• Journal of Microbiology and Biotechnology
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• 제21권11호
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• pp.1147-1150
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• 2011

Xanthomonas oryzae causes rice bacterial blight, which has been reported as one of the most destructive diseases of rice. Metabolites were identified through cheonggukjang, a traditional Korean fermented soybean product fermented by the Bacillus spp., to control the bacteria. HPLC, MS, and UPLC-Q-TOF-MS analyses were performed to identify metabolites responsible for antimicrobial activity. In this analysis, the m/z values of 253.0498, 283.0600, 269.0455, 992.6287, and 1,006.6436 were identified as daidzein, glycitein, genistein, surfactin B, and surfactin A, respectively. The levels of surfactin B and surfactin A were found to be high at 24 h (4.35 ${\mu}g$/ml) and 36 h (3.43 ${\mu}g$/ml) of fermentation, respectively.

• 스마트미디어저널
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• 제7권2호
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• pp.71-77
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• 2018

본 논문에서는 신재생에너지 발전과 연계한 에너지저장시스템(ESS)의 최적 운영을 위한 에너지관리시스템(EMS)의 구성요소 설계 시 고려할 기능, 운영 효과 분석과 전력요금 절감 방안을 제안한다. 이를 위해 태양광 발전 시스템에 리튬이온전지 기반의 배터리 시스템과 에너지관리시스템 연계 및 구축방안을 제시하고, 1년 동안 운영 데이터에 대한 분석한 결과를 기술한다. 또한 시스템 운영 효과를 높이기 위한 방안으로 EMS를 이용하여 최대수요 발생시간대의 피크전력을 경부하 시간대 충전전력으로 대체하여 ESS 전용 요금제에 따른 요금편익과 부하 평준화에 기여하는 효과를 제안한다.

• 전력전자학회논문지
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• 제4권6호
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• pp.523-530
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• 1999

본 논문은 전류형 GTO 컨버터의 SHE-PWN 실시간 제어기법을 제안한다. 제안된 방법은 변조지수에 따라서 실시간으로 GTO 스위치의 턴-온/오프 주기를 계산할 수 있도록 Loop-up Table을 선형화 하였다. 제안된 방법에 의해서 컨버터의 DC 출력전류를 빠르고 연속적으로 제어하면서 컨버터의 AC 입력전류 파형을 정현파로 유지하고 동시에 역률을 ‘1’로 제어할 수 있다. 본 논문에서 SHE-P주 선형화 기법과 고 역률 제어기법을 제안하고 이들 성능을 해석적으로 검토하였다. 시뮬레이션과 실험 결과로부터 제안된 기법의 타당성을 입증하였다.

• 한국정보처리학회논문지
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• 제7권11S호
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• pp.3613-3622
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• 2000

본 논문은 현재의 인터넷에서 IPv6 기반의 차세대 인터넷으로 진화하기 위한 연구 결과를 기술한다. IPv6 기반의 차세대 인터넷을 도입하기 위한 요구사항들을 분석하고, 이를 기반으로 기존 IPv4와 호환을 고려한 단계별 IPv6 도입 전략 개발, 본격적인 IPv6 도입 시 외국의 기술력에 의해 기술 피해 및 종속화를 막기 위한 핵심 기술 선정, 신규인터넷기관, ISP들이 IPv6 망을 단계별로 구축, 운용할 수 있도록 하기 위한 망 구축, 진화 방안, IPv6 공식주소의 체계 및 할당 방안, IPv6 관련 국제활동 강화 등을 포함하는 국내에서 IPv6 진화를 위해 필요한 내용들을 제안한다.

• 한국태양에너지학회 논문집
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• 제28권4호
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• pp.25-34
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• 2008

Since the atmospheric clearness index is main factor for evaluating atmosphere environment, it is necessary to estimate its characteristics all over the major cities in Korea Peninsula. We have begun collecting clearness index data since 1982 at 16 different cities in South Korea and estimated using empirical forecasting models at 21 different stations over the North Korea from 1982 to 2006. This considerable effort has been made for constructing a standard value from measured data at each city. The new clearness data for global-dimming analysis will be extensively used by evaluating atmospheric environment as well as by solar PV application system designer or users. From the results, we can conclude that 1) Yearly mean 63.5 % of the atmospheric clearness index was evaluated for clear day all over the 37 cities in Korea Peninsula, 2) Clear day's atmospheric clearness index of spring and summer were 64.6 % and 64.8 %, and for fall and winter their values were 63.3 % and 61.3% respectively in Korea Peninsula.

• 전력전자학회논문지
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• 제26권5호
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• pp.342-348
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• 2021

The PV module of solar power systems requires maximum power point tracking (MPPT) technique because the power-voltage and current-voltage characteristics vary depending on the surrounding environment. In addition, the 120 Hz ripple voltage on the DC-Link is caused by the imbalance of the system voltage and current. The effect of this 120 Hz ripple voltage reduces the efficiency of the power generation system by increasing the output current distortion rate. Increasing the capacity of DC-Link can reduce the 120 Hz ripple voltage, but this method is inefficient in price and size. We propose a technique that detects 120 Hz ripple voltage and reduces the effect of ripple voltage without increasing the DC-Link capacity through a controller. The proposed technique was verified through simulations and experiments using a 1 kW single-phase solar power system. In addition, the proposed technique's feasibility was demonstrated by reducing the distortion rate of the output current.

• 도시과학
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• 제8권1호
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• pp.7-14
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• 2019

Recently, interest in solar energy, which is the center of new government energy policy, is increasing. However, the focus is on mass production of solar power plants, and policies and related technologies for maintenance and management of existing installed PV modules are insufficient. In this study, we use UAV (Unmanned Aerial Vehicle) to acquire RGB and infrared images, apply it to the structure-from-motion (SfM) based image analysis tool, model the three- And the position of the hot spot was monitored and coordinates were detected. As a result, it is possible to provide basic spatial information for maintenance of solar module by monitoring and position detection of hot-spot suspected solar cells by superimposing infrared image and RGB image based on unmanned aerial vehicle.

• The Plant Pathology Journal
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• 제35권5호
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• pp.473-485
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• 2019

Kiwifruit (Actinidia spp.) is an economically important crop and a bacterial canker disease, caused by Pseudomonas syringae pv. actinidiae (Psa), is the most destructive disease in kiwifruit production. Therefore, prevent and control of the disease is a critical issue in kiwifruit industry worldwide. Unfortunately, there is no reliable control methods have been developed. Recently, interest in disease control using microbial agents is growing. However, kiwifruit microbiota and their roles in the disease control is mainly remaining unknown. In this study, we secured bacterial libraries from kiwifruit ecospheres (rhizosphere, endospere, and phyllosphere) and screened reliable biocontrol strains against Psa. As the results, Streptomyces racemochromogenes W1SF4, Streptomyces sp. W3SF9 and S. parvulus KPB2 were selected as anti-Psa agents from the libraries. The strains showed forcible antibacterial activity as well as exceptional colonization ability on rhizosphere or phyllosphere of kiwifruit. Genome analyses of the strains suggested that the strains may produce several anti-Psa secondary metabolites. Our results will contribute to develop biocontrol strains against the kiwifruit canker pathogen and the disease management strategies.

• 대한건축학회논문집:구조계
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• 제34권7호
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• pp.35-42
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• 2018

Semi-transparent Photovoltaics (STPV) works as an exterior material replacing windows as well as functioning as a electricity generator. As a result, it also affects the building's heating, cooling and lighting loads. In this study, we used the concept of Net Electricity Benefit(NEB) to conduct a parametric analysis of building energy impact of STPV. The NEB of STPV is from $-1kWh/m^2$ to $6kWh/m^2$. Since NEB represents the amount of energy increase or decrease when STPV is applied compared to the standard window, a value of 0 or less means that the demand for building energy can be increased rather than applying a general window having high thermal performance and high visible light transmittance value. Therefore, it is necessary to perform a comprehensive performance evaluation considering both the performance evaluation based on the existing power generation performance and the influence on the building energy.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.2883-2897
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• 2022

According to the Renewable Energy 3020 Implementation Plan announced in 2017 by the South Korean government, the electricity share of renewable energy will be expanded to 20% of the total electricity generation by 2030. Given the intermittency of electricity generation from renewable energy, realization of such a plan presents challenges to managing South Korea's isolated national electric grid and implies potentially large excess electricity generation in certain situations. The purpose of this study is: 1) to develop a model to accurately simulate the effects of excess electricity generation from renewables which would arise during the transition, and 2) to propose strategies to manage excess electricity generation through effective utilization of domestic electricity generating capabilities. Our results show that in periods of greater PV and wind power, namely the spring and fall seasons, the frequency of excess electricity generation increases, while electricity demand decreases. This being the case, flexible operation of coal and nuclear power plants along with LNG and pumped-storage hydroelectricity can be used to counterbalance the excess electricity generation from renewables. In addition, nuclear energy plays an important role in reducing CO₂ emissions and electricity costs unlike the fossil fuel-based generation sources outlined in the 8th Basic Plan.