Microstructure, Tensile and Fatigue Properties of Al–5 wt.%Mg Alloy Manufactured by Twin Roll Strip Casting

Joon‑Young Heo,Min‑Seok Baek,Kwang‑Jun Euh,Kee‑Ahn Lee 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.5

This study investigated the microstructure, tensile and fatigue properties of Al–5 wt.%Mg alloy manufactured by twin rollstrip casting. Strips cast as a fabricated (F) specimen and a specimen heat treated (O) at 400 °C/5 h were produced andcompared. In the F specimen, microstructural observation discovered clustered precipitates in the center area, while in theO specimen precipitates were relatively more evenly distributed. Al, Al 6 (Mn, Fe), Mg 2 Al 3 and Mg 2 Si phases were observed. However, most of the Mg 2 Al 3 phase in the heat-treated O specimen was dissolved. A room temperature tensile test measuredyield strength of 177.7 MPa, ultimate tensile strength of 286.1 MPa and elongation of 11.1% in the F specimen and167.7 MPa (YS), 301.5 MPa (UTS) and 24.6% (EL) in the O specimen. A high cycle fatigue test measured a fatigue limit of145 MPa in the F specimen and 165 MPa in the O specimen, and the O specimen achieved greater fatigue properties in allfatigue stress conditions. The tensile and fatigue fracture surfaces of the above-mentioned specimens were observed, and thisstudy attempted to investigate the tensile and fatigue deformation behavior of strip cast Al–5 wt.%Mg based on the fi ndings.

공매도의 수익률예측성과 미래이익반응계수에 관한 연구

이용석(Lee, Yong-Seok),박희진(Park, Hee-Jin),김범준(Kim, Bum-Joon) 한국국제회계학회 2018 국제회계연구 Vol.0 No.78

본 연구의 목적은 기업별 공매도 체결내역을 기초로 공매도 거래와 회계정보의 유용성 간의 관련성을 분석하는 것이다. 일반적인 주식투자에 비해 공매도는 상대적으로 위험이 큰 투자안이므로 공매도 투자자는 위험을 회피하기 위하여 보다 적극적으로 회계정보를 활용할 가능성이 높다. 이에 본 연구에서는 공매도 투자자가 공매도 거래시 기업의 영업성과와 관련된 회계정보를 어떻게 활용하는지를 살펴보았으며, 추가적으로 FERC 모형을 이용하여 거래비중이 높은 기업에서 당기 주식수익률이 미래이익을 보다 정확하게 반영하고 있는지를 분석하였다. 분석결과, 투자자가 공매도 거래시 기업의 영업성과와 관련된 회계정보를 이용하여 추가적인 양(+)의 초과수익을 달성할 수 있음을 확인하였으며, 이를 통해 공매도 투자시 회계정보를 활용할 충분한 유인이 존재함을 보였다. 아울러 공매도 거래비중이 높은 기업에서 당기주식수익율과 미래이익간의 양(+)의 관련성이 더 높은 것으로 나타나, 공매도 거래비중이 높은 기업일수록 당기수익율이 보다 정확하게 미래이익을 반영하고 있다는 점을 실증적으로 제시하였다. 공매도는 전문적 투자자가 투자대상기업의 내재가치 변경을 예상할 때 발생한다는 선행연구의 결과와 유사하게 본 연구는 공매도 투자시 투자기업의 회계정보가 투자의사 결정의 유용한 정보가 될 수 있음을 보였으며, 공매도 투자자가 기업의 미래수익률을 보다 정확하게 예측한다는 Drake et al.(2011)의 연구결과가 국내 주식시장에서도 일관되게 나타난다는 점을 확인하였다. 공매도 거래비중이 높은 기업일수록 기업의 미래이익반응계수가 상대적으로 높은 것으로 나타났는데 이는 공매도 투자자들이 자본시장에서 회계정보를 잘 이용하게 할 수 있는 정보 촉매제 역할을 하고 있음을 시사하는 것으로 Pownall and Simko(2005)의 주장과도 일치되며, 직접적인 공매도거래가 아닌 대차잔고를 이용하여 연구를 실시한 Drake et. al.(2015)의 연구결과와도 유사한 결과이다. 본 연구는 자본시장에서 공매도 투자자가 정보중개인의 역할을 수행하고 있다는 점을 밝혔으며, 아직까지 공매도에 대한 인식에 차이가 존재하는 금융당국 · 투자자 및 기업들에게 공매도에 대한 유용한 새로운 시각을 제공한다. The purpose of our study is to analyze the relationship between the short sale transaction and the usefulness of accounting information based on the short sales transaction data. Since short selling is relatively high risk compared to stock trading, short selling investors are more likely to actively use accounting information to avoid risk. In this study, we investigate whether short selling investors use accounting information related to the company"s performance when doing short selling. In addition, we use the FERC model to analyze whether the current profitability is more accurately reflect future profit. According to the result of our analysis, investors can obtain additional positive earnings by using the accounting information related to the performance of the company during the short sale. Therefore, we find that there is sufficient incentive to utilize the accounting information in the short sale investment. In addition, the relationship between the future profit and the stock return is higher in companies with a high volume of short selling, suggesting that firms with higher volume of short selling would likely to reflect future earnings more accurately in the current stock return. Based on the prior research that short selling can be occurred when a professional investor expects to change the intrinsic value of firm, this study shows that the accounting information can be useful for investment decision. In addition, we also find that short-selling investors, who can be regarded as professional investors, predict the firm’s future returns more accurately, confirming that the empirical results of Drake et al. (2011) consistently apply in Korea stock market. Our results are consistent with the finding of Pownall and Simko (2005), which shows that firms with high short-sale volume have relatively high future earning-response coefficients, suggesting that short-selling investors have a role as information catalysts. We find that short selling investors play the role of information intermediaries in the capital market and provide a new insight on short selling to financial authorities and investors who still have differences perspectives in short selling transaction.

[논문]실시간 정밀 3차원 지형측량기법을 이용한 저수량산출시스템 개발

송석진,장용구,김상석,강인준 釜山大學校生産技術硏究所 2004 生産技術硏究所論文集 Vol.63 No.-

현재 고정밀도 저수량 측량에 사용되는 측량장비에는 수평위치결정방법으로 실시간 DGPS측량장비가 많이 활용되고 있고, 수심측량에는 디지털 음향측심기를 많이 사용하고 있다. 본 연구에서는 현재, 수심측량 결과처리 시 문제가 되고 있는 소프트웨어의 가격부담을 줄이고 수심측량과 내업처리에 의한 저수량산출을 통합처리 할 수 있는 국내 자체개발의 저가형 외 · 내업 일체형 저수량산출시스댐을 개발하였다.

흰쥐 뇌에서 Neuropeptide-Y 분비세포의 출현시기 및 발육에 관한 면역조직화학적 연구

모근석,김종중,정윤영,장인엽,문정석,김준수,김흥중 대한해부학회 1996 Anatomy & Cell Biology Vol.29 No.5

순천향대학교 천안병원에 입원한 로타바이러스 감염 위장관염 환자의 임상양상

최석주,전세윤,김승수,박경배,김용배,박준수 순천향의학연구소 2006 Journal of Soonchunhyang Medical Science Vol.12 No.1

..

고양이 중뇌 흑색질의 Dopamine 면역반응세포에 관한 면역세포화학적 연구

모근석,문정석,김종중,김준수,정윤영,장인엽,김흥중 대한해부학회 1996 Anatomy & Cell Biology Vol.29 No.5

두경부에 발생한 방선균증 3예

홍석중,주준범,김용재,이봉재 대한이비인후과학회 2000 대한이비인후과학회지 두경부외과학 Vol.43 No.11

부산지역 제조업 공동화 현상에 대한 일 고찰

김석준 부산대학교 사범대학 1996 교사교육연구 Vol.33 No.-

The purpose of this paper is to investigate the realities of deindustrialization which has been going on rapidly since 1990s in Pusan city and to examine the influences of such deindustrialization upon the region. The findings of this study can be summarized as follows. 1) With the advent of the 1990s the economic recession of Pusan city has deepened because of the deindustrialization and the outflow of money. Consequently the quality of life of the Pusan citizen went from bad to worse. 2) During the period between 1990 and 1995, 7,249 factories were disappeared in Pusan city. Among them 4,240 factories(58.2%) gave up their business and 2,136 factories(29.5%) were dishonored. 612 factories(8.4%) moved out to neighboring region and 261 factories(3.6%) went abroad. Those factories which were disappeared since 1992 amounted about 15% of total factories in Pusan city. 3) Deindustrialization brought about rapid shrink of the mining and manufacturing industries and remarkable growth of the service industry. This change of industrial structure caused the change of class composition. The proportion of working class decreased and that of middle strata increased rapidly. This change of class composition was peculiar to Pusan city. On the other hand, deindustrialization caused the reduction of the average size of factories and accelerated the growth of 'the less than five person factory'. Those people who work at 'the less than five person factory' became the so-called 'stagnant overpopulation'. They degenerated the working conditions of laborer in Pusan city. 4) Many projects were promoted in order to overcome such a serious deindustrialization and to escape from the longstanding economic recession. 'Construction of Samsung Motor Company', 'Enticement of 2002 Asian Game', 'Gaduck Island new port development plan' were well known examples. Such projects would have significant impact on regional economy. But they could not solve the major problems caused by the deindustrialization. In order to activate the regional economy and improve the quality of life of grassroots, a kind of alternative approach to regional development is required. The essence of this approach may be to overcome 'the urbanization of capital' by 'the bottom-up strategy'.

부산지역 중학생들의 일상생활과 의식에 관한 조사보고

김석준 부산대학교 사범대학 1995 교사교육연구 Vol.30 No.-

The purpose of this paper was to analyse the conditions and consciousness of middle school students in Pusan City. The subjects of this study were 834 students extracted from 16 middle schools by random sampling. The findings of this study can be summarized as follows. (1) Middle school students in Pusan city study about 2 hours and 20 minutes a day in addition to the regular school classes. They also watch TV about 2 and a half hour a day which is a little longer than the length of studying. (2) 54% of middle school students in Pusan city attend institution lectures or receive private lessons, and the fee of these lessons total over 120,000￦ a month. Middle school students take these extra lectures to improve at subjects which they do poorly, but they don't believe these to be very effective. (3) The serious problems that plague middle school students in Pusan city are 'scholastic achievements' (51.7%), 'decision about how to live' (14.6%), 'friendship' (8.1%) and so on. And their counselors are 'friends' (40.9%), 'mother' (16.9%), 'father' (4.6%), 'teacher' (0.5%), and 'nobody' (21.9%). (4) The middle school students in Pusan city make frequent visits to arcades, video stores, singing rooms, or comic book rooms. Many students also experienced the following : 'fistfight' (50%), 'cheating in exams' (40%), 'drinking alcohol' and 'breaking things' (30%), 'stealing goods' (15%), 'robbing someone of goods' (10%). In addition, about 50% of them have thought of committing suicide, and about 10% of them often think that they would like to die. (5) In respond to the question about the attitude toward 'life as a whole', the middle school students in Pusan city answered as follows : 'very satisfied' (5.8%), 'satisfied' (33.9%), 'so so' (35.0%), 'not satisfied' (19.6%), 'never satisfied' (5.6%). This result shows us that the degree of satisfaction about 'life as a whole' is relatively high. While the degree of satisfaction in 'home life' or 'friendship' is much higher than the degree of satisfaction in 'life as a whole', the degree of satisfaction in 'school life' and 'himself' is similar to that of satisfaction in 'life as a whole'. But the ratio of satisfaction for 'our society' is less than 10%. (6) The middle school students in Pusan city respect 'The great King SaeJong' (14.3%), 'Lee soon-shin' (11.1%), 'parents' (10.3%) in Korea. They respect 'Edison' (14.3%), 'Lincoln' (10.3%), 'Einstein' (9.3%) in the world. There is a difference between boy students and girl students in their figures. Students tend to come to know these figures through their text books. Therefore, we can see that the school education has a direct influence upon their way of thinking. (7) The middle students' job preference appears as follows : 'teacher (17.3%), 'designer' (7.5%), 'doctor' (6.8%), 'engineer' (6.7%), 'public entertainer' (5.2%) and so on. The Middle school students have tendency to prefer professional job, but there is difference between boy students and girl students. While boy students prefer to be engineers, scientists, teachers, and athletes, girl students prefer to be teachers, designers, doctors and public entertainers. (8) The middle school students in Pusan city think that 'self-satisfaction' (57.0%) is more important than 'money' (23.8%) or 'power' (4.4%) in the course of life. And, for success in life, they think that 'self-endeavor' is more important than 'home background' or 'human relation' and 'unexpected fortune' is not very good. From this viewpoint, they are less affected by 'materialism' or 'connectionism'. (9) As for the middle school students in Pusan city, scholasticachievements correlate with the socio-economic background. The subjective estimation about scholastic achievements shows a meaningful difference according to 'self-estimation about a living standard' and 'father's job category'. Namely, the students who answered that their family is rich are good at their achievements. And in order of 'new middle strata'> 'upper working class' > 'old middle strata' > 'productive working class', students answered that they are good at their achievements. Objective 'ranking in the classroom' shows a meaningful difference according to 'self-estimation about living standard', 'total income' and 'father's job category'. That is, the students who answered that their family is rich get high ranking in the classroom, and the more total income their family has, the higher their ranking is. As for the father's job category, the order is as follows : 'upper working class' > 'new middle strata' > 'old middle strata' > 'productive working class'. (10) The objective socio-economic indicator such as 'total income' or 'father's job category' do not correlate with 'the degree of satisfaction at life'. But 'the degree of satisfaction at life' correlates with 'self-estimation about living standard'. Because this survey was carried out only for the second grade of middle school students in Pusan city within a limited range, there is some limitations in generalizing these results. Notwithstanding, these results show us some clues to understanding how middle school students in Pusan city live and what they think I expect that these results will be used as a useful empirical data about middle school students.

높은 지향성을 갖는 Air Line 결합기 설계

길준범,이성원,최영호,박종임,안달,박준석 호서대학교 반도체제조장비국산화연구센터 2000 학술대회 자료집 Vol.2000 No.1

본 논문에서는, 일반적인 스트립 구조의 결합기가 갖는 문제 즉, 높은 온도에서 나쁜 특성을 보이는 문제점을 극복하고자 Air Line Type의 결합기를 구현하였다. 또한 이 결합기는 24dB이상의 지향성을 가지고 있다. 해석을 위해 짝수 모드와 홀수 모드 해석법을 사용하였고, EM-Simulation으로 확인한 특성과 실제 제작된 20dB, 30dB Cellular 대역(800∼900MHz) Air Line 결합기의 결고 특성은 좋은 일치를 보여주고 있다. 또한 최대 장점인 온도 특성은 온도 데이터를 통하여 온도에 강한 특성을 보임을 알 수 있다.