• International Journal of Computer Science & Network Security
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• 제22권5호
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• pp.1-4
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• 2022

The growth in global population and industrialization has led to an increasing demand for electricity. Accordingly, the electricity providers need to increase the electricity generation. Due to the economical and environmental concerns associated with the generation of electricity from fossil fuels. Alternative power recourses that can potentially mitigate the economical and environmental are of interest. Renewable energy resources are promising recourses that can participate in producing power. Among renewable power resources, solar energy is an abundant resource and is currently a field of research interest. Photovoltaic solar power is a promising renewable energy resource. The power output of PV systems is mainly affected by the solar irradiation and ambient temperature. this paper investigates the utilization of machine learning unsupervised neural network techniques that potentially improves the reliability of PV solar power systems during integration into the electrical grid.

• 정보처리학회논문지C
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• 제10C권7호
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• pp.923-928
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• 2003

본 논문은 그리드 네트워크의 패킷 지연시간단축을 위한 병목 링크 대역폭 측정 알고리즘을 제안하고자 한다. 병목 링크 대역폭 측정방법으로 packet pair 알고리즘과 Paced Probes가 있으나 이들은 pacer 패킷으로 cross traffic의 영향을 줄이면서 Paced probe 패킷들이 링크를 지날 때 발생하는 시간 차이를 이용하여 병목 링크 대역폭을 구한다. 그러나 경로상의 병목 링크 대역폭을 측정할 뿐이지 병목현상이 발생한 지점은 알 수 없는 문제점이 있다. 이를 hop-by-hop 측정에 기반한 병목 대역폭 측정을 제시하여 그리드 네트워크에서 전체적인 패킷 지연 개선을 이룰 수 있다. hop-by-hop의 병목 대역폭을 측정하기 위해 paced probe 패킷에 타임스탬프 옵션을 이용하며 병목현상 해소를 통하여 패킷 전송 지연의 단축을 시뮬레이션을 통해 알 수 있다. 본 논문에서 제시한 알고리즘으로 병목 링크의 대역폭과 위치를 파악하여 그리드 ETP나 실시간 QoS를 보장하는 데이터 전송에 기여할 것으로 기대된다.

• 한국지리정보학회지
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• 제5권3호
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• pp.19-32
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• 2002

지형 정보는 표고 자료가 요구되는 응용에서 반드시 필요한 중요한 자료이다. 이러한 응용에는 배수 유역, 하천망의 추출, 가시권 분석, 지형학적 특징의 분석, 지형에 관련된 산사태 유형의 양적인 분석 및 산사태 발생지역에서 민감도 분석을 위한 지형 위치의 검증 등이 있다. 그러므로 DEM으로부터 추출된 지형 매개변수 자료의 정확도를 연구해야 한다. 본 연구에서는 표고 격자 DEM을 이용하여 자료원과 격자크기가 지형 매개변수에 미치는 영향을 분석하고자 하였다. 지형매개변수 분석은 수치지형도로 구축된 것과 DTED DEM을 이용하여 배수유역, 유역경사, 하천망을 추출하여 비교하였다. 특히, 격자 DEM으로부터 하천망을 추출하는 경우 DEM 격자크기에 관계없이 흐름누적 임계값에 따라 많은 영향을 받았다. 따라서 본 연구에서는 두 자료원에 동일한 흐름누적 임계값을 적용하여 하천망을 비교 분석하였다.

• IEIE Transactions on Smart Processing and Computing
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• 제5권1호
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• pp.35-42
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• 2016

Developments in power electronics have enabled the widespread application of Pulse Width Modulation (PWM) inverters, notably for connecting renewable systems to the grid. This study demonstrates that a high-quality power can be achieved using a stand-alone inverter, whereby the comparison between the power quality of the stand-alone inverter with battery storage (off-grid) and the power quality of the utility network is presented. Multi-loop control techniques for a single phase stand-alone inverter are used. A capacitor current control is used to give active damping and enhance the transient and steady state inverter performance. A capacitor current control is cheaper than the inductor current control, where a small current sensing resistor is used. The output voltage control is used to improve the system performance and also control the output voltage. The inner control loop uses a proportional gain current controller and the outer loop is implemented using internal model control proportional-integral-derivative to ensure stability. The optimal controls are achieved by using the Sisotool tool in MATLAB/Simulink. The outcome of the control scheme of the numerical model of the stand-alone inverter has a smooth and good dynamic performance, but also a strong robustness to load variations. The numerical model of the stand-alone inverter and its power quality are presented, and the power quality is shown to meet the IEEE 519-2014. Furthermore, the power quality of the off-grid system is measured experimentally and compared with the grid power, showing power quality of off-grid system to be better than that of the utility network.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.396-397
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• 2015

With the increasing utilization of high-voltage, direct current (HVDC) transmissions in modern power systems, the DC grid is becoming a hot topic in academic and practical systems. In the DC grid, one of the urgent problems is the fast clearance of the DC fault in the DC network. One preferred method is to isolate the faulty point from the DC network in a short time. The DC circuit breaker is to interrupt the overcurrent after DC faults occur. In this paper, a self-excited resonant DC circuit breaker is an easy and cheap equipment to interrupt the DC fault current. The Mayr's arc model is utilized to simulate the self-excited DC circuit breaker in a DC test system in PSCAD/EMTDC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1094-1095
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• 2015

The costs of installation, loss, and energy not supplied energy for submarine cable of offshore wind power plant (OWPP) are very high because the level of technology is still in the early stage as well as because of the marine environments. Therefore, reducing the total costs of a grid network for OWPPs is very important for financial feasibility. In particular, it is needed to minimize the project cost for optimizing the grid design and offshore substation location of a OWPP. The suggested method can reduce the total system cost and make it lower compared with existing methods.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.294-297
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• 2014

A Shipboard power system consists of three or four diesel generator sets connected to a grid. In case of dual fuel diesel generator sets employed LNG ship as a prime mover, large amounts of electricity are required for electric propulsion, auxiliary machinery and accommodation facilities. The electrical connection between generators through a network, torsional vibration can lead power swings. In this paper, the influence on the network by the torsional vibration of diesel generator sets in grid operation were studied. The torsional vibration characteristics were investigated and analyzed through theoretical analysis and the vibration measurement and the results were presented.

• 한국전자통신학회논문지
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• 제7권1호
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• pp.97-105
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• 2012

특허, 논문, 연구 주제에서 중복을 피하기 위해서 많은 연구자들은 다양한 방법을 가지고 특허와 이전의 연구 결과들을 검토한다. 이러한 노력을 줄이기 위하여 본 논문에서는 스마트 그리드에서 중복을 피하고 연구자들을 도와주기 위한 방법으로 수준지수분석, 국제협력 연구 네트워크, 소속과 저자의 핵심 분석을 통한 계량정보분석 방법을 제안한다.

• International Journal of Computer Science & Network Security
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• 제22권4호
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• pp.101-110
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• 2022

Histopathological analysis of biopsy specimens is still used for diagnosis and classifying the brain tumors today. The available procedures are intrusive, time consuming, and inclined to human error. To overcome these disadvantages, need of implementing a fully automated deep learning-based model to classify brain tumor into multiple classes. The proposed CNN model with an accuracy of 92.98 % for categorizing tumors into five classes such as normal tumor, glioma tumor, meningioma tumor, pituitary tumor, and metastatic tumor. Using the grid search optimization approach, all of the critical hyper parameters of suggested CNN framework were instantly assigned. Alex Net, Inception v3, Res Net -50, VGG -16, and Google - Net are all examples of cutting-edge CNN models that are compared to the suggested CNN model. Using huge, publicly available clinical datasets, satisfactory classification results were produced. Physicians and radiologists can use the suggested CNN model to confirm their first screening for brain tumor Multi-classification.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.120-122
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• 2004

This paper analyse impacts of Community Energy System (CES) on the grid during transition periods for integrating of the CES and the grid. In the near future, CES might be one of major energy supply structures. The basic concept of CES is that it supplies electrical and thermal energy to the local customer loads through the islanded power network separated from the grid. Therefore, the interconnection with the grid occurs only when the energy supply from the CES generators does not meet the demand of the local load. For avoiding impacting the grid during the transition operation modes of CES, it is necessary to thoroughly analyse the influences on the grid during those periods. In order to show them, in this paper, we model the CES with 2.34 WVA DG and simulate the impacts on the grid due to interconnection of CES The simulation results show that, in order to reduce bad influences of CES on the grid, CES need the efficient load management and generation control schemes during the transition periods.