카본블랙과 실리카의 혼합사용 〔 1 〕

정연채 한국고무학회 1985 엘라스토머 및 콤포지트 Vol.20 No.3

본태성 고혈압에서 Doxazocin(Cardura(r))의 강압효과에 대한 임상적 관찰

정연채,구대회,김백수,최용석,성인환,전은석,박종훈 대한순환기학회 1990 Korean Circulation Journal Vol.20 No.4

확장성 심근중에서 승모판륜 운동과 승모판 혈류속도의 관찰

정연채,최용석,김백수,구대희,강원권,성인환,전은석,박종훈 대한순환기학회 1990 Korean Circulation Journal Vol.20 No.3

공정제어에 의한 Ti-Al계 복합화합물의 제조에 관한 기초 연구

정연채,이동수,윤대원,이상화 동아대학교 생산기술연구소 2000 生産技術硏究所硏究論文集 Vol.5 No.1

The Ti-Aluminide intermetallic compounds which used in the tumbler and planetary ball mill were fabricated by MA-SPS. The results are as follows. 1. The Planetary ball mill alloying time was shorter than the tumbler and the mainly produced phase after SPS was Ti_3Al phase. 2. The process which added N_2gas during mechanical alloying(MA) decreased mechanical alloying time and increased the yield ratio of alloying powders. 3. The density of sintered body nearly reached the theory density when SPS sintering temperature was over 1050℃ Therefore Ti-Aluminide intermetallic compounds could be produced.

카본블랙과 실리카의 혼합방법 〔 2 〕

정연채 한국고무학회 1985 엘라스토머 및 콤포지트 Vol.20 No.4

Dynamic Positioning 선박들의 사고사례 분석

채종주,정연철 한국항해항만학회 2015 한국항해항만학회지 Vol.39 No.3

Dynamic Positioning System(DPS)은 동력, DP control 장치, DP 컴퓨터, 위치참조시스템(PRS), 센서, thruster 시스템 및 DP 운용 자(DPO) 7가지로 구성되어 있다. DP 선박은 이들 구성요소들에 문제가 발생하면 그 기능을 상실할 수 있는데 이러한 DP 선박의 위치손실사 고(Loss of Position, LOP)는 선주가 자발적으로 매년 IMCA에 보고하고 있다. 본 연구에서는 2001∼2010년까지 10년 동안 IMCA 보고된 DP 선박 관련사고 612건에 대한 분석을 바탕으로 DPS의 7가지 구성요소와 관련된 사고 원인을 파악하고 이들 중 높은 비율을 차지하는 요인의 정성적, 정량적 분석을 통한 DP 선박의 안전운항 방안을 모색하고자 한다. 10년 평균 가장 높은 비율을 차지한 DPS 사고원인 요소는 PRS였 다. 이를 전문가들의 브레인스토밍을 통해 작성된 flowchart를 바탕으로 베이지안 네트워크 분석을 시행한 결과 PRS 각 요소별 조건부 확률 을 확인할 수 있었다. DP 선박의 drive off를 발생시키는데 주요한 영향을 미치는 것은 DGPS, microwave radar 및 HPR 이었고 DGPS에 주 요한 영향을 미치는 에러 요인은 signal blocked, electric components failure, relative mode error 및 signal weak or fail이라는 것도 확인할 수 있었다. The Dynamic Positioning System consists of 7 elements which are namely Power system, Human machine interface, DP Computer, Position Reference System(PRS), Sensors, Thruster system and DP Operator. Incidents like loss of position(LOP) on DP vessel usually occur due to errors in these 7 elements. The purpose of this study is to find out safety operation method of DP vessel through qualitative and quantitative analyze of DP LOP incidents which are submitted to IMCA every year. The 612 DP LOP incidents submitted from 2001 to 2010 were analyzed to find out the main cause of the incidents and its rate among other causes. Consequently, the highest rate of incidents involving DP elements are PRS errors. DP computer, Power system, Human error and thruster system came next. The PRS has been analyzed and a flowchart was drawn through expert brainstorming. Also, the conditional probability has been analyzed through Bayesian Networks based on this flowchart. Consequentially, the main causes of drive off incidents were DGPS, microwave radar and HPR. Also, this study identified the main causes of DGPS errors through Bayesian Networks. These causes are signal blocked, electric components failure, relative mode error, signal weak or fail.

實學의 平等思想

鄭然植,蔡政旻 慶北大學校 東洋文化硏究所 1984 東洋文化硏究 Vol.11 No.-

It is obvious that equality is the fundamental idea of democracy with freedom and human dignity. We can find the idea of equality in the Korean Shil-Hak that come into exsistence from retort of ideological metaphisics indulging in academic discussion in the exhausted society of the latter Li-dynasty. At that time, Shil-Hak scholars criticized political, social, economic and cutural systems and presented many new reformationary bills. Most of Shil-Hak scholars asserted that man had to be treated equally, recognizing the importance of individuality and rights of human being. So, they denied traditional social class systems of Li-dynasty and asserted that any one who has capable of taking charge of public affairs could be oppointed to the positions of governmental institutions. Also, they maintained to abolish the slavery, discriminative treatment to illegitimate son and discriminative requirement to enter school by social class. But the idea of equality of Shil-Hak scholars had been restrainted by the social and economic situations as compared with modern sense of equality. And they couldn't define the conception of equality demanding right to the government to correct the social discrimination as modern time. But the conception of equality they insisted is very significant in the history of Korean political thoughts because it was succeeded to modern Enlightened-thoughts in the late Li-ldynasty and to modern idea of human right in Korea.

A Study on FSA Application to PRS for Safe Operation of Dynamic Positioning Vessel

채종주,정연철 한국항해항만학회 2017 한국항해항만학회지 Vol.41 No.5

The Formal Safety Assessment (FSA) is a structured and systematic methodology developed by the IMO, aimed at assessing the risk of vessels and recommending the method to control intolerable risks, thereby enhancing maritime safety, including protection of life, health, the marine environment and property, by using risk analysis and cost-benefit assessment. While the FSA has mostly been applied to merchant vessels, it has rarely been applied to a DP vessel, which is one of the special purpose vessels in the offshore industry. Furthermore, most of the FSA has been conducted so far by using the Fault Tree Analysis tool, even though there are many other risk analysis tools. This study carried out the FSA for safe operation of DP vessels by using the Bayesian network, under which conditional probability was examined. This study determined the frequency and severity of DP LOP incidents reported to the IMCA from 2001 to 2010, and obtained the Risk Index by applying the Bayesian network. Then, the Risk Control Options (RCOs) were identified through an expert brainstorming and DP vessel simulations. This study recommends duplication of PRS, regardless of the DP class and PRS type and DP system specific training. Finally, this study verified that the Bayesian network and DP simulator can also serve as an effective tool for FSA implementation.

開化思想의 民主主義的 要素

鄭然植,蔡政旻 경북대학교 사회과학대학 1983 社會科學 Vol.2 No.-

The Korean enlightenment is the modern thought which come into being under the influences of Shi-hak (Practical Science), Chinese civilzed thought, Japanese Mei-Ji Renovation and direct making an observation to the United States and throughout the most of modern European countries in the late 19th centry. We can find out not a few democratic elements in those thoughts. The enlightened reformists proclaimed the rights of equality and freedom which are fundamental and inalienable human rights, given by heaven-freedom of life, body, speech, meeting, association and religion. Also, they asserted the constitutionalism, not rule of arbitrariness of king or nobility but rule of Law. At the same time they requested to establish a National Assembly, unprecedent matter in the Korean political history. Practically, they published th paper-The Independent (Dok-lip Shin-mun), organized the Independence club (Doklip Hyup-hoi) and sponsored the meeting consisted of all classes and government officials (Guan-min Gong-dong-hoi). Through such process, they inspired the people with the consciousness of political participation and asserted to reform the political structure from traditional to modern gradually. Even if reformists could not reach to the idea of popular soveregnity and maintained limitting constitutional monarchism, it is very important meaning that the enlightenment involved modern and democratic thought in the Korea for the first time. That enlightenment had influenced on the 1919 Independent Movement, moreover on establishing new Korean democratic government.

디지털 이미지를 이용한 심층 신경망 기반 흙의 함수비 및 건조밀도 예측

김동근 ( Donggeun Kim ),김태진 ( Taejin Kim ),전지훈 ( Jihun Jeon ),손영환 ( Younghwan Son ) 한국농공학회 2020 한국농공학회 학술대회초록집 Vol.2020 No.-

딥러닝 (Deep Learning)은 이미지 분류 및 분석 분야에서 기존의 분석 알고리즘들과 비교하여 매우 높은 성능을 갖는 것으로 알려져 있다. 이에 따라 디지털 이미지를 이용한 토양 특성 예측 분야에 딥러닝을 적용하면 낮은 비용으로 신속하게 현장의 토양 관리를 수행할 수 있을 것으로 기대된다. 본 연구에서는 딥러닝 기법 중 심층신경망 (Deep Neural Network)을 기반으로 흙의 디지털 이미지를 분석하여 물리적 특성 중 함수비와 건조밀도를 예측하고자 한다. 함수비와 건조밀도를 다르게 조정한 시료를 원형 몰드에 고르게 성형하였으며, 광조건이 일정한 실내 스튜디오에서 표층의 디지털 이미지를 획득하였다. 이때 심층신경망의 입력자료 구축을 위한 이미지 처리 방법으로 디지털 이미지 프로세싱(Digital Image Processing)을 적용하였다. 토양 이미지에서 토양의 색상정보 (RGB)와 함께 임계값 (threshold)별로 간극면적을 추출하였으며 이를 심층신경망의 입력자료로 활용하였다. 임계값별로 추출한 간극면적은 하나의 변수인 표준편차로 치환하여 모델에 입력하였다. 심층신경망의 학습시에는 모델의 신뢰도를 높일 수 있도록 k-겹 교차검증 (k-fold cross validation)을 수행하였다. 심층신경망을 이용한 함수비 예측 시의 RMSE는 0.2∼1.0%로 나타났으며, 건조밀도 예측 시의 RMSE는 0.061∼0.101 t/m³으로 나타나 기존의 연구 결과에 비해 높은 정확도로 토양 특성을 예측할 수 있는 것으로 나타났다. 본 연구의 결과는 향후 신속하고 경제적인 토양 모니터링에 기여할 수 있을 것으로 판단된다.