20년, 무거운 리듬을 타고 흐르다

민재기(閔宰基) 새얼문화재단 2013 황해문화 Vol.81 No.-

Stabilization of Low Symmetry Morphology in Block Copolymer Electrolytes

민재민,박문정 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2

We investigated phase behavior of acid-tethered block copolymers containing nonstoichiometric ionic liquids to underpin a role of long-range interactions in determining morphologies of block copolymer electrolytes. Radical phase shifts between A15 and lamellar structures were observed for sulfonic acid-tethered block copolymers comprising the ionic liquids. The molar ratio of cationic and anionic moieties was a key to cause the unique phase transitions, where the excess amount of cations in ionic domains stabilized the low symmetry morphology. It is in contrary to the common wisdom established for uncharged block copolymers. Molecular dynamics simulations suggested that the formation of thin ionic shell layers at the micellar core-corona interfaces played a crucial role in stabilizing the A15 structures for block copolymer electrolytes. The development of A15 phases was connected to the enhanced ionic conductivities, suggesting a new avenue for developing advanced polymer electrolytes.

신생대 마이오세 연일충군의 흥해층 및 두호층에서 발견된 고래 화석 예비연구

민재웅,허민 대한지질학회 2009 대한지질학회 학술대회 Vol.2009 No.

CEO 교체 형태가 고유변동성과 기업 투자 및 재무 정책에 미치는 영향에 대한 연구

민재훈(Jae Hoon Min) 대한경영학회 2015 大韓經營學會誌 Vol.28 No.10

본 연구는 CEO 교체 기간 동안의 주식 수익률의 고유변동성(idiosyncratic risk)을 향후 기업 전략과 신임 최고 경영자의 능력에 대한 외부투자자의 불확실성을 대리하는 변수로 삼고, CEO 교체의 원인과 신임 CEO의 출신 등 CEO 교체와 관련된 형태에 따라서 고유변동성이 CEO 변경 공시에 다르게 반응하는 가에 대해서 조사해 보았다. 또한 CEO 공시 전 · 후 기간의 고유변동성이 최고 경영자의 위험회피성향을 반영한다고 가정하고, 특이 변동성의 변화에 따라서 CEO 교체 이후의 기업의 투자 및 재무 정책에 미치는 영향에 대해서 조사해 보았다. CEO의 교체 유형에 따라서 CEO 공시를 전 · 후로 고유변동성은 차별적인 움직임을 보였다. 고유변동성은 CEO의 변경이 자발적으로 이루어진 경우보다 비자발적으로 이루어졌을 때 높게 나타났다. 또한 CEO가 교체될 때 대주주가 이사회 임원으로 직접 경영에 참여하는 경우가 그렇지 않은 경우에 비해서 고유변동성의 변화가 작게 나타났다. CEO 교체 공시를 전 · 후로 한 1년 동안 고유변동성은 대주주가 경영에 참여하지 않는 전문경영인 기업에서 전임 CEO가 비자발적으로 물러나고 외부인사에 의한 신임 CEO의 영입이 이루어진 경우가 대주주가 이사로 직접 경영에 참여하는 소유경영기업에서 자발적인 CEO의 퇴임과 내부인사에 의한 승계가 이루어진 경우에 비해 약 12% p나 높은 것으로 나타났다. 이와 같은 결과는 외부투자자가 새로운 CEO의 기업 정책과 능력에 대한 예측이 어려울수록 리더십에 대한 불확실성이 높고 이에 따라서 고유변동성이 높게 나타난다는 가설을 입증한다. 또한 대주주의 경영 참여와 조정 능력이 리더십의 교체에 따른 외부투자자의 불안감을 완화시키는 데 기여하는 것으로 입증되었다. 한편 고유변동성의 증가가 최고 경영자의 위험회피성향을 높여서 향후 R&D나 비유동자산 투자와 같은 위험 투자 규모를 축소시키고 현금성 자산 등의 보유를 늘리는 등 재무적 안정성을 추구할 것이라는 경영자 위험 회피 가설은 실증 분석결과 지지되지 않았다. 오히려 신임 CEO는 고유변동성이 증가할 때 현금성 자산을 줄이는 동시에 R&D나 고정자산투자를 늘리는 등 과감한 투자를 단행하였으며, 특히 경영 성과가 저조한 기업의 경영자의 경우 현상황을 타개하기 위해서 더욱 공격적인 경영을 하는 것으로 나타났다. The purpose of this study is to examine any differential impact of CEO turnover according to the types of CEO changes. This study hypothesizes that idiosyncratic risk of stock return at the time of CEO turnover can reflect outside investors’ anxiety about leadership uncertainty with respect to corporate strategy change and new CEO’s ability. In this regard, this study predicts that idiosyncratic risk rises relatively higher surrounding CEO turnover when a new CEO from outside of the firm replaces the incumbent CEO who is forced to leave a company compared to the case that a new CEO from inside of the firm succeeds to a former CEO who steps down voluntarily. In addition, this study hypothesizes that presence of major shareholders including founder’s family in the board of directors can mitigate investor’s anxiety about leadership uncertainty around CEO changes. Each individual CEO turnover is classified into three types: i) whether CEO turnover is voluntary or forced, ii) whether newly appointed CEO is from inside or outside the firm, and iii) whether major shareholder participates in firm management as a member of the board of directors at the time of CEO turnover. Results from an univariate analysis suggest that the type of CEO turnover has a differential impact on idiosyncratic risk surrounding the announcement of CEO changes. First, idiosyncratic volatility is greater about 6% p per annum in case of involuntary resignation compared to voluntary resignation or additional appointment of CEO without resignation surrounding CEO turnover. Investors seem to have both expectation and anxiety about the future course of action new CEO will take to improve the firm performance when a new CEO replaces retiring CEO who is forced to step down. Second, new CEO’s background is also associated with the size of idiosyncratic volatility. When a new CEO comes from inside of the firm, the idiosyncratic volatility is about 7% p per annum lower than when he comes from outside of the firm. This fact supports the CEO ability hypothesis in that investors worry about the new CEO’s leadership since he has no track record about his ability in the firm. Third, presence of major shareholders in the board of directors plays an effective role of reducing investors’ anxiety over the leadership change. When major shareholders including founder’s family members participate actively in firm management, idiosyncratic volatility is about 6% p per annum lower than the case where major shareholders do not involve in firm management as B.O.D. members. Overall, idiosyncratic risk is 12% p per annum greater when CEO turnover is involuntary, and when new CEO comes from outside of the firm, and when major shareholder does not participate directly in firm management, than when CEO turnover is voluntary, and when insider succession is made, and when major shareholder involves in firm management as a director. These results support the strategy and ability hypotheses that predict a higher idiosyncratic volatility when investors have difficulty to forecast a new CEO’s future business policy and capability. This study also attempts to investigate whether a new CEO who is hypothesized to be a risky averter tries to reduce risky investments such as R&D expenses and capital expenditures and to increase cash holdings in an effort to restore organizational stability after CEO changes, and whether the type of CEO turnover is associated with a new CEO’s investment and financial decision. In conclusion, a rise in idiosyncratic volatility surrounding CEO changes does not seem to raise a new CEO’s risk aversion. Rather, R&D expenditures and investment in fixed asset tend to increase whereas corporate cash holdings tend to decrease following CEO turnover. Especially in the firms where their profitability is low, new CEOs seem to try to invest more aggressively in R&D and fixed assets to overcome the current poor business situation. The type of CEO turnover also seems to m

폐탄광지의 산림복원을 위한 식생구조 분석

민재기,조민기,김종갑,문현식 한국임학회 2008 한국임학회 정기학술발표논문집 Vol.2008 No.-

BERT를 이용한 한국어 특허상담 기계독해

민재옥,박진우,조유정,이봉건,Min, Jae-Ok,Park, Jin-Woo,Jo, Yu-Jeong,Lee, Bong-Gun 한국정보처리학회 2020 정보처리학회논문지. 소프트웨어 및 데이터 공학 Vol.9 No.4

기계독해는(Machine reading comprehension) 사용자 질의와 관련된 문서를 기계가 이해한 후 정답을 추론하는 인공지능 자연어처리 태스크를 말하며, 이러한 기계독해는 챗봇과 같은 자동상담 서비스에 활용될 수 있다. 최근 자연어처리 분야에서 가장 높은 성능을 보이고 있는 BERT 언어모델은 대용량의 데이터를 pre-training 한 후에 각 자연어처리 태스크에 대해 fine-tuning하여 학습된 모델로 추론함으로써 문제를 해결하는 방식이다. 본 논문에서는 BERT기반 특허상담 기계독해 태스크를 위해 특허상담 데이터 셋을 구축하고 그 구축 방법을 소개하며, patent 코퍼스를 pre-training한 Patent-BERT 모델과 특허상담 모델학습에 적합한 언어처리 알고리즘을 추가함으로써 특허상담 기계독해 태스크의 성능을 향상시킬 수 있는 방안을 제안한다. 본 논문에서 제안한 방법을 사용하여 특허상담 질의에 대한 정답 결정에서 성능이 향상됨을 보였다. MRC (Machine reading comprehension) is the AI NLP task that predict the answer for user's query by understanding of the relevant document and which can be used in automated consult services such as chatbots. Recently, the BERT (Pre-training of Deep Bidirectional Transformers for Language Understanding) model, which shows high performance in various fields of natural language processing, have two phases. First phase is Pre-training the big data of each domain. And second phase is fine-tuning the model for solving each NLP tasks as a prediction. In this paper, we have made the Patent MRC dataset and shown that how to build the patent consultation training data for MRC task. And we propose the method to improve the performance of the MRC task using the Pre-trained Patent-BERT model by the patent consultation corpus and the language processing algorithm suitable for the machine learning of the patent counseling data. As a result of experiment, we show that the performance of the method proposed in this paper is improved to answer the patent counseling query.

한국어 관계절에 관한 연구

閔在基 건국대학교 인문과학연구소 1991 인문과학논총 Vol.23 No.-

There has been heated arguments as to the relative clause in Korea language. This paper aims to explore a better solution possible on the theme. Relative clause, a kind of relative constitutions, usually functions as a modifier of nouns. Morphologically speaking, a relative word is defined as the verbs and adjectives when exclusively modify nouns. The term "clause" in this paper is confined to indicate both functional and theoretical significances. This implies that we are going to grasp sentences mainly focusing on the predicates. All clauses introduced by the endings of relative-forms are classified into relative clauses, which implies that every constitution combined formative nouns and relative clauses must be analyzed in this connection. However, it is difficult to determine the definition of such analysis. As relative clause modifies nouns, it is the constituent element of noun phrase. Lim Hong-Bin(1987b:391) classifies the noun phrases of Korean language into two: pre-title element and post-title element. Our main concern in this paper is on the pre-title element and the inner constitution of noun phrase. This, however, is contrary to the method of Chomsky(1986) in his X-bar frame. Chomsky(1986 : 2~3) has a view dealing sentence as an endocentric constitution. I think his frame is too simple to clarify our problem. So, I am not going to adopt this frame in this paper. In the classification of relative clauses, in Korea language, complement sentences are also taken into consideration. If details are ignored, relative clauses and complement sentences in Korean language are almost similar to those of English. However, delicate fifferences between them are also mentioned and explored as far as possible. There are some cases hard to be called clause, which I classified into "quasi-relative clause" on my own term. At the last portion of the paper, some discussion are given pertaining to normal relative clauses. In this connection, I proposed three possible structures of relative clauses with due explanation thereof. Lastly, some mentions are given about the functions of phrases. Anyhow, further research and explorations are yet required in this field of study.

창간 2주년 기념사

민재기,Min, Jae-Gi 대한인쇄문화협회 2004 프린팅코리아 Vol.25 No.-

A Fluorescent Optode Membrane for pH Sensing under Extremely Acidic Condition

민재영,김형진 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

We synthesized a donor-acceptor conjugated dye (6) possessing an acryloyl group and prepared a pH-sensitive optode membrane via the photo-copolymerization of 6 with a mixture of HEMA and triethylene glycol dimethacrylate on a silanized glass surface. The optode membrane exhibited two absorption bands at approximately 370 and 450 nm, and a strong fluorescence at approximately 630 nm after excitation at 450 nm. The optode membrane displayed a ratiometric absorption response to pH changes. As the pH increased from 0.0 to 2.0, the absorbance ratio of the membrane increased. The fluorescence of the membrane increased with increasing pH from 0.0 to 2.0 and showed a good linear response to pH changes in this range. The membrane operation was reversible, reproducible, and stable for repeated measurements under acidic conditions. The membrane showed an operable response time and good tolerance for high salt concentrations.

도심항공교통(UAM) 운용을 위한 버티포트(Vertiport) 구축에 관한 연구

민재선(Jae Seon Min),강병엽(Byungyup Kang),이영재(Youngjae Lee),정봉철(Bong Cheul Chung),이재우(Jae-Woo Lee) 한국항공우주학회 2020 한국항공우주학회 학술발표회 논문집 Vol.2020 No.11