• 한국항공운항학회지
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• 제17권1호
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• pp.39-45
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• 2009

An Analysis of wind is essential for planning runway direction. As a general rule, the principal traffic runway at an airport should be oriented as closely as practicable in the direction of the prevailing wind. Aircraft are able to maneuver on a runway as long as the wind component at right angles to the direction of landing and taking-off, the cross wind component, is not excessive. ICAO recommends that runway be oriented so that aircraft may be landed at least 95% of the time with allowable cross wind components not exceeding specified limits based upon the airport reference field length. Based on the recommendation, the direction of the runway or runways at an airport can be determined through graphical vector analysis on wind rose. This study is to develop the wind-rose software for planning the optimum runway direction at an airport with the raw wind data based on reliable wind distribution statistics that extend over as long as a period as possible, preferably of not less than 5 years.

• 한국대기환경학회지
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• 제20권5호
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• pp.583-591
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• 2004

In this study, methodologies for the rational organization of air pollution monitoring network were examined by understanding the characteristics of temporal and spatial distribution of secondary air pollution, whose significance would increase hereafter. The data on $O_3$ and $NO_2$ concentrations during high ozone period in 1998~1999 recorded at the nine air pollution monitoring station in Busan were analysed using principal component analysis (PCA) and cumulative semivariogram. It was found that the ozone concentration was deeply associated with the daily emission characteristics or the $O_3$ precusors, and nitrogen dioxide concentration largely depends on the emission strength of regional sources. According to the spatial distribution analysis of ozone and nitrogen dioxide in Busan using cumulative semivariograms, the number of monitoring stations for the secondary air pollution can be reduced in east-west direction, but reinforced in north-south direction to explain the spacial variability. More scientific and rational relocation of air pollution monitoring network in Busan would be needed to investigate pollution status accurately and to plan and implement the pollution reduction policies effectively.

• Journal of the Korean Wood Science and Technology
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• 제17권4호
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• pp.70-76
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• 1989

The fracture toughness of two species, Pinus rigida MILL and Pinus koraiensis S. et Z. grown in Korea, was investigated by means of single edge notch beam specimen for the six principal systems of crack propagation in wood. The values of the fracture toughness for the LR and the LT systems ($K_{IC}$LR and $K_{IC}$LT) were found to be similar to each other and about 8 times greater than those for the other systems ($K_{IC}$RL, $K_{IC}$TL and $K_{IC}$TR) in both species. The results indicate that the characteristics of fracture toughness in three principal directions of wood (L, R, T direction) are quite different from those of bending strength for the responsible direction. To predict $K_{IC}$ value based on the variation of specific gravity, the experimental values of $K_{IC}$LT and $K_{IC}$TL were compared to the predicted values by published relationship between $K_{IC}$ and specific gravity. However, there were 10 to 25% differences between the former and the latter.

• 한국수산과학회지
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• 제28권1호
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• pp.1-6
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• 1995

1992년 7월 1일부터 8월 7일까지 득량만의 수문리와 득량도 사이의 수심 약 5m 되는 천go역에서 2.5m의 수심에 자기 기록식 유속계를 계류하여 유속관측을 하였고 이 자료를 분석하였다. 관측기간 동안 바람은 매우 약했으므로 조류의 성질을 연구하는 데 적합한 자료가 획득되었다. 항류성분은 0.8cm/sec의 속도로 남남동 방향으로 흐르며 이는 득량도 동부 수로를 통하여 북향류가 필요하고 따라서 반시계 방향의 느린 순환이 일어난다는 것을 암시한다. 조류의 주축 방향은 북북동-남남서 방향이며 전체 분산의 $98.7\%$가 이 방향에 집중되어 있다. 이 유속의 역학적 에너지의 $91.2\%$ 정도는 반일주조이며 일주조 이상의 장주기 성분은 $2.5\%$ 에 불과한 반면에 비선형효과에 기인하는 천해조 성분은 $6.3\%$ 정도를 점유하였다.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.107-115
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• 2001

It is required more precise analysis for practical load because of complexities and varieties of vehicle structure. To establish the numerical model, many researchers have been developed designing tools for linking F.E. Analysis results and experimental results. There studies have generally focused on each experimental method or analytical method separately. There are few studies based on both methods. This paper conceives new procedure for the determination of the load direction and magnitude applied on mechanical structures. New procedure is the combination of the analytical and empirical method with analyzed strain by F.E. Analysis under unit load and with measured principal stress by strain gages under driving load, respectively. In this paper, we theorize the procedure of practical load determination and make the validity and the practicality of the procedure with the application to T-shape jointed structure. F.E. Analysis is conducted to get the principal stress on arbitrary points in the F.E. model of T-shape joint under unit load. Then experiment is carried out to get the principal stress on the same points of F.E. model. To demonstrate the actual driving condition, the load conditions are bending and torsion. From these two data sets, the magnitude, the direction and the position of load can be obtained. Theory and practice do not always coincide; since there are some errors such as ill-poseness, measuring error and modeling error in experimental data, we examine the proper method of error minimization.

• 한국의류학회지
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• 제29권8호
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• pp.1168-1175
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• 2005

Clothing pressure has close relation with clothing comfort and depends on the pattern and properties of textile fabrics. Choosing a suitable clothing pressure is an essential factor for designing functional clothing such as the foundation for reshaping of a body contour or medical items for bum patient, and etc. However, it is hard to measure pressure values at the curved surface of a human body correctly. Recently, an air pack type pressure sensor, which has relatively excellent performance has been used to measure clothing pressure, however, it is still inconvenient to apply because it is a contact- type sensor. Therefore, in this paper, we suggest an indirect method that can measure clothing pressure without touching the subject by improving the equation of Kirk and Ibrahim (1966). However, confusions have been occurred when someone use the equation since the definition of parameters are somewhat vague. Furthermore, the estimated clothing pressure obtained by the previous method are quite different from the real values because this method does not consider the 3D effect of a human body and property changes of a transformed fabric. In this paper, the direction of principal stress and the radius of curvature in the principal direction were searched in the 3D image of the deformed girdle to get more accurate clothing pressure. The estimated clothing pressure was verified by comparing the result of the air pack type pressure sensor. It was found that the accuracy of the pressure estimation was improved by considering the 3D curvature of human body and the directional characteristics of textile fabrics.

• 한국작물학회지
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• 제58권3호
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• pp.267-273
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• 2013

본 연구는 강원도농업기술원 옥수수연구소에서 튀김옥수수 품종개발을 위하여 육성한 79개의 자식계통들에 대하여 총 13개의 양적 및 질적 형질들을 이용하여 형태적 변이 연구를 수행하였다. 3개의 질적 형질 중에서 웅수색(QL1)은 연한 자주색을 나타내는 계통(46계통)들이 가장 많았고, 자수색(QL2)과 줄기색(QL3)에서는 각각 녹색을 나타내는 계통(55계통, 75계통)들이 가장 많았다. 반면에 10개의 양적형질 중에서 간장(QN1)은 $174.2{\pm}34.9$ cm, 착수고(QN2)는 $103.4{\pm}24.7$ cm, 이삭장(QN3)은 $9.4{\pm}3.0$ cm, 착립장(QN4)은 $8.4{\pm}2.6$ cm, 이삭경(QN5)은 $24.9{\pm}7.7$ mm, 이삭열수(QN6)는 $14.0{\pm}2.3$ 열, 이삭중(QN7)은 $36.5{\pm}26.0$ g, 종실중(QN8)은 $30.9{\pm}19.3$ g, 백립중(QN9)은 $10.4{\pm}3.8$ g, 발아율(QN10)은 평균 $95.3{\pm}8.1%$를 각각 나타내었다. 분석에 이용된 자식계통들 중에서 5개의 자식계통(PS0-001, PS0-003, PS1-002, PS1-003, PS2-009)들은 조사된 7개의 수량 관련 형질들 중 5개 이상의 형질들에서 비교적 높은 경향이었다. 주성분 분석은 분석에 이용된 13개의 양적 및 질적 형질들 중에서 자수색(QL2), 이삭장(QN3), 착립장(QN4), 이삭경(QN5), 이삭중(QN7), 종실중(QN8), 백립중(QN9)은 제 1 주 성분에서 양의 방향에 크게 기여하였고, 반면에 웅수색(QL1), 줄기색(QL3), 착수고(QN2) 그리고 이삭열수(QN6)는 음의 방향에 크게 기여하였다. 제 2 주성분에서는 간장(QN1), 착수고(QN2) 그리고 종실중(QN8)은 양의 방향에 크게 기여하였고, 반면에 웅수색(QL1), 자수색(QL2), 이삭장(QN3), 이삭열수(QN6) 그리고 100립중(QN9)은 음의 방향에 기여하였다.

• 한국식품과학회지
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• 제28권6호
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• pp.1171-1176
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• 1996

레토르트 살균처리시 일어나는 계육 모형식품의 휘발성분 변화를 GC 및 GC-MS로 분석한 후 그 데이터를 활용하여 통계분석을 행하였다. 먼저, 분산분석으로 통계적으로 유의한 42개 peak를 선택하였으며 이를 독립변수로 하여 다변량 통계분석을 실시하였다. 단계적 판별분석법으로 두 시료집단의 차이를 명확히 구분하는 GC peak로서 2-heptanone 등 8개 peak를 순차적으로 얻었다. 이어서 선택된 8개 peak를 독립변수로 주성분 분석을 한 결과, 3개 주성분으로, 96.1%의 높은 판별이 가능함을 알 수 있었으며, 특히 PC1은 76.5%의 판별이 가능한 것으로 나타났다. 또한, 주성분을 이용한 요인분석(Factor Analysis)을 행하여 8개 peak 상호간의 관계를 검토한 결과 11, 20, 21번 peak는 그 방향성 및 크기가 거의 같았으며, 11, 20, 21번 peak 그룹과 9, 32, 39번 peak 그룹은 방향성이 서로 반대이며 크기도 매우 큰 것으로 밝혀졌다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 춘계학술대회 논문집
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• pp.268-273
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• 1992

Thin walled tubular specimens of 0.45% structural carbon steel were used in the bizxial tests. Biaxial fatigue tosts were conducted on strain control including fully reversed tension-compression and in phase tension torsion loadings. The predictions of the biaxial fatigue life were based upon the uniaxial low cycle fatigue test results. Fatigue lives were ranged from 10$\^$2/to 10$\^$5/cycles. Four multiaxial strain based theories have been developed to correlate biaxial fatigue experimdntal results. These theories showed good correlatins except for maximum shear strain theory. In uniaxial tests, crack behavior was observed that crack initiated in the maximum shear strain direction and propagated in the direction perpendicular to principal stross. But, in biaxial tests, both crack initiation and growth occured on the maximum shear strain direction only.

• Journal of the Optical Society of Korea
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• 제15권1호
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• pp.15-21
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• 2011

This paper proposes a new approach to palmprint verification based on the gradient, in which a palm image is considered to be a three-dimensional terrain. Principal lines and wrinkles make deep and shallow valleys on a palm landscape. Then the steepest slope direction in each local area is first computed using the Kirsch operator, after which an orientation map is created that represents the dominant slope direction of each pixel. In this study, three orientation maps were made with different scales to represent local and global gradient information. Next, feature matching based on pixel-unit comparison was performed. The experimental results showed that the proposed method is superior to several state-of-the-art methods. In addition, the verification could be greatly improved by fusing orientation maps with different scales.