• 제목/요약/키워드: Accuracy analysis

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부실기업예측모형의 판별력 비교 (A Comparison of the Discrimination of Business Failure Prediction Models)

  • 최태성;김형기;김성호
    • 한국경영과학회지
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    • 제27권2호
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    • pp.1-13
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    • 2002
  • In this paper, we compares the business failure prediction accuracy among Linear Programming Discriminant Analysis(LPDA) model, Multivariate Discriminant Analysis (MDA) model and logit analysis model. The Data for 417 companies analyzed were gathered from KIS-FAS Published by Korea Information Service in 1999. The result of comparison for four time horizons shows that LPDA Is advantageous in prediction accuracy over the other two models when over all tilt ratio and business failure accuracy are considered simultaneously.

양면지지형 유정압테이블 운동정밀도의 유한요소 해석 (Finite Element Analysis on the Motion Accuracy of Double-sides Hydrostatic Table)

  • 박천홍;정재훈;이후상;이찬홍
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 추계학술대회 논문집
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    • pp.188-192
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    • 2000
  • An analysjs model for calculation the motion accuarcy of double sides hydrostatic table is proposed in thn paper. For the analysis of motion accuracy, profiles of each rails are assumed as periodic function, and represented using Fourier coefficients. Variahon of bearing clearance is represented as the vanation of linear, angular displacement of table and profiles of rails. Motion accuracy is calculated in the basis of finite element analysis on the pressure dutributmn of table. In order to improve calculating time in the analysis of motion accuracy, The proposed modeling method converts double sides table to single side table equivalently Results by the proposed method 1s compared with directly caculated results mdyhcally, and also compared wlth experimental results. From the theoretical and experimental analysis, it is confirmed that the proposed modeling mothod is very effective to analyze the motion accuracy of dauble sides hydrostatic table.

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Accuracy analysis of flood forecasting of a coupled hydrological and NWP (Numerical Weather Prediction) model

  • Nguyen, Hoang Minh;Bae, Deg-Hyo
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2017년도 학술발표회
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    • pp.194-194
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    • 2017
  • Flooding is one of the most serious and frequently occurred natural disaster at many regions around the world. Especially, under the climate change impact, it is more and more increasingly trend. To reduce the flood damage, flood forecast and its accuracy analysis are required. This study is conducted to analyze the accuracy of the real-time flood forecasting of a coupled meteo-hydrological model for the Han River basin, South Korea. The LDAPS (Local Data Assimilation and Prediction System) products with the spatial resolution of 1.5km and lead time of 36 hours are extracted and used as inputs for the SURR (Sejong University Rainfall-Runoff) model. Three statistical criteria consisting of CC (Corelation Coefficient), RMSE (Root Mean Square Error) and ME (Model Efficiency) are used to evaluate the performance of this couple. The results are expected that the accuracy of the flood forecasting reduces following the increase of lead time corresponding to the accuracy reduction of LDAPS rainfall. Further study is planed to improve the accuracy of the real-time flood forecasting.

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공대지 무장투하정확도 해석에 대한 연구 (A Study on the Accuracy Analysis for Air-to-Ground Weapon Delivery)

  • 조한상;송재일;이상철
    • 한국항공우주학회지
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    • 제35권8호
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    • pp.741-746
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    • 2007
  • 본 논문에서는 공대지 무장의 무장투하정확도에 대한 해석기법을 제시하였다. 항공기의 전투효과도(Combat Effectiveness)를 평가하는데 있어 중요한 요인인 공격능력(Lethality)은 공대지 무장투하정확도 개선능력에 좌우된다. 항공기 초기 설계단계부터 최종 검증단계 까지 무장투하정확도에 영향을 미치는 요소들을 기술하였으며 각 요소들을 무장투하정확도에 반영하는 기법과 정량적으로 평가하는 방안을 제시하였다. 무장투하정확도 분석은 Bias error를 영으로 가정하고 Random error에 의한 투하오차만을 분석 대상으로 하였다.

밀리부품의 정밀도 향상을 위한 다단계 성형 및 금형 해석 (Multi-Stage Forming Analysis of a Milli-Component for Improvement of Forming Accuracy)

  • 윤종헌;허훈;김승수;나경환;박훈재;최태훈
    • 소성∙가공
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    • 제13권5호
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    • pp.429-434
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    • 2004
  • Manufacturing process for milli components has recently gained researcher's focus with the increasing tendency toward highly integrated and micro-scaled parts for electronic devices. The milli-components need more precise manufacturing process than the conventional manufacturing process since the parts require higher dimensional accuracy than the conventional ones. In order to enhance the forming accuracy and productivity, various forming procedures proposed and studied by many researchers. In this paper, forming analysis of milli-components has been studied with a new micro-former. In modeling of progressive dies, multi-stage forming sequence has been analyzed with finite element analysis by LS-DYNA3D. The analysis proposes the sequential die and part shapes with the corresponding punch force and dimensional accuracy. The analysis also considers the effect of elastic dies on the dimensional accuracy of the formed parts. The analysis result demonstrates that the elastic analysis in the milli-forming process is indispensable for accurate forming analysis. The analysis procedure in the paper will provide good information in design of a new micro-former and milli-component

Accuracy Analysis of Optimal Trajectory Planning Methods Based on Function Approximation for a Four-DOF Biped Walking Model

  • Peng Chunye;ONO Kyosuke
    • Journal of Mechanical Science and Technology
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    • 제19권spc1호
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    • pp.452-460
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    • 2005
  • Based on an introduced optimal trajectory planning method, this paper mainly deals with the accuracy analysis during the function approximation process of the optimal trajectory planning method. The basis functions are composed of Hermit polynomials and Fourier series to improve the approximation accuracy. Since the approximation accuracy is affected by the given orders of each basis function, the accuracy of the optimal solution is examined by changing the combinations of the orders of Hermit polynomials and Fourier series as the approximation basis functions. As a result, it is found that the proper approximation basis functions are the $5^{th}$ order Hermit polynomials and the $7^{th}-10^{th}$ order of Fourier series.

Alternative accuracy for multiple ROC analysis

  • Hong, Chong Sun;Wu, Zhi Qiang
    • Journal of the Korean Data and Information Science Society
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    • 제25권6호
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    • pp.1521-1530
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    • 2014
  • The ROC analysis is considered for multiple class diagnosis. There exist many criteria to find optimal thresholds and measure the accuracy of diagnostic tests for k dimensional ROC analysis. In this paper, we proposed a diagnostic accuracy measure called the correct classification simple rate, which is defined as the summation of true rates for each classification distribution and expressed as a function of summation of sequential true rates for two consecutive distributions. This measure does not weight accuracy across categories by the category prevalence and is comparable across populations for multiple class diagnosis. It is found that this accuracy measure does not only have a relationship with Kolmogorov - Smirnov statistics, but also can be represented as a linear function of some optimal threshold criteria. With these facts, the suggested measure could be applied to test for comparing multiple distributions.

다중비교를 이용한 샘플수와 샘플링 시점수의 원샷 시스템 신뢰도 추정방법 정확성에 대한 영향 분석 (Effect Analysis of Sample Size and Sampling Periods on Accuracy of Reliability Estimation Methods for One-shot Systems using Multiple Comparisons)

  • 손영갑
    • 한국군사과학기술학회지
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    • 제15권4호
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    • pp.435-441
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    • 2012
  • This paper provides simulation-based results of effect analysis of sample size and sampling periods on accuracy of reliability estimation methods using multiple comparisons with analysis of variance. Sum of squared errors in estimated reliability measures were evaluated through applying seven estimation methods for one-shot systems to simulated quantal-response data. Analysis of variance was implemented to investigate change in these errors according to variations of sample size and sampling periods for each estimation method, and then the effect analysis on accuracy in reliability estimation was performed using multiple comparisons based on sample size and sampling periods. An efficient way to allocate both sample size and sampling periods for reliability estimation tests of one-shot systems is proposed in this paper from the effect analysis results.

금형변형을 고려한 성형 CAE에서의 스프링백 예측정확도 향상 (Improvement in Prediction Accuracy of Springback for Stamping CAE considering Tool Deformation)

  • 박정수;최현준;김세호
    • 소성∙가공
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    • 제23권6호
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    • pp.380-385
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    • 2014
  • An analysis procedure is proposed to improve the prediction accuracy of springback as well as to evaluate the structural stability of the tooling used for fabricating a side sill part from UHSS. The analysis couples the stamping analysis and the subsequent analysis of the tool structural. The deformation and stress results for the tool structure are obtained from the proposed analysis procedure. The results show that the amount of deformation and stresses are so high that the tool structure must be reinforced and the tooling design must consider structural stability. Springback is predicted with CAE in order to compare the prediction accuracy between the given tool geometry and the geometry from the structural analysis. The simulation results with the deformed tool can predict the experimental springback tendency accurately.

온라인 진단시스템에 사용되는 의사용 체질진단함수의 진단정확률 연구 (A Study on the Diagnostic Accuracy Rate of the Sasang Constitution Questionnaire for Doctors Used in the On-line System)

  • 전수형;정성일;권석동;박세정;김규곤;김종원
    • 사상체질의학회지
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    • 제20권3호
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    • pp.82-93
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    • 2008
  • 1. Objective The purpose of this study was to develop and upgrade the On-line SSCQ (Sasang Constitution Questionnaire) by making an analysis of diagnostic accuracy rate of Sasang Constitution Questionnaire for doctors. 2. Methods We have collected SSCQ-D(Sasang Constitution Questionnaire for Doctors) from the dept. of Sasang constitutional medicine in the four other university. We classified data according to Sasang constitution, sex, age and BMI and made an analysis using the chiefly discriminant analysis model, additionally frequency analysis, and Cronbach's alpha coefficient. 3. Results and Conclusion 1) Diagnostic accuracy rate of the SSCQ-D was between 71.33 and 95.14%. (1) About the whole subject the accuracy rate was 71.33%. (2) About the whole female the accuracy rate was 73.26%. (3) About the whole male the accuracy rate was 81.41%. 2) The more classification variables we used in this analysis study, the higher the diagnostic accuracy rate increased.

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