다공성 매질 위에서의 액적 충돌에 대한 수치적 연구

최문혁(Moonhyeok Choi),손기헌(Gihun Son) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

외부 유동 조건에서 다공성 매질내의 액적 증발에 관한 수치적 연구

최문혁(Moonhyeok Choi),손기헌(Gihun Son) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

Numerical simulation is performed for droplet evaporation in a porous medium under an external flow condition. A level-set (LS) method for tracking the gas-liquid interface is modified to include the effects of evaporation and porous drag and capillary forces. The local volume averaged conservation equations of mass, momentum, energy, and vapor fraction for the porous region are simultaneously solved with the conservation equations for the external fluid region. The evaporation process includes the penetration of a droplet into the porous medium and the convective and diffusive heat and mass transfer to the air. The computations are conducted to investigate the effects of external flow velocity, droplet size, temperature, porosity on the droplet deformation and evaporation.

고주파통증치료기 개발 및 통증완화에 대한 유효성 검증

최문혁(Moon Hyeok Choi),김승훈(Seung-Hun Kim),박예은(Park Ye-Eun),김영관(Young-kwan Kim),이상식(Sang-sik Lee) 대한전기학회 2020 정보 및 제어 심포지엄 논문집 Vol.2020 No.10

다양한 식물에서의 PDRN(Polydeoxyribonucleotide) 추출 수율 비교 및 상처치유 효능 분석

송미희,최문혁,정진형,이상식,정우영,Song, Mi-Hee,Choi, Moon-Hyeok,Jeong, Jin-Hyoung,Lee, Sang-Sik,Jeong, Woo-Young 한국정보전자통신기술학회 2022 한국정보전자통신기술학회논문지 Vol.15 No.5

PDRN (Polydeoxyribonucleotide) is a DNA-derived polymer that promotes self-renewal of damaged cells and tissues as a tissue regeneration active material. PDRN is a DNA fragment cut into small sizes by various physical or chemical methods. When administered to the body, PDRN binds and stimulates the adenosine A2A receptor on the surface of tissue cells to promote cell regeneration, accelerate wound healing, and reduce pain. Although PDRN is prepared from testis or semen of fish in most cass, PDRN extraction from various plants species was performed in the present study. Among 7 tested plant species, the highest DNA yield and purity was obtained form mugwort (Chrysanthemum coronarium, C.c), followed by broccoli (Brassica oleracea, B.o). Then, we evaluated the in vitro wound healing capacity of PDRNs prepared from these two selected plants. PDRN from C.c and B.o. significantly stimulated the wound healing process at ㎍/ml range. The present study suggests that PDRN from plant species can be an effective alternative to PDRN from marine organism.

쑥갓(Chrysanthemum coronarium L.) PDRN(Polydeoxyribonucleotide)의 항염증 효능 분석

송미희,최문혁,정진형,이상식,정우영,Song, Mi-Hee,Choi, Moon-Hyeok,Jeong, Jin-Hyoung,Lee, Sang-Sik,Jeong, Woo-Young 한국정보전자통신기술학회 2022 한국정보전자통신기술학회논문지 Vol.15 No.5

Chrysanthemum coronarium L. contains various antioxidants such as beta-carotene, vitamins A and C, and polyphenols, and is known to have anti-inflammatory effects. Under the assumption that the PDRN contained in the extract can mediate the anti-inflammatory response, the mouse macrophages, RAW264.7 cells, were stimulated with LPS to induce the conversion to inflammatory cells, and then the addition of PDRN extracted from the extract was effective in inhibiting inflammation. It was analyzed whether there was The gene expression of IL-1β and TNF-α was used as an anti-inflammatory index, and the relative expression levels of each gene were confirmed by RT-PCR. As a result, RT-PCR confirmed the effect of PDRN-induced inhibition of inflammation in both IL-1β and TNF-α genes. Therefore, based on this study, it is considered to be a precedent data that can be developed as a treatment for inflammatory diseases, and it will be helpful in research and development of a treatment that can improve the anti-inflammatory mechanism.

단백질 독소 리신의 생화학적 분석법 정립에 관한 연구

김유리,최문혁,장윤정 육군사관학교 화랑대연구소 2024 한국군사학논집 Vol.80 No.1

리신은 피마자(Ricinus communis, 아주까리)씨에 1∼5% 함유되어있는 단백질 독소로, 세포 내 단백질 합성을 억제함으로써 독성을 나타낸다. 보툴리눔 독소에 비해 독성은 1,000배 정도 약하지만, 재료를 쉽게 구할 수 있고 대량생산이 용이하다는 점에서 테러 사용 가능성이 높은 물질이다. 체내 흡수 시 증상 발현이 빠르고 치명적이므로 의심 환경시료 내 리신 존재 유무의 신속하고 정확한 분석은 생물 상황 대응을 위해 필수적인 과정이다. 본 연구에서는 리신의 생화학적 특성 분석 및 검출을 위하여 Western blot 분석법을 구축하였으며, 이를 통해 리신 단백질의 분자량 확인 및 정성분석이 가능함을 확인하였다. 특히, 단백질 전기영동을 통해 환원(reduced) 및 비환원(non-reduded) 조건에서의 리신 내 이황화 결합(disulfide bond)으로 연결된 2개의 소단위체(subunit)를 확인하였으며, 각 subunit의 항체(Ricin A-chain, B-chain antibody)를 이용하여 subunit 단위에서의 정성분석이 가능함을 확인하였다. 본 연구를 통한 리신의 정밀분석법 구축으로 군 내 생물 대응 능력 향상에 기여할 수 있을 것으로 기대한다. Ricin is a protein toxin contained 1-5% in Ricinus communis(Castor bean) seeds, which causes toxicity by inhibiting protein synthesis in human cells. Although the toxicity is 1,000 times weaker than that of botulinum toxins, it is a highly potential materials to be used for terrorism because raw material are easily available and mass production of toxins is easy. When Ricin is absorbed into the body, symptoms are fast and fatal compared to biological agents. So quick and accurate analysis of the presence or absence of ricin in a suspected biological situation is an essential process for response and follow-up. In this study, to identify the biochemical properties of ricin, we established western blot analysis method which can confirmed the molecular weight and qualitative analysis of ricin protein. In particular, two subunits connected by disulfide bonds in ricin under reduced and non-reduced conditions were identified by protein electrophoresis method. And we checked that the qualitative analysis in subunit level of ricin protein was possible using antibodies(Ricin A-chain, B-chain antibody) of each subunit. It is expected that the establishment of analysis method of ricin through this study will contribute to the improvement of biological response capabilities.

서비스워커와 해시를 이용한 통신 데이터 소모 감소를 위한 웹 콘텐츠 갱신 알고리즘 설계

김현국,박진태,최문혁,문일영 한국항행학회 2019 韓國航行學會論文誌 Vol.23 No.2

The existing web page was downloaded and provided to the user every time the user requested the page. Therefore, if the same page is repeatedly requested by the user, only the download for the same resource is repeated. This is a factor that causes unnecessary consumption of data. We focus on reducing data consumption caused by unnecessary requests between users and servers, and improving content delivery speed. Therefore, in this paper, we propose a caching system and an algorithm that can reduce the data consumption while maintaining the latest cache by comparing the hash value using the hash function that can detect the change of the file requested by the user. 기존 웹 페이지는 사용자가 해당 페이지를 요청할 때 마다 새로운 페이지를 다운로드 받아 사용자에게 제공하였다. 따라서 동일한 페이지를 사용자가 반복해서 요청할 경우 동일한 리소스에 대한 다운로드만을 반복하게 된다. 이는 불필요한 데이터의 소비를 발생시키는 요인이다. 본 논문에서는 사용자와 서버간의 불필요한 요청에 의해 발생하는 데이터의 소모를 감소시키고, 콘텐츠 제공 속도를 향상시키는 대에 초점을 맞추었다. 따라서 이를 방지하기 위하여 본 논문에서는 캐싱 시스템과 사용자가 요청하는 파일의 변경을 감지할 수 있는 해시 함수를 이용한 해시 값의 비교를 통해 항상 최신 캐시를 유지하면서 데이터 소모를 줄일 수 있는 알고리즘에 대하여 논하고, 웹 콘텐츠의 속도 향상을 위한 서비스 워커 기반의 캐싱 시스템을 설계하고 성능을 평가하였다.

서비스워커 기반의 캐싱 시스템을 이용한 웹 콘텐츠 로딩 속도 향상 기법

김현국,박진태,최문혁,문일영 한국항행학회 2019 韓國航行學會論文誌 Vol.23 No.1

The web is one of the most intimate technologies in people's daily lives, and most of the time, people are sharing data on the web. Simple messenger, news, video, as well as various data are now spreading through the web. In addition, with the emergence of Web assembly technology, the programs that run in the existing native environment start to enter the domain of the Web, and the data shared by the Web is now getting wider and larger in terms of VR / AR contents and big data . Therefore, in this paper, we have studied how to effectively deliver web contents to users who use Web service by using service worker that can operate independently without being dependent on browser and cache API that can effectively store data in web browser. 웹은 사람들의 일상생활에 있어 가장 밀접한 기술 중 하나로 오늘날 대부분의 사람들은 웹을 통해 데이터를 공유하고 있다. 단순 메신저, 뉴스, 영상뿐만 아니라 다양한 데이터가 현재 웹을 통하여 전파되고 있는 셈이다. 또한 웹 어셈블리 기술이 등장하면서 기존 네이티브 환경에서 구동되던 프로그램들이 웹의 영역에 진입하기 시작하면서 웹이 공유하는 데이터는 이제 VR/AR 콘텐츠, 빅데이터 등 그 범주가 점차 넓어지고, 크기가 거대해지고 있다. 따라서 본 논문에서는 브라우저에 종속적이지 않고 독립적으로 동작이 가능한 서비스워커와 웹 브라우저 내에 데이터를 효과적으로 저장할 수 있는 캐시 API를 활용하여 웹 서비스를 사용하는 사용자들에게 웹 콘텐츠를 효과적으로 전달할 수 있는 방법을 제시하였다.

패션 이미지 카테고리 분류를 이용한 웹사이트

이석준(Seok-jun Lee),최문혁(Moon-hyuk Choi),이학재(Hak-jae Lee),김소영(So-yeong Kim),문일영(Il-young Moon) 한국정보통신학회 2019 한국정보통신학회 종합학술대회 논문집 Vol.23 No.2

옷을 구매할 때 중요하게 여겨지는 요소 중 하나는 바로 다른 부위의 옷과의 조합이다. 여러 온라인 스토어에서는 판매자가 임의로 조합한 옷들을 보여주기도 한다. 그러나, 이는 사용자가 원하는 조합을 알아보기에는 한계가 있다. SNS 그리고 인공지능 기술을 융합하여 패션 조합에 대한 검색 문제를 해결하는 방안을 연구하였다. 웹 사이트를 기반으로 사람들이 자신의 패션 사진을 웹사이트상에 업로드하여 타인과 공유하며 조합을 선택하여 선택된 조건과 일치하는 사진들을 제공한다. 그리고 이를 바탕으로 통계적으로 어떤 옷이 많이 업로드되었고 어떤 조합이 인기가 있는지 확인할 수 있도록 한다. 인공지능 기술의 경우 인공신경망의 한 종류인 Convolutional Neural Network(이하 CNN)을 이용한다. CNN을 통한 이미지 카테고리 분류를 해당 웹사이트와 연동하여 사용한다. 이미지 속에서 사람을 인식한다. 그리고 성별, 상의의 종류 및 무늬와 하의의 종류 및 무늬를 분류한다. 이 정보들을 저장하여 조합 검색 기능 및 통계 기능에 활용한다. 이를 통해 기대하는 효과는 다음과 같다. 먼저, 웹사이트를 통해 사용자는 자신이 원하는 조합을 쉽게 확인할 수 있다. 두 번째는 바로 사람들이 선호하는 패션을 간단하게나마 통계적으로 확인할 수 있다는 점이다, 옷을 구매하거나 판매할 때 이를 바탕으로 정보를 활용할 수 있음을 기대한다. One of the important factors in buying clothes is the combination of clothes from other parts. Many online stores even show a random combination of clothes. However, this is limited to identifying the combinations that users want. The search problem for fashion combinations was studied by merging SNS and artificial intelligence technology. Based on the website, people upload their fashion photos to the website, share them with others, and choose a combination to provide pictures that match the chosen condition. And based on this, we can statistically see which clothes have been uploaded and which combinations are popular. In the case of artificial intelligence technology, it uses a type of artificial neural network called CNN. Image category classification via CNN is used in conjunction with the website concerned. recognize a person in an image They also classify gender, type of top and pattern and type and pattern of bottom. These information are stored and used for combinatorial search and statistical functions. The effects expected from this are as follows: First, through the website, users can easily see the combination they want. The second is that people can simply check their preferred fashion statistically, albeit simply, and expect that information can be used based on it when purchasing or selling clothes.

韓國 運送서비스貿易의 國際競爭力과 比較優位 決定要因-貨物運送, 旅客輸送, 其他運送를 중심으로-

서동균(Seo Dong-Gyun),최문혁(Choi Moon-Chan) 한국항만경제학회 1998 韓國港灣經濟學會誌 Vol.14 No.-

The purpose of this paper is to analyze the service-orientation of the economy and the import/export structure of the trade in services of Korea. so, this paper conduct an empirical study on the comparative advantage determinant factor in connection to the trade in services, while studying how the comparative advantage determinant factors changed structurally. Not only will the results of this study contribute in minimizing the shock of the market opening in the service industry of Korea, it will also help in establishing an effective plan to face up to the foreign inflow as well as providing a basis to prepare the development plans for the Korean service industry and determine an effective opening date.<br/> An empirical study was conducted through theoretical studies and quantitative analysis using documents to achieve the research goals of this paper. For the theoretical study, the concept and various characteristics of the service and trade in services was studied through domestic and foreign thesis papers and literatures, and an effort was made to present a theoretical basis for the empirical study on whether it is possible to apply the traditional comparative advantage theory to the trade in services as well. Next, studies were done to find the affect on the structure of the trade in services in Korea by determining the international competitiveness of the trade in services and its structure.<br/> When the results of the empirical study of the comparative advantage determinant factors for the trade in services of Korea were consolidated, it was discovered that the physical capital and human capital were the comparative advantage determinant factors for shipments, GNP per capita and technical factors were for passenger service, economy of scale was for other transportation<br/> The following methods are presented with the results of the comparative advantage study to develop the service industry of Korea and increase its competitiveness. First, as there is a comparative advantage in the shipment area if there is an adundance of physical capital and human capital, it is essential to increase the number of skilled labor. Therefore, the policy makers will need to give special benefits to graduates of technical schools, colleges and graduate schools, or enforce on site training of employees of companies to increase the number of human capital (skilled labor) oriented labors.