兩面이 볼록한 物體周邊에 形成된 非壓縮性 層流 境界層內의 剝離現象에 관한 數値解析的 硏究

朴伊東,鄭雲哲 成均館大學校 1982 論文集 Vol.32 No.-

The object of this study was to find the separation point through Numerical Method, which happened at lower surface in a two dimensional incompressible laminar boundary layer formed around symmetrical biconvex body at angle of attack. It was assumed that a half thickness of biconvex body was unit length. A chord length was varied 20, 60, 100, 200, 400, and an angle of attack was varied from 0 degree to 45 degree. In order to obtain solutions finding the separation point, Momentum equation, continuity equation and Bernoulli's equation were combined and the corditton of separation was found. Equation of Velocity distribution around biconvex body given by Van Dyke was substituted to this condition and solution on each variables were obtained. The result was that seperation point happened at the more back of model as chord length and angle of attack were more increasing.

당뇨병 환자에서 혈장 Thrombin-Antithrombin Ⅲ 및 Plasmin-α_2-Plasmin Inhibitor 복합체의 임상적 의의

김경욱,김은숙,정상수,윤수지,박우일,이준희,남수연,안철우,문병수,김경래,차봉수,송영득,임승길,이현철,허갑범 대한당뇨병학회 2002 Diabetes and Metabolism Journal Vol.25 No.5

연구배경:당뇨병 환자에서 혈액응고 및 섬유소용해 체계의 이상경향이 있어 그 결과로 여러 혈관합병증의 발생위험이 높다는 사실은 널리 알려져 있다. 그 기전은 아직 확실히 밝혀지지 않았으나, 고혈당으로 인한 혈장 단백질들의 비효소성 당화작용이나 산화성 스트레스로 인한 유리 라티칼 작용으로 응고항진이나 섬유소용해 활성의 저하를 유발하는 것으로 생각되고 있다. 최근 응고 및 용해인자와 그 억제자의 복합체들의 증가가 이 상태를 비교적 예민하게 반영한다고 알려져 있다. 방법:본 연구에서는 당뇨병 환자 101명과 정상 대조군 20명에서 혈장내 thrombin­antithrombin complex(TAT)와 plasmin­α₂­plasmin inhibitor complex(PIC)를 측정하여 비교하고, 당뇨병 환자에서 미세혈관 합병증과 대혈관합병증의 유무에 따른 차이와, 이미 혈관 질환의 위험인자로 알려져 있는 인자들간의 상관성을 알아보고자 하였다. 결과:1. 환자의 분포를 살펴보면 혈관합병증이 있는 군은 85명, 혈관합병증이 없는 군은 16명이었고, 평균연령은 각각 57.9±14.1세, 49.9±16.6세로 혈관 합병증이 있는 군에서 더 나이가 많았고, 체질량지수는 23.2±3.4㎏/㎡, 24.1±3.4㎏/㎡로 두 군간 유의한 차이는 없었다. 또 두 군간의 혈압 및 HbA1c, 공복혈당 및 인슐린과 C­peptide, 총 콜레스테롤, 중성지방, HDL­콜레스테롤, Lp⒜는 유의한 차이가 없었고, 미세혈관합병증이 있는 군에서 당뇨병의 유병기간이 길었다. 2. TAT 및 PIC의 농도는 정상 대조군에서는 2.8±1.2 ng/mL, 240.4±69.7 ng/mL이었고, 당뇨병 환자군에서는 9.5±22.6 ng/mL, 472.2±258.7 ng/mL이었다. TAT와 PIC 모두 당뇨병 환자군에서 정상 대조군에 비해 유의하게 증가되어 있었고(p<0.001), TAT/PIC ratio는 두 군간 차이가 없었다. 3. 당뇨병 환자의 혈관합병증에 따른 TAT 및 PIC, fibrinogen 농도는 합병증이 없는 군은 각각 4.1±2.4ng/mL, 362.2±272.0ng/mL, 322.7±102.4mg/mL으로 PIC와 fibrinogen의 증가를 보였으나, 연령을 보정한 후에는 통계학적 유의성은 없었다. 또 대혈관 합병증군에서는 각각 6.0±4.9 ng/mL, 507.4±321.6 ng/mL, 427.1±194.7 mg/dL이었으며 미세·대혈관 합병증군에서는 10.4±6.4 ng/mL, 484.8±269.7 ng/mL, 388.4±132.4 mg/dL으로 TAT의 증가를 보였으나 역시 연령을 보정한 후에는 통계학적 유의성은 없었다. 4. 미세혈관합병증군에서 HbA1c(>8%)가 높은 군의 PIC 농도가 유의하게 높았고(p=0.049), 대혈관합병증군에서 HbA1c(>8%)가 높은 군의 총 콜레스테롤 농도가 유의하게 높았다(p=0.042). 5. 총 당뇨병 환자군에서 PIC는 fibrinogen과 HbA1c와 양의 상관관계를, BMI와 음의 상관관계를 보였으며(r=0.47, 0.31,-0.25), 혈관 합병증이 없는 당뇨병 환자군에서만 TAT는 HbA1c와 양의 상관관계를 보였다(r=0.67). 결론:이상의 결과에서 혈장 TAT 및 PIC 농도는 당뇨병 환자에서 정상 대조군에 비해 의미있게 증가되어 있었고, 당뇨병 환자군에서는 연령의 증가와 유병기간이 혈액응고항진 및 용해의 장애에 큰 역할을 함을 알 수 있었으며, 총 당뇨병 환자군에 PIC와 HbA1c와 양의 상관관계를, BMI와 음의 상관관계를 보였으며 혈관 합병증이 없는 당뇨병 환자군에서만 TAT는 HbA1c와 양의 상관관계를 보였다. 따라서 당뇨병 환자에서 혈액응고 및 용해의 장애가 동반되어 있다고 볼 수 있으며, 혈장 TAT 및 PIC는 혈관합병증으로의 진행을 예측하는 지표로서 유용하리라 생각된다. 또 혈당조절정도와 상관성이 있으므로 혈당조절후에 추적검사를 시행하여 합병증의 예방이 가능한지 추후 연구가 필요하리라 생각된다. Background : Abnormality of coagulation and fibrinolystic system is known as a predisposing factor of vascular complication in diabetes. Although the pathogenesis is not well known, non-enzymatic glycation reaction and the increase in production of free radicals due to an increased oxidative stress may be linked to the hypercoagulibility and hypofibrinolytic activity. As indices of abnormality in coagulation and firinolysis in peripheral blood, plasma thrombin-antithrombin Ⅲ complex (TAT) and plasmin-α_2-plasmin inhibitor complex (PIC) were measured. The purpose of this study was to clarify whether hypercoagulability exists in diabetic patients with or without vascular complication. Methods : In our study, we measured plasma thrombin-antithrombin Ⅲ compelx (TAT) and plasmin-α_2-plasmin inhibit or complex (PIC) in 101 diabetic subjects and 20 controls. Comparing TAT and PIC levels in diabetic microvascular complication group, diabetic macrovascular complication group and controls, we examined correlation between risk factors associated with diabetic vascular complication. Results : 1. The group with diabetic vascular complication was older than group without complication. There was no significant difference in BMI, blood pressure, HbA_ic, blood sugar level, insulin, C-peptide, serum creatinine, total cholesterol, triglyceride, HDL-cholesterol, Lp (a) between two groups. The group with diabetic microvascular complication had longer duration of diabetes. 2. Concentration of TAT and PIC were 2.8±1.2 ng/ mL, 240.4±69.7 ng/ mL in controls and 9.5±22.6 ng/ mL, 472.2±258.7 ng/ mL in diabetic patients, respectively. TAT and PIC were significantly higher in diabetic patients than in control (p<0.001). But TAT/PIC ratio was no significant difference between two groups. 3. In diabetic patients, concentration of TAT and PIC and fibrinogen were respectively 4.1±2.4 ng/ mL, 362.2±272.0 ng/ mL, 322.7±102.4 mg/ dL in group without vascular complication and 5.3±4.1 ng/ mL, 529.5±258.7 ng/ mL, 374.9±106.2 mg/ dL in group with microvascular complication, which group had increase in PIC and Fibrinogen but no significance after correction of age. Concentration of TAT and PIC and Fibrinogen were 60.±4.9 ng/ mL, 507.4±321.6 ng/ mL, 427.1±194.7 mg/ dL in macrovascular complication, and 10.4±6.7 mg/ mL, 484.8±269.7 ng/ mL, 388.4±132.4 mg/ dL in combined vascular complication which group showed increase of TAT but also had no significant increase after correction of age. 4. In diabetic microvascular complication patients, group of high HbA_1c (>8%) (p=0.049) had significant high PIC concentration. In diabetic macrovascular complication patients, group of high HbA_1c (>8%) (p=0.042) had significant high total cholesterol concentration. 5. In all diabetic patients, PIC was positively correlated with fibrinogen and HbA_1c and negatively correlated BMI (r=0.47, 0.31, -0.25). Only in daibetic patients without angiopathy, TAT was positively correlated with HbA_1c (r=0.67). Conclusion : In this study, plasma TAT and PIC concentration significantly increased in diabetic patients compared with controls, and PIC was increased in group with microvascular complication, TAT were increased in group with combined micro macrovascular complication. However, there was no significance relationship existed when correctinf for age. PIC was correlated with HbA_1c. TAT was correlated with HbA_1c only in the group without angiopathy. Abnormality of coagulation and fibrinolysis were combined in diabetes, plasma TAT and PIC can be used as an index of vascular complication. Also we found the correlation with the degree of the blood glucose control. Therefore we need follow up study for the possibility of prevention of vascular complication after controlling the blood glucose to age-matched patients (J Kor Diaabetes Asso 25:354~363, 2001).

Changes in Habitat Use by Female Japanese Pipistrelles (Pipistrellus abramus) during Different Stages of Reproduction Revealed by Radio Telemetry

( Chul Un Chung ),( Sung Chul Kim ),( Young Shin Jeon ),( Sang Hoon Han ) 한국환경과학회 2017 한국환경과학회지 Vol.26 No.7

We analyzed how foraging area use changed in female Pipistrellus abramus during the breeding season. Radio tracking was used to follow 12 female P. abramus in Gyeongju City, from 2013 to 2015. We followed three bats in each of four stages of reproduction: early pregnancy, late pregnancy, lactation, and post-lactation. Our data showed that the usable area of a foraging site and the area that was actually used by bats in that site were different, and foraging site use also differed according to stage of reproduction. The bats used arable land the most, with use rates of 57%, 40.4%, and 73.2% during early pregnancy, late pregnancy, and lactation, respectively. Bats in a post-lactation state did not use arable areas at all and instead foraged over bodies of water 90% of the time. There was no difference in the use of each foraging environment between bats in early pregnancy and late pregnancy. However, bats in late pregnancy and those that were lactating did use arable land to different extents, and bats that were lactating and those that were post-lactation also used arable land and bodies of water to different extents.

Changes in Habitat Use by Female Japanese Pipistrelles (Pipistrellus abramus) during Different Stages of Reproduction Revealed by Radio Telemetry

Chung, Chul Un,Kim, Sung Chul,Jeon, Young Shin,Han, Sang Hoon The Korean Environmental Sciences Society 2017 한국환경과학회지 Vol.26 No.9

We analyzed how foraging area use changed in female Pipistrellus abramus during the breeding season. Radio tracking was used to follow 12 female P. abramus in Gyeongju City, from 2013 to 2015. We followed three bats in each of four stages of reproduction: early pregnancy, late pregnancy, lactation, and post-lactation. Our data showed that the usable area of a foraging site and the area that was actually used by bats in that site were different, and foraging site use also differed according to stage of reproduction. The bats used arable land the most, with use rates of 57%, 40.4%, and 73.2% during early pregnancy, late pregnancy, and lactation, respectively. Bats in a post-lactation state did not use arable areas at all and instead foraged over bodies of water 90% of the time. There was no difference in the use of each foraging environment between bats in early pregnancy and late pregnancy. However, bats in late pregnancy and those that were lactating did use arable land to different extents, and bats that were lactating and those that were post-lactation also used arable land and bodies of water to different extents.

주왕산국립공원 조류의 계절별 종 구성 변화 : 탐방객 수와 탐방로 형태를 중심으로

정철운(Chul-Un Chung),이정일(Chong-Il Lee) 한국조류학회II 2005 한국조류학회지 Vol.12 No.2

새끼 여우의 수유기 행동패턴 변화

정철운 ( Chul Un Chung ),김영채 ( Young Chae Kim ),이화진 ( Hwa Jin Lee ),김성철 ( Sung Chul Kim ),이배근 ( Bae Keun Lee ) 한국환경생태학회 2013 한국환경생태학회지 Vol.27 No.6

본 연구는 새끼 여우의 수유기 행동패턴을 분석하여 생존율 증대 및 효율적인 개체관리에 필요한 생태적 자료구축을 목적으로 실시되었다. 연구는 국립공원종복원기술원 여우복원센터 시설 내에서 2013년 출생 후 관리중인 새끼 여우를 대상으로 수행하였다. 수유 및 굴 외부 출현패턴 분석 결과 새끼의 성장에 따라 일일 수유횟수와 어미의 수유시간은 감소하였으며, 새끼의 굴 외부 출현횟수, 활동시간, 이동거리는 증가하는 것으로 나타났다. 특히 생후 30일이 경과하면서 어미의 수유 행동은 크게 감소하였으며, 새끼의 굴 외부 활동성은 크게 증가하는 결과를 보였다. 따라서 향후 원종 확보를 위한 증식개체 관리시 해당 일자를 기준으로 생물 먹이원의 증가가 필요하며, 야생에서 출생한 새끼의 개체표식을 위한 포획시에도 최소 생후 30일이 경과한 후 진행하는 것이 포획의 용이성뿐만 아니라 새끼의 성장에도 부정적 영향을 최소화 할 수 있을 것이다. The aim of the present study is to obtain ecological data necessary for increasing the survival rate and effective individual management of fox cubs by analyzing the behavioral pattern during the lactation period. The subjects of the present study were baby foxes born in 2013 and taken care of at the species restoration technology institute, Korea National Park Service. Our analysis on the lactation of fox cubs and their appearance pattern outside the burrow revealed that the frequency and duration of lactation decreased with the growth of the cubs, whereas the frequency of the cubs venturing outside the den, activity time, and distance ventured increased. By the 30th day after birth, in particular, the lactation behavior of the vixens largely decreased, and the activity of the cubs outside the den increased accordingly. Thus, for future management of the propagation of fox individuals for securing the original breed, it is necessary to increase the living food source. In addition, while capturing foxes for individual marking of cubs born in the wild, it is desirable to capture cubs older than 30 days not only for easy capture but also to minimize negative influence on the growth of the cub.

카메라 트래핑을 이용한 육상포유류 모니터링 효율성 평가

정철운 ( Chul Un Chung ),차진열 ( Jin Yeo Cha ),김영채 ( Young Chae Kim ),김성철 ( Sung Chul Kim ),권구희 ( Gu Hee Kwon ),이화진 ( Hwa Jin Lee ) 한국환경복원기술학회(구 한국환경복원녹화기술학회) 2014 한국환경복원기술학회지 Vol.17 No.3

The aim of this study was to evaluate the monitoring efficiency of camera trapping in wild animals and to determine ways to increase its utilization. Nineteen sensor cameras were installed in Sobaeksan National Park from October 2012 to September 2013. During the study period, a total of 1045terrestrial mammal photos were secured and 15 species habitats were identified. Shooting frequency was higher for medium and large mammals, especially full images of carnivores accounted for approximately 83%. A comparison of track surveys revealed that camera trapping was highly efficient and helped in capturing real image of species. The supply of lure and bait stimulates the sense of smell in carnivores, which further enhances the capturing of images by camera trapping. The results of this study provide data on the ecological characteristics of mammals, which can aid in determining habitat use by these animals, and thereby facilitate prevention of crop damage by wildlife.

독도에서의 육상포유류 첫 관찰

정철운(Chul-Un Chung),임춘우(Chun-Woo Lim),김성대(Sung-Dae Kim) 국립공원연구원 2010 국립공원연구지 Vol.1 No.3

본 관찰 기록은 대구지방환경청이 실시하는 2010년 독도생태계 정밀조사 사업의 결과로, 2010년 7월 6일 독도의 동도와 서도를 직접 방문하여 조사하였다. 본 조사결과 독도(서도)에서 시궁쥐(사체) 1개체를 확인하였으며, 확인된 개체는 독도 방문선 및 자재운반선 등을 통하여 독도에 유입된 것으로 판단된다. 지금까지 독도의 육상포유류는 독도 경비대가 사육중인 삽살개 외에는 확인되지 않았으나, 수년전부터 거주민에 의한 설치류의 배설물 확인 등 소형포유류의 서식이 이루어지고 있음이 간접적으로 확인된바 있다. 무인도서내 설치류의 유입은 번식조류의 방해요인 및 생태계 교란의 원인을 제공할 수 있다. 따라서 본 조사에서 확인된 시궁쥐의 관찰은 지금까지 확인되지 않았던 독도의 육상포유류에 대한 첫 관찰사례로 향후 독도 생태계 관리에 유용한 자료가 될 것으로 생각된다. This observation record is the result of thorough research on Dokdo s ecosystem conducted by Ministry of Environment-Daegu Office in 2010. For an on-site survey on Dokdo, a real visit to Dokdo was made on July 6, 2010. As a result of this survey, a carcass of the Rattus norvegicus was found and the identified carcass of the Rattus norvegicus was guessed to be brought in through a tourist ship or a material carrier to Dokdo. Until now, it has been known that there is no terrestrial mammal in Dokdo except a shaggy dog bred by Dokdo Police Guard. But since several years ago, some excrement of a rodent was found by the resident in Dokdo, from which the inhabitation of small mammals was indirectly identified. For an uninhabited island like Dokdo, influx of rodents can disturb the breeding of birds and can be a cause of a disturbance of the ecosystem. Therefore, the result of this research seems to be a useful material for the Dokdo ecosystem management in future.

집박쥐의 발성 시그널 발달에 관한 연구

정철운 ( Chul Un Chung ),한상훈 ( Sang Hoon Han ),이정일 ( Chong Il Lee ) 한국환경생태학회 2010 한국환경생태학회지 Vol.24 No.2

본 연구는 박쥐의 연령 증가에 따른 발성 초음파의 변화를 파악하기 위하여 집박쥐(Pipistrellus abramus)를 대상으로 생후 어린 개체가 발산하는 음을 이용하여 세부 분석을 실시하였다. 분석결과 어린 개체는 성체와 다른 복합적이고 다양한 형태의 시그널을 발산하는 것으로 확인되었다. 펄스의 형태는 생후 2일차에는 하모니의 수가 많고 불규칙적인 시그널 형태를 보였으며, 생후 10일차부터 20일 까지는 완만한 FM 시그널 형태를 보였다. 생후 30일 경에는 짧은 시간의 FM 시그널 형태를 보였으며, 40일 이후 점차 성체와 유사한 형태의 시그널을 발산하였다. 어린개체의 성장에 따른 발성 시그널을 분석한 결과 각각의 분석 항목별로 유의적인 차이가 있는 것으로 나타났다. 즉, 펄스의 지속시간 p<0.001), 펄스 간격(p<0.001), 하모니의 수(p<0.001)는 새끼의 연령이 증가할수록 감소하는 경향을 보였으며, 최고진동수(p<0.001), 개시진동수(p<0.001), 종말진동수(p<0.001)는 증가하는 결과를 보였다. 특히 펄스 간격은 생후 5일차에 가장 큰 변화를 보였으며, 그 외 펄스 지속시간, 최고진동수, 개시진동수, 종말진동수는 생후 25일차에 가장 큰 변화를 나타내었다. This study reports developmental changes in the vocal signals produced by infant or young Pipistrellus abramus. In contrast to adult bats, infant bats of the P. abramus emitted calls characterized by multi harmonics and variable signal patterns. Infants at two day of age emitted a irregular signal and showed gentle FM signals between 10 and 20 days. After about 40 days of age, the young bats emitted similar signals to the echolocation calls of adults. As the infant bats growing up, vocal signals trend showen a decrease in pulse duration(p<0.001), pulse interval(p<0.001) and number of harmonic(p<0.001). And the peak frequency(p<0.001), starting frequency(p<0.001) and ending frequency(p<0.001) in infant bats increased with the age. The largest change in pulse interval occurred in 5 days. And the pulse duration, peak frequency, starting frequency and ending frequency of the bat`s sounds changed most dramatically in 25 days of age.

박쥐의(Chiroptera)휴식지로서 교량 이용에 관한 연구

정철운 ( Chul Un Chung ),한상훈 ( Sang Hoon Han ),이정일 ( Chong Il Lee ) 한국환경생태학회 2009 한국환경생태학회지 Vol.23 No.4

주·야간 휴식장소로써 박쥐가 교량(Bridge)을 이용하는 특성을 파악하기 위하여 2007년 7월부터 2008년 10월까지 경상북도 남동부 지역의 수계에 조성된 81개 교량을 조사하였다. 조사결과 교량을 휴식장소로 이용하고 있는 종은 관박쥐 Rhinolophus ferrumequinum, 집박쥐 Pipistrellus abramus, 검은집박쥐 Hypsugo alaschanicus, 우수리박쥐 Myotis petax, 쇠큰수염박쥐 Myotis ikonnikovi, 문둥이박쥐 Eptesicus serotinus 등 6종이 확인되었다. 총 7개 유형의 교량 가운데 거더(girder)가 조성되어 있는 3개 유형의 교량에서만 박쥐의 이용이 확인되어 교량에 있어 박쥐의 휴식장소 이용은 교량의 구조적 특징에 의해서 영향을 받는 것으로 나타났다. 구조적 특징을 제외한 환경요인으로는 교량의 주변 산림, 경작지, 교량 하부의 차량통행 여부 등의 요인이 박쥐의 교량내 휴식활동에 영향을 미치는 것으로 확인되었다. This study was conducted to investigate the bat`s characteristic of using a bridge as a roosting site during the daytime and nighttime. 81 bridges built in the water system of the southeastern area of Gyeongsangbuk-do were investigated from Jul. 2007 to Oct. 2008. The species which use a bridge as a roosting site were 6 species of Rhinolophus ferrumequinum, Pipistrellus abramus, Hypsugo alaschanicus, Myotis petax, Myotis ikonnikovi and Eptesicus serotinus. There were 7 types of bridges in which three of them had a girder. This kind of structural characteristics are used for a roosting site of bats. There were other factors as well influenced on the utilizing it such as forest, vehicle passing under the bridge, and cultivated land around a bridges.