• 제목/요약/키워드: potential predictability

검색결과 60건 처리시간 0.026초

Evaluation of a Loss of Residual Heat Removal Event during Mid-Loop Operation

  • Seul, Kwang-Won;Bang, Young-Seok;Lee, Sukho;Kim, Hho-Jung
    • 한국원자력학회:학술대회논문집
    • /
    • 한국원자력학회 1996년도 춘계학술발표회논문집(2)
    • /
    • pp.23-28
    • /
    • 1996
  • The potential for the RELAP5/MOD3.2 was assessed for the loss-of-RHR event during the mid-loop operation and the predictability of major thermal-hydraulic phenomena was also evaluated for the long term transient. The analysis results of the typical two cases(cold leg opening case and pressurizer opening case) were compared with experimental data which was conducted at ROSA-IV/LSTF in Japan. As a result, it was shown that tile code was capable of simulating the thermal-hydraulic transport process with appropriate time step during the reduced inventory operation with the loss-of- RHR system.

  • PDF

제주 실시간 일사량의 기계학습 예측 기법 연구 (A Study on Prediction Techniques through Machine Learning of Real-time Solar Radiation in Jeju)

  • 이영미;배주현;박정근
    • 한국환경과학회지
    • /
    • 제26권4호
    • /
    • pp.521-527
    • /
    • 2017
  • Solar radiation forecasts are important for predicting the amount of ice on road and the potential solar energy. In an attempt to improve solar radiation predictability in Jeju, we conducted machine learning with various data mining techniques such as tree models, conditional inference tree, random forest, support vector machines and logistic regression. To validate machine learning models, the results from the simulation was compared with the solar radiation data observed over Jeju observation site. According to the model assesment, it can be seen that the solar radiation prediction using random forest is the most effective method. The error rate proposed by random forest data mining is 17%.

Predicting the Invasion Pathway of Balanus perforatus in Korean Seawaters

  • Choi, Keun-Hyung;Choi, Hyun-Woo;Kim, Il-Hoi;Hong, Jae-Sang
    • Ocean and Polar Research
    • /
    • 제35권1호
    • /
    • pp.63-68
    • /
    • 2013
  • The European Common Barnacle Balanus perforatus Brugiere (Crustacea, Cirripedia) has been introduced into the east coast of Korea, presumably via the ballast water of ships. The species has since been spreading along both the northern and southern coast to the east, most likely due to alongshore currents. We predicted the potential range expansion of Balanus perforatus in Korean waters using Genetic Algorithm for Rule-set Prediction (GARP), an environmental niche modeling technique. The results show that much of the southern coastal waters of Korea could be colonized by the spread of the nonindigenous species, but that the west coast is unlikely to be invaded. More sampling on the west coast would enhance the predictability of the model. To our knowledge, this is the first report of its kind for predicting marine nonindigenous species in Korean waters using GARP modeling.

Experimental studies on the fatigue life of shape memory alloy bars

  • Casciati, Sara;Marzi, Alessandro
    • Smart Structures and Systems
    • /
    • 제6권1호
    • /
    • pp.73-85
    • /
    • 2010
  • The potential offered by the thermo-mechanical properties of shape memory alloys (SMA) in structural engineering applications has been the topic of many research studies during the last two decades. The main issues concern the long-term predictability of the material behaviour and the fatigue lifetime of the macro structural elements (as different from the one of wire segments). The laboratory tests reported in this paper are carried out on bar specimens and they were planned in order to pursue two objectives. First, the creep phenomenon is investigated for two different alloys, a classical Ni-Ti alloy and a Cu-based alloy. The attention is then focused on the Cu-based alloy only and its fatigue characteristics at given temperatures are investigated. Stress and thermal cycles are alternated to detect any path dependency.

APPLICATIONS OF ELECTROPLATING METHOD FOR HEAT TRANSFER STUDIES USING ANALOGY CONCEPT

  • Ko, Sang-Hyuk;Moon, Deok-Won;Chung, Bum-Jin
    • Nuclear Engineering and Technology
    • /
    • 제38권3호
    • /
    • pp.251-258
    • /
    • 2006
  • This study presents an idea of using analogy concept to the heat transfer studies regarding the HTGR development. Theoretical backgrounds regarding the idea were reviewed. In order to investigate the predictability of a mass transfer system for heat transfer system phenomenology, an electroplating system coupled with a limiting current technique was adopted. Test facilities for laminar forced convection and natural convections under laminar and turbulent conditions were constructed, for which heat transfer correlations are known. The test results showed a close agreement between mass transfer and heat transfer systems, which is an encouraging indication of the validity of the analogy theory and the experimental methodology adopted. This paper shows the potential of the experimental method that validates the little-understood heat transfer phenomena, even in complex geometries such as HTGR.

High throughput approaches to predicting drug absorption potential using the immobilized artificial membrane phosphatidylcholine column and molar volume

  • Yoon, Chi-Ho;Shin, Beom-Soo;Chang, Hyun-Sook;Yoo, Sun-Dong
    • 대한약학회:학술대회논문집
    • /
    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
    • /
    • pp.239.2-239.2
    • /
    • 2003
  • The purpose of this study was to evaluate the predictability of the fraction of drug absorbed in humans using the immobilized artificial membrane phosphatidylcholine column (IAMPC) under optimized conditions in comparison with a conventional IAMPC method. Twenty commercial drugs, both acidic and basic in nature, were used in the study, Drugs were dissolved in acetonitrile:water (50:50, v/v) at a concentration of 100 mg/ml, and were injected on HPLC/UVD at a mobile phase (acetonitrile:DPBS = 10:90,v/v) with a flow rate of 0.5 ml/min equilibrated at 37$^{\circ}C$. (omitted)

  • PDF

GIS를 이용한 경기도 화남2지구의 지하수오염 예측에 관한 연구 (A Study on the Prediction of Groundwater Contamination using the GIS in Hwanam 2 Sector, Gyeonggi Province, Korea)

  • 손호웅
    • 공학논문집
    • /
    • 제5권1호
    • /
    • pp.89-107
    • /
    • 2004
  • 본 연구는 DRASTIC 모델에 구소선밀도, 토지이용 인자를 추가한 수정 DRASTIC 모델을 개발하여 경기도 화남2지구의 지하수오염 가능성을 예측하고자 하였다. 우리나라의 수리지질 환경에서 대수층은 대부분 암반 대수층인 점을 고려했을 때, 구조선밀도는 지하수 및 오염물질 유동에 직접적인 영향을 미치고, 토지이용은 점오염원 혹은 비점오염원의 영향을 간접적으로 반영할 수 있기 때문이다. 통계분석을 위하여 각 인자별 격자 레이어를 생성하고, 각각의 상관계수를 분석함으로써 신뢰도 여부를 판단하였다. 최종 결과물인 종합오염현황도는 수정 DRASTIC Potential과 여러 가지 오염원의 발생 부하량 값을 논리비교함으로써 수리지질학적인 측면에서의 오염가능성 지역과 수질측면에서의 오염가능성 지역을 예측할 수 있는 방안을 제시할 수 있었다.

  • PDF

GIS를 이용한 경기도 화남2지구의 지하수오염 예측에 관한 연구 (A STUDY ON THE PREDICTION OF GROUNDWATER CONTAMINATION USING THE GIS IN HWANAM 2 SECTOR, GYEONGGI PROVINCE, KOREA)

  • 손호웅
    • 지구물리
    • /
    • 제4권4호
    • /
    • pp.267-285
    • /
    • 2001
  • 본 연구는 DRASTIC 모델에 구조선밀도, 토지이용 인자를 추가한 수정 DRASTIC 모델을 개발하여 경기도 화남2지구의 지하수오염 가능성를 예측하고자 하였다. 우리나라의 수리지질 환경에서 대수층은 대부분 암반 대수층인 점을 고려했을 때, 구조선밀도는 지하수 및 오염물질 유동에 직접적인 영향을 미치고, 토지이용은 점오염원 혹은 비점오염원의 영향을 간접적으로 반영할 수 있기 때문이다. 통계분석을 위하여 각 인자별 격자 레이어를 생성하고, 각각의 상관계수를 분석함으로써 신뢰도 여부를 판단하였다. 최종 결과물인 종합오염현황도는 수정 DRASRIC Potential과 여러 가지 오염원의 발생 부하량 값을 논리비교함으로써 수리지질학적인 측면에서의 오염가능성 지역과 수질측면에서의 오염가능성 지역을 예측할 수있는 방안을 제시할 수 있었다.

  • PDF

Comparative Molecular Field Analysis of Dioxins and Dioxin-like Compounds

  • Ashek, Ali;Cho, Seung-Joo
    • Molecular & Cellular Toxicology
    • /
    • 제1권3호
    • /
    • pp.157-163
    • /
    • 2005
  • Because of their widespread occurrence and substantial biological activity, halogenated aromatic hydrocarbons are one of the important classes of contaminants in the environment. We have performed comparative molecular field analysis (CoMFA) on structurally diverse ligands of Ah (dioxin) receptor to explore the physico-chemical requirements for binding. All CoMFA models have given $q^{2}$ value of more than 0.5 and $r^{2}$ value of more than 0.83. The predictive ability of the models was validated by an external test set, which gave satisfactory predictive $r^{2}$ values. Best predictions were obtained with CoMFA model of combined modified training set ($q^{2}=0.631,\;r^{2}=0.900$), giving predictive residual value = 0.002 log unit for the test compound. We have suggested a model comprises of four structurally different compounds, which offers a good predictability for various ligands. Our QSAR model is consistent with all previously established QSAR models with less structurally diverse ligands. The implications of the CoMFA/QSAR model presented herein are explored with respect to quantitative hazard identification of potential toxicants.

Development of a Probability Prediction Model for Tropical Cyclone Genesis in the Northwestern Pacific using the Logistic Regression Method

  • Choi, Ki-Seon;Kang, Ki-Ryong;Kim, Do-Woo;Kim, Tae-Ryong
    • 한국지구과학회지
    • /
    • 제31권5호
    • /
    • pp.454-464
    • /
    • 2010
  • A probability prediction model for tropical cyclone (TC) genesis in the Northwestern Pacific area was developed using the logistic regression method. Total five predictors were used in this model: the lower-level relative vorticity, vertical wind shear, mid-level relative humidity, upper-level equivalent potential temperature, and sea surface temperature (SST). The values for four predictors except for SST were obtained from difference of spatial-averaged value between May and January, and the time average of Ni$\tilde{n}$o-3.4 index from February to April was used to see the SST effect. As a result of prediction for the TC genesis frequency from June to December during 1951 to 2007, the model was capable of predicting that 21 (22) years had higher (lower) frequency than the normal year. The analysis of real data indicated that the number of year with the higher (lower) frequency of TC genesis was 28 (29). The overall predictability was about 75%, and the model reliability was also verified statistically through the cross validation analysis method.