• 보존과학연구
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• s.8
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• pp.1-12
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• 1987

Fifty ancient Korean coins originated in Choson dynasty have been determined for 9 elements such as Sn, Fe, As, Ag, Co, Sb, Ir, Ru and Ni by instrumental neutron activation analysis and for 3 elements such as Cu, Pb, and Zn by atomicalsorption spectrometry. Bronze coins originated in early days of the dynasty contain as major constituents Cu, Pb and Sn approximately in the ratio 90 : 4 : 3, where as, those in latter days contain in the ratio 7 : 2 : 0. Brass coins which had begun in 17century contain as major constituents Cu, Zn and Pb approximately in the ratio 7 : 1: 1. The multivariate date have been analyzed for the relation among elemental contents through the variance-covariance matrix. The data have been fur theranalyzed by a principal component mapping method. As the results training set of 8class have been chosen, based on the spread of sample points in an eigenvector plotand archaeolgical data such as age and the office of minting.

• Journal of the Korean Institute of Landscape Architecture
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• v.15 no.2
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• pp.101-113
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• 1987

The landscape structure of the both pre-industrial and industrial cities should be influenced to the topographical feature , religious thoughts, political ruling system and history. In the major socio-cultural factors in the pre-industrial townscapes in korea, the Feng - Shui(poongsu) which is an acient human settlement organization system based on the “Yin - Yang” principle and “Five Elements” and “Chryaegogong”system were the most important factors to the formation of traditional town scape in Korea. The landscape during the Japanese colonial periods were basically reorganized through change of “Boundary”, “Center” “Direction(path)” and “Domain” which were expressed by distinct traditional townscape in Yi dynasty. The physical shapes, meanings and behaviors of townscape were expressed properly of the intention of the colonization. As changes to the mordern industrial cities, the townscape had been amended landscape elements of the Japanese imperialism to an ideology of rebirth nation. Also as changes to the modern industrial cities, “Boundary”, “Center”, and “Domain” spreaded into the suburbs by funtionalsm and these were expressed an incoherent value system which were the advancement of growth, pursuit policies as well as an advancement of science techniques.

• International Journal of Contents
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• v.6 no.1
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• pp.12-19
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• 2010

In this paper, attendance in distance learning courses of a cyber university has been surveyed in an effort to verify the effectiveness of distance learning. Based on survey data from 4,749 distance learning participants, major attending place, major reasons for attending online class, fidelity to online classes, attending time per week, perceived educational effectiveness, perceived and relative seriousness of problems, and other variables have been evaluated. The results indicate that perceptional seriousness of the investigated problems is not statistically important. The findings indicate that, among operational problems, self willingness and cheating are the most remarkable. In contrast, the relative seriousness of traditionally recognized problems such as H/W availability and network speed among environmental problems is least remarkable. An analysis of demographic differences such as sex, employment, and school year in terms of seriousness of problems is also performed. The results reveal the existence of statistically significant differences according to sex, employment, and school year with regard to almost all elements of environment, actual current conditions, and seriousness of problems, with the exception of some elements such as attending place and perceived fidelity.

• Journal of Environmental Science International
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• v.27 no.3
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• pp.227-231
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• 2018

We studied the warming effect induced by Photovoltaic(PV) power plants in rural areas during summer daytime using a simple analytical urban meteorological model. This analysis was based on observed meteorological elements and the capacity of the PV power plant was 10 MWp. The major axis length of the PV power plant was assumed to be 1km. Data of the necessary meteorological elements were obtained from a special meteorological observation campaign established for a over a PV power plant. We assumed that the wind flowed along the major axis of the PV power plant(1 km). As a result, the air temperature on the downwind side of the PV power plant was estimated to invrease by about $0.47^{\circ}C$.

• Journal of Korea Technology Innovation Society
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• v.8 no.3
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• pp.1175-1198
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• 2005

The objective of the study is to verify the relationship between technology valuation indexes and corporate's performance in ventures by business operating periods. The result of the study is expected to be useful in loan evaluation, investment decision, internal management decision making and business improvement. The results of study is as follows. First, in early stage ventures, we find that three major valuation index(technology feasibility, economic efficiency, productivity) are significant ex-ante variables which are discriminating between firms' going concern and firms' failure. Second, in growth stage ventures, we find that three major valuation index(business feasibility, general marketability, technology marketability) are significant ex-ante variables which are discriminating between firms' going concern and firms' failure. Third, in early stage ventures, we find that at least thirty-eight minor valuation index elements are significant ex-ante variables which are discriminating between firms' going concern and firms' failure and in growth stage ventures, thirty-one minor valuation index elements are significant in various analysis' results.

• Journal of Soil and Groundwater Environment
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• v.23 no.5
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• pp.37-44
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• 2018

Soil trace elements and their bioaccumulation in agricultural products have attracted widespread concerns, yet the crop uptake characteristics of trace elements in different soil-plants systems have been rarely investigated. Experiments were carried out to investigate the effect of soil properties on trace element concentrations in cabbage and radish. Soil pH and total organic matter were major factors influencing trace elements transfer from soil to vegetables. Inclusion of other soil properties in the stepwise regression analysis improved the regression models for predicting trace element concentrations. Consideration of other soil properties should be taken into account for more precise prediction of trace element concentrations in the two vegetables, which could help quantitatively evaluate the ecologic risk of toxic trace elements accumulation in crops.

• Genomics & Informatics
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• v.5 no.4
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• pp.179-187
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• 2007

An increasing number of primate genomes are being sequenced. A direct comparison of repeat elements in human genes and their corresponding chimpanzee orthologs will not only give information on their evolution, but also shed light on the major evolutionary events that shaped our species. We have developed REPEATOME to enable visualization and subsequent comparisons of human and chimpanzee repeat elements. REPEATOME (http://www.repeatome.org/) provides easy access to a complete repeat element map of the human genome, as well as repeat element-associated information. It provides a convenient and effective way to access the repeat elements within or spanning the functional regions in human and chimpanzee genome sequences. REPEATOME includes information to compare repeat elements and gene structures of human genes and their counterparts in chimpanzee. This database can be accessed using comparative search options such as intersection, union, and difference to find lineage-specific or common repeat elements. REPEATOME allows researchers to perform visualization and comparative analysis of repeat elements in human and chimpanzee.

• Interaction and multiscale mechanics
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• v.3 no.3
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• pp.235-255
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• 2010

This paper investigates the heat equation for domains subjected to an internal source with a sharp spatial gradient. The solution is first approximated using linear finite elements, and sufficiently small time-step sizes to yield stable simulations. The main area of interest is then in the ability to approximate the solution using Generalized Finite Elements, and again explore the time-step limitations required for stable simulations. Both high order elements, as well as elements with special enrichments are used to generate solutions. When compared to linear finite elements, the high order elements deliver better accuracy at a given level of mesh refinement, but do not offer an increase in critical time-step size. When special enrichment functions are used, the solution can be approximated accurately on very coarse meshes, while yielding solutions which are both accurate and computationally efficient. The major conclusion of interest is that the significantly larger element size yields larger allowable time-step sizes while still maintaining stability of the time-stepping algorithm.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.10a
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• pp.62-62
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• 1998

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.788-793
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• 1995

For a linkage mechanism deiven by cam, cam profile is the major design factor and is determined by the motion type od cam follower. If a cam mechanism has additional kinematic linkages besides cam and follower then the follower motion should be specified form the motion of end linkage member so that cam would be able to generate the desired end linkage motion. In this paper, a cam-linkage mechanism is constructed with the combinations of modular linkage elements including cam and follower and as a resullt, a planar cam-linkage mechanism design software with the cam profile optimization function is developed and presented.