백서 상복부 혈관의 동결시간에 따른 변화에 대한 연구

김우찬,이종헌,김경욱,김창진,Kim, Woo-Chan,Lee, Chong-Heon,Kim, Kyung-Wook,Kim, Chang-Jin 대한악안면성형재건외과학회 1999 Maxillofacial Plastic Reconstructive Surgery Vol.21 No.2

Vascular spasm which has been reported to occur in 25% of clinical cases continues to be a problem in microvascular surgery; When prolonged and not corrected, it can lead to low flow, thrombosis, and replant or free flap failure. Ischemia, intimal damage, acidosis and hypovolemia have been implicated as contributors to the vascular spasm. Although much work has been done on the etiology and prevention of vasospasm, a spasmolytic agent capable of firmly protecting against or reversing vasospasm has not been found. Therefore vascular freezing was introduced as a new safe method that immediately and permanently relieves the vasospasm and can be applied to microsurgical transfers. Cryosurgery can be defined as the deliberate destruction of diseased tissue or relief the vascular spasm in microvascular surgery by freezing in a controlled manner. 96 Sprague Dawley rats each weighing within 250g were used and divided into 2 group, experimental 1 and 2 group. In the experimental 1 group, right epigastric vessels (artery and vein) were freezed with a cryoprobe using $N_2O$ gas for 1 min. In the experimental 2 group, after freezing for 1 min, thawing for 30 secs and repeat freezing for 30 secs. Left side was chosen as control group in both group. We sacrified the experimental animals by 1 day, 3 days, 1 week, 2 weeks, 4 weeks & 5 months and observed the sequential change that occur during regeneration of epigastric vessels using a histologic, histomorphometric, immunohistochemical and SEM study after the vascular freezing. The results were as follows1. In epigastric arteries, internal diameters had statistically significant enlargement in 1 day, 3 days of Exp-1 group and 1 day, 3 days, 1 week & 2 weeks of Exp-2 group. Wall thickness had statistically significant thinning in 2 weeks of Exp-2 group. 2. In epigastric veins, internal diameters had enlargement of statistical significance in 1 day of Exp-1 and Exp-2 group. 3. The positive PCNA reactions in smooth muscle appeared in 1 week and increased until 2 weeks, decreased in 4 weeks. There was no statistical significance between Exp-1 and Exp-2 group. 4. The positive ${\alpha}$-SMA reaction in smooth muscles showed weak responses until 1 week and slowly increased in 2 weeks and showed almost control level in 4 weeks. 5. The positive S-100 reactions in the perivascular nerve bundles showed markedly decrease in 1 day, 3 days and increased after 1 week and showed almost control level in 4 weeks. Exp-1 group had stronger response than Exp-2 group. 6. In SEM, we observed defoliation of endothelial cell and flattening of vessel wall. Exp-2 group is more destroyed and healing was slower than Exp-1 group. To sum up, relief of vasospasm (vasodilatation) by freezing with cryoprobe was originated from the damage of smooth muscle layer and perivascular nerve bundle and the enlargement of internal diameter in vessels was similar to expeimental groups, but Exp-2 group had slower healing course and therefore vessel freezing in microsurgery can be clinically used, but repeat freezing time needs to be studied further.

기관지협착환자에서 기관지내 팽창성 급속 스텐트 삽입후 재발한 기관지협착 치험 2례

김우찬,진웅,나석주,조건현,이선희,곽문섭,김세화,Kim, Woo-Chan,Jin, Ung,Rha, Suk-Joo,Jo, Keon-Hyon,Lee, Sun-Hee,Kwack, Moon-Sub,Kim, Se-Wha 대한흉부심장혈관외과학회 1995 Journal of Chest Surgery (J Chest Surg) Vol.28 No.5

Since the insertion of self expandable metalic stent[SEMS has became popular method for hollow organ stenosis, many attempts for further apply the stent to airway stenosis as an simple procedure has been made, but intrabronchial migration of stent or occurrence of inflammatory granuloma around stent develop occasionally and sometimes it worsen bronchial stenosis further more. This report describes 2 case of surgically treated bronchial restenosis in whom intrabronchial stent were applied for release of bronchial stenosis. Our surgical option was pneumonectomy and bronchoplasty with sleeve right middle and upper lobectomy respectively. During the operation we found the SEMSs were tightly impacted in restenotic bronchial lumen with overgrowth of granulation tissues. The bronchial obstructions occupied more than 90% of lumens in both cases, and needed much complicated procedure to be relieved. Therefore, even though the insertion of SEMS remains as a prcedure determined by the physician`s preference, it has to be considered prudently that the use of SEMS can cause severe restenosis and the surgeon has more difficulties in performing segmental resection of restenotic bronchus in patient with SEMS previously inserted. Throughout these experiences we can conclude that the insertion of SEMS must be performed only in very selected cases of bronchial stenosis.

위치 측정을 위한 비콘의 RSSI 안정화

김우찬(Woo-Chan Kim),이청길(Cherng-Ghill Lee),곽호영(Ho-Young Kwak) 한국컴퓨터정보학회 2019 한국컴퓨터정보학회 학술발표논문집 Vol.27 No.1

The Companion Animal Monitoring System using Low-Power Protocol Wearable Device

Woo-Chan Kim(김우찬),Soo Kyun Kim(김수균),Ho-Young Kwak(곽호영) 한국컴퓨터정보학회 2020 韓國컴퓨터情報學會論文誌 Vol.25 No.12

반려 동물을 키우는 가구가 늘어나면서 원격지에서 반려동물의 상태를 파악하려는 수요가 늘어나고 있다. 우리는 웨어러블 디바이스를 반려동물에게 착용시켜서 심박신호를 원격지에서 모니터링 할 수 있는 것을 목표로 한다. 그러나 블루투스를 이용한 모니터링 방식은 근거리에서만 접속할 수 있는 단점이 있고, WiFi를 통해 받아보는 방식은 전력 소모량이 크다는 단점이 있다. 이 문제를 해결하기 위해서 사용자가 필요로 하지 않는 시점에는 블루투스를 이용하여 사용자의 요청을 간접적으로 받고, 사용자가 모니터링 요청을 한 경우 WiFi를 통해 센서 데이터를 보내는 방식으로 전력 소비량을 줄이는 시스템을 제안한다. As the number of households with companion animals increases, the demand to monitor the health of companion animals in remote locations far away is increasing. We are going to put a wearable device on a companion animal so that it can monitor the heart beat signal from a remote location. However, the monitoring method using Bluetooth has some disadvantages. it can be accessed only in a short distances. In case of WiFi, large power consumption is the problem. To overcome these issues, we propose a system to reduce power consumption by indirectly receiving a user"s request using Bluetooth at a time when the user does not need it, and sending sensor data through WiFi when the user makes a monitoring request.

수동센서를 이용한 효율적인 표적추적을 위한 적응적 자원관리 알고리듬 연구

김우찬(Woo Chan Kim),이해호(Haeho Lee),안명환(Myonghwan Ahn),이범직(Bum Jik Lee),송택렬(Taek Lyul Song) 제어로봇시스템학회 2016 제어·로봇·시스템학회 논문지 Vol.22 No.7

To enhance tracking efficiency, a target-tracking filter with a resource management algorithm is required. One of the resource management algorithms chooses or evaluates the proper sampling time using cost functions which are related to the target tracking filter. We propose a resource management algorithm for bearing only tracking environments. Since the tracking performance depends on the system observability, the bearing-only tracking is one of challenging target-tracking fields. The proposed algorithm provides the adaptive sampling time using the variation rate of the error covariance matrix from the target-tracking filter. The simulation verifies the efficiency performance of the proposed algorithm.

GMM-TS를 이용한 표적기동분석용 배치구간 및 초기상태 추정 기법

김우찬(Woo-Chan Kim),송택렬(Taek-Lyul Song) 제어로봇시스템학회 2012 제어·로봇·시스템학회 논문지 Vol.18 No.3

Using bearing measurement only, target motion state is not directly obtained so that TMA (Target Motion Analysis) is needed for this situation. TMA is a nonlinear estimation technique used in passive SONAR systems. Also it is the one of important techniques for underwater combat management systems. TMA can be divided to two parts: batch estimation and sequential estimation. It is preferable to use sequential estimation for reducing computational load as well as adaptively to target maneuvers, batch estimation is still required to attain target initial state vector for convergence of sequential estimation. Selection of batch time interval which depends on observability is critical in TMA performance. Batch estimation in general utilizes predetermined batch time interval. In this paper, we propose a new method called the BTIS (Batch Time Interval and Initial State Estimation). The proposed BTIS estimates target initial status and determines the batch time interval sequentially by using a bank of GMM-TS (Gaussian Mixture Measurement-Track Splitting) filters. The performance of the proposal method is verified by a Monte Carlo simulation study.

부모가 자녀의 TV시청시간에 미치는 영향

김우찬(Kim Woo-Chan),이윤석(Lee Yun-Suk) 한국청소년정책연구원 2009 한국청소년연구 Vol.20 No.1

TV시청행위는 대부분의 산업국가 10대 청소년들에게 보편적인 여가행위이다. 텔레비전은 청소년들에게 역기능과 순기능을 동시에 한다. 이러한 TV시청시간에 부모의 사회경제적 지위와 TV시청행위는 큰 영향을 준다고 한다. 그러나 이전 연구는 일부 연령대나 특정 지역의 청소년만을 대상으로 하였다. 또한 왜곡 가능성이 높은 직접 보고(self-report) 방식으로 모은 자료를 분석하였다. 이러한 문제점을 해소하기 위해 본 연구는 통계청이 2004년 실시한 생활시간자료를 분석하여 부모의 사회경제적 지위와 TV시청시간이 10대 청소년의 TV시청시간에 미치는 영향을 분석한다. 분석 결과, 부모의 사회경제적 지위가 낮을수록 그리고 부모의 TV시청시간이 많을수록 자녀의 TV시청시간이 증가하는 것으로 나타났다. 또한 분석 결과는 자녀양육에 있어 아버지와 어머니의 역할 차이가 있음을 암시한다. 어머니가 자녀의 사회화 과정에 직접적으로 개입하는데 비해 아버지는 자녀에게 경제적 자원을 제공하는 역할을 주로 맡는다. Most children watch TV in industrialized countries. Watching TV may have bothdetrimental and beneficial effects upon teenagers. A great deal of research has been done to examine the factors which potentially affect children's TV watching time and have concluded that parental socioeconomic status and TV watching time are very significant. However, previous studies are methodologically flawed in that (1) they focus on only limited age ranges of children from certain areas or (2) they examine self-reported data that are often biased. Using the data from a sample of 3,816 teenagers of the 2004 National Time Use Study, this study attempts to test whether parental socioeconomic status and TV watching time influence children's TV watching time. We find that the higher parental socioeconomic status is, the less time their children spend watching TV. Moreover, the more time parents spend watching TV themselves, the more time their children also spend watching TV. Ourresults imply that there is division of labor in children-rearing between mothers and fathers. It seems that mothers are directly involved in children's socialization while fathers may provide their children with some economic stability and resources.

결혼이주여성의 서비스 이용실태 및 가족관계에 관한 연구

김우찬(Kim, Woo-Chan) 한국복지행정학회 2015 복지행정논총 Vol.25 No.1

본 연구는 결혼이주여성들의 서비스 이용실태 및 가족관계 정도를 알아보고, 결혼이주여성들의 안정된 한국생활의 정착과 가족관계의 향상을 위한 개입방안을 모색하는데 궁극적인 목적이 있다. 이러한 목적을 달성하기 위하여 결혼이주여성 152명을 대상으로 조사ㆍ분석한 결과는 다음과 같다. 첫째, 결혼이주여성의 평균연령은 32세였으며, 학력은 고등학교 졸업인 경우가 가장 많았고, 언어구사능력 정도는 중간 정도였다. 결혼동기는 한국인 남편이 좋아서, 한국에서 살고 싶어서가 많았고, 결혼경로는 아는 사람의 소개와 국제결혼중개업체를 통해서가 많이 나타났으며, 생활상의 어려움 정도는 자녀교육문제, 소득문제, 직업문제, 자녀보육문제 순으로 높았다. 둘째, 결혼이주여성은 한국어교실을 가장 많이 이용하고 있는 것으로 나타났으며, 사회복지서비스 욕구에서는 한글교육 및 통역, 건강검진, 일자리알선 욕구가 높았다. 셋째, 결혼이주여성의 자녀와의 관계와 남편과의 관계는 만족하는 수준으로 나타났다. 이상의 연구결과를 토대로 몇 가지 개입방안을 제시하였다. This study tries to understand the service usage of international marriage migrant women and their relationship with their family and to seek better ways for them to settle in Korea and to improve their family relations. In order to achieve this objective, 152 migrant women were surveyed. The results are as follows. First, the average age of international marriage migrant women was 32 years old, high school was the highest level of schooling for most of them, and their command of Korean language was roughly moderate. The average number of families of these women was 4.13 while majority of them lived with their spouses and children and some of them lived with their parents in law. The average monthly income was 1.51 million wons and most of their houses were owned. The reason of marriage was because they liked their Korean husband and to live in Korea. Most of them were introduced to their spouses through acquaintance or marriage brokerage companies and the majority of them were unemployed. Child education was their biggest financial difficulty followed by income, profession, child care, in order. Second, the average level of satisfactory in their relationship with their children was 1.76, and 3.05 with their husbands. The level of satisfactory was different among different level of language skills and monthly income while age, income, and motivation of marriage indicated significant difference in the level of satisfaction in their relationship with their husbands. Measures that can be provided to better serve them live in Korean society and to increase their family relationships are as follows. First, the intervention should be on the entire family rather than an individual. Second, the migrant women should be given diverse programs which will facilitate them to adapt to Korean life. Third, spouse counseling as well as family counseling should be provided in order to overcome cultural differences. Fourth, measures should be provided to solve their financial difficulties and to ensure the rights of international marriage migrant women. Fifth, the Korean society should change their perceptions against these women.

시각장애인의 의류 색상 인지를 위한 색상의 명도 및 채도와 촉감 재질감의 연관성 탐구

김우찬 ( Kim¸ Woo Chan ),조준동 ( Cho¸ Jun Dong ),이상원 ( Lee¸ Sangwon ) 디자인융복합학회(구.한국인포디자인학회) 2020 디자인융복합연구 Vol.19 No.6

본 연구의 색과 촉감의 매칭 시스템 디자인은 재질의 질감으로 색 정보를 연상시키고자 한 것으로, 시각장애인들의 의류 구매 활동 시 색에 대한 정보를 촉감을 통해 인지할 수 있도록 하는 데 목적이 있다. 색과 촉감의 관계에 관한 선행 연구를 바탕으로 고안된 시스템의 원리는 색의 3요소 중 채도와 명도를 질감의 거칠기와 부드러움으로 매칭하여 촉감을 통해 색을 인지할 수 있도록 디자인하였다. 채도는 거칠기에 비례하고 명도는 부드러움에 비례한다는 연구결과를 바탕으로 색상 레벨에 맞는 질감을 일대일 대응하여 총 3가지를 옷의 태그에 부착한 프로토타입을 제작하였다. 질감을 선정하기 위해 3명의 시각장애인을 대상으로 파일럿 실험을 진행하였다. 그리고 시각장애인 4명, 정안인 6명을 포함해, 총 10명을 대상으로 프로토타입을 활용한 실험에서 효용성 평가를 진행하였다. 실험 결과, 대부분의 연구대상자가 색을 인지할 수 있었고, 효용성 평가에서도 10명 중 4명에게서 유의미한 결과를 얻었고, 2명에게서 약간의 유의미한 결과를 얻었다. 이러한 결과를 토대로 이 시스템을 활용하면 의류 구매 활동에서 시각장애인들의 능동적인 경험을 유도할 수 있고 더불어 삶의 질을 향상하고 행복추구권을 높이는데 함의가 있다. This study is designed for the visually impaired to recognize color information through the texture of materials when purchasing clothing. The principle of the system design is to apply one on one mapping between two elements of color (saturation, value) with two elements of texture (roughness, softness). Base on research finding that the chroma is proportional to the roughness and the value is proportional to the softness, a total of three prototypes attached to tags on clothes were produced in one-to-one correspondence to textures that fit color levels. Three visually impaired people tested to select textures and 10 people, including 4 who are visually impaired and 6 who are normal people, were evaluated for usability of color and tactile matching through system usability scale. The result showed that most of the subjects were able to recognize the color and significant results were obtained from 4 out of 10 people in the system usability scale, and marginally significant results were obtained from 2 people. Based on these result, this system can be used to induce active experiences of the visually impaired in clothing purchasing activities, as well as to improve the quality of life and increase the right to pursue happiness.

UWB 통신 시스템용 마이크로스트립 안테나 설계 및 구현

김우찬(Woo Chan Kim),차이링즈(Cai ling zhi),양철용(Cheol Yong Yang),이성하(Seong Ha Lee),양운근(Woon Geun Yang) 한국통신학회 2011 한국통신학회 학술대회논문집 Vol.2011 No.6