• Journal of the Korean Institute of Gas
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• v.22 no.6
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• pp.76-89
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• 2018

The distribution of the combined heat and power system is active as a solution to the instability of energy supply and environmental pollution caused by continuous industrial development. In Korea, the safety standards for combined heat and power system using a gas engine are insufficient therefore the study on this is needed. In this study, the safety performance and structural/material assessment items of domestic and international standards applied to the combined heat and power system were analyzed to carry out a standardization study on safety performance applicable to 20 kW gas engine combined heat and power system. In addition, the safety performance assessment (plan) of the gas engine combined heat and power system was derived by performing risk analysis and risk assessment using HAZOP. Assessment items include engine ignition systems related to safety performance, piping tight performance, watering and temperature rise performance, combustion performance, electrical efficiency, thermal efficiency, overall efficiency and humidity performance. Gas and water pipes, gas control and shut-off valves, durability, heat resistance, and cold resistance of metal or non-metallic materials related to the structure and materials of the gas engine combined heat and power systems.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.391-398
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• 2018

Mesenchymal stem cells (MSCs) are an attractive resource for refractory patients because of their anti-inflammatory/immunomodulatory capability and multi-lineage differentiation potential. The transplantation of MSCs has led to positive results in preclinical and clinical application to various diseases, including autoimmune disease, cardiovascular disease, cancer, liver cirrhosis, and ischemic stroke. On the other hand, studies have shown that paracrine factors, not direct cell replacement for damaged cells or tissue, are the main contributors in MSC-based therapy. More recently, evidence has indicated that MSC-derived exosomes play crucial roles in regulating the paracrine factors that can mediate tissue regeneration via transferring nucleic acids, proteins, and lipids to the local microenvironment and cell-to-cell communication. The use of these exosomes is likely to be beneficial for the therapeutic application of MSCs because their use can avoid harmful effects, such as tumor formation involved in cell transplantation. Therefore, therapeutic applications using MSC-derived exosomes might be safe and efficient strategies for regenerative medicine and tissue engineering. This review summarizes the recent advances and provides a comprehensive understanding of the role of MSC-derived exosomes as a therapeutic agent.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.2
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• pp.15-23
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• 2019

When the public surveying system was introduced in 1961, large scale surveying performances, such as infrastructure construction work, were dominant. However, due to changes in the environment, most of the current surveying performances focused on small scale underground facilities. The method of surveying underground facilities is as follows: "method of measurement before refilling after burying the pipeline" and "method of using exploration after refilling." There are advantages and disadvantages to each method. It became difficult to obtain the accuracy of the location of the underground facilities due to the fact that there were sections of the pipeline that had not been observed through exploration. Therefore, the 2017 performance evaluation regulations were revised. The revision included the addition of the "Underground Facilities Creation Period," a system that allows for surveys to be evaluated based on actual measurements. However, in this particular field, concerns about the advantages of exploration and the purpose of this study was to investigate the background and purpose of the limitations of the survey have been continuously raised. The purpose of this study was to investigate the background and purpose of the public surveying system and to identify the proportion of underground facilities surveying in comparison to public surveying. This study conducted surveys on the implementers of public surveying and those who did the actual surveying. The researcher has summarized the improvements that incorporate the analysis results and the field comments in the revised performance evaluation regulations in 2017.

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.759-774
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• 2018

This study was conducted to establish scores according to the importance levels of each HACCP evaluation item in cattle farm. The importance levels and score of each HACCP evaluation item was derived through the non-compliance rate and severity levels of hazard. In order to change the score criteria according to the importance of each HACCP evaluation item, we analyzed the importance of each HACCP evaluation item by using the portfolio mapping method according to the occurrence frequency and severity levels of hazard. The scores were classified into 3 point, 2 point, and 1 point, respectively, by classifying the importance of each category as 'high', 'middle' and 'lower'. Accordingly, we have established a now scoring system of each HACCP evaluation item through this study. Through the result of this study, the objectivity of the comparative evaluation was verified by implementing the currently used HACCP evaluation item to the cattle farm. In conclusion, Implementation of the result of this study to cattle farm may help to increase the objectivity and also improve more safety and hygienic cattle management and raw milk production.

• Food Science and Industry
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• v.51 no.4
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• pp.302-312
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• 2018

Bioactive peptides generated from milk proteins play an important role in the prevention and alleviation of diabetes. Whey proteins possess direct insulinotropic effect by amino acids (especially branch chain amino acids) produced through its gastrointestinal digestion. Additionally, blood glucose level can be lowered by gut hormone which called incretin [glucose dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1)]. However, physiological effects of incretin readily disappeared by dipeptidyl peptidase-4 (DPP-4) causing degradation of GLP-1. Several DPP-4 inhibitors are currently used as therapeutic medicines for the treatment of type II diabetes. More than 60 natural peptide (2-14 amino acids) DPP-4 inhibitors were identified in milk proteins. Peptide DPP-4 inhibitors act as substrate inhibitor and delay breakdown of GLP-1 both in vitro and in vivo. This review summarizes nutritional quality of milk proteins, absorption and mode of action of bioactive peptides, and finally up-to-dated knowledge on DPP-4 inhibitory peptides derived from milk proteins.

• Research in Plant Disease
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• v.25 no.3
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• pp.149-155
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• 2019

Nematode-trapping fungi develop trap and consume nematodes are an important part of the subsoil ecosystem and they share a special predator-prey relationship. Four nematode-trapping species, there with adhesive network, Arthrobotrys oligospora, A. sinensis, A. thaumasia and one with constricting ring, Drechslerella brochopaga were collected from soils in Korea and tested their predacity against 12 different nematode species. They were three feeding groups, plant-parasitic (Meloidogyne incognita and Pratylenchus penetrans), fungivorous (Aphelenchus avenae), bacteriovorous (Betlerius sp. and Diplogasteritus sp. in diplogasterid, Panagrolaimus labiatus, P. multidentatus in panagrolaimid, Mesorhabditis irregularis, Pelodera strongyloides and Rhabditis sp., in rhabditid, and Acrobeloides sp. in cephalobid). Results showed that nematode-trapping fungi successfully captured most of nematodes in Petri dish in the group of plant-parasitic nematodes and rhabditids, moderately and variably in other nematodes in 15 days. But it didn't captured A. avenae and Acrobeloides sp. both belongs to c-p group 2. Numbers of Acrobeloides sp. and A. avenae even increased during the test period. The results of this study indicated that nematode-trapping fungi may have specificity among nematode species.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.1
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• pp.66-73
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• 2019

Approximately 80% of the mines are vacated or abandoned mines and are mostly left without suitable environmental treatment facilities. In the area around the abandoned mine site, problems such as drainage of acidic city drainage and leakage of leachate occur, and ground subsidence caused by this can cause a safety accident due to sink hole occurrence. In this study, flow, compressive strength, water uptake, pore and hydration characteristics were investigated to investigate the basic properties of liner and cover material based on the replacement ratio of nano silica and silica fume in the existing blast - furnace slag fine powder. As a result, as the substitution ratio of nano silica and silica fume increased, the flow and compressive strength of nano silica specimens increased and the absorption rate decreased. In the case of pore characteristics, the amount of pores decreased as the substitution ratio of nano silica and silica fume increased. Especially, the capillary porosity of 10-1,000 nm diameter decreased. Ray diffraction analysis and SEM measurement showed that the peak positions of the hydration products were almost the same when compared with the 5% alternative test samples of Plain and silica fume.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.1
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• pp.76-84
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• 2019

This study was conducted for the purpose of examining the Outstanding Universal Value, World Heritage Values, in Suzhou classical gardens and the operational method of the protection management of historic gardens, and the results of the study are as follows; The first, as a world heritage, Suzhou gardens proved OUV by showing the taste and lifestyle of the literati, the unique class of Chinese history, to the natural environment of the East Yangtze Delta region. In addition, it showed the exchange of international culture with unique Chinese garden techniques. Second, a authentic reconstruction of garden have original value because it exist records of the near past. The 20th-century archives described by the contemporary language and describing the heritage through images using such media as photography and drawing played a decisive role in restoring gardens. Third, the protection management of Suzhou gardens, which began in the 1950s, was carried out in detail, including the reconstruction of components such as buildings, the restoration of plant materials and horticulture technique, the creation of a list through the records of trees, the maintenance of props such as plaque, furniture, and the project to improve water quality and restore waterscape. The last, after the World Heritage inscribing, Garden's protection management was proceeded in two directions. One is that through the reorganization of the administrative management system and the enactment of laws related to Suzhou classical Gardens, the listing heritage is strictly protected and managed, and the other is that the historical gardens are used to establish urban masterplan and urban identity in Suzhou. The range of garden properties greatly expanded by distinguishing the principle of conservation from protection to rational use and the grade of protection, such as whole protection, maintenance protection and protection of historical sites.

• Korean Journal of Occupational Therapy
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• v.26 no.4
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• pp.1-11
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• 2018

Objective : This study was conducted to determine the emotional labor of occupational therapists and the level of their feelings of depression and to examine the impact of their emotional labor on their depressive mood. Methods : Subjects of this study were clinical occupational therapists working at hospitals and clinics in Seoul and Gyeonggi regions. The factors of emotional labor were set as independent variables, the general characteristic variable and job characteristic variable which showed significant results in the chi-square test was set as the adjusted variable and whether the depression happens or not was set as the dependent variable, after which a multivariate logistic regression analysis was conducted. Results : Components of emotional labor, including frequency of emotional display(OR 1.699, 95% CI 1.202-2.401), attentiveness to required display rules(OR 1.436, 95% CI 1.070-1.982), and emotional dissonance(OR 1.866, 95% CI 1.336-2.607) all had a significant effect on depression. The possibility of depression was significantly higher in women than men(OR 5.736, 95% CI 1.746-18.846), those working for more than 8 hours per day than less than 8 hours per day(OR 8.609, 95% CI 2.306-32.137), and those working with children than those working with adults(OR 4.249, 95% CI 1.668-10.824). Conclusion : This study revealed that the emotional labor that occupational therapists are exposed to while interacting with patients and their caregivers exerts an influence on their feelings of depression. This suggests the need for developing various preventive intervention programs designed to alleviate the depressive symptoms of occupational therapists and formulating appropriate policies.

• Ocean and Polar Research
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• v.43 no.3
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• pp.127-140
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• 2021

At the estuaries of Bonggang and Miryong streams in the Korean southern coast, the spatiotemporal distribution and habitat environment of a nerite snail, Clithon retropictum (Gastropoda: Neritidae), which has been assigned as a legally protected species of Korea, were explored. Physicochemical environmental factors such as water temperature, salinity, tidal level distribution as well as biotic environments (chlorophyll-a concentration and epilithic microalgae composition) were monitored every month. The relationships between the environmental factors and spatiotemporal distribution of the nerite snail population were analyzed. Water temperature, salinity, and water level varied by season and lunar tidal rhythm. The spatiotemporal distribution of the nerite snail was mostly related to water salinity. Among epilithic algae which were the priority prey of snails, blue-green algae and green algae dominated in summer and autumn, while diatoms predominated during winter and spring. Chlorophyll-a concentration was highly and positively correlated with the population density of the nerite snail. The correlation coefficients were different depending on the taxon (Family) of epilithic algae. The mean population density was 302.2 inds m^-2 and 271.8 inds m^-2 in Bonggang Stream and Miryong Stream, respectively. The egg capsules of the nerite snail in the two habitats were observed from March (in Bonggang Stream) or April (in Miryong Stream) to August, and newly hatched juveniles recruited in the habitats from August were assessed with regard to frequency distributions of shell width. The occurrence of large-sized snails in upper stream reaches of both Bonggang and Miryong indicated the movement of spats from the mouth to the upper reaches during the whole life cycle.