Ba-ferrite의 분산 안정성 및 멜트블로운 PP/Ba-ferrite 부직포의 물리적 특성

최지선,이동진,Choi, Ji-Sun,Lee, Dong-Jin 한국섬유공학회 2006 한국섬유공학회지 Vol.43 No.6

The size of Ba-ferrite particles was decreased from $0.7{\mu}m\;to\;0.5{\mu}m$ by ball-milling according to SEM observation. The surface of Ba-ferrite particles was treated with stearic acid in order to improve dispersion stability in the polymer matrix. PP composites containing the surface treated Ba-ferrite particle as a magnetic particulate filler were prepared in the form of pellet from PP resin and Ba-ferrite powder by a melt compounding using a single extruder. PP/Ba-ferrite composite fabrics by a melt-blown spinning system were prepared. The relationship between the properties of PP/Ba-ferrite composite fabrics and melt-blown processing factors was investigated with these specimens. A fiber diameter and tensile strength were decreased as die to collector distance increased or as screw turning force decreased. The crystallinity was decreased with increasing Ba-ferrite content according to XRD. It was assumed that the orientation of crystalline domain in the neat PP without Ba-ferrite was increased by drawing in mechanical direction, however, the orientation in the PP composite was decreased according to XRD analysis. A coercive force, maximum magnetization and residual magnetization were increased with the screw turning force. According to the result of TGA measurement, the heat resistance was increased with the Ba-ferrite content and decreasing the die to collector distance.

일반화된 신호 압신법에 기반한 향상된 차분전력분석 방법

최지선,류정춘,한동국,박태훈,Choi, Ji-Sun,Ryoo, Jeong-Choon,Han, Dong-Guk,Park, Tae-Hoon 한국정보처리학회 2011 정보처리학회논문지 C : 정보통신,정보보안 Vol.18 No.4

차분전력공격(Differential Power Analysis, DPA)의 효율성은 수집신호 정렬도를 비롯한 다양한 잡음에 많은 영향을 받는다. 최근에 Ryoo등은 잡음 신호를 극복하여 DPA의 분석성능 향상을 가져오는 효과적인 신호처리기법을 소개했다. 본 논문에서는 기존에 제안된 신호처리기법이 적용되지 않은 경우를 보이고, 이에 대한 해결방안으로 차분파형모델(Differential Trace Model, DTM)을 제안한다. 또한 제안된 DTM이 DPA 분석에 적합한가에 대해 이론적으로 증명하고 실험을 통해 검증한다. Differential Power Analysis is fully affected by various noises including temporal misalignment. Recently, Ryoo et al have introduced an efficient preprocessor method leading to improvements in DPA by removing the noise signals. This paper experimentally proves that the existing preprocessor method is not applied to all processor. To overcome this defect, we propose a Differential Trace Model(DTM). Also, we theoretically prove and experimentally confirm that the proposed DTM suites DPA.

반회후두신경 손상을 동반하지 않은 갑상선 절제술 후 음성 변화

최지선,정종인,장민석,손영익,Choi, Jee-Sun,Jeong, Jong-In,Jang, Min-Seok,Son, Young-Ik 대한후두음성언어의학회 2010 대한후두음성언어의학회지 Vol.21 No.1

Background and Objectives : Transient minor voice changes after thyroidectomy are not infrequent complaints even in cases without any evidence of recurrent laryngeal nerve damage. However, clinical course, diagnosis and management of such voice changes are not fully understood. This study aimed to evaluate the clinical characteristics of minor voice changes after thyroidectomy. We also tried to assess the significance and feasibility of superior laryngeal nerve monitoring and to find out the optimal evaluation tools for such voice changes after thyroidectomy. Materials and Method : Nine adult patients who received total thyroidectomy without evidence of recurrent laryngeal nerve injury were enrolled for this prospective study. Voice evaluations were performed preoperatively and 3 months postoperatively ; acoustic analyses including voice range profile, aerodynamic study, stroboscopic evaluation and subjective voice assessment with questionnaires. The external branch of superior laryngeal nerve was monitored by nerve stimulator after ligation of superior thyroidal vessels. Results: Four of nine patients complained their voice change at 3 months after the surgery. Three of them reported complete recovery of their voice at 6 months after the surgery. Acoustic analysis revealed significant decrease in their phonatory range especially with high tone loss. Questionnaires related to singing was more sensitive than previously well-known "voice handicap index". Stimulation of the superior laryngeal nerve was feasible in most of the cases (94.4%), but it failed to show any correlation with minor voice changes after thyroidectomy. Conclusion : Minor voice changes were not rare events during the first 6 month after thyroidectomy. Decrease in phonatory range with high tone loss and therefore, discomfort in singing was the most common finding. Superior laryngeal monitoring was feasible but it was not a sensitive tool for the prediction of minor voice change after thyroidectomy.

경량골재 콘크리트의 일본 시공사례

최지선,하주형,나옥빈,한승철,Choi, Ji-Sun,Ha, Ju-Hyung,Na, Ok-Pin,Han, Seung-Chul 한국건설순환자원학회 2017 한국건설순환자원학회지 Vol.12 No.3

19세기 대수학 및 논리학 발달에서의 드모르간의 위상

최지선,박선용,김재홍,권석일,박교식,Choi, Ji-Sun,Park, Sun-Yong,Kim, Jae-Hong,Kwon, Seok-Il,Park, Kyo-Sik 한국수학사학회 2009 Journal for history of mathematics Vol.22 No.4

이 연구의 목적은 19세기 대수와 논리 분야에서 드모르간이 구체적으로 어떻게 기여했는지를 살펴보는 것이다. 19세기 대수 분야 발달과정에서 드모르간은, 산술에서 단순히 유추한 형태의 기호대수를 넘어서, 형식으로부터 구성하는 수학의 가능성을 인식하고 이를 명시적으로 나타내어 추상대수학으로 나아갈 수 있는 기초를 닦았다. 드모르간은 19세기 논리학 분야 발달과정에서 아리스토텔레스 논리학의 재구성자인 동시에 수학적 논리학의 창시자로 간주할 수 있다. 그의 연구로 논리학이 철학에서 분리되어 나와 수학과 더욱 긴밀하게 결합하게 되어 수학적 논리학이 하나의 독립적 학문으로 자리 잡게 되었다. 그의 연구 활동을 통하여 우리는 19세기 수학의 발달에서 대수학과 논리학이 현재의 상태로 진화하여 가는 모습을 좀 더 명확하게 알 수 있다. The purpose of this study is what exactly De Morgan contributed to abstract algebra and mathematical logic. He recognised the purely symbolic nature of algebra and was aware of the existence of algebras other than ordinary algebra. He madealgebra as a science by introducing the ordered field and made the base for abstract algebra. He was one of the reformer of classical mathematical logic. Looking into De Morgan's works, we made it clear that the developments of algebra and mathematical logic in 19C.

최승희와 안막의 예술적 상관관계에 관한 고찰

최지선(Choi, Ji-Sun),최현주(Choi, Hyun-Ju) 한국체육과학회 2020 한국체육과학회지 Vol.29 No.6

Choi Seung-hee, a talented performing artist, and her husband Ahn-mak were ignored as pro-Japanese colonialism artists, communist performing artists, and proletariat writers. However, they have been re-examined since their invocation ceremony held in 2003 at Anseong, the birthplace of Mr. Ahn. Especially earlier known as a communist writer, Mr. Ahn’s accomplishments as an art manger have been recently discovered, bringing new attention from the society. To examine the artistic relationship between them, this research visited Mr. Ahn’s birthplace village and investigated the history of Ahn family which turned out to have good literary traditions. Owing to the sophisticated planning and support from the husband, a faithful and excellent guardian behind the scene, Ms. Choi became a world-famous artist, despite the various difficulties in the 1930s. Ms. Choi and Mr. Ahn were good partners to each other, and the combination of her artistic values and his excellent planning made the successful world tour performance beyond the boundary of Japan. This paper also reexamined whether their artistic behaviors went against the sentiment of the Korean people in the context of that time. A new perspective on the artist Choi can reveal that she pioneered a new path in dance history during the transition from traditional to modern society. The accomplishments and legacies they created together should not be undervalued by the current ideological division and should be continuously reviewed through generations.

<전우치전>의 욕망 구현 방식과 서사적 의미

최지선(Choi, Jiseon) 돈암어문학회 2015 돈암어문학 Vol.28 No.-

본고는 신문관본 <전우치전>을 주텍스트로 삼아 전우치의 욕망 발현과 실천의 양상에 주목하여 이를 분석하였다. 전우치 서사는 삽화편집적인 구성 방식이기 때문에 삽화의 편집 양상과 작품의 주제 의식이 긴밀한 연관을 가진다. 신문관본 <전우치전>은 순환적 구성 방식으로 서사의 완결성을 높이는 특성을 보이는데 서두의 미숙한 자아가 결말에서는 성장한 자아상으로 변화한다는 점에서 성장소설적 성격을 보여주는 구성이기도 하다. 전우치는 욕망에 의해 움직이는 인물인데다 작품의 전반과 후반에서 그 도술 행각이 이질적이라 인물 형상 및 주제의식의 일관성이 미흡하다고 평가돼 왔는데 이러한 점 역시 욕망의 실행과 실패의 서사로 읽는다면 자연스럽게 일관적 의미가 도출될 수 있어 다른 이본에도 이를 부분적으로 확대 적용하는 것이 가능할 것이다. 또한 신문관본은 최남선이라는 개작자가 분명한 작품이기도 하다. 이는 이 작품이 혼란한 시대를 살아가던 지식인으로서의 최남선의 고민과 지향이 투영된 작품이라는 의미이기도 하다. 구한 말, 몰락해 가던 조선의 혼란스러운 상황과 부패하고 무질서한 사회에 대한 비판의식을 가진 최남선은 기존 한글 소설 독자들의 대부분을 차지한 대중들을 고려하여 기존의 전우치 소설을 개작 대상으로 삼아 부패하고 무능한 정치 현실을 이야기를 통해 비판할 뿐 아니라 이를 읽는 독자들의 민족 의식을 고취하고 새로운 사상의 제시를 꾀한 것이라 할 수 있다. 이러한 신문관본을 비롯한 활자본의 개작 방향은 민중 영웅이자 사회 비판적 성격이 강한 ‘전우치’의 형상을 이룩하는 데 큰 영향을 끼친 부분이기도 하다. This thesis analyzes the revelation of desire and the narration of Jeon Woochi Jeon issued by Shinmungwan. The most important thing is the narration of Jeon Woochi Jeon that consists of an episodical structure. Because this development is closely related to the thematic concepts. Jeon Woochi Jeon based on Shinmungwan edition is organized as not only cyclical structure but also the same formality in front and back, increasing story completion, which features a “Bildungsroman”. Jeon Woochi is motivated by his desire, and he performs taoist magic from the first part to the second in Jeon Woochi Jeon. However, this development is criticized because his activities cut off the thematic concepts and statements. Although a number of criticisms insist that Jeon Woochi Jeon should be equipped with consistency, if it being read as Jeon Woochi’s performance and failure of his desire, the descriptive representation on Jeon Woochi Jeon can be possibly consistent and cyclical. In addition, this narrative configuration can be partly extended to different versions. Shinmungwan edition is known as Choi Namseon’s adaptation, which means that Choi Namseon portrays an intellectual anguish and lament in 19C. His work reflects his struggle to criticize and reform the Joseon Dynasty. Choi Namseon intents to adapt Jeon-Woo-Chi’s story, considering the public who is interested in novels in Korean. He is willing to intense the spirit of national consciousness and suggest the new thoughts, criticizing the corrupt and incompetent government at the time in Jeon Woochi Jeon. Therefore, including Shinmungwan edition, the adaptation from the previous novels to the diverse printed books makes Jeon Woochi’s imagery which is an influential character as well as a folk hero.

희망복지지원단 통합사례관리사의 사례관리역량 자기평가지표개발 연구

최지선(Choi, Ji-Sun),민소영(Min, So-Young),엄태영(Um, Tae-Young) 한국사회복지행정학회 2015 한국사회복지행정학 Vol.17 No.3

TIMSS 2015 ‘수’ 영역 정답률 분석을 통한 수학과 교육과정 고찰

최지선(Choi, Ji Sun) 학습자중심교과교육학회 2019 학습자중심교과교육연구 Vol.19 No.11

이 연구의 목적은 TIMSS 2015 수학 성취도 ‘수’ 영역의 우리나라 학생들의 정답률을 분석함으로써 우리나라 수학과 교육과정의 개선점을 탐색하는 것이다. 본 연구의 목적을 달성하기 위한 구체적인 연구문제는 다음과 같다. 첫째, ‘수’ 영역 중 우리 나라 학생들의 정답률이 낮은 문항들은 어떤 특성을 갖는가? 둘째, 우리나라 학생들의 낮은 정답률의 원인 중에 교육과정 상의 원인이 있는가? 이를 위하여 TIMSS 2015의 8학년 ‘수’ 영역 문항의 정답률을 성취도 상위국들과 비교하여, 우리나라 학 생들의 정답률이 낮은 내용요소를 파악하고, 해당 내용요소를 다루는 교육과정의 방식을 분석하였다. ‘수’ 영역의 우리나라 학생들의 정답률을 분석한 결과에 따르면, 우리나라 학생들은 TIMSS 2015의 전체 순위에서는 매우 높은 수준의 성취도를 나타 냈지만, 어림, 자연수의 사칙연산에 내재된 대수의 아이디어, 소수를 10배, 100배, 1000배 혹은 1/10, 1/100, 1/1000 배할 때의 소수의 변화, 음수의 사칙연산, 일상생활에서 널리 사용되고 있는 백분율 계산 능력은 성취도 상위국들과 비교하여 상대적으로 낮은 것으로 나타났다. 그리고 낮은 정답률의 원인 중 교육과정의 원인이 있는 부분은 어림, 자연수의 사칙연산에 내재된 대수의 아이디어, 소수의 변화임을 분석하였다. 마지막으로 이러한 결과를 바탕으로 교육과정 개정에 대한 시사점을 도출하였다. The aim of this study was to identify whether the low percentage of correct answers of Korean students would relate to Korea national math curriculum or not by analyzing Korean students’ mathematics achievement in TIMSS 2015 eighth grade test ‘Number’ domain. Concretely, this study analyzed the percentage of correct answers of 64 items that belong to TIMSS 2015 ‘Number’ domain and identified 10 items that the percentage of correct answers of Korean students are lower than that of 11 countries which were the highest achievements(Singapore, Republic of Korea, Chinese Taipei, Hong Kong SAR, Japan, Russia Federation, Kazakhstan, Canada, Ireland, United States, England). And this study analyzed seventh math curriculum. 2007 revised math curriculum, 2015 revised math curriculum and 2015 revised math curriculum to investigate whether there is a relation between the low achievements of items and Korea national math curriculum. As a results, Korean students had low achievements in estimation, the properties of whole number operation(commutativity, associativity, distributivity), the relation between decimal numbers by multiplying or dividing 10, 100, 100 and so on, the operation of negative numbers, solving problems of percentage. This study found the relation between the low achievements and Korea national math curriculum in computational estimation, the properties of whole number operation, the relation between decimal numbers by multiplying or dividing. We discussed the some issues of math curriculums and suggest the direction of revision of math curriculums.

항만공항기술연구소

최지선(Jisun Choi),Yuichiro KAWABATA 한국콘크리트학회 2014 콘크리트학회지 Vol.26 No.4