Investigation on Delamination Characteristics of 2-Ply Clad Metals and Adhesive Joints for Aluminum/Stainless Steel via the Peel Test

Jun‑Hyung Sim,Yungeun Ha,Min‑Kyun Kim,Min‑Joong Kim,Young‑Rae Cho 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

Bonding properties are important for metallic multilayer composites (MMCs) comprising different materials or materialswith different mechanical properties. In this study, we fabricated 2-ply Al/stainless steel (STS) clad metals and Al/adhesive(adh)/STS joints. To manufacture samples with various mechanical properties, T6 heat treatment was performed on cladmetals, and adhesive joints of several thicknesses were prepared. For each sample, the bonding strength was characterizedvia a T-peel test and the results were analyzed using the peeling angle. For 2-ply Al/STS clad metals, the T6 heat treatmentresulted in opposite trends in the mechanical properties. The bonding strength of 2-ply Al/STS clad metals was affectedby the peeling angle, i.e., a small peeling angle provided a small bonding strength at the interface. However, for the 2-plyAl/adh/STS joints, the bonding strength of adhesives on metals depended on each adherend of the stress state. As the differencein mechanical properties between the two adherends increased, the difference in each peeling angle of Al and STSalso increased. The peeling angle of adherends reached a limiting value when the sample contacted the clamping jig head;therefore, a new term, apparent bonding strength (ABS), is necessary to differentiate this new strength from the bondingstrength obtained under non-contact conditions. We believe that the concept of peeling angle and ABS proposed herein willplay a crucial role in describing the delamination behavior and bonding strength of MMCs via the peel test.

강릉수력발전소 발전수 방류 전후의 남대천 수질과 미생물 분포

심혜숙,김규중,김형섭,최창근,전방욱 江陵大學校東海岸地域硏究所 1993 東海岸硏究 Vol.4 No.1

강릉수력발전소의 발전수 방류가 강릉 남대천의 수질 및 미생물 분포에 미치는 영향을 조사하였다. 정점 3 상류지역의 발전수 방류는 수질에 상당한 영향을 끼쳐 정점 3 및 정점 4의 수질은 악화되고 정점 5, 정점 6 및 정점 7의 수질은 개선되었다. 미생물 분포도 이와 유사하여 정점 3 및 정점 4의 세포수는 상당히 증가한 반면 정점 5, 정점 6 및 정점 7에서는 대체적으로 감소하였다. 이 결과로 미루어보아 강릉수력발전소의 발전수는 희석효과에 의해 수질 및 미생물 분포를 변화시키는 것으로 사료된다. The effects of water discharged from Kangnung hydropower plant on the water quality and some bacterial population of Namdaecheon Stream, Kangnung were investigated. The water discharged above station 3 affected the water quality significantly; the water quality of station 3 and station 4 took a turn for the worse, however those of station 5, station 6 and station 7 changed for the better. It was also true with the bacterial population; The number of cells of bacteria increased in station 3 and 4, but the number significantly decreased in station 5, station 6, and station 7. The data suggested the idea that the water discharged from Kangnung hydropower plant changed the water quality and some bacterial population by dilution effect.

웹 기반을 통한 동시설계 구현에 관한 연구

김준안,이종춘,심재형 慶南專門大學 2001 論文集 Vol.29 No.1

인공신경망을 이용한 고장 심각도에 따른 무인기용 유성감속기의 고장진단 연구

박형준(Hyung Jun Park),심진우(Jinwoo Sim),장재원(Jaewon Jang),장경환(Kyung-Hwan Jang),설진운(Jin-Woon Seol),권준용(Jun-Yong Kwon),최주호(Joo-Ho Choi) 한국신뢰성학회 2021 신뢰성응용연구 Vol.21 No.4

Purpose: Gear teeth in the rotary geared actuator of the unmanned aerial vehicle, experience crack propagation because of its harsh operating conditions. To prevent the failure of catastrophic events, this study proposes a diagnostic approach for various gear crack levels based on the built-in and add-on sensor signal. Methods: A downsized planetary gearbox test rig was prepared, in which the motor position, current, and vibration signals were acquired for the normal and 4 different crack-induced states. Signals were filtered around the region of resonance frequencies by spectral kurtosis and the features for the health state were extracted. Then, feature selection was conducted based on the correlation with fault levels. Finally, the Artificial Neural Network (ANN) model was constructed to identify different fault sizes of the cracks, and K-fold validation was adopted to optimize the parameters of the ANN model. Results: Among the various signals, the vibration from the add-on sensor and a position from the built-in sensor exhibited high performance compared to the current signal. The features after band-pass filtering yielded a high correlation with fault severity. Conclusion: The proposed method successfully diagnosed different fault severities of gear cracks in the planetary gearbox by using both the built-in and add-on signals.

드론 사고 사례와 기술 동향에 따른 안티드론 대응 방안

심준형(Jun-Hyung Sim),황의천(Eu-Cheon Hwang),손창근(Chang-Gun Son),류연승(Yeon-Seung Ryu) 한국산학기술학회 2023 한국산학기술학회논문지 Vol.24 No.2

기존에 군사용 목적으로 개발된 드론은 기술 발전의 영향으로 관련 산업이 성장하고 드론 시장 역시 확대되고 있다. 이에 따라 드론 위험요인 역시 증가하고, 실제 드론으로 인한 다양한 사고들이 발생하고 있는 실정이다. 드론 위험 요인에 대한 대응 체계로서 등장한 안티드론은 탐지, 식별, 무력화의 과정을 통해 불법드론에 대응하고 있다. 실제로 많은 국가들이 드론 관련 사고 발생을 계기로 안티드론 시스템을 구축하고 있으며, 앞으로 드론 관련 기술 발전에 따라 드론의 활용도가 점진적으로 확대될 것으로 예상되는 만큼 우리나라에서도 드론 위험요인에 대한 실효성 있는 대응 체계의 구축이 요구된다. 또한 현재 활발하게 연구가 진행되고 있는 드론 무력화 기술의 실질적인 적용을 위해서는 드론 위험요인에 대한 정확한 파악이 전제되어야 하며, 특히 탐지와 식별 관련 기술 개발의 활성화가 요구된다. 향후 위험요인의 파악 및 고도화된 탐지 식별 기술을 토대로 보호 대상자나 시설물의 환경적 특성을 고려한 안티드론 대응 체계 방향이 설정되어야 할 것이다. Drones developed for military purposes are growing related industries and expanding the drone market due to technological advances. Accordingly, drone risk factors are also increasing, and various accidents due to actual drones are occurring. Anti-drone, which has emerged as a response system to drone risk factors, is responding to illegal drones through detection, identification, and neutralization. Indeed, many countries are building anti-drone systems in the wake of drone-related accidents. The use of drones is expected to expand gradually due to the development of drone-related technologies. Hence, Korea must establish an effective response system to drone risk factors. In addition, for the practical application of drone neutralization technology, which is currently being actively researched, accurate identification of drone risk factors must be premised. In particular, the development of detection and identification-related technologies is required. In the future, based on the identification of risk factors and advanced detection and identification technology, the direction of an anti-drone response system should be set, considering the environmental characteristics of persons subject to protection or facilities.

Caerulein과 총담췌장관 결찰에 의한 급성췌장염 모델의 특징

심상수,김현준,이윤혜,박진형,이승준,김창종 중앙대학교 약학연구소 2000 약학 논총 Vol.14 No.-

To investigate the difference in acute pancreatitis experimentally induced by common bile-pancreatic duct (CBPD) ligation and caerulein iv infusion, we measured amylase activity, pancreatic edema and phospholipase A_2 activity in pancreatic tissue and serum. In acute pancreatitis induced by CBPD ligation and caerulein infusion, tissue edema and tissue phospholipase A_2 activity significantly increased as compared with normal group. Also experimental acute pancreatitis significantly increased the levels of serum protein, serum amylase activity and serum phospholipase A_2 activity. In the comparison of two experimental models, the symptom of acute pancreatitis induced by CBPD ligation was more severe than that induced by caerulein infusion. These results indicate that the increase of phospholipase A_2 activity in pancreatic tissue and serum may be one of the parameters for the diagnosis of acute pancreatitis.

Effect of the Laser Beam Size on the Cure Properties of a Photopolymer in Stereolithography

Sim, Jae-Hyung,Lee, Eun-Dok,Kweon, Hyeog-Jun Korean Society for Precision Engineering 2007 International Journal of Precision Engineering and Vol.8 No.4

Stereolithography (SLA) is a technique using a laser beam to cure a photopolymer liquid resin with three-dimensional computer-aided design (CAD) data, The accuracy of the prototype, the build time, and the cured properties of the resins are controlled by the SLA process parameters such as the size of the laser beam, scan velocity, hatch spacing, and layer thickness, In particular, the size of the laser beam is the most important parameter in SLA, This study investigated the curing properties of photopolymers as a function of the laser beam size, The cure width and depth were measured either on a single cure line or at a single cure layer for various hatch spacings and laser beam sizes, The cure depth ranged from 0.23 to 0.34 mm and was directly proportional to the beam radius, whereas the cure width ranged from 0.42 to 1.07 mm and was inversely proportional to the beam radius, The resulting surface roughness ranged from 1.12 to $2.23{\mu}m$ for a ratio of hatch spacing to beam radius in the range 0.5-2.0 at a beam radius of 0.17 mm and a scan velocity of 125 mm/sec.

Case Reports : Castleman Disease Presenting with Jaundice: A Case with the Multicentric Hyaline Vascular Variant

Jun Bean Park,Jin Hyeok Hwang,Hae Ryoung Kim,Hyung Sim Choe,Yu Kyeong Kim,Hong Bin Kim,Soo Mee Bang 대한내과학회 2007 The Korean Journal of Internal Medicine Vol.22 No.2

Castleman disease (CD) is a rare lymphoproliferative disorder of unknown etiology with different clinical manifestations. A previous healthy 50 year-old man was hospitalized for right upper quadrant (RUQ) abdominal pain. He had jaundice and a 1 cm-sized lymph node in the right supraclavicular area. Pancreas and biliary computed tomography (CT) showed masses at the right renal hilum and peripancreatic areas. Positron emission tomography (PET) showed widespread systemic lymphadenopathy. Excisional biopsy of the right supraclavicular node revealed a hyaline vascular variant of CD. Corticosteroid therapy was started and the extent of disease decreased. We here report a case of multicentric CD, the hyaline vascular variant, presenting with jaundice, diagnosed by excisional biopsy and successfully treated with corticosteroids.

나일론 타올에 의한 반상 유전분증 1예

심형준,김승희,도기승,장민수,서기석,김상태 대한피부과학회 2004 대한피부과학회지 Vol.42 No.1

Amyloidosis is a disorder of protein metabolism characterized by the extracellular deposition of abnormal protein fibrils. We report a case of macular amyloidosis due to nylon towel on his back. A 61-year-old male presented with asymptomatic hyperpigmented macules on the scapulae for 6 years. He had a habit of scrubbing his back for many years with a rough nylon towel while taking a bath. The histologic examination revealed liquefaction degeneration and homogenous eosinophilic deposition in the papillary dermis. In Congo red, amyloid material stained positively and in anti-keratin antibody staining. He had neither clinical nor laboratory evidence of systemic amyloidosis. A diagnosis of friction amyloidosis was made on histological and immunohistopathological findings. (Korean J Dermatol 2004;42(1):119~121)

장폐쇄를 유발한 회장 자궁내막증식증 1예

김준호,박형석,진춘조,공수정,최의광,민미심,이경영,윤상애 大韓消化器病學會 1996 大韓消化器病學會誌 Vol.28 No.6