• 제목/요약/키워드: Sensitivity coefficient

검색결과 917건 처리시간 0.029초

시각장애 아동과 정상 아동의 선자세 균형 비교 (The Comparison Between Blind and Normal Children in Standing Position)

  • 김중선;이정순
    • The Journal of Korean Physical Therapy
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    • 제15권1호
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    • pp.119-154
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    • 2003
  • In this paper, the proprioceptive sensitivity was compared by Foot-Hand task method and the effect of the proprioceptive sensitivity and auditory to the standing position between blind and normal children was measured using BPM for 56 children in 7, 8, 9 and 10 years old. There are three measurement methods are used for BPM : Rest, Forward Looking, 'Sound' position. The following conclusions were obtained from the above measurements. 1. In comparison of proprioceptive sensitivity between blind and normal children, there is no significant difference(p > .05). There is no significant difference in comparison of each age group and also there is no difference in each gender group(p > .05). 2. In comparison of standing position measurement between blind and normal children, there is any difference (p > .05) in three measurement(Rest, Forward Looking, 'Sound' position) but there is no significant difference in each gender difference(p > .05). There is any difference between Rest and 'Sound' position of blind children, also there is any difference between Forward Looking and ' Sound ' position, rest and 'Sound' position of normal children(p > .05). 3. There is no significant difference of correlation between proprioceptive sensitivity test and standing position measurement in Pearson correlation coefficient(p > .05).

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Application of data driven modeling and sensitivity analysis of constitutive equations for improving nuclear power plant safety analysis code

  • ChoHwan Oh;Doh Hyeon Kim;Jeong Ik Lee
    • Nuclear Engineering and Technology
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    • 제55권1호
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    • pp.131-143
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    • 2023
  • Constitutive equations in a nuclear reactor safety analysis code are mostly empirical correlations developed from experiments, which always accompany uncertainties. The accuracy of the code can be improved by modifying the constitutive equations fitting wider range of data with less uncertainty. Thus, the sensitivity of the code with respect to the constitutive equations is evaluated quantitatively in the paper to understand the room for improvement of the code. A new methodology is proposed which first starts by dividing the thermal hydraulic conditions into multiple sub-regimes using self-organizing map (SOM) clustering method. The sensitivity analysis is then conducted by multiplying an arbitrary set of coefficients to the constitutive equations for each sub-divided thermal-hydraulic regime with SOM to observe how the code accuracy varies. The randomly chosen multiplier coefficient represents the uncertainty of the constitutive equations. Furthermore, the set with the smallest error with the selected experimental data can be obtained and can provide insight which direction should the constitutive equations be modified to improve the code accuracy. The newly proposed method is applied to a steady-state experiment and a transient experiment to illustrate how the method can provide insight to the code developer.

공연산업의 경제적 파급효과 분석 (Estimation of Economic Value of the Performance Industry)

  • 배기형
    • 한국콘텐츠학회논문지
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    • 제13권1호
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    • pp.147-155
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    • 2013
  • 본 연구의 목적은 공연산업의 경제적 파급 효과를 분석하는데 있다. 연구분석을 위해 한국은행의 2009년 산업연관표를 이용하여 연극, 음악 및 기타 예술(390 부문)만을 공연산업으로 한정하고 새로이 공연 산업연관표를 작성하여 공연산업의 경제적 파급효과를 분석하였다. 연구 결과, 공연산업의 총생산유발액은 391.6조원, 소득유발액은 65.1조원, 생산세유발액은 총 16.3조원으로 나타났다. 특히 공연산업의 생산유발계수는 1,387, 감응도 계수 0.020, 영향력계수 0.025, 부가가치유발계수 0.662, 소득유발계수 0.455, 생산세유발계수 0.046 그리고 노동유발계수 0.010 등으로 나타났다.

곡선부 통과 열차의 주행안전성 평가에 관한 연구 (A Study on the Assessment of Running Safety of Railway Vehicle passing through Curve)

  • 박광수;이희성
    • 한국철도학회논문집
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    • 제10권5호
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    • pp.492-498
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    • 2007
  • 곡선통과 새마을호 열차의 주행안전성을 평가하기 위하여 다물체동력학 해석모델이 사용된다. 이 모델과 ADAMS/Rail 사용하여 탈선계수와 관련된 변수의 변화에 따른 민감도해석이 수행된다. 저속에서 우측차륜의 탈선계수와 윤중감소율이 좌측차륜보다 높으나, 고속의 경우는 좌측차륜이 우측차륜보다 높다. 곡선반경의 감소에 따라 탈선계수와 윤중감소율이 감소된다. 완화곡선의 길이가 증가하면 탈선계수는 증가하나 윤중감소율은 변화가 없다. 캔트가 증가하면 탈선계수와 윤중감소율이 증가한다.

Comparison of machine learning algorithms to evaluate strength of concrete with marble powder

  • Sharma, Nitisha;Upadhya, Ankita;Thakur, Mohindra S.;Sihag, Parveen
    • Advances in materials Research
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    • 제11권1호
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    • pp.75-90
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    • 2022
  • In this paper, functionality of soft computing algorithms such as Group method of data handling (GMDH), Random forest (RF), Random tree (RT), Linear regression (LR), M5P, and artificial neural network (ANN) have been looked out to predict the compressive strength of concrete mixed with marble powder. Assessment of result suggests that, the overall performance of ANN based model gives preferable results over the different applied algorithms for the estimate of compressive strength of concrete. The results of coefficient of correlation were maximum in ANN model (0.9139) accompanied through RT with coefficient of correlation (CC) value 0.8241 and minimum root mean square error (RMSE) value of ANN (4.5611) followed by RT with RMSE (5.4246). Similarly, other evaluating parameters like, Willmott's index and Nash-sutcliffe coefficient value of ANN was 0.9458 and 0.7502 followed by RT model (0.8763 and 0.6628). The end result showed that, for both subsets i.e., training and testing subset, ANN has the potential to estimate the compressive strength of concrete. Also, the results of sensitivity suggest that the water-cement ratio has a massive impact in estimating the compressive strength of concrete with marble powder with ANN based model in evaluation with the different parameters for this data set.

국내 연약지반의 강성지수(Ir)에 관한 연구 (The Study on Rigidity Index of the Soft Clay in Korea)

  • 서수봉;윤일형;이재식;구남실
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 가을 학술발표회 논문집
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    • pp.49-54
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    • 2000
  • Several soil parameters can be calculated for results of Piezocone test; sensitivity, soil classification, OCR, undrained shear strength, coefficient of consolidation etc., and used to analysis geotechnical problems. Particularly, the coefficient of consolidation which is related to degree of consolidation varies according to rigidity index(I/sub r/). In this study, rigidity index(I/sub r/) was analyzed by Roy's formula. Trixial tests and unconfined compression tests data in the ten sites was analyzed. In conclusion, rigidity index(I/sub r/) was suggested such as rigidity index(I/sub r/) = 15∼60, average rigidity index value(I/sub r/) of approximately 33 within a country.

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곡선부 선로 조건에 따른 차량의 탈선안전도평가 (An Assessment of Derailment Safety of Railway Vehicle depending on Curve Rail Condition)

  • 유희상;박광수;이희성
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.953-958
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    • 2007
  • To assess the derailment safety of the Samaeul Train, We developed a fleet analysis model and carried out sensitivity analysis of the variables related to derailment factors with ADAMS/Rail computing analysis method. Depending on the variation of the running speed in curve section, derailment coefficient and wheel load reduction rate are high at right side wheels in slow running speed section and low at left side wheel in high running speed. According to decreasing the radius of curve, derailment coefficient and wheel load decreasing rate are increased. Derailment coefficient is proportional to transition curve length and wheel load decreasing rate is constant. Cant value rising causes wheel load deduction rate rising.

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Transonic flow past a Whitcomb airfoil with a deflected aileron

  • Kuzmin, Alexander
    • International Journal of Aeronautical and Space Sciences
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    • 제14권3호
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    • pp.210-214
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    • 2013
  • The sensitivity of transonic flow past a Whitcomb airfoil to deflections of an aileron is studied at free-stream Mach numbers from 0.81 to 0.86 and vanishing or negative angles of attack. Solutions of the Reynolds-averaged Navier-Stokes equations are obtained with a finite-volume solver using the $k-{\omega}$ SST turbulence model. The numerical study demonstrates the existence of narrow bands of the Mach number and aileron deflection angles that admit abrupt changes of the lift coefficient at small perturbations. In addition, computations reveal free-stream conditions in which the lift coefficient is independent of aileron deflections of up to 5 degrees. The anomalous behavior of the lift is explained by interplay of local supersonic regions on the airfoil. Both stationary and impulse changes of the aileron position are considered.

곡선부 통과 열차의 주행안전성 평가에 관한 연구 (A Study on the Assessment of Running Safety of Railway Vehicle passing through Curve)

  • 엄범규;김종오;양경탁;이희성
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.849-854
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    • 2008
  • For the running safety assessment of Saemaul train passing through curves, an analysis model for multibody system has been developed. By using this model and ADAMS/Rail, sensitivity analyses depending on the variation of parameters related to the derailment coefficients have been conducted. According to the increase of running speed, the derailment coefficient and unload ratio were increased. At high speed, the derailment coefficient and unload ratio of left wheel showed higher than right wheel. If the cant increased, the derailment coefficient and unload ratio increased. but decreased based on the balance cant value by the curvature and running speed.

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곡선부 주행 차량의 마모특성에 관한 연구 (A Study on the Wear Characteristics of R/S Passing through Curves)

  • 엄범규;현석;양경탁;이희성
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.813-819
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    • 2008
  • For the wear characteristics assessment of Saemaul train passing through curves, an analysis model for multi-car system has been developed. By using this model and ADAMS/Rail, sensitivity analyses have been conducted for the wear characteristics by changing the related parameters. According to the increase of running speed, the wear number, the sliding mean and friction coefficient were increased. At high speed, the wear number, the sliding mean and friction coefficient of left wheel showed higher than right wheel. If the cant increased, the wear number the sliding mean and friction coefficient increased. but decreased based on the balance cant value by the curvature and running speed.

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