저감속 회수장비 시험조건에 따른 초음속 시험탄 감속특성에 대한 수치해석적 연구

송민섭,김재훈,Song, Minsup,Kim, Jaehoon 한국군사과학기술학회 2020 한국군사과학기술학회지 Vol.23 No.5

Numerical analyses were performed using a one-dimensional Euler equation and Godunov Harten-Lax-Van Leer(HLL) Riemann solver in order to study the deceleration characteristics of a 155 mm projectile in a soft recovery system. The soft recovery system consisting of a series of pressure tubes is a system that decelerates the test projectile fired at supersonic speed using a high-pressure gas and filled water inside. Therefore, depending on the gas pressure and the amount of water filling, the deceleration and the exit velocity of the test projectile inside the pressure tube are determined. In this paper, the deceleration characteristics of the test projectile were analyzed according to the gas pressure and water mass filled.

철도 차량용 APS 병렬 운전 알고리즘 연구

송민섭(Min-Sup Song),김연충(Yuen Chung Kim) 한국철도학회 2016 한국철도학회 학술발표대회논문집 Vol.2016 No.5

철도 차량용 보조전원장치 (APS, Auxiliary Power Supply)는 차량에 필요한 전원을 공급하는 핵심적인 전장품으로써 차량 편성에 따라 2대 이상으로 구성되어 독립적으로 운영된다. 일부 APS에 고장 발생 시 정상 운영 중인 APS가 연장 급전을 통해서 고장이 발생한 APS의 부하에 임시적으로 전원을 공급할 때 까지 전원이 일시적으로 차단되어 승객에 불편을 초래한다. 본 논문에서는 이러한 문제점을 해결하기 위해서 2대 이상의 APS가 상시 병렬 운전을 하여 끊김없는 전원 공급을 할 수 있는 APS 병렬 운전 알고리즘에 대해서 연구하였다. 병렬 운전을 위한 통신 및 외부 제어 부담을 최소화 하기 위해 간단하고 효과적인 제어 알고리즘을 제안하고, PSIM 시뮬레이션으로 타당성을 검증하였다. Auxiliary power supply (APS) for railway vehicle, consisting of more than two subs, is the key electric component for supplying electric power of vehicle. When one of APS fails, fault one is stopped and disunited from vehicle load. During the extension of power from remaining normal APS, passengers have to endure inconvenience due to temporarily blocked electric power. In this paper, the simple parallel synchronous operation algorithm for APS was propose, with which All APS can operated in parallel at all times resulting seamless power supply to load even during failure of some APS. For minimizing the communication and other external control efforts to implement synchronous operation, simple but effective control algorithm was suggested and verified by PSIM simulation.

2008년 금융위기와 애널리스트의 예측 성향의 변화

송민섭(Min Sup Song),변상혁(Sang Hyuk Byun) 한국경영학회 2013 經營學硏究 Vol.42 No.5

Press indicates that optimistic bias in information intermediaries such as analysts is one of the major causes for 2008 financial crisis. The objective of this study is to examine whether and how analysts change their forecasting behaviors around 2008 financial crisis to investigate the role of analysts in capital market during 2008 financial crisis. More specifically, we examine how analysts revise their stock recommendations and earnings forecasts around 2008 financial crisis. We also examine the change in investors` reactions to analysts` earnings forecast revisions around 2008 financial crisis. Empirical results show that analysts tend to simply reiterate their existing forecasts or do not issue forecasts during 2008 financial crisis. Relatively small number of analysts revised their stock recommendations and earnings forecasts during financial crisis. Because of these behaviors,overall analyst forecasts and recommendations become optimistically biased. In addition, we find insignificant earnings response coefficient on analysts` upward earnings revisions during financial crisis period, while we find stronger market reaction to downward revisions. Our empirical results suggest that analysts play the limited role as information intermediaries during 2008 financial crisis. In addition, investors tend to discount information content of analyst forecasts if forecasts are inconsistent with stock market condition. Our evidence helps investors and regulators and investors in assessing value of analyst forecasts and need for new regulation.

바텀애시를 사용한 모르터의 특성에 대한 실험적 연구

송민섭 ( Min Seob Song ),김영덕 ( Young Duck Kim ),나철성 ( Chul Sung Na ),최경렬 ( Kyung Ryul Choi ),김재환 ( Jae Hwan Kim ),김무한 ( Moo Han Kim ) 한국건축시공학회 2003 한국건축시공학회 학술발표대회 논문집 Vol.3 No.1

Bottom ash among the coal ash is not used because of its poor properties. But encouraging the use of bottom ash as a construction material is a sensible method of utilization as it avoids the problems and costs associated with disposal and provides an alternative aggregate source. This study was aimed at using bottom ash as an alternative fine aggregate source to provide a solution to disposal and insufficient fine aggregate for the production of concrete. So properties of domestic bottom ash were estimated due to the difference of each domestic bottom ash. And compressive strength and durability were estimated as basic data to use bottom ash in building industries. As a result of the experiment, the very porous surface and angular shape of the bottom ash particles necessitate a higher apparent water-cement ratio. And due to the higher water requirement, the compressive strength and durability of mortar is lower than those of the control samples. But when 25 percent of the total dry weight of the natural fine aggregate was replaced by bottom ash, the engineering characteristics were similar.

인공신경망을 이용한 강도추정 시스템의 검증에 관한 실험적 연구

송민섭(Song, Min Seob),박종호(Park, Jong Ho),김갑수(Kim, Kab Soo),장종호(Jang, Jong Ho),임재홍(Lim, Jae Hong),김무한(Kim, Moo Han) 한국콘크리트학회 2004 한국콘크리트학회 학술대회 논문집 Vol.2004 No.5

기업의 분기이익보고가 애널리스트의 이익 예측치에 미치는 영향에 관한 연구

송민섭(Min Sup Song) 한국경영학회 2008 經營學硏究 Vol.37 No.6

This paper examines the effect of quarterly earnings announcements on analysts` forecast revisions and their accuracy. In 2000, new regulation of the financial markets in Korea began requiring firms to disclosure quarterly accounting reports. If quarterly earnings announcements provide additional information and analysts use those information to form their new forecast, there should be difference in forecast properties around earnings announcements. Empirical results show a significant increase in the number of analyst forecast revisions following the earnings announcements. Results also show that forecasts issued immediately after the earnings announcement are revised by large magnitude and are more accurate. However, revisions issued relatively long after earnings announcements have indifferent forecast accuracy from forecast revisions immediately after the announcements. These results suggest that quarterly announcements provide predictive information about future earnings, and new information contained in earnings announcements are more likely reflected by those forecast issued immediately after earnings announcements.

고전압 이용을 위한 다중인접 기준벡터 불연속변조기법 기반의 다이오드 클램핑 멀티레벨 LLC 공진형 컨버터

송민섭(Min-Sup Song),조인호(In-Ho Cho),이재범(Jae-Bum Lee),류준형(Joon-Hyoung Ryu) 한국철도학회 2021 한국철도학회논문집 Vol.24 No.3

기업공개를 위한 벤처중소기업의 경영구조사례 연구

송민섭 ( Min Sub Song ) 한국인터넷비즈니스학회 2004 인터넷비지니스연구 Vol.5 No.2

증예(症例) : 항결핵제 투여후 발생한 전격성 간염 1예

송민섭 ( Min Seop Song ),황민호 ( Min Ho Hwang ),윤찬호 ( Chan Ho Yun ),김용문 ( Yong Mun Kim ),김정화 ( Jeoung Hwa Kim ),조덕수 ( Deok Su Cho ),김귀완 ( Kwi Wan Kim ) 전북대학교 의과학연구소 2001 全北醫大論文集 Vol.25 No.1

항결핵제는 황달을 포함한 전격성 간염에 이르기까지 다양한 정도의 간기능 이상을 초래할 수 있는데 INH, PZA에서 비교적 흔하고 INH와 RFP을 동시에 투여할 때 간독성의 상승효과가 있다. 저자등은 바이러스성 및 자가면역성 간질환이 배제되었고, 다른 독성 물질에 노출된 적이 없었던 4제 병용 투여환자에서 발생한 전격성 간염 1 예를 경험하였기에 문헌고찰과 함께 이를 보고하는 바이다. Idiosyncratic drug reactions may cause fulminant hepatic failure. The most frequent culprits are anaesthetic agents, non-steroidal anti-inflammatory drugs and isoniazid given with rifampicin. In approximately 10 percent of adults treated with the antituberculous drug isoniazid, elevated serum aminotransferase levels develop during the first few weeks of therapy. We report a twenty six year-old male patient with fulminant hepatitis due to antituberculous drugs (isoniazid, rifampicin, ethambutol, pyrazinamide), He, previously having been well, typically develops non-specific symptoms-nausea, malaise and showed jaundice. He suffered from uncontrolled ascites and pleural effusion. Viral hepatitis and alcoholic hepatitis were excluded from his history and serological study data. After changing of antituberculous drugs and with conservative care, he was discharged with improved clinical condition.

연구논문 : 자본시장 제약과 현금의 가치관련성에 관한 연구: 2008년 금융위기를 중심으로

송민섭 ( Min Sup Song ) 한국회계학회 2014 회계저널 Vol.23 No.1

본 연구는 2008년 금융위기 전후로 기업 보유현금의 가치관련성이 현금흐름의 원천별로 차이가 존재하는 지 분석하는 것을 목적으로 한다. 2008년 금융위기는 주식시장과 채권시장을 동시에 경색시켜 기업이 외부자본시장에서 자본조달을 어렵게 만들고, 이러한 환경 변화는 기업이 내부적으로 보유하는 현금의 가치를 상대적으로 증가시킬 것으로 예상된다. 특히, 금융위기로 인한 전체 실물 경제의 침체는 현금의 수익성 및 지속성 이외에 유동성 및 자금 안정성과 같은 특성의 상대적 가치를 증가시켜 현금 원천별로 가치관련성의 차이가 존재할 것으로 예상된다. 실증분석 결과, 금융위기 시기에 순 현금흐름의 가치관련성은 더욱 증가하였으며, 이익과 배당의 가치관련성은 상대적으로 감소하였다. 특히, 재무활동으로부터 발생하는 현금흐름의 가치관련성이 금융위기 시기에 영업 및 투자현금흐름에 비해 상대적으로 증가하였다. 이러한 결과는 투자자들이 금융위기로 인하여 자본시장의 제약이 증가할수록 기업이 자체적으로 창출하는 현금에 대해 가치를 더욱 부여하고 있었으며, 특히 기업의 유동성 및 자금 안정성과 같은 특성에 대하여 상대적으로 가치를 높게 부여하고 있다는 것을 의미한다. This study empirically investigates whether and how 2008 financial crisis affects value relevance of cash holdings. More specifically, this study examines whether changes in value relevance of cash flows during the financial crisis period differs across the sources of cash flows from operating, investing, and financing activities. The increased financial constraints due to collapse of debt and equity market during financial crisis will increase the relative importance of a firm`s internal cash holdings. Especially, since the crisis affects the whole economy as well as financial industry, the properties of cash flows such as liquidity and solvency will become more important to investors. Empirical results show that the value relevance of net cash flows has increased during financial crisis. In addition, value relevance of cash flows from financing activities has increased significantly during financial crisis, while cash flows from operating and investing activities do not. These results suggest that investors value liquidity or solvency that is closed related to properties of cash flows from financing activities during financial crisis than other period.