• Title/Summary/Keyword: data value prediction

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Improving the Gravity Model for Feasibility Studies in the Cultural and Tourism Sector (문화·관광부문 타당성조사를 위한 중력모형의 개선방안)

  • Hae-Jin Lee
    • Asia-Pacific Journal of Business
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    • v.15 no.1
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    • pp.319-334
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    • 2024
  • Purpose - The purpose of this study is to examine the gravity model commonly used for demand forecasting upon the implementation of new tourist facilities and analyze the main causation of forecasting errors to provide a suggestion on how to improve. Design/methodology/approach - This study first measured the errors in predicted values derived from past feasibility study reports by examining the cases of five national science museums. Next, to improve the predictive accuracy of the gravity model, the study identified the five most likely issues contributing to errors, applied modified values, and recalculated. The potential for improvement was then evaluated through a comparison of forecasting errors. Findings - First, among the five science museums with very similar characteristics, there was no clear indication of a decrease in the number of visitors to existing facilities due to the introduction of new facilities. Second, representing the attractiveness of tourist facilities using the facility size ratio can lead to significant prediction errors. Third, the impact of distance on demand can vary depending on the characteristics of the facility and the conditions of the area where the facility is located. Fourth, if the distance value is below 1, it is necessary to limit the range of that value to avoid having an excessively small value. Fifth, depending on the type of population data used, prediction results may vary, so it is necessary to use population data suitable for each latent market instead of simply using overall population data. Finally, if a clear trend is anticipated in a certain type of tourist behavior, incorporating this trend into the predicted values could help reduce prediction errors. Research implications or Originality - This study identified the key factors causing prediction errors by using national science museums as cases and proposed directions for improvement. Additionally, suggestions were made to apply the model more flexibly to enhance predictive accuracy. Since reducing prediction errors contributes to increased reliability of analytical results, the findings of this study are expected to contribute to policy decisions handled with more accurate information when running feasibility analyses.

An Improved Load Operand Referencing Scheme Using A Hybrid Predictor (혼합 예측기를 사용하는 효율적인 적재 명령어의 오퍼랜드 참조 기법)

  • Choe, Seung-Gyo;Jo, Gyeong-San
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.7
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    • pp.2196-2203
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    • 2000
  • As processor's operational frequency increases and processors execute multiple instructions per cycle, the processor performance becomes more dependent on the load operand referencing latency and the data dependency. To reduce the operand fetch latency and to increase ILP by breaking the data dependency, we propose a value-address hybrid predictor using a reasonable size prediction buffer and analyse the performance improvement by the proposed predictor. Through the extensive simulation of 5 benchmark programs, the proposed hybrid prediction scheme accurately predicts 62.72% of all loads which are 12.64% higher than the value prediction scheme and show its cost-effectiveness compared to the address predition scheme. In addition, we analyse the performance improvement achieved by the stride management and the history of previous predictions.

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Life Prediction and Fatigue Strength Evaluation for Surface Corrosion Materials (인공부식재의 피로강도평가와 통계학적 수명예측에 관한 연구)

  • 권재도;진영준;장순식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.8
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    • pp.1503-1512
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    • 1992
  • The strength evaluation and life prediction on the corrosion part of structure is one of the most important subjects, as a viewpoint of reducing economic loss by regular inspection, maintenance, repair and replace. For this purpose, it has been difficult to obtain the available data on growth of pit depth or growth rate of each pit which depends on time. In this paper, the life prediction and strength evaluation method was suggested for the structure with irregular stress concentration part by surface corrosion. The statistical distribution pattern of corrosion depth and the degree of fatigue strength decline were confirmed according to corrosion period by artificial corrosion of SS41 steel. The life prediction and the fatigue strength evaluation of materials with consideration of the corrosion period on the extreme value statistic analysis by the data of maximum depth of corrosion and on random variable was studied.

Pixel-level prediction of velocity vectors on hull surface based on convolutional neural network (합성곱 신경망 기반 선체 표면 유동 속도의 픽셀 수준 예측)

  • Jeongbeom Seo;Dayeon Kim;Inwon Lee
    • Journal of the Korean Society of Visualization
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    • v.21 no.1
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    • pp.18-25
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    • 2023
  • In these days, high dimensional data prediction technology based on neural network shows compelling results in many different kind of field including engineering. Especially, a lot of variants of convolution neural network are widely utilized to develop pixel level prediction model for high dimensional data such as picture, or physical field value from the sensors. In this study, velocity vector field of ideal flow on ship surface is estimated on pixel level by Unet. First, potential flow analysis was conducted for the set of hull form data which are generated by hull form transformation method. Thereafter, four different neural network with a U-shape structure were conFig.d to train velocity vectors at the node position of pre-processed hull form data. As a result, for the test hull forms, it was confirmed that the network with short skip-connection gives the most accurate prediction results of streamlines and velocity magnitude. And the results also have a good agreement with potential flow analysis results. However, in some cases which don't have nothing in common with training data in terms of speed or shape, the network has relatively high error at the region of large curvature.

Effect of Heterogeneous Variance by Sex and Genotypes by Sex Interaction on EBVs of Postweaning Daily Gain of Angus Calves

  • Oikawa, T.;Hammond, K.;Tier, B.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.6
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    • pp.850-853
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    • 1999
  • Angus postweaning daily gain (PWDG) was analyzed to investigate effects of the heterogeneous variance and the genotypes by sex interaction on prediction of EBVs with data sets of various environmental levels. A whole data (16,239 records) was divided into six data sets according to averages of the best linear unbiased estimator (BLUE) of herd environment. The results comparing prediction models showed that single-trait model is adequate for most of the data sets except for the data set of poor environment for both of the bulls and the heifers where the heterogeneity of variance and the genotypes by sex interaction exists. In the prediction with the data set of the low environment level, the bull's EBVs by single-trait models had high product moment correlations with male EBVs of the bulls by the multitrait model. Whereas the heifer's EBVs had moderate correlations with female EBVs by the multitrait model. This moderate correlation seems to be resulted by the heterogeneity of variance and low heritability of the heifer's PWDG. The prediction models with heterogeneity of variance had little effect on the prediction of EBVs for the data sets with moderate to high genetic correlations.

On the Study of Perfect Coverage for Recommender System

  • Lee, Hee-Choon;Lee, Seok-Jun
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.4
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    • pp.1151-1160
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    • 2006
  • The similarity weight, the pearson's correlation coefficient, which is used in the recommender system has a weak point that it cannot predict all of the prediction value. The similarity weight, the vector similarity, has a weak point of the high MAE although the prediction coverage using the vector similarity is higher than that using the pearson's correlation coefficient. The purpose of this study is to suggest how to raise the prediction coverage. Also, the MAE using the suggested method in this study was compared both with the MAE using the pearson's correlation coefficient and with the MAE using the vector similarity, so was the prediction coverage. As a result, it was found that the low of the MAE in the case of using the suggested method was higher than that using the pearson's correlation coefficient. However, it was also shown that it was lower than that using the vector similarity. In terms of the prediction coverage, when the suggested method was compared with two similarity weights as I mentioned above, it was found that its prediction coverage was higher than that pearson's correlation coefficient as well as vector similarity.

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Development of ensemble machine learning model considering the characteristics of input variables and the interpretation of model performance using explainable artificial intelligence (수질자료의 특성을 고려한 앙상블 머신러닝 모형 구축 및 설명가능한 인공지능을 이용한 모형결과 해석에 대한 연구)

  • Park, Jungsu
    • Journal of Korean Society of Water and Wastewater
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    • v.36 no.4
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    • pp.239-248
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    • 2022
  • The prediction of algal bloom is an important field of study in algal bloom management, and chlorophyll-a concentration(Chl-a) is commonly used to represent the status of algal bloom. In, recent years advanced machine learning algorithms are increasingly used for the prediction of algal bloom. In this study, XGBoost(XGB), an ensemble machine learning algorithm, was used to develop a model to predict Chl-a in a reservoir. The daily observation of water quality data and climate data was used for the training and testing of the model. In the first step of the study, the input variables were clustered into two groups(low and high value groups) based on the observed value of water temperature(TEMP), total organic carbon concentration(TOC), total nitrogen concentration(TN) and total phosphorus concentration(TP). For each of the four water quality items, two XGB models were developed using only the data in each clustered group(Model 1). The results were compared to the prediction of an XGB model developed by using the entire data before clustering(Model 2). The model performance was evaluated using three indices including root mean squared error-observation standard deviation ratio(RSR). The model performance was improved using Model 1 for TEMP, TN, TP as the RSR of each model was 0.503, 0.477 and 0.493, respectively, while the RSR of Model 2 was 0.521. On the other hand, Model 2 shows better performance than Model 1 for TOC, where the RSR was 0.532. Explainable artificial intelligence(XAI) is an ongoing field of research in machine learning study. Shapley value analysis, a novel XAI algorithm, was also used for the quantitative interpretation of the XGB model performance developed in this study.

Prediction Technique of Energy Consumption based on Reinforcement Learning in Microgrids (마이크로그리드에서 강화학습 기반 에너지 사용량 예측 기법)

  • Sun, Young-Ghyu;Lee, Jiyoung;Kim, Soo-Hyun;Kim, Soohwan;Lee, Heung-Jae;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.21 no.3
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    • pp.175-181
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    • 2021
  • This paper analyzes the artificial intelligence-based approach for short-term energy consumption prediction. In this paper, we employ the reinforcement learning algorithms to improve the limitation of the supervised learning algorithms which usually utilize to the short-term energy consumption prediction technologies. The supervised learning algorithm-based approaches have high complexity because the approaches require contextual information as well as energy consumption data for sufficient performance. We propose a deep reinforcement learning algorithm based on multi-agent to predict energy consumption only with energy consumption data for improving the complexity of data and learning models. The proposed scheme is simulated using public energy consumption data and confirmed the performance. The proposed scheme can predict a similar value to the actual value except for the outlier data.

A Prediction of Turbulent Characteristics in a Complex Terrain by Linear Theory (선형이론에 의한 복잡지형 내 난류 특성의 예측)

  • Yoon, J.E.;Kyong, N.H.;Kim, S.W.
    • Journal of the Korean Solar Energy Society
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    • v.25 no.1
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    • pp.79-86
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    • 2005
  • The external conditions for estimating dynamic wind loads of wind turbines, such as the turbulence, the extreme wind, the mean velocity gradients and the flow angles, are simulated over GangWon Wind Energy Test Field placed in one of the most complex terrain in Korea. Reference meteorological data has been gathered at a height of 30m from 2003 to 2004 with a ultrasonic anemometer. The absolute value of the spectral energy are simulated and the verification of this prediction has been carried out with comparing to the experimental data. The most desirable place for constructing new wind turbine are resulted as Point 2 and Point 3 due to the lower value of Turbulence Intensity and the higher value of wind resource relatively.

A Selective Induction Framework for Improving Prediction in Financial Markets

  • Kim, Sung Kun
    • Journal of Information Technology Applications and Management
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    • v.22 no.3
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    • pp.1-18
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    • 2015
  • Financial markets are characterized by large numbers of complex and interacting factors which are ill-understood and frequently difficult to measure. Mathematical models developed in finance are precise formulations of theories of how these factors interact to produce the market value of financial asset. While these models are quite good at predicting these market values, because these forces and their interactions are not precisely understood, the model value nevertheless deviates to some extent from the observable market value. In this paper we propose a framework for augmenting the predictive capabilities of mathematical model with a learning component which is primed with an initial set of historical data and then adjusts its behavior after the event of prediction.