• 한국태양에너지학회 논문집
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• 제39권3호
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• pp.59-66
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• 2019

New and renewable energy forecasts are key technology to reduce the annual operating cost of new and renewable facilities, and accuracy of forecasts is paramount. In this study, we intend to build a model for the prediction of short-term solar power generation for 1 hour to 3 hours. To this end, this study applied two time series technique, ARIMA model without considering seasonality and SARIMA model with considering seasonality, comparing which technique has better predictive accuracy. Comparing predicted errors by MAE measures of solar power generation for 1 hour to 3 hours at four locations, the solar power forecast model using ARIMA was better in terms of predictive accuracy than the solar power forecast model using SARIMA. On the other hand, a comparison of predicted error by RMSE measures resulted in a solar power forecast model using SARIMA being better in terms of predictive accuracy than a solar power forecast model using ARIMA.

• 한국산학기술학회논문지
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• 제22권2호
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• pp.714-720
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• 2021

머신 러닝 및 신호처리에 활용되고 있는 정보이론적 학습법(ITL, information theoretic learning)은 커널 사이즈(σ) 설정이 매우 민감한 어려움을 지닌다. ITL의 성능지표중 하나인 코렌트로피 함수를 최대화하는 성능지표에 대해, 기울기에 존재하는 1/σ2를 제거한 뒤 남은 커널 사이즈에 대해 적응적으로 조절하는 방법들이 연구되었다. 이 논문에서는, 1/σ2의 커널 사이즈가 실제 시스템의 민감성이나 불안정에 큰 역할을 하고 있으며 남은 부분에 존재하는 커널 사이즈에 대한 최적해는 오차의 절대값 근방에 수렴함에 따라 오히려 수렴 후 가중치 갱신을 멈추게 하는 부작용이 나타남을 밝혔다. 이에 적응적 커널 사이즈 조절 대신 적절한 상수를 선택하는 것이 보다 효과적이라는 것을 제안하였고, 실험결과에서 동일한 수렴 속도에 약 2dB 향상된 정상상태 MSE를 보였다. 제안한 방식을 더욱 열악한 다경로 채널환경에 적용하여 실험한 결과 4dB 이상의 성능향상을 보여 제안한 방식은 열악한 상황일수록 더욱 향상된 성능을 보임을 알 수 있다.

• 농업과학연구
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• 제48권4호
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• pp.891-897
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• 2021

There is a need for a technology that can quickly and accurately analyze soil carbon contents. Existing soil carbon analysis methods are cumbersome in terms of professional manpower requirements, time, and cost. It is against this background that the present study leverages the soil physical properties of color and water content levels to develop a model capable of predicting the carbon content of soil sample. To predict the total carbon content of soil, the RGB values, water content of the soil, and lux levels were analyzed and used as statistical data. However, when R, G, and B with high correlations were all included in a multiple regression analysis as independent variables, a high level of multicollinearity was noted and G was thus excluded from the model. The estimates showed that the estimation coefficients for all independent variables were statistically significant at a significance level of 1%. The elastic values of R and B for the soil carbon content, which are of major interest in this study, were -2.90 and 1.47, respectively, showing that a 1% increase in the R value was correlated with a 2.90% decrease in the carbon content, whereas a 1% increase in the B value tallied with a 1.47% increase in the carbon content. Coefficient of determination (R²), root mean square error (RMSE), and mean absolute percentage error (MAPE) methods were used for regression verification, and calibration samples showed higher accuracy than the validation samples in terms of R² and MAPE.

• 의정연구
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• 제25권3호
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• pp.5-31
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• 2019

선거제도 변경 추진 과정에서 대표, 다수, 소수, 비례, 등가 등 여러 개념이 정확하게 사용되지 않아 선거제도에 관한 보편적 판단이 잘 이뤄지지 못하고 있다. 이 글은 선거제도 관련 개념 및 용어의 현황을 지적하여 올바른 규범적 논의가 가능하게 하는 기초 연구이다. 먼저, 다수대표제와 소수대표제, 소선거구와 중·대선거구, 절대다수제와 상대다수제, 다수대표제와 비례대표제 등 선거제도 명칭의 오용을 지적하고 보완한다. 다음으로, 대표성, 등가성, 비례성, 게리맨더링, 민주성, 직접선거, 평등선거 등의 원리와 이에 관련된 헌법재판소 결정을 분석한다. 현행 국회의원선거 1인2표제에서는 의원 간 득표 등가성과 정당 간 비례성이 낮으며, 오히려 1인1표제로 환원하되 지역구 및 비례대표를 포함한 전체 의석비가 정당 득표율에 비례하도록 비례대표의석을 배분하는 방식이 유권자의 선거방식 이해도와 정당 간의 비례성을 동시에 높일 수 있다. 끝으로, 국회의원을 비례대표제로 선출하기만 하면 비례대표성이 보장되는 것이 아니라는 맥락에서, 국회의원선거의 비례대표제와 다른 정치제도 간의 정합성을 논의한다.

• 대한암한의학회지
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• 제16권2호
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• pp.9-17
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• 2011

Objectives : Contradictions for Oncology acupuncture were searched and reviewed to establish fundamentals for the appropriate contraindication guideline. Methods : In order to search contraindications for oncology acupuncture, domestic journals, books and online database of Pubmed were searched using the terms, cancer, tumor, acupuncture, safety, contraindications and guideline were below. Results : We found 7 papers and 1 book by the above methods. We reviewed and suggested the contraindications. Contraindications for oncology acupuncture are neutropenia (absolute neutrophil count : ANC less than $500/mm^3$), thrombocytopenia (platelets less than $50,000/mm^3$), anticoagulant use, spinal instability, tumour nodule, lymphedema, prosthesis, intracranial deficits, confused patients, significant arrhythmia, patient refusal to treatment, severe neurotic patients and intracardiac defribillator. Contraindications for using semi-permanent needles are neutropenia (ANC less than $500/mm^3$), splenectomy, valvular heart disease, B, C hepatitis and keloids. Conclusions : Acupuncture for cancer patients pose significant risks but these guidelines are proposed in the hopes of providing certain boundaries in practicing oncology acupuncture. A more systematic and rigorous research is needed to establish a more reliable oncology acupuncture guidelines.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.30-33
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• 2002

To obtain good performance of radial basis function (RBF) neural networks, it needs very careful consideration in design. The selection of several parameters such as the number of centers and widths of the radial basis functions must be considered carefully since they critically affect the network's performance. We propose a learning algorithm for growing of complexity of RBF neural networks which is adapted automatically according to the complexity of tasks. The algorithm generates a new basis function based on the errors of network, the percentage of decreasing rate of errors and the nearest distance from input data to the center of hidden unit. The RBF's center is located at the point where the maximum of absolute interference error occurs in the input space. The width is calculated based on the standard deviation of distance between the center and inputs data. The steepest descent method is also applied for adjusting the weights, centers, and widths. To demonstrate the performance of the proposed algorithm, general problem of function estimation is evaluated. The results obtained from the simulation show that the proposed algorithm for RBF neural networks yields good performance in terms of convergence and accuracy compared with those obtained by conventional multilayer feedforward networks.

• 정보과학회 논문지
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• 제43권5호
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• pp.509-515
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• 2016

순위패턴매칭문제는 텍스트 T와 패턴 P가 주어질 때, P와 각 문자들의 순위가 동일한 순서로 나타나는 T의 모든 부분문자열을 찾는 문제이다. 순위패턴매칭문제는 주가지수분석과 음악의 유사성분석과 같이 문자 자체를 비교하는 것보다 값의 변화순서가 중요한 분야에서 연구가 진행되었다. 순위다중패턴매칭문제는 텍스트 T와 여러 개의 패턴들로 이루어진 패턴집합 $\mathbb{P}$가 주어질 때, $\mathbb{P}$에 속한 패턴과 각 문자들의 순위가 동일한 순서로 나타나는 T의 모든 부분문자열을 찾는 문제이다. 본 논문에서는 순위다중패턴매칭문제를 해결하는 해싱기반 알고리즘을 제시한다.

• Genomics & Informatics
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• 제14권4호
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• pp.187-195
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• 2016

In genetic association studies with high-dimensional genomic data, multiple group testing procedures are often required in order to identify disease/trait-related genes or genetic regions, where multiple genetic sites or variants are located within the same gene or genetic region. However, statistical testing procedures based on an individual test suffer from multiple testing issues such as the control of family-wise error rate and dependent tests. Moreover, detecting only a few of genes associated with a phenotype outcome among tens of thousands of genes is of main interest in genetic association studies. In this reason regularization procedures, where a phenotype outcome regresses on all genomic markers and then regression coefficients are estimated based on a penalized likelihood, have been considered as a good alternative approach to analysis of high-dimensional genomic data. But, selection performance of regularization procedures has been rarely compared with that of statistical group testing procedures. In this article, we performed extensive simulation studies where commonly used group testing procedures such as principal component analysis, Hotelling's $T^2$ test, and permutation test are compared with group lasso (least absolute selection and shrinkage operator) in terms of true positive selection. Also, we applied all methods considered in simulation studies to identify genes associated with ovarian cancer from over 20,000 genetic sites generated from Illumina Infinium HumanMethylation27K Beadchip. We found a big discrepancy of selected genes between multiple group testing procedures and group lasso.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.893-897
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• 2006

Structures with additional frictional damping system have strong nonlinearity that the dynamic behavior is highly affected. by the relative magnitude between frictional force and excitation load. In this study, normalized response spectra of the structures with non-dimensional friction force are obtained through nonlinear time history analyses of the mass-normalized single degree of freedom systems using 20 ground motion data recorded on rock site. The variation of the control performance of frictional damping system is investigated in terms of the dynamic load and the structural natural period, of which effects were not considered in the previous studies. Least square curve fitting equations are presented for describing those normalized response spectrum and optimal non-dimensional friction forces are obtained for controlling the peak displacement and absolute acceleration of the structure based on the derivative of the curve fitted design spectrum.

• 한국콘텐츠학회논문지
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• 제17권10호
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• pp.334-342
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• 2017

정보통신기술의 발달로 방송중계 방식은 급격히 변화하고 있다. 무선통신망중계방송(DMNG) 방식의 도입은 일인중계를 가능케 함으로써 장비와 인력 측면에서 절대적인 감축 효과를 낳았다. 하지만 방송안정성과 화질과 같은 방송의 기본적인 부분에 대한 완성도는 떨어지고 있는 것이 현실이다. 이에 본 논문은 '백팩'이라고 불리는 무선이동통신중계 장비와 방송 시스템에 대해 분석하고 향후 발전 방안에 대해 논의한다. 이를 위해 백팩 중계방송의 성공과 실패 사례를 분석함으로 현장중계 개선에 대한 구체적 방안을 제시한다. 현장을 신속하게 중계하는 방식의 방송은 향후 지속적으로 증가할 것이다. 본 논문은 가까운 미래에 기술적으로 무선통신이 발전하고 이에 대한 방송의 활용이 더욱 중요해지는 시점에서 무선이동통신을 활용한 중계방송에 대한 연구로 가치를 가진다.