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.

The Effects of Optic Disc Factors on Retinal Nerve Fiber Layer Thickness Measurement in Children

Jong‐,Hwa Jun,Se‐,Youp Lee 대한안과학회 2008 Korean Journal of Ophthalmology Vol.22 No.2

Purpose: We analyzed the effect of the changes of the optic disc area (ODA) caused by the axial length and the refractive error, and the consequent changes of the distance from the optic disc margin to the circular scan (OD‐CS) of Optical coherence tomography (OCT) on the measurement of the retinal nerve fiber layer thickness(RNFLT) were examined. Methods: One hundred two eyes of 51 children (age range 4 to 15 years) were measured using OCT including the RNFLT. For the ODA and the OD‐CS, the relative area formed by the ODA and the circular scan was obtained. In addition, the correlation of the refractive error and the axial length to the optic disc factors was assessed. Results: As hyperopia progresses to myopia, the axial length became longer, the ODA became smaller (r=‐ 0.442, p=0.000) and the OD‐CS showed a tendency to increase (r=0.471, p=0.000). As the OD‐CS became longer, the measured average RNFLT decreased significantly (r=‐0.248, p=0.012), and the ODA and the ODCS showed a significant correlation to the RNFL thickness that was measured in the nasal and inferior areas, the S2, N2 and N3 areas and the I1 area. Conclusions: As ODA becomes smaller and the OD‐CS becomes longer, the RNFLT measured in the nasal and inferior areas, the S2, N2, N3, I1 area has a tendency to be thinner. Hence, consideration of the disc area is required when interpreting the RNFLT of these eyes. Korean Journal of Ophthalmology 22(2):115-122, 2008

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.

영어학습자를 위한 의문문 억양지도 방안

이종화 대한언어학회 1995 언어학 Vol.3 No.-

Lee, Jong-hwa(1995). A Proposal for the Teaching Method of English Intonation in Interrogative Sentences. Linguistics, Vol 3. The purpose of this paper is to predict the problems Korean students might have in learning English intonation of interrogative sentences, to ascertain the problems through acoustic experiment, and to propose an efficient teaching method of English intonation in interrogative sentences. High speed speech analysis system using personal computer(PC) is used in this experiment to get acoustic data. Three interrogative sentences of different patterns are selected: wh-question, yes-no question and alternative question. A native American speaker is asked to pronounce the above sentences to make the model English intonation contour of each sentence. Two Korean subjects are asked to speak the above model utterances of general American speaker's and then to pronounce them five times to ten times again, identifying their errored intonation contours. It is to compare the English intonation contours of interrogative sentences between the general American speaker and the selected Korean subject, and to propose an efficient teaching method of English intonation in interrogative sentences. As a corollarry this paper recommends that the high speed speech analysis system using PC be very useful and efficient in correcting Korean student's errors of English intonation in interrogative sentences.

Code-switching and cognitive models of the process of simultaneous interpreting

Won, Jong-Hwa 한국통역번역학회 2007 통역과 번역 Vol.9 No.2

Won, Jong-Hwa. (2007). Code-switching and cognitive models of the process of simultaneous interpreting. Conference Interpretation and Translation, 9(2), 89-112. Bilingual code-switching has long been recognized as an important linguistic phenomenon worthy of serious investigation. Code-switching is a special skill possessed by bilinguals which allows them to switch from one language to another in the course of a communicative exchange without slowing down speech delivery. The process involves the integration of the morphological, phonological, and syntactic structures of the two codes or languages in real time. Code-switching is a particularly vital aspect of the behavior of the simultaneous interpreters. Indeed, one of the major defining characteristics of simultaneous interpreting is that it inevitably involves code-switching in which switches occur moment by moment not only by the speakers but by the interpreters themselves. Code-switching can also be said to occur when interpreters listen in one language and delivers in another. Few interpreting models formulated so far, however, have incorporated the code-switching process, with the result that simultaneous interpreting is presented as a strict, linear, one-way process. This paper asks the question “To what extent should the theory of code-switching be drawn upon in describing and explaining the process of simultaneous interpreting?” and a tentative answer is offered by integrating the switching process into Setton’s (1999) simultaneous interpreting model. Keywords: Code-switching, mental lexicon, parsing, executive, frame

아산시 송악저수지의 수질오염 현황 및 부영양화 저감방안 연구

손부순,염윤기,이종화,장봉기,박종안 순천향대학교 기초과학연구소 1998 순천향자연과학연구 논문집 Vol.4 No.2

This study was conducted to estimate the water pollution load, water quantity and quality of inflow stream, status of water pollution and reduction of eutrophication in the Song-ak lake in Asan city. Inflow of branch to Song-ak lake has three streams, one is Eu-gok stream which has the most width of inflow area and another is Dong-hwa stream and the other is Ma-gok stream. The sampling numbers for water quality are 30 points from the sediment of bottom in the Song-ak lake from June, 1997 to ay, 1998. Water quality had been tested for water temperature, pH, dissolved oxygen(DO), chemical oxygen demand(COD), suspended solid(SS), total nitrogen(T-N), total phosphorus(T-P), colony numbers of E. coli, chlorophyll-α. The total nitrogen, total phosphorus and heavy metals(Fe, Pb, Cd) were analyzed by the migration test of the sediment. The results were as follows; The rate of water pollution by the livestock wastewater of the total water pollution load for BOD, SS, T-N and T-P were 59.8%, 82.9%, 56.1% and 90.6%, respectively. Mean daily inflow was 25,369m3. Quantity of inflow was highest at Eu-gok stream. The mean levels of pH, DO, COD, SS, T-N, and colony numbers of E. coli of the inflow water were 7.52, 10.25mg/ℓ, 2.12 mg/ℓ, 3.03 mg/ℓ, 2.25 mg/ℓ, 0.11 mg/ℓ and 1,795/100㎖, respectively. The worst inflow water quality was observed at Dong-hwa stream. The mean levels of pH, DO, COD, SS, T-N, T-P, T-N/T-P and colony numbers of E. coli at Song-ak lake were 8.06, 9.32mg/ℓ, 6.83 mg/ℓ, 4.78 mg/ℓ, 1.66 mg/ℓ, 0.115 mg/ℓ, 20.75 and 64/100㎖, respectively. these are higher than class IV by environmental water quality standards for lake. Mean level of trophic state index was 59.4. The mean levels of T-N, T-P, Fe and Pb by migration test of sediment at Song-ak lake were 259.7ppm, 10.546ppm, 1,704ppm and 8.54ppm, respectively. As the water pollution was mainly caused by livestock waste, the strategy for the reduction of eutrophication of the Song-ak lake should be concentrated on the control of the livestock waste.

HIV 감염/AIDS을 처음 진단받은 환자들의 특성과 임상에서 보편적인 HIV 검진의 가치

김종화,김태형,추은주,전민혁,서성우,이용관,최문한 순천향의학연구소 2008 Journal of Soonchunhyang Medical Science Vol.14 No.2

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면역조직화학적 방법을 이용한 흰쥐 골격근 근섬유형의 비교연구

이종은,이원택,박승화,박경아 대한해부학회 1994 Anatomy & Cell Biology Vol.27 No.3

[논문]부산광역시 지하철역의 오염물질 농도 변화에 관한 연구

이화운,박종길,장난심,이희령,김희만 부산대학교 환경문제연구소 2004 環境硏究報 Vol.22 No.-

on the variation of Air Pollutants concentration in Subway Station at Busan Metropolitan City

충북대학교 학내 버섯 분포상

이종혁, 박성웅, 이화용 충북대학교 농업과학기술연구소 2022 農業科學硏究 Vol.38 No.2

Mushroom refers to a group that forms a visual-sized body among fungi, and they are clas- sified into basidiomycetes and ascomycetes. The Chungbuk National University campus is composed of small forests and gardens, so the habitats are diverse. In this study, we investigated the occurrence of mushrooms in the Chungbuk National University campus . The mushroom occurrence monitoring was carried out at 8 sites in the campus from May to October 2021. Total 42 families 80 genera 150 species were investigated in the campus during monitoring period. They are also divided into 90 saprophytic mushrooms, 59 ectomycorrhizal mushrooms and one of unknown species of nutrition acquisition In the future, it is expected to contribute to find forest mushroom resources and understand the ecosystem change in the campus.