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 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.

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.

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.

Phlojodicarpus sibiricus와 Artemisia kruhsiana Besser 추출물의 항림프종 효과 분석

김지수(Jisu Kim),김동욱(Dong Uk Kim),남제현(Jehyun Nam),전별은(Byeol Eun Jeon),재나 오클롭코바(Zhanna M. Okhlopkova),이스마일 줄푸가로프(Ismayil S. Zulfugarov),김상우(Sang-Woo Kim) 한국생명과학회 2020 생명과학회지 Vol.30 No.4

Phlojodicarpus sibiricus와 Artemisia kruhsiana Besser는 러시아 극한 지방에서 자생하며, 민간요법으로 널리 쓰여왔다. 최근 연구에 따르면, 두 식물 추출액(PSE와 AKBE)은 항비만효과, 혈관신생 억제 효과 등 다양한 의학적 효과를 가진 것으로 나타났다. 본 연구논문에서는 PSE와 AKBE의 항림프종 효과와 기작을 분석하였다. PSE와 AKBE를 다양한 유전적 변이를 가진 DLBCL 세포주에 처리하였을 때, 농도 의존적으로 세포 생존율이 감소하였다. 하지만, 마우스의 골수나 비장으로부터 분리한 정상 세포에는 거의 영향을 미치지 않는 것으로 보아, 두 식물 추출액의 세포사멸 효과는 종양세포 특이적인 것으로 예상되며, 환자에 적용할 경우 부작용이 최소한만 나타날 것으로 예상된다. PSE와 AKBE의 세포사멸 효과는 Bcl-2, Bcl-xL, 그리고 Mcl-1 등의 anti-apoptotic Bcl-2 family member 유전자의 감소로 인한 미토콘드리아의 막 전위 붕괴에 기인함을 증명하였다. 흥미롭게도, 두 식물 추출액에 의한 세포사멸 효과는 Myc 종양유전자와는 독립적으로 일어났다. 이 결과를 종합하면, PSE와 AKBE는 항림프종 효과를 보유하고 있으며, 추후 연구를 통하여 세포사멸에 관여하는 단일 물질을 분리할 경우, 기존의 항암제를 대체할 수 있는 새로운 방법을 제시할 수 있을 것으로 기대된다. Phlojodicarpus sibiricus and Artemisia kruhsiana Besser are medicinal plants traditionally used in Russia. Phlojodicarpus sibiricus extracts (PSE) have been shown to have anti-obesity properties, and Artemisia kruhsiana Besser extracts (AKBE) contain terpenoid compounds that exert various medicinal effects. Here, we investigated the potential pro-apoptotic effects of PSE and AKBE in diffuse large B-cell lymphoma (DLBCL) and elucidated the underlying mechanism. PSE and AKBE treatment of six DLBCL cell lines with various genetic abnormalities effectively reduced cell viability in a dose-dependent manner, while having a minimal impact on the survival of normal murine bone marrow cells and splenocytes. This suggests that the cytotoxic effects of PSE and AKBE are specific to DLBCL cells. Therefore, we expect limited side effects when these plant extracts are administered to DLBCL patients. Our JC-1 assays demonstrate that the pro-apoptotic effects of these plant extracts are produced by a reduction of anti-apoptotic Bcl-2 family members and, thereby, disruption of the mitochondrial membrane potential. Moreover, PSE and AKBE induce cell death independently of Myc, whose abnormalities are frequently observed in patients with DLBCL and are associated with poor prognosis. Our findings reveal hitherto uncharacterized pro-apoptotic effects of PSE and AKBE in DLBCL. Isolation of single compounds with anti-lymphoma activities should be pursued further.

버추얼 프로덕션 (Virtual Production)을 활용한 퍼포먼스 영상 작품 제작 연구: 댄스필름 ‘Not at Home’ 제작 사례를 중심으로

김지수(Jisu Kim),김휘성(Wheesung Kim),윤수련(Sooryun Yoon),한단비내린(Danbinaerin Han),최용순(Yongsoon Choi) 한국HCI학회 2023 한국HCI학회 학술대회 Vol.2023 No.2

실감형 국악 공연 콘텐츠 제작 사례 연구

김지수(Jisu Kim),정수경(Su-kyung Jeong),장석현(Seok-hyeon Jang),김민정(Minjeong Kim),유현식(Hyunsik Yoo) 한국HCI학회 2020 한국HCI학회 학술대회 Vol.2020 No.2

본 논문은 "실감형 국악 공연 콘텐츠의 제작 연구를 진행한 사례이다. 콘텐츠의 제작 과정에서 얻게된 방법과 한계점을 분석했다. 연구를 통해 제작한 콘텐츠는 흔히 제작되는 앨범의 방식에서 벗어나 VR(Virtual Reality)앨범의 형태를 지니고 있다. 본 콘텐츠는 360 영상 촬영과 동시에 입체음향 녹음을 진행하였고 실재감을 높여 체험자가 실제 현장에서 공연을 보는듯한 몰입도를 제공했다.

동일한 전달 행렬을 가지는 안정화 가능한 이종 시스템들의 출력 일치

김지수(Jisu Kim),김홍근(Hongkeun Kim),심형보(Hyungbo Shim),백주훈(Juhoon Back) 제어로봇시스템학회 2011 제어·로봇·시스템학회 논문지 Vol.17 No.9

This paper studies the output consensus problem for a class of heterogeneous linear multi-agent systems under a fixed directed communication network. The dynamics, as well as its dimension, of each agent can widely differ from the others, but all the agents are assumed to have the same transfer matrix. In addition, only the system outputs are constrained to be delivered through the network. Under these conditions, we show that the output consensus is reached by a group of identical controllers, which is designed to achieve the state consensus for the homogeneous multi-agent system obtained from the minimal realization of the transfer matrix. Finally, an example is given to demonstrate the proposed result.

APAN에서의 ECTP Testbed 구축 및 응용 실험

김지수(Jisu Kim),박주영(Juyoung Park),김대영(Dae Young Kim),강신각(Singak Kang) 한국통신학회 2003 한국통신학회 학술대회논문집 Vol.2003 No.11