• Earthquakes and Structures
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• v.18 no.1
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• pp.97-111
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• 2020

Cylindrical steel tanks are important components of industrial facilities. Their safety becomes a crucial issue since any failure may cause catastrophic consequences. The aim of the paper is to show the results of comprehensive FEM numerical investigation focused on the response of cylindrical steel tanks under mining tremors and moderate earthquakes. The effects of different levels of liquid filling, the influence of non-uniform seismic excitation as well as the aspects of diagnosis of structural damage have been investigated. The results of the modal analysis indicate that the level of liquid filling is really essential in the structural analysis leading to considerable changes in the shapes of vibration modes with a substantial reduction in the natural frequencies when the level of liquid increases. The results of seismic and paraseismic analysis indicate that the filling the tank with liquid leads to the substantial increase in the structural response underground motions. It has also been observed that the peak structural response values under mining tremors and moderate earthquakes can be comparable to each other. Moreover, the consideration of spatial effects related to seismic wave propagation leads to a considerable decrease in the structural response under non-uniform seismic excitation. Finally, the analysis of damage diagnosis in steel tanks shows that different types of damage may induce changes in the free vibration modes and values of natural frequencies.

• Korean Institute of Interior Design Journal
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• v.18 no.6
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• pp.229-238
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• 2009

Currently, subway is becoming a major part of transportation and living environment in large cities such as Seoul or Hong Kong. As the numbers of subway lines and stations increase, visual cues indicating places are needed for users with various destinations, and environmental colors as well as line colors can be expected as effective informations for easy wayfinding. The purpose of this study is to understand the current color applications in terms of creating regional differentiation and informing subway lines in the transfer stations of Seoul and Hong Kong, by field investigation. The investigation has been proceed on 24 transfer stations from February to April, 2009 by taking photos and measuring environmental colors using Minolta spectrophotometer CM-2600d. As a result, regional differentiation in color application appeared generally low in both Seoul and Hong Kong but various 'hues' differing each station are used in Hong Kong, compared to limited use of 'hues' in Seoul, In terms of 'value', the rate of Seoul appeared lightly higher than that of Hong Kong, and the use of medium high rate of 'saturation' of main and secondary colors are shown as a remarkable character of Hong Kong.

• Advances in concrete construction
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• v.8 no.2
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• pp.119-126
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• 2019

This paper reports an experimental investigation conducted to evaluate the durability performance of concrete mixtures prepared utilizing blends of Type I Portland cement (OPC) and natural pozzolans (NPs) obtained from three different sources in Saudi Arabia. The control concrete mixture containing OPC alone as the binder and three concrete mixtures incorporating NPs were prepared keeping water/binder ratio of 0.4 (by weight), binder content of $370kg/m^3$, and fine/total aggregate ratio of 0.38 (by weight) invariant. The compressive strength and durability properties that included depth of water penetration, depth of carbonation, chloride diffusion coefficient, and resistance to reinforcement corrosion and sulfate attack were determined. Results of this study indicate that at all ages, the compressive strength of NP-admixed concrete mixtures was slightly less than that of the concrete containing OPC alone. However, the concrete mixtures containing NP exhibited lower depth of water penetration and chloride diffusion coefficient and more resistance to reinforcement corrosion and sulfate attack as compared to OPC. NP-admixed concrete showed relatively more depth of carbonation than OPC when subjected to accelerated carbonation. The results of this investigation indicates the viability of utilizing of Saudi natural pozzolans for improving the durability characteristics of concrete subjected to chloride and sulfate exposures.

• Journal of recreation and landscape
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• v.12 no.4
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• pp.17-24
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• 2018

With industrialization, environmental problems have become severe worldwide as resources are exhausted for mass production purposes and pollutants are produced in excess of nature's capacity to absorb them. Since modernity, urban parks have emerged as an important element for addressing challenges facing urban environments, which include environmental degradation. In 1987, the Brundtland Commission's report presented a sustainable developmental perspective in solving environmental problems and provided ideas for sustainable design and sustainable urban park landscape design. The purpose of this study is to analyze sustainable design applied to Houtan Park in central Shanghai, China from the perspective of social culture preservation, ecological restoration, and economic effect, and to provide the basic data for urban park design in similar areas in the future. This study consists of a literature survey and a field investigation. The field investigation lead to analysis from three perspectives: social culture preservation, ecological restoration, and economic effect. The literature survey examined sustainable urban parks and Houtan Park based on relevant papers, newspaper articles, and reports. Through actual visits (Aug. 28 - Sep. 1, 2018), it also examined the elements of sustainable design that were applied to the architecture. The three sustainable design elements derived from this study, being a sustainable design for the future, will be used as an important basis for developing urban parks for the regeneration of brownfields in many areas in China.

• Journal of Environmental Health Sciences
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• v.39 no.3
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• pp.197-210
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• 2013

Several US veterans stationed in Korea have told the press that around 250 fifty-five gallon drums of herbicides, including Agent Orange, were buried at Camp Carroll in 1978. Joint Korean-US Agent Orange investigation and environmental and health studies were started in July 2011. Korean soldiers and military personnel who served in Vietnam during 1964-1973 or near the demilitarized zone in Korea during 1967-1970 were exposed to dioxincontaminated Agent Orange. The joint Korean-US Agent Orange investigation team found that herbicides, pesticides, solvents and other chemicals -not Agent Orange- were buried at Camp Carroll. However, there remains the possibility that Agent Orange was stored and buried at Camp Carroll or other military camps in Korea. Adverse health effects have not been clearly explained despite a number of health studies among veterans in Korea with potential Agent Orange exposure. Although the Korean government has been compensating veterans and military personnel with 18 presumptive-service-connected-diseases and their offspring with three diseases, there are many veterans, military personnel and civilians who require the government°Øs support. The environmental study on contaminated sites and health studies among veterans and civilians were initiated three or four decades after possible Agent Orange contamination and exposure. Several toxic chemicals, including dioxin-contaminated Agent Orange, could remain in the environment and could have hazardous effects on the health of exposed people for more than several decades. Further environmental investigations and health studies are needed to ensure public safety and health, and government support should be guaranteed for people potentially exposed to these toxic chemicals.

• Economic and Environmental Geology
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• v.41 no.5
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• pp.475-484
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• 2008

In this study, we analyzed national mining investment security and country risk, and suggested a new index for exploration and development investment for mining projects in abroad by an analysis of relationship between these grades and mineral resource development investment. For this, potential risks for mining in mineral-rich countries are assessed, and the risk of the exploration and development investment for mining projects is relatively evaluated by OECD country risk. It is noted that countries of the lower ranks in OECD are consistently good agreement with the high grade in Behre Dolbear Group Inc. for favorable mineral exploitation, whereas the higher ranks have shown diverse and high risks for the mining investigation and development. Consequently, it is necessary that assessment of the relationship between mineral resource index and country risk for mining projects to be investigated and developed in future should be applied before business decision of mineral investigation projects in abroad.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.6
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• pp.634-639
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• 2012

The contribution levels of emissions from the heavy-duty vehicles have been continuously increased. Among the exhaust emissions, NOx (nitric oxides) have a ratio of 73.2% and particle matters have a proportion of 61.8% in the heavy-duty vehicles. Also, natural gas vehicles have the 78.9% of total registered local buses in Korea. Therefore, the investigation on emission characteristics of heavy-duty vehicles using CNG and diesel fuel according to the various driving cycles was carried out in this study. In order to analyze the emission characteristics, the five kinds of buses by using CNG and diesel fuels with a after-treatment devices (DPF, p-DPF) was used and five test driving schedules were applied for analysis of emission characteristics in a chassis dynamometer. To analyze the exhaust emission, the exhaust emission and PM analyzers were used. From this study, it is revealed that diesel buses with after-treatment had reduced emission of CO, HC, PM but NOx. Also, NMHC emission of CNG bus have a higher level and NOx level was similar with diesel buses. In addition, emissions in NIER06 with slow average speed shows lowest levels compared to other test modes.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.822-828
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• 2007

Perchlorate is an unregulated contaminant but recently many cases of perchlorate contamination have been reported in the US. In Japan, also, a couple of contamination incidents caused by perchlorate occurred. Against this backdrop, investigation on perchlorate was urgent for Korea. Accordingly, perchlorate investigation in tap water and river water was conducted one time a week for seven consecutive weeks at major water sources of Korea including Han River, Guem River, Yeong-san River, and Nak-dong River. Perchlorate was not found at Han River, Guem River, and Yeong-san River. However, all the 4 tap water samples in Nak-dong River recorded high level of perchlorate. Among others, NT1 located at Daegu posted the highest value of $22.3{\mu}g/L$. This level is lower than $24.5{\mu}g/L$, the threshold recommended by US EPA. Still, perchlorate contamination in drinking water can deal a heavy blow to nerve development of infants and children by causing iodine deficiency. At the 1st and 2nd investigations, perchlorate concentration reached $18.7{\sim}95.6{\mu}g/L$ and $4.0{\sim}25.6{\mu}g/L$ respectively, both of which are relatively higher. The high perchlorate concentration in Nak-dong River was possible because of the waste water discharged from LCD manufacturing factory which was located at NS3 in Gumi, Korea. Perchlorate concentration of waste water from the factory was $730{\sim}1,858{\mu}g/L$.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.269-281
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• 2021

Land creeping is the imperceptibly slow, steady, downward movement o f slope-forming soil or rock. Because creep-related failures occur frequently on a large scale without notice, they can be hazardous to both property and human life. Korea Forest Service has operated the prevention and response system from land creeping which has been on the rise since 2018. We categorized and proposed three survey steps (e.g., preliminary, regional, detailed) for investigation of creeping susceptibility site with a focus on geophysical mapping of a selected test site, Yongheung-dong, Pohang, Korea. The combination of geophysical (dipole-dipole electrical resistivity tomography and reciprocal seismic refraction technique, well-logging), geotechnical studies (standard penetrating test, laboratory tests), field mapping (tension cracks, uplift, fault), and comprehensive interpretation of their results provided the reliable information of the subsurface structures including the failure surface. To further investigate the subsurface structure including the sliding zone, we performed high-resolution geophysical mapping in addition to the regional survey. High-resolution seismic velocity structures are employed for stability analysis because they provided more simplified layers of weathering rock, soft rock, and hard rock. Curved slip plane of the land creeping is effectively delineated with a shape of downslope sliding and upward pushing at the apex of high resistive bedrock in high-resolution electrical resistivity model with clay-mineral contents taken into account. Proposed survey steps and comprehensive interpretation schemes of the results from geological, geophysical, and geotechnical data should be effective for data sets collected in a similar environment to land-creeping susceptibility area.

• Korean Institute of Interior Design Journal
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• no.40
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• pp.126-138
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• 2003

Since the 20th century, it has been the most important agenda that issued the environment of earth. And it has been enormous endeavors for providing the environmental-friendly. It has now outcome as a policy of estimate and acknowledgement for providing the environmental-friendly. Regarding that is the most efficient method in a practical sense, the policy has rapidly been developed. This study is an attempt to categorize interior design of the policy. Thus main-body of this study shall be clarified the definition of the notion of the environmental-friendly design and investigated the element of harm against the environmental-friendly as well. Eventually the conclusion is to provide a guideline for the environmental-friendly especially for the field of interior design materials, by the investigation of the exiting policy for the environmental-friendly design.