• 제목/요약/키워드: data weighting

검색결과 644건 처리시간 0.03초

데이터 가중 성능을 갖는 GMDH 알고리즘 및 전력 수요 예측에의 응용 (GMDH Algorithm with Data Weighting Performance and Its Application to Power Demand Forecasting)

  • 신재호;홍연찬
    • 제어로봇시스템학회논문지
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    • 제12권7호
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    • pp.631-636
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    • 2006
  • In this paper, an algorithm of time series function forecasting using GMDH(group method of data handling) algorithm that gives more weight to the recent data is proposed. Traditional methods of GMDH forecasting gives same weights to the old and recent data, but by the point of view that the recent data is more important than the old data to forecast the future, an algorithm that makes the recent data contribute more to training is proposed for more accurate forecasting. The average error rate of electric power demand forecasting by the traditional GMDH algorithm which does not use data weighting algorithm is 0.9862 %, but as the result of applying the data weighting GMDH algorithm proposed in this paper to electric power forecasting demand the average error rate by the algorithm which uses data weighting algorithm and chooses the best data weighting rate is 0.688 %. Accordingly in forecasting the electric power demand by GMDH the proposed method can acquire the reduced error rate of 30.2 % compared to the traditional method.

표준기상데이터 형식 분석 및 TRY 가중치 적용 (Analysis of the Typical Meteorological Data and the Weighting Factor of TRY)

  • 유호천;이관호;박소희;김경률
    • 한국태양에너지학회 논문집
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    • 제27권4호
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    • pp.157-165
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    • 2007
  • Typical meteorological data is fundamental to computer simulation introduced for environment-friendly architecture designs. Therefore, in order to improve accuracy of computer simulation, typical meteorological data should be established. By examining how to choose typical meteorological data, this study selected the optimized weight factor for TRY where weighting factor was not clearly set. As a result, the same weighting factor was applied to each climatic element and TRY data where the weight factor was applied could have the distribution very similar to measurement data. The weighting factor is considered to reflect geographical characteristics of Seoul and applied climatic elements.

표준기상데이터 작성 시 누락된 풍속 데이터의 보간 방법 제안 (A Proposal of an Interpolation Method of Missing Wind Velocity Data in Writing a Typical Weather Data)

  • 박소우;김주욱;송두삼
    • 한국태양에너지학회 논문집
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    • 제37권6호
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    • pp.79-91
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    • 2017
  • The meteorological data of 1 hour interval are required to write a typical weather data for building energy simulation. However, many meterological data are missing and the interpolation method to recover the missing data is required. Especially, lots of meterological data are replicated by linear interpolation method because the changes are not significant. While, the wind velocity fluctuates with the time or locations, so linear interpolation method is not appropriate in interpolation of the wind velocity data. In this study, three interpolation methods, using surrounding wind velocity data, Inverse Distance Weighting (IDW), Revised Inverse Distance Weighting (IDW-r), were analyzed considering the characteristics of wind velocity. The Revised Inverse Distance Weighting method, proposed in this study, showed the highest reliability in restoration of the wind velocity data among the analyzed methods.

Improved Collaborative Filtering Using Entropy Weighting

  • Kwon, Hyeong-Joon
    • International Journal of Advanced Culture Technology
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    • 제1권2호
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    • pp.1-6
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    • 2013
  • In this paper, we evaluate performance of existing similarity measurement metric and propose a novel method using user's preferences information entropy to reduce MAE in memory-based collaborative recommender systems. The proposed method applies a similarity of individual inclination to traditional similarity measurement methods. We experiment on various similarity metrics under different conditions, which include an amount of data and significance weighting from n/10 to n/60, to verify the proposed method. As a result, we confirm the proposed method is robust and efficient from the viewpoint of a sparse data set, applying existing various similarity measurement methods and Significance Weighting.

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자동 문서분류에서의 정규화 용어빈도 가중치방법 (Normalized Term Frequency Weighting Method in Automatic Text Categorization)

  • 김수진;박혁로
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
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    • pp.255-258
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    • 2003
  • This paper defines Normalized Term Frequency Weighting method for automatic text categorization by using Box-Cox, and then it applies automatic text categorization. Box-Cox transformation is statistical transformation method which makes normalized data. This paper applies that and suggests new term frequency weighting method. Because Normalized Term Frequency is different from every term compared by existing term frequency weighting method, it is general method more than fixed weighting method such as log or root. Normalized term frequency weighting method's reasonability has been proved though experiments, used 8000 newspapers divided in 4 groups, which resulted high categorization correctness in all cases.

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성공적인 ERP 시스템 구축 예측을 위한 사례기반추론 응용 : ERP 시스템을 구현한 중소기업을 중심으로 (An Application of Case-Based Reasoning in Forecasting a Successful Implementation of Enterprise Resource Planning Systems : Focus on Small and Medium sized Enterprises Implementing ERP)

  • 임세헌
    • Journal of Information Technology Applications and Management
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    • 제13권1호
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    • pp.77-94
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    • 2006
  • Case-based Reasoning (CBR) is widely used in business and industry prediction. It is suitable to solve complex and unstructured business problems. Recently, the prediction accuracy of CBR has been enhanced by not only various machine learning algorithms such as genetic algorithms, relative weighting of Artificial Neural Network (ANN) input variable but also data mining technique such as feature selection, feature weighting, feature transformation, and instance selection As a result, CBR is even more widely used today in business area. In this study, we investigated the usefulness of the CBR method in forecasting success in implementing ERP systems. We used a CBR method based on the feature weighting technique to compare the performance of three different models : MDA (Multiple Discriminant Analysis), GECBR (GEneral CBR), FWCBR (CBR with Feature Weighting supported by Analytic Hierarchy Process). The study suggests that the FWCBR approach is a promising method for forecasting of successful ERP implementation in Small and Medium sized Enterprises.

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매트릭스 팬슬 방법의 데이터 불균형 제거 기법 (Data De-weighting in Matrix Pencil Method)

  • 고진환;쉬샤오웬;류병주;이제훈;이정섭
    • 한국통신학회논문지
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    • 제36권8A호
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    • pp.741-747
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    • 2011
  • 잘 알려진 매트릭스 팬슬 방법은 정적이지 않은 환경 및 주파수가 같은 다중경로 신호가 존재 할때도 동작하는 입사각 추정방식이다. 매트릭스 팬슬방식은 기존의 공분산행렬을 사용한 방식보다 더 좋은 분해능을 보여 줄뿐 아니라 계산량의 측면에서도 매우 효과적이다. 본 논문에서는 매트릭스 팬슬 방식의 계산 과정에서 발생되는 데이터의 가중치가 균형이 맞지 않음으로써 생기는 영향에 관해 기술한다. 데이터의 균형이 맞는 새로운 방식의 매트릭스 팬슬 방식을 제안하고 데이터의 불균형을 해소할 수 있음을 보여주었다.

Design and Weighting Effects in Small Firm Server in Korea

  • Lee, Keejae;Lepkowski, James M.
    • Communications for Statistical Applications and Methods
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    • 제9권3호
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    • pp.775-786
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    • 2002
  • In this paper, we conducted an empirical study to investigate the design and weighting effects on descriptive and analytic statistics. The design and weighting effects were calculated for estimates produced from the 1998 small firm survey data. We considered the design and weighting effects on coefficients estimates of regression model using the design-based approach and the GEE approach.

나이브 베이시안 학습에서 정보이론 기반의 속성값 가중치 계산방법 (An Information-theoretic Approach for Value-Based Weighting in Naive Bayesian Learning)

  • 이창환
    • 한국정보과학회논문지:데이타베이스
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    • 제37권6호
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    • pp.285-291
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    • 2010
  • 본 연구에서는 나이브 베이시안 학습의 환경에서 속성의 가중치를 계산하는 새로운 방식을 제안한다. 기존 방법들이 속성에 가중치를 부여하는 방식인데 반하여 본 연구에서는 한걸음 더 나아가 속성의 값에 가중치를 부여하는 새로운 방식을 연구하였다. 이러한 속성값의 가중치를 계산하기 위하여 Kullback-Leibler 함수를 이용하여 가중치를 계산하는 방식을 제안하였고 이러한 가중치들의 특성을 분석하였다. 제안된 알고리즘은 다수의 데이터를 이용하여 속성 가중치 방식과 비교하였고 대부분의 경우에 더 좋은 성능을 제공함을 알 수 있었다.

자료 가중을 통한 전기비저항 탐사 자료의 역산 (Inversion of Resistivity Data using Data-weighting)

  • 조인기;이근수;김연정;윤대성
    • 지구물리와물리탐사
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    • 제18권1호
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    • pp.9-13
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    • 2015
  • 전기비저항 탐사 자료는 다양한 잡음을 포함하고 있다. 즉 전기비저항 자료는 높은 접촉저항, 장비의 측정 오차 및 주변의 불규칙한 전기적 잡음에 의해 영향을 받는다. 전기비저항 탐사 자료의 올바른 해석을 위해서는 이들 잡음의 정확한 추정이 요구된다. 이 연구에서는 상반성 시험을 통하여 추정된 잡음을 역산시 자료 가중에 반영하는 방법론을 제안하였다. 또한 역산시 현장 자료와 이론 자료 사이의 적합 오차와 상반성 오차를 분석하고, 상반성 오차와 적합 오차를 모두 이용하는 자료 가중법을 제안하였다. 현장 자료에 제안된 자료 가중법을 적용한 결과 통상적인 역산 결과에 비하여 국지적 이상대의 출현 빈도가 감소하는 것을 확인할 수 있었다.