• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.2
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• pp.142-148
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• 2005

In this paper, the stress singularity on interface of friction welded dissimilar materials was investigated by using 2-dimensional elastic boundary element method. It is required that stress distributions and stress singularities on an interface for friction welded dissimilar materials analize to establish strength evaluation. The stress singularity index ($\lambda$) and stress singularity factor ($\Gamma$) were calculated from the results of stress analysis. The stress singularities on variations for shapes and thickness of friction welded flashes were analized and discussed. This paper suggested that the strength evalution by using the stress singularity factors as fracture parameters, considering the stress singularity on an interface edge of friction welded dissimilar materials were very useful.

• Journal of Biosystems Engineering
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• v.22 no.2
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• pp.227-236
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• 1997

Manual grading and sorting of red-ginsengs are inherently unreliable due to its subjective nature. A computerized technique based on optical and geometrical characteristics was studied for the objective quality evalution. Spectral reflectance of three categories of red-ginsengs - "Chunsam", "Chisam", "Yangsam" - were measured and analyzed. Variation of reflectance among parts of a single ginseng was more significant than variation among the quality categories of ginsengs. A PC-based image processing algorithm was developed to extract geometrical features such as length and thickness of body, length and number of roots, position of head and branch point, etc. The algorithm consisted of image segmentation, calculation of Euclidean distance, skeletonization and feature extraction. Performance of the algorithm was evaluated using sample ginseng images and found to be mostly sussessful.

• Analytical Science and Technology
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• v.5 no.2
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• pp.217-222
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• 1992

An attempt was made to analyze green microstructure of AIN samples prepared by slip casting and dry pressing through Hg-porosimetry. Slip cast samples with narrow pore size distribation and high packing density showed higher sinterability and homogeneous distribution of second phase(s). Hg-porosimetry is and effective way to determine pore structure if "ink bottle" phenomenon does not occur. A comparison study with porosity measurement by quantitative microscopy showed that the effectiveness of Hg-porosimetry measurement could be extended to higher sintered density as long as pores remained open.

• Korean Journal of Optics and Photonics
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• v.9 no.6
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• pp.396-402
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• 1998

The measurement of OTF(optical transfer function) is used for evalution of imaging performance of optical system as a standard method. In the mass-production, the contrast measurement of projected patterns is also popular because of its simplicity. In this study, a computer program which evaluates the CTF(contrast transfer function) of optical system for periodic line-space patterns is developed by using the diffraction imaging theory. The MTF(modulation transfer function) and CTF of an aberrated system are evaluated and analyzed for the third order aberrations expressed by the C-coefficients and the Zemike polynomials.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10a
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• pp.52-63
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• 2000

Many plant species are used in China in traditional medicine for the prevention and treatment of cancer. This paper presents some of these species with details on other pharmacologic evaluation and its traditional Chinese meditional uses. The known bioaktivities and some chemical constituents of each of the species given. Information on bioactivities of each species resulting from tests on experimental animals are given. Many of the known chemical constituents of each species are given. Various species of plants elective for various types. In this meeting I will present on some antitumor of the plants which are as follows; (1) Akebia trifoliata(Thunb.)Koidz. ((2) Panax notoginseng(Burk.) F, H, Chen., (3) Ziziphus jujuba Mill., (4) coriolus versicolor(Fr.)Que l., (5) Trichosanthes kirilowii Maxim., (6) Ficus carica Linnaeus., (7) Acanthopanax senticosus(Rupr.et Maxim.)Harms., (8) Hibiscus mutabilis Linnaeus., (9) Arctium lappa Linnaeus., (11) Agrimonia pilosa Ledebour and (12) Hedyotis diffusa Willd.

• Korean Journal of Human Ecology
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• v.7 no.2
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• pp.161-169
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• 1998

The purpose of this study is to find some major factors which can be used as basic design guideline for the elderly housing as the comfortable dwelling circumstances to keep life as self-reliant and secure as possible in their life. The subjects for this study were 200 elderly women in Taegu, data were collected through an individual visiting interview from 29th, Oct. to 15th, Nov., 1997. The major findings are as follows: 1) The elderly women preferred to live 30.3 pyung as the house size, and they desire to live with the married son's family in urban areas. 2) The evalution for the dwelling circumstance was unsatisfatory on the whole. All the preferred housing characteristics were different from the current housing characteristics. The comfortability of dwelling was least satisfied while the space size was most satisfied.

• Journal of the Korean Home Economics Association
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• v.31 no.4
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• pp.37-51
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• 1993

The Objects of this study are: 1. To compare the housework time of housewives by region and employment status. 2. To compare the economic value of housework by region and employment status. 3. To evaluate the economic value of housework by each method. The subjects of this study were 815 housewives living in Taegu and Kyungsangpookdo. The statistics used for data analysis were frequency, percentile, T-test, ANOVA and Seheffe test by SPSS PC programs: 1) The average housework time was 7.8hours per day. Full-time housewives spent 8.2hours and employed housewives spent 6.7hours to housework. 2) Partially there were significant difference in economic value of housework by employment status. 3) Estimates of economic value of housework by each method of evaluation are : (unit : won) sample mean method monthly (1) Specialized substitute method 587,080 (2) Overall substitute method 760,640 (3) Opportunity cost method 556,060 (4) Reservation wage method 534,070 (5) Subjective evalution method 644,540

• Journal of Pharmaceutical Investigation
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• v.25 no.4
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• pp.347-351
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• 1995

Antisense phosphorothioate oligodeoxynucleotide(PS-ODN) against $TGF-{\beta}$ was developed as scar formation inhibitor. The scar was caused collagen deposition due to overexpression of $TGF-{\beta}$ in wounded skin. The percutaneous absorption of partially modified PS-ODN(25 mer) was investigated for the purpose of its effective delivery. Though PS-ODN has high molecular weight (MW=8,000) and polyanionic charge, it was permeated through skin. The skin permeation of PS-ODN was markedly increased by the removal of stratum corneum and dermis. Moreover, the skin permeation of PS-ODN was decreased in the following order; hairless mouse skin>rat skin>human cadaver skin. Thus, PS-ODN represents a logical candidate for further evalution due to the potential for delivery into the wounded skin.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.483-490
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• 1997

The evalution of the cumulative distridution function of the noncentral $X^2$ distribution required in approxi-mate determination of the $X^2$ test. Many approximations to the cumulative distribution function of the noncentral $X^2$ distribution have been suggested. However, in selecting an approximations both simplicity and accuracy should be considered. In this note we compared various approximations in terms of accuracy and efficiency.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.201-215
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• 2003

At present, European railways in U.K., Sweden, and Belgium have taken serious efforts to improve railway services by implementing a service evaluation system. Not only do they measure the service-related performance of a railway system, but also operate an incentive system according to the results of service-related performance. This performance evaluation system can be also used to provide basic data for other policies such as fares, subsidies and track user charges etc. After the restructuring process of Korean national railways, therefore, although it is expected to face many difficulties in the future, it is desirable to implement a performance evaluation system for securing the long-term growth of Korean railway industry.