• Safety and Health at Work
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• 제11권4호
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• pp.405-417
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• 2020

Background: Electrical socket outlets are used continuously until a failure occurs because they have no indication of manufacturing date or exchange specifications. For this reason, 659 electrical fires related to electrical socket outlets broke out in the Republic of Korea at 2018 only, an increase year on year. To reduce electrical fires from electrical socket outlets, it is necessary to perform an accelerated test and analyze the thermal, insulation resistance, and material properties of electrical socket outlets by installation years. Methods: Thermal characteristics were investigated by measured the temperature increase of electrical socket outlets classified according to year with variation of the current level. Insulation resistance characteristics was measured according to temperature for an electrical socket outlets by their years of use. Finally, to investigate the thermal and insulation resistance characteristics in relation to outlet aging, this study analyzed electrical socket outlets' conductor surface and content, insulator weight, and thermal deformation temperature. Results: Analysis showed, regarding the thermal characteristics, that electrical socket outlet temperature rose when the current value increased. Moreover, the longer the time that had elapsed since an accelerated test and installation, the higher the electrical socket outlet temperature was. With respect to the insulation resistance properties, the accelerated test (30 years) showed that insulation resistance decreased from 110 ℃. In relation to the installation year (30 years), insulation resistance decreased from 70 ℃, which is as much as 40 ℃ lower than the result found by the accelerated test. Regarding the material properties, the longer the elapsed time since installation, the rougher the surface of conductor contact point was, and cracks increased. Conclusion: The 30-year-old electrical socket outlet exceeded the allowable temperature which is 65 ℃ of the electrical contacts at 10 A, and the insulation resistance began to decrease at 70 ℃. It is necessary to manage electrical socket outlets that have been installed for a long time.

• 한국융합학회논문지
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• 제11권12호
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• pp.457-467
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• 2020

본 연구는 지속적인 자가간호가 필요한 신장이식 수술환자의 경과 기간에 따른 미충족 요구를 파악하여, 시기에 맞는 통합적인 간호중재 프로그램 개발에 필요한 기초자료를 제공하고자 시도되었다. 연구대상은 신장이식 수술 후 1년까지 입원 및 외래환자 84명으로 구성되었다. 자료수집 기간은 2020년 2월 17일부터 5월 31일까지로, Comprehensive Needs Assessment Tool in Cancer(CNAT)를 신장이식 환자에 맞게 수정·보완, 전문가 타당도 검증을 거쳐 사용하였다. 자료분석은 Chi-square, 독립 t-test, one-way ANOVA, ANCOVA, 사후검정은 Scheffé로 하였다. 연구결과 신장이식 수술 환자의 미충족 요구는 171점 만점 중 총점 평균 68.28(±38.88)점, 하부영역 8개 중 정보 및 교육이 17.92(±8.36)점으로 가장 높았다. 경과 기간에 따른 미충족 요구는 3-6개월에 비해 6개월-1년까지가 유의하게 높았다(F=7.57, p=.001). 이를 토대로 신이식 후 회복이 되어 관심이 줄어들 수 있는 6개월-1년 사이 환자의 미충족 요구는 증가하였으므로 적절한 정보와 도움을 융합하여 제공하는 간호중재 프로그램이 필요하다.

• KIEAE Journal
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• 제15권6호
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• pp.63-68
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• 2015

Purpose: Most if buildings need various repair works for preventing or delaying the deterioration which gives rise to affect the living condition or function after constructed. Therefore, a long-term repair schedule should be planned and a repair cost is required. In this paper, it aimed at providing the statistical forecast model for a repair cost in roof water-proofing work and elevator work using statistical approach with three variables such as number of household, management area and a elapsed year. Data are collected in apartment housings which are located in Seoul area and conducted with interview and questionnaire sheet. Each analyzed work is divided into a partly work and fully work. Results of this study are shown that, first, the regression model takes a multiplying type like a Cobb-Douglas function and is changed into the log-linear type to include the three variable simultaneously. Second, the goodness-of-fit of the repair cost forecasting model has a good statistics in determinant's coefficient and Dubin-Watson value. Third, the management area is stronger factor than other the number of household and an elapsed year in roof water-proofing work and elevator work.

• 한국환경복원기술학회지
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• 제8권4호
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• pp.32-42
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• 2005

To investigate the plants invasion process and dominant species in large-scale cutting slopes, slopes elapsed one year to thirteen years after construction had been selected in five counties. The obtained results are summarized as follows : The species of high appearance frequency were Alnus firma, Arundinella hirta, Miscanthus sinensi var. purpurascens, Erigeron cancdensis, Artemisia princeps var. orientalis, Oenothera odorata, Lactuca raddeana, Lactrca indica var. laciniata, Lespedeza bicolor, Youngia sonchifolia, Populus albaglandulosa, and so on. The biological type of identified vascular plants was $Ch-D_1-R_{5-e}$. In time, plant coverage was increased gradually and average of plant coverage was 1.17% in slopes which elapsed one year, 42.44% after six years, 56.67% after eight years, and 69.17% after ten years. The dominant species in the surveyed slopes were covered with Alnus firma, Artemisia princeps var. orientalis, Erigeron cancdensis, Miscanthus sinensi var. purpurascens, Arundinella hirta, Lactuca raddeana, Oenothera odorata, Boehmeria spicata, Kummerowia striata and Artemisia montana of the 59 species. The conditions of location in large-scale cutting slopes are hard to fix and germinate of seeds, and extend plant roots in the slope soil. Hence, the highly appearance species and dominance species of the area will make plant coverage quick and slope stable.

• 전기학회논문지P
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• 제58권2호
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• pp.172-177
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• 2009

Most of the causes of the failures of power transformers in operations are mechanical defects due to vibration. To identify these causes, the vibration phenomenon was measured from the power transformers in operation in the substations under the Daejeon power transmission district office of KEPCO. The measurement was performed in a 6${times}$4 structure on one side of the transformer. The vibration of the measured points was presented in 2D and 3D, and analyzed. The results according to the period in use of the transformer and the load applied to the transformer were analyzed. These results will be used as basic data to establish the vibration standard for the power transformer, In addition, with a load capability and vibration phenomenon correlation and regression analysis to identify by way of function was reached. And the vibration phenomenon pass a years with changes and to analyze correlation, was estimated to bring in the function. And then through the analysis of power transformers to set standards based on vibration data was used to.

• 보험의학회지
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• 제2권1호
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• pp.116-121
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• 1985

We've reviewed 518 cases of claims by death that had occured for one year from April, 1983 to March, 1984. As a result, we came to following conclusions; First, the greater part of the death were due to Accidental death(19.1%), Heart disease(18.9%), Malignant neoplasm(17.4%), Liver cirrhosis(10.6%), and the Cerebrovascular disease(9.7%), which were occupied by 75.7% of the whole. Second, classifying them by medical examinations or non medical, death in case of non medical examination showed 89% of the whole. And for age, section ranging from 41 to 50, from 51 to 60 and from 31 to 40 took the overwhelming portion by 27.4%, 26.6%, and 17.4% respectively, those of which showed 71.4% of the whole. Third, for the period elapsed, death within 1 year from the entrance showed 31% and that from 1 year to under 2 years 20.5%. Thus the rate of early death under 2 years stood for 51.5% of the whole.

• 보험의학회지
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• 제4권1호
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• pp.86-92
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• 1987

We've reviewed 704 cases of claims by death that had occured for one year from April, 1985 to March, 1986. As a result, we came to following conclusions; First, the greater part of the death were due to Accidental death(25.0%), Malignant neoplasm(21.2%), Heart disease(12.9%), Liver cirrhosis(9.1%), and the cerebrovascular disease(5.5%), which were occupied by 73.7% of the whole. Second, classifying them by medical examinations or non medical, death in case of non medical examinations showed 94.3% of whole. And for age, section ranging from 40 to 49, from 50 to 59, and from 60 to 69 took the overwhelming portion by 28.6%, 24.2%, and 16.6% respectively, those of wich showed 69.4% of the whole. Third, for the period elapsed, death within 1 year from the entrance showed 16.9% and that from 1 year to under 2 years 18.8%, Thus the rate of early death under 2 years stood for 35.7% of the whole.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.701-703
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• 1996

Maintenance scheduling plays an important role in evaluating the supply reliability of power systems. Since generating units must be maintained and inspected, the generation planner must schedule planned outages during the year. Several factors entering into this scheduling analysis include: seasonal load-demand profile, amount of maintenance to bo done on all generating units, size of the units, elapsed time from last maintenance, and availability of maintenance crews. This paper proposes a new algorithm to decide the multi-year maintenance scheduling with considering the total cost. We adjust the maintenance scheduling to levelize the reliability over all period. The proposed algorithm is applied to a real size power system and the developed reliability results are obtained.

• 한국환경복원기술학회지
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• 제7권6호
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• pp.84-93
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• 2004

This study was carried out to select proper species for early stage replantation in granite forest roads cut-slope. From two to sixteen year elapsed forest roads in four regional areas of Gangwon-do, sample plots were selected, and their vegetations and environmental factors were investigated. Soil organic matter, total nitrogen, soil moisture content, and bulk density in the decomposed granite soils were below 1.32%, 0.08%, 10.0%, and above 1.24g/$cm^3$, respectively. The result indicated that the soil was not good for plant growth. The environmental factors affecting distribution of species in the granite forest roads were the elapsed year, cut-slope, elevation, and cut-slope aspect. Species with high frequency in the granite forest road cut-slope ordered Lespedeza bicolor, Rubus crataegifolius, Pinus densiflora, Lysimachia clethroides, Amorpha fruticosa, Dactylis glomerata, Lespedeza cyrtobotrya, Festuca arundinacea, Spodiopogon sibiricus, Artemisia stolonifera, and Weigela subsessilis. Herbs seeded in earth stage such as Dactylis glomerata, Lolium perenne, and Festuca arundinacea had changed into perennial herbs such as Carex lanceolata, Poa sphondylodes, Patrinia villosa, Artemisia princeps var. orientalis, Spodiopogon sibiricus, Melica onoei, Artemisia keiskeana, Artemisia stolonifera, Astilbe chinensis var. davidii, Spodiopogon sibiricus, and those had changed into shrubs such as Rubus crataegifolius and Weigela subsessilis, and those had changed into trees such as Salix hulteni, Salix koreensis, and Fraxinus rhyncholhylla according to elapsed year of forest roads. Legumes such as Lespedeza sp., Pueraria thunbergiana, Amorpha fruticosa, etc., herbs such as Artemisia keiskeana, Artemisia princeps var. orientalis, Artemisia stolonifera, Astilbe chinensis var. davidii, Spodiopogon sibiricus, Miscanthus sinensis, etc., and woody plants such as Pinus densiflora, Rubus crataegifolius, Weigela subsessilis, Zanthoxylum schinifolium, Rhododendron mucronulatum, etc., with foreign herbs were considered as proper species for replantation in granite forest road cut-slope.

• 한국환경복원기술학회지
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• 제7권1호
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• pp.59-67
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• 2004

This study was carried out to select proper species for early stage replantation in granite forest roads cut-slope. From one to fourteen year elapsed forest roads in eight regional areas of Gyeongsang-do and Jeolla-do, sample plots were selected, and their vegetations and environmental factors were investigated. Soil organic matter, total nitrogen, soil moisture content, and bulk density in the granite weathering soils were below 0.4%, 0.03%, 12.4%, and above 1.2g/$cm^3$, respectively. The result indicated that the soil was not good for plant growth. The environmental factors affecting distribution of species in the granite forest roads were the elapsed year, elevation, and cut-slope aspect. Invaded species with high frequency in the forest road cut-slope ordered Pinus densiflora, Lespedeza bicolor, Rubus crataegifolius, Alnus hirsuta, Youngia denticulata, Patrinia villosa, Artemisia princeps var. orientalis, Zanthoxylum schinifolium, and Dactylis glomerata. Herbs seeded in earth stage such as Dactylis glomerata, Eragrostis curvula, Festuca arundinacea, Lespedeza sp., and Amorpha fruticosa had changed into perennial herbs and shrubs such as Youngia denticulata, Patrinia villosa, Aster scaber, Patrinia scabiosaefolia, Melica onoei, Astilbe chinensis var. davidii, Chrysanthemum zawadskii var. latilobum, Pueraria thunbergiana, Stephanandra incisa, and Clematis apiifolia, and had changed into plants such as Artemisia princeps var. orientalis, Artemisia keiskeana, Miscanthus sinensis, Pinus densiflora, Rhododendron mucronulatum, Rubus crataegifolius, and Zanthoxylum schinifolium according to elapsed year of forest roads. Leguma such as Lespedeza sp., Pueraria thunbergiana, Amorpha fruticosa, etc., herbs such as Artemisia keiskeana, Artemisia princeps var. orientalis, Chrysanthemum zawadskii var. latilobum, Miscanthus sinensis, etc., and woody plants such as Pinus densiflora, Rubus crataegifolius, Rhododendron mucronulatum, etc., with foreign herbs were considered as proper species for replantation in granite forest road cut-slope.