• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.6 s.109
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• pp.574-586
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• 2006

Recently radio communication environment have being standarded by the leading nations against the various technology of communication. Therefore to manage the changing communication environment, research about technology standard and standardization has gone variously in our country. In this dissertation, we discuss the trends of policy and analyze the technical regulation for the extremely low power devices in other countries. In addition, this paper proposes a draft revision of technical regulation for new efficient electric field strength of extremely low power devices in accordance with the technical requirement of Electromagnetic Compatibility. Based on these researches, the contents of this study will be useful to contribute a domestic efficient expansion and development of extremely low power devices and strengthen a competitiveness on international communication markets.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.9-15
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• 2010

This paper analyzed the problems of the Korean output regulation in the relevant band through an analytic comparison of the current trend of each country and their standard values concerning electric field strength (technical standard) of weak wireless stations with less than 135kHz. In connection with the standard value of electric field strength of each country, which has been proposed in the registration of the appropriate electric wave, the paper aims to propose the standard value of electric field strength that could actually be introduced for suitable unauthorized wireless devices (weak wireless devices) in Korea. Provided that the Korean standard may be upgraded based on the tolerances of electric field strength proposed m this paper, this is expected to be committed to the distribution and advancement of weak wireless devices; and further it is anticipated to be prepared with competitiveness not only in the Korean communications market, but also in the international communications market.

• Composites Research
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• v.19 no.3
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• pp.7-14
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• 2006

In this paper, an integrated probabilistic strength analysis was conducted to predict the reliability of a composite pressure vessel under inner pressure loading condition. As a probabilistic strength analysis, the probabilistic progressive failure model consisting of progressive failure model and Monte Carlo simulation was incorporated with a commercial FEA code, ABAQUS Standard, to perform the probabilistic failure analysis of composite structure which has a complex shape and boundary conditions. As design random variables, the laminar strengths of each direction were considered. Finally, from probabilistic strength analysis, the scattering of burst pressure could be explained and the reliability of composite pressure vessel could be obtained for each component. In case of composite structures in mass production, the effects of uncertainties in material and manufacturing on the performance of composite structures would apparently become larger. So, the probabilistic strength analysis is essential for the structural design of composite structures in mass production.

• Journal of the Korean Geophysical Society
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• v.2 no.3
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• pp.179-190
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• 1999

The overall structural framework was studied using the regional 2D seismic data, followed by the sequence stratigraphic study on the 3D seismic and well- log data in the margin of the South Con Son basin of the South China Sea. This research contributes to delineate depositional stratigraphy, depositional environment and geologic history in the 3D seismic area of highly complicated faulting. Eight Miocene sequences were indicated on the 3D seismic and well-log data, in which the structural maps of each sequence boundary and the isochron maps for the corresponding sequence were made. The seismic facies were analyzed for each sequence volume and sequence boundary surface. The 3D seismic area is characterized by coal beds deposited in the transgression environment (transgression systems tract) and channel distributions just above the sequence boundaries. During the Early Miocene, the coals and thick shales deposited in the mangrove swamp representing the lower coastal plain environment. During the Mid to Late Miocene, thick clastic sediments deposited in the coastal to shallow shelf by regional subsidence and marine transgression. The isochron maps and structural patterns indicate that the sediments were transported from west to east or from northwest to southeast.

• Journal of the Korean GEO-environmental Society
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• v.17 no.3
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• pp.27-35
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• 2016

Even if the various data analyzing methods were suggested to examine the measured slope behaviors, it is difficult to find methods or procedures for connecting the analyzed results of slope stability and measured slope data. This research suggests the analyzing methods combing the stability analysis and measured data based on progressive failure of slope. Slope failure analysis by time degradation were calculated by strength parameters composed of strength reduction coefficients, also which were compared to the measured data according to the variations of safety factor and displacement of slopes. The accumulated displacement curve were shown as 3rd degree polynomials by suggested procedures, which was the same as before researches. The reverse displacement velocity curves were shown as linear function for prediction of brittle slope failures, also they were shown as 3rd degree polynomials for ductile slope failures, which were the same as the suggested equation by Fukuzono (1985) and they were very similar behaviors to the in-situ failure cases.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.1
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• pp.96-109
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• 2019

As the role of universities as a civic university contributing to regional development has been emphasized, industry-academic cooperation projects are increasingly focused on quadruple helix interactions of university, government, business and civic society. Drawing upon focus group interviews, we divided place-based industry-academic cooperation projects into four different types and stages of development, according to two indicators of network participation and network strength. Although the proportion of projects that were in the early stages of development was overwhelmingly high, some universities developed a close cooperative system with the local community to enhance the effectiveness of the industry-academic cooperation projects and to implement them in an advanced stage. These findings suggest that the LINC+ project, which has been criticized for its policy effectiveness, will not only contribute to enhancing policy effectiveness through place-based projects but also enhance the role of universities as the main body of regional innovation.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.4
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• pp.349-360
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• 2008

In this paper, the modeling procedure of random field with an elasto-plastic finite element algorithm and probability of failure on closely-spaced tunnel were investigated. Local average subdivision (LAS) method which can generate discrete random variables fast and accurately as well as change the resolution in certain region was used. And correlated value allocating and weighted average method were suggested to implement geometrical characteristics of tunnel. After the probability of failure on the test problem was thoroughly investigated using random finite element method, the results were compared with the deterministic strength reduction factor method and single random variable method. Of particular importance in this work, is the conclusion that the probability of failure determined by simplified probabilistic analysis, in which spatial variability is ignored by assuming perfect correlation, can be estimated from the safety factor determined by strength reduction factor method. Also, single random variable method can lead to unconservative estimates of the probability of failure.

• Analytical Science and Technology
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• v.22 no.1
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• pp.57-64
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• 2009

A material database has been developed for VOCs and formaldehyde emitted from building materials in this study. New classification system has been made by correlating the classification methods used in Korean Air Cleaning and Environmental Protection Agency. The developed databases include emission rates of TVOC, 5VOC and formaldehyde emitted from each building material. In addition, the databases can be used as an input variable to estimate indoor air quality (IAQ) using computer simulation since they also contain chemical component and general imformation. Box plot was used to do statistical analysis for emission rates of formaldehyde and TVOCs from different types of building materials. Also we confirmed the building materials worsening IAQ by categorizing the emission characteristic of different types of pollutants.

• Journal of Korean Society of Steel Construction
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• v.11 no.1 s.38
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• pp.55-67
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• 1999

The ratios of elastic to shear modulus of the structures as laminated composite plates and shells, are very large. They are much susceptible to effect of shear deformation. In order to obtain the accurate solutions of laminated composite plate and shells, the effects of shear strain should be considered for the analysis and design of them. Especially, the more exact solution can be obtained in applying to higher-order shear deformation theory. Therefore, in this paper, the third-order shear deformation theory is used to present the distributions of bending, the characteristics of natural frequencies and the buckling load according to the effects of ply orientation, number of layers for the laminated composite plates and shells with simply supported boundary conditions.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.713-718
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• 2004

우리나라의 경우 재해영향평가 제도가 실시된 이후 모든 재해영향평가에서는 토양침식량을 산정하고 있다. 유역에서 토양침식량을 산정하기 위한 많은 모형들이 있지만, 분포형 모형들은 토양침식의 산정에 많은 비용과 시간을 요구한다. 그래서, 가장 널리 실무에서 쓰이고 있는 모형은 범용토양침식공식(USLE, Universal Soil Equation)이다. USLE은 연 토양 침식량 산정을 위한 경험공식으로, 토양침식은 강우강도, 토양의 종류, 토지 피복과 토지이용, 사면경사와 경사길이, 그리고 토양보전을 위한 시설의 영향을 받는다. 이러한 모든 변수들은 공간적으로 분포되어 있기 때문에, 이러한 변수들을 추정하기 위해 지형정보시스템(GIS)을 사용하면 보다 빠르고 정확한 변수들을 산정 할 수 있다. 또한, 유역에 내리는 강우는 토양침식뿐만 아니라 유기물의 흡착에 따른 비점오염원의 유출을 발생시킨다. 침식토에 흡착된 유기물의 양은 부유의 개념을 도입하여 산정 할 수 있다. 따라서 본 연구에서는 지형정보시스템(GIS)과 범용토양손실 공식을 연계하여 태풍루사의 강우에 의한 보청천 유역에서의 토양 침식량과 그와 함께 유출되는 유기질소(Organic N)의 양을 산정 하였다.