• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1345-1356
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• 2021

Damage to nuclear power plants causes human casualties and environmental disasters. There are electrical facilities that control safety-related devices in nuclear power plants, and seismic performance is required for them. The 2016 Gyeongju earthquake had many high-frequency components. Therefore, there is a high possibility that an earthquake involving many high frequency components will occur in South Korea. As such, it is necessary to examine the safety of nuclear power plants against an earthquake with many high-frequency components. In this study, the shaking table test of electrical facilities was conducted against the design earthquake for nuclear power plants with a large low-frequency components and an earthquake with a large high-frequency components. The response characteristics of the earthquake with a large high-frequency components were identified by deriving the amplification factors of the response through the shaking table test. In addition, safety of electrical facility against the two aforementioned types of earthquakes with different seismic characteristics was confirmed through limit-state seismic tests. The electrical facility that was performed to the shaking table test in this study was a motor control center (MCC).

• KIEE International Transactions on Power Engineering
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• 제11A권4호
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• pp.45-50
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• 2001

The impact evaluation of a DSM program is a very important issue since the results are used to determine the sustainability of a program. In general. to estimate the impacts of a DSM program it is required to measure the electricity usage changes before and after a program. Since the measurement-based approaches cost highly, most of the conventional evaluations are based on the average figures. However estimation of the average-based impacts can lead to both distorted results of over/under estimation of kW and kWh savings and non-optimal DSM planning. In this paper, we have developed a new multi-point measurement approach which can evaluate kW and kWh savings of a DSM program more exactly. To do this, the saving rate and operating rate are defined and set as the function of load factor of a customer, and these rates are incorporated with the conventional diffusion function of Bass to project the future impacts of a DSM program. The case study is performed on the inverter program of Korea by using the suggested approach.

• 전력전자학회논문지
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• 제25권4호
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• pp.243-250
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• 2020

Energy harvesting is a recent technology involving the harvest and utilization of extremely small surrounding energy. Energy harvesting research is conducted in various fields. Triboelectric nanogenerators (TENGs) are energy harvesting technologies that use static electricity generated by physical movement or friction. Although TENGs generate output power in microwatt levels, they experience high internal impedance compared with other energy harvesting generators, thereby making the continuous transfer of electric power to loads difficult. This study proposes a power management system for TENGs that consists of three stages, that is, an AC/DC rectifier, an impedance coupler switch with a capacitor bank, and a DC/DC converter. In addition, the selection method of the AC/DC rectifier and DC/DC converter is proposed to maximize the amount of power transferred from energy harvesting areas. Furthermore, the impedance coupler switch and capacitor bank are discussed in detail. The validity and performance of the proposed three-stage power management system for TENGs are verified using a prototype system.

• 조명전기설비학회논문지
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• 제14권1호
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• pp.59-66
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• 2000

최근 산업공정 시스댐이 복잡해지고 고도의 성능을 요구함에 따라 PLC의 하드혜어와 소프트웨어의 성능이 향상되었다. SFC 그래픽 언어는 순차 논리 알고리즘을 기술뿐만 아니라 인터록 제어 알고리즘과 같은 에러 관리 알고리즘을 기술하는 데에도 적합하다. 본 논문에서는 산업 공정 제어 시스템을 기술하는데 있어서 효과적으로 에러를 관리하기 위해 제한자를 이용 한 에러 관리 방법올 제안하였으며, 제안된 방법으로 필름 코탱기 제어 시스템을 구현한 결과 에러 관리가 용이하고 프로그랩 메모리의 용량을 줄일 수 있었음을 확인하였다.

• 조명전기설비학회논문지
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• 제22권6호
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• pp.134-140
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• 2008

국내 전력시장에서 현 혼잡처리방법은 혼잡비용(congestion cost)을 부가비용(uplift)형태로 전력 사용량에 비례하여 시장 전체의 모든 소비자가 부담하고 있다. 반면 다수의 해외 전력시장에서 채택하고 있는 지역한계가격 (Locational Margnal Pricing)방식은 혼잡으로 인한 비용을 시장 참여자들에게 차등적으로 배분하고 있다. 현재 국내 전력시장에서는 송전 혼잡처리방법의 변경으로 인한 시장참여자 수익에 미치는 영향에 대한 체계적인 연구가 미흡한 실정이다. 본 논문에서는 혼잡처리방법의 변경이 국내 전력시장의 소비자 비용과 발전기 잉여에 미치는 영향에 대해서 분석한다.

• 한국수산과학회지
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• 제52권5호
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• pp.524-533
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• 2019

Sea urchins are hugely destructive of marine forest ecosystems. This study aimed to determine the behavioral response of purple sea Urchins Heliocodaris crassispina to food and an electrical stimulus and to investigate the attraction radius of these stimuli, with an eye to the development of technology for controlling sea urchin numbers. Ten purple sea urchins, housed in circular acrylic tank, were tested against various attractant stimuli. In addition, an experiment was conducted with 200 purple sea urchins in a large water tank to observe movement patterns and the attractiveness of various stimuli. In the smaller experiment, eight out of 10 sea urchins were attracted to food, and these attractive effects were maintained in all except one of the affected urchins. However, the attractant effects of the electrical stimulus were maintained in only three sea urchins. The results of the larger experiment indicated that differences in the attractant power of food and an electrical stimulus were 54%-78%, and approximately 5-15% of sea urchins were attracted by the electrical stimulus.

• 전기학회논문지
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• 제64권5호
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• pp.779-785
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• 2015

Recently, home energy management system (HEMS) for power consumption reduction has been widely used and studied. The HEMS performs electric power consumption control for the indoor electric device connected to the HEMS. However, a traditional HEMS is used for passive control method using some particular power saving devices. Disadvantages with this traditional HEMS is that these power saving devices should be newly installed to build HEMS environment instead of existing home appliances. Therefore, an HEMS, which performs with existing home appliances, is needed to prevent additional expenses due to the purchase of state-of-the-art devices. In this paper, an intelligent inference algorithm for EMS at home for non-power saving electronic equipment, called legacy devices, is proposed. The algorithm is based on the adaptive network fuzzy inference system (ANFIS) and has a subsystem that notifies retraining schedule to the ANFIS to increase the inference performance. This paper discusses the overview and the architecture of the system, especially in terms of the retraining schedule. In addition, the comparison results show that the proposed algorithm is more accurate than the classic ANFIS-based EMS system.

• 전기학회논문지
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• 제57권11호
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• pp.2117-2123
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• 2008

This paper describes the portal system architecture of large consumers for ESP(Energy Service Provider) to provide customers with various value added services such as monitoring and controlling a wide variety of electric devices in consumer's premises for optimal energy management from both consumer side and ESP side, and the prototype implementation of 2 kinds of value added services. The architecture is composed of the device portal which gathers the information from electric devices and controls them and the consumer portal which can make ESP operate the optimal energy management with two-way communications. The demand side management and energy management functions was chosen and implemented for the prototype system as value added services. The prototype was designed to create, manage, and trace the events about services between ESP and customers.

• 전기학회논문지
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• 제57권5호
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• pp.741-747
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• 2008

This paper proposes a new concept of IDSP(Intelligent Digital Switchgear Panel) which can solve the problem of the safety, the reliability and the convenience to correspond to the requirement of the general electric customer or electric power company under the ubiquitous-based home automation environments. By analyzing their requirement functions, a 32-bit micro processor is adopted as main controller to support the designed functions efficiently. The DSP-based single phase power management device is utilized to collect the electric power information and the ethernet convertor to communicate through internet among the IDSPs and the remote computer system. In the proposed IDSP, the several functions are implemented such as the earth leakage level display and waveform transmission, the electric fee display, the voltage management, the load management and the load control function. Finally, the prototype of the IDSP is made experimently based on the designed results, and then the effectiveness is verified by testing its basic functions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권3호
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• pp.508-522
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• 2011

Femtocell is an economical solution to provide high speed indoor communication instead of the conventional macro-cellular networks. Especially, OFDMA femtocell is considered in the next generation cellular network such as 3GPP LTE and mobile WiMAX system. Although the femtocell has great advantages to accommodate indoor users, interference management problem is a critical issue to operate femtocell network. Existing OFDMA resource management algorithms only consider optimizing system-centric metric, and cannot manage the co-channel interference. Moreover, it is hard to cooperate with other femtocells to control the interference, since the self-configurable characteristics of femtocell. This paper proposes a novel interference-aware resource allocation algorithm for OFDMA femtocell networks. The proposed algorithm allocates resources according to a new objective function which reflects the effect of interference, and the heuristic algorithm is also introduced to reduce the complexity of the original problem. The Monte-Carlo simulation is performed to evaluate the performance of the proposed algorithm compared to the existing solutions.