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.

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

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

[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.

두경부에 발생한 방선균증 3예

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

말레이 무슬림 정체성의 역동적 성격 : 말레이시아 끌란딴(Kelantan)과 태국 빠따니(Patani)의 말레이 사회에 대한 비교연구 The Comparative Study of Malay Societies in Malaysia and Thailand

홍석준 한국동남아학회 2003 동남아시아연구 Vol.13 No.1

This paper deals with ethnicity and ethnic identity in Malaysia and southern Thailand at the intra-Malay level. It was once supposed that ethnicity became a more important aspect of people's identity with culture contact. Ethnicity was associated with tradition and conservatism in the organization of social relations, and urbanization with modernity and change. Continued research of the matter has indicated otherwise, however. In the ethnically diverse and competitive environment of the modern cultural situation, ethnic awareness tends to be heightened, and ethnicity is likely to become not less but more relevant as a basis for people's relating to one another. This paper examines the historical, early ethnographic, and contemporary political analyses of the dynamics of the Malay-Muslims identities of Malaysia, especially Kelantan(the northeastern area of Malay peninsula) state, and Thailand, especially Patani region where located in the southern area of Thailand. The historical and ethnographic overview descries the Islamic influence on the traditional kingdom of Patani and Kelantanese Malays, the consequences of British colonialism, and the results of the reign of Thailand kingdom. The contemporary plolitical analysis is deprived from scholarly attempts at assessing the recent situation of Malay-Muslims as they faced the internal colonialism of the Thailand government and experience ethnic repression in malaysia and Thailand. The central concern in this paper is that under what conditions is ethnic identity activated and used as the basis for political mobilization more actively and effectively. In other words, what accounts for variation in the level of ethnic nationalism between the two Malay-Muslims communities? In this paper, it is hypothesized that certain aspects of ethnic policy produce the conditions under which ethnicity becomes most effectively utilized by the group as the basis for political mobilization. Consequently, this paper proposes to examine the relationship between the religious and ethnic policy and political mobilization, and degree of involvement in religious or ethnic activities of the Malay-Muslims communities in Malaysia and southern Thailand. The dynamics of ethnicity in Malaysia and Thailand show that the Malay-Muslims'ideas and attitudes of their own traditions have strict oppositions or a lot of differentiations in terms of the differences of religious understandings of Islamic principles and values, which have been influenced by the implementation of Islamization policy. In conclusion, this paper has illustrated the fluidity of malay-Muslims identities in Malaysia and Thailand, and has stressed that these identities are continually constructed and reconstructed on the basis of situationally defined political and social interests. They are not just primordial, nor are they purely voluntary constructions. They interact with outside forces, definitions as well and are important resources for political organizing. A remaining issue is whether these identities facilitate connections or set up barriers.

일차 양측성 구순열의 일단계 재건에 대한 증례보고

임석균,이기혁,김영균,김수관,이병준,여환호,서재훈 大韓顎顔面成形再建外科學會 1996 Maxillofacial Plastic Reconstructive Surgery Vol.18 No.3

Bilateral cleft lip reconstruction can be performed in one-or two-stages. The choice depends on the surgeon's proficiency and experience. However the type and severity of the cleft must be considered. Complete or incomplete symmetric, bilateral clefts in which the premaxilla is within the alveolar arch or slightly protruded can be successfully treated with simultaneous lip reconstruction on both sides. There are some advantages that one-stage lip reconstruction facilitates creation of a symmetric and balanced lip, retraction of protruding premaxilla and the parent's psychologic satisfaction. However, there are some disadvantages such as micrognathia of the upper jaw by severe scar formation and poor adaptation of flap margins by severe tension. The surgeon must be able to judge and exploit the advantages offered by one-stage approach. We present the case report of one-stage reconstruction of primary bilateral cleft lip with literature reviews.

자동차용 강판의 점용접성에 관한 연구

배석천,민준기 啓明大學校 産業技術硏究所 1997 産業技術硏究所 論文報告集 Vol.20 No.-

The resistance spot welding is widely used for automotive assembling, electric manufacture and airplane industry. Parametric studies, welding current, welding time, and electrode forec, has been madeto to investigate spot weldability, microstructure of welding zone, TSS and CTS of SPC, HPC, SPC Zn and SPC Zn-Fe. Some of important results derived in this study are followed : - In spot welding, weldability is moved into the lower welding current area as the tensile strength of sheet metal increases, and for the optimum welding condition the electroplated steel sheet requires higher current comparing with uncoated steel plate. - The electrode force and welding time obviously affects the TSS, CTS, but the critical range of representing ultimate welding strength is observed - Indentation formed by over welding current causes a decrease in the welding strength. - CTS and ductility ratio of HPC are increased by the tempering treatment. The improvement of these mechanical properties is marked for the higher strengthened base metal among HPC.