유한요소법을 이용한 필렛용접 이음부의 잔류응력분포

김현성,우상익,정경섭,Kim, Hyun Sung,Woo, Sang Ik,Jung, Kyoung Sup 한국강구조학회 2000 韓國鋼構造學會 論文集 Vol.12 No.2

본 연구는 유한요소법을 이용해서 시간이력 열전도해석과 열탄성해석을 통해 필렛용접 이음부에서의 잔류응력분포를 측정하였다. 필렛용접은 1패스 용접이며, 경계조건으로는 표면유속조건과 온도에 의존하는 재료의 특성치를 고려하여 잔류응력을 평가하였다. 여기서, 용접입열양을 변수로 하였다. 그리고, 열탄성해석에 의해 잔류응력 평가할 때 중요한 문제로 언급되고 있는 cut-off 온도 설정에 대해 조사하였다. 또한, 시험체에서 구멍뚫기 방법에 의해 잔류응력분포를 측정하여 유한요소법에 의한 잔류응력분포와 비교하였다. 그 결과, 용접부에서는 재료의 항복강도 수준에 해당하는 인장잔류응력이 측정되었으며, 유한요소해석에 의한 수치해석 결과는 구멍뚫기 방법에 의한 측정치 및 다른 연구자의 측정치와 비교적 일치하는 것으로 나타났다. 그리고, Cut-off 온도는 재료의 항복강도가 나타나는 온도로 설정하는 것이 효과적임을 알 수 있었다. A transient heat transfer analysis and thermo-elastic analysis have been performed for the residual stress distribution on the fillet weldment used by finite element method. Specimen is fabricated single-pass fillet welding. This computation was performed for conditions including surface heat flux and temperature dependent thermo-physical properties using by heat input as parameter. Also, cut-off temperature of residual stress estimation by thermo-elastic analysis is determined. The fillet weldment were measured to determined their residual stress distributions for using hole-drilling method. As result, it was found that large tensile residual stress is about material yield strength, and the numerical simulation results for finite element method similar to residual stresses by hole-drilling method and other exiting research. Also, cut-off temperature is effectively determined by temperature which calculated maximum thermal stress equal to material yield strength.

알루미늄 내성과 민감성 보리의 빠른 screening과 원형질막 H⁺-ATPase의 발현

김현성,오정민,안성주,Kim, Hyun-Sung,Oh, Jung-Min,Ahn, Sung-Ju 한국작물학회 2011 한국작물학회지 Vol.56 No.1

Here we report a simple screening system using hematoxylin staining (HS) of the root apex. It allowed rapid classification into different aluminum (Al) tolerance from 65 cultivars within one week. Using this system, we selected the most Al-tolerant (Jayae-2) and-sensitive (Pum-2) barley (Hordeum vulgare L.) The results show that the different responses in Al-induced growth inhibition, Al accumulation and expression of plasma membrane (PM) $H^+$-ATPase in root apices of selected two cultivars. It showed strongly Al-induced growth inhibition in a dosedependant manner only in Pum-2 but not in Jayae-2. Aluminum accumulation in root apices (10 mm) was significantly higher in Pum-2 only. The $H^+$-ATPase expression of PM vesicles by western blotting was decreased in Pum-2 but not in Jayae-2 treated with $20{\mu}M$ Al for 24 h. These finding indicate to screen from our system is rapid and reliable and to sustain the expression of PM $H^+$-ATPase at translational level is an important role in root growth as affected by Al.

성격이 미소에 끼치는 영향에 관한 연구

김현성,김일평,오상천,동진근,Kim, Hyun-Seong,Kim, Il-Pyung,Oh, Sang-Chun,Dong, Jin-Keun 대한치과보철학회 1996 대한치과보철학회지 Vol.34 No.4

There has been a lot of research into the essence of the smile, but so far just a few studies have been done on the relationship between personality and smile. On the assumption that smile aesthetics are closely related to individual physical condition and psychological state, this study investigated the correlation between personality factors and smile scores. The Personality Factor Questionnaire test was administered to 60 university students (male : 30, female : 30) who have no teeth missing, no experience of orthodontic or prosthodontic treatment and good dentition. Then, portraits were taken in a full smile. Esthetic smile scores were estimated by 10 appraisers who were dentists. These scores were analyzed statistically using the SAS program. The following results were obtained. 1. Personality factors of Warmth, Stableness, Surgency, Boldness, Untroubled-adequacy, Group-dependence, Relaxation, Extraversion, Low anxiety were positively correlated to the aesthetic level of smile. 2. For females, personality factors had greater influence on smile aesthetics, whereas male smile aesthetics were less influenced by personality factors.

자가 진피지방술을 이용한 집게조갑의 교정

김현성,김철한,강상규,탁민성,Kim, Hyun-Sung,Kim, Chul-Han,Kang, Sang-Gue,Tark, Min-Seong 대한성형외과학회 2010 Archives of Plastic Surgery Vol.37 No.3

Purpose: Pincer nail is a relatively rare deformity characterized by an increase in transverse curvature along the longitudinal axis of the nail. This curvature commonly increases from proximal to distal end of nail, leading to pinching, curling, and distortion of the underlying soft tissue and resulting frequently in severe pain. Numerous surgical procedures have been reported. Preserving the width of the nail in the correction of the pincer nail is very important for functional and aesthetic reasons. We report the results of the correction of the pincer nail using autogenous dermofat graft with a good result. Methods: From May 2006 to September 2008, dermofat graft was performed in 6 patients with pincer nail. Patients were four women and two men, and the average age was 51. The affected digits were the unilateral great toes in four patients and the unilateral thumbs in two patients. Average follow-up period was 13 months. Surgical procedure was removal of nail using an elevator to avoid damage to the nail bed. An incision was created in distal portion of hyponychium. Paronychium was dissected from distal phalanx by periosteal elevator through incision of hyponychium and tunnel was made. Then dermofat grafts harvested from inguinal area were inserted into the tunnel. Finally, a silicone sheet was inserted eponychial fold for prevention of synechia. Objective assessment was evaluated by use of the width index and height index. Results: All patients reported resolution of the pain and soft tissue pinching sensation that they had before the operation. There was good adherence between the nail plate and the underlying nail bed. The nails have regrown and were corrected in a normal and flattened appearance. The width index and height index were improved. Conclusion: The autogenous dermofat graft seems to provide an effective treatment of the pincer nail with preservation of the nail matrix.

Genetic Diversity of Hepatitis C Virus in Korea

김현성,최준호,이효석,Kim, Hyun-Sung,Choe, Joon-Ho,Lee, Hyo-Suk 대한미생물학회 1996 Journal of Bacteriology and Virology Vol.26 No.1

C형 간염바이러스 (HCV)는 각 개체간에 뉴클레오티드 서열상의 다양성을 나타내고, 이러한 유전적 다양성이 임상병리적 증상과 밀접한 연관이 있을 것으로 고려되어 왔다. 본 연구에서는 HCV E1과 NS5B 부위의 염기서열 분석을 통해 한국의 C형 간염바이러스의 분포와 다양성에 관해 분석하고, 발생계통도를 그려 HCV간의 진화적 거리를 확인하였다. 염기서열분석은 서울대학교 병원과 충남대학교 병원으로부터 얻은 56개의 HCV-양성 혈청을 대상으로 RT-PCR과 PCR 과정을 통해 얻은 유전자 산물을 클로닝하여 수행되었다. 56개의 혈청중 53개의 샘플에서 HCV RNA가 검출되었다. 이들 53개 샘플에 대한 분석 곁과, 유전형 1a, 1b, 2a, 2b, 7a가 각각 5.7, 45.3, 45.3, 1.9, 1.9%로 분포하고 있고, 1b형과 2a형이 한국에서의 주요한 HCV 유전형으로 밝혀졌다. 본 연구는 염기서열 분석을 통해 한국에서 1b형과 마찬가지로 2a형도 높은 빈도로 분포하고 있고, 비록 분포 빈도는 낮지만 1a 형과 7a 형도 존재하고 있음을 밝힌 최초의 보고이다.

600 nm급 폴리에스터 해도형 초극세사 편성물의 감량 및 염색 특성

김현성,신은숙,이정진,Kim, Hyun Sung,Shin, Eun Suk,Lee, Jung Jin 한국섬유공학회 2014 한국섬유공학회지 Vol.51 No.1

The weight reduction and dyeing properties of circular-knitted fabric manufactured from sea-island-type polyethylene terephthalate (PET) ultramicrofiber were investigated. The diameter of a single fiber was approximately 600 nm. The results of scanning electron microscopy (SEM) analysis, alkali dissolution ratio measurements, and cationic dye staining method revealed that the dissolution of the sea component from each ultramicrofiber was completed through alkali treatment with 1% NaOH aqueous solution for 30-40 min at $95^{\circ}C$. The color yield of the disperse dye on the fabric was observed to be dependent on the dyeing temperature. The color yield increased with an increase in the dyeing temperature up to $120^{\circ}C$, and then decreased at $130^{\circ}C$. The build-up property was generally good. The wash fastness was poor and the light fastness was very poor.

근전도유도하 윤상인두근 보톡스 주입 술의 유용성

김현성,정은재,노영수,박동식,Kim, Hyun-Sung,Chung, Eun-Jae,Rho, Young-Soo,Park, Dong-Sik 대한기관식도과학회 2013 大韓氣管食道科學會誌 Vol.19 No.1

Objective The objective was to evaluate changes in swallow safety and dietary status after the transcutaneous injection of botulinum toxin into the upper esophageal sphincter in a series of outpatients with dysphagia. Methods Patients who were at risk for aspiration and who had an unsuccessful trial of swallowing therapy were admitted to the study. All patients showed significant pooling of fluids in the pyriform sinus. All patients were treated in the office; none had previous esophageal dilatation. The upper border of the cricoid cartilage was identified using standard electromyogram procedures and botulinum toxin was injected. Outcomes were assessed using the penetration-aspiration scale, NIH swallowiwng safety score, patients' short-term and long-term subjective impressions of their ability to swallow, and change in dietary status. Results Ten patients underwent an instrumental evaluation of swallowing function. Of the 10 patients, 9 showed an overall improvement in their ability to take an oral diet safely. The penetration-aspiration scale, NIH swallowiwng safety score, patients' short-term and long-term subjective impressions of their ability to swallow, and change in dietary status were significantly improved after office-based botox injection. Conclusion Office-based EMG guided botox injection to the cricopharyngeus muscle is a simple, safe, and effective tool for dysphagia patients. Injection of Botox in the office should be considered when the dysphagia pattern is aspiration after swallow.

스마트카드와 지문을 이용한 강화된 ID기반의 인증 기법

전일수,김현성,Jeon Il-Soo,Kim Hyun-Sung 한국정보처리학회 2005 정보처리학회논문지 C : 정보통신,정보보안 Vol.12 No.7

최근에 KIM03[9]은 지문과 스마트카드를 이용한 ID기반의 인증 기법을 제안하였다. 하지만 Scott[10]은 KIM03의 인증 기법이 소극적 공격(Passive attack)에 취약함을 보였다. 본 논문에서는 KIM03의 인증 기법에 존재하는 문제점을 해결할 수 있는 강화된 ID기반의 인증 기법을 제안한다. 특히, 본 논문에서 제안한 기법은 기존의 ID 기반의 암호화 시스템이 공유하는 문제점인 ID 복구문제(Repairability)를 해결한다. 본 논문에서 제안한 ID 기반의 인증 프로토콜은 ID기반의 암호화 시스템의 장점을 유지하면서 이 방식의 문제점들을 효율적으로 해결한다. Recently, Kim et al. proposed ID-based authentication schemes using smartcards and fingerprints. However, Scott showed that they were vulnerable to the passive eavesdropping attack. Thereby, this paper proposes an enhanced ID-based authentication scheme to solve the problems in Kin et al. scheme. Especially, the proposed scheme solves the ID repairability problem commonly shared in the previous ID based Cryptosystems. The proposed ID-based authentication scheme supports the advantages in the previous ID-based authentication scheme and solves the problems in them effectively.

배열식 파력발전 시스템의 구조안전성 평가

김현성(Hyun-Sung Kim),김병완(Byoung Wan Kim),박지용(Ji Yong Park),신승호(Seungho Shin) 한국해양환경·에너지학회 2021 한국해양환경공학회 학술대회논문집 Vol.2021 No.5

기존 화석연료의 고갈 및 환경오염 문제에 대한 관심이 증가함에 따라 친환경 에너지에 대한 연구가 활발히 진행되고 있다. 이 중 해양환경 및 공간을 활용한 발전의 경우, 육상 발전에서 발생할 수 있는 여러 제약들을 해결할 수 있어, 이에 대한 연구들이 증가하고 있다. 특히, 파랑에너지의 경우 에너지원이 풍부하며, 넓은 공간을 활용할 수 있어 발전 단지를 통한 대용량 발전이 가능하다. 이에 따라 선박해양플랜트연구소에서는, 파랑에 의한 회전운동을 통해 발전하는 가동물체형 파력발전장치(로터)를 연속적으로 배치함으로, 대용량 발전이 가능한 1MW급 배열식 파력발전 시스템을 개발하였다. 개발된 배열식 파력발전 시스템은 부유식 플랫폼과 다수의 발전용 로터로 구성되며, 각각의 플랫폼과 로터는 트러스 구조물 및 힌지를 통해 연결된다. 본 연구에서는 파랑 중 배열식 파력발전 시스템의 구조안전성을 평가하고자 하였다. 고차경계요소법(Higher-Order Boundary Element Method, HOBEM)을 활용하여 플랫폼 및 로터에 작용하는 파랑하중을 산출하였다. 구조해석의 경우 유한요소법(Finite Element Method, FEM)을 적용하였으며, 플랫폼과 로터는 쉘요소로 모델링하였으며, 이들을 연결하는 트러스 구조물의 경우 보요소를 적용함으로써 해석을 수행하였다. 극한조건에서의 최대응력 및 피로조건에서의 피로하중 및 수명을 검토하여 배열식 파력발전 시스템의 설계조건 중 피로안전성을 평가하였다. As increasing the interest on depletion of existing energy source, fossil fuel, and environmental pollution, the studies on eco-friendly and renewable energies are actively progressing. The studies on energy generation using offshore environment and space are on the increase because the offshore generation could solve the limitations in inland generation. In case of wave energy, the source is abundant and the large capacity of energy generation is possible by creating the energy generation complex through the very large offshore space. Korea Research Institute of Ships and Ocean Engineering(KRISO) has developed 1MW class buoy-arrayed wave energy generation system that arranges the floating type wave energy converters. The wave energy converter generates electricity by wave-induced rotational motion. The developed buoy-arrayed wave energy converter consists of floating platforms, rotors, truss structure, and hinge connection. The truss structure have a role to connect platforms and rotors. In this work, the structural safety for buoy-arrayed wave energy converter under wave condition for evaluated. Wave loads on platforms and rotors are estimated by applying Higher-Order Boundary Element Method(HOBEM). Finite Element Method(FEM) is utilized for structural analysis, and platforms and rotors are modeled by shell elements and truss structure are done by beam elements. Structural safety of the wave energy converter under the design condition is evaluated by investigating the maximum stress in extreme condition and fatigue damage/life in wave probability distribution condition.

전자관인인증시스템을 활용한 전자적 민원서비스 혁신에 관한 연구

김현성(Hyun-Sung Kim) 한국지역정보화학회 2003 한국지역정보화학회지 Vol.6 No.2