• Title/Summary/Keyword: prediction method

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Variation of Crop Coefficient With Respect to the Reference Crop Evapotranspiration Estimation Methods in Ponded Direct Seeding Paddy Rice (담수직파재배 논벼의 기준작물 잠재증발산량 산정방법별 작물계수의 변화)

  • 정상옥
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.39 no.4
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    • pp.114-121
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    • 1997
  • In order to provide basic information for the estimation of evapotranspiration in the ponded direct seeding paddy field, both field lysimeter experiment and model prediction were performed to estimate daily ET. Various methods were used to predict daily reference crop ET and crop coefficients. Measure4 mean daily ET during the 1995 growing season varied from 5.9 to 6.1 mm depending on the species, while it varied from 5.1 to 5.5 mm in 1996. Model predicted mean daily ET during the 1995 growing season varied from 3.9 to 4.9 mm depending on the prediction model, while it varied from 3.5 to 4.7 mm in 1996. The smaller ET values both measured and predicted in 1996 were caused by the low values of temperature, sunshine hours, and solar radiation. Crop coefficients varied from 1.20 to 1.50 in 1995 depending on the prediction model, while it varied from 1.10 to 1.47 in 1996. Comparison of the seven reference crop ET prediction methods used in this study shows that the Penman-Monteith method and the FAO-Radiation method gave the lowest ET while the corrected Penman method and the Hargreaves method gave the largest ET. Since crop coefficients vary to a large extent based on the prediction methods, reference crop ET prediction method should be carefully selected in irrigation planning.

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Temporal Prediction Structure and Motion Estimation Method based on the Characteristic of the Motion Vectors (시간적 예측 구조와 움직임 벡터의 특성을 이용한 움직임 추정 기법)

  • Yoon, Hyo Sun;Kim, Mi Young
    • Journal of Korea Multimedia Society
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    • v.18 no.10
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    • pp.1205-1215
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    • 2015
  • Efficient multi-view coding techniques are needed to reduce the complexity of multi-view video which increases in proportion to the number of cameras. To reduce the complexity and maintain image quality and bit-rates, an motion estimation method and temporal prediction structure are proposed in this paper. The proposed motion estimation method exploits the characteristic of motion vector distribution and the motion direction and motion size of the block to place search points and decide the search patten adaptively. And the proposed prediction structure divides every GOP to decide the maximum index of hierarchical B layer and the number of pictures of each B layer. Experiment results show that the complexity reduction of the proposed temporal prediction structure and motion estimation method over hierarchical B pictures prediction structure and TZ search method which are used in JMVC(Joint Multi-view Video Coding) reference model can be up to 45∼70% while maintaining similar video quality and bit rates.

NON-CAUSAL INTERPOLATIVE PREDICTION FOR B PICTURE ENCODING

  • Harabe, Tomoya;Kubota, Akira;Hatori, Yoshinoir
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.723-726
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    • 2009
  • This paper describes a non-causal interpolative prediction method for B-picture encoding. Interpolative prediction uses correlations between neighboring pixels, including non-causal pixels, for high prediction performance, in contrast to the conventional prediction, using only the causal pixels. For the interpolative prediction, the optimal quantizing scheme has been investigated for preventing conding error power from expanding in the decoding process. In this paper, we extend the optimal quantization sceme to inter-frame prediction in video coding. Unlike H.264 scheme, our method uses non-causal frames adjacent to the prediction frame.

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Maritime region segmentation and segment-based destination prediction methods for vessel path prediction (선박 이동 경로 예측을 위한 해상 영역 분할 및 영역 단위 목적지 예측 방법)

  • Kim, Jonghee;Jung, Chanho;Kang, Dokeun;Lee, Chang Jin
    • Journal of IKEEE
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    • v.24 no.2
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    • pp.661-664
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    • 2020
  • In this paper, we propose a maritime region segmentation method and a segment-based destination prediction method for vessel path prediction. In order to perform maritime segmentation, clustering on destination candidates generated from the past paths is conducted. Then the segment-based destination prediction is followed. For destination prediction, different prediction methods are applied according to whether the current region is linear or not. In the linear domain, the vessel is regarded to move constantly, and linear prediction is applied. In the nonlinear domain with an uncertainty, we assume that the vessel moves similarly to the most similar past path. Experimental results show that applying the linear prediction and the prediction method using a similar path differently depending on the linearity and the uncertainty of the path is better than applying one of them alone.

Transition Prediction of Flat-plate and Cone Boundary Layers in Supersonic Region Using $e^N$-Method ($e^N$-Method를 이용한 초음속 영역에서의 평판 및 원뿔형 경계층의 천이 예측)

  • Jang, Je-Sun;Park, Seung-O
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.235-238
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    • 2006
  • This paper is about the code that realizes the $e^N$-Method for boundary-layer transition prediction. The $e^N$-Method based on the linear stability theory is applied to predicting boundary-layer transition frequently. This paper deals with the construction of code, stability analysis and the calculation of N-factor. The results of transition prediction using the $e^N$-Method for flat plate/cone compressible boundary-layers are presented.

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Experimental Study on Long-Term Prediction of Rebar Price Using Deep Learning Recursive Prediction Meothod (딥러닝의 반복적 예측방법을 활용한 철근 가격 장기예측에 관한 실험적 연구)

  • Lee, Yong-Seong;Kim, Kyung-Hwan
    • Korean Journal of Construction Engineering and Management
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    • v.22 no.3
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    • pp.21-30
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    • 2021
  • This study proposes a 5-month rebar price prediction method using the recursive prediction method of deep learning. This approach predicts a long-term point in time by repeating the process of predicting all the characteristics of the input data and adding them to the original data and predicting the next point in time. The predicted average accuracy of the rebar prices for one to five months is approximately 97.24% in the manner presented in this study. Through the proposed method, it is expected that more accurate cost planning will be possible than the existing method by supplementing the systematicity of the price estimation method through human experience and judgment. In addition, it is expected that the method presented in this study can be utilized in studies that predict long-term prices using time series data including building materials other than rebar.

Prediction of Strain Responses from Displacement Response Measurements (변위응답의 측정으로부터 변형률응답의 예측)

  • 이건명;신봉인;이한희
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.1384-1387
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    • 2001
  • Presented is a method to predict strain responses from displacement measurements on a mechanical structure. The method consists of forming a transformation matrix, which is calculated from displacement and strain modal matrices. The modal matrices can be obtained by either finite element analysis or modal testing. One disadvantage of the method is that it requires displacements on all measuring points be measured simultaneously. The strain prediction method is applied to a simple simulated system.

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Assessment of genomic prediction accuracy using different selection and evaluation approaches in a simulated Korean beef cattle population

  • Nwogwugwu, Chiemela Peter;Kim, Yeongkuk;Choi, Hyunji;Lee, Jun Heon;Lee, Seung-Hwan
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.12
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    • pp.1912-1921
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    • 2020
  • Objective: This study assessed genomic prediction accuracies based on different selection methods, evaluation procedures, training population (TP) sizes, heritability (h2) levels, marker densities and pedigree error (PE) rates in a simulated Korean beef cattle population. Methods: A simulation was performed using two different selection methods, phenotypic and estimated breeding value (EBV), with an h2 of 0.1, 0.3, or 0.5 and marker densities of 10, 50, or 777K. A total of 275 males and 2,475 females were randomly selected from the last generation to simulate ten recent generations. The simulation of the PE dataset was modified using only the EBV method of selection with a marker density of 50K and a heritability of 0.3. The proportions of errors substituted were 10%, 20%, 30%, and 40%, respectively. Genetic evaluations were performed using genomic best linear unbiased prediction (GBLUP) and single-step GBLUP (ssGBLUP) with different weighted values. The accuracies of the predictions were determined. Results: Compared with phenotypic selection, the results revealed that the prediction accuracies obtained using GBLUP and ssGBLUP increased across heritability levels and TP sizes during EBV selection. However, an increase in the marker density did not yield higher accuracy in either method except when the h2 was 0.3 under the EBV selection method. Based on EBV selection with a heritability of 0.1 and a marker density of 10K, GBLUP and ssGBLUP_0.95 prediction accuracy was higher than that obtained by phenotypic selection. The prediction accuracies from ssGBLUP_0.95 outperformed those from the GBLUP method across all scenarios. When errors were introduced into the pedigree dataset, the prediction accuracies were only minimally influenced across all scenarios. Conclusion: Our study suggests that the use of ssGBLUP_0.95, EBV selection, and low marker density could help improve genetic gains in beef cattle.

Long-Term Prediction of Prestress in Concrete Bridge by Nonlinear Regression Analysis Method (비선형 회귀분석기법을 이용한 콘크리트 교량 프리스트레스의 장기 예측)

  • Yang, In-Hwan
    • Journal of the Korea Concrete Institute
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    • v.18 no.4 s.94
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    • pp.507-515
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    • 2006
  • The purpose of the paper is to propose a method to give a more accurate prediction of prestress changes in prestressed concrete(PSC) bridges. The statistical approach of the method is using the measurement data of the structural system to develop a nonlinear regression analysis. Long-term prediction of prestress is achieved using nonlinear regression analysis. The proposed method is applied to the prediction of prestress of an actual prestressed concrete box girder bridge. The present study represents that confidence interval of long-term prediction becomes progressively narrower with the increase of in-situ measurement data. Therefore, the numerical results prove that a more realistic long-term prediction of prestress changes in PSC structures can be achieved by employing the proposed method. The prediction results can be efficiently used to evaluate prestress during the service life of structure so that the remaining prestress exceeds the control criteria.

A New Vessel Path Prediction Method Based on Anticipation of Acceleration of Vessel (가속도 예측 기반 새로운 선박 이동 경로 예측 방법)

  • Kim, Jonghee;Jung, Chanho;Kang, Dokeun;Lee, Chang Jin
    • Journal of IKEEE
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    • v.24 no.4
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    • pp.1176-1179
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    • 2020
  • Vessel path prediction methods generally predict the latitude and longitude of a future location directly. However, in the case of direct prediction, errors could be large since the possible output range is too broad. In addition, error accumulation could occur since recurrent neural networks-based methods employ previous predicted data to forecast future data. In this paper, we propose a vessel path prediction method that does not directly predict the longitude and latitude. Instead, the proposed method predicts the acceleration of the vessel. Then the acceleration is employed to generate the velocity and direction, and the values decide the longitude and latitude of the future location. In the experiment, we show that the proposed method makes smaller errors than the direct prediction method, while both methods employ the same model.