND Manubriosternal joint(MSJ)disease is a rare cause of anterior chest pain but can be a major sign of systemic arthritic *** patients with ankylosing spondylitis(AS),a type of systemic arthritis,chest pain can be due to MSJ involvement and can be improved by ultrasound-guided corticosteroid injection into the *** SUMMARY A 64-year-old man visited our pain clinic complaining of anterior chest *** were no abnormal findings on lateral sternum X-ray,but arthritic changes in the MSJ were observed on single-photon emission computed tomography-computed *** performed additional laboratory tests,and he was finally diagnosed with *** pain relief,we performed ultrasound-guided intra-articular(IA)corticosteroid injections into the *** the injections,his pain nearly *** For patients complaining of anterior chest pain,AS should be considered,and single-photon emission computed tomography-computed tomography can be helpful in *** addition,ultrasound-guided IA corticosteroid injections may be effective for pain relief.

关键词： Ankylosing spondylitis Anterior chest pain Manubriosternal joint Single-photon emission computed tomography-computed tomography Case report

Subsurface scattering using splat-based diffusion in point-based rendering

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Science China(Information Sciences) 2010年第5期53卷 911-919页

作者： KIM Hyeon-joong BICKEL Bernd GROSS Markus choi Soo-Mi Department of Computer Engineering Sejong University Computer Graphics Lab ETH Zurich

Point-based graphics has gained much attention as an alternative to polygon-based approaches because of its simplicity and flexibility. however, current point-based techniques do not provide a sufficient rendering quality for translucent materials such as human skin. In this paper, we propose a point-based framework with subsurface scattering of light, which is important to create the soft and semi-translucent appearance of human skin. To accurately simulate subsurface scattering in multilayered materials, we present splat-based diffusion to apply a linear combination of several Gaussian basis functions to each splat in object space. Compared to existing point-based approaches, our method offers a significantly improved visual quality in rendering human faces and provides a similar visual quality to polygon-based rendering using the texture space diffusion technique. We demonstrate the effectiveness of our approach in rendering scanned faces realistically.

关键词： subsurface scattering point-based rendering skin rendering diffusion profile sum of Gaussian

Characteristics of Atmospheric Circulation Associated with Cold Surge Occurrences in East Asia:A Case Study During 2005/06 Winter

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Advances in Atmospheric Sciences 2008年第5期25卷 791-804页

作者： Tae-Won PARK Jee-hoon JEONG Chang-hoi ho Seong-joong KIM School of Earth and Environmental Sciences Seoul National University Seoul Korea Department of Earth Sciences University of Gothenburg Gothenburg Sweden Korea Polar Research Institute Incheon Korea

The characteristics of the upper-level circulation and thermodynamical properties for the period when two distinct cold surges broke out over East Asia during the 2005/06 winter are investigated. From early December 2005 to early January 2006, exceptionally cold weather lasted for approximately one month due to two successive cold surges that took place on 2 December 2005 and 2 January 2006, respectively. This study reveals that both involve the upper-tropospheric circulation, which induces the amplification and expansion of the surface Siberian high toward East Asia, but arose from different causes： the former is caused by the upper-level blocking originated from the North Pacific and the latter is caused by the upper-level wave train across the Eurasian Continent. In particular, it is suggested that the lower-tropospheric anomalous wind caused by upper-level circulation anomalies and a steep meridional temperature gradient amplified by phase-locked annual cycle combined to induce very strong cold advection in East Asia, which resulted in exceptionally cold weather that lasted for several weeks. The present results emphasize that the characteristics of the upper-tropospheric circulation can be considered as important precursors to cold surge occurrences in East Asia.

关键词： cold surge Siberian high East Asia East Asian winter monsoon upper-tropospheric circulation

Interplay between Plants and Microbial Communities:Insights from holobionts and Environmental Interactions

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Phyton-International Journal of Experimental Botany 2024年第10期93卷 2519-2534页

作者： Sejin choi ho-Seok Lee Department of Biology College of SciencesKyung Hee UniversitySeoul02447Republic of Korea Center for Genome Engineering Institute for Basic ScienceDaejeon34126Republic of Korea

Plants interact with a complex network of microorganisms,forming a dynamic holobiont that is crucial for their health,growth,and *** interconnected system is deeply influenced by environmental factors,which modulate the relationships within the plant *** environmental drivers such as light,temperature,and moisture can alter the balance of these interactions,impacting plant immunity,resilience,and overall *** traditional disease triangle model,which emphasizes plant-pathogen-environment interactions,is enhanced by incorporating the role of the microbiome,revealing how microbial communities contribute to disease *** review highlights the importance of shifting focus from studying plants in isolation to embracing an integrated approach that accounts for the intricate interactions between plants,microbes,and their surrounding *** these interactions is pivotal as we explore new approaches,including advanced sequencing technologies and microbiome engineering,to optimize plant-microbe relationships for improved crop *** insights are vital for developing sustainable agricultural practices to address the impacts of climate change and other environmental challenges.

关键词： holobiont disease triangle plant-associated microbiome temperature moisture circadian clock

Possibility of Solid Hydrometeor Growth Zone Identification Using Radar Spectrum Width

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Advances in Atmospheric Sciences 2023年第2期40卷 317-332页

作者： Sung-ho SUH Eun-ho choi hong-Il KIM Woonseon JUNG Flight Safety Technology Division NARO Space CenterKorea Aerospace Research Institute(KARI)508 Haban-roBongrae-myeonGoheung-gunJeollanam-do 59571Republic of Korea Research Applications Department National Institute of Meteorological Sciences33Seohobuk-roSeoqwipo-siJeju-do 63568Republic of Korea

In this study,the correlation between simulated and measured radar velocity spectrum width(σ_(v))is *** results show that the dendrites growth zones(DGZs)and needles growth zones(NGZs)mostly contain dendrites(DN)and needles(NE),***σ_(v) zones(1.11.2 m s^(-1),a differential reflectivity(ZDR)higher than 0 dB,and a cross-correlation coefficient(ρhv)less than *** contrast,prolate particles with relatively uniform shapes were observed in the NGZ withσ_(v)how that the DN exhibited a largerσ_(v) compared to the NE,and this observedσ_(v) was strongly dependent on the wind fluctuations(v’)due to turbulence or wind *** contrast,the NE exhibited a significantly smallσ_(v)~0.55 m s^(-1),which converges irrespective of v’.In addition,a strong correlation between the measuredσ_(v) values at five radar elevation angles(θ=6.2°,9.1°,13.1°,19°,and 80°)and those simulated in this study confirmed the significance of the analysis results.

关键词： spectrum width weather radar aerodynamic properties dendritic growth zone hydrometeor classifications

Chest wall metastasis from unknown primary site of hepatocellular carcinoma

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World Journal of Gastroenterology 2006年第13期12卷 2139-2142页

作者： Yil Sik Hyun ho Soon choi joong ho Bae Dae Won Jun Hang Lak Lee Oh Young Lee Byung Chul Yoon Min ho Lee Dong hoo Lee Choon Shuk Kee Jung ho Kang Moon Hyang Park Department of Internal Medicine Hanyang University College of Medicine SeoulKorea Department of Thoracic Surgery Hanyang University College of Medicine SeoulKorea Department of Pathology Hanyang University College of Medicine SeoulKorea

Previous reports of a solitary metastatic hepatocellular carcinoma have been rare. Because this tumor has a different treatment modality and prognosis, an accurate differential diagnosis is essential. Here we report a rare case of a solitary chest wall metastasis from unknown primary site of hepatocellular carcinoma. It involves a 51-year-old man who was admitted to our hospital because of a palpable left upper chest wall mass. The mass was resected and pathologic examination confirmed a diagnosis of metastatic hepatocellular carcinoma. Despite our investigation, no evidence was found that indicated the primary origin of the hepatocellular carcinoma. Four months later, the patient was admitted again because of spinal cord compression at the third and fourth thoracic vertebrae. Emergent decompressive laminectomy was performed and microscopic features revealed the same pathology as the initial chest wall mass resected 4 months earlier. After one year, a follow-up abdominal computed tomography （CT） still revealed no evidence of primary hepatocellular carcinoma.

关键词： Chest wall Hepatocellular carcinoma Metastasis