• Journal of Environmental Policy
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• v.8 no.2
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• pp.63-82
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• 2009

Because many people suffer from physical and mental damage caused by the noise created by transportation infrastructure, including road traffic, rail, and aircraft, developed countries have conducted research on predicting and solving the impact to human health from being exposed to transportation noise. Therefore, this study suggests a fundamental plan to assess the health impact of transportation noise on the basis of domestic and foreign prediction results regarding the health impact of transportation noise. The domestic and foreign exposure-response expressions, including the noise index and the health impact indicator of annoyance and sleep disturbance, are compared, and it is found that domestic individuals show a more sensitive response to transportation noise. Based on domestic and foreign research, and a case study regarding the health impact of transportation noise, a fundamental plan to assess the health impact of transportation noise comprises the preparation of objective assessment standards through the improvement of exposure-response models, and the establishment of reduction measures which can improve the quality of the transportation noise environment.

• Journal of the Korea Concrete Institute
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• v.24 no.5
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• pp.577-584
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• 2012

Carbonation resistance is one of the most influencing factors on durability of concrete. Alkali activated slag (AAS) is known to have weaker resistance for carbonation than OPC due to the low calcium contents. In this paper, the carbonation characteristic of AAS mortar which is related to the basicity (CaO/$SiO_2$) was investigated. In order to give the various basicity conditions, SM (source material) was blended with quicklime (CaO) and silicon dioxide ($SiO_2$) by adopting mechano-chemical treatment method. Experiments including flow test, compressive strength test, carbonation depth test, together with XRD, FTIR and TGA were employed to evaluate the effects of basicity of SM on the carbonation characteristics. The test results showed that the carbonation resistance effectively increased with the increase of the basicity of SM.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.366-375
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• 2016

This study aims to investigate the impact of total, native-born, and foreign-born employment rates on the increases of GDP and per capita GDP for 24 OECD countries out of 34 countries depending on data availability. The panel data analysis is formed by a fixed-effects model which allows dummy variable in it to permit the intercept term to vary over time-series and cross-sectional units. Empirical evidences obtained by simple and multiple panel regressions reveal that the contribution to increasing of GDP by foreign-born employment is obviously lower than the one by native-born employment. And, native-born labor is substituted by foreign-born labor. It also has to be mentioned that the labor is playing a key role in increasing in national income. And, therefore, labor-related policy should be concerned on decreasing in labor productivity and segmentation of labor market resulted from inflow of foreign labor. It means that labor-related policy has to take care of not only the magnitude, but also the quality of foreign-born labor.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.438-438
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• 2011

팔머가뭄지수(Palmer Drought Severity Index, PDSI)는 가뭄을 정량적으로 표현하기 위해 제안된 최초의 포괄적인 가뭄지수라 할 수 있다. 가뭄을 단순히 하나의 기상인자로만 판단하려 한 것이 아니라 수문순환 과정 속에서 여러 가지 요소들의 복합적인 작용에 의한 결과로 인식하고 이를 가뭄지수 산정 과정에 고려하고자 하였다. 따라서 PDSI는 가뭄뿐만 아니라 습윤상황을 모니터링 하기 위한 용도로 이용될 수 있으며, 수분수지 분석을 통해 얻을 수 있는 함양량, 유출량, 토양수분량의 정보는 그 자체로서도 분석 대상 지역의 수분상황과 관련된 중요한 정보라 할 수 있다. 이러한 점에서 PDSI는 방법론상의 여러 가지 한계에도 불구하고 지금까지 가뭄의 모니터링 및 관리를 위해 우리나라를 비롯한 여러 국가 및 지역에서 널리 이용되고 있으며, 가뭄 정량화를 위한 새로운 가뭄지수 개발 시 적합성의 비교 기준으로 고려되고 있다. 그러나 지금까지 우리나라에서는 PDSI에서 고려하고 있는 기상 및 수문학적 조건이 우리나라의 상황을 적절히 표현할 수 있는가에 대한 검토가 미흡한 상황이라 할 수 있다. 우리나라의 자료를 이용하여 PDSI를 산정하였다 할지라도 지수 산정 과정에서 고려하고 있는 기상 및 수문특성이 적절하지 않을 경우 산정된 PDSI가 나타내는 가뭄상황과 실제 우리나라의 가뭄상황은 다를 수 있다. 특히 PDSI 산정 과정에서 잠재증발산량 산정 방법으로 이용하고 있는 월열지수법은 방법의 한계로 인해 우리나라와 같이 동절기 평균기온이 0도 이하로 떨어지는 경우에는 증발산량이 발생하지 않는 것으로 고려하고 있다. 이는 우리나라의 실제 증발산 발생 양상과 비교할 경우 크게 차이가 나는 점이라 할 수 있으며, 강수량과 증발산량의 관계에 대한 검토로부터 지수 산정 과정이 시작되는 PDSI에 있어 이러한 오차는 결과의 신뢰성 확보에 많은 어려움을 초래할 수 있다. 따라서 본 연구에서는 기존 PDSI에서 이용하고 있는 월열지수법을 대체할 수 있는 방법에 대해 검토하였으며, 잠재증발산량 산정 방법의 변경에 따라 산정된 PDSI의 변동 양상에 대해 분석하였다. 본 연구의 결과를 통해 가뭄 모니터링 및 관리를 위한 지표로 널리 이용되고 있는 PDSI의 활용에 있어 유용한 정보 제공이 가능할 것으로 판단된다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.1
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• pp.55-63
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• 2013

In this study, seismic performance was evaluated considering the deterioration level for the low-rise and moderate buildings with non-seismic details which are most common in Korea. Evaluation results showed that the deterioration condition is relatively good even after 24 years of construction but the seismic performance did not satisfy the protection index in the first and second evaluation. In case of the third evaluation, the goal performance was satisfied based on the interstory drift ratio but reinforcement is found to be necessary. Seismic performance was evaluated after the target buildings were reinforced in the walls, bracing, and damper. Results showed the interstory drift ratio drastically reduced regardless of reinforcement methods and satisfied the level of immediate occupancy. In case of wall reinforcement, however, base shear increased more than double which requires review on the existing foundation.

• The Journal of the Korea Contents Association
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• v.15 no.6
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• pp.276-282
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• 2015

Fetal cerebellum is grow depending on the gestational age, measurement of transverse cerebellar diameter(TCD) is being used import indicator of fetal growth prediction in clinical. In this study, the subjects were normal pregnant women 20~37 week of gestation, and the volume scan was conducted on the 340 subjects. The research reports was indicated by regression curve the growth of fetal TCD in accordance with the gestational age. It got to the value of the results from a linear regression equation. Measurement fetal TCD using 3D US was statistically significant(p<0.001) and useful in the prediction of gestational age. TCD increases with gestational age can also distinguish between the normal fetal and prediction of accurate gestational age of fetal growth retardation. If the basic data of the present study, ongoing research is performed, the TCD using by 3D US are expected to be usefully applied in the correct prediction gestational age.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.2
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• pp.92-100
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• 2003

Analysis and results of the relationship between the NDVI and terrain element such as elevation, slope, aspect in Chunahn city area are as follows. It does not show the linear relationship between NDVI and analyzed terrain element such as elevation, slope, aspect, etc. and there is a trend such that the deviation of NDVI is decreased as the elevation and slope is increased. It appears that there is trends such that the distribution range of NDVI is discontinuously changed as the elevation and slope is increased. The distribution range of NDVI is discontinuously decreased based on about 50m and 100m borderline in elevation case, and slope $10{\sim}20^{\circ}$ borderline in slope case, respectively. Any special trend is discovered in the relationship between aspect and NDVI.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.2
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• pp.139-143
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• 2009

We examined the vertical distribution of specific microbial groups and the patterns of microbial community structure within the soil profile using phospholipid fatty acid (PLFA). Samples were collected from the soil surface down to 15 cm in depth from paddy and upland fields located in Daegu, Korea. The two fields have been fertilized with only chemical fertilizers N, P, K for 33 years. Principal component analysis of the PLFA signatures indicated that the composition of the soil microbial communities changed significantly with the cultivation practices and soil depth, suggesting that cultivation practices of paddy and upland fields had more significant influence on soil microbial community than the soil depth did. The soil microbial communities changed more drastically with soil depth in upland field than in paddy field, with making thicker soil surface in paddy field in terms of soil microbial community. The ratios of cyclopropyl/monoenoic precursors and total saturated/total monounsaturated fatty acids increased with soil depth, suggesting that the deeper soil horizons are more carbon-limited and anaerobic than surface soil. The community analysis using PLFAs as biomarkers revealed that Gram-positive bacteria and actinomycetes tended to increase in proportional abundance with increasing soil depth, while the abundance of Gram-negative bacteria and fungi were highest at the soil surface and substantially lower in the subsurface.

• 한국해양학회지
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• v.13 no.1
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• pp.1-8
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• 1978

A seismic reflection Survey was carried out in the offshere area between Geoje Island and Namhae Island, utilizing the echosounder with the frequency 28KHz and thd Uniboom with the filter band 800∼2000Hz. The results show the submarine topography, sedimentary layer structure and the depth distribution of the base rock. The water depth of the sea in the survey area is less than 80m; up to 40m contour line the sea bottom surface has a slight dip(about 1/1000), while in the zone deeper than 40m the bottom topography has a irregular relief. The thickness of the whole sedimentary deposit is about 20∼70m and divided into 3 layers: Upper layer(A layer) with horizontal laminae, intermediate layer(B layer) with cross-bedding and groove structure, and lower layer(C layer) not showing any sedimentary structure on the seismic reflection profile. The surface of the base rock is deeper gradually in the south-eastern part of the survey area and extends to 140m depth. The vertical sediments sequences, composed of B layer and A layer, show the type of transgressive sequences. It is interpreted that B layer was formed at one period when the sea level was lower 40∼60 than the present and ince then, following the rising of the sea level, A layer was deposited.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.2
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• pp.128-137
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• 2003

Net radiation (Rn) is one of the most fundamental components in surface energy budget. For an accurate measurement of Rn, periodic and consistent calibrations of net radiometers are required. With a 4-month time interval, two field experiments were conducted to inter-compare and calibrate two types of net radiometers (the Q-7.1 and the CNR1), widely used in flux measurements. Differences between the Q-7.1 and the CNR1 net radiometers were within 7.7%, and the errors after calibration against the standard net radiometer were ＜3.2%. Radiometric responses and calibration factors appeared to have changed with sky renditions, especially temperature difference with season's progress. We concluded that the periodically calibrated Q-7.1 can replace more expensive, more accurate CNR1 net radiometer for long-term field measurements, providing that field calibrations of net radiometers are performed every 4-6 months interval.