• 한국비블리아학회지
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• 제32권1호
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• pp.199-221
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• 2021

우리나라 대학도서관에서는 미국과 달리 지정자료 및 e-Reserve 서비스 운영이 매우 저조한 실정이다. 본 연구는 국내 대학도서관의 e-Reserve 서비스 활성화를 위한 기초 자료를 제공하기 위하여 미국 131개 대학도서관의 e-Reserve 서비스 운영 사례를 살펴보았다. 운영 사례를 확인하기 위하여 131개의 대학도서관 웹사이트를 조사하였으며 중에서 7개 대학도서관의 e-Reserve 서비스 운영 방식을 비교 분석하고, 4개의 e-Reserve 지원 소프트웨어의 기능을 확인하였다. 연구결과는 국내 대학도서관에서 e-Reserve 서비스를 운영하는데 있어 참고자료로 활용될 수 있을 것이며 분석한 지원 소프트웨어의 기능은 시스템 도입 시 고려할 기능요건이 될 것으로 판단된다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제25권4호
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• pp.283-292
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• 2022

Purpose: The prevalence of eosinophilic esophagitis (EoE) has been on the rise since it was first described in the 1990s. Several diseases and exogenous factors have been associated with EoE. Our aim was to investigate the epidemiology of EoE in cystic fibrosis (CF) patients. Methods: We identified individuals with CF from September 2014 to September 2019 within a database (IBM Explorys Solutions, Inc.). The prevalence of EoE in patients with CF was compared to the general population. Results: The database included 36,111,860 patients during the 5-year study period: 12,950 with CF (0.036%) and 28,090 with EoE (0.078%). EoE prevalence was higher in CF patients than the general population (46 in 10,000 vs. 7.8 in 10,000, p<0.001). Patients with CF and EoE were more likely to be male (50% vs. 33.5%, p<0.008), children (33.3% vs. 16.5%, p<0.001), and non-Hispanic (100% vs. 88.7%, p<0.001) than CF patients without EoE. CF with EoE patients were more likely to be children than EoE only (33.3% vs. 10.5%, p<0.001). Allergic conditions were generally more prevalent in CF with EoE than CF only (83.3% vs. 68.3%, p=0.01) and EoE only (83.3% vs. 69.3%, p=0.014). Conclusion: EoE is nearly 6-times more prevalent in CF patients. Those patients had higher incidence of other atopic conditions. EoE must be considered in the differential diagnosis of patients with CF presenting with dysphagia, refractory gastroesophageal reflux, vomiting, and other esophagus-related symptoms.

• 전기학회논문지
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• 제66권1호
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• pp.1-6
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• 2017

Total capacity of pumped hydro storage(PHS) in Korean power system reaches 4,700MW, though the share of it is about 4.56% of total capacity The Unit Commitment program, E-terracommit which is used for the operational purpose by KPX, includes the PHS model. But the model has a defect that it does not include the information of water level of upper reservoir. Therefore two types of improved the PHS models are represented in this paper. The first model is a optimized model by connecting the upper reservoir water level to the non-spinning reserve. The other model is to have priority allocate both the PHS and combined cycle generator for non-spinning reserve. The proposed two models and the E-terracommit model is compared and resulting to have improvement in estimating non-spinning reserve when using the proposed models.

• 한국전자거래학회지
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• 제9권2호
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• pp.17-31
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• 2004

인터넷 경매 시스템에서는 물품의 판매자가 경매 물품에 적합한 낙찰 예정가를 제안하는 것이 매우 중요하다. 최근에 정보검색 이론의 사례 유사도에 기초하여 경매 물품의 낙찰 예정가를 자동으로 생성하는 에이전트가 연구되었다. 그러나, 이것은 과거의 경매 물품 전체를 대상으로 가장 유사한 사례의 낙찰가를 낙찰 예정가로 생성하므로, 최근의 추세를 반영한 가격을 생성하지 못하는 단점 이 있다. 본 논문에서는 이러한 문제점을 해결하고자 시계열 분석에서 사용하는 이동 평균을 이용하여 최근의 경매 자료에 높은 가중치를 부여하여 낙찰 예정가를 생성하는 방법을 제안한다. 성능 실험을 통하여, 새로운 방법 이 판매자가 경매 물품에 대하여 불합리한 낙찰 예정가를 제시하는 것을 방지함으로써 낙찰률을 높일 수 있음을 보인다.

• 한국전자거래학회지
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• 제7권2호
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• pp.55-68
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• 2002

Internet group buying systems have been widely used recently. In those systems, because the reserve price is provided by the buyer, the success rate can be decreased if the reserve price is set too low compared with the normal price. Otherwise, an unsuitable successful bid can be made if the reserve price is set too high based on inaccurate information. Likewise, the seller's providing too high a bid price can deteriorate his/her own successful bid rate, whereas a successful bid with too low a price may make no profit in the sale. Therefore, pricing agents that recommend adequate prices based on the past buying and selling history data can be helpful. In this paper, we propose two kinds of agents. One suggests reserve prices to buyers based on the past buying history database of the system. The other recommends bid prices to a seller based on the past bidding history data of the company using the cost accounting theory. Through performance experiments, we show that the successful bid rate can increase by preventing buyers from making unreasonable reserve prices. Also, we show that, for the seller, the rate of successful bids with appropriate profits can increase. Using the pricing agents, we design and implement an XML-based group buying system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.924-926
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• 2004

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.417-419
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• 2005

This paper presents the effects and the regional power distribution of an increase or a decrease of a power reserve by load flow calculations under seasonal load patterns of each country for the future power shortages faced by the metropolitan areas or by the southeastern area of the South Korea in North-East Asia. In these connections, the types of a power transmission for interconnection consist of the 765kV HVAC and the HVDC. In this paper, the various cases of the power system interconnections in Far-East Asia are presented, and the resulting interconnected power systems are simulated by means of a power flow analysis performed with the PSS/E 28 version tool. The power flow map is drawn from data simulated and the comparative study is done. In this future, a power flow analysis will be considered to reflect the effects of seasonal power exchanges And the plan of assumed scenarios will be considered with maximum or minimum power exchanges during summer or winter in North-East Asia countries.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.46-47
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• 2008

전력산업은 국가경제 및 국민생활의 기반이 되는 기간산업으로서 그 역할이 중대하므로 계통운영자는 적정 예비력을 확보하여 양질의 전기를 안정적이고 효율적으로 공급해야 한다. 그러나, 계통규모의 지속적인 증가와 전력수급의 지역적 편중 가속화로 국내 여건은 갈수록 악화되고 있는 실정이다. 또한, 현행 예비력 기준은 계통규모와는 상관없이 정량적으로 확보하게 되어 있으며 예비력 소진시 재 확보해야 할 기준도 마련되어 있지 않다. 따라서, 본 논문에서는 지역적 계통특성을 반영하고 항목별 예비력 기준을 세분화하여 보다 체계적인 예비력 운영기준을 제시하고자 한다.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2004년도 e-Biz World Conference
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• pp.271-284
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• 2004

Rapid developments in computing and communication technology have made broadband Internet service over the wireless phone networks possible. This so-called 3G (third generation) mobile services promise to usher us into an era of a seamless marriage between Internet data and mobile phone services. However,

• 전기학회논문지
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• 제60권5호
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• pp.921-928
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• 2011

This paper presents a new method of local voltage control to achieve coordinative control among UPFC(Unified Power Flow Controller) and conventional reactive compensation equipments, such as switched-shunt and ULTC(Under-Load Tap Changing) transformer. Reactive power control has various difficult aspects to control because of difficulty of system analysis. Recently, the progress of power electronics technologies has lead to commercial availability of several FACTS(Flexible AC Transmission System) devices. The UPFC(Unified Power Flow Controller) simultaneously allows the independent control of active and reactive power flows as well as control of the voltage profile. When conventional reactive power sources and UPFC are used to control system voltage, the UPFC reacts to the voltage deviation faster than the conventional reactive power sources. Keeping reactive power reserve in an UPFC during steady-state operation is always needed to provide reactive power requirements during emergencies. Therefore, coordination control among UPFC and conventional reactive power sources is needed. This paper describe the method to keep or control the voltage of power system of local area and to manege reactive power reserve using PSS/E with Python. The result of simulation shows that the proposed method can control the local bus voltage within the given voltage limit and manege reactive power reserve.