• Carbon letters
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• v.28
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• pp.105-110
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• 2018

Owing to their scalability, flexible operation, and long cycle life, vanadium redox flow batteries (VRFBs) have gained immense attention over the past few years. However, the VRFBs suffer from significant polarization, which decreases their cell efficiency. The activation polarization occurring during vanadium redox reactions greatly affects the overall performance of VRFBs. Therefore, it is imperative to develop electrodes with numerous catalytic sites and a long cycle life. In this study, we synthesized heteroatom-rich carbon-based freestanding papers (H-CFPs) by a facile dispersion and filtration process. The H-CFPs exhibited high specific surface area (${\sim}820m^2g^{-1}$) along with a number of redox-active heteroatoms (such as oxygen and nitrogen) and showed high catalytic activity for vanadium redox reactions. The H-CFP electrodes showed excellent electrochemical performance. They showed low anodic and cathodic peak potential separation (${\Delta}E_p$) values of ~120 mV (positive electrolyte) and ~124 mV (negative electrolyte) in cyclic voltammetry conducted at a scan rate of $5mV\;s^{-1}$. Hence, the H-CFP-based VRFBs showed significantly reduced polarization.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.2
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• pp.118-126
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• 2006

In oral and maxillofacial surgery, bone graft is very important procedure for functional and esthetic reconstruction. So, many researcher studied about bone graft material like autogenous bone, allograft bone and artificial bone materials. The purpose of this study is to evaluate the quantity of bone generation induced by $Grafton^{(R)}$ graft, human allogenic demineralized bone matrix. Total 24 sites of artificial bony defects prepared using trephin bur(diameter 8 mm) on parietal bone of six adult New Zealand White rabbits. Experimental group had six defect sites which grafted $Grafton^{(R)}$(0.1 cc). Active control group had nine defect sites, into which fresh autogenous bone harvested from own parietal bone was grafted and passive control group had nine defect sites without bone graft. After six weeks postoperatively, the rabbits were sacrificed. The defects and surrounding tissue were harvested and decalcified in 10% EDTA, 10% foamic-acid. Specimens were stained with H&E. New bone area percentage in whole defect area was measured by IMT(VT) image analysis program. Quantity of bone by $Grafton^{(R)}$ graft was smaller than that of autograft and larger than that of empty defects. In histologic view $Grafton^{(R)}$ graft site and autograft site showed similar healing progress but it was observed that newly formed bone in active control group was more mature. In empty defect, quantity and thickness of new bone formation was smaller than in $Grafton^{(R)}$-grafted defect. $Grafton^{(R)}$ is supposed to be a useful bone graft material instead of autogenous bone if proper maintenance for graft material stability and enough healing time were obtained.

• Korean Journal of Heritage: History & Science
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• v.55 no.2
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• pp.132-144
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• 2022

The representative cultural heritage showing relatively clearly the growth and development of the Mahan culture in Jeollabuk-do is the tombs in Sangun-ri, Wanju. The tombs were excavated in the early 2000s; however, little effort has since been made to investigate or preserve the wider area around the tombs. Thus, only the status quo has been maintained except for the conservation of a few relic parks. In recent years, active cultural management has become necessary to maintain the historic areas in the Mahan cultural region, so these tombs are once again receiving attention. To further the preservation efforts in the area, it is important to actively discuss budget adjustments, consider additional investigation, and re-examine the academic value of the historic site. Practical limitations mean that it is necessary to approach the conservation strategy in stages. The first step is to have the areas of cultural interest and any adjacent lands urgently designated as provincially protected cultural heritage. Consequently, historically important areas on private land should be identified and purchased. Thereafter, a preservation plan should be established to reinforce the historical value of the sites as nationally designated historic sites. This can be achieved through the restoration of the landscape adjacent to the historic sites, as well as additional investigations and designation of sites in surrounding areas. These goals can only be achieved with the active interest and support of relevant institutions.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.6
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• pp.107-115
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• 2017

This study illustrated the process of bar structure and vegetation coverage to understand historical changes of riverbed and suppose adaptive management in Tan-chun ecological landscape reserve. The study site that lower reach of the Tan-chun are known as habitats of migratory bird and aquatic species with dynamic riverbed. Aerial photos from 2006 to 2016 and surveyed vegetation data in 2006 and 2016 were used by analysis of landscape changes and comparison of vegetation coverage. Study area is classified into 3 sites (A: straight site, B: meandering site, C: meandering and junction with Yangjae-cheon). The result showed that bar area of A and C sites gradually increased, B site decreased during 10 years. Also, ratio of bar area to vegetation coverage and level of vegetation coverage increased in all sites during 10 years. All sites seem to have experienced the terrestrialization with time. On the other hand, ratio of annual vegetation increased and ratio of perennial vegetation decreased in C site in 2016 compare to 2006. Because area of Japanese Hops (Humulus japonicas) as one type of annual vegetation increased, other vegetation could not grow up by its powerful expandability. It is time to make active adaptive management based on not only continuos monitoring but also revaluation of river conditions in order to enhance habitat quality and quantity in Tan-chun ecological landscape reserve.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.648-658
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• 1995

The present study has been performed to evaluate the clinical, microbiological, biochemical and immunological parameters associated with the periodontal disease activity in adolescent periodontitis. 21 young adolescents with evidences of periodontal attachment loss participated in the study for upto 3 years of examination. Probing pocket depths and attachment levels of whole dentitions were annually recorded and 4 deepest pockets, with initial probing depth ${\geq}$ 4mm, were selected as the representative experimental sites of a patient. Sites experiencing attachment loss ${\geq}$ 1mm during the 3-year experimental period were designated as the active sites and these sites were examined for the microbiological and biochemical profiles at the time when attachment loss occurred. Microbiological assay included cultural studies and PerioScan for monitoring BANA(+) organisms(e.g. Porphyromonas gingivalis, Treponema denticola, Bacteriodes forsythus). Biochemical assay has been performed for monitoring GCF levels of neutral protease. Serum IgG and IgG2 titers against Porphyromonas gingivalis 381 were determined of a patients at the beginning and the end of the study, respectively for patient-based analysis. The results indicated that the parameters consisting of microbiological cultures and GCF neutral protease exhibited low association with the periodontal disease activity in adolescents. However, the specificity for microbiological culture of the selected periodontopathic organisms(Aa,Pg,Pi) were considerably high. Moreover, the clinical pameters such as bleeding on probing and presence of plaque as well as IgG levels against Pg at the baseline exminations were closely associated with the subsequent evidences of attachment loss during the whole experimental period(3-year).

• Journal of Information Management
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• v.40 no.2
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• pp.1-24
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• 2009

This study explored the scientific web spaces of Korea and Japan by applying webmetric and social network analysis techniques with the aim of ascertaining international scholarly communication characteristics between the two countries. In general, more links were generated from the Korean scientific web sites to the Japanese sites than those from the opposite direction, thus implying a higher usage of Japanese scientific information on the web in Korean sites. In addition, university sites in the two countries were highly linked on the web revealing the most active institutions in scholarly communication were the universities. Based on the link analysis, the study also indicated which country was more dependent on the other in scholarly communication in specific scientific fields.

• Korean Journal of Heritage: History & Science
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• v.43 no.1
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• pp.128-159
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• 2010

In this study, the progress of domestic cultural properties designation, the changes and problems in classification were examined, and the relationship among Traditional Pal-kyung, Dongcheon-gukok, and Modern Pal-kyung were investigated targeting total of 68 cases of state-designated cultural properties of scenic sites in order to show that the traditional significance and value are being inherited today. The major results of this study are as follows. First, increase in scenic site designations with historical, cultural, and scenic characteristics can be viewed as an active intent to embrace the concepts such as cultural utilities, historical characteristics, literary value, and ideological backgrounds, which were specified as the basis for designation in the early Cultural Property Protection Law. Accordingly, it is very encouraging that the concept of cultural attractions such as traditional gardens and observatory points are regarded as an important standard for designation of scenic sites. Second, as for the classification of scenic sites per type, it was found that 'places with excellent natural scenery' were 44.16%(30 cases), followed by 'famous buildings or gardens and places with important legend' occupying 30.9%(21 cases), 'places with famous scenery' occupying 13.2%(9 cases), 'places with outstanding historical cultural and scenic value' that occupying 10.3%(7 cases), and 'animal and vegetation habitat with beautiful scenery' (1 case). Third, according to the current classification standards for scenic sites, there were only 7 cases which could be classified into Pal-kyungs(Famous 8 Sceneries) and 3 cases classified into Dongcheon(beautiful scenery surrounded by mountains and rivers), but there was no Gugok(beautiful valleys). Consequently, in terms of external appearance, the scenic sites among the total scenic sites that could be classified into Palkyung and Gugok were only 14.7%(10 cases). Fourth, the traditional scenic sites based on literal references and Internet analysis occupied 67.7%(46 cases), which were found to be scenic sites related to the traditional Pal-kyung among which 38 cases(55.9% of 46 cases) were included based on the scenery and 8 cases(11.8% of 46 cases) were included due to the scenery at the time. Fifth, there were 8(11.8%) scenic sites which were related to Dongcheon, and 4 cases(5.9%) related to Gugok. Also, it was found that total of 40(48.9%) scenic sites designated as modern scenic sites were playing the role of local scenic sites, and they were used as the tourism advertising contents. Sixth, it was identified that there were 62 cases(91.2%) of scenic sites in total related to traditional and modern Pal-kyung or Dongcheon-gugok, and unlike explicit classifications, most of the designated scenic sites were found to be deeply connected with the historical and cultural significance contained in the scenaries.

• Korean Journal of Construction Engineering and Management
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• v.19 no.5
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• pp.90-100
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• 2018

Government needs a risk assessment method that is effective in preventing accidents as a part of the three principal projects of the government for protecting the people's lives for establishing preventative measures to prevent accidents in the construction sites, which accounted for more than half of all accidental mortality accidents, and promote the safety-oriented culture for making fundamental changes. Accidents at the medium and small sized construction sites accounted for 88.9% of the total construction accidents. The data indicates that improper management and lack of advanced safety measures due to the absence of a safety supervisor are the biggest problems. It is believed that active measures to evaluate and prevent risks at construction sites are necessary for preventing accidents in the medium and small sized construction sites. The objectives of this study is to identify the key risk items of common accident causes and propose a practical, preemptive, and improved risk assessment method by evaluating the problems in the safety management of construction sites for reducing the accident rate in the medium and small sized construction sites.

• Journal of Environmental Science International
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• v.14 no.5
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• pp.457-461
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• 2005

The survey of user's satisfactory degree of location, plantings, facilities, operation, and management factors on national parks' camp sites was carried out. Many problems were analyzed and identified. This survey was for proposing the correct way to plan and draft for camping site after this. In addition to, the realization of environmental education through nature friendly recreation was aimed at. According to the result of the survey, the followings were suggested as necessities to improve the camp site. 1. Repair and replacement of insufficiently managed facilities should be aimed at. 2. Facilities for a handicapped person should be preferentially introduced. 3. Active management and publicity in low-demand season that practiced by developed countries should be carried out. Seasonal program for various age groups should be operated. 4. Surrounding tourist site, camp site, and trail should be organically connected by shuttle bus and other transports. A survey was carried out for the user satisfaction in the campsites of national parks. Based on this survey concerned with the location, planting, facilities, operation and management, the problems were identified and analysed to improve future design and plan of the campsites. This study aims for the realization of environmental education through nature friendly recreation. The following points are suggested as needed according to the survey result. 1. damaged facilities should be repaired or replaced. 2. introduction of the facilities for disabled should be prioritized. 3. consistent and active management and publicity work should be operated in the off-peak season. and the seasonal activity programs for the various age groups should be provided. 4. the site should be well connected with other surrounding campsites and tourist sites using the shuttle bus and other transport method.

• Journal of Korea Soil Environment Society
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• v.1 no.1
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• pp.39-46
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• 1996

For the purpose of development of bioremediation technology for soil contaminated by chlorinated phenols, this study was focused on the isolation and characterization of bacteria capable of degrading chlorinated phenols, the establishment of analytical methods for chlorinated phenols, and the investigation of the contaminated sites. One site near the Incheon Industrial Complex was identified as a pentachlorophenol (PCP)-contaminated spot. The soil brought from the PCP-contaminated site contained 10-100$mu\textrm{g}$/g wet soil of PCP. Many bacterial strains capable of growing on a minimal medium containing PCP were isolated from 15 soil samples collected throughout the land, and among them, 10 active isolates were finally selected for the further studies on the biodegradability and for the use in in situ bioremediation of contaminated soil. These isolates showed species-specific pattern in PCP-decrease and cell growth in a minimal medium containing 500-1,000mg/ιPCP. Strain Bul degraded 90% of PCP at 216 hrs after incubation. Expecially, strain Bu34 was capable of degrading 4,000mg/ι PCP and was identified as Pseudomonas putida Bu34. It is seemed that the isolated active bacteria could be effectively used for the bioremediation of PCP-contaminated sites.