• KEPCO Journal on Electric Power and Energy
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• 제2권2호
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• pp.227-232
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• 2016

To test the effectiveness of using an energy storage system for frequency regulation, the Energy New Business Laboratory at KEPCO Research Institute installed a 4 MW energy storage system (ESS) demonstration facility at the Jocheon Substation on Jeju Island. And after the successful completion of demonstration operations, a total of 52 MW ESS for frequency regulation was installed in Seo-Anseong (28 MW, governor-free control) and in Shin-Yongin (24 MW, automatic generation control). The control system used in these two sites was based on the control system developed for the 4 MW ESS demonstration facility. KEPCO recently finished the construction of 184 MW ESS for frequency regulation in 8 locations, (e.g. Shin-Gimjae substation, Shin-Gaeryong substation, etc.) and they are currently being tested for automatic operation. KEPCO plans to construct additional ESS facilities (up to a total of about 500 MW for frequency regulation by 2017), thus, various operational tests would first have to be conducted. The high-speed characteristic of ESS can negatively impact the power system in case the 500 MW ESS is not properly operated. At this stage we need to verify how effectively the 500 MW ESS can regulate frequency. In this paper, the effect of using ESS for frequency regulation on the power system of Korea was studied. Simulations were conducted to determine the effect of using a 524 MW ESS for frequency regulation. Models of the power grid and the ESS were developed to verify the performance of the operation system and its control system. When a high capacity power plant is tripped, a 24 MW ESS supplies power automatically and 4 units of 125MW ESS supply power manually. This study only focuses on transient state analysis. It was verified that 500 MW ESS can regulate system frequency faster and more effectively than conventional power plants. Also, it was verified that time-delayed high speed operations of multiple ESS facilities do not negatively impact power system operations. It is recommended that further testing be conducted for a fleet of multiple ESSs with different capacities distributed over multiple substations (e.g. 16, 24, 28, and 48 MW ESS distributed across 20 substations) because each ESS measures frequency individually. The operation of one ESS facility will differ from the other ESSs within the fleet, and may negatively impact the performance of the others. The following are also recommended: (a) studies wherein all ESSs should be operated in automatic mode; (b) studies on the improvement of individual ESS control; and (c) studies on the reapportionment of all ESS energies within the fleet.

• Journal of Animal Science and Technology
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• 제54권6호
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• pp.401-409
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• 2012

The objective of this study was to determine genetic variation of five Korean native chicken lines using 30 microsatellite (MS) markers, which were previously recommended by ISAG (International Society for Animal Genetics). The initial study indicated that two microsatellite markers, MCW0284 and LEI0192, were not amplified in these lines and excluded for further analysis. Twenty eight microsatellite markers were investigated in 83 birds from five Korean native chicken lines. The identified mean number of alleles was 4.57. Also, the expected, observed heterozygosity (He, Ho) and polymorphism information content (PIC) values were estimated in these markers and they ranged from 0.31~0.868, 0.145~0.699, and 0.268~0.847, respectively. The results were used for the discrimination of five chicken lines using genetic distance values and also neighbor-joining phylogenetic tree was constructed. Based on the He and PIC values, eighteen markers are enough for the discrimination of these Korean native chicken lines for the expected probability of identity values among genotypes of random individuals (PI), random half sibs ($PI_{half-sibs}$) and random sibs ($PI_{sibs}$). Taken together, these results will help the decision of conservation strategies and establishment of traceability system in this native chicken breed. Also, the use of ISAG-recommended microsatellite markers may indicate that the global comparison with other chicken breeds is possible.

• 한국사회복지학
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• 제56권2호
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• pp.311-326
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• 2004

본 연구는 자활사업의 개입모델로서 사례관리를 제안하며 그 실천적 적용가능성을 살펴본다. 근로빈곤층을 대상으로 한 자활사업이 궁극적으로 탈빈곤의 효과와 함께 지역사회에서의 자립된 삶을 얻는 기회를 제공하기 위해서는 일자리제공을 통한 경제적 자활 뿐 아니라 지역사회에서 개인의 삶에 영향을 미치는 다양한 사회적 위험요인들에 대한 지지적 서비스가 필요하다. 이를 위해 본 연구에서는 자활이 갖는 실천적 의미와 사례관리의 필요성을 살펴보고 이에 적절한 사례관리의 유형과 사례관리자의 역할을 살펴본다. 또한, 자활사업에 필요한 사례관리의 개입방향-상황중심적 사고를 통한 통합적인 사례관리체계의 구성, 역량강화적 접근에 기초한 주체적인 참여와 자율적인 운영, 사회망 개발과 연대적 노력을 통한 포괄적인 사례관리 프로그램으로의 발전-을 제안함으로써 고용과 복지가 통합적으로 고려되는 자활사업의 틀을 구성하고자 한다. 본 연구는 자활사업대상자와 기관차원에서 활용할 수 있는 실천프로그램을 제시함으로써 정책적 차원에 그치던 자활사업에 관한 논의를 서비스제공 차원에서 구체화시킨다는 의의가 있다.

• 산업경영시스템학회지
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• 제43권2호
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• pp.87-97
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• 2020

The purpose of this study is to suggest the characteristics of online shopping malls and find a way to establish a differentiated marketing Strategy for online shopping malls in China. This study investigated the effect on the loyalty by applying the perceived shopping value (Hedonic Value, Utilitarian Value) of consumers in online shopping malls. In addition, In order to grasp the factors affecting consumer loyalty in online shopping malls, the characteristics of online shopping malls are multidimensional, consisting of product characteristics, recommended quality, benefit services, and community services. In order to obtain the purpose of the study, a questionnaire was surveyed for chinese online shopping experience and the research model was verified through empirical analysis method. Statistical analysis program was used together with SPSS 24.0 and AMOSS 24.0. Looking at the results of the analysis, firstly, the recommended quality and benefit service of online shopping malls are positive for the perceived hedonic value of consumers. The product characteristics and community service were found to have no effect on the hedonic shopping value. Secondly, the product characteristics, recommended quality, benefit service, and community service of online shopping malls on the utilitrian value perceived by consumers were positively affected. Thirdly, the perceived hedonic value has a positive effect on loyalty. Finally, it was confirmed that perceived utilitrian value affects loyalty. Based on the results of this study, a differentiated marketing strategy was established for existing chinese online shopping mall operators and potential new operators as well.

• Safety and Health at Work
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• 제13권1호
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• pp.9-16
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• 2022

Background: The global shift toward greener societies demands new technologies and work operations in the waste-management sector. However, progressive industrial methods do not necessarily consider workers' health. This study characterized workers' exposure to bioaerosols and investigated the bioaerosols' potential to engage the immune system in vitro. Methods: Full shift personal aerosol sampling was conducted over three consecutive days. Dust load was analyzed by gravimetry, fungal and actinobacterial spores were analyzed by scanning electron microscopy, and endotoxin by limulus amebocyte lysate (LAL) assay. In vitro exposure of HEK cells to airborne dust samples was used to investigate the potential of inducing an inflammatory reaction. Results: The total dust exposure level exceeded the recommended occupational exposure limit (OEL) of 5.0 mg/m³ in 3 out of 15 samples. The inhalable endotoxin level exceeded the recommended exposure level by a 7-fold, whereas the fungal spore level exceeded the recommended exposure level by an 11-fold. Actinobacterial spores were identified in 8 out of 14 samples. In vitro experiments revealed significant TLR2 activation in 9 out of 14 samples vs. significant TLR4 activation in all samples. Conclusion: The present study showed that the dust samples contained potentially health-impairing endotoxin, fungi, and actinobacterial levels. Furthermore, the sampled dust contained microbial components capable of inducing TLR activation and thus have the potential to evoke an inflammatory response in exposed individuals.

• 핵의학기술
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• 제27권2호
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• pp.95-98
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• 2023

Purpose: The precision error of a bone density meter reflects the equipment and reproducibility of results by an examiner. Precision error values can be expressed as coefficient of variation (CV), CV%, and root mean square-SD (RMS-SD). The International Society for Clinical Densitometry (ISCD) currently recommends using RMS-SD as the precision error value. When a 95% confidence interval is applied, the least significant change (LSC) value is calculated by multiplying the precision error value by 2.77. Exceeding the LSC value reflects a significant difference in measured bone density. Therefore, the LSC value of a bone density equipment is an essential factor for accurately determining a patient's bone density. Accordingly, we aimed to calculate the LSC value of a bone density meter (Lunar iDXA, GE) and compare it with the value recommended by the ISCD. We also assessed whether the value measured by the iDXA equipment was below the LSC value recommended by ISCD. Material and Methods: The bone densities of the lumbar spine and thighs of 30 participants were measured twice, and the LSC values were calculated using the precision calculation tool provided by the ISCD (http://www.iscd.org). To check the reproducibility of the measurement, patients were asked to completely dismount from the equipment after the first measurement; the patient was then repositioned before proceeding with the second measurement. Results: The LSC values derived using the CV% values recommended by the ISCD were 5.3% for the lumbar spine and 5.0% for the thigh. The LSC values measured using our bone density equipment were 2.47% for the lumbar spine and 1.61% for the thigh. The LSC value using RMS-SD was 0.031 g/cm² for the lumbar spine and 0.017 g/cm² for the thigh. Conclusion: that the findings confirm that the CV% value measured using our bone density meter and the LSC value using RMS-SD were maintained very stably. This can be helpful for obtaining accurate measurements during bone density follow-up examinations.

• 한국비블리아학회지
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• 제35권1호
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• pp.273-300
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• 2024

전자기록 환경에서는 아날로그 기록물의 디지털화 방안에 대한 논의와 함께, 전자적으로 생산, 접수된 기록물에 대한 유형별 보존전략 마련이 중요하게 인식된다. 같은 맥락에서, 문서유형 외 데이터세트, 시청각 유형 전자기록물의 장기보존을 목표로 보존포맷 선정체계를 적용하기 위한 논의가 필요하다. 시청각 기록물은 이미지, 오디오, 비디오와 같이 매체별 특성에 적합한 보존전략을 적용해야 한다. 본 연구는 시청각 중 오디오 유형 전자기록물의 보존포맷 선정을 위한 고유기준을 문헌 조사에 바탕을 둔 필수보존속성 분석을 통해 수립하고, 오디오 유형 보존포맷 적합성 평가항목을 구성하고 이를 적용한 결과를 토대로 권고포맷을 제안했다.

• 대한설비공학회지:설비저널
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• 제11권4호
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• pp.6-18
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• 1982

The performance of two typical types of solar hot water heating system was tested in Seoul. Types of systems studied are single-tank internal external heat exchanger system and single-tank internal heat exchanger system. Comparing to experimental results, a transient system simulation program was made to analyze the performance of the selected system. The climate data, Standard Weather Year for Seoul, required for the simulation was provided. Computer simulations were used to estimate the effect of significant parameters upon system performance. The followings are obtained. 1. In the domestic solar water Heating system, the value $20-40kg/m^2\;h$ for flow rate through the collector is much better than the recommended value $72kg/m^2\;h$ in the solar heating system. 2. The effectiveness of collector heat exchanger and storage tank size are found to have only a small effect upon system performance. 3. The hot water draw pattern has a significant effect on system performance. A higher system efficiency achieved when draw-off occurred around noon than when it occurred around early morning. Using the above results, the reference solar hot water system which provides $300\ell$ of hot water per day, was selected as a guide for designer. And simplified graphical method was developed based on the modified f-chart method to determine required collector area. When the system design parameters of the proposed system differs from the reference system, required collector area can be calculated from area adjustment factors.

• 대한지역사회영양학회지
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• 제3권5호
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• pp.748-758
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• 1998

The Recommended Dietary Allowances(RDAs, Nutrient standards), dietary guidelines, and food guides, each define aspects for a healthy diet in different ways. The RDA and food guide for Koreans were first established in 1962 by the Food and Nutrition Committee of the Korea FAO Association. The committee released the RDA and suggested ways to intake the recommended nutrients. Every five years, the committee has added more data and released revisions. The latest edition of the RDA is the 6th revision. In the beginning, the concept of basic food groups was emphasized as basic data for planning means based on RDA. In the 5th revision, the basic food groups and dietary guideline for public health from the Ministry of Health and Welfairs(December, 1990) suggests that, 1) Eat a variety of foods with a recommended fat intake equaling or less than 20% of total calories ; 2) Maintain ideal body weight and prevent obesity ; 3) Eat foods low in salt. Salt intake should not exceed 10g ; 4) Do not drink too much ; 5) Eat regularly and enjoy meals. After these guidelines were established, the first nutritonal education efforts guidelines were developed in 1984. Despite broad possibilities for application, they had limited use, mainly as a nutritional assessment and food balance sheet preparation. They were not well utilized in public nutritional education and nutritonal policy through the media because of the weakness of the government's food and nutriton policy. Also a lack of administrative support and dietitians in the health department and administrative organizations was partly to blame. In regard to public health and nutrition status, life expectancy has increased 10 years since the 70's and the elderly population increased threefold in 1995 compared to 1960. The common causes of death in 1996 by 19 Chapters classification, were first disease of the circulatory system ; the second, neoplasms ; the third, external causes fo mortality ; the forth, diseases of the digestive system ; and the fifth, respiratory system diseases, In food intake, grain and complex starch intake has decreased while fruit and animal foods have considerably increased. Therefore, energy from carbohydrates has decreased while energy from protein and fat has increased. Energy intakes from protein, fat and carbohydrates were respectively 12.5, 7.2 and 80.3% in 1969 but 16.1, 19.1 and 64.8% in 1995. 62.9% of the householes had the fat energy less than 20%, while 37.1% had the fat energy above 20%. The only intakes of vitamin A and calcium were below RDA levles. Therefore, nationwide attention should be focused on public nutriton education and public activities with supplementation of the RDAs, according to the food guide and the dietary guideline.

• 보존과학회지
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• 제37권5호
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• pp.440-450
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• 2021

수장고 및 전시 공간의 종합적 유해생물 관리를 위하여 실시간 온습도 센서 및 모듈을 이용한 환경 데이터 수집, 실내 부유 진균류 농도 및 곤충 유입 자료의 데이터 시각화를 부여 정림사지 박물관 유물 공간을 대상으로 실시하였다. 실시간 온습도 모니터링 시스템은 30분 단위로 측정 데이터를 수집하였으며 연동 애플리케이션을 통해 측정 데이터를 실시간으로 확인 가능하도록 하였다. 또한 측정된 온습도 데이터가 미리 설정한 범위를 초과하였을 경우, 푸시 알림을 담당자의 단말기로 전송하여 현황 정보를 제공함으로써 상시적 관리 체계를 구축하였다. 이를 통해 8월 중 유물 권장 온도 범위를 초과한 상황의 즉각적인 인지 및 조치가 가능하였다. 수장고 내부 공간에 따른 시기별 부유진균류 농도 데이터를 국립문화재연구소에서 제시한 생물학적 유해환경요인 권고기준(안) 기준으로 범례화하여 시각화한 결과, 수장고 1층과 2층 유물 공간 모두 위험 기준인 80 C.F.U./m³ 이하의 부유 진균류 농도가 유지되는 것이 확인되었다. 또한 곤충 유입 조사 결과, 수장고 내부에는 곤충이 포획되지 않았으며, 전시공간의 경우, 딱정그리마, 알락귀뚜라미, 알락꼽등이 등의 곤충이 포획되었다. 이를 바탕으로 구역별 포획 곤충의 개체 밀도에 따른 시각화를 실시한 결과, 곤충의 주요 유입 경로가 외부 출입구 및 화장실 구역임을 확인할 수 있었다.