나사산이 있는 관이음의 효과적인 해석모델의 개발

임중연,이호용,고광일 東國大學校 1996 東國論叢 Vol.35 No.-

This paper is concerned with and efficient model for the structural analysis of threaded connections which is used to assemble the tubular connections such as pipes. Advanced mechanics has been used to develop the model which yields acceptably accurate solutions for stresses when compared to other methods such as experimental or finite element analysis procedures. Beam-on-elastic-foundation equations are used to compute stresses due to assembly of the connection while bolt-nut equation and Lame' equation are used for axial loads and pressures. Numerical results show that our model is computationally efficient and valid in terms of stress distribution for make-up. The current model can provide the quick and inexpensive analysis tools to the production engineer with reasonable accuracy.

수동변속기 트랜스미션케이스의 피로파괴 분석

임중연 동국대학교 산업기술연구원 1996 산업기술논문집 Vol.7 No.-

본 논문은 로드-로드 스펙트럼 분석기법을 적용하여 자동차 트랜스미션케이스의 피로파괴분석을 다룬 것이다. 수동변속기의 트랜스미션케이스는 다양한 주기적 하중을 받고 있으며 결과적으로 케이스표면에 가끔 균열이 발생되기도 한다. 본 연구에서는 지지방식이 엔지 3점지지 방식에서 트랜스미션 3점지지 방식으로 바뀌면서 발생하는 균열의 원인분석에 관한 것이다. 트랜스미션 3점지지 방식은 내구시험중 드레인플러그 부위에서 균열이 조기발생되었다. 이러한 원인을 정량적으로 분석하기 위하여 1 사이클 내구시험동안 각각의 지지방식에 대하여 누적손상량을 계산할 수 있는 실험 및 컴퓨터를 이용한 분석이 병행되었다. 결과적으로 트랜스미션 3점지지 방식이 엔진 3점지지 방식보다 트랜스미션케이스의 드레인플러그부위에 더 많은 손상을 준다는 것이 판명되었다. This paper is concerned with the fatigue fracture analysis of the automobile transmission case by applying road-load spectrum analysis technique. The manual transmission case receives various cyclic load and sometimes results in crack on the surface of case. Our study investigates the crack occurrence of new model which employes the three-point mounting support on transmission while previous one used three-point mounting support on engine. The crack has been detected near the drain plug for the type of three-point mounting support on transmission during the early stages of endurance test. To find out the cause quantitively, experiment and computational analysis have been carried out to calculate the cumulative damage for both support types during one cycle endurance test. The numerical results show that the type of three-point mounting support on transmission gives larger damages on the surface of transmission case than that of three-point mounting support on engine.

쾌속 3차원 조형 시스템을 활용한 장신구 제작방법의 개발

이호용,임중연,김경아,범형택 東國大學校 1998 東國論叢 Vol.37 No.-

This paper is concerned with the new production method for jewelry by using rapid prototyping system. this system can directly produce the three-dimensional prototype shape of jewelry based on CAD modeling. Recently, rapid prototyping technology has been regarded as a powerful concurrent tool for integrating design and manufacturing process. In view of this, our study focuses the attention on the new application of this technology into the prototype production of jewelry which has been manufactured almost by hand. The characteristics of various RP systems are presented and one distinct jewelry example has been produced to show that out method is quick and efficient.

사망 진단서(시체 검안서) 작성의 문제점

김규석,임용수,이중의,서길준,윤여규,어은경,염석란,정연권,이윤성 대한응급의학회 2000 대한응급의학회지 Vol.11 No.4

Background: This study was conducted to analyze the current problems in completing death certificates and to identify the correct method for completing death certificates Methods: We reviewed 262 death certificates in three hospitals from March 1 to April 30, 2000, and 119 death certificates in one hospital from March 1 to 31, 2000. We identified major and minor errors and analyzed and compared them retrospectively. Results: A total of 381 death certificates were reviewed: 59 in Seoul National University Hospital,101 in Ewha Woman's University Hospital, and 102 in Gachon Medical College Hospital, which has no education program for completing death certificates in postgraduate training, and 119 in Samsung Medical Center which has an education program for completing death certificates. 358 certificates(94.0%) had at least one error. There were only 23 death certificates(6.0%) without an error. In 182 cases(47.8%), there was one major error. In 321 death certificates(84.3%), there were more than two errors. A comparison of Samsung Medical Center with the other hospitals showed that the number of total errors was statistically different(p=0.001). Conclusion: There were few death certificates without an error in this study. In a hospital which has postgraduate training in completing death certificates, there are fewer errors than in other hospitals which have no training course. Emergency physicians actually certify many deaths, so they must know the correct method of completing death certificates for statistics on morbidity and mortality.

유한요소 방법에 의한 스트립 압연에 대한 해석

이호용,임중연,마상백 동국대학교 산업기술연구원 1997 산업기술논문집 Vol.9 No.-

실험적으로 결정된 응력-변형률 곡선과 측정된 로울-스트립(strip) 접촉면에서의 속도분포를 탄-소성 유한요소모델에 입력하여 스트립 압연에 대한 해석을 시도하였다. 변형된 로울의 형상은 수치모델에서는 원형으로 간주하였고 실제 접촉 길이에 근거하여 응력-변형률 분포와 속도장이 계산되었다. 단면감소율에 따른 로울 압하력의 유한요소해석 결과를 얻었고 이를 실험결과와 비교한 결과 근사한 일치를 보여 주었다. Experimentally determined stress-strain curve and measured roll-strip interface velocities are used as input to an elastic-finite element model of strip rolling. The shape of the deformed roll is assumed to be circular in the numercal model and is based on the actual contact length. The stress and strain distributions and velocity fields are computed. The predictions of the roll separating force for several reductions compare favorably with the experimental results.

The Methodology of Process Sequence Design in Metal Forming

Lim, Joong-Yeon,Lee, Ho Yong 동국대학교 산업기술연구원 1998 산업기술논문집 Vol.11 No.-

본 논문에서는 체계적인 소성가공의 공정설계에 대한 접근 방법론을 제시하였다. 제조공정에서의 기존 설계방법에 대한 흐름도를 보여 주었고 시간과 노력이 많이 필요함을 알 수 있었다. 이러한 시행착오를 줄이기 위하여 소성가공공정에도 컴퓨터 원용설계방법이 도입되어 솔리드 모델링, 연산속도 및 모의기법 소프트웨어 분야에서 비약적으로 발전하고 있으나 기본적인 설계기법에 대한 방법론이 체계적으로 공식화되어 있지 못하다. 따라서 여기서는 소성가공공정의 컴퓨터 원용 설계 방법론에 대한 기본적인 두 가지 방법을 요약하여 제시하였다. 소성가공에서 나타날 수 있는 다양한 지식과 문제해결기법을 이용하여 설계에서 의사결정을 이루게 해주는 지식기반시스템 접근방법과 유한요소법과 같은 수치해석적 방법을 사용하여 설계알고리즘을 세울 수 있는 해석접근방법에 대하여 기술하였다. 본 논문에서 제시한 두 가지 방법은 현재의 소성가공의 공정설계에 대한 일반적인 설계방법론의 근간을 제공해 줄 것이다.

Involvement of TGF-β1 Signaling in Cardiomyocyte Differentiation from P19CL6 Cells

Joong-Yeon Lim,Won Ho Kim,Joon Kim,Sang Ick Park 한국분자세포생물학회 2007 Molecules and cells Vol.24 No.3

Involvement of TGF-beta1 signaling in cardiomyocyte differentiation from P19CL6 cells.

Lim, Joong-Yeon,Kim, Won Ho,Kim, Joon,Park, Sang Ick Korean Society for Molecular Biology 2007 Molecules and cells Vol.24 No.3

<P>Stem cell-based therapy is being considered as an alternative treatment for cardiomyopathy. Hence understanding the basic molecular mechanisms of cardiomyocyte differentiation is important. Besides BMP or Wnt family proteins, TGF-beta family members are thought to play a role in cardiac development and differentiation. Although TGF-beta has been reported to induce cardiac differentiation in embryonic stem cells, the differential role of TGF-beta isoforms has not been elucidated. In this study, employing the DMSO-induced cardiomyocyte differentiation system using P19CL6 mouse embryonic teratocarcinoma stem cells, we investigated the TGF-beta-induced signaling pathway in cardiomyocyte differentiation. TGF-beta1, but not the other two isoforms of TGF-beta, was induced at the mRNA and protein level at an early stage of differentiation, and Smad2 phosphorylation increased in parallel with TGF-beta1 induction. Inhibition of TGF-beta1 activity with TGF-beta 1-specific neutralizing antibody reduced cell cycle arrest as well as expression of the CDK inhibitor p21WAF1. The antibody also inhibited induction of the cardiac transcription factor Nkx2.5. Taken together, these results suggest that TGF-beta1 is involved in cardiomyocyte differentiation by regulating cell cycle progression and cardiac gene expression in an autocrine or paracrine manner.</P>

세탁조의 제작공정해석 및 공정개선에 관한 연구

임중연(Joong-Yeon Lim),이호용(Ho Yong Lee),황병복(Beong-Bok Hwang) 한국소성·가공학회 1994 소성가공 : 한국소성가공학회지 Vol.3 No.3

냉간압출을 이용한 롱넥 플랜지 성형에 대한 공정설계

임중연(Joong-Yeon Lim),황병복(Beong-Bok Hwang),김철식(Chul-Sik Kim) 한국소성·가공학회 1999 소성가공 : 한국소성가공학회지 Vol.8 No.2