Facial Exposure Dose Assessment During Intraoral Radiography by Radiological Technologists

유환,양한준 대한방사선과학회 2014 방사선기술과학 Vol.37 No.3

The study examined the changes in the decreased facial exposure dose for radiological technologists depending on increased distance between the workers and the X-ray tube head during intraoral radiography. First, the facial phantom similar to the human tissues was manufactured. The shooting examination was configured to the maxillary molars for adults (60kVp, 10mA, 50msec) and for children (60kVp, 10mA, 20msec), and the chamber was fixed where the facial part of the radiation worker would be placed using the intraoral radiography equipment. The distances between the X-ray tube head and the phantom were set to 10cm, 15cm, 20cm, 25cm, 30cm, 35cm, and 40cm. The phantom was radiated 20 times with each examination condition and the average scattered doses were examined. The rate at the distance of 40cm decreased by about 92.6% to 7.43% based on the scattered rays radiated at the distance of 10cm under the adult conditions. The rate at the distance of 40cm decreased by about 97.6% to 2.58% based on the scattered rays radiated at the distance of 10cm under the children conditions. Protection from the radiation exposure was required during the dental radiographic examination.

중국 장시성 누오(儺) 가면의 특성을 활용한 3D 디지털 패션디자인

유환,이연희 복식문화학회 2022 服飾文化硏究 Vol.30 No.3

The aim of this study was to develop Jiangxi Nuo masks using 3D digital fashion design technology and suggest various ways to utilize traditional culture based on the characteristics of Nuo masks, a traditional Chinese artifact of intangible cultural significance. The researchers conducted a literature review to gather information about Nuo culture and masks that could represent Jiangxi. Features of the masks were analyzed and classified. The result are as follows. First, the symbolic characteristics of Jiangxi’s Nuo masks can be divided into those based on their origin and history, the user’s social status, and the notions of primitive beliefs of the chosen people, such as naturism and totemism. Second, Nuo masks’ splendid decorations convey meanings such as luck, the bixie, longevity, wealth, and peace in the family. Third, playfulness in mask-making is about dismantling the original form of the mask, re-creating it through application. Fourth, the masks express primitiveness mostly by conserving the wood’s original color or material. The initial masks carved to represent images of figures aptly deliver the primitive forms and images of Nuo culture. In this study, Nuo masks were developed and produced using the 3D digital technology CLO 3D by adopting the expressive characteristics and applying design methods such as asymmetricity, exaggeration, and modification. The results of this study demonstrate the possibility of creating diverse as well as economical designs through the reduction of production.

한중FTA가 중국 시장에 미치는 영향에 관한 연구 -한국 화장품을 수출 중심으로-

유환,장휘 대한경영학회 2019 대한경영학회 학술발표대회 발표논문집 Vol.2019 No.1

기반 기술 : 주석 도금한 커넥터의 접촉 하중의 변화에 의한 전기 접촉저항 변화에 관한 연구

유환신 ( Hwan Shin Yu ),오만진 ( Man Jin Oh ),박형배 ( Hyung Bae Park ),유환신 ( Hwan Shin Yu ),오만진 ( Man Jin Oh ),박형배 ( Hyung Bae Park ) 한국항행학회 2014 韓國航行學會論文誌 Vol.18 No.4

전기 커넥터에 영향을 주는 프레팅 부식 요인 중 하나인 접촉 부하의 영향을 조사하기 위하여, 프레팅 부식 표본 쌍을 두께 3μm의 두께를 갖는 주석으로 도금된 황동 표본을 사용하여 제조하였다. 접점의 전기저항은 프레팅 부식 시험 기간 동안 측정되었다. 프레팅 주기에서 저항은 증가하였다. 저항의 변화는 3단계로 나눌 수 있다. 첫 번째 단계는 미미하고 안정적인 저항을 나타내었다. 두 번째 단계는 저항이 꾸준한 증가를 보여 주었다. 그리고 세 번째 단계는 매우 높고 간헐적인 저항을 보여주었다. 실패주기(Nf)와 접촉력(P) 사이의 관계는 다음과 같이 표현될 수 있다. 각각의 하중, 변위, 온도 등 다양한 조건에서 프레팅 테스트를 통해 다양한 환경 조건 하에서 매우 높고 간헐적인 저항에 대응 전기 커넥터의 실패주기 예측공식의 표현이 가능할 것이다. In order to investigate the effect of contact load, which is one of the fretting corrosion factors affecting the electric connector, a coupled fretting corrosion specimens were prepared using a tin-plated brass coupon with a thickness of 3 μm. Electric resistance of the contact was measured during the fretting corrosion test period. There was increase in resistance with fretting cycles. The change in resistance can be classified by 3 stages. The first stage exhibited low and stable resistance. Second stage showed steady increment of the resistance and third stage showed very high and intermittent resistance. The relationship between the failure cycle (Nf) and contact force (P) can be drawn as; It is possible to draw the prediction equation for the failure cycle of the electric connector corresponding to the very high and intermittent resistance under various environment conditions through the fretting tests under various conditions such as load, displacement, temperature.

은행 금융상품에서 프라이빗 뱅커의 전문투자형 사모펀드 추천 의사결정

유환,이영재 한국정보시스템학회 2019 情報시스템硏究 Vol.28 No.4

Purpose The study aims to develop a data-based decision model for private bankers when recommending hedge funds to their customers in financial institutions. Design/methodology/approach The independent variables are set in two groups. The independent variables of the first group are aggressive investors, active investors, and risk-neutral type investors. In the second group, variables considered by private bankers include customer propensity to invest, reliability, product subscription experience, professionalism, intimacy, and product understanding. A decision-making variable for a private banker is in recommending a first-rate general private fund composed of foreign and domestic FinTech products. These contain dependent variables that include target return rate(%), fund period (months), safeguard existence, underlying asset, and hedge fund name. Findings Based on the research results, there is a 94.4% accuracy in decision-making when the independent variables (customer rating, reliability, intimacy, product subscription experience, professionalism and product understanding) are used according to the following order of relevant dependent variables: step 1 on safeguard existence, step 2 on target return rate, step 3 on fund period, and step 4 on hedge fund name. Next, a 93.7% accuracy is expected when decision-making uses the following order of dependent variables: step 1 on safeguard existence, step 2 on target return rate, step 3 on underlying asset, and step 4 on fund period. In conclusion, a private banker conducts a decision making stage when recommending hedge funds to their customers. When examining a private banker's recommendations of hedge funds to a customer, independent variables influencing dependent variables are intimacy, product comprehension, and product subscription experience according to a categorical regression model and artificial neural network analysis model.

대·중소기업 공급망에 대한 CSR과 ESG 발전 방향 연구 :현대자동차, 대상(주) 사례연구를 중심으로

유환철,최종인 공주대학교 KNU 기업경영연구소 2023 기업경영리뷰 Vol.14 No.3

Recently, ESG, a non-financial indicator of environment, society, and governance, has been highlighted as a major issue due to the coronavirus pandemic, social polarization, and the urgent need to arouse climate change. Since UN PRI and Paris Agreement, companies & investors have become increasingly interested in ESG, and laws & regulations related to ESG such as CSRD and CSDD have been specifically legislated at the global level such as EU. The scale of ESG investment by large investment companies and financial institutions is also increasing. Major multinational companies such as Apple, BMW, and Google are also requesting data on ESG implementation and performance, including carbon neutrality, not only from themselves but also from their suppliers in the global supply chain. In the wake of this, Korean conglomerates such as Hyundai Motor, POSCO, and Samsung Electronics are also practicing ESG as part of their social responsibility and are requesting their suppliers to do the same. In this atmosphere, the perspective of social responsibility of Korean large-sized companies is shifting from traditional CSR management method to ESG management method. In particular, the perspective of corporate social responsibility for the supply chains of large-sized company to small & medium-sized companies is rapidly shifting to ESG management method. To understand this situation, we examined a theoretical review of CSR and ESG as well as the international and domestic trends related to ESG. We also identified the impetuses about shifting to ESG management method. We analyzed the case of Hyundai Motor Company’s supply chain and the case of Daesang Corporation’s supply chain to identify trends in the actual corporate field. Thus we were able to derive three research propositions. First, Korean large-sized companies will shift their perspective of corporate social responsibility from traditional CSR management method to ESG management method. Second, Korean large-sized companies will shift their operating perspective of social responsibility towards their suppliers in the supply chain from traditional CSR management method to ESG management method. Third, Korean large-sized companies will support their suppliers to prevent ESG risks and strengthen ESG capabilities of their suppliers in the supply chain. Our conclusion from our research on the impact of rise of ESG issues in the supply chain, is that while the core concept of CSR remains the same, The corporate social responsibility of the supply chain will be running dominantly by ESG management method. 최근 코로나 팬데믹, 사회적 양극화, 기후변화 대응 대한 시급성 환기 등으로 인해 환경(Environment), 사회(Social), 지배구조(Governance)라는 비재무적 지표인 ESG가 주요 이슈로 부각하고 있다. UN PRI, 파리협약 이후 ESG에 대한 기업과 투자자의 관심이 높아지고, EU 등 글로벌 차원에서 정보공시 의무, 공급망 실사 등 ESG 관련 법적 규범들이 구체적으로 입법화되고 있다. 대형 투자사와 금융기관의 ESG 투자 규모도 늘어나는 추세이다. 애플, BMW, 구글 등 주요 글로벌 기업들은 자사뿐만 아니라 전 세계 공급망 내 협력사들에게 탄소중립 등 ESG 이행과 그 실적자료를 요청하는 동향도 파악되고 있다. 이런 여파로 인해 현대자동차, 포스코, 삼성전자 등 국내 대기업들 역시 사회적 책임의 일환으로 ESG를 실천하고 있고 이를 협력사까지 요구하고 있는 상황이다. 이런 상황에서 국내 대기업의 사회적 책임의 관점이 전통적인 CSR 관리방식에서 ESG 관리방식으로 전환하는 분위기도 감지된다. 특히, 대·중소기업 공급망에 대한 기업의 사회적 책임의 관점이 ESG 관리방식으로 빠르게 전환되고 있다. 이를 파악하기 위해 CSR과 ESG에 대한 이론적 고찰과 더불어, ESG와 관련한 국내·외 동향을 통해 기업의 사회적 책임의 관점이 ESG 관리방식으로 전환하게 된 원인을 파악해보았다. 실제 기업 현장의 동향을 파악하기 위해 현대자동차의 공급망 사례와 대상(주)의 공급망 사례를 분석해 보았다. 이를 통해 세 가지 연구명제를 도출할 수 있었다. 첫째, 국내 대기업은 자사에 대한 사회적 책임의 관점을 전통적인 CSR 관리방식에서 ESG 관리방식으로 전환할 것이다. 둘째, 국내 대기업은 공급망 내 협력사에 대한 사회적 책임의 관점을 전통적인 CSR 관리방식에서 ESG 관리방식으로 바꿀 것이다. 셋째, 국내 대기업은 공급망 내 협력사의 ESG 리스크 방지와 ESG 역량 향상을 위해 협력사에 대한 지원을 강화할 것이다. 사회적 책임의 관점에서 ESG 이슈의 부각이 대·중소기업 공급망에 미치는 영향에 관한 연구를 통해 얻은 결론은, 기업의 사회적 책임이라는 CSR의 핵심 개념은 변함없지만, 기업의 사회적 책임을 실제로 운영하는 관점은 ESG 관리방식이 대세가 될 것이라는 점이다.

국내 제품에 대한 CPFR 적용 사례

유환국 한국물류협회 2004 물류혁신 컨퍼런스 Vol.12 No.2

Fully Transparent, Non-volatile Bipolar Resistive Memory Based on Flexible Copolyimide Films

유환철,김문영,홍민기,남기용,최주영,이광훈,백경구,김경국,조수행,정찬문 대한금속·재료학회 2017 ELECTRONIC MATERIALS LETTERS Vol.13 No.1

Partially aliphatic homopolyimides and copolyimides were prepared from rel-(1'R,3S,5'S)-spiro[furan-3(2H),6'-[3]oxabicyclo[3.2.1]octane]-2,2',4',5(4H)-tetrone (DAn), 2,6-diaminoanthracene (AnDA), and 4,4'-oxydianiline (ODA)by varying the molar ratio of AnDA and ODA. We utilized these polyimidefilms as the resistive switching layer in transparent memory devices. WhileWORM memory behavior was obtained with the PI-A100-O0-based device(molar feed ratio of DAn : AnDA : ODA = 1 : 1 : 0), the PI-A70-O30-baseddevice (molar feed ratio of DAn : AnDA : ODA = 1 : 0.7 : 0.3) exhibitedbipolar resistive switching behavior with stable retention for 104 s. This resultimplies that the memory properties can be controlled by changing thepolyimide composition. The two devices prepared from PI-A100-O0 and PIA70-O30 showed over 90% transmittance in the visible wavelength rangefrom 400 to 800 nm. The behavior of the memory devices is considered to begoverned by trap-controlled, space-charge limited conduction (SCLC) andlocal filament formation.

사물 인터넷 기반의 저 전력 보안단말 시스템을 위한 연구

유환신 한국기계기술학회 2023 한국기계기술학회지 Vol.25 No.4

Recent, there has been a need for a terminal device with artificial intelligence to detect emergency situations in various means of transportation to prevent overdischarge of the battery even when parking the vehicle for a long time so that the driver can properly prepare. The transmission system, which guides the situation and location information of the vehicle, uses AHD video technology and RTOS technology to reduce the load of wireless networks by increasing the video playback rate through UDP implementation by WiFi, and stabilizes through wireless networks and low-power sensors using LoRa services.

Fully Transparent, Non-volatile Bipolar Resistive Memory Device Based on Flexible Copolyimide Layer

유환철,김문영,홍민기,남기용,최주영,조수행,정찬문 한국고분자학회 2017 한국고분자학회 학술대회 연구논문 초록집 Vol.42 No.1