• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.1
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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.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.5
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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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• v.17 no.4
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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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.1
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• pp.1-6
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• 1995

A recording current meter was deployed in the shallow western part of Deukryang Bay from 1 July to 7 August 1992 during which the wind was weak. Principal component in NNE-SSW direction parallel to the axis of the bay had $98.7\%$ of the total variance and the orthogonal component of only $1.3\%$. Spectral analysis of the principal component revealed that the semidiurnal component comprised about $91.2\%$ of total energy. Whereas the diurnal and longer components were less than $2.5\%$ the shallow water tide was about $6.3\%$ . Weak mean current of 0,8cm/sec in SSE direction implies that the slow circulation in the bay is counterclockwise having the northward net flow in the deep eastern part.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.2
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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.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.8 s.145
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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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.3
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• pp.267-273
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• 2013

We evaluated the morphological characteristics of 79 popcorn inbred lines, which were developed to breeding popcorn variety at Maize Experiment Station, Gangwon Agricultural Research and Extension Services, by examining ten quantitative and three qualitative characteristics. In the survey of 3 qualitative traits for 79 popcorn inbred lines, most inbred lines respectively showed purple (46 inbred lines) at tassel color (QL1), green (55inbred lines) at silk color (QL2) and green (75 inbred lines) at stem color (QL3). While, on the survey of 10 quantitative traits among 79 popcorn inbred lines, they showed the morphological variation in plant height (QN1, $174.2{\pm}34.9$ cm), ear height (QN2, $103.4{\pm}24.7$ cm), ear length (QN3, $9.4{\pm}3.0$ cm), kernel setting length (QN4, $8.4{\pm}2.6$ cm), ear thickness (QN5, $24.9{\pm}7.7$ mm), ear row number (QN6, $14.0{\pm}2.3$ number), ear weight (QN7, $36.5{\pm}26.0$ g), kernel weight (QN8, $30.9{\pm}19.3$ g), 100 kernel weight (QN9, $10.4{\pm}3.8$ g) and germination rate (QN10, $95.3{\pm}8.1%$), respectively. As a result, 5 inbred lines (PS0-001, PS0-003, PS1-002, PS1-003, PS2-009) in the 79 popcorn inbred lines have showed comparatively high values for the five quantitative traits. On the principal component analysis, silk color (QL2), ear length (QN3), kernel setting length (QN4), ear thickness (QN5), ear weight (QN7), kernel weight (QN8) and 100 kernel weight (QN9) greatly contributed in positive direction on the first principal components, whereas tassel color (QL1), stem color (QL3), ear height (QN2) and ear row number (QN6) contributed in negative direction on the first principal component. In addition, plant height (QN1), ear height (QN2), and kernel weight (QN8) contributed in positive direction on the second principal component, and also tassel color (QL1), silk color (QL2), ear length (QN3), ear row number (QN6) and 100 kernel weight (QN9) contributed in negative direction on the second principal component.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1171-1176
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• 1996

The changes in volatiles of the model system were analyzed by GC and GC-MS before and after retorting. The GC data were analyzed statistically by applying the analysis of variance, and 42 peaks were selected at 5% significance level. Multivariate statistical analysis was performed with these 42 peaks as independent variables. Through the stepwise discriminant analysis, 8 peaks, which corresponded to the compounds such as 2-heptanone, cis-3-hexenal, 2-pentyl-furan, 1-methyl-trans-1,2-cyclohexanediol, 2-hexanone, 3-octanone, trans, trans-nona-2,4-dienal and 1-octen-3-ol, were obtained in sequence to distinguish the samples with and without retorting. The principal component analysis of a set of 8 independent variables resulted in 3 principal components which accounted for 96.1% of the variance, while the first principal component (PC 1) explained 76.5% of the total variance. In addition, through the factor analysis of the principal components, the peaks 11, 20 and 21 could be grouped togather in accordance with the direction and the size while the peaks 9, 33 and 39 constituted the second group in the direction.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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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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• v.15 no.1
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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.