• Journal of Astronomy and Space Sciences
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• v.4 no.1
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• pp.47-54
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• 1987

Earth currents with 10~20 ${\mu}A$ flow due to a magnetic induction by large currents flowing through the ionosphere. In order to measure the behaviour of ionosphere indirectly, earth currents will be measured and the results will be reported.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.674-679
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• 2006

The public research and development (R&D) funds for construction engineering is one of the key elements for the advancement of construction industry. Korean Ministry of Construction and Transportation is currently planning to produce approximately US$ 500 millions of research funds every year in Korea from year 2007. Along with the prospect for increasing R&D investment, there is of increasing pressures on the development of quantitative methodologies for assessing the performance of construction R&D results. Although there have been some general R&D project evaluation methods, they are not readily used for construction R&D research assessment due to the distinct characteristics of construction R&D. This paper presents a simple methodology that can make quantitative assessments of construction R&D performances. The proposed methodology is expected to assist government officials in objectively evaluating construction R&D performances and identifying the areas that require more R&D investment.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.799-812
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• 2017

Backfill grouting and realistic convergence distribution were not properly considered in previous studies on 2D numerical analysis of a shield TBM tunnel. In this study, a modeling method was suggested to cope with this problem by considering a realistic convergence distribution and proper properties of backfill grouting. To this end, the influence of gap parameter and depth of rock cover on volume loss and composed of ground volume loss around tunnel excavation and surface volume loss were analyzed with a single layer of weathered soil. As a result, most of surface settlements were occurred immediately after excavation. Additional, as depth of rock cover and gap parameter increased, the influence range of surface settlement curves obtained from 2D numerical analyses became broader than a suggested theoretical equation. Therefore, it is inferred that gap parameter should be applied based on load distribution ratio and the property of backfill grouting properly considered for the estimation of the precise behavior of a shield TBM tunnel in 2D numerical analysis.

• Journal of Korea Technology Innovation Society
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• v.9 no.1
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• pp.26-51
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• 2006

Recently technology commercialization has been the focus of technology Promotion Policy in Korea. This paper tries to develop a composite indicator for measuring trends and prospects of national technology commercialization through integrating large amount of information into easily understood formats. The indicator is composed of five sector indicators including activity, cooperation or networking, performance, environment, and psychology indicators, each of which aggregates five individual variables. The statistical method of standardizing and weighting variables in the aggregation process are also mentioned. This indicator is expected to be a useful monitoring and policy tool for the Korean technology market.

• Geophysics and Geophysical Exploration
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• v.5 no.3
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• pp.185-192
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• 2002

We made a study of 3-D migration which could precisely image data of GPR (Ground Penetrating Radar) applied to NDT (Non-Destructive Test) field for the inspection of structural safety. In this study, we obtained 3-D migrated images of important targets in structuresurvey (e.g. steel pipes, cracks) by using 3-D Kirchhoff prestack depth migration scheme developed for seismic data processing. For a concrete model consisting of steel pipe and void, the targets have been well defined with opposite amplitude according to the parameters of the targets. And migrated images using Parallel-Broadside array (XX configuration) have shown higher resolution than those using Perpendicular-Broadside array (YY configuration) when steel pipes had different sizes. Therefore, it is required to analyze the migrated image of XX configuration as well as that of general YY configuration in order to get more accurate information. As the last stage, we chose a model including two steel pipes which cross each other. The upper pipe has been resolved clearly but the lower has been imaged bigger than the model size due to the high conductivity of the upper steel.

• The Journal of the Acoustical Society of Korea
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• v.7 no.2
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• pp.20-25
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• 1988

This study is to explain the characteristic of excess attenuation on the ground through the outdoors experiment about noise propagation and the reduced model experiment of acoustic. The outdoors experiment on the attenuation of noise propagation was tried with the small engine that had large acoustic output, and then it was conformed that there was relationship between the excess attenuation calculated by measurement from distance attenuation and Log(D/(Hs+Hr)). As a result, it was found that the attenuation of noise propogation depended upon the direction of the wind and frequency and was regressed in a straight line. And the numerical values of excess attenuation on the ground could be calculated by regarding Log(D/(Hs+Hr)) as a parameter with an airing resistance $\sigma$. It was found that when the mean square error between the excess attenuation calculated by measurement and the value calculated by a fomula $L=-20Log\mid1+(r_1/r_2)Qexp(ik, \bigtriangleup r)\mid$ about optional $\sigma$ was least, the optimal decision of u was made. As the characteristic of model is the model experiment on a reduced scale of 1 to 40, It was conformed that it corresponds enough with the measurement value with measuring the distance attenuation in the large anecoic chamber.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.4
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• pp.312-320
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• 2016

This study analyzed the distribution of the blood glucose level according to the fasting status. Moreover, a relationship was analyzed between fasting blood glucose level and glycemic control indicators. A total of 707 outpatients, who visited Dankook University Hospital, were included and classified into either the fasting group and the non-fasting group. The mean blood glucose level of each group was calculated and analyzed by sex, age, and clinic. In addition, blood glucose, HbA1c, fructosamine, and 1,5-AG were measured in 153 fasting health check-up patients, and the correlation between the blood glucose level and glycemic control indicators was evaluated. Blood glucose averages between the two groups (non-fasting 111.9 vs. fasting 103.6 mg/dL) were different (p<0.05); and the mean difference was lower in women (4.8 mg/dL) than in men (12.2 mg/dL). A significant difference of the median glucose values among the age groups was only observed in the non-fasting group (Kruskal-Wallis test, p<0.01), and not in the fasting group. A 1,5-Anhydroglucitol was estimated to be significantly correlated with the fast blood glucose level in the range of the criteria of impaired fasting glucose (IFG). We presented an assessment of the distribution of blood glucose level in accordance with the fasting status among outpatients, and estimated that 1,5-anhydroglucitol was well correlated with the fasting blood glucose than fructosamine and HbA1c, through the analysis of results of health screening subjects. It is suggested that the use of glycemic indicators that reflect short-term blood glucose control can be used together with the blood glucose measurement in the screening of diabetes mellitus.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5D
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• pp.697-703
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• 2011

Studies have shown that research and development has positively impacted the upbringing of construction industry. However, its economic effect has not yet been fully investigated. This study develops an economic effect analysis model for R&D performance. In-depth interview and review of the literature produced a total of 11 performance indicators that considered the public characteristics of construction industry. A case study which involved the Expressway & Transportation Research Institute was conducted in order to verify the proposed model. The result showed that the return on investment of the institute was 3.3 times of the R&D investment. The proposed model is expected to help researchers analyze an economic effect analysis model for R&D performance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4D
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• pp.335-343
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• 2012

In the study, evaluation indicators that should be considered in applying traffic calming schemes were developed, and it was intended to analyze the importance of indicators that should most considered in evaluation traffic calming scheme through AHP analysis on the basis of it. The result of the study is summarized as follows. The result of evaluation indicators may be summarized by dividing into residential area and commercial area. In category, the safety is shown to be more important than other indicators in the analysis when evaluation (residential area is 0.514 and commercial area is 0.439). Importance of evaluation indicators was analyzed in order Average Vehicle Speed, Traffic Accident Severity, and Pedestrian Separation. Residential areas to help keep the safety of pedestrians 'Average Vehicle Speed' as the major indices were derived. In commercial areas were analyzed as an important indicator Pedestrian Separation. Because there are so many pedestrians. When applying the effect of Traffic Calming, residential is greater than the commercial area.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4D
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• pp.547-553
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• 2011

This study has redefined the concepts of mobility indexes and potential demand, standards to evaluate areas with the worst public transportation system and applied the relevant indexes to select the areas with the worst public transportation mobility and present a method to set direct public transportation lines between these regions. The mobility indexes and indexes to evaluate potential demand were applied to select the regions with the worst public transportation systems in four metropolitan cities and case studies were carried out on direct lines provided between these regions. The analysis results showed that in public transportation mobility blind spots, public transportation takes much longer than driving an automobile or public transportation services are not provided. In addition, the analysis showed that a direct lines system to solve such worst off regions should be built to have public transportation take as much time as driving an automobile by establishing lines for automobiles only, minimize time lost from hopping up and down a bus and maximize connections.