• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.206-206
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• 2021

The necessity for appropriate management of water resources infrastructures such as reservoirs, levees, and dikes is increasing due to unexpected hydro-climate irregularities and rising water demands. To meet this need, past studies have focused on advancing theoretical optimization algorithms such as nonlinear programming, dynamic programming (DP), and genetic programming. Yet, the optimally derived theoretical solutions are limited to be directly implemented in making release decisions in the real-world systems for a variety of reasons. This study first aims to comparatively analyze the two prominent optimization methods, DP and evolutionary multi-objective direct policy search (EMODPS), under historical inflow series using K-fold cross validation. A total of six optimization models are formed each with a specific formulation. Then, one of the optimization models was coupled with the actual zone-based hedging rule that has been adopted in practice. The proposed methodology was applied to Boryeong Dam located in South Korea with conflicting objectives between supply and demand. As a result, the EMODPS models demonstrated a better performance than the DP models in terms of proximity to the ideal. Moreover, the incorporation of the real-world policy with the optimal solutions improved in all indices in terms of the supply side, while widening the range of the trade-off between frequency and magnitude measured in the sides of demand. The results from this study once again highlight the necessity of closing the gap between the theoretical solutions with the real-world implementable policies.

• The Korean Journal of Pain
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• 제18권2호
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• pp.181-186
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• 2005

Background: Hydromorphone has an intermediate lipid solubility range that falls between morphine and fentanyl. Lipophilic activity during opioid epidural administration is important in relation to both the side effects and analgesic efficacy. The purpose of this study was to compare epidural hydromorphone and fentanyl when concomitantly infused with bupivacaine in patients undergoing a thoracotomy. Methods: Seventy-seven thoracotomy patients, with patient-controlled epidural analgesia (PCEA), were blindly allocated into two groups [group F (n = 34); 0.1% bupivacaine and fentanyl $5{\mu}g/ml$, group H (n = 34); 0.1% bupivacaine and hydromorphone $16{\mu}g/ml$)]. The basal PCEA rate and demand dose were 4 ml/hr and 3 ml, respectively. The visual analogue scale (VAS) for pain, and pruritus, sedation and nausea were measured at 6, 12 and 24 hours after the operation. Results: There were no significant differences in the VAS pain scores and the incidences of pruritus, nausea and sedation between the two groups. The total infused volume after 24 hours was lower in H compared to that of F group (P < 0.05). Conclusions: We conclude that epidural hydromorphone or fentanyl administration has a similar analgesic efficacy and shows similar incidences of side effects, when concomitantly infused with bupivacaine, in the management of acute pain following a thoracotomy.

• 한국경영과학회지
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• 제17권1호
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• pp.117-117
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• 1992

Pubilc utility industries including the electric utility industry are facing a new stream of privatization com-petition with the private sector and deregulation. The necewssity to solve now and in the future power supply and demand problems has been increasing through the sophisticated generation expansion plan(GEP) approach con-sidering not only KEPCo's supply-side resources but also outside resources such as non-utility generation(NUG) demand-side management (DSM). Under the environmental situation in the current electric utility industry a new approach is needed to acquire multiple resources competitively. This study presents the development of a modified electric generation expansion analysis system(EGEAS) model with avoided cost based on the existing EGEAS model which is a dynamic program to develope an optimal generation expansion plan for the electric utility. We are trying to find optimal GEP in Korea's case using our modified model and observe the difference for the level of reliabilities such as the reserve margin(RM) loss of load probability(LOLP) and expected unserved energy percent(EUEP) between the existing EGEAS model and our model. In addition we are trying to calculate avoided cost for NUG resources which is a criterion to evaluate herem and test possibility of connection calculation of avoided cost with GEP implementation using our modified model. The results of our case study are as follows. First we were able to find that the generation expansion plan and reliability measures were largely influenced by capacity size and loading status of NUG resources, Second we were able to find that avoided cost which are criteria to evaluate NUG resources could be calculated by using our modified EGEAS model with avoided cost. We also note that avoided costs were calculated by our model in connection with generation expansion plans.

• 한국인터넷방송통신학회논문지
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• 제19권2호
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• pp.187-192
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• 2019

수요관리와 정전에 대한 비상전원 기능을 갖춘 하이브리드 전력저장시스템으로 비상발전설비가 필요한 빌딩 및 공장건축 시에 투자비를 최소화하고, 상시 전력비를 절감함으로서 경제성을 확보할 수 있 기술을 개발함으로써 새로운 비즈니스 모델을 제시한다. 평상시에 STS(Static Transfer Switch)를 통해 부하에 계통 전력을 공급하고 PCS는 계통에 병렬로 연계되어 수요관리를 수행한다. EMS는 수요예측을 통한 전력의 효율적 운용을 위해 ESS에 충방전 지령을 PMS(Power Management System)로 하달하고 PMS는 다시 PCS 제어기로 지령을 전달하여 시스템을 운용한다. 정전시에는 STS가 계통으로부터 빠르게 이탈되면서 PCS는 독립 전원이 되어 부하 측에 정전압/정주파수의 전력을 공급할수 있는 구조이다. 따라서 하이브리드 ESS에 대한 실 계통 연계 및 독립 운전 성능 검증을 통한 신뢰성을 확보할수 있고, 저탄소 녹색성장 기술의 효율적 전력망과 연계 운영이 가능하게 함으로써 ESS 연계를 통한 신재생에너지 발전에 의한 불규칙한 전력 품질개선, 피크부하 기여도 제고가 가능하다. 또한 현재 석탄 화력이 담당하고 있는 주파수추종 예비력을 ESS로 대체함에 따라 연료비가 높은 LNG 발전기 가동비용을 절감할 수 있는 기대효과가 있다.

• 가정과삶의질연구
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• 제13권4호
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• pp.199-213
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• 1995

Multi-religious situation with one of the greatest characteristics in Korea society is forming the basic to induce the conflict among the religious, The outline of the research is as follows; 1. The religious conflict are occurred between Christiianity and Buddhism·Shamanism·Nonchurch 2. The problems of sacrificial rite oneself's persistent demand for religion and the other side's disallowance against the religion and so on are indicated as one of the complication problems with the heaviest weights. 3. The power structure in family the status of branch family the rank of sibling oneself's religion and so on are related as major variables which influence the religious conflict. 4. The outcomes from religious conflict are forming on tacit consent boycott discontinuation frequent quarrels and so on. 5. Most of the persons concerned about the religious conflict are put a great value on both home and religion and they are endearing for the harmony of them.

• 전기학회논문지
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• 제60권8호
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• pp.1451-1459
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• 2011

Recently, low energy houses have become an essential issue globally and various subsidy programs are ongoing to penetrate. All-electric houses which are another type of low energy houses or zero carbon houses are being developed. These houses consider new & renewable energy and demand side management programs in the construction and the diffusion process because these programs are essential policies to use energy resources reasonably. This paper shows a simulation methodology to control home appliances in all-electric houses considering the electricity consumption pattern of residents. The simulation is a first step to estimate energy saving of the house in a practical manner.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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• pp.447-449
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• 2008

미래에 예측되는 수요를 보다 바람직한 방향으로 개선하고자 시행하는 제반활동을 의미하는 전력수요관리는 고유가와 온실가스 문제가 큰 현안이 된 지금의 상황에 비추어 볼 때 그 중요성이 날로 커지고 있다고 할 수 있다. 그러나 현재의 수요관리 시스템은 하계의 수급문제 해결에 그 초점이 맞춰져 있으며, 현재 문제가 되고 있는 동계 전력수급문제에 대해서는 특별한 관리 대책이 없는 상황이다 따라서 동계 수요관리를 위한 수요관리자원 발굴 작업이 시급하며, 그 대책중의 하나로 PV(Photovoltaics) DSM(Demand Side Management)를 제안하고, 실제 건물에 적용 시 그 효과에 대하여 알아보았다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.393-396
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• 2007

Recently one level higher intelligent switching board than established one by the application of intelligent building and digital system are being constructed. Therefore facility's high efficiency, high degree satisfaction, miniaturaization, standardization through application of communication technology and monitoring and controlling by computer system utilized by web-basis power control system and electric IT are practiced. Especially network must be constructed through unified IBS server that monitors every educational institute's switching boards in real time control system. And I intend to create methods to save energy and raise electricity quality by power demand prediction and remote-controled management and operation. In this thesis I intend to suggest measures of forming unified system through researching educational institute's ways of constructing switching board and status analysis and overcoming technical difficulties in user's side and saving and maintenance expense.

• 조명전기설비학회논문지
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• 제27권2호
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• pp.7-13
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• 2013

The portion of lighting power consumption for our country is up to 20~30% of the total amount. Currently, most of the DSM(Demand side management) of lighting power is delivered in supply of high efficient lighting to customers. On the contrary, applications of lighting power to power load leveling are still rare. In this paper, the simulations for various control types of lighting power for load leveling are tried, and we obtained the cost effective and optimal control method through that. This simulation was executed in test office with fluorescent light by us based on applying 8 control types(on, off & dimming), considering customers' satisfaction, for instance, minimum intensity of illumination allowed. According to the result of this test, we found that mixed type(chessboard(on-off) plus dimming control(10%)) is most effective.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.264-265
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• 2006

This paper presents direct load control algorithm based locational and electric load characteristics. Direct load control is defined that demand-side management program activities that can interrupt consumer load at the time of annual peak load by direct control of the utility system operator by interruption power supply to individual appliances or equipment on consumer premises. Korean power system is divided into 14-areas considering branches operating in KEPCO, and electric loads are classified into 19 load groups considering interruption costs in this paper. The purpose of proposed method is to decrease social losses by controlling electric loads mainly whose interruption costs are low. It is expected that the proposed algorithm can be used as the countermeasure for the emergency state of the electric power dispatch in a operation point of view.