• Title/Summary/Keyword: Change prediction

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Development of Assessment Model for the Optimal Site Prediction of Evergreen Broad-leaved Trees in Warm Temperate Zone according to Climate Change (기후변화에 따른 난대상록활엽수의 적지예측 평가 모델 개발)

  • Kang, Jin-Teak;Kim, Jeong-Woon;Kim, Cheol-Min
    • Journal of agriculture & life science
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    • v.46 no.3
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    • pp.47-58
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    • 2012
  • This study was carried out to develop assessment model for the optimal site prediction of Dendropanax morbifera, Evergreen broad-leaved trees in warm temperate zone according to climate change. It was created criterion for assessment model of the optimal site prediction by quantification method to possible analysis of quantitative and qualitative data, through study relationship between growth of tree and site environmental factors. A program of the optimal site prediction was developed using program version 3.2, an Avenue and Dialog Designer tool of ESRI as GIS(geographic information system) engine. Developed program applied to test accuracy of the optimal site prediction in study area of Wando, Jeollanam-do, having a various evergreen broad-leaved trees of warm temperate zone. In the results from analysis of the optimal site prediction on Dendropanax morbifera, the characteristics of optimal site were analyzed site environmental features with 401~500m of altitude, $15^{\circ}$ of slope, hillside of local topography, alluvium of deposit type, convex of slope type and south of aspect. The mapping area per grade of the optimal site prediction in the Dendropanax morbifera showed 1,487.2ha(25.4%) of class I, 1,020.3ha(17.4%) of class II, 2,231.8ha(38.2%) of class III and 1,110.5ha(19.0%) of class IV.

A Case Study of Aircraft Taxi Fuel Consumption Prediction Model (A380 Case) (항공기 지상 활주 연료소모량 예측모델 사례연구 (A380 중심))

  • Jang, Sungwoo;Lee, Youngjae;Yoo, Kwang Eui
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.28 no.2
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    • pp.29-35
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    • 2020
  • In this paper, we established a prediction model of fuel consumption at the aircraft's taxi operation. To look for countermeasures to reduce fuel consumption and carbon emissions, Airbus A380's actual ground taxi data was used. As a result, the number of stops or turnings during the taxi operation was not related to fuel consumption. It was confirmed that the amount of fuel consumption in the taxi operation was the taxi time and the thrust change. It can be confirmed that ground control optimization, which is the result of close cooperation between the control organization and the airline, is absolutely necessary to reduce taxi time and minimize the occurrence of thrust change events.

Prediction Methods for Scene Change in Motion Compensated Hybrid Coding (이동 보상형 복합 부호화기에서 Scene Change시의 예측 방법)

  • Kwon, Sang-Keun;Moon, Joo-Hee;Kim, Han-Soo;Kim, Jae-Kyoon
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1431-1433
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    • 1987
  • To transmit the image data at low rate, motion compensated(MC) hybrid coding scheme is used generally. In this scheme since coder performance could be decreased when scene change happens, another prediction method must be employed. In this paper we present two prediction methods. One is using the mean of neighboring block which was already transmitted. The others is estimating the current block with the neighboring blocks. When the proposed methods are applied to the conventional Me hybrid coding scheme, it is found that SNR gain of 7 dB is achieved and bit rate can be also reduced above 30%.

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Climate Prediction by a Hybrid Method with Emphasizing Future Precipitation Change of East Asia

  • Lim, Yae-Ji;Jo, Seong-Il;Lee, Jae-Yong;Oh, Hee-Seok;Kang, Hyun-Suk
    • The Korean Journal of Applied Statistics
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    • v.22 no.6
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    • pp.1143-1152
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    • 2009
  • A canonical correlation analysis(CCA)-based method is proposed for prediction of future climate change which combines information from ensembles of atmosphere-ocean general circulation models(AOGCMs) and observed climate values. This paper focuses on predictions of future climate on a regional scale which are of potential economic values. The proposed method is obtained by coupling the classical CCA with empirical orthogonal functions(EOF) for dimension reduction. Furthermore, we generate a distribution of climate responses, so that extreme events as well as a general feature such as long tails and unimodality can be revealed through the distribution. Results from real data examples demonstrate the promising empirical properties of the proposed approaches.

Using Evolutionary Optimization to Support Artificial Neural Networks for Time-Divided Forecasting: Application to Korea Stock Price Index

  • Oh, Kyong Joo
    • Communications for Statistical Applications and Methods
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    • v.10 no.1
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    • pp.153-166
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    • 2003
  • This study presents the time-divided forecasting model to integrate evolutionary optimization algorithm and change point detection based on artificial neural networks (ANN) for the prediction of (Korea) stock price index. The genetic algorithm(GA) is introduced as an evolutionary optimization method in this study. The basic concept of the proposed model is to obtain intervals divided by change points, to identify them as optimal or near-optimal change point groups, and to use them in the forecasting of the stock price index. The proposed model consists of three phases. The first phase detects successive change points. The second phase detects the change-point groups with the GA. Finally, the third phase forecasts the output with ANN using the GA. This study examines the predictability of the proposed model for the prediction of stock price index.

An Empirical Study on Aircraft Repair Parts Prediction Model Using Machine Learning (머신러닝을 이용한 항공기 수리부속 예측 모델의 실증적 연구)

  • Lee, Chang-Ho;Kim, Woong-Yi;Choi, Youn-Chul
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.26 no.4
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    • pp.101-109
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    • 2018
  • In order to predict the future needs of the aircraft repair parts, each military group develops and applies various techniques to their characteristics. However, the aircraft and the equipped weapon systems are becoming increasingly advanced, and there is a problem in improving the hit rate by applying the existing demand prediction technique due to the change of the aircraft condition according to the long term operation of the aircraft. In this study, we propose a new prediction model based on the conventional time-series analysis technique to improve the prediction accuracy of aircraft repair parts by using machine learning model. And we show the most effective predictive method by demonstrating the change of hit rate based on actual data.

Sensitivity of Typhoon Simulation to Physics Parameterizations in the Global Model (전구 모델의 물리과정에 따른 태풍 모의 민감도)

  • Kim, Ki-Byung;Lee, Eun-Hee;Seol, Kyung-Hee
    • Atmosphere
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    • v.27 no.1
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    • pp.17-28
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    • 2017
  • The sensitivity of the typhoon track and intensity simulation to physics schemes of the global model are examined for the typhoon Bolaven and Tembin cases by using the Global/Regional Integrated Model System-Global Model Program (GRIMs-GMP) with the physics package version 2.0 of the Korea Institute of Atmospheric Prediction Systems. Microphysics, Cloudiness, and Planetary boundary Layer (PBL) parameterizations are changed and the impact of each scheme change to typhoon simulation is compared with the control simulation and observation. It is found that change of microphysics scheme from WRF Single-Moment 5-class (WSM5) to 1-class (WSM1) affects to the typhoon simulation significantly, showing the intensified typhoon activity and increased precipitation amount, while the effect of the prognostic cloudiness and PBL enhanced mixing scheme is not noticeable. It appears that WSM1 simulates relatively unstable and drier atmospheric structure than WSM5, which is induced by the latent heat change and the associated radiative effect due to not considering ice cloud. And WSM1 results the enhanced typhoon intensity and heavy rainfall simulation. It suggests that the microphysics is important to improve the capability for typhoon simulation of a global model and to increase the predictability of medium range forecast.

Modification of Creep-Prediction Equation of Concrete utilizing Short-term Creep Test (단기 크리프 시험 결과를 이용한 콘크리트의 크리프 예측시의 수정)

  • 송영철;송하원;변근주
    • Journal of the Korea Concrete Institute
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    • v.12 no.4
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    • pp.69-78
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    • 2000
  • Creep of concrete is the most dominating factor affecting time-dependent deformations of concrete structures. Especially, creep deformation for design and construction in prestressed concrete structures should be predicted accurately because of its close relation with the loss in prestree of prestressed concrete structures. Existing creep-prediction models for special applications contain several impractical factors such as the lack ok accuracy, the requirement of long-term test and the lack of versatility for change in material properties, ets., which should be improved. In order to improve those drawbacks, a methodology to modify the creep-prediction equation specified in current Korean concrete structures design standard (KCI-99), which underestimates creep of concrete and does not consider change of condition in mixture design, is proposed. In this study, short-term creep tests were carried out for early-age concrete within 28 days after loading and their test results on influencing factors in the equation are analysed. Then, the prediction equation was modified by using the early-age creep test results. The modified prediction equation was verified by comparing their results with results obtained from long-term creep test.

The Study of Pressurant Inflow Prediction Using Temperature Change of Geostationary Satellite Propellant System (정지궤도 인공위성 추진시스템의 온도변화를 통한 배관내 가압제 유입 예측기법 연구)

  • Park Eung Sik;Jun Hyoung Yoll;Park Bong Kyu;Han Cho Young;Choi Seong Bong;Kim Yong Min
    • 한국전산유체공학회:학술대회논문집
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    • 2005.04a
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    • pp.96-99
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    • 2005
  • The geostationary satellite propulsion system has thermistors which can measure liquid propellant temperature at tanks, pipes and etc. In the satellite propulsion system with several tanks, the propellant in the tanks is moved by temperature change and this temperature pattern is constant. In this paper, the temperature change pattern of KOREASAT 1 propulsion system is compared and the prediction study of pressurant inflow using temperature change of geostationary satellite propulsion system is described.

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