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Energy & Environmental Materials 2023年第2期6卷 397-407页

作者： Jingqiang Wang Duy Thanh Tran Kai Chang Sampath Prabhakaran Do Hwan kim Nam Hoon kim joong Hee Lee Department of Nano Convergence Engineering Jeonbuk National UniversityJeonjuJeonbuk 54896Korea Division of Science Education Graduate School of Department of Energy Storage/Conversion EngineeringJeonbuk National UniversityJeonjuJeonbuk 54896Korea Carbon Composite Research Center Department of Polymer-Nano Science and TechnologyJeonbuk National UniversityJeonjuJeonbuk 54896Korea

A heterostructured electrocatalyst of small NiSe_(2) nanoparticles confined NiMoN nanorods(NiSe_(2)-NPs/NiMoN-NRs)is prepared to accelerate both the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in a same alkaline *** synergistic effects caused by the combination of merits derived from NiSe_(2) and NiMoN phases trigger an optimum electronic structure with high density of state at near Fermi level and enhance adsorption free energy,thereby resulting in excellent catalytic activities and strengthened working *** catalyst requires a low overpotential of 58 mV for HER and 241 mV for OER to reach 10 mA cm^(−2) in 1.0 M KOH electrolyte.A twoelectrode electrolyzer based on the developed catalyst shows outstanding cell voltage of 1.51 and 1.46 V to reach 10 mA cm^(−2) in 1.0 M and 30 wt%KOH solution at 25℃ for overall water splitting,*** addition,the solardriven water splitting process delivers a high solar-to-H_(2) conversion efficiency of∼18.4%,impressively unveiling that the developed bifunctional catalyst is highly potential for overall water splitting to produce green hydrogen fuel.

关键词： Bifunctional electrocatalyst Novel NiSe_(2)/NiMoN heterostructures Solardriven water splitting Synergistic effects

Employment of encapsulated Si with mesoporous TiO_2 layer as anode material for lithium secondary batteries

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中国有色金属学会会刊：英文版 2009年第4期19卷 1023-1026页

作者： Sang-Eun PARK Bo-Eun kim Sang-Wha LEE joong-Kee LEE Advanced Energy Materials Processing Laboratory Korea Institute of Science and Technology Department of Chemical & Bio Engineering Kyungwon University

Silicon composite of nano-capsule type is newly applied as an active anode material for lithium ion ***2-encapsulated silicon powders were synthesized by a sol-gel reaction with titanium *** nanoparticles were successfully embedded into porous titanium oxide capsules that played as a buffer layer against drastic volume changes of silicon during the charge-discharge cycling,consequently leading to the retardation of the capacity fading of intrinsic silicon *** electrochemical and structural properties of silicon nanocomposites with different surface areas of encapsulating TiO2 layer were characterized by X-ray diffraction(XRD),nitrogen gas adsorption analysis by the Brunauer-Emmett-Teller(BET) equation,transmission electron microscopy(TEM),and galvanostatic charge-discharge experiments.

关键词：二氧化钛硅材料锂二次电池负极材料封装纳米复合材料透射电子显微镜就业

Epidural blood patch for spontaneous intracranial hypotension with subdural hematoma: A case report and review of literature

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World Journal of Clinical Cases 2022年第1期10卷 388-396页

作者： Se Hee Choi Youn Young Lee Won-joong kim Anesthesiology and Pain Medicine Ewha Womans University Mokdong HospitalSeoul 07985South Korea Anesthesiology and Pain Medicine School of MedicineEwha Womans UniversitySeoul 07985South Korea

BACKGROUND Cerebrospinal fluid(CSF)leakage at C1/2 in spontaneous intracranial hypotension(SIH)is *** hematoma(SDH),a serious complication of SIH,may lead to neurological *** report presents a case of SDH after spontaneous C1/2 CSF leakage,which was treated with a targeted epidural blood patch(EBP).CASE SUMMARY A 60-year-old man with no history of trauma was admitted to our hospital with orthostatic headache,nausea,and *** computed tomography imaging revealed bilateral,subacute to chronic *** magnetic resonance imaging(MRI)findings were SDH with dural enhancement in the bilateral cerebral convexity and posterior fossa and mild sagging,suggesting *** the patient underwent burr hole trephination,the patient’s orthostatic headache was *** myelography led to a suspicion of CSF leakage at C1/***,we performed a targeted cervical EBP using an epidural catheter under fluoroscopic *** 5 d after EBP,a follow-up MR myelography revealed a decrease in the interval size of the CSF *** his symptoms improved,the patient still complained of headaches;therefore,we repeated the targeted cervical EBP 6 d after the initial ***,his headache had almost disappeared on the 8th day after the repeated *** Targeted EBP is an effective treatment for SDH in patients with SIH due to CSF leakage at C1/2.

关键词： Cerebrospinal fluid Chronic subdural hematoma Epidural blood patch Myelography Spontaneous intracranial hypotension Case report

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Local pixel patterns

Computational Visual Media 2015年第2期1卷 157-170页

作者： Fangjun Huang Xiaochao Qu Hyoung joong kim Jiwu Huang School of Information Science and Technology Sun Yat-sen University Graduate School of Information Security Korea University College of Information Engineering Shenzhen University

In this paper, a new class of image texture operators is proposed. We firstly determine that the number of gray levels in each B × B subblock is a fundamental property of the local image texture. Thus, an occurrence histogram for each B × B sub-block can be utilized to describe the texture of the image. Moreover, using a new multi-bit plane strategy, i.e., representing the image texture with the occurrence histogram of the first one or more significant bit-planes of the input image, more powerful operators for describing the image texture can be obtained. The proposed approach is invariant to gray scale variations since the operators are, by definition,invariant under any monotonic transformation of the gray scale, and robust to rotation. They can also be used as supplementary operators to local binary patterns(LBP) to improve their capability to resist illuminance variation, surface transformations, etc.

关键词： texture multi-bit gray scale rotation

Periodic Tail Motion Linked to Wing Motion Affects the Longitudinal Stability of Ornithopter Flight

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Journal of Bionic Engineering 2012年第1期9卷 18-28页

作者： Jun-seong Lee joong-kwan kim Jae-hung Han Charles P. Ellington Department of Aerospace Engineering KAIST Daejeon 305701 South Korea Department of Zoology University of Cambridge Downing Street Cambridge CB2 3EJ UK

During slow level flight of a pigeon, a caudal muscle involved in tail movement, the levator caudae pars vertebralis, is activated at a particular phase with the pectoralis wing muscle. Inspired by mechanisms for the control of stability in flying animals, especially the role of the tail in avian flight, we investigated how periodic tail motion linked to motion of the wings affects the longitudinal stability of ornithopter flight. This was achieved by using an integrative ornithopter flight simulator that included aeroelastic behaviour of the flexible wings and tail. Trim flight trajectories of the simulated omithopter model were calculated by time integration of the nonlinear equations of a flexible multi-body dynamics coupled with a semi-empirical flapping-wing and tail aerodynamic models. The unique trim flight characteristics of ornithopter, Limit-Cycle Oscillation, were found under the sets of wingbeat frequency and tail elevation angle, and the appropriate phase angle of tail motion was determined by parameter studies minimizing the amplitude of the oscillations. The numerical simulation results show that tail actuation synchronized with wing motion suppresses the oscillation of body pitch angle over a wide range of wingbeat frequencies.

关键词： omithopter flapping flight periodic tail motion longitudinal flight stability aeroelasticity

EFFECT OF FABRICATION ON HIGH CYCLE FATIGUE PROPERTIES OF COPPER THIN FILMS

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Acta Mechanica Solida Sinica 2008年第4期21卷 318-326页

作者： Jun-Hyub Park joong-Hyok An Yun-Jae kim Hyeon-Chang Choi Department of Mechatronics Engineering College of EngineeringTongmyong University535Yongdang-DongNam-GuBusan608-711Korea Department of Mechanical Engineering College of EngineeringKorea UniversityAnam-dong Seongbuk-GuSeoul136-701Korea

The influence of fabrication on the tensile and fatigue behavior of copper films manufactured by 3 kinds of fabrication methods was investigated. The tensile and high cycle fatigue tests were performed using the test machine developed by authors. Young＇s moduli （72, 71 and 69 GPa, respectively） are lower than the literature values （108-145 GPa）, while the yield strengths were as high as 358, 350 and 346 MPa, respectively and the ultimate strengths as 462, 456 and 446 MPa, respectively. There is not much difference in the tensile properties of the 3 kinds of films. There is little difference in the fatigue properties of the 3 kinds of films but one of them has shorter fatigue life than others in high cycle region and longer fatigue life than others in low cycle region.

关键词： mechanical properties thin film copper high cycle fatigue test

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

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

Mechanical properties of high-strength concrete subjected to high temperature by stressed test

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中国有色金属学会会刊：英文版 2009年第B9期19卷 128-133页

作者： Gyu-Yong kim Young-sun kim Tae-Gyu LEE Division of Architecture Engineering Chun gnam National University

Recently, the effects of high temperature on compressive strength and elastic modulus of high strength concrete were experimentally investigated. The present study is aimed to study the effect of elevated temperatures ranging from 20 ℃ to 700 ℃ on the material mechanical properties of high-strength concrete of 40, 60 and 80 MPa grade. During the strength test, the specimens are subjected to a 25% of ultimate compressive strength at room temperature and sustained during heating, and when the target temperature is reached, the specimens are loaded to failure. The tests were conducted at various temperatures (20-700 ℃) for concretes made with W/B ratios of 46%, 32% and 25%, respectively. The results show that the relative values of compressive strength and elastic modulus decrease with increasing compressive strength grade of specimen.

关键词：高强混凝土高温作用力学性能测试抗压强度温度升高弹性模量强度试验