Measurement and Evaluation of Scatter Fractions for Digital Radiography with a Beam-Stop Array

최유나,조효민,김이슬,안수정,김희중,Choi, Yu-Na,Cho, Hyo-Min,Kim, Yi-Seul,An, Su-Jung,Kim, Hee-Joung Korean Society of Medical Physics 2010 의학물리 Vol.21 No.1

X-선 영상 촬영 시 피사체에 조사되는 X-선은 피사체 내부에서 필연적으로 산란을 일으킨다. 산란선은 영상시스템에 도달하여 영상의 대조도를 저하시키고 전체 농도(Background)를 불균일하게 만든다. 현재 학계의 연구 동향은 산란선에 의한 영상의 화질 저하를 방지하기 위한 방법 고안에 초점을 두고 있다. 본 연구의 목적은 영상에서의 scatter fraction을 정확하게 측정하여 영상시스템의 개선에 기여하고 대조도에 영향을 미치는 인자의 정량적 평가를 최적화하기 위함에 있다. Scatter fraction을 정확하게 측정하기 위하여 beam stop array를 제작하였다. 제작한 beam stop array를 이용하여 영상을 획득하고, 영상의 각 부위에서의 scatter fracton 측정을 자동화하기 위해 MATLAB을 이용한 프로그램(SFC: Scatter Fraction Calculator)을 개발하였다. 그리드 유 무와 air gap 효과에 따른 scatter fracton의 비교를 통하여 beam stop array와 SFC 프로그램의 효용성을 평가하였다. 그리드가 있을 경우의 scatter fraction이 그리드가 없는 경우에서 보다 낮은 값으로 측정되었으며 air gap이 증가함에 따라 scatter fracton이 감소함으로써 효용성을 입증했다. Beam stop array와 SFC 프로그램은 입증된 효용성을 기반으로 임상에서 흉부뿐 아니라 인체의 여러 부위에 이를 활용할 수 있을 것으로 기대된다. Scatter radiation considerably affects radiographic image quality by reducing image contrast and contributing to a non-uniform background. Images containing a large portion of scatter radiation may result in an incorrect diagnosis. In the past few years, many efforts have been made to reduce the effects of scatter radiation on radiographic images. The purpose of this study is to accurately measure scatter fractions and evaluate the effectiveness of beam-stop arrays. To measure scatter fraction accurately, a beam-stop array and the SFC (Scatter Fraction Calculator) program were developed. Images were obtained using the beam-stop array for both an anti-scatter technique with an anti-scatter grid and an air gap technique. The scatter fractions of the images were measured using the SFC program. Scatter fractions obtained with an anti-scatter grid were evaluated and compared to scatter fractions obtained without an anti-scatter grid. Scatter fractions were also quantitatively measured and evaluated with an air gap technique. The effectiveness of the beam-stop array was demonstrated by quantifying scatter fractions under various conditions. The results showed that a beam-stop array and the SFC program can be used to accurately measure scatter fractions in radiographic images and can be applied for both developing scatter correction methods as well as systems.

역사경관 유지를 위한 도시재생지역내 공동주택 건축특성 분석

최유나(Yu Na Choi),전병권(Byung Kweon Jun) 한국생태환경건축학회 2020 한국생태환경건축학회 논문집 Vol.20 No.2

패러디와 데페이즈망을 활용한 시각문화 미술교육

최유나(Choi, Yu-Na),손지현(Sohn, Jihyun) 한국미술교육학회 2010 美術敎育論叢 Vol.24 No.2

본 연구는 중학교 학생을 대상으로 하여 패러디와 데페이즈망을 활용한 시각문화 미술교육의 사례이다. 시각문화 미술교육은 학생들의 일상생활의 미적경험을 학교 교육의 장에 포함시켜 시각적 문해력을 향상시키고 이미지가 우리에게 주는 영향을 비판적으로 사고할 수 있는 능력을 함양시키고자 한다. 이를 위해 연구에 참여한 학생들은 공익 광고의 의미를 생각해보고 패러디와 데페이즈망을 활용하여 공익광고를 제작하는 활동을 하였다. 본 연구를 통한 교육적 효과는 다음과 같다. 첫째, 시각문화에 대한 해석을 할 수 있게 되고, 둘째, 학생의 문화를 반영한 작품을 제작할 수 있게 되었고, 셋째, 해석, 감상, 제작 활동이 결합되어 공익광고의 표현 활동에 좀더 자신감을 갖게 되었으며, 마지막으로 일상 생활 속에서 미술의 중요성을 인식하고 시각문화를 자신의 삶과 연결시킬 수 있게 되었다. This study reports on process and results of visual culture art education program for middle school students utilizing parody and d?paysement. Parody is used for teaching strategy for deconstructing original text and reconstructing students' text on their life and social concerns. Students who participated in the art class studied parody concept and interpreted artworks and advertisement using parody. Parody is not only a humorous piece of writing, artwork, music etc. but also social comment on issues of public and personal stories. The students studied and interpreted visual culture using d?paysement. They made public advertisement using parody and d?paysement. The learners' reactions and interaction processes were analyzed through the researcher’s journal, individual and group activity sheets, pre- and post- activity surveys, work plans, final products, and self- and peer evaluation. The implication of this study is as follows. First, students could interpret visual culture and became capable of expressing their ideas and thoughts in their images by making advertisements of their own. Second, students could relate their life experience in socio-cultural context to art making. They expressed issues of study, friendship, family, school life, school violence, etc. Third, visual culture art class integrated interpretation, appreciation, and artmaking. Fourth, students realized art plays an important role of everyday aesthetic experience.

영국의 역사적 환경 보존제도에 관한 연구

최유나(Choi, Yu Na),전병권(Jun, Byung-Kweon) 대한건축학회 2018 대한건축학회 학술발표대회 논문집 Vol.38 No.2

입지요인이 편의점 성과에 미치는 영향에 관한 연구

최유나(Yu-Na Choi),정의철(Eui-Chul Chung) 건국대학교 부동산도시연구원 2012 부동산 도시연구 Vol.5 No.1

본 연구에서는 편의점 입지요인을 인구 및 가구요인, 지역요인, 매장요인, 경쟁요인으로 구분하고 수도권 서부지역을 대상으로 입지를 구성하는 변수들이 편의점의 매출액, 이익, 방문객 수에 미치는 영향을 실증분석하였다. 실증분석 결과에 따르면 편의점 성과는 해당 매장이 입지한 위치에서의 20대 유동인구, 해당 매장의 상권, 전면길이 및 접면수, 버스정류장까지의 거리, 매장면적, 해당 공간의 이전 사용용도, 영업기간, 그리고 경쟁점포 수에 영향을 받는 것으로 나타났다. 보다 구체적으로 20대 유동인구가 많을수록, 유흥역세상권일수록, 전면길이가 길고 접면수가 많을수록, 버스정류장까지의 거리가 짧을수록, 매장개설 이전에 해당 공간이 수퍼나 개인편의점으로 이용된 경우일수록, 영업월수가 길수록, 그리고 경쟁점포 수가 적을수록 단위면적당 매출액과 이익은 증가하는 것으로 나타났다. 한편 단위면적당 매출액은 매장면적이 넓을수록 감소하는 것으로 나타났다. 본 연구는 베이비 붐 세대의 본격적인 은퇴, 청년 인구의 취업에 대한 어려움, 조기 퇴직 등으로 인해 자영업 중심의 창업이 증가하고 있는 시기에 창업의 주된 업종으로 편의점 개설이 관심을 보이고 있으며 특히 프랜차이즈를 통한 편의점 개설은 증가 추세에 있는 시점에서 영업기간이 비교적 짧은 편의점을 표본으로 선택하여 실증 분석함으로써 편의점을 통한 신규 창업에 시사점을 제공하였다는 점에 의의를 둘 수 있다. This paper empirically analyzes the effects of locational factors on financial performance of convenient stores. As for financial performance, we consider total sales per store area and monthly profit. We also analyze what determines the number of customers visiting a store each day. As for locational factors, the number of floating population with the age of 20’s, store length and the number of sides, distance to the nearest bustop, store area, store operation period, and the number of nearby competitive stores are considered. Our empirical results are mainly consistent with what is expected from the theory. It is found that the floating population with the age of 20’s, store length and the number of sides, the distance to the nearest bustop, and the store operation period are factors commonly affecting the convenient store performance. It is expected that our analysis provides useful implications to whom currently considering to open convenient stores as their new occupations.

시노노메 코단(東雲 CODAN)의 공용공간 분석 연구

최유나(Choi, Yu-Na),김경연(Kim, Kyong-Yon),전병권(Jun, Byung-Kweon) 대한건축학회 2017 대한건축학회 학술발표대회 논문집 Vol.37 No.1

나중심'시대, 유희적 디자인 프로세스에 의한 포장디자인 표현연구 - 화장품 포장디자인 중심으로 -

최유나(Choi Yu-Na) 한국상품학회 2003 商品學硏究 Vol.- No.30

Evolution is a better term to describe current Korean society than transition. Thus it is difficult to define the whole feature in a single term. This is not because our understanding and insight has decreased but the trend is now rapidly changing. Korea has faced a progress in packaging design due to the success of the 1988 Seoul Olympics. But this was mainly due to the quantitative growth which has been stimulated by economic factors, not by technological progress. Thus a unique and creative progress in packaging design can not be expected due to the weakness in technological factors and lack of human resources. We usually think packaging design as a 'graphic design to give visual effect' or an 'effective method to stimulate purchase'. But one must have a thorough under standing of the interconnected factors in the industry, social trends and consumer trends to develop a reasonable planning in packaging design. After the industrial revolution, the manufacturing industry transformed itself to a manufacturer's market and this trend changed to a consumer's after the financial crisis in 1927. Thus the sale of a product was the most significant factor In mass production and a mass consuming market had to be established in order to enable mass production. Competition became fierce and studies regarding consumer behavior and marketing strategies was conducted. Consumer purchase motives was the first priority and production methods concerning consumers became more important. Competition became more fierce than ever and distribution was made in a more effective method. Corporations developed various methods to cope with this new method by increasing product quality, package design and using a variety of promotion techniques. As a result packaging which only function was to considered to deliver and store a product combined with designing concept and this worked as important factor in changing purchasing actions. Especially, an organized and scientific approach to stimulate consumer's sensitive taste and satisfaction is necessary. Therefore a thorough understanding in the features and changes of packaging methods is an important precondition in studying packaging design in the era of sensitivity. Packaging not only serves as a method to store and deliver a product but as a medium of mutual communication. The consumer will select a product which has a more sensitive appearance given that the quaJity or the service is equal. This pattern emerged with changes in purchasing patterns and changes in industry structures etc. Thus as packaging carries out much more functions than an advertisement promotion, a special study is necessary. Hence chapter 2 in this dissertation describes the changes in consumer con sciousness and the definition of modern packaging design. We will describe in chapter 3 the concept of sensitive packaging design and the changes in packaging designing methods. Also the scope and the concept of this study will be presented. Chapter 4 will describe packaging design in cosmetics based on theories argued in the previous chapters. Chapter 5 will describe future strategies concerning packaging design. The main purpose of this dissertation is to apply packaging design to cosmetics, which a sensitive approach can easily be observed and to create a new formative factor in Korea's packaging design industry. We hope this study will be used by many designers and prove to be useful.

차세대 열차통신네트워크 기술 동향 및 분석

최유나(Yu-na Choi),고경준(Kyeong-jun Ko),변일무(Ilmu Byun) 한국통신학회 2021 韓國通信學會論文誌 Vol.46 No.7

이커머스(E-commerce) 기업의 물류관리 과정에 관한 연구 -Fulfillment 중심으로-

최유나 ( Choi Yu Na ),이도형 ( Lee Do Hyung ) 한중사회과학학회 2022 한중사회과학연구 Vol.20 No.4

계속되는 정보 통신 기술의 발달로 온라인에서 공간과 시간의 제약 없이 물건을 구매할 수 있게 되었고, 이커머스 산업이 성장할 수 있는 원동력이 되었다. 산업의 발달과 함께 증가한 물류량을 해결하고 고객의 니즈를 충족하기 위해서 이커머스 기업은 인프라 확대에 투자하고 있는 실정이다. 따라서, 본 연구에서는 국내 이커머스 기업의 물류관리 변천사와 Fulfillment를 분석하고, 해외의 아마존과 국내 기업 쿠팡의 물류 시스템을 비교하며 국내 도입된 Fulfillment 센터의 문제점(낮은 자동화 비율과 막대한 비용, 재고 관리의 위험성)을 살펴보고 이를 바탕으로 본 연구는 세 가지의 개선전략을 제시하였다. 첫째, 우수물류 기업 인증제도를 개선하여 기술 도입의 기회를 제공하고 유지를 도와 4PL로 전환을 추구하는 것이다. 둘째, 빅데이터를 활용한 수요 예측을 통해 재고 관리를 하여 손실을 줄이는 것이다. 셋째, 마이크로 Fulfillment 센터를 확대하여 소형 물류 거점을 확보하고 재고 상태와 배송의 질을 제고하는 것이다. 또한, 국내 물류 시스템의 발전을 위해서는 정부의 역할이 중요하다. 이를 통해서 국내 물류산업의 문제점을 분석하고 개선 전략과 시사점을 제공하고자 한다. The continuous development of information and communication technology(ICT) has allowed people to purchase goods online without space and time constraints, and has become a driving force for the growth of the E-commerce industry. In order to solve the increased logistics volume with the development of the industry and meet the needs of customers, companies invested in expanding infrastructure. This study analyzed the logistics management transformation and Fulfillment of South Korea E-commerce companies, compared the logistics system of Amazon and Coupang, and revealed the problems of the Fulfillment Center in Korea. There are low automation rates, huge costs, and risk for inventory management. This study presented three improvement strategies. First, it aims to improve the Certification Excellent Logistics Company to provide opportunities to introduce and maintain technology, and to pursue the transition to 4PL. Second, it is to reduce losses by managing inventory through demand prediction using big data. Third, expand the micro-fulfillment center to secure small logistics bases and improve inventory status and delivery quality. In addition, the role of the government is important for the development of the domestic logistics system. Through this, it is intended to analyze the problems of the Korean logistics industry and provide improvement strategies and implications. The logistics systems of Amazon and Coupang, a South Korea company, were compared. Through this, we intend to identify some problems in South Korea logistics, present improvement strategies, and provide implications.

익모초 에탄올 추출물의 항산화 및 항염증 활성

최유나 ( Choi You-na ),최유경 ( Choi Yu-kyung ),난리 ( Nan Li ),추병길 ( Choo Byung-kil ) 한국유기농업학회 2020 韓國有機農業學會誌 Vol.28 No.4

Leonurus japonicus (L. japonicus) Houtt., a biennial plant in the Lamiaceae family is broadly distributed in Asia such as Korea, China, Japan. The aerial part of L. japonicus is used as a traditional medicine to treat uterine disease including dysmenorrhea, amenorrhea, sterility. In this study, we examined the antioxidant and anti-inflammatory effects of L. japonicus ethanol extracts. The antioxidant activity of L. japonicus was measured by total polyphenol and flavonoid content, and DPPH, ABTS scavenging, reducing power activity, and intracellular ROS expression assay. The anti-inflammatory effects were measured by nitric oxide (NO), cytokines (TNF-α and IL-1β) production and inflammatory protein expression in LPS-induced RAW 264.7 cells. Total polyphenol and flavonoid content of L. japonicus were 51.40 ± 0.47 mg of gallic acid equivalents/g and 73.28 ± 0.10 mg of rutin equivalents/g respectively. DPPH, ABTS radical scavenging activity and reducing power activity tended to increase concentration-dependent and treatment L. japonicus with 400 μg/mL reduced ROS production by 69.5%. Furthermore, L. japonicus inhibited NO, TNF-α and IL-1β production in a concentration-dependant manner and reduced the expression levels of inflammatory proteins via regulating NF-ĸB, MAPK pathway. Therefore, we suggest that L. japonicus could be a natural antioxidants and medicinal source to treat oxidative stress and inflammation- related disease.