EXPERIMENT AND CFD ANALYSIS OF THE PERFORMANCE A FLOATING WAVE ENERGY CONVERTER WITH A CROSS-FLOW TURBINE

Sangyoon Kim(김상윤),Byungha Kim(김병하),Youngho Lee(이영호) 한국신재생에너지학회 2015 한국신재생에너지학회 학술대회논문집 Vol.2015 No.6

Pre-immigration Screening for Tuberculosis in South Korea: A Comparison of Smear- and Culture-Based Protocols

( Sangyoon Lee ),( Ji Young Ryu ),( Dae-hwan Kim ) 대한결핵 및 호흡기학회 2019 Tuberculosis and Respiratory Diseases Vol.82 No.2

Background: Tuberculosis (TB) is the most important disease screened for upon patient history review during preimmigration medical examinations as performed in South Korea in prospective immigrants to certain Western countries. In 2007, the U.S. Centers for Disease Control and Prevention (CDC) changed the TB screening protocol from a smearbased test to the complete Culture and Directly Observed Therapy Tuberculosis Technical Instructions (CDOT TB TI) for reducing the incidence of TB in foreign-born immigrants. Methods: This study evaluated the effect of the revised (as compared with the old) protocol in South Korea. Results: Of the 40,558 visa applicants, 365 exhibited chest radiographic results suggestive of active or inactive TB, and 351 underwent sputum tests (acid-fast bacilli smear and Mycobacterium tuberculosis culture). To this end, using the CDOT TB TI, 36 subjects (88.8 per 105 of the population) were found to have TB, compared with only seven using the older U.S. CDC technical instruction (TI) (p<0.001). In addition, there were six drug-resistant cases which were identified (16.7 per 105 of the population), two of whom had multidrug-resistance (5.6 per 105 of the population). Conclusion: The culture-based 2007 TI identified a great deal of TB cases current to the individuals tested, as compared to older U.S. CDC TI.

Changes in Intraocular Pressure and Anterior Chamber Parameters Following Cataract Surgery, Vitrectomy, and Combined Surgery

Sangyoon Kim,Su Hwan Park,Seung Min Lee 대한안과학회 2024 Korean Journal of Ophthalmology Vol.38 No.1

Purpose: The aim of this study is to investigate changes in intraocular pressure (IOP) and anterior-segment parameters before and after cataract surgery, vitrectomy, and combined surgery. Methods: The records of patients who had undergone cataract surgery (cataract group), vitrectomy (vitrectomy group), or combined cataract surgery and vitrectomy (combined group) at our hospital were retrospectively examined. The vitrectomy group consisted of pseudophakic eyes. IOP and anterior-segment measurements, including anterior chamber depth (ACD), angle opening distance (AOD), trabecular-iris angle (TIA), and trabecular-iris space area (TISA), were measured using sweptsource anterior-segment optical coherence tomography before and 6 months after surgery in 41, 15, and 40 eyes, respectively. Results: In the cataract and combined groups, there was a decrease in IOP (cataract group: from 15.8 to 13.4 mmHg, p < 0.001; combined group: from 15.8 to 14.2 mmHg, p = 0.002) and an increase in the central corneal thickness after surgery (p < 0.001). The ACD increased in all groups, with a smaller increase in the vitrectomy group (p < 0.03). Postoperative AOD, TIA, and TISA were significantly increased in the cataract and combined groups (p < 0.02). Higher preoperative IOP and larger IOP reduction after surgery were correlated with smaller preoperative AOD, TISA, and TIA in cataract and combined groups (p < 0.034). A small preoperative ACD was related to smaller preoperative AOD, TISA, TIA (r > 0.649, p < 0.001), and postoperative IOP reduction in the cataract and combined groups (r = 0.377, p = 0.018 and r = 0.559, p = 0.001, respectively). Conclusions: Compared to the vitrectomy group, the cataract and combined groups showed reduced postoperative IOP and increased AOD, TISA, and TIA. In these two groups, patients with shallower preoperative ACDs showed greater changes in IOP after surgery. Changes in IOP after surgery are thought to be related to changes in the anterior segment caused by the removal of the crystalline lens.

Investigation on the inductive and resistive fault current limiting HTS power cable

Sangyoon Lee,Jongho Choi,Dongmin Kim,Yonghyun Kwon,Seokho Kim,Kideok Sim,Jeonwook Cho 한국초전도저온학회 (구 한국초전도저온공학회) 2014 한국초전도저온공학회논문지 Vol.16 No.2

Characteristics of Hemicellulase and Pectinase depending on Whey Protein Isolates Coating for Developing Elderly-Friendly Foods

SangYoon Lee,Honggyun Kim,Dong Hyeon Park,Jung Gyu Lee,Jingjing Bai,Hee Jeong Choi,Mi-Jung Choi 한국식품영양과학회 2017 한국식품영양과학회 학술대회발표집 Vol.2016 No.10

성별 격차가 경제구조 고도화 및 경제성장에 미치는 영향에 관한 연구

Sangyoon Kim,Jonggook Seo 한국재난정보학회 2017 한국재난정보학회 논문집 Vol.13 No.4

본 연구는 세계경제포럼에서 매년 발간하는 『The Global Gender Gap Report』의 전 세계 145개 국가를 대상으로 젠더 갭의 요인을 살펴보고 소득성장과 경제구조 고도화와의 관 계를 회귀분석을 통해 실증적으로 분석하였다. 분석 결과 젠더 갭의 요인 중 성비는 소득성 장의 지표인 GNI 성장률과 경제구조 고도화의 지표인 ICT 개발지수에 정(+)의 관계를 보였 고, 여성문맹률은 소득성장에만 유의미한 부(-)의 관계를 보였다. 여성국회의원비율은 소득 성장에만 유의미한 정(+)의 관계를 보였고, 여성노동참여율은 경제구조 고도화에만 유의미 한 정(+)의 관계를 보였다. 이 분석 결과를 통해 여러 국가들은 다가올 4차 산업혁명 시대에 여성노동에 대해 고민하며 대응하기 위한 제도 및 정책을 바탕으로 한 전략수립의 과제를 수립할 필요가 있다. Based on 『The Global Gender Gap Report』by World Economic Forum, this study identified factors of gender gap and analyzed a relationship between income growth and economic structural improvement with 145 countries. Consequently, sex ratio has a positive relationship with GNI growth rate and ICT development index. Female illiteracy has a negative relationship with only GNI growth rate, and female seat of parliament has a positive relationship with only with only GNI growth rate. Female labor participation rate has a positive relationship with inly ICT development index. These results confirmed the importance of future female labor force. With these results, many countries will need to reconsider discrimination against women and establish strategy based on an institution and a policy to prepare the 4th industrial revolution.

Analyzing the Interdependent Role of Network Centrality, Motivation and Ability in Knowledge Sharing

Sangyoon Jung(정상윤),Sangkyu Rho(노상규) 한국전자거래학회 2019 한국전자거래학회지 Vol.24 No.4

지식기반사회의 21세기에서 경쟁하는 기업들에게 조직구성원간의 지식공유는 기업의 핵심역량과 밀접한 연관을 갖는 핵심화두다. 특히 조직 내 네트워크의 위치 요인이 지식공유에 미치는 영향에 관해서는 학문적으로 논란이 계속되어 왔다. 이는 네트워크 중심성이 높을수록 정보에 대한 접근성이 높아지고 지식공유의 기회는 확대되는 반면에 약한 유대감으로 인해 실제 지식공유가 이루어지지 않는다는 논란이다. 본 연구에서는 지식 공유에 있어 세 가지 요소 - 네트워크 중심성, 자율적 동기, 그리고 지식공유능력 - 간의 상호작용이 지식공유에 미치는 영향을 보고자 한다. 그리고 더 나아가, 지식공유능력을 다양하고 깊이 있는 사전지식, SNS 활용능력, 그리고 자기효능감의 세 가지 측면으로 심도 있게 연구하였다. 그 결과, 부분적으로 네트워크 중심성과 자율적동기, 지식공유능력 간의 상호작용이 통계적으로 유의함을 밝혔다. 즉, 네트워크 중심성이 낮고, 높은 자율적동기, 그리고 사전지식이 많을 때 가장 높은 수준의 지식공유를 볼 수 있었다. 이를 통해, 동기와 능력이 강하면 네트워크의 주변적 위치라는 불리한 환경에서도 지식공유가 일어난다는 것을 알 수 있었다. 따라서 본 연구는 지식공유를 둘러싼 기존의 학문적 논쟁에 새로운 대안을 제시했다는 의의를 가진다. In the context of knowledge sharing, network position has been a controversial subject. A central position in the network provides access to non-redundant knowledge, leading to more opportunities of knowledge sharing. On the other hand, as “bridging” relationships, its characteristics as a “weak tie” suggest innate lack of trust and reciprocity which is considered an impediment to share knowledge. This paper attempts to enlighten the underlying dynamic by examining the interaction between network centrality, motivation and ability in knowledge sharing. Furthermore, this paper examines the concept of knowledge sharing ability in depth by operationalizing the construct into three aspects: extensive and diverse knowledge, social media utilization ability and self-efficacy. The results show a partially supported three-way interaction, where the highest level of knowledge provision is reported when the employee has low network centrality, high autonomous motivation and high knowledge sharing ability, i.e. extensive and diverse prior knowledge. Though all models indicate strong associations between network centrality and knowledge sharing, this suggests an even greater power of motivation and ability that gives the strength to overcome unfavorable environments of peripheral position. Therefore, this paper offers an alternative explanation to the existing debate whether network centrality positively or negatively influences knowledge sharing.

Piezoelectrically Actuated Self-Contained Quadruped Robot

Sangyoon Lee(이상윤),Thanhtam Ho(호탐탄) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

This paper presents the development of a mesoscale quadruped mobile robot that employs two pieces of piezocomposite actuators for the bounding locomotion. The overall design of the robot is inspired by legged insects, and in particular the leg structure of insects or animals is reflected on the robot in a simplified form, such that each leg of the robot has only one degree of freedom. The lack of degree of freedom is compensated for by a slope of the robot frame relative to the horizontal plane. For the implementation of self-contained mobile robot, a small power supply circuit is designed and fabricated. Experiments showed that the robot can locomote with the circuit on board, which can be a significant step toward the goal of building an autonomous legged robot actuated by piezocomposite actuators.

The Interactive Role of Network Centrality, Motivation and Ability in Knowledge Sharing

Sangyoon Jung,Sangkyu Rho 한국경영정보학회 2016 한국경영정보학회 학술대회논문집 Vol.2016 No.6

Hydraulic Model Test of a Floating Wave Energy Converter with a Cross-flow Turbine

Sangyoon Kim,Byungha Kim,Joji Wata,Young-Ho Lee 한국유체기계학회 2016 International journal of fluid machinery and syste Vol.9 No.3

Almost 70% of the earth is covered by the ocean. Extracting the power available in the ocean using a wave energy converter has been seen to be eco-friendly and renewable. This study focuses on developing a method for analyzing a wave energy device that uses a cross-flow turbine. The motion of the ocean wave causes an internal bi-directional flow of water and the cross-flow turbine is able to rotate in one direction. This device is considered of double-hull structure, and because of this structure, sea water does not come into contact with theturbine. Due to this, the problem of befouling on the turbine is avoided. This study shows specific relationship for wave length and several motions.