Prevotella nigrescens의 용혈특성에 관한 연구

곽주석,장훈상,장석우,이수종,유용욱,민경산 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.4

세균의 용혈활성은 세균이 숙주 내에서 생존하기 위해 필요한 철을 획득하기위한 특성이며 기능면에서 볼 때 숙주에 대한 중요한 독력인자로 간주될 수 있다. 본 연구에서는 괴사치수 및 치근단 치주염으로 진단된 환자의 근관에서 분리한 Prevotella nigrescens의 용혈활성을 다양한 조건 하에서 측정하여 그 특성을 규명하는 것을 목적으로 한다. 1. 임상에서 분리한 P. nigrescers와 표준균주인 P. nigrescers ATCC 33563에서 모두 용혈활성이 나타났다. 2. 사람, 면양 및 말 세 가지 종에 대해 용혈활성을 비교한 결과 사람의 적혈구에서 가장 강한 용혈활성을 나타내었다. 3. 용혈소 억제제인 NaN₃와 dithiothreitol (DTT)는 농도의존적으로 P.nigrescers의 용혈활성을 감소시켰다 (p<0.05). 4. P. nigrescers가 최대 용혈활성을 나타내는 최적의 pH는 4이었으며, 50℃이하의 온도에서는 용혈활성을 보였으나 95℃에서 급격히 감소하였다. 5.배양조건에 따른 P. nigrescens의 용혈활성을비교한 결과 10% CO₂배양기에 배양한 경우혐기성 조건에서 배양한 것보다 더 높은 용혈활성을 보였다. Hemolytic property is a specific feature of bacteria to obtain iron which is essential for its survival in host tissues. Therefore, it is thought to be one of several factors of virulence. The purpose of this study was to investigate the hemolytic properties of Prevotella nigrescens isolated from the teeth diagnosed as pulp necrosis and apical periodontitis under the presence of hemolysin inhibitors such as NaN3 and dithiothreitol, heat, various pH and cultural conditions. The results were as follows; 1. Clinically isolated P. nigrescens strains and standard P. nigrscens ATCC 33563 showed hemolytic activity. 2. P. nigrescens showed higher hemolytic activity against human erythrocytes than sheep or horse erythrocytes. 3. NaN₃ and dithiothreitol (DTT) reduced the hemolytic activity of P. nigrescens in a dose dependent manner (p<0.05). 4. Optimal pH for the maximum hemolytic activity of P. nigrescens was 4.0 and the hemolysin was stable under the 50℃, but the hemolytic activity was significantly decreased at 95℃. 5. P. nigrescens cultured in 10% CO₂ condition showed higher hemolytic activity than the bacteria cultured in the anaerobic condition.[J Kor Acad Cons Dent 30(4):335-343,2005]

잠재적 산림생태공원에 대한 소비자 선호분석 : 조건부 선택법을 적용하여 Using A Contingent Choice Method

곽승준,유승훈,한상용 한국경상학회, 한국국민경제학회 2003 경제연구 Vol.21 No.3

본 논문은 컨조인트 분석법의 일종인 조건부 선택법을 이용하여 응답자들에게 광교산 산림생태공원의 개별 속성들과 가격속성간의 상층관계(trade-offs)를 고려하도록 함으로써 소비자 선호에 근거한 잠재적 산림생태공원의 개별 속성별 화폐가치를 유도하고자 한다. 아울러 조건부 선택법의 적용을 위해 준수해야 할 다양한 방법론적 기준과 절차들(적절한 속성 및 속성수준, 그리고 지불수단의 선택, 통계적 방법을 이용한 실험계획법의 운용 등)을 체계적으로 설명한다. 분석결과, 조건부 선택질문에 있어 응답자들은 전반적으로 잠재적 산림생태공원의 개별속성들과 가격사이의 상층관계를 잘 이해하고 응답하였으며, 추정모형으로부터 도출된 개별속성들에 대한 한계 지불의사액 추정치들은 대부분 통계적으로 유의하였다. 그리고 모형2에서 잠재적 산림생태공원의 개별 속성에 대한 가구 당 연평균 한계 지불의사액은 보전녹지가 약 41.6(원/%), 동물종이 약 18.5(원/종), 이용제한이 약 107.9(원/수준), 산림생태교육장이 약 202.5(원/개)으로 분석되었고, 개별 속성들의 최상위 수준으로 구성된 광교산 산림생태공원의 연평균 경제적 편익은 평균적으로 약 93억원에 달하였다. 본 연구는 정책 결정자들에게 수도권지역에 널리 분포되어 있는 잠재적 산림생태공원지역에서의 무분별한 개발행위를 방지하고 환경 친화적 도시개발계획을 위한 정량적 정보를 제공할 뿐만 아니라 도시개발사업과 관련한 의사결정과정에서 유용하게 활용될 수 있다. The objective of this paper is to quantify economic values of multiple environmental attributes of the potential forest park, using contingent choice method which allows respondents to consider trade-offs among multiple attributes. In addition, this paper systematically explains methodological guidelines and procedure(e.g., selection of a set of attributes and magnitude of attribute levels, selection of payment vehicle, and operation of experimental design based on statistical method). As a result, the choice works for selecting a preferred option among three alternative options were within respondent's ability and the marginal willingness-to-pay estimates across two models were statistically different from zero. And, according to model 2, the marginal value for multiple attributes of potential forest park is calculated as about 41.6(won/Percent) for reserved areas, about 18.5(Won/Species)for fauna species, about 107.9(Won/Level) for recreation restrictions, and about 202.5(Won/Level) for ecological museums, respectively, the total economic value for the forest park option with the highest levels was annually estimated as about 9.3 billion Won. This study provides quantitative information useful to help policy-makers to prevent reckless deforestations and to establish an environment -friendly land development project in the Seoul metropolitan area. Also, the results can be useful in the decision-making process for incorporating such quantitative information in their evaluation of various forest park options under consideration.

입원한 정신분열병 환자의 사망원인

곽상곤,서상훈,남정현 漢陽大學校 精神健康硏究 1997 精神健康硏究 Vol.16 No.-

CMT 이미지 코딩과 성능 측정

郭勳星 全北大學校 1989 論文集 Vol.31 No.-

The discrete cosine transform(DCT) has been widely used in digital image processing because of its nearly optimal performance. For computational requirements, efficient methods reported for DCT are the Algorithms proposed by chen et al[11] and by Hein et al [2]. The CMT, called the conversion matrix transform has the following properties. 1. The conversion matrix has sparse block diagonal structure. 2. The conversion matrix has only integers as its elements. Only integer arithmetic is involved. 3. Its performance is very close to the DCT. The hardware requirements and implementation are also presented for the CMT. Because of the integer arithmetic, computationally it is much simpler. Image coding for the GIRL is simulated and performance measurements for the various discrete transforms are compared. The CMT is found to yield almost the same picture quality.

MCT의 고속계산 알고리즘과 성능 측정

郭勳星 全北大學校 1987 論文集 Vol.29 No.-

The discrete cosine transform has widely used in digital image processing and computer vision etc. because of its nearly optimal performance. An approximation to the discrete cosine transform, called the modified cosine transform (MCT) is developed. The various performance measurements such as variance distribution, mean square error, rate distortion, and decorrelation prove its closeness to the discrete cosine transform. The fast MCT algorithm proposed here requires fewer arithmetic operations (multiplications and additions) compared to the discrete cosine transform.

수도권 도시림 보존의 경제적 편익 추정 : 광교산을 중심으로 The Case of Mt. Kwanggyo

곽승준,유승훈,한상용 한국환경경제학회 한국자원경제학회 2003 자원·환경경제연구 Vol.12 No.1

Urban forests have various environmental benefits, contributing to the quality of urban life. However, these values have been underestimated or never been reflected in the urban development planning in Korea. As a result, a number of forests in urban areas were either partly or wholly destroyed without their public's values being assessed explicitly. The objective of this paper is to estimate the economic benefits attached to Mt. Kwanggyo in the Capital Region using contingent valuation method, aiming to provide policy-makers with useful information to make an informed public decision in urban development planning. The survey was carefully designed and implemented to meet a number of recommendation rules suggested in the literature. The overall results show that the respondents well accepted the contingent market and would be willing to pay a significant amount for the proposed program of conserving the mountain. Total economic benefits for the population amounted to approximately 3.8 billion Korean won per year. This quantitative information can be used in cost-benefit analysis of urban development plans.

발전부문별 국민경제적 파급효과 분석 : 산업연관분석을 적용하여 Using an Industrial Linkage Analysis

곽승준,유승훈,한상용 한국환경경제학회 한국자원경제학회 2002 자원·환경경제연구 Vol.11 No.4

The electric power industry has played an important role in dramatic economic development in Korea and the electricity has constituted a critical factor sustaining the well-being of the Korean people. This study uses input-output analysis to investigate the role of four electric power sectors (hydro-electric, fossil-fuels, nuclear and non-utility) in the Korean national economy for the period 1985-1998, focusing on four topics: the impacts of electricity supply investments, the electricity supply shortage effects, and the impacts of the rise in electricity rates, and the inter-industry linkage effect. The overall results reveal that non-utility electric sector is superior in terms of the national economy-wide effects to other three sectors throughout the period. Finally, potential uses of the results are illustrated from the perspective of policy instruments and some policy implications are discussed.

IEEE 802.11a OFDM System을 위한 파이프라인 구조인 R4SDC와 R2²SDF IFFT/FFT 모듈의 설계 비교

이창훈,곽성민,강봉순 동아대학교 정보기술연구소 2003 情報技術硏究所論文誌 Vol.11 No.1

The IFFT/FFT module takes charge of modulation and demodulation part and is critical to performance of the OFDM system, that is, error from the IFFT/FFT module is very critical to the whole system. Therefore, when implementing the hardware, minimizing error of the IFFTEFT module is essential. In this paper, we design this IFFT/FFT. The designed IFFT/FFT is the 64-point FFT to be compatible the IEEE 802.11a standard and the pipeline architecture which needs no serial-to-parallel and parallel-to-serial converter. The design methods are the R22SDF (Radix-22 Single-path Delay Feedback) and R4SDC (Radix-4 Single-path Delay Commutator) architecture. We are focusing on the hardware structure considering the OFDM and errors that occur in the IFFT/FFT design step, such as Scaling, Coefficient and Round-off error.

緯度와 地形에 따른 溫帶中部 溪谷植生의 種多樣性 및 群集構造에 關한 硏究

尹相旭,辛壽哲,郭東勳,金昌浩 동국대학교 농림과학연구소 1994 農林科學 論文集 Vol.18 No.-

This study was Carried out to analyse species composition, species diversity and structure and variation trends of vegetation, of Mt. Odae, Mt. Sobaek, and Mt. Juwang following various latitudes and topographies which were in middle temperate zone in Korea. Obtained results are as follows : 1. As a result of the simple discriminant analysis, soil texture Showed the highest high percent contribution of each environmental factor to the discriminant of Studred area. And Mt. Odae showed high content of sand while Mt. Juwang Showed silt. 2. Mean stem density showed highest value in Mt. Juwang and mean D. B. H. was Mt. Odae, and on phisiographic locations showd high values of stem density and mean D. B. H in slow slope area, nothern aspect area, and high elevation area, in order. 3. Species that showed the highest importance value in each canopy-subtree-shrub layer in study area were Quercus mongolica-Acer pseudo-sieboldianum-Lindera obtusiloba were in Mt. Odae, Betula platyphylla var. japonica-Styrax obassia-Deutzia parviflora were in Mt. Sobaek, and Pinus densiflora-Acer pseudo-sieboldianum-Lindera obrusiloba were in Mt. Juwang. 4. Species that showed the highest importance value in each canopy-subtree-shrub layer on the physiographic location were Quercus mongolica-Acer pseudo-sieboldianum-Lindera obtusiloba in high elevation and southern aspect, Carpinus laxiflora-Acer pseudo-sieboldianum-Lindera obtusiloba in high elevation and southern aspect, Carpinus laxiflora-Acer pseudo-sieboldianum-Lindera obtusiloba in nothern slope, Carpinus laxiflora-Styrax obassia-Lindera obtusiloba in low elevation, and Betula platyphylla var. japonica-Styrax obassia-Deutzia parviflora in high elevation. 5. According to decrease of latitudes with going down from Mt. Odae to Mt. Juwang, the more Number of species and individuals were increased, and the deversity index was the highest value in Mt. Sobaek, the evenness was in southern aspect, and the dominance was in high elevation. 6. As a result of Cluster analysis, the study area were divided into 4 groups, Carpinus laxiflora community, Styurax obassia community, Deutzia parviflora community, and Quercus mongolica community. 7. As a result of COA analysis, communities of the study area were divided into Betula platyphylla var. japonica community, Deutzia parviflora community, Quercus mongolica-Acer pseudo-sieboldianum community, and species were divided into 4 groups as the major, the disturbed, the waterside, and the fertile. 8. As results of the simple discriminant analysis and the linear regression, sand and silt content, slope aspect, total nitrogen content, and elevation among environmental factors had high percent contribution to classification and ordination of vegetation communities of the study area. 9. Major tree species had the unstable layer structure due to lower importance values of canopies and subtrees than those of shrubs, and Pinus laxiflora and Betula platyphylla var. japonica were on the decline phase due to very low dominance and absence of next generation. while, Styrax obassia and Acer pseudo-sieboldianum were sustanable layer structure as being distributed on all the crown layer.

Systolic Array를 이용한 2차원 Slant transform

박민식,곽훈성 全北大學校 1990 論文集 Vol.32 No.-

This paper proposes systolic array for 2-D Slant transform. Compared the conventional method with the proposed 2-D Slant transform without matrix transposition, it is required the same latency and twice as PE's. Also, it is shown that the systolic array for 2-D Slant transform is feasible.