비정렬격자 격자점 중심 압력기반해법

최형일,맹주성,이도형 漢陽大學校 工學技術硏究所 2001 工學技術論文集 Vol.10 No.-

본 논문에서는 연속류 영역과 미끄럼류 영역의 유동을 수치계산하기 위한 혼합 비정렬격자 압력기반해법을 제안한다. 압축성 효과를 반영하는 수정된 SIMPLE법을 비정렬격자 격자점 중심법에 적용하였다. 대류항은 2차의 중앙차분법을 지연수정법으로 이산화 하였으며, 확산항은 2차 정화도의 유사 정렬격자 기법을 사용하였다. 또한, 혼합 비정렬격자에서 기억장소의 절약과 계산 효율을 저하여 모서리 자료구조와 격자점 중심법을 사용하였다. 연속류 영역 뿐 만 아니라, 미끄럼 유동의 벽면에서의 미끄럼 현상을 해석할 수 있도록 미끄럼 경계조건을 부과하였으며, 여기에는 널리 쓰이는 Maxwell 경계조건과 명에 의해 새로이 제안된 Langmuir 경계조건을 사용하였다. 제안된 수치기법을 이용하여 연속류 영역의 유동과 미끄럼류 영역의 유동에 대해 수치 계산을 수행하였으며, 본 기법의 정확도와 효율성을 입증하였다. This paper proposes a pressure based method to compute both continuum flow and slip flow on hybrid unstructured grids. The compressible version of SIMPLE algorithm is extended to unstructured grids. Convection terms are discretized using second order central differencing with deferred correction approach and diffusion terms by second-order structured grids analogy. This method also uses cell vertex scheme with edge based data structure in order for memory savings and computing efficiency for arbitrary grid topologies. As well as continuum flow, slip flows are solved by adopting slip boundary conditions, which are well known Maxwell condition and Langmuir condition recently proposed by Myong.(30) The flows in both continuum regime and slip flow regime are calculated using the above methodology, which shows that the proposed method is well-devised with respect to accuracy and efficiency.

흰쥐 적출 대동맥에서의 알파-1 아드레날린성 수용체 탈감작 현상

최도희,한형수,박정숙,김중영 慶北大學校 醫科大學 1994 慶北醫大誌 Vol.35 No.4

목적 : 흰쥐의 적출 대동맥 절편에서 알파-1 아드레날린성 수용체의 탈감작에 따른 수축력 변화를 확인하고 수축력 변화와 관련된 요인들과의 관계를 검정하기 위해 실시되었다. 대상 및 방법 : Sprague-Dawley rat의 대동맥을 적출하여 알파-1 아드레날린성 수용체 선택적 효현제인 phenylephrine으로 탈감작시킨 뒤 수축력과 이완력의 변화를 확인하였다. 결과 : Phenylephrine에 의한 수축력은 phenylephrine 탈감작에 의해 감소되었다. EDRF와 관련이 있는 이완제인 acetylcholine과 histamine에 의한 이완반응은 phenylephrine 처치로서 변화를 볼 수 없었으나 sodium nitroprusside에 의한 이완은 항진되었다. 탈감작현상은 LNMMA와 methylene blue처치로 인해 영향을 받지 아니하였다. KCl에 의한 수축은 phenylephrine 탈감작으로 억제되었으나 phorbol ester에 의한 수축은 phenylephrine 탈감작으로 인해 영향을 받지 아니하였다. 결론 : phenylephrine에 의해 나타나는 알파-1 수용체 탈감작에 따른 수축력 감소 현상은 이완 작용의 변화와는 관련이 없으며 수축기전의 변화, 특히 calcium에 대한 반응성의 변화에 기인함을 시사하였다. We evaluated alpha 1 adrenergic receptor desensitization and decreased contractility in isolated rat aorta. 4 hour exposure to 10^-5M of phenylephrine (phenylephrine exposure) decreased phenylephrine(10^-10 to 10^-5M)-induced contractility. Phenylephrine exposure had no effect on the relaxation by NO releasing agents, such as acetylcholine(10^-9 to 10^-5M) and histamine(10^-8 to 10^-4M), but enhanced nitroprusside(10^-10 to 10^-6M)-induced relaxation. Phenylephrine-induced desensitization was not altered by the presence of methylene blue and N-monomethyl-L-arginine. After phenylephrine exposure KCl-induced contractility was decreased but phorbol ester-induced contractility was not changed. From these results we can assume that prolonged phenylephrine exposure alter calcium-dependent contraction mechanism and involve in alpha 1 adrenergic receptor desensitization-mediated decrease in contractility.

월출산국립공원 수질특성에 관한 연구

최형일,김난희,강영주,채희정,김연풍,조도호,설동화 조선대학교 환경공해연구소 2007 環境公害硏究 Vol.20 No.1

Because mountain streams have narrow widths and steep slopes compared to streams and lakes, hours of immobility are considerably short, and the quality of mountain streams has been greatly influenced by rainfall, land-use, components of the streambed and types of forests. During the summer when heavy rainfall occurs, eroded earth and sand flow into mountain streams and cause temporarily high turbidity. It is also the cause of eutrophication, which is frequently found in downstream. As evaluation standards for the quality of mountain streams were not established in Korea, this quality was evaluated by examining some items based on quality standards for drinkable water and research on the influences of pollution in mountain streams, which showed that these were seldom in downstream water systems. Mountain streams within Wolchulsan National Park flow into a reservoir and when characteristics of mountain streams from forests and rainfall that flow into mountain streams through forest ecosystems were studied, results of measuring its changes are as follows. Monthly changes of pH were low between April and August and higher starting October, and the EC was measured higher in the winter and the spring and tended to be low starting April. The EC on the 19th of May and the 23rd of October and the concentration of floating materials and COD_(Mn) were observed to be higher due to the influence of rainfall on the 19th of May and the 22nd of October, and it was judged that the washing out of dried deposits attached to the water pipe and the leaching of woods were influenced by rainfall. It is considered that real-time monitoring of water quality for a long time and water quality conditions during and after rainfall should be examined for ensuring basic data of water quality and evaluating characteristics and seasonableness of mountain streams, which may be greatly changed by artificial influence in the future.

담양신설 IC의 교통소음도 조사연구

최형일,강영주,채희정,김연풍,조도호,설동화,정숙경 조선대학교 환경공해연구소 2007 環境公害硏究 Vol.20 No.1

After the vehicle has become a large formation with high-speed, loud noise from an express highway is increasing, and the number of large-scale apartment complexes, which are recently being constructed in the metropolitan area nearby the express highway and IC, is increasing gradually. Compared with a main road, the traffic volume and the speed of a vehicle between IC and the ramp way [turn-off] are smaller. If the ramp way is rightly connected with the downtown area, however, the traffic-noise that comes about in surrounding areas will be in conjunction with the traffic-noise from the main road of express highway and that of the ramp way. This research has selected a place that hasn't had a road or a commercial quarter nearby the main-road of IC and ramp way. Then we have studied the traffic-noise status under minimizing influence of its outer-noise, which occurs in IC. 1. The traffic volume change of a small and full-sized car with time has been kept on regularity in 2004 and 2005. As the traffic volume of a full-sized car has diminished remarkably, it has been maintaining through 6:00a.m.-10:00 a.m. As it has decreased since lO:OO a.m.. we have also observed the traffic proportion going up. 2. Monthly traffic volume of small cars was higher in May, August and October than other months. We have observed that the high traffic volume during these months is due to the following: May-The Damyang festival, August-a high-demand season, October-viewing scarlet maple leaves. Monthly traffic volume of full-sized cars was generally higher in August, but it has decreased during 2006. This was due to the many construction trucks that were working on the extension of the 88 Olympic expressway. Therefore, there was more traffic volume in 2006 compared to 2004 and 2005. 3. In this study, the noise figures have been less than 55 dB(A) in 18 spots. There were 14 spots from 55dB(A) to 58dB(A). 58-61dB(A) : 20, 61-64dB(A) : 17, 64-67dB(A) : 18. There were 8 spots we observed at the highest level from 67dB(A) to 70dB(A). Those were the nearby spots separating the main road and Damyang IC. 4. Traffic-noise at the boundary between IC and the main road of an expressway was higher than that of the same distance in other places. 5. We have observed that traffic-noise is low in places with mountains that serve the role of soundproofing walls. Thus, the fundamental sound hadn't affected it.

분진의 개수농도 및 질량농도에 입각한 서울시 지하철 역사내 오염원의 기여도 결정

최형욱,황인조,김신도,김동술 한국대기환경학회 2004 한국대기환경학회지 Vol.20 No.1

The subway play an important part in serious traffic problems. However, because subway system is a closed environment, many serious air pollution problems occurred in subway stations and injured passenger's health. Therefore, it is a necessary to identify sources and to estimate pollutant sources in order to protect passenger's health and to keep clean subway environment. The purpose of this study was to analyze a air quality in the subway stations and to apply a new receptor methodology for quantitatively estimate of PM 10 sources. In this study, the size distributions of particulate matters has been measured by using Aerosizer LD (U.S.A., API, Inc.). It's realtime measurement capability of time-of-flight technique offers a significant advantage of user convenience and air pollution management. Also, the mass concentrations of PM 10 has been measured by using mini-vol portable sampler (U.S.A., Airmetrics Co.). The sampling performed in Seoul subway stations during the period of February 2000 and April 2000. The number distribution data used in this study consisted of 26 raw data sets in the Jongno-sam-ga station. Correlation Analysis can be used in subway stations for source separation and identification. Then, number contribution from each source is determined by the particle number balance (PNB). The mass concentration data used in this study consisted of 31 raw data in the 8 different stations. The mass contributions of PM 10 sources in the concourse by using PMF/CMB model.

돼지 신장세포(PK15)의 이종이식 거부반응에 대한 재조합 IL-18의 영향

최연실,김은미,김영관,박상연,심정현,윤도영,강형식,명평근 충남대학교 생물공학연구소 2004 생물공학연구지 Vol.10 No.1

Various cytokines including IL-1β, IL-2, IL-4, IL-10, IL-12p40, IFN-γ, and TNF-α have been recently reported to play important roles in both host and donor cell activations during xenotransplantation. Interleukin (IL)-18, a proinflammatory cytokine, can induce IL-4 and IL-13 production in T cells, NK cells, B cells, mast cells, and basophils. IL-18 has the capacity to stimulate innate immunity and both Th1-and Th2- mediated responses, but little is known to involve in the xenograft rejection. In order to investigate the role of IL-18 in xenograft rejection, we transplanted the pig kidney (PK15) cells to C57BL/6 mouse with or without intraperitoneal injection of mouse recombinatant IL-18. It was analyzed the population of T cell, B cell and NK cell in the mice transplanted with PK 15 cells and recombinant IL-18 by flow cytometry. We found that splenic CD3+ T cells were increased in mice injected PK15 cells with recombinant IL-18. These results suggest that recombinant IL-18 is critical in the xenograft rejection by increasing T cell population of the recipients.

도로교통소음의 수평·수직적 전달 및 감쇠 특성

최형일,채희정,김연풍,조도호,설동화,정숙경,김정애 조선대학교 생산기술연구소 2007 生産技術硏究 Vol.29 No.1

This study has been conducted to achieve the following objectives: First, in order to understand the horizontal propagation and attenuation characteristics for the road traffic noise, we selected actively developed areas within 100 meters away from the road to measure the level of traffic noise near a road. To measure the noise near a railroad, we selected areas within 100 meters away from the road. In this way, we analyzed the horizontal propagation and attenuation characteristics for the traffic noise occurring in diversified areas. Second, in order to understand the vertical propagation and attenuation characteristics for the road traffic noise, we measured and analyzed the distributional characteristics of vertical sound pressure levels on each floor of multi-storied apartment buildings according to changes of traffic load and types, and the existence or nonexistence of soundproof walls. For the case of the road traffic noise, we also selected we measured and analyzed the different noise levels on each floor of multi-storied apartment buildings from the soundproof wall. The results of Horizontal propagation and attenuation characteristics for the road traffic noise are as follows: In cases of the soundproof wall + raising ground, raising ground, cutting land, and flat land as distance increases, the sound pressure level steadily decreases. The soundproof wall + raising ground has an especially high distance decrease compared to the other areas, and the sound pressure level for the raising ground is higher than that of the cutting land with a measurement of 10.7~12.1dB(A). Vertical propagation and attenuation characteristics for the road traffic noise are as follows: The amount of sound pressure level decrease is 12.6- 14.5dB(A) for first floor when measuring the vertical sound pressure levels at soundproof wall, which indicates a fairly large decrease. At fifth and sixth floor, the amount of decrease is 2.3dB(A), which indicates a small decrease.

돼지 신장세포(PK15)의 이종이식 거부반응에 대한 재조합 IL-18의 영향

최연실,김은미,김영관,박상연,심정현,윤도영,강형식,명평근 충남대학교 형질전환복제돼지연구센터 2004 논문집 Vol. No.8

Various cytokines including IL-1β, IL-2, IL-4, IL-10, IL-12p40, IFN-r, and TNF-α have been recently reported to play important roles in both host and donor cell activations during xenotransplantation. Interleukin (IL)-18, a proinflammatory cytokine, can induce IL-4 and IL-13 production in T cells, NK cells, B cells, mast cells, and basophils. IL-18 has the capacity to stimulate innate immunity and both Th1-and Th2- mediated responses, but little is known to involve in the xenograft rejection. In order to investigate the role of IL-18 in xenograft rejection, we transplanted the pig kidney (PK15) cells to C57BL/6 mouse with or without intraperitoneal injection of mouse recombinatant IL-18, It was analyzed the population of T cell, B cell and NK cell in the mice transplanted with PK 15 cells and recombinant IL-18 by flow cytometry. We found that splenic CD3+ T cells were increased in mice injected PKl5 cells with recombinant IL-18. These results suggest that recombinant IL-18 is critical in the xenograft rejection by increasing T cell population of the recipients.

離岸堤에 의한 海雲臺海濱의 浸蟲防止에 관한 實驗的 硏究

閔丙亨,崔道碩,閔一圭,李東明 東亞大學校 海洋資源硏究所 1989 硏究論文集 Vol.2 No.1

A three-dimensional hydraulic model test was accomplished to study nourishment effects on the lengths, apperture width of offshore breakwaters and the site where they are to be built when they were adopted as an erosion protection method in HAEUNDAE beach which is showing obvious erosion phenomena. The experimental results showed that the nourishment effects can be maximized when the length and aperture width of offshore breakwaters are 200m, 100m, respectively, and the water depth at which they are located is about 3m.

구멍연잎성게, Astriclypeus manni (VERRIL1867) 의 먹이섭취, 서식밀도 및 이동속도에 관하여

강도형,최광식 한국환경생물학회 2002 환경생물 : 환경생물학회지 Vol.20 No.2

부정형성게류인 구멍연잎성게는 제주도 연안에 널리 분포하고 있음에도 불구하고 생태학적 연구들이 미비한 실정이다. 이 연구는 구멍연잎성게의 행동학적 연구로서 먹이섭취, 서식밀도 및 이동에 대한 기초자료로서 시료는 제주도의 북동쪽에 위치한 함덕에서 SCUBA를 통하여 채집 및 현장에서 직접 관찰하였다. 장내용물 관찰 결과, 장내 퇴적물 입자의 평균 입도조성은 77.6±22.2 μm였다. 장 내용물은 유공충, 저서성 요각류, 선충류, 규조류, 알, 해조류의 파편, 골편 등의 동식물 플랑크톤으로 구성되었다. 구멍연잎성게의 서식밀도는 1m^2당 0.4개체이며, 분포패턴은 임의분포(random distribution)에 기초하는 것으로 판단되었다(X^2=85.16, P>0.05). 구멍연잎성게의 이동거리는 여름철인 1998년 8월에 6.2∼64.8 cm hr^-1 (mean = 25.0±13.9)이었고, 5월에는 2.O~43.Ocm hr^-1(mean=17.7±10.7)로 8월에 다소 높게 나타났다. 여름기간 중 관찰된 비교적 빠른 이동속도는 먹이 섭이 활동과 관련된 것으로 추정되었다. Sand dollar, Astriclypeus manni (Echinodermata: Echinoidea) is widely distributed on subtidal sand flats all along the coast of Cheju Island. Limited information has been reported on their ecology despite their abundance. This study reports gut contents, density and locomotion of the sand dollars distributed on a subtidal sand flat on the north-east coast of Cheju Island. Microscopic examination of the gut contents indicated that A. manni feeds on inorganic and organic detritus as well as live organisms contained in the sediments. Inorganic particles included sand grains, sponge spicules and shells of benthic animals such as foraminifera, crustacean and molluscs. Mean diameter of sediment particles retained in the gut was 77.6±22.2㎛. Live organisms retained in the gut included foraminifera, harpacticoid copepods, nematodes, diatoms and unidentified egg. Spatial distribution pattern of the sand dollar was found to be random with a mean density of 0.4 individual m^-2(??^2=85.16, p>0.05). Locomotion speed of the sand dollar measured in situ was 2.0 to 65.0 ㎝ hr^-1. Locomotion speed and moving distance was somewhat higher in summer when food availability also higher.