나사산 외관결함 검사용 환형 광학계 설계 및 해석

임영은(Yeong Eun Lim),이지원(Jiwon Lee),박근(Keun Park),나승우(Seung Woo Ra) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.5

3차원 프린팅으로 제작된 다공성 박판 구조물의 굽힘강성 고찰

임영은(Yeong-Eun Lim),박근(Keun Park) 대한기계학회 2017 大韓機械學會論文集A Vol.41 No.6

최근 3차원 프린팅 기술이 기존의 시작품 제작을 넘어서 직접 제조기술로서의 잠재력을 보이면서 많은 관심을 받고 있다. 3차원 프린팅은 기존의 제조공정으로는 불가능했던 복잡한 형상의 제작이 가능한 장점이 있으며, 이러한 장점으로 인해 경량화 구조물이나 부품이 일체화된 제품의 제조에도 사용되고 있다. 본 연구에서는 이러한 특성을 활용하여 제품의 경량화와 통기성 향상을 위한 다공성 박판 구조를 설계하였고, 유한요소해석을 통해 구조물의 굽힘강성을 비교하였다. 또한 다공성 구조물의 강성 저하를 보완하기 위한 보강설계를 수행하였고, 유한요소해석을 통해 보강구조물의 설계에 따른 굽힘강성 변화를 고찰하였으며 반응표면분석을 통해 설계변수의 최적화를 수행하였다 In recent years, 3D printing has received increasing attention due to its potential for direct fabrication beyond the traditional rapid prototyping. 3D printing has the advantage of being able to manufacture complicated shapes that were thought impossible to produce by traditional manufacturing processes. This advantage has driven applications of 3D printing to direct manufacturing of functional parts, such as lightweight structures and component integration. In this study, a porous shell structure is designed for the purpose of weight reduction and ventilation. Finite element (FE) analyses are performed to compare the effective stiffness of the porous structure with the conventional solid structure. Structural reinforcements are also considered in order to make up the stiffness reduction due to the porosity, and the relevant FE analyses are performed to investigate the effect of the reinforcement design on the bending stiffness. The optimized reinforced structure is then proposed through response surface analysis.

유한요소망을 이용한 다공성 박판 구조물의 자동설계

임영은(Yeong Eun Lim),박근(Keun Park) 대한기계학회 2018 大韓機械學會論文集A Vol.42 No.3

최근 3차원 프린팅은 기존의 시작품을 신속하게 제조하는 목적에서 기능성 제품을 직접 제조하는 방향으로 영역을 넓히고 있다. 3차원 프린팅은 형상의 제약 없이 복잡한 형상을 제작할 수 있는 특징이 있어 기존 제조공정상의 제한으로 인해 불가능했던 새로운 설계가 가능하다는 장점이 있다. 본 연구에서는 3차원 프린팅 적용을 목적으로 경량화 및 통기성 향상 등에 장점이 있는 다공성 박판 구조물의 자동설계 기법을 개발하였으며, 이를 위해 유한요소망에 기반한 다공성 구조 자동설계 알고리즘을 수치적으로 개발하였다. 개발된 알고리즘을 적용하여 요소망 크기와 구멍 크기에 따른 다공성 구조물 형상의 변화를 고찰하였으며, 요소망 크기 변화에 따라 구멍의 크기를 자동으로 조절할 수 있는 알고리즘을 구현하여 구멍간의 간섭 없이 표면밀도를 60% 이하로 낮출 수 있었다. In recent years, the applications of 3D printing have been extended from conventional rapid prototyping to direct fabrication of functional parts. The advantage of 3D printing, in its design flexibility and complexity, has driven modern design methods that can overcome traditional manufacturing constraints, and it has been applied to designs of lightweight structures or functional products. In this study, an automatic design of porous shell structures was developed for weight reduction and better ventilation of 3D printed parts. A numerical algorithm was developed to generate porous shell structures based on finite element mesh. The effects of mesh size and hole diameter were investigated in terms of the quality of the porous structures, and an algorithm to determine hole diameter was proposed to generate holes adaptively according to the target geometry and the relevant mesh density. As a result, surface density could be reduced lower than 60% without hole interference.

3차원 프린팅으로 제작된 다공성 경량 구조물의 변형 특성 연구

임영은(Yeong-Eun Lim),박근(Keun Park) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

In recent years, 3D printing has received increasing attention due to releases of low-cost personal printers. 3D printing has an advantage to manufacture complicated shapes, which has been impossible by traditional manufacturing process. This advantage has driven applications of 3D printing to fabrication of functional parts such as lightweight structure. In this study, a porous shell structure was designed for the purpose of weight reduction. Finite element (FE) analyses were performed to compare the effective stiffness of the porous structure with the conventional solid structure. Effect of structural reinforcement was also discussed in order to make up the stiffness reduction due to the porosity. FE analyses were performed to investigate the effect of the reinforcement design on the bending stiffness of the porous shells. As a results, we could obtain higher bending stiffness in comparison with the conventional shell structure.

나사산 전면검사 비전시스템의 영상 균일도 향상을 위한 조명 광학계 설계 및 해석

이창훈(Chang Hun Lee),임영은(Yeong Eun Lim),박근(Keun Park),나승우(Seung Woo Ra) Korean Society for Precision Engineering 2014 한국정밀공학회지 Vol.31 No.3

Precision screws have a wide range of industrial applications such as electrical and automotive products. To produce screw threads with high precision, not only high precision manufacturing technology but also reliable measurement technology is required. Machine vision systems have been used in the automatic inspection of screw threads based on backlight illumination, which cannot detect defects on the thread surface. Recently, an omnidirectional inspection system for screw threads was developed to obtain 360o images of screws, based on front light illumination. In this study, the illumination design for the omnidirectional inspection system was modified by adding a light shield to improve the image uniformity. Optical simulation for various shield designs was performed to analyze image uniformity of the obtained images. The simulation results were analyzed statistically using response surface method, from which optical performance of the omnidirectional inspection system could be optimized in terms of image quality and uniformity.

복강경 수술로 치료한 좌측 십이지장주위탈장

김병섭(Byung Seup Kim),임영아(Yong-Ah Lim),장경미(Kyung Mi Jang),김인규(In-Gyu Kim),전장용(Jang Yeong Jeon) 대한외과학회 2009 Annals of Surgical Treatment and Research(ASRT) Vol.77 No.5

Internal abdominal hernia is an unusual cause of intestinal obstruction. Paraduodenal hernia is relatively rare congenital malformations resulting from incomplete rotation of the midgut with entrapment of the small intestine beneath the developing colon. We report a case of paraduodenal hernia treated by laparoscopic approach. The patient was a 45-year-old man presenting with severe abdominal pain for 5 hours. Left paraduodenal hernia with jejunum hernia containing jejunal loops showed in abdominal CT. At operation, herniation of the small intestine into a retroperitoneal space through a defect on the left mesocolon was noted. After the herniated bowel was fully reduced, the hernia orifice was closed intra-corporeally in the manner of interrupted sutures with absorbable suture materials. The patient was discharged home without any serious complications on postoperative day 9. Conclusively, we think laparoscopic surgery in left paraduodenal hernia is feasible.

탄소저감 BAT 및 미생물을 이용한 음식물쓰레기 부하 저감시스템 개발

김장영(Kim Jang Yeong),양희성(Yang Hee Sung),임영은(Lim Yeong Eun),정원식(Chung Won-Sik) 한국유체기계학회 2022 한국유체기계학회 학술대회 논문집 Vol.2022 No.6

Development of Annular Optics for the Inspection of Surface Defects on Screw Threads Using Ray Tracing Simulation

이지원(Jiwon Lee),임영은(Yeong Eun Lim),박근(Keun Park),나승우(Seung Woo Ra) Korean Society for Precision Engineering 2016 한국정밀공학회지 Vol.33 No.6

This study aims to develop a vision inspection system for screw threads. To inspect external defects in screw threads, the vision inspection system was developed using front light illumination from which bright images can be obtained. The front light system, however, requires multiple side images for inspection of the entire thread surface, which can be performed by omnidirectional optics. In this study, an omnidirectional optical system was designed to obtain annular images of screw threads using an image sensor and two reflection mirrors; one large concave mirror and one small convex mirror. Optical simulations using backward and forward ray tracing were performed to determine the dimensional parameters of the proposed optical system, so that an annular image of the screw threads could be obtained with high quality and resolution. Microscale surface defects on the screw threads could be successfully detected using the developed annular inspection system.

후종골 점액낭염의 수술적 치료

김병직(Byung Jik Kim),임영(Yeong Lim),유문집(Moon Jip Yoo),이정한(Jeong Han Lee) 대한정형외과학회 1991 대한정형외과학회지 Vol.26 No.2

근 이동술 및 피부 이식을 이용한 하퇴부 연부조직 결손의 치료

김병직,고한석,김용욱,임영,이정한 인제대학교 1991 仁濟醫學 Vol.12 No.4

개방성 골절로 인한 연부 조직 결손 및 그 후유증으로 생긴 속발성 골수염 환자들에서 근 이동술 및 피부 이식을 동시에 시행하여 그 치유 기간의 단축 및 만족할 만한 결과를 얻었기에 문헌 고찰과 함께 보고하는 바이다. The incidence of open comminuted fractures are increasing because of frequent high energy injuries. The tibia is Particularly, vulnerable to open fracture and results in secondary osteomyelitis because of poor soft tissues. The management of soft tissue defect with bone exposure is extremely difficult. Recently, the muscle transposition technique has gained an accepted place in treating wide soft tissue defect with bone exposure because this technique is generally simple, safe and reliable. Eighteen patients who had open fractures or osteomyelitis of tibia wore treated with gastrocnemius and soleus muscle transposition at department of orthopaedic surgery. Seoul Paik Hospital from March 1987 to February 1990. The results were as follows : 1.Male predominate in 83.3%. 2.The main cause of lesion were open fracture in 88.9%. 3.The commonest muscle used for muscle transposition is medial head of gastrocnemius muscle, ie 83.3% of cases. 4.Mean duration from injury to operation is 30 months. 5.Skin graft was done immediately in 88.9%. 6.All cases were healed within 2 to 3 weeks after muscle transposition. We think this is the good procedure for the treatment of open fracture of the low leg.