Failure with Strain Localization of Aluminum Alloy 7075 Sheets at Elevated Temperature and its Application to Two-Step Hybrid Forming

Jong‑Hwa Hong,Hyunki Kim,Wonjae Kim,Yong‑Nam Kwon,Daeyong Kim 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.4

In this work, the onset of failure induced by severe strain at elevated temperature was numerically estimated with crossformedempirical hardening law describing material softening. The hardening law can replicate the rate-sensitive behaviorof aluminum alloy 7075 sheets (thickness of 2.0 mm) with initial hardening and progressive material deterioration causedby dynamic recrystallization, dynamic recovery, and micro-void development. The characterized material was applied to thetwo-step hybrid forming process consisting of a drawing at 400 °C followed by a pneumatic forming at 470 °C to produce ashock absorber housing with an extremely complex shape. The user-defined subroutine codes, VUMAT (ABAQUS/Explicit)and UMAT (ABAQUS/Standard), were sequentially utilized for the drawing and the pneumatic forming, respectively. Theidentified hardening parameters based on uniaxial tensile tests were validated by simulating the two-step hybrid formingprocess and compared with the conventional Voce type law (converging function) and the combined Swift-Voce type law(ever-increasing function) since they play a key role in accurately predicting the onset of failure induced by severe strainlocalization. Finally, simulation results are reasonably well matched with experiments in terms of the moment of failureoccurrence, failure location, final blank shape, and thickness distribution.

Science and Marxism

Kim, Jong Hwa 덕성여자대학교 사회과학연구소 2004 사회과학연구 Vol.10 No.-

Scrutiny라는 계간 저널은 1932년에 창설되었는데, Cambridge 대학의 Leavis 등을 중심으로 지식인들의 토론 광장으로서의 역할을 수행하였다. 이 연구는 Scrutiny가 다른 주제와 관심사를 Scrutiny와 그에 대한 비판론자들(마르크스주의자들)의 관점에서 과학과 Marxism에 대한 명제를 중심으로 점검해 보았다. 과학과 마르크스주의 관계에 대한 주제는 Scrutiny에서 핵심적 과제로 다루어 졌는데, Scrutiny와 마르크스주의자들의 충돌은 그 저널이 마르크스주의에 개입하면서 시발되었고, 마르크스주의자들은 Scrutiny를 역사적·이념적 궤도 속으로 몰아넣으면서 비판하였다. 마르크스주의자들은 특히 Scrutiny의 정치적 요소 고려에 대한 소홀함이 여러 측면에서 불균형적 논리전개를 표출하고 현실성을 간과하였다고 지적하였다. Scrutiny는 문화의 중요성을 강조하면서 본질적으로 生의 질을 순전히 물질적 개념으로 접근하는 공리주의에 반대하는 입장이었다. 즉 Leavis 등 Scrutiny 편집자들은 생의 질을 논하는데 있어서 물질적 측면과 정신적 측면을 포괄적으로 고려하지 않으면 의미가 없다고 주장하였다. 한걸음 더 나아가, Scrutiny가 중시하는 문화란 사회변혁과 산업화로 파괴된다고 봄으로써 분명히 과학과 실용주의적 요소를 결여하게 되었고 결과적으로는 마르크스주의자들의 Scrutiny에 대한 비판도 여기에 초점이 맞추어져 있다. 생각건대 Scrutiny의 정치·사회적 문제에 대한 문화적·도덕적 관행설정으로 Scrutiny가 문화적 엘리트주의에 빠져 문화적 편중접근이라는 비난을 면하기 어렵지만, 도덕적 기준에서 보면 깊이 있게 과학과 마르크스주의를 통찰한 점은 높이 평가 되어야 할 것으로 보여진다.

CD34+ 조혈 모세포 이식 2례

김정아,정현식,김원석,윤성수,이홍기,박찬형,박성규,김동욱,이종욱,한치화,민우성,김춘추,김동집 대한조혈모세포이식학회 1996 대한조혈모세포이식학회지 Vol.1 No.1

Background: In most solid tumors, the CD34 antigen has not been detected, so positive selection of CD34+ cells may reduce tumor cell contamination and the CD34+ cells are capable of reconstituting hematopoiesis. We tried CD34+ cell transplantation in two patients. Method: CD34+ cells from chemotherapy + G-CSF mobilized PBPCs or bone marrow were positively selected with an avidin-biotin immunoadsorption column (CEPRATE SC system). Case 1. One course of chemotherapy using cyclophosphamide(200㎎/㎡) and etoposide (4.2g/㎡), combined with G-CSF(5㎍/㎏) S.C. was used in a relapsed lymphoma patient. This patient responded to the induction chemotherapy. CD34+ cells from harvested bone marrow were selected by the CellPro immunoadsorption column. The total number of mononuclear cells loaded onto the CellPro was 2.4×10^(8)/㎏, with 1.1% CD34+ cells. After column separation, the total number of positively selected cells was 5.16×10^(6)/㎏. The number of CFU-GM was 76.8×10⁴/㎏. This patient was treated with melphalan (140㎎/㎡) and TBI (1200cGy) and the positively selected CD34+ cells were infused. The time to neutrophil recovery greater than 0.5×10^(9)/L was 19 days and the time to platelet recovery greater than 50×10^(9)/L was 21 days. Case 2. Two courses of mobilizing chemotherapy were given 4 weeks apart using taxol(210㎎/m2) and adriamycin(60㎎/m2), combined with G-CSF(5㎍/㎏) S.C. in a breast cancer patients with 7 axillary node metastasis. CD34+ cells from each single leukapheresis product were selected by the CellPro immunoadsorption column. In the first collection, the total number of nucleated cells was 4.4×10^(8)/kg, with 0.42% CD34+ cells. In the second collection, the total number of nucleated cell was 2.8× 10^(8)/㎏ with 0.43% CD34+ cells. After colum separation, the total numbers of collected cells were 4.0×106/kg and 4.8×10^(6)/kg, the total number of CD34+ cells were 1.2×10^(6)/㎏ and 0.82×10^(6)/㎏. Colonogenic assays of positively selected CD34+ cells gave rise to myeloid erythroid, and multilineage colonies, with a median of 190 CFU-GM, 190 BFU-E, and 164 CFU-GEMM per 1×10³ adsorbed cells, respectively. High-dose chemotherapy with cumulative doses of 40mg/㎡ mitoxantrone, 750mg/㎡ thioptepa, and 1000mg/㎡ carboplatin was administered. Positively selected CD34+ cells were rapidly infused 24 hours after the end of high-dose chemotherapy. The time to neutrophil recovery greater than 0.5×10^(9)/L was 16 days and the time to platelet recovery greater than 50×10^(9)/L was 20 days.

해도 정보를 이용한 선박의 최적 항로 생성

김민규(Min-Kyu Kim),김종화(Jong-Hwa Kim),양현(Hyun Yang) 한국항해항만학회 2022 한국항해항만학회 학술대회논문집 Vol.2022 No.2

Min-Kyu Kim*․Jong-Hwa Kim**․†최근 자율 운항 선박에 대한 관심이 높아지고 있다. 특히, MUNIN (Maritime Unmanned Navigation through Intelligence in Networks) 프로젝트를 계기로 자율 운항 선박에 대한 개발과 연구가 활발히 진행되고 있다. 또한 국제해사기구 IMO는 자율 운항 선박 시대에대응하기 위해 자율 선박을 MASS (Maritime Autonomous Surface Ship)라 정의하고 선박 자율화 정도에 따라 4단계 등급을 제시하고 있다. 완전한 자율 운항 선박에 대한 요구조건을 만족하기 위해서는 항로 결정과 제어기술이 필수적이다. 본 연구에서는 여러 가지 기술 중 선박의최적경로를 생성하는 기법을 다룬다. 기존에 최적항로를 생성하기 위한 방법으로는   , Dijkstra와 같은 알고리즘들이 주로 사용되었다. 그러나 이와 같은 알고리즘은 섬이나 육지에 대한 충돌 회피는 고려하고 있지만 수심 및 연안 선박에 대한 규정들은 고려하지 않고 있어실제로 적용하기에는 한계점이 있다. 따라서 본 연구에서는 안전을 위해 선박의 선저 여유 수심과, 해도에 규정되어 있는 선박 운항에 대한여러 규정들을 반영하여 최적 항로를 생성하고자 한다. 최적 항로를 생성하기 위한 알고리즘으로는 강화학습 기반의 Q-learning 알고리즘을적용하였다.

고요산혈증의 위험인자 : 아산시 지역 주민을 대상으로

김용배,장원기,황보영,김화성,안규동,이병국,이용진,이종은,이준숙,이찬구,이한정,이성수 순천향대학교 2006 Journal of Soonchunhyang Medical Science Vol.12 No.1

Objective : Serum uric acid has now been identified as a marker for a number of metabolic and hemodynamic abnormalities. The aim of this study is to evaluate risk factors which influence hyperuricemia in the citizens of Asan. Method : The study design was cross-sectional and research subjects were 1086 citizens of Asan. General characteristics, cigarette smoking, alcohol consumption, and past history were obtained by interview using a structural questionnaire. Also, we measured height, weight and blood pressure, and serum uric acid of the subjects. Results : The mean serum uric acid level was 5.27 ㎎/㎗ in men and 4.01 ㎎/㎗, in women, In the multiple logistic regression analysis, statically significant risk factors of hyperuhcemia were gender, body mass index, blood lead concentration, and serum creatinine. Conclusion : Our results suggest that gender, body mass index, blood lead concentration, and serum creatinine might be the most important risk factors of hyperurcemia. Education program as well as routine check-up for serum uric acid was highly recommended for the effective prevention of hyperuricemia.

理想的인 絶綠體를 酸化膜으로 갖는 MOS diode의 等價回路

金鍾和 木浦大學校 工業技術硏究所 1992 工業技術硏究誌 Vol.2 No.-

In due consideration of every possible bias conditions and frequency regions, I propose the equivalent circuit of MOS diode which deal with carrier mobile on semiconductor including the interface, rightly (in case of n-type semiconductor). Consequently, I think that this equivalent circuit can be explaine the impedence characteristics of MOS diode at almost frequency regions and every possible states.

Rhizopus oryzae KCTC 11970을 이용한 푸마르산 생산조건의 최적화

김진남,양환승,이종일,류화원 全南大學校 觸媒硏究所 2002 觸媒硏究 論文集 Vol.23 No.-

This work was developed in several steps to find the optimum conditions of fumaric acid production by Rhizopus oryzae KCTC 11970 in flask culture. Six different carbon sources and eleven nitrogen sources were tested. CaCO_3 was used as a neutralizing agent to control pH of medium. The optimum carbon source and nitrogen source were glucose 70 g/L and ammonium sulfate 0.4 g/L, respectively. At this optimum condition, the fumaric acid concentration, yield, and volumetric productivity were 19.33 g/L, 52.8%, and 0.32 g/L/h, respectivity, after fermentation time of 60 hr.

중학생의 구강보건행태가 치아우식증에 미치는 영향 : focusing on O middle school students in Suwon 수원시 O 중학교 학생을 중심으로

김선숙,장종화 韓國學校保健學會 2000 韓國學校保健學會誌 Vol.13 No.2

The following results were obtained after data adjustment and analysis of a study consisting of self-writing, of oral check-ups and questionnaires of 356 students of the O middle school in Suwon in June of 2000. The purpose of this study was to discover the effects of the dental health types of middle school students on dental caries and to understand the specific teeth of dental health types due to educational experience. Based on such data, we want to develop a desirable educational program for middle school dental heath. 1. The DMFT index was higher in females (0.75+4.39) than males(4.99+3.67), so there was a significant difference(p=0.000) 2. The DMFT index increased from the ages of 12 (4.69+3.90), 13 (5.69+3.67), 14 (6.18+4.39) and 15(6.98+4.08) and were significantly different (p=0.011). 3. There was no difference in the DMFT index regarding the method of brushing, educational experience for dental health, oral hygiene index and plaque index in dental health types. Yet, the more snack-eating increased, the higher the DMFT index increased; thus, there was found a significant difference (p=0.006). The more fluoride use increased, the lower the DMFT index; thus, there was a significant difference (p=0.048). As for the self-awareness index of dental health, the ones who answered positively had a DMFT index of 2.14+1.83 and those who answered negatively had a DMFT index of 7.09+3.94; thus, there was a significant difference (p=0.000). 4. For those who had had educational experience in dental health, a rolling method was used in brushing, and the frequency of fluoride use was high; the self-awareness index of dental health was high as well.

B형 간염바이러스의 태아와 성인간세포에 대한 감염성 해명 연구

정태호,김성국,서화정,윤영국,임종완,차상호,Chung, Tae-Ho 慶北大學校 醫科大學 1997 慶北醫大誌 Vol.38 No.2

목적 : 사람의 태아와 성인의 간세포에 B형 간염바이러스의 감염도를 비교 분석함으로써 HBV와 간세포간의 친화도내지는 HBV 수용체에 관한 정보를 얻고자 함. 대상 및 방법 : 성인이 외상을 입어 부득이 손상된 간조직을 절제하였을 경우와 모자보건법상 임신지속이 어려운 상태에서 부인과적 수술시 21주 전후의 태아 간조직을 얻어 DMEM 을 배지로 50% 용량으로 HBsAg 양성인 사람 혈청을 가하여 5일간 체외 배양하고 병리조직학적 처리후 효소면역학적 방법으로 HBsAg 를 염색하여 바이러스의 존재 여부를 검색하였다. 결과 : 태아와 성인 간조직을 5일간 체외 배양하였을 때 그 조직상은 간조직임을 인지할 수 있었다. HBV 의 감염여부는 DAKO 사의 효소면역법으로 조사한 결과 태아의 간조직에서는 HBsAg양성부위를 발견하지 못하였으나, 성인 간조직에서는 HBsAg 양성부위가 발견되었다. 결론 : 태생 21주 전후의 태아의 간세포는 HBV 와 친화도는 아주 미약하거나 없고, 성인 간세포는 HBV에 대한 친화도가 높다. 따라서 태생 21주의 간세포에는 HBV 의 감염이 어렵다는 것을 인지하게 되었다. Considerable progress has been made in the immune prophylaxis of hepatitis B virus(HBV) infection and in the understanding of its replication and pathogenecity at the molecular level. However, a convenient in vitro assay for HBV infectivity has been lacking and the early steps of viral life cycle are now yet well understood. Primary cultured human hepatocytes are reported to be susceptible to HBV 10-12, but these systems are not practical because they are short-lived and require primary explanted human liver. However, it is uncertain yet whether primary hepatocytes of human fetal liver are susceptible to HBV for infection or not. We have expanded the infectivity of HBV into a primary cultures of human fetal hepatocytes together with controversy of adult primary hepatocytes. To investigate the infectivity of HBV for adult and fetal hepatocytes After 5 day culturing fetal(1) and adult(2) liver tissues, which obtained from a surgical operation on DMEM culture media with half HBV positive serum, separating liver cells and fixing them, the existence of HBsAg antigen was investigated through the immuno-enzymatic staining. HBsAg stained area was not found in the 21 weeks gestation liver cells until 5 days of invitro-culture, while it was found in the adult liver cells. This test result showed that the HBV infection is very hard to happen in the liver cells 21 weeks gestation or prior one.

브랜드‘더마앤모어’를 위한 스페셜 프로모션 부스 디자인 연구 - ‘프레쉬 캐주얼 스타일링’을 활용하여 -

김수안,박수빈,송혜진,이종화,이진민,장미정,이성애 숙명여자대학교 디자인연구소 2018 숙명디자인학 연구 Vol.25 No.-

본 연구는 (주)애경과 S여대와 산학연계하여 진행한 브랜딩 스타일링 마케팅 기획 프로세스를 체계적으로 정리하는데 목적이 있다. 이에 본 연구는 2017년 9월~12월까지 환경디자인학과 ‘브랜딩·스타일링·마케팅’ 교과목에서 진행한 내용을 대상으로 하며 국내 샴푸브랜드 ‘더마앤모어’를 분석하여 디자인 개념을 결합하고 부스 디자인을 제시하는 과정들을 밝힌다. 이를 통해 본 연구는 향후 생활용품 브랜드의 디자인 개발에 있어서 창의적인 부스디자인의 방향성을 제시한다. 본 연구의 방법은 공간 브랜딩에 대한 이론적 고찰을 통해 브랜딩 스타일링 마케팅 프로세스의 스타일 분석, 디자인 개발, 공간 디스플레이 연출로 구성하여 그 과정을 밝힌다. 끝으로 본 연구는 대학과 산업체간의 연계를 통한 교과목 개발에 활용되는데 의의가 있다.