Development of automotive engine cradle by hydroforming process

김기주,J. S. Kim,B. I. Choi,K. H. Kim,H. H. Choi,C. W. Kim,K. W. Kang,J. H. Song,C. W. Sung 대한기계학회 2007 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.21 No.10

The hydroforming technology may bring many advantages to automotive applications in terms of better structural integrity of the parts, lower cost from fewer part count, material saving, weight reduction, lower springback, improved strength and durability and design flexibility. In this study, the whole process of front sub-frame parts development by tube hydroforming using steel material having tensile strength of 440 MPa grade is presented. At the part design stage, it requires feasibility study and process design aided by CAE (Computer Aided Design) to confirm hydroformability in details. Effects of parameters such as internal pressure, axial feeding and geometry shape in automotive engine cradle by the hydroforming process were carefully investigated. Overall possibility of hydroformable engine cradle parts could be examined by cross sectional analyses. Moreover, it is essential to ensure the formability of tube material on every forming step such as pre-bending, preforming and hydroforming. At the die design stage, all the components of prototyping tool are designed and interference with the press is examined from the point of deformed geometry and local thinning.

혈구탐식성 림프조직구증의 임상적 특징과 생존에 미치는 예후인자

김기주,김기환,이택진,전진경,유철주,김동수,Kim, Khi Joo,Kim, Ki Hwan,Lee, Taek Jin,Chun, Jin-Kyong,Lyu, Chuhl Joo,Kim, Dong Soo 대한소아청소년과학회 2008 Clinical and Experimental Pediatrics (CEP) Vol.51 No.3

Purpose : Hemophagocytic lymphohistiocytosis (HLH) is a rare but fatal disorder characterized by fever, splenomegaly, pancytopenia, and hemophagocytosis in the bone marrow and other tissues. In this study, we investigated the clinical manifestations and prognostic factors in patients with HLH. Methods : We retrospectively analyzed the data from 29 patients who were diagnosed whit HLH in the Severance Children's Hospital from Jan. 1996 to Feb. 2007. Results : The median age at diagnosis was 3.8 years (range 0.1-12.2). The ratio of male to female patients was 1.1:1. The 5-year overall survival rate was 55.2% with a median follow-up duration of 32 months. In a multivariate analysis, the duration of fever before admission (survival vs. non-survival, 6.5 days vs. 14 days, P=0.010), the interval from the day of fever onset to the day of initiation of etoposide (survival vs. non-survival, 10 days vs. 35 days, P=0.002) and the presence of neurologic symptoms (survival vs. non-survival, 1 case vs. 7 cases, P=0.010) were independent, poor prognostic factors of HLH. EBV infection, gender, and the level of serum ferritin had no relations to the poor prognosis of the disease. Conclusion : This study showed that the presence of neurologic symptoms and a longer duration of fever were related to a poor prognosis. Therefore, if a patient develops neurologic symptoms and the duration of fever is prolonged, a prompt diagnostic approach and aggressive treatment for HLH are necessary. 목 적 : HLH은 발열, 범혈구감소증, 비종대, 골수에서의 혈구탐식을 특징으로 하는 질환으로 생존율이 낮고 급격한 진행양상을 보이는 비교적 드문 질환으로 생존율에 영향을 미치는 인자들을 알아보고자 본 연구를 시행하였다. 방 법 : 1996년 1월부터 2007년 2월까지 세브란스 어린이 병원에 내원하여 HLH로 진단된 환아들을 대상으로 진료기록을 토대로 후향적으로 연구를 진행하였다. 결 과 : HLH로 진단된 환아는 총 29명이었고(남아 15명, 여아 14명) 연령의 중앙값은 3.8(0.1-12.2)세였다. 가족력이 있었던 환아는 2례였다. 29명 환아의 5년 생존율은 55.2%였다. 생존군과 사망군의 통계학적으로 유의한 차이가 있었던 소견으로는 입원전 발열기간, 처음 발열일부터 etoposide를 투여시작까지의 기간 및 신경학적 이상 유무가 있었다. 입원전 발열기간은 생존환아에서는 6.5(2-21)일이었고 사망환아에서는 14(5-60)일이었으며(P=0.010) 처음 발열일부터 etoposide를 사용하기까지의 기간은 생존환아에서는 10(8-23)일, 사망환아에서는 35(15-84)일이었다(P=0.002). 또한 신경학적 이상은 생존환아에서는 1례 있었고 사망환아에서는 7례가 있었다(P=0.010). 결 론 : HLH은 발열을 주증상으로 간비비대나 범혈구 감소증, 경련이나 의식의 장애와 같은 신경학적 증상을 동반할 수 있는 질환으로 환아가 발열기간이 길거나 신경학적 증상이 발병할 경우에는 HLH의 예후가 나쁘므로 HLH 의심 시 신속한 진단적 접근과 함께 조기의 적극적인 치료가 필요할 것으로 생각된다.

자동차용 알루미늄 5185-폴리프로필렌 샌드위치 판재의 성형성

김기주,정효태,손일선,김철웅,김중배,Kim, Kee-Joo,Jeong, Hyo-Tae,Sohn, Il-Seon,Kim, Cheol-Woong,Kim, Joong-Bae 한국자동차공학회 2007 한국 자동차공학회논문집 Vol.15 No.2

The objective of this study was to develop formability evaluation techniques in order to apply aluminum sandwich panel for automotive body parts. For this purpose, newly adopting formability evaluation (using limit dome height and plane strain test) was carried out in order to secure the fundamental data for the measurement of sheet metal forming and the establishment of optimum forming conditions of the aluminum sandwich panel. The results showed that there were good agreements between the old formability evaluation method and the new method which was more simplified than that of old one. From the results of these formability evaluation, the formability of sandwich panel was higher than that of aluminum alloy sheet alone which was the skin component for the sandwich panel. Also, it was found that sandwich panel could reduce the weight and could have the same flexural rigidity simultaneously when it was compared to the automotive steel sheet.

알루미늄 티타네이트 세라믹스에 있어서 첨가제 첨가에 따른 고온변형 특성연구

김기주,윤상로 ( Ki Ju Kim,Sang Ro Yoon ) 한국화학공학회 1995 화학공학의이론과응용 Vol.1 No.2

다양한 신질환을 가진 소아에서 Cystatin C 검사의 임상적 유용성

김기주,김정아,신재일,황유식,정일천,임종백,이재승,Kim, Khi-Joo,Kim, Joung-A,Shin, Jae-Il,Hwang, You-Sik,Cheung, Il-Chun,Lim, Jong-Baeck,Lee, Jae-Seung 대한소아신장학회 2007 Childhood kidney diseases Vol.11 No.2

목 적 :사구체 여과율은 신손상 정도와 진행을 예측하는데 중요한 척도이다. 현재까지는 혈청 creatinine을 광범위하게 사용하고 있으나 creatinine의 많은 단점으로 인해 새로운 내부표지자의 필요성이 대두되었고 cystatin C가 새로운 신기능 지표로 주목을 받고 있다. 이에 본 연구는 cystatin C의 유용성을 확인하고자 creatinine과 비교하여 연구를 진행하였다. 방 법 : 2004년 8월부터 2006년 12월까지 연세대학교 세브란스 병원 소아과를 내원한 환자들로서 다양한 신질환을 가지고 있는 43명(총 검사 횟수는 60회)을 대상으로 하였으며 creatinine, cystain C, creatinine 청소율을 측정하였고 creatinine 청소율이 감소된 환자를 그 정도에 따라 3군(Group 1 CrCl < 40mL/min/$1.73m^2$, Group 2 :CrCl 40-60 mL/min/$1.73m^2$, Group 3 : CrCl >60 mL/min/$1.73m^2$)으로 나누어 비교하였다. 결과 : Creatinine 청소율과 1/cystatin C 및 1/creatinine의 상관성을 분석하였고 각각의 상관계수는 0.685(P<0.01)와 0.640(P<0.01)이였다. Creatinine 청소율이 80 mL/min/$1.73m^2$ 이하로 감소함을 검출할 진단적 정확도는 ROC curve로 분석한 결과 AUC가 cystatin C와 creatinine에서 각각 0.829, 0.826로 큰 차이를 보이지 않았다(P=0.848). Creatinine clearance가 40 mL/min/$1.73m^2$ 이상에서는 cystatin C가 creatinine보다 높은 민감도를 보이고 있었다(Group 1 : 100% vs. 100%, Group 2 : 70% vs. 35%, Group 3 : 46% vs. 15%). 결론 : Cystatin C는 사구체 여과율을 측정하기 위한 유용한 내부 표지자이며 신기능 손상을 creatinine 보다 일찍 발견할 수 있다는 점에서 향후 신손상 검출을 위한 선별 검사로서 유용성이 높을 것으로 생각된다. Purpose : GFR(glomerular filtration rate) is a fundamental parameter in detecting renal impairment and predicts the progression of renal disease. Because serum creatinine has several disadvantages, serum cystatin C has been recently proposed as a new endogenous marker for GFR. We compared serum cystatin C with creatinine and creatinine clearance to investigate the clinical usefulness of cystatin C. Methods : We retrospectively analyzed 46 patients(60 case numbers) who had various renal diseases and classified them into 3 groups according to creatinine clearance(Group 1 : CrCl <40 mL/min/$1.73m^2$, Group 2 : CrCl 40-60 mL/min/$1.73m^2$, Group 3 CrCl >60 mL/min/$1.73m^2$). We measured serum creatinine, cystatin C and creatinine clearance and also analyzed the correlations among them. Results : Serum cystatin C and creatinine showed a similar correlation to creatinine clearance (r=0.685, r=0.640, respectively) and showed similar diagnostic accuracy in detecting decreased GFR(AUC, cystatin C 0.829 vs. creatinine 0.826, P=0.848). Serum cystatin C showed a greater sensitivity for detecting a decreased GFR than creatinine in Group 2 and 3(Group 1 : 100% vs. 100%, Group 2 : 70% vs. 35%, Group 3 : 46% vs. 15%). Conclusions : Serum cystatin C could be a useful endogenous marker for GFR and would be superior to serum creatinine in early detection of renal impairment in pediatric patients with renal diseases.

Salmonella enterica serovars Enteritidis의 온도감수성 변이주 및 폴리인산키나아제 변이주의 제작과 방어효과

김기주,박소연,조영재,곽정연,강정무,김은희,최환원,원호근,노윤희,한태욱,Kim, Kiju,Park, Soyeon,Cho, Youngjae,Kwak, Jeong-Yeon,Kang, Zheng-Wu,Kim, Eun-Hee,Choi, Hwan-Won,Won, Ho-Keun,Noh, Yun-Hee,Hahn, Tae-Wook 대한수의학회 2013 大韓獸醫學會誌 Vol.53 No.4

This study was focusing on evaluating the protection of polyphosphate kinase (ppk) deleted and/or temperature-sensitive (ts) Salmonella Enteritidis (SE) as an attenuated vaccine in chickens. We constructed SEppk, SEts and SEppk::ts mutants and screened those mutants by growth capability in vitro, protection study in mice model and antibody response in chickens. Among the mutants, SEppk::ts-3 was selected because it showed higher growth capability, good protection against highly virulent SE in mice model, and good antibody response in chickens. SEppk::ts-3 also showed good protection against highly virulent SE isolate because it decreased colonization of virulent SE challenge strain in spleen, liver and cecum compared with the non-vaccinated control. The SEppk::ts-3 mutant showed cross-protection against S. Gallinarum (SG) challenge although the its cross-protection rate was a little lower than that of SG9R, a commercial vaccine against SG infection. To use for live attenuated vaccine in chickens, it should further be characterized.

Salmonella enterica serovars Enteritidis, Gallinarum 및 Typhimurium의 마우스 면역반응의 비교평가

김기주,김두리,선지선,박소연,조영재,고현정,주홍구,한태욱,Kim, Kiju,Kim, Dooree,Sun, Jisun,Park, Soyeon,Cho, Youngjae,Ko, Hyun-Jeong,Joo, Hong-Gu,Hahn, Tae-Wook 대한수의학회 2013 大韓獸醫學會誌 Vol.53 No.2

The study was carried out to evaluate and compare the immune responses in mice experimentally infected with either wild-type or isogenic mutants of Salmonella enterica serovars Enteritidis (SE), Salmonella Typhimurium (ST) and Gallinarum (SG). The mutant strains were constructed by allelic replacement of some virulence-associated genes in the wild-type strains. Seven-week-old female BALB/c mice were orally or intraperitoneally inoculated by injecting bacterial suspension. To evaluate the immune responses, enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot (ELISPOT) assay were conducted with serum and fecal samples. As a result, the mice group infected orally with the SE mutant strain showed the highest level of specific IgA-secreting splenocytes, compared to the other groups. The peritoneally injected groups showed the greater levels of IgG1 than the orally injected groups, which was in a good agreement with the previous studies. In addition, the mutant infected groups had the similar secretion levels of antibodies with the wild-type infected groups. These results demonstrated that the SE mutant strain elicited humoral immune response as much as wild-type, implying that it can be useful as a delivery vehicle as well as a candidate of a live attenuated vaccine.

정상 한우 및 번식장애 한우에 대한 자궁 내 세균 분석

김기주,박소연,조영재,정배동,박정준,한태욱,Kim, Kiju,Park, Soyeon,Cho, Youngjae,Jung, Bae-Dong,Park, Joung-Jun,Hahn, Tae-Wook 대한수의학회 2014 大韓獸醫學會誌 Vol.54 No.4

Uterine sterilization is important for improving fertility in cattle. This study compared bacterial flora in the uterus between healthy and repeat breeder cows (RBCs). The uterine flushing of six heifers, 13 healthy HanWoo cows and eight RBCs (HanWoo) were sampled, and 15 frozen semen samples were selected. Overall, 35 bacteria were identified from in HanWoo uterine flushing and semen. The bacterial genera identified from HanWoo uterine flushing were Alloiococcus, Bacillus, Enterobacter, Enterococcus, Erysipelothrix, Gardnerella, Granulicatella, Kocuria, Pantoea, Pasteurella, Rothia, Serratia, Sphingomonas, Staphylococcus, Stenotrophomonas and Streptococcus. The bacterial genera identified from HanWoo semen were Bacillus, Escherichia, Kocuria, Oligella, Pseudomonas, Serratia, Sphingomonas, Staphylococcus, Stenotrophomonas and Streptococcus. The prevalence and presence of the identified bacteria between healthy cows and RBCs differed significantly. Further studies are needed to determine the role of these bacteria in the uterus of HanWoo cattle with reproductive disorder.

효율적인 화상회의 동영상 압축을 위한 블록기반 얼굴 검출 방식

김기주,방경구,문정미,김재호,Kim, Ki-Ju,Bang, Kyoung-Gu,Moon, Jeong-Mee,Kim, Jae-Ho 한국통신학회 2004 韓國通信學會論文誌 Vol.29 No.9C

We propose a new fast, algorithm which is used for detecting frontal face in the frequency domain based on human skin-color using OCT coefficient of dynamic image compression and skin color information. The region where each pixel has a value of skin-color were extracted from U and V value based on DCT coefficient obtained in the process of Image compression using skin-color map in the Y, U, V color space A morphological filter and labeling method are used to eliminate noise in the resulting image We propose the algorithm to detect fastly human face that estimate the directional feature and variance of luminance block of human skin-color Then Extraction of face was completed adaptively on both background have the object analogous to skin-color and background is simple in the proposed algorithm The performance of face detection algorithm is illustrated by some simulation results earned out on various races We confined that a success rate of 94 % was achieved from the experimental results. 비디오화상회의 시스템을 위하여 동영상 압축 DCT 계수와 피부색정보를 이용하여 주파수 영역에서 정연 얼굴 을 실시간으로 검출하는 알고리즘을 제안한다. 동영상 압축과정 중에 얻어지는 DCT계수 값의 U 와 V 색상정보로 피부색 범위를 추출하며 잡음성분제거를 위해 형태학적필터와 Labeling을 적용하고 피부색블록의 방향성과 평탄도를 고려하여 검출하였다. 제안 알고리즘은, 배경에 피부색과 유사한 객체가 있는 경우와 배경이 단순한 경우에 대 해 적응적으로 검출이 가능하도록 하였다 여러 인종에 대한 모의실험결과 제안 알고리즘이 약 94% 의 검출 성공률을 보였다.

알칼리 용액중 디 - 하이드로 옥시 벤젠에 의한 알미늄판 부식억제효과

김기주,조종현 ( K . J . Kim,J . H . Cho ) 한국부식방식학회 1982 Corrosion Science and Technology Vol.11 No.1