단열 페인트 첨가제로써 중공형 실리카 나노입자의 크기에 따른 효과

김지수,김영훈,Kim, Jisue,Kim, Younghun 한국청정기술학회 2022 청정기술 Vol.28 No.1

에너지 절약을 위한 연구 중 단열 기술 분야에서는 공기의 낮은 열전도도를 활용한 연구가 이뤄지고 있으며 널리 상용화 되고 있다. 본 연구에서는 입자 내부에 공기층을 갖는 중공형(hollow) 형태의 실리카 나노 입자를 제조하여 공기층 크기가 단열 성능에 미치는 영향에 대해 고찰하였다. Polystyrene 주형법을 이용하여 졸-겔공정을 통해 속이 빈 중공형 실리카 나노 입자(Hollow silica nanoparticles)를 제조하였고, 입자를 5 wt %로 도료에 첨가한 후 열전달 실험을 통해 단열 성능을 확인하였다. 기존 페인트에 입자를 혼합하여 약 15 %이상의 단열효율을 나타냈으며, 내부 공기층의 크기가 큰 입자가 작은 입자에 비해 5% 높은 단열 성능을 나타냈다. 이번 연구를 통해 내부 크기에 따른 단열효과의 차이를 보여줌으로써, 중공형 형태의 입자를 첨가제나 도료 제조에 사용하는 경우 단열효과를 높이기 위해 매질 내에서 입자가 공기층을 최대로 이룰 수 있도록 입자의 크기를 고려해야함을 제시한다.

SWAT model과 기후변화 자료를 이용한 산사태 예측 기법 제안과 평가: 지리산 국립공원 중산리 일대 사례연구

김지수,김민석,조용찬,오현주,이춘오,Kim, Jisu,Kim, Minseok,Cho, Youngchan,Oh, Hyunjoo,Lee, Choonoh 한국지하수토양환경학회 2021 지하수토양환경 Vol.26 No.6

The purpose of this study is prediction of landslide occurrence reflecting the subsurface flow characteristics within the soil layer in the future due to climate change in a large scale watershed. To do this, we considered the infinite slope stability theory to evaluate the landslide occurrence with predicted soil moisture content by SWAT model based on monitored data (rainfall-soil moisture-discharge). The correlation between the SWAT model and the monitoring data was performed using the coefficient of determination (R²) and the model's efficiency index (Nash and Sutcliffe model efficiency; NSE) and, an accuracy analysis of landslide prediction was performed using auROC (area under Receiver Operating Curve) analysis. In results comparing with the calculated discharge-soil moisture content by SWAT model vs. actual observation data, R² was 0.9 and NSE was 0.91 in discharge and, R² was 0.7 and NSE was 0.79 in soil moisture, respectively. As a result of performing infinite slope stability analysis in the area where landslides occurred in the past based on simulated data (SWAT analysis result of 0.7~0.8), AuROC showed 0.98, indicating that the suggested prediction method was resonable. Based on this, as a result of predicting the characteristics of landslide occurrence by 2050 using climate change scenario (RCP 8.5) data, it was calculated that four landslides could occur with a soil moisture content of more than 75% and rainfall over 250 mm/day during simulation. Although this study needs to be evaluated in various regions because of a case study, it was possible to determine the possibility of prediction through modeling of subsurface flow mechanism, one of the most important attributes in landslide occurrence.

SWAT 모델을 이용한 강우특성 변화에 의한 퇴적물-유출량 간의 관계 평가

김지수,김민석,조용찬,Kim, Jisu,Kim, Minseok,Cho, Youngchan 한국지하수토양환경학회 2021 지하수토양환경 Vol.26 No.6

The sediment transportation caused by soil erosion due to rainfall-discharge in the large watershed scale plays critical role in human society. The relationship between rainfall-discharge-sediment transportation is depending on the start time of rainfall and end of rainfall but, the studies related with rainfall characteristics are insufficient. In this study, The Soil and Water Assession Tool (SWAT) model was used to study the relationship between rainfall-discharge-sediment transportation at the Sook river watershed which is monitored by the Ministry of Environment. To do this, first of all, the sensitivity analysis about model attributes was performed using monitored data. The accuracy analysis of SWAT model was conducted using the model's efficiency index (Nash and Sutcliffe model efficiency; NSE) and the coefficient of determination (R²). After that, it was studied what results could be obtained according to changes in rainfall timing and end points. In the result of discharge simulation, the modified rainfall values (sum of total rainfall starting time and end time) showed more high accuracy values (R²:0.90, NSE: 0.8) than original rainfall values (R²:0.76, NSE: 0.72). In the result of sediment transportation simulation, during calibration had more resonable results(R²:0.87, NSE: 0.86) than compared with original rainfall values (R²:0.44, NSE: 0.41). However, validation results of sediment transportation simulation showed low accuracy values compared with calibration results. This results maybe cause monitoring periods of sediment flow compared with discharge monitoring periods. Nevertheless, since rainfall characteristic plays critical rule in model results, continuous research on rainfall characteristic is needed.

한복과 한푸의 차이점 분석에 관한 연구

김지수,나영주,Kim, Jisu,Na, Youngjoo 대한가정학회 2022 Human Ecology Research(HER) Vol.60 No.2

(K)Hanbok, which is Korea's traditional clothing, differs from the Chinese Hanfu or Japanese Kimono. This study aims to understand the fundamental differences between (K)Hanbok and Hanfu. The Goryeo Dynasty (K)Hanbok, which was particularly popular in China, was established because the Ming Dynasty Hanfu and Chinese fashion were considerably influenced by the 'Koryo Yang'. Firstly, while (K)Hanbok is bulky, Hanfu of the Han Dynasty is characterized by forming a slim silhouette. Due to the climate of the Northern Hemisphere, (K)Hanbok shows a rich silhouette comprising multiple layers of inner pants and a pleated skirt over a voluminous underskirt. On the other hand, the Han's Hanfu creates a straight silhouette in the form of a wrap, revealing the contours of the body. The pleated skirt of the (K)Hanbok can use six to twelve width fabrics, depending on the social position; however, the Hanfu of the Han is a skirt without any pleats. Secondly, the clothing patterns, which have various shapes, are totally different in how they are made and sewn. The Korean (K)Hanbok is a two-piece separate, whereas the Chinese Hanfu style is a one-piece with a skirt. The short length of the (K)Hanbok jacket has a Sup which is cut and pasted allowing the front closure to overlap. Nevertheless, the Hanfu of the Han does not have this Sup because it is of a wrap-around, one-piece style and has an exceptionally large front, and wraps around at the waist which extends to the sides. Thirdly, the (K)Hanbok jacket has separate string Gorums for fastening, and an additional belt around the waist; however, in the case of Gorum, it is unnecessary for a wrapping style of Hanfu. Fourthly, Koreans as an agricultural horse-riding people, basically wore the trousers attached a comfortable gusset, while the Chinese Hanfu had no pants, but the Chinese wore Gaedanggo pants which exposed the hips, inevitably during the Warring States period.

패션 인스타그램 해시태그가 소비자 태도에 미치는 영향

김지수,정다은,조민주,나영주,Kim, Jisu,Jeong, Da Eun,Jo, Minjoo,Na, Youngjoo 한국섬유공학회 2018 한국섬유공학회지 Vol.55 No.2

Recently, the number of Instagram users is increasing and the marketing strategy of fashion brands to utilize hashtags (#) is rapidly growing. This study investigates the effects of hashtags in fashion-Instagram on consumer attitudes. The purpose of this study is to investigate the effect of the number, language, and relevance of the hashtags used in fashion-Instagram on the cognitive, emotional, and behavioral factors of consumer attitudes. The results of this study are as follows: First, a lesser number of hashtags has a positive effect on these factors. Second, when the language of the hashtag is English rather than Korean, it has a positive effect on the abovementioned factors. Third, when there is a relationship between the hashtag and the post, the consumers showed significantly more positive attitudes. Therefore, this study can help fashion brands to more effectively utilize hashtags in marketing using Instagram. In addition, this study will likely lead to the development of methods for utilizing hashtags as a more specific means of marketing through future studies.

LED 등기구에 사용되는 도광판 패턴에 따른 광특성 분석 연구

김지수(Jisu Kim),김해규(Haegyu Kim),김재연(Jaeyeon Kim),유소영(Soyoung You),강수빈(Subeen Kang),백운회(Woonhoi Baek),김진선(Jinsheon Kim) 한국조명·전기설비학회 2023 한국조명·전기설비학회 학술대회논문집 Vol.2023 No.11

파트 기반 모델을 이용한 자동차 검출 시스템 개발

김지수(Jisu Kim),백정현(Jeonghyun Baek),현준혁(Junhyuk Hyun),김은태(Euntai Kim) 대한전기학회 2015 정보 및 제어 심포지엄 논문집 Vol.2015 No.4

스마트 폰 기반 영상처리 기법을 활용한 간편 부피계측 및 계량 어플리케이션

김지수(Jisu Kim),박근주(Geunjoo Park),안수빈(Subin An),현정원(Jungwon Hyun),박승수(Seungsoo Park),이중재(Joongjae Lee) 한국통신학회 2016 한국통신학회 학술대회논문집 Vol.2016 No.11

긍정적 행동지원 실행에 참여한 전문가들의 경험과 인식에 관한 질적 연구

김지수 ( Jisu Kim ),김예리 ( Ye Ri Kim ),박지연 ( Jiyeon Park ) 한국정서·행동장애아교육학회(구 한국정서학습장애아교육학회) 2015 정서ㆍ행동장애연구 Vol.31 No.4

본 연구는 S시 교육청의 주도로 실행된 개별차원의 긍정적 행동지원에 참여한 전문가들의 경험과 인식을 고찰하고자 실시되었다. 본 연구의 참여자는 2012년부터 시작된 S시 교육청의 긍정적 행동지원단 사업에 1년 이상 참여한 9명의 특수교육 전문가와 2명의 사회복지사로, 총 11명이다. 이들을 대상으로 개별면담을 실시하였고, 모든 면담은 전사한 후 지속적 비교법을 사용하여 분석하였다. 질적 분석 결과 4가지 대주제와 24가지 하위주제가 도출되었으며, 도출된 대주제는 다음과 같다: (ㄱ) 역할, (ㄴ) 고충, (ㄷ) 보람과 성장, (ㄹ) 건의. 논의에서는 각 주제별 시사점과 주제들 간의 유기적 관계를 논의하고, 연구의 제한점을 제시하였다. 본 연구는 교육청 주도의 긍정적 행동지원 노력에 참여한 전문가들의 경험과 인식을 심층적으로 고찰함으로써, 향후 장애학생의 행동지원 관련 연구와 정책이 나아가야 할 방향을 제시했다는 데 그 의의가 있다. This study was conducted to investigate the experiences and perceptions of eleven professionals who participated in the positive behavior support (PBS) project, which has been initiated and maintained since 2012 by S city Office of Education in Korea. The participants were nine special education experts and two social workers who were involved in the project for at least 1 year. Individual interviews were conducted with each participant and all interviews were transcribed verbatim. The transcripts were coded and analyzed using the constant comparative method. Four main themes identified from the analysis are as follows: (a) roles, (b) difficulties and dilemmas, (c) outcomes and personal growth, and (d) suggestions for future PBS implementation. Finally, the implications of the results were discussed and the limitations of the study were presented. This study contributed to the field in that it suggested the directions for future research and policy through investigating the perceptions and experiences of those who were involved in the positive behavior support efforts.

적응 제어를 이용하여 그래프 연결성을 배제시킨 선형 다개체 시스템의 상태변수 일치 알고리듬

김지수(Jisu Kim),김홍근(Hongkeun Kim),심형보(Hyungbo Shim),백주훈(Juhoon Back) 제어로봇시스템학회 2012 제어·로봇·시스템학회 논문지 Vol.18 No.7

This paper studies asymptotic consensus problem for linear multi-agent systems. We propose a distributed state feedback control algorithm for solving the problem under fixed and undirected network communication. In contrast with the conventional algorithms that use global information (e.g., graph connectivity), the proposed algorithm only uses local information from neighbors. The principle for achieving asymptotic consensus is that, for each agent, a distributed update law gradually increases the coupling gain of LQR-type feedback and thus, the overall stability of the multi-agent system is recovered by the gain margin of LQR.