• The Korean Journal of Applied Statistics
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• v.18 no.2
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• pp.421-434
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• 2005

Machine learning has been extensively studied in recent years as effective tools in pattern classification problem. Although there have been several approaches to machine learning, we focus on the mathematical programming (in particular, multi-objective and goal programming; MOP/GP) approaches in this paper. Among them, Support Vector Machine (SVM) is gaining much popularity recently. In pattern classification problem with two class sets, the idea is to find a maximal margin separating hyperplane which gives the greatest separation between the classes in a high dimensional feature space. However, the idea of maximal margin separation is not quite new: in 1960's the multi-surface method (MSM) was suggested by Mangasarian. In 1980's, linear classifiers using goal programming were developed extensively. This paper proposes a new family of SVM using MOP/GP techniques, and discusses its effectiveness throughout several numerical experiments.

• Korea journal of population studies
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• v.33 no.1
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• pp.161-189
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• 2010

Dealing with uncertainty has been a critical issue in demographic and population forecasting since 1980. This study reviews methodological developments in demographic and population forecasting over the last several decades. First, this study reviews the important issue of the uncertainty surrounding demographic forecasts. Several limitations of the traditional scenario approach to dealing with uncertainty are also discussed. Second, in forecasting demographic processes such as mortality, fertility, and migration, three approaches of stochastic forecasting are identified and discussed: expert judgment, statistical modeling, and analysis of historical forecast errors. Finally, this study discusses the current issues and directions for future research in stochastic demographic forecasting.

• Journal of the Korea Concrete Institute
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• v.14 no.2
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• pp.257-265
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• 2002

Porous concrete has good permeability sine it contains about 10∼20 ％ of voids, had has been introduced to korea in early 1980's. It, however, has problems such as a lack of optimized mixture, low strength and durability, and etc. It is thus Interesting to manufacture high-performance porous concrete satisfying the mechanical characteristics to be supplied In practical construction. The results of this study were as follows : the compressive strength was 132∼221 kgf/$\textrm{cm}^2$, the splitting tensile strength was 15∼25 kgf/$\textrm{cm}^2$, the flexural strength was 36∼54 kgf/$\textrm{cm}^2$, and the coefficient permeability was 1.05${\times}$10$\^$-1/ ∼ 9.20${\times}$10$\^$-2/ cm/sec. In order to change the maximum size of aggregate, It is believed that other mixtures should be studied further.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.45-59
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• 2014

Real estate has been the most preferable investment asset since 1980's has begun. Especially the ups and downs of housing price influence significantly on the household and national economy for a digital economy. In this analysis, monthly movement of apartment price of Seoul and its correlation with KOSPI, construction concerned shares, securities concerned shares, interest rate and exchange rate for 320 months(from January, 1987 to August, 2013) are shown. From the analysis, correlation coefficient of the price of apartment in Seoul and KOSPI is 0.8566 which is highly positive while the price of apartment in Seoul and interest rate are shown strong negative correlation which is -0.7846. The rise of stock market does affect the rise of the price of apartments in Seoul, on the contrary, the price goes down when the interest rate goes up.

• Economic and Environmental Geology
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• v.39 no.4 s.179
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• pp.427-440
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• 2006

Electromagnetic(EM) survey has been in use for over a half century as a standard routine for, mineral exploration in many parts of the world. But EM survey work and serious research effort were initiated in Korea only as late as in early 1980s, largely inspired by four pioneers who did their graduate studies in the U.S.A. in 1970s. Nevertheless domestic achievements in the field of EM survey are remarkable in the last two decades: the field operations and related interpretational skills appear to have reached a global standard, even compared with the most advanced in other countries, virtually in a whole spectrum of the method which includes magneto-tellurics(MT), Controlled Source Audio-frequency Magneto-tellurics(CSAMT), geomagnetic sounding, small loop survey systems, Very Low Frequency(VLF), Ground Penetrating Radar(GPR), time domain surveys, and noise analysis. Besides mineral exploration, EM survey has been applied in Korea to hydrogeology, geotechnical engineering, non-destructive investigation of structures, unexplored ordnance(UXO) investigation, environmental monitoring, and archaeological investigation as well. Now that original contributions of several Korean geophysicists are found even in new frontiers such as high-frequency EM survey, investigation in time-domain EM field for buried metal objects and structures, and also modem data inversion scheme, it is duly hoped that they make some technical breakthrough to unravel still entangled knots of EM survey method in a forseeable future.

• Archives of design research
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• v.17 no.4
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• pp.5-14
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• 2004

Black and white TV design process at early electronics industry can help greatly in strategy of forward product development or production and marketing. Because, there is history about existed all product to precess that progress. Past information make good use that estimate of new design. According to character of product, advertisement and business strategies are available some extension of life cycle or preservation. But, it is need the data accumulated with correct analysis for ability that competitive power of the product. Data of Past information take advantage of well information is essential. Information about past products arranged pamphlet and newspaper advertisement. At this study emphasized on console model TV and portable style TV design change process of technology ability from 1960s to 1980s about product selling point. Creation and extinction about products can get into iteration to other household electric appliance. Design process of past product design has a history with our international location or influence power of household electric appliance. Therefore, such past flowing can important role as basis of forward product design.

• Journal of Engineering Education Research
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• v.10 no.1
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• pp.86-96
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• 2007

The purpose of this study is to investigate and to display circumstances about importance issues connected with various publication data and engineering ethic principle. It is an investigation study about circumstance and actual conditions of engineering ethics education that is spoken by engineering ethics or engineer ethics on present Japan. Engineering ethics principle, or engineer ethics education is continued until present appearing in the 1980s by formal course of study in the case of American university. But, in the case of Japan, along with appearance of JABEE (Japanese Accreditation Board for engineering education), engineering ethics education for engineer is proceeded very intensively. At present, the purpose of engineering ethics education is heard on important engineering literary category so much so that can emphasize very as basic attitude to prepare everybody if it is a person who is to be an engineer. The present condition and circumstance of Japanese engineering ethics education analysis may become good information in the beginning step on ethics principle education of engineering our country.

• Journal of Astronomy and Space Sciences
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• v.9 no.1
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• pp.41-51
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• 1992

Photoelectric observations of close binary stars, AO Cam and AW Cam, were made during the 1984 observing season with the 61cm reflector at the Sobaeksan Observatory. One time of primary minimum for AO Cam and three primary epochs for AW Cam were derived from the observations of these two systems. Times of minimum light of these two binaries collected from literature were analyzed with a least square fitting method. New improved light elements for AO Cam and AW Cam were determined. The orbital period of AO Cam had been constant from Octobar, 1980 (JD 244520) to February, 1985 (JD 2446107). However, one secondary time of minimum (JD 2447864.7879) of AO Cam published recently by Mullis and Faulkner(1991) shows large deviation of about 4.6 minutes ($0^d.0032$) from the one predicted by our new light elements. Future observations of times of minima for this system are needed to test this period change. The orbital period of AW Cam has been constant as P=$0^d.77134645$ for about sixty years from the early 1930's to the present.

• Journal of the Korean Geographical Society
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• v.44 no.6
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• pp.675-690
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• 2009

This paper aims to analyze number of Asian dust days and their controlling factors in Korea. Asian dust days, Arctic oscillation index, Antarctic oscillation index and Eurasian snow cover data were used in this study. The number of Asian dust days was increasing after the middle 1980s. The number of Asian dust days was concentrated in April. The number of Asian dust days was increased second half (5.1 days) than first half (3.2 days) of the study period. The number of Asian dust days had positive relationship with winter Arctic oscillation index and Antarctic oscillation index. When the Arctic oscillation index and Antarctic oscillation index is positive, the Asian dust days will be increased. The number of Asian dust days had negative relationship with the Eurasian snow cover. When the Eurasian snow cover will be decreased, the Asian dust days will be increased.

• Archives of design research
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• v.15 no.3
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• pp.191-200
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• 2002

In the 1980s, even though Italy faced economic depression, Italy (she), now, internationally became a strong nation with its best design by national unity and the developmental leap of industry through design. In Italy, especially, small and medium enterprises are accumulated by the same business in each area on the structure of a Cluster system. Italy has some characteristics that being the Italians' elastic way of management, family management and development of a consortium of small and medium enterprises, which have flexibility, imagination and decisiveness. We have to bring these intensified factors of design competitiveness to our country so that we should form the union in order to have a monopoly of specific enterprises based on the specialized technology of small and medium enterprises innovating the structure of a small quantity production having developmental flexibility. We also heighten the sense of designer and publics by achieving social opinion and cult! ural revival. Moreover, the mind of managers has to be changed more aggressively. Finally, the actual policy of design will be established and peformed, and design-company (enterprises) and the industrial economy will generally develop when we activate the structure of the industry centered on small and medium enterprises and design-related association that is united and participates in the establishment of design policy.