소규모 사무공간에서 건물 개구부에 따른조명에너지 성능평가를 위한 노모그래프 개발

고동환,김한성,조동우,김강수 대한건축학회 2004 대한건축학회논문집 Vol.20 No.3

The purpose of this study was to analyze daylighting performance in a small size office space fenestration for lighting energy conservation. DOE2.1E was used for simulations for the model space of 3??.6m. Nomographs were developed which could simulate work plane illuminance, glare index, energy consumption and energy reduction rate for day lighting design. Major results of simulations are as follows; 1) Simulation results show that 45-48% of lighting energy can be saved by using daylight dimming systems. 2) When blinds facing south were installed, 42% of workplane illuminance diminished, but the glare index didn't exceed the recommended max-glare value. 3) In the office space facing south, energy consumption rate in the case space of 500 lux workplane illuminance is larger than the case space of 300 lux workplane illuminance. Therefore, energy reduction rate is increased when the office faces south and maintains 300 lux workplane illuminance level.

심부 지층 모형의 중력 자료 역산

고진석,서동우 조선대학교 동력자원연구소 1994 動力資源硏究所誌 Vol.16 No.2

Gravity inversion is an iterative least-squares technique to obtain parameters of anomalous mass from gravity measurements. In this paper, the iterative least-squares inversion method is used to determine shapes and density contrasts of 2-D structures from the gravity data. The 2-D structures are represented by their cross-sections of N-sided polygons with density contrasts which are constant. Gravity data are calculated by theoretical formulas for the above structure models. The data are considered as observed ones and used for inversions. The inversions are performed by the following processes : 1) polygon's vertices and density contrast are initially assumed, 2) gravity are calculated for the assumed model and error between the true (observed) and calculated gravity are determined, 3) new vertices and density contrast are determined from the error by using the damped least-squares inversion method, and 4) final model is determined when the error is very small. Results of this study show that the shape and density contrast of each model are accurately determined when the density contrast is constant. Inversion of this study can be employed to improve the reliability and effectiveness of gravity interpretation and the following techniques are applied to make improvements on the stability of the inversion process : 1) alternative choice of the number of vertices. 2) carefully selecting an initial model.

과도 절삭에서의 절삭 공정 시뮬레이션

고정훈,조동우,윤원수,김주한 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

In most of the existing mechanistic models, the cutting process simulation is often restricted to a single path machining operation under a fixed cutting condition. Complex cutting processes such as die or mold manufacturing, however, are performed under two- or three-dimensional multiple tool paths. Since the tool paths in CNC machining are composed of line and arc segments, transient cuts are frequently occured due to the multiple paths. Even in steady cuts, the width of cut is varied with each segment. In this regard, this paper deals with the development of process simulation system for transient cuts, where continuously changing cutting configuration is computed, and then the cutting forces are predicted.

역시간 구조 보정을 이용한 지질구조 해석

고진석,서동우 조선대학교 에너지.자원신기술연구소 2000 에너지·자원신기술연구소 논문지 Vol.22 No.1

Conventional wave equation migrations correct the reflector shape using extrapolation and imaging with initial boundary condition on the surface. The wave equation migration using paraxial approximation can not migrate multiples, S wave, and common shot gather data. One way to complete this defect is to use a full waveform inversion technique which needs much computing time in calculating the wave fields and partial derivative seismograms for each model guessed iteratively. In this thesis two new methods are studied which image the subsurface by the partial derivatives, with respect to layer parameters, of the cross-correlation of observed and model data. The one method is to image the subsurface by inner product, cross-correlation, of the observed data and partial derivative seismograms which are calculated from the virtual sources determined from synthetic seismogram for a guessed model and partial derivatives of the guessed model with respect to velocity. The other method is to image the subsurface by crossprrelation of the virtual sources and the back propagated wave fields calculated from the observed data. The cross-correlation in each of the two method has large values at layer interfaces even if the initially guessed model is quite different from true model. Therefore, no iterative modification of the guessed model is necessary by this methods. This fact gains an advantage over the migration using iterative ful! waveform inversion.

수직 밀도 구배를 가진 지질 구조에서의 중력 자료 역산과 목적함수 특성

고진석,서동우,강추원 조선대학교 동력자원연구소 1995 動力資源硏究所誌 Vol.17 No.2

This thesis presents some results numerical experiments on the 2-D inversion of gravity data obtained in the structure models. The structure models are represented by their cross-sections of N-sided polygons with density contrasts which are varying with depths. Gravity data for the structure models are calculated by theoretical formulas and are regarded as the true observed gravity data. The inversion of the true data each model is performed by the damped least squares inversion method. Results of this study show that the subsurface interface and the surface density contrast of each model are accurately determined when the vertical density gradient is known. In cast where the density gradient is unknown, the inversion gives incorrect results. But the shape and the density gradient of the model are determined correctly when the surface density contrast is known as is the usual case. Correct inversion can be generally guaranteed by the following conditions; The initial assumption of unknown parameters such as the number of a polygon's vertices should be made reasonably. A way to estimate a reasonable initial model is to compare the objective function values obtained from various unknown parameters and to select the parameters corresponding to the minimum value.

프로와 아마추어 씨름선수들의 경쟁상태 및 특성불안에 관한 연구

이한우,육동원,고의석,김경수 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.1

The purpose of this study was to investigate differences of competition state anxiety (somatic state anxiety, cognitive state anxiety, and state self-confidence) and competition trait anxiety among three groups(highschool, university, and professional Korean Ssireum Players), and between winners and non-winners to analyze and evaluate the state of competition anxiety felt by players. Further more, This study present some useful guiding principles of effective coaching to improve the performance ability and control the competition anxiety of Ssireum players at fields. A total of 487 Ssireum players(204 highschool players, 206 college players and 77 professional players) participated in the SCAT and the CSAI-2 competition anxiety tests. Data were analyzed with One-way ANOVA and T-test. Results were as followings : College players showed significantly lower competition trait anxiety than highschool and professional players. Winner-group showed significantly lower competition trait anxiety than non-winner group. The three groups showed no statistically meaningful differences in the somatic and the cognitive state anxiety, but professional players showed significantly higher state self-confidence than highschool players. There were no differences in somatic state anxiety between winner group and non-winner group, but winner group showed significantly lower cognitive state anxiety and higher state self-confidence than non-winner group.

숯 처리에 의한 녹차 추출액 중 질산태질소 제거 효과

김진우,고영옥,신동국,이 협,전현식,이종옥 진주산업대학교 산업과학기술연구소 2005 산업과학기술연구소보 Vol.- No.12

This experiment was carried out to measure the elimination effect of nitrate nitrogen from green tea extracts through the column system filled with charcoal activated and bamboo charcoal powder compare to that of an nitrate nitrogen standard solution prepared with KNO3 chemicals. The change patterns of pH, and the amount of removed nitrate nitrogen from green tea and nitrate nitrogen standard solution were analyzed according to time course and the amount of charcoal treatments. The results were summarized as follow: 1. pH The pH of Green tea extractions treated with charcoal was high up to 8.17(after 30min treated with 0.4% charcoal) and 8.36(after 60min with 0.4% charcoal) which pH of non-treated green tea (control) was 5.8 The results indicated that the pH values were variable to the treated amount of charcoal and the teated time course. 2. Nitrate nitrogen From the nitrate nitrogen standard solution, the least rate 69.1% and the highest rate 74.5% of nitrate nitrogen were observed to be absorbed through the column treatment (60 min), which with green tea extract solution 21.3% (the least) and 43.8% (the highest) were detected to be absorbed through column treatment (after 60min with 0.4% charcoal). In the case of bamboo treatments with nitrate nitrogen solution samples were showed the least rate 62.8% (30min with 0.1% bamboo) and the highest rate 68.9% (60min with 0.4% bamboo), and with green tea extract solution were observed the least 13.6 (30min with 0.1% bamboo) the highest rate 29.4% (60min with 0.4% bamboo). In general, the elimination activity of nitrate nitrogen was higher by the charcoal activated powder treatment than bamboo charcoal.

급성사지허혈증에 대한임상적 고찰

김광한,권우형,이동식,서보양,권굉보 대한혈관외과학회 2003 Vascular Specialist International Vol.19 No.2

CNC 가공의 정밀 절삭 시뮬레이션 및 이송속도 스케줄링 시스템 개발

이한울,고정훈,조동우 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

This paper presents an accurate cutting simulation and feedrate scheduling system for CNC machining. This system is composed of a cutting simulation part and a feedrate scheduling part. The cutting simulation part computes the geometric informations and calculates the cutting forces in CNC machining. The cutting force model using cutting-condition-independent coefficients was introduced for flat end milling and ball end milling. The feedrate scheduling part divides original blocks of NC code into smaller ones with optimized feedrates to adjust the peak value of cutting forces to reference forces. Some machining examples show that the developed system can control the cutting force at desired levels.

3분 및 4분 상완골근위부 골절에서의 외반형 및 내반형에 따른 임상적 비교

최창혁,권굉우,김신근,이상욱,신동규,이승진 대한골절학회 2002 대한골절학회지 Vol.15 No.4

목 적 : 수술적으로 치료한 3분, 4분 상완골 근위부 골절을 외반형과 내반형으로 재분류하여 임상적 결과를 비교하고자 하였다. 대상 및 방법 : Neer 분류상 3분, 4분 상완골근위부 골절로 분류된 21례에 대해 수술적 치료를 시행하고 12개월 이상 추시된 증례를 대상으로, 골절부위의 각형성, 상완골두의 방향성, 그리고 우세 전위결절의 양상에 따라 외반형과 내반형으로 재분류하여 UCLA shoulder rating scale에 따른 기능적 평가를 시행하였다. 결 과 : 단순 방사선 소견을 기준으로 Neer의 3, 4분 상완골 근위부골절을 외반형과 내반형 및 각각의 아형(subtype)으로 분류할 수 있었다. 견관절 반치환술을 시술한 2례를 제외하고 분석한 각 그룹의 UCLA 기능적 평가는 외반형에서 양호 이상의 결과가 9례중 8례(89%), 내반형에서 10례중 4례(40%)로 외반형에서 더 우수한 임상적 경과를 보였다. 결 론 : 상완골 근위부 골절에서 골두의 방향성은 골절의 각형성 및 우세 전위결절의 양상과 높은 상관관계를 가졌으며, 내반형의 경우 혈행과 신경장애가 좀더 빈번하고 예후도 불량한 것으로 나타났고, 이러한 경우 수술시 도달 방법, 연부조직 상태에 대한 평가가 더욱 신중하게 고려되어야 할 것으로 생각되었다. Purpose : We reclassified three-and four-part proximal humerus fracture by Neer's classification into valgus & varus type, and compared the results of these groups. Materials & methods : 21 cases classified as three- and four-part fracture in Neer's classifiation were treated surgically and followed for 12 months. We reclassified the 21 cases vlagus and varus type fractures, according to angulation of fractures, facing of humeral head, and dominant displaced tuberosity. Functional evaluation was done by UCLA shoulder rating scale. Results : Neer's three- and four-part proximal humerus fractures could be reclassified based on angulation, facing of humeral head, and dominant tuberosity displacement. The functional results according to UCLA shoulder rating scale were good or excellent in 8 of 9 cases of valgus type(89%), and at 4 in cases of varus type(40%). The clinical result of the valgus type was better than that of the varus type. Conclusion : Based on reclassification system of proximal humerus fractures, clinical results and radiographic findings including angulation, facing of head and domonant tuberosity displacement showed close relationship. Neurovascular complication were more frequent in the varus type. Therefore, careful evaluation including surgical approach and soft tissue status should be considered in the varus type of complex proximal humerus fracture.