• 농촌계획
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• 제29권4호
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• pp.55-67
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• 2023

This study investigated the correlation between impervious surface area rate(ISAR) and various urbanization indicators at the si-gun administrative level. For the years 2017 and 2021, we built correlation matrices to examine the relationships between ISAR and eight urbanization indicators, including total population, working-age population, residential power consumption, non-agricultural power consumption, paved road length, permitted development area, numbers of registered vehicles, and cadastral 'Dae' parcel area. Additionally, K-means clustering was employed to classify the 229 si-guns based on the ISAR change patterns. The analysis revealed a significant positive correlation between ISAR and urbanization indicators for both years studied. However, the interannual comparison showed a noticeably weaker correlation between changes in ISAR and urbanization indicators from 2017 to 2021. The K-means analysis also showed that si-guns with higher ISAR values, typically urban areas, demonstrated a weaker correlation, while the cluster consisting mostly of rural areas with lower ISAR displayed stronger correlations. These results suggested that ISAR should be a significant factor for consideration in sustainable rural planning and development strategies.

• 문화기술의 융합
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• 제7권2호
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• pp.345-350
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• 2021

넓은 지역에 설치되는 센서 네트워크 시스템은 유지 관리가 문제가 되어 왔으며, 이를 해결하기 위해 로봇을 사용하여 센서 네트워크에 에너지를 공급하려는 연구가 여러 연구자에 의해 수행되었다. 이 연구에서는 전력을 공급하는 노드들과 그 주변의 센서 노드들로 이루어진 센서 네트워크에 여러 대의 로봇을 사용하여 에너지를 공급하는 문제에서, 로봇이 최소 거리를 이동하도록 수정된 k-means 알고리즘을 사용하여 각 로봇이 작업할 영역을 분할하는 방법을 제안한다. 로봇의 에너지 전달률을 변수로 한 시뮬레이션 실험을 통해 분할된 각 영역의 센서 노드들이 동작을 유지할 수 있음을 보임으로써 제안한 수정 k-means 알고리즘의 타당성을 검증한다.

• International Journal of Computer Science & Network Security
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• 제22권10호
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• pp.177-182
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• 2022

Technology is progressing with every passing day and the enormous usage of electricity is becoming a necessity. One of the techniques to enjoy the assistances in a smart home is the efficiency to manage the electric energy. When electric energy is managed in an appropriate way, it drastically saves sufficient power even to be spent during hard time as when hit by natural calamities. To accomplish this, prediction of energy consumption plays a very important role. This proposed prediction model Coherent Weighted K-Means Clustering ARIMA (CWKMCA) enhances the weighted k-means clustering technique by adding weights to the cluster points. Forecasting is done using the ARIMA model based on the centroid of the clusters produced. The dataset for this proposed work is taken from the Pecan Project in Texas, USA. The level of accuracy of this model is compared with the traditional ARIMA model and the Weighted K-Means Clustering ARIMA Model. When predicting,errors such as RMSE, MAPE, AIC and AICC are analysed, the results of this suggested work reveal lower values than the ARIMA and Weighted K-Means Clustering ARIMA models. This model also has a greater loglikelihood, demonstrating that this model outperforms the ARIMA model for time series forecasting.

• Journal of Power Electronics
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• 제14권1호
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• pp.175-182
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• 2014

Tracking harmonic current quickly and precisely is one of the keys to designing active power filters (APF). In the past, the current state feedback decoupling PI control was an effective means for three-phase systems in the current control of constant voltage constant frequency inverters and high frequency PWM reversible rectifiers. This paper analyzes in detail the limitation of the conventional PI conditioner in the APF application field and presents a novel PI control method. Canceling the delay of one sampling period and the misadjustment for tracking the harmonic current is the key problem of this PI control. In this PI control, the predictive output current value is obtained by a state observer. The delay of one sampling period is remedied in this digital control system by the state observer. The predictive harmonic command current value is obtained by a repetitive predictor synchronously. The repetitive predictor can achieve better predictions of the harmonic current. By this means, the misadjustment of the conventional PI control for tracking the harmonic current is cancelled. The experiment results with a three-level NPC APF indicate that the steady-state accuracy and dynamic response of this method are satisfying when the proposed control scheme is implemented.

• 한국정보통신학회논문지
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• 제25권4호
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• pp.603-610
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• 2021

본 논문에서는 사용자의 전력소비패턴을 추출하고 사용자의 환경 및 감성을 적용한 최적 소비패턴을 모델링한 후, 이 두 가지의 패턴을 비교 적용하여 사용자의 전력소비행위 변화를 통한 전력의 효율적 사용 방법을 제시한다. 유의미한 소비패턴을 추출하기 위하여 벡터 표준화 및 이진 데이터 변환방법을 사용하고, k-평균 군집화를 적용한 앙상블의 합집합에 대한 학습과 k값에 따른 지지도를 적용하였으며, 최적 전력소비패턴 모델은 상대적 평균 소비량이 적은 앙상블 합집합에 대한 학습 결과를 기준으로 강제 및 감성 제어를 적용하여 생성하였다. 실험을 통하여 전력소비행위 변화 유도대상 추출 시 클러스터의 수와 일치율 간의 상관관계를 파악함으로써, 사용자의 의도에 따라 강제 및 감성 기반의 제어가 가능하도록 클러스터의 수나 크기 조절을 통한 다양한 윈도우에 적용할 수 있음을 검증하였다.

• 문화기술의 융합
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• 제9권2호
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• pp.143-150
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• 2023

우리나라의 1인당 국민소득이 증가하면서 장애인의 삶의 질 향상을 위한 다양한 여가 활동에 참여가 장려되고있다. 그러나 여가활동 참여를 위해서는 여가가 행해지는 장소까지의 이동이 선행되어야 하므로, 장애인의 여가활동을 위한 이동수단에 대한 관심이 커지고 있다. 수동 및 전동 휠체어는 여가활동을 위한 이동수단으로서 각각의 단점을 가지고 있어서 수동 휠체어에 전동 휠체어의 기능을 접합하는 휠체어 동력보조 장치에 대한 관심이 높아지고있다. 본 연구에서는 휠체어 동력보조 장치 제품들의 FDA 승인 과정을 조사하고, 세계 각국에서 생산하는 측면부착형, 전방부착형, 하방부착형, 후방부착형 휠체어 동력보조 장치들의 특성을 파악하였다. 이러한 정보들은 국내 장애인 및 보조인들이 환자의 상태에 따라 최적의 제품을 선택하는데 큰 도움이 될 것이다. 장애인들이 자신에게 적합한 동력 보조 장치를 선택할 수 있도록 많은 사용적합성 시험과 임상사례 연구가 필요하다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.163-165
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• 2003

Over the past several years, the application extent of the real-time systems is being expanded with the progress of civilization. An effort to minimize power consumption at the system is being accomplished in several fields from the design of an analog/digital circuit up to the device level Things of this effort have included the power optimum-technique to minimize power consumption at the digital logic circuit and the dynamic managed skill by means o( the decision of the operating system. In this paper, we designed of low power system by using Power-optimized method. As an effective low-power design, we designed the low power system which it has a monitoring system within the main board and a personal computer.

• Current Photovoltaic Research
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• 제4권2호
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• pp.80-86
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• 2016

Since the last five years it has become a lot of solar power plants installed. However, by installing the large-scale solar power station it is not easy to predict the actual generation years. Because there are a variety of factors, such as changes daily solar radiation, temperature and humidity. If the power output can be measured accurately it predicts profits also we can measure efficiency for solar power plants precisely. Therefore, Prediction of power generation is forecast to be a useful research field. In this study, out discovering the factors that can improve the accuracy of the prediction of the photovoltaic power generation presents the means to apply them to the power generation amount prediction.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.1109-1111
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• 1997

The purpose of this paper is to analyze the effects of switching-over control for power system stabilization. Switching-over control is applied to western part of korea electric power system to improve transient stability and short-circuit capacity. It's effectiveness is demonstrated in terms of fault current level and critical clearing time which is quantitative evaluation means of transient stability. The effect of generator tripping for power system stabilization is also presented.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.813-825
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• 2014

To maximize electric power production using wave energy extractions from resonance power buoys, the maximum motion displacement spectra of the buoys can primarily be obtained under a given wave condition. In this study, wave spectra observed in shoaling water were formulated. Target resonance frequencies were established from the arithmetic means of modal frequency bands and the peak frequencies. The motion characteristics of the circular cylindrical power buoys with corresponding drafts were then calculated using numerical models without considering PTO damping force. Results showed that the heave motions of the power buoys in shoaling waters with insufficient drafts produced greater amplification effects than those in deep seas with sufficient drafts.