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Energy & Environmental Materials 2024年第1期7卷 147-152页

作者： Sun Kyung Hwang Ik jae park Se Won Seo jae hyun park So Jeong park Jin Young Kim Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Korea Department of Applied Physics Sookmyung Women's UniversitySeoul 04310Korea Research Institute of Advanced Materials and Systems Sookmyung Women's UniversitySeoul 04310Korea Research Institute of Advanced Materials(RIAM) Seoul National UniversitySeoul 08826Korea

In spite of the high potential economic feasibility of the tandem solar cells consisting of the halide perovskite and the kesterite Cu2ZnSn(S,Se)4(CZTSSe),they have rarely been demonstrated due to the difficulty in implementing solution-processed perovskite top cell on the rough surface of the bottom ***,we firstly demonstrate an efficient monolithic two-terminal perovskite/CZTSSe tandem solar cell by significantly reducing the surface roughness of the electrochemically deposited CZTSSe bottom *** surface roughness(R_(rms))of the CZTSSe thin film could be reduced from 424 to 86 nm by using the potentiostatic mode rather than using the conventional galvanostatic mode,which can be further reduced to 22 nm after the subsequent ion-milling *** perovskite top cell with a bandgap of 1.65 eV could be prepared using a solution process on the flattened CZTSSe bottom cell,resulting in the efficient perovskite/CZTSSe tandem solar *** the current matching between two subcells involving the thickness control of the perovskite layer,the best performing tandem device exhibited a high conversion efficiency of 17.5%without the hysteresis effect.

关键词： CZTSSe monolithic tandem solar cells perovskite solution process surface roughness control

Complications and management of forgotten long-term biliary stents

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World Journal of Gastroenterology 2017年第4期23卷 622-628页

作者： Se Hoon Sohn jae hyun park Kook hyun Kim Tae Nyeun Kim Division of Gastroenterology and Hepatology Department of Internal MedicineYeungnam University College of MedicineDaegu 42415South Korea

AIMTo evaluate complications and management outcomes of retained long-term plastic biliary *** plastic biliary stent placement was performed in 802 patients at Yeungnam University Hospital between January 2000 and December 2014. Follow-up loss with a subsequently forgotten stent for more than 12 mo occurred in 38 patients. We retrospectively examined the cause of biliary stent insertion, status of stents, complications associated with biliary stents and management outcomes of long-term plastic biliary stents. Continuous variables were analyzed using the t test. Observed frequencies in subsets of the study population were compared using Fisher’s exact test and χ2 tests. Statistical significance was defined as P < 0.05 (two-tailed).RESULTSMean age of patients was 73.7 ± 12 years and male-to-female ratio was 2.2:1. Indications of plastic biliary stent insertion were bile duct stones (63.2%, 24/38) and benign bile duct stricture (52.6%, 20/38). Mean duration of retained plastic stent was 22.6 ± 12.2 mo, and in 10 cases (26.3%), stents were retained for more than 24 mo. Common bile duct (CBD) stones or sludge were found in most cases (92.1%, 35/38). The most common complication was acute cholangitis (94.7%, 36/38). Stent removal by endoscopic approach was successfully performed in 92.1% (35/38) of the cases. In 3 cases, an additional plastic stent was inserted alongside the previous stent due to failure of the stent removal. Endoscopic removal of bile duct stones was successful in 73.7% (28/38) of the cases. When patients were divided into two groups by duration of stent placement (12 to 24 mo vs over 24 mo), there were no differences in the development of cholangitis, presence of biliary stones, and success rate of endoscopic removal of stones and biliary *** most common complication of retained long-term plastic biliary stents was acute cholangitis associated with CBD stones. Endos

关键词： Biliary stent Long-term complications Forgotten stents Acute cholangitis Biliary stone

Prediction of the indication criteria for endoscopic resection of early gastric cancer

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World Journal of Gastroenterology 2015年第39期21卷 11160-11167页

作者： jae hyun park Si hyung Lee Joon Mo park Chan Seo park Kyung Sik park Eun Soo Kim Kwang Bum Cho Department of Internal Medicine Yeungnam University College of Medicine Department of Internal Medicine Keimyung University College of Medicine

AIM: To find risk factors of lymph node metastasis(LNM) in early gastric cancer(EGC) and to find proper endoscopic therapy indication in ***: We retrospectively reviewed the 2270 patients who underwent curative operation for EGC from January 2001 to December 2008. EGC was defined as malignant lesions that do not invade beyond the submucosal layer of the stomach wall irrespective of presence of lymph node ***: Among 2270 enrolled patients, LNM was observed in 217(9%) patients. LNM in intramucosal(M) cancer and submucosal(SM) cancer was detectedin 3 8( 2. 8 %, 3 8 / 1 3 4 0) patients and 1 7 9(19%, 179/930) patients, respectively. In univariate analysis, the risk factors for LNM in EGC were size of tumor, Lauren classification, ulcer, lymphatic invasion, vascular invasion, and depth of invasion. However, in multivariate analysis, size of tumor, lymphatic invasion, vascular invasion, and depth of invasion were risk factors for LNM in EGC. Size of tumor, lymphatic invasion, vascular invasion, and depth of invasion were risk factors for LNM in cases of intramucosal cancer and submucosal cancer. In particular, there was no lymph node metastasis in cases of well differentiated early gastric cancer below 1 cm in size without ulcer regardless of lymphovascular ***: Tumor size, perilymphatic-vascular invasion, and depth of invasion were risk factors for LNM in EGC. There was no LNM in EGC below 1 cmregardless risk factors.

关键词： Early gastric cancer Lymph node metastasis Endosco

Effect of molybdenum on interfacial properties of titanium carbide reinforced Fe composite

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Journal of Materials Science & Technology 2022年第12期107卷 252-258页

作者： Seungchan Cho Junghwan Kim Ilguk Jo jae hyun park jaekwang Lee hyun-Uk Hong Bong Ho Lee Wook Ryol Hwang Dong-Woo Suh Sang-Kwan Lee Sang-Bok Lee Composites Research Division Korea Institute of Materials Science(KIMS)Changwon 51508South Korea Advanced Materials Engineering Dong-Eui UniversityBusan 47340South Korea Department of Aerospace and Software Engineering Gyeongsang National UniversityJinju 52828South Korea Department of Physics Pusan National UniversityBusan 46241South Korea Department of Materials Convergence and System Engineering Changwon National UniversityChangwon 51140South Korea Center for Core Research Facilities Daegu Gyeongbuk Institute of Science and TechnologyDaegu 42988South Korea School of Mechanical Engineering Gyeongsang National UniversityJinju 52828South Korea Graduate Institute of Ferrous Technology Pohang University of Science and TechnologyGyeongbuk 37673South Korea

This study shows that the mechanical strength of the composite of Fe matrix and titanium carbide(Ti C)ceramic particles is significantly enhanced with addition of molybdenum(Mo) atoms. Ti C reinforced Fe(Fe-0.2C-7Mn) composites with and without Mo were fabricated by a liquid pressing infiltration(LPI)process and the effect of Mo on interfacial properties of TiC–Fe composite was investigated using atomic probe tomography(APT) analysis, molecular dynamics(MD) simulations, first-principle density functional theory(DFT), and thermodynamic calculations. First, DFT calculations showed that total energies of the Mo-doped Ti C–Fe superlattices strongly depend on the position of Mo defects, and are minimized when the Mo atom is located at the TiC/Fe interface, supporting the probable formation of MoC-like interphase at the TiC/Fe interface region. Then, APT analysis confirmed the DFT predictions by finding that about6.5 wt.% Mo is incorporated in the Ti C–Fe(Mo) composite and that sub-micrometer thick(Ti,Mo)C interphase is indeed formed near the interface. The MD simulations show that Mo atoms migrate to the Mo-free TiC–Fe interface at elevated temperatures and the mechanical strength of the interface is considerably enhanced, which is in good agreement with experimental observations.

关键词： Metal matrix composites(MMCs) Titanium carbide Fe matrix composite Infiltration Molybdenum Interfacial property

A computational study of the chemokine receptor CXCR1 bound with interleukin-8

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Chinese Physics B 2018年第3期27卷 534-543页

作者： Yang Wang Cecylia Severin Lupala Ting Wang Xuanxuan Li Ji-Hye Yun jae-hyun park Zeyu Jin Weontae Lee Leihan Tan Haiguang Liu Complex Systems Division Beijing Computational Science Research Center Beijing 100193 China Genome Center University of California Davis 451 East Health Science Drive Davis CA 95616 USA Department of Engineering physics Tsinghua University Beijing 100086 China Department of Biochemistry College of Life Science ＆ Biotechnology Yonsei University Seou103722 South Korea Department of Physics and Institute of Computational and Theoretical Studies Hong Kong Baptist University Hong Kong China

CXCR1 is a G-protein coupled receptor, transducing signals from chemokines, in particular the interleukin-8 （1L8） molecules. This study combines homology modeling and molecular dynamics simulation methods to study the structure of CXCRI-IL8 complex. By using CXCR4-vMIP-II crystallography structure as the homologous template, CXCRI-IL8 complex structure was constructed, and then refined using all-atom molecular dynamics simulations. Through extensive simulations, CXCRI-IL8 binding poses were investigated in detail. Furthermore, the role of the N-terminal of CXCR1 receptor was studied by comparing four complex models differing in the N-terminal sequences. The results indicate that the receptor N-terminal affects the binding of IL8 significantly. With a shorter N-terminal domain, the binding of IL8 to CXCR1 becomes unstable. The homology modeling and simulations also reveal the key receptor-ligand residues involved in the electrostatic interactions known to be vital for complex formation.

关键词： CXCRI-IL8 complex homology modeling ligand binding molecular dynamics

Earthquake Fragility Assessment of the Underground Tunnel Using an Efficient SSI Analysis Approach

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Journal of Applied Mathematics and Physics 2014年第12期2卷 1073-1078页

作者： Thai Son Le Jungwon Huh jae-hyun park Department of Civil and Environmental Engineering Chonnam National University Yeosu Korea Department of Geotechnical Research Engineering Korea Institute of Civil Engineering and Building Technology Goyang Korea

This paper represents a simplified seismic fragility analysis approach of the underground tunnel structure in consideration of the soil-structure interaction (SSI) effect. SSI effect founds to be essential in the estimation of dynamic analysis of underground structures like tunnels and thus needs to be considered. The ground response acceleration method for buried structures (GRAMBS) known to be a very efficient quasi-static method that can consider SSI effect is used in the proposed approach to evaluate seismic structural responses without sacrificing much accuracy. Seismic fragility curves are then developed by applying the maximum likelihood estimates (MLE) to responses of a large set of artificial ground motion time histories generated for multiple different levels of earthquake intensity. It is also assumed in this paper that the seismic fragility curve can be represented by a two-parameter lognormal distribution function with median and log-standard deviation that need to be defined using MLE.

关键词： Soil-Structure Interaction Maximum Likelihood Fragility Curves Dynamic Analysis

Optimal Trajectory Planning of the Dual Arm Manipulator Using DAMM

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Journal of Measurement Science and Instrumentation 2011年第2期2卷 127-131页

作者： Chi-sung park jae-hyun park Jang-myung LEE Dept.of Electrical Engineering Pusan National UniversityBusan 609-735Korea

This paper presents an optimal trajectory planning method of the dual arm manipulator using Dual Arm Manipulability Measure （DAMM）. When the manipulator carries an object from a certain position to the destination, various trajectory candidates could be conskied. TO select the optimal trajectacy from the several candidates, energy, time, and the length of the tmjecttay could be utilized. In order to quantify the carrying effidency of dual-arms, DAMM has been defined and applied for the decision of the optimal path. DAMM is defined as the interaction of the manipulability ellipsoids of the dualarras, while the manipulability measure irdicates the relationship between the joint velocity and the Cartesian velocity for each ann. The cast function for achieving the optimal path is defined as the Summation of the distance to the goal and inverse of this DAMM, which aims to generate the efficient motion to the goal. It is confirmed that the optimal path planning keeps higher manipulability through the short distance path by using computer simulation. To show the effectiveness of this cooperative control algorithm experimentally, a 5-DOF dual-ann robot with distributed controllers for synchronization control has been developed and used for the experiments.

关键词： DAMM dual-arm optimal trajectory manipulability distributed controller

Thermal Radiation, Joule Heating, and Viscous Dissipation Effects on MHD Forced Convection Flow with Uniform Surface Temperature

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Open Journal of Fluid Dynamics 2014年第2期4卷 125-132页

作者： M. Y. Abdollahzadeh Jamalabadi jae hyun park Department of Aerospace and System Engineering Research Center for Aircraft Parts Technology Gyeongsang National University Jinju South Korea Maritime University of Chabahar Chabahar Iran

In this paper, we studied the effects of thermal radiation, Joule heating and viscous dissipation on forced convection flow in a magnetohydrodynamics (namely MHD) pump in rectangular channel with uniform surface temperature. Numerical results were obtained by solving the nonlinear governing momentum and energy equations with steady state fully developed assumptions by finite difference method. The Lorentz force in momentum and Joule heating, and viscous dissipation in energy equation with the Rossel and approximation are assumed to increase the knowledge of the details of the temperature and flow field in order to design a MHD pump. The purpose of this study is the parametric study of a Newtonian fluid in a MHD pump. The values of maximum velocity, fully developed Nusselt number for different values of magnetic density flux, Brinkman number, viscous heating and radiation number are obtained. However, the maximum temperature stays almost constant with magnetic field, as current increases, the velocity and the temperature increase too. Besides, the increase of thermal radiation number causes the increase in effective thermal conductivity and decrease in thermal boundary layer and the Nusselt number at wall.

关键词： Forced Convection Thermal Radiation Magnetohydrodynamic Pump Internal Heating Viscous Dissipation Roseland Model

A Study on Development of Balanced Scorecard for Management Evaluation Using Multiple Attribute Decision Making

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Journal of Software Engineering and Applications 2010年第3期3卷 268-272页

作者： Kwang Mo Yang Young Wook Cho Seung Hee Choi jae hyun park Kyoung Sik Kang Department of Industrial & Management Engineering Myongji University Yongin Korea Department of Industrial & Manufacturing Engineering Pennsylvania State University Pennsylvania USA. Department of Industrial Engineering Yuhan University Puchoen Korea Department of Qualification Trend Analysis Human Resource Development Service Seoul Korea Department of Technology & Systems Management Induk Institute of Technology Seoul Korea

Recently, most businesses have introduced a system for improving their responsibility to the customers in terms of job improvement. For example, small-quantity batch production increases cost but improve efficiency of management. Companies have been introduced the balanced scorecard to evaluate their management as part of improvement, while they suffer from many trials and errors. Many businesses still have difficulty in introducing balance scorecard concept in their process, but we suggest a method to successfully introduce the balance scorecard. This study aims to suggest a new performance measurement model reflecting relative importance of the key performance indicators for each factor. Our model is applied to several companies in real-world to validate the new model. Also, our study proposes a methodology for an adequate performance measurement using multiple attribute decision making.

关键词： Balanced Scorecard Multiple Attribute Decision Making Management Evaluation

Evaluation of factors affecting the success rate of orthodontic mini-implants by survival analysis

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World Journal of Stomatology 2013年第3期2卷 56-61页

作者： Un-Bong Baik Mohamed Bayome Kwang-Heung Han jae hyun park Min-Ho Jung Yoon-Ah Kook Smile with Orthodontic Clinic Seoul 142-100 South Korea Department of Orthodontics The Catholic University of Korea Seoul 137-701 South Korea Seoul H Dental Clinic Seoul 150-037 South Korea Postgraduate Orthodontic Program Arizona School of Dentistry and Oral Health A.T. Still University Mesa AZ Graduate School of Dentistry Kyung Hee University Seoul 130-701 South Korea Private practice and Department of Orthodontics School of Dentistry Seoul National University Seoul 151-742 South Korea Department of Orthodontics Seoul St. Mary’s Hospital The Catholic University of Korea Seoul 137-701 South Korea

AIM: To investigate the success rate of mini-implants and its characteristics and risk factors by survival analyses. METHODS: Three hundred and ninety-four miniimplants of the same type were placed by a single clinician. Age, gender, treatment duration, time of failure, side and jaw of implantation and the soft tissue at placement site were recorded. Odds ratio, survival curves, and Cox proportional hazard model were applied to evaluate the factors influencing the miniimplants' success rate. RESULTS: The cumulative success rate was 88.1%.The maxilla had a significantly higher success rate than that of the mandible(91.7% vs 83.7%, respectively, P = 0.019). Placement of mini-implants in the attached gingiva(AG) showed a higher success rate than that of the mucogingival junction(MGJ) and mucous membrane(MM)(AG, 94.3%; MGJ, 85.8%; MM, 79.4%; P < 0.001). Significant association was found between the jaw and the gingival tissue type(P < 0.001). There were no significant differences between maxilla and mandible when compared within each placement ***: The gingival tissue type had the most significant effect on the success rate of the mini-implant with higher success rate in the attached gingiva.

关键词： Mini-implant Success rate Survival analysis Gingival tissue Treatment planning