• Composites Research
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• v.36 no.6
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• pp.402-407
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• 2023

Activated carbon fibers (ACFs) are fibrous form of activated carbon (AC) with higher mechanical strength and flexibility, which make them suitable for building modules for applications including directional gas flow such as air and gas purification. Similarly, ACFs are anticipated to excel in the efficient capture of CO₂. However, due to the difficulties in fabricating monofilament carbon fibers at a laboratory scale, most of the studies regarding ACFs for CO₂ capture have relied on electrospun carbon fibers. In this study, we fabricated monofilament carbon fibers from PAN-based monofilament precursors by stabilization and carbonization. Then, ACFs were successfully prepared by chemical activation using KOH. Different weight ratios ranging from 1:1 to 1:4 were employed in the fabrication of ACFs, and the samples were designated as ACF-1 to ACF-4, respectively. As a function of KOH ratio, increase in surface area could be observed. However, the CO₂ adsorption trend did not follow the surface area trend, and the ACF-3 with second largest surface area exhibited the highest CO₂ adsorption capacity. To understand the phenomena, nitrogen content and ultramicropore distribution, which are important factors determining CO₂ adsorption capacity, were considered. As a result, while nitrogen content could not explain the phenomena, ultramicropore distribution could provide a reasoning that the excessive etching led ACF-4 to develop micropore structure with a broader distribution, resulting in high surface area yet deteriorated CO₂ adsorption.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.3
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• pp.25-34
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• 2020

This study examined the definition and major values, the designated procedures and types, and the designation trend in Korean scenic sites and national parks in the United States. Based on this, the analysis of the characteristics of the designation of the two natural heritages. The results are as follows; First, Scenic Sites has characteristics of complex heritage that includes academic, historical, and humanities values on the basis of landscape. As a natural heritage based on public nature, the U.S. National Park aims to contribute to the people's natural heritage and satisfy both ecological and historical values through the protection of the landscape. Second, the designation of a scenic sites are decided through deliberation by the Cultural Heritage Committee after the request of the owner, manager, or local government or by the authority of the head of the Cultural Heritage Administration. The designated survey is divided into basic resource surveys and resource surveys by type. Since the initial designation of the Sogeumgang Mountain in Cheonghakdong, Myeongju in 1970, the number of designated scenic sites was low until the 2000s, but the number of designated scenic sites has increased rapidly since 2006 due to the policy to promote the scenic site, and the proportion of natural and historical and cultural scenic sites has been balanced. The designation of the U.S. national park is decided by the Congress or the president, and the National Park Service makes a series of decisions on whether to conduct a special resource study of provisional resources through a preliminary inspection survey, whether to satisfy the criteria for designation of national parks based on the results of special resource research, and to prioritize them. The U.S. National Parks have been expanded not only by Congress but also by the president's empowerment to designate them as national monuments. With the integrated operation of the National Park Service, the number of designated cases increased as the national park included the heritage sites under the control of various ministries. In addition, a number of historical areas were designated by the enactment of the Historical Site Act, and recreational areas were designated to provide leisure space and classified and managed in a total of 18 units. Third, the comparison of the designation characteristics of the two heritage properties confirmed that the designation of natural heritage with complex value, the classification of types according to complementary designation system and resource characteristics, the establishment of the competent ministry and the balancing of the heritage according to the designation policy. The two heritages had the characteristics of complex natural heritages that met ecological, historical and academic values at the same time based on landscape and public nature. In addition, both countries have identified a system for deliberating the designation of heritage through a basic resource survey and an in-depth designation survey, and classified each type according to the characteristics of the resource. In addition, the policies for promoting scenic sites in Korea and the integrated operation of the National Park Service in the U.S. influenced the designated aspects of the two heritage sites, balancing natural heritage with historical and cultural heritage. Fourth, the resource types and conservation management methods of Scenic site and National Park were largely related. The natural areas of the U.S. National Park include types of natural monuments in Korea as major resources, and have characteristics similar to natural scenic sites. In addition, historical resources were similar to the criteria for designation of historical and cultural scenic sites in terms of landscape, and the aspects of war and celebrity-related relics were related to the types of historic sites. In terms of conservation management, the natural area of the U.S. national park has a way of keeping the original ecosystem intact, but the Korean natural heritage protection system is likely to be useful for focusing on the resource of viscosity. Meanwhile, historical resources include historical sites and historical and cultural scenic sites in the traditional era, but historical relics in the U.S. National Parks have set a time limit to modern times for war history and celebrity-related relics, and the active provision of entertainment programs based on existing resources was derived as a difference.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.210-212
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• 2004

This study was conducted to determine the fluoride intakes in 120 preschool children aged $3{\sim}6$ residing in Jumunjin(community water fluoridation area) and Kangnung(non-fluoridation area). The parents duplicated all the diets that their children ingested in a day. The acid-diffusible fluoride in the diet was isolated by the acid-diffusion technique and measured with a fluoride electrode. The mean daily fluoride intakes form all kinds of diet by children residing in Jumunjin and Kangnung were $0.445{\pm}0.354mg/day$ and $0.131{\pm}0.097mg/day$, respectively. It is concluded from this investigtion that the amount of fluoride intake of children living in Jumunjin(fluoridated areas) did not exceed the upper intake level designated by the Institute of medicine of the US National Academy of Science to avoid the risk of dental fluorosis(2.2mg/day in 4- to 8-year-olds).

• Journal of Ecology and Environment
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• v.32 no.3
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• pp.207-215
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• 2009

Greenbelts were designated by the Korean government in 1971 in 14 large cities to prevent uncontrolled urban expansion. Recently, deregulation of the greenbelt system has resulted in further development, but the ecological role of greenbelts has not been fully considered when decisions about urban management are being made. We examined the ecological roles of the greenbelt system in the Seoul metropolitan area and prepared sustainable management and improvement plans based on our analysis of landscape characteristics using satellite images covering a ${\sim}30$-year period. The loss of forest cover during this period in the greenbelt areas was lower than that in the areas outside and inside of the greenbelt. Fragmentation of forest cover was correlated with the pattern of loss of forest cover. The NDVI of the greenbelt remained steady at 90% of that in outside of the GB for three decades. This suggests that the greenbelt system has performed its primary roles well. However, the remaining green space was not adequate to provide a sink for air pollutants even when the greenbelt area was included. We discuss how the negative effects of urbanization can be reduced through sustainable management and restoration to promote ecological functioning in greenbelts and urban landscapes.

• Journal of Environmental Science International
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• v.17 no.5
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• pp.525-535
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• 2008

5 public complaint areas against odor in Changwon Industrial Complex were selected and investigated to clear up the cause of the complaint. 16 companies operated in public complaint areas were visited and had a grip of their situation about odor generation and treatment. Two samples at it's site boundary of each company were taken to measure complex odor unit. Complex odor unit at the site boundary of investigated companies in the public complaint areas, for the most part, exceeded standard(odor unit 20) in industrial area. It was due to that this area was not designated as odor control region and that there are also many problems in current laws of Odor Protection Act, Air Quality Act and regional legislation. Accordingly, It will be necessary to revise the related legislation, to organize governance, to financially support the improvement of environmental facilities and to enforce guidance and the regulation rigidly for the odor emission reduction in Changwon Industrial Complex.

• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.1-14
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• 1999

To find characteristics and areas of greater risk of oil spill at the coastal waters in Korea, some of risk factors were analyzed with historical data of oil spill and marine traffic. As a result, it is characterized that frequency of oil spill is increasing year by year and greatest percentage of spill source is fishing boat. It is proposed that the ports of Ulsan, Yeosu, Incheon and Pusan will be designated as primary area of risk as they have a higher risk of oil spills and its response authority is required to maintain appropriate regional response capability for prompt and effective response to a future spill incident. In addition, the regional response equipments at Ulsan are examined under a assumption of a medium size spill and it is found that the use of chemical dispersant can be an alternative when mechanical containment and recovery is not feasible in this area, and the existing response equipments may be appropriate to address that size of spill. However, the response authority is required to maintain more numbers of stronger boom for unsheltered waters and more quantity of concentrate dispersant to disperse all spilled oils on the water, furthermore the response authority should be prepared for a possible future catastrophic spill with sufficient equipments.

• Journal of Computing Science and Engineering
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• v.5 no.3
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• pp.161-166
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• 2011

We present a fast algorithm for Korean text extraction and segmentation from subway signboards using smart phone sensors in order to minimize computational time and memory usage. The algorithm can be used as preprocessing steps for optical character recognition (OCR): binarization, text location, and segmentation. An image of a signboard captured by smart phone camera while holding smart phone by an arbitrary angle is rotated by the detected angle, as if the image was taken by holding a smart phone horizontally. Binarization is only performed once on the subset of connected components instead of the whole image area, resulting in a large reduction in computational time. Text location is guided by user's marker-line placed over the region of interest in binarized image via smart phone touch screen. Then, text segmentation utilizes the data of connected components received in the binarization step, and cuts the string into individual images for designated characters. The resulting data could be used as OCR input, hence solving the most difficult part of OCR on text area included in natural scene images. The experimental results showed that the binarization algorithm of our method is 3.5 and 3.7 times faster than Niblack and Sauvola adaptive-thresholding algorithms, respectively. In addition, our method achieved better quality than other methods.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1257-1260
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• 2007

A single-wall carbon nanotube (SWNT) transparent conductive film (TCF) was fabricated using a simple inkjet printing method. The TCF could be selectively patterned by controlling the dot size to diameters as small as $34\;{\mu}m$. In this repeatable and scalable process, we achieved 71% film transmittance and a resistance of 900 ohm/sq sheet with an excellent uniformity, about ${\pm}\;5%$ deviation overall. Inkjet printing of SWNT is substrate friendly and the TCF is printed on a flexible substrate. This method of fabrication using direct printing permits mass production of TCF in a large area process, reducing processing steps and yielding low-cost TCF fabrications on a designated area using simple printing.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.45.2-45.2
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• 2011

Metal organic frameworks (MOF) have generated considerable interests as a potential candidate for hydrogen storage owing to their extremely high surface-to-volume ratio and low density. In this study, Pt nanoparticles of about 3 nm in size were introduced outside MOF-5 [$Zn_4O$(1,4-benzenedicarbocylate)3], which was then encapsulated with hydrophobic microporous carbon black (denoted CB@Pt/MOF-5) in order to enhance hydrogen uptake capacity without decreasing the specific surface area and hydrostability. To study the chemical composition, morphology, crystal information, and properties of the synthesized material, a variety of techniques is employed, including WXRD, XPS, ICP-AES, FE-SEM, HR-TEM, and N2 adsorption-desorption, confirming the formation of novel hybrid composite designated CB@Pt/MOF-5 with highly crystalline structure, large specific surface area and pore volume. In addition, $H_2$ storage capacity for resulting material was measured using magnetic suspension microbalance at 77 and 298 K under high-pressure condition, and the hydrostability was also tested by exposing the sample to 33% relative humidity at $23^{\circ}C$ and measuring XRD as a function of time.

• Animal Systematics, Evolution and Diversity
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• no.spc9
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• pp.80-83
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• 2016

In order to analyze a status of animal in an area where has been became a land cause of Jindo Grand Bridge established on Jindo island area, mammal status in the biggest mountain in Jindo province, Mt. Cheomchalsan has been investigated for four times from May to October of 2016. According to the investigation, 5 orders, 9 families and 15 species of inhabitation was confirmed, and water deer (Hydropotes inermis), raccoon (Nyctereutes procyonoides), cat (Felis catus), and etcetera were dominant. Biodiversity and evenness index were likely to be high as 2.24 and 0.83, respectively and it is considered that favorable condition of natural ecosystem for inhabitation of mammalian is established. Meanwhile, since the cat designated as control species is confirmed as a dominant species, it is supposed that continuous management is necessary.