• Polymer(Korea)
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• v.35 no.1
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• pp.30-34
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• 2011

In this study, the effects of the electron beam irradiation on the thermal behavior and the abrasion properties of the glass fiber reinforced nylon 12 was investigated. The electron beam irradiation was carried out over a range of irradiation dose from 100 to 600 kGy with additive crosslinking agents such as triallyl cyanurate (TAC), triallyl isocyanurate (TAIC) and trimethylolpropane trimethacrylate (TMPTMA) for enhancing the crosslinking effects. The gel contents were increased dramatically above 200 kGy. It was verified that the degree of crosslinking depends on the radiation dose. The decreases of the melting temperature and the area of endothermic peak were observed as increasing the absorbed dose in the results of DSC analysis. The enhanced thermal stability was confirmed by the increases of decomposition temperature by electron beam irradiation. Furthermore, the negative deviations of the abrasion loss and the abrasion coefficients confirmed the improvement of the abrasion properties of irradiated nylon 12, as evidenced by SEM observation on the abrasion surfaces. The addition of the crosslinking agents to nylon 12 during effectively improved the thermal behavior and the abrasion properties of nylon 12 by the electron beam irradiation.

• Journal of Digital Convergence
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• v.14 no.8
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• pp.319-329
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• 2016

This study aimed to identify nurses' participation motivation, its influence factors, and their job training need. A survey was conducted on 345 nurses of general hospitals in Gyeonggi-do. Data was collected from October 5th to 18th, 2016 and was analyzed through t-test, ANOVA, Bonferroni post-test, and multiple regressions using SPSS 21.0. Participation motivation was high in 'expertise capability improvement and development' and low in personal gain and job stability. Job training need was the highest in nosocomial infection management and CPR and was the lowest in hospice and rehabilitation nursing. Participation motivation had significant differences depending on age, marital status, educational level, and clinical experience, and was influenced by the job training need of professional nursing and medical knowledge for disease treatment. Therefore, it is necessary to plan medical educational programs to enhance job training effectiveness, establish a strategy to increase participation motivation; and expand various job training support.

• Korean Journal of Cleft Lip And Palate
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• v.8 no.2
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• pp.63-70
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• 2005

Patients with cleft lip and palate usually show up maxillary hypoplasia. In these cases, a large amount of maxillary advancement is often needed to correct the severe deformity, but local soft-tissue scars around the maxilla restrict maxillary advancement and increase the relapse rate. Maxillary distraction osteogenesis is an effective method for facial and occlusal improvement in these patients. By gradually lengthening both the bones and the soft tissues, distracted midface can greatly increase postoperative stability and decrease the relapse rate. However, the maxillary extraoral appliances of the early days used were esthetically unappealing as well as difficult for the patient to manage. Recently, more inconspicuous intraoral distraction appliances have been developed and used with success. We acquired favorable result in two patients(bilateral 1 patient and unilateral 1 patient) with severe maxillary hypoplasia secondary to complete cleft lip and palate were treated with midface distraction using internal distractor (Zurich Pediatric Maxillary Distractor, KLS Martin, Tuttlingen, Germany). So, we report our experience with literatures.

• Food Science and Preservation
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• v.15 no.4
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• pp.606-611
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• 2008

Myungran Jeotkal, Korean fermented seafood, and its ingredients(hot red pepper powder, ginger, garlic, and seasoning mix) were irradiated with 0, 0.5, 1.0, 2.0, and 5.0 kGy of gamma rays and stored at 4C for 4 weeks to determine changes in microbiological and sensory characteristics. Water activities of Myungran Jeotkal, hot red pepper powder, ginger, garlic, and seasoning mix were 0.89 0.56, 0.98, 0.99, and 0.07, respectively. Myungran Jeotkal was observed to be initially contaminated. Total aerobic bacteria, yeast and mold, and coliform levels were 6.7, 4.3, and 3.6 log CFU/g, respectively. Irradiation at 2 kGy afforded approximately a 4 log reduction in total aerobic bacteria, and a 3 log drop in both yeast and mold levels and coliform bacteria(P<0.05). No viable microbial cells were detected in Myungran Jeotkal after 5 kGy of irradiation(at a detection limit of 101 CFU/g). The total aerobic bacterial level in red pepper powder was 6.3 log CFU/g and this component, of the tested ingredients, contributed most to the microbial contamination of Myungran Jeotkal. The initial count of total aerobic bacteria, 6.3 log CFU/g, was significantly reduced to 4.5 log CFU/g after irradiation(P<0.05). Sensory evaluation showed that gamma irradiation of up to 5.0 kGy did not adversely affect overall acceptability of Myungran Jeotkal or its ingredients during cold storage. Therefore, gamma irradiationwas effective to extend the shelf-life of Myungran Jeotkal.

• Journal of Wetlands Research
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• v.16 no.2
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• pp.213-220
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• 2014

Recently, river maintenance is change due to concern for the environment increases. Thus, the river restoration and river environment is best part of river maintenance. In case of Korea, existing river is improvement straightly for flood control and transportation. When the stream channel is straightly, maintain stability is important. Thus, construction of levees along the river. The various river structures for the purpose of flood control and transportation are inhibit factors of longitudinal and lateral connectivity. Connectivity is defined as the maintenance of lateral, longitudinal, and vertical pathways for biological, hydrological, and physical processes. Long-term point of view, increased connectivity is very important for a healthy ecosystem composition. As the first step of river restoration, this study described theory and concept of river continuum and the numerical model was applied to a real topography to simulate the flow analysis with or without segregated and blocked space in the Mankyung river. The results of this study can be utilized to develop the watershed connectivity assessments methods in order to the river restoration.

• Journal of Cadastre & Land InformatiX
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• v.45 no.1
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• pp.75-97
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• 2015

Recently public institutions' debt is growing therefore it became an important issue to the level that the government concerns about the possibility of financial burden to reduce the debt. Especially debt of public enterprises in metropolitan areas was in a serious state where debt in late 2013 was 43.2 trillion, which takes approx. 58.4% of 73.9 trillion of debt of all local public enterprises. Sound financial state of local public enterprises is important to public enterprises in metropolitan areas and it may affect seriously financial stability of local governments when public enterprises have financial problems. However, land supply business to form local industrial complexes or local demand for development of public rental housing business always exist; and vitalizing local economy and creating jobs through these businesses are very necessary to develop the areas. However, for local economic development, industirial land business and public rental housing business are needed. In this study, Gwangju Metropolitan City Corporation Ltd is used as a case study to evaluate the local public financial soundness via debt management assessment i.e.(using) the feasibility analysis in the urban development and housing development. As an improvement measure following the result of analysis, for the enhancement of financial soundness of urban innovation corporation, the government and local government shall evaluate and differentiate market demand, price competitiveness, and infrastructure of new town land development project to improve accuracy of project feasibility analysis. Another important insight is that there should be local government-centered management of liabilities of the local government and local public enterprises with the integrated liability management system to reduce the liability of the corporation and solve the issue of debts for local government. This study is significant in that it has analyzed cases from the theoretical aspect to secure financial soundness of national and local public enterprises.

• The Journal of the Korea Contents Association
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• v.20 no.1
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• pp.470-484
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• 2020

An earthquake of magnitude 5.4 occurred on November 15, 2017 in Pohang, which caused the damage to buildings and facilities. The earthquake displaced more than 1,700 people. After the Pohang Earthquake, immediate emergency, such as the damage survey and running of shelters have been executed appropriately. However there have been issues with subsequent restoration measures, such as the provision of temporary housing and delivery of natural disaster allowance. As there was inadequate government advertisement about the natural disaster allowance, victims of the earthquake could not receive tangible help. In Japan on the other hand where earthquakes are frequent, post-earthquake restoration protocols are planned well in advance. For example, Japanese earthquake victims are provided with a guidebook outlining different types of government aids available for them so that they can rapidly access government aid. In this study, we refer to the case of Pohang earthquake to analyse the problems in the national earthquake restoration plans and propose how they can be improved by comparing it to Japanese post-earthquake case and a Korean equivalent should be developed, to aid Korean earthquake victims to return to their every life as soon as possible.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.118-128
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• 2016

As the interest on the air-pollution is gradually rising up at home and abroad, automotive and fuel researchers have been working on the exhaust emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative after-treatment systems, using clean (eco-friendly alternative) fuels and fuel quality improvement. This research has brought forward two main issues : exhaust emission and PM (particulate matter) particle emissions of gasoline vehicle. Exhaust emission and PM particle of automotive had many problem that cause of ambient pollution, health effects. In addition, researcher studied the environment problems of the MTBE contained in the fuel as oxygenate additives. The researchers have many data about the health effects of ingestion of MTBE. However, the data support the conclusion that MTBE is a potential human carcinogen at high doses. Based on the oxygenated fuel additive types (MTBE, Bio-ETBE, Bio-ethanol, Bio-butanol), this paper discussed the influence of oxygen contents on gasoline fuel properties and evaporative emission characteristics. Also, this paper assessed the acceleration and power performance of gasoline vehicle for the fuel property.

• Journal of the Korean Applied Science and Technology
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• v.31 no.1
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• pp.113-119
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• 2014

The compositions of saturated and unsaturated fatty acids in biodiesel feedstocks are important factors for biodiesel properties including low-temperature fluidity and oxidative stability. This study was conducted to improve low-temperature fluidity of biodiesel by reducing total saturated FAME (fatty acid methyl ester) in animal fat biodiesel fuels via urea-based fractionation and by mixing plant biodiesel fuels (rapeseed-FAME, waste cooking oil-FAME, soybean-FAME, and camellia-FAME) with enriched-polyunsaturated FAME derived from animal fat biodiesel. Our results showed that the reduction of total saturated FAME in animal fat biodiesel lowered CFPP (Cold Filter Plugging Point) to $-15^{\circ}C$. Mixing plant biodiesel fuels with the enriched-polyunsaturated FAME derived from animal fat biodiesel lowered CFPP of blended biodiesel fuels to $-10{\sim}-18^{\circ}C$.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.4
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• pp.55-63
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• 2020

This study investigates the mechanical properties and reaction products of activated slag pastes depending on gypsum presence and calcium carbonate addition in terms of compressive strength tests and synchrotron X-ray diffraction. The chemicals of CaO and NaOH are used as activators with different two dosages. The reaction of CaO-activated slag without gypsum just accelerated by addition of calcium carbonate at early ages, but no improvement was observed at later ages. On the other hand, the mechanical properties of CaO-activated slag pastes with gypsum were improved with calcium carbonate, enhancing the stability of ettringite. The variation of mechanical properties of NaOH-activated slag pastes was negligible depending on calcium carbonate addition in case of no gypsum. The addition of calcium carbonate into NaOH-activated slag pastes with gypsum deteriorated its mechanical properties due to the ion competition between CO₃^2- ions and SO₃^2- ions, decreasing crystallinity of reaction products.