• 제목/요약/키워드: variance errors.

검색결과 236건 처리시간 0.028초

UTIS 구간통행속도 이상치 제거 알고리즘 (Error Filtering Algorithm for Accurate Travel Speed Measurement Using UTIS)

  • 기용걸;안계형;김은정;정준하;배광수;이철기
    • 한국ITS학회 논문지
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    • 제9권6호
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    • pp.33-42
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    • 2010
  • 구간통행속도는 도로의 교통상황을 나타내는 중요한 지표이며, UTIS(Urban Traffic Information System)는 도로의 구간 통행속도를 측정하여 제공하는 대표적인 구간속도 측정시스템이다. 시험운영 결과, 프로브 차량의 불규칙한 주행궤적, 무선통신 장치의 통신범위 등의 요인으로 UTIS 산출 속도의 신뢰도가 저하되는 현상이 일부 나타나고 있다. 본 논문에서는 이러한 오차를 줄이기 위해 UTIS에 포함된 이상치를 제거하는 알고리즘을 제안하였다. 제안된 알고리즘을 적용하여 현장실험을 실시한 결과 새로운 이상치 제거 알고리즘이 속도 측정값들 오차백분율의 분산을 기존 알고리즘보다 2배 이상 줄여주는 것으로 분석되었다. 이는 새로운 알고리즘이 이상치를 적절히 처리하여 구간통행속도 산출 정확도를 높여줌을 나타낸다.

차이검정을 이용한 논문의 통계활용 분석 (Analysis on Reports of Statistical Testings for Mean Differences)

  • 정재원;김증임;박혜숙;안숙희;조동숙;박소미
    • 여성건강간호학회지
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    • 제13권3호
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    • pp.211-218
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    • 2007
  • Purpose: This study aimed to evaluate the accuracy and adequacy of research papers reporting statistical testings for mean differences. Methods: Original research articles utilized t-test, Chi-square test, and ANOVA were reviewed from Korean Journal of Women Health Nursing published from the year 2004 to 2006. Seventy-six papers were evaluated in accordance with formatted criteria in respect to an inclusiveness of research title, accuracy of statistical methods and presentation styles, and errors in reporting statistical outcomes. Results: Research titles were quite comprehensive, however overall accuracy of statistical values and basic formats reached only 60 to 80% by items. Details of the presentation in the reporting of outcomes were not complied with the guidelines, which need careful concerns of the writers. Errors of English in table presentation were found in more than 30% of the papers. Conclusion: The outcome would be reflected in the submission guidelines for future writers. To reach the level comparable with internationally recognized nursing journals, concrete knowledge to apply statistical methods should be ensured in the processes of submission, reviews, and editing.

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간호대학생의 환자안전관리에 관한 지식과 태도 및 수행자신감이 교육요구도에 미치는 영향 (Influence of Knowledge, Attitude, and Confidence on Education Needs of Nursing Students for Patient Safety Management)

  • 송민선;양남영;최수빈
    • 가정∙방문간호학회지
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    • 제28권3호
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    • pp.285-294
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    • 2021
  • Purpose: The study examined the effects of knowledge, attitude, and confidence on the education needs of nursing students with respect to patient safety management. The participants were 119 students from nursing college. Data were analyzed using descriptive statistics, t-test, analysis of variance(ANOVA), Pearson's correlation coefficient, and multiple regression analysis with the SPSS program. Results: The student's educational needs with respect to patient safety management differed significantly by experience of patient safety accidents (p=.026) and experience of reporting medical errors (p<.001). Additionally, the educational needs with respect to patient safety management were found to have statistically significant positive relationships with both attitude (r=.39) and confidence (r=.37). Further, a total of 23% of the education needs with regard to patient safety management were explained by attitude and confidence. Conclusion: These results can be used to develop nursing students' education programs to enhance patient safety management competence be emphasizing the experience of patient safety accidents and reporting medical errors as well as improving the attitude and confidence of the students.

최근접 이웃 규칙 기반 프로토타입 선택과 편의-분산을 이용한 성능 평가 (Nearest-neighbor Rule based Prototype Selection Method and Performance Evaluation using Bias-Variance Analysis)

  • 심세용;황두성
    • 전자공학회논문지
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    • 제52권10호
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    • pp.73-81
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    • 2015
  • 이 논문은 프로토타입 선택 방법을 제안하고, 편의-분산 분해를 이용하여 최근접 이웃 알고리즘과 프로토타입 기반 분류 학습의 일반화 성능 비교 평가에 있다. 제안하는 프로토타입 분류기는 클래스 영역 내에서 가변 반지름을 이용한 다차원 구를 정의하고, 적은 수의 프로토타입으로 구성된 새로운 훈련 데이터 집합을 생성한다. 최근접 이웃 분류기는 새 훈련 집합을 이용하여 테스트 데이터의 클래스를 예측한다. 평균 기대 오류의 편의와 분산 요소를 분해하여 최근접 이웃 규칙, 베이지안 분류기, 고정 반지름을 이용한 프로토타입 선택 방법, 제안하는 프로토타입 선택 방법의 일반화 성능을 비교한다. 실험에서 제안하는 프로토타입 분류기의 편의-분산 변화 추세는 모든 훈련 데이터를 사용하는 최근접 이웃 알고리즘과 비슷한 편의-분산 추세를 보였으며, 프로토타입 선택 비율은 전체 데이터의 평균 약 27.0% 이하로 나타났다.

요구도 기반 항공우주 시스템 강건최적설계 기법 연구 (A New Process for the Requirements Based Aerospace System Design and Optimization)

  • 박형욱;이재우;변영환;정준
    • 한국항공우주학회지
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    • 제37권3호
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    • pp.255-266
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    • 2009
  • 본 연구에서는 기존 설계요구도 정립과정에서 고려할 수 없었던 설계자의 주관적인 판단의 배제 및 사용자 요구도의 변화, 시스템의 생산 및 운용환경에서 발생하는 오차 등을 개념 설계과정에서 고려하는 설계 프로세스를 개발하였다. 사용자 요구도를 의사결정 모델 및 시스템 엔지니어링 기법을 사용하여 구체화하여 대안형상들을 도출하고 그 가운데에서 우수한 대안형상을 선정한다. 선정된 대안형상들에 대해 최적설계 기법을 적용한 개념설계 결과를 도출하고 여기에 강건최적설계 기법을 적용하여 사용자의 요구를 만족하면서 오차에 영향을 적게 받는 결과를 도출하도록 하였다. 본 논문에서는 최근 각광받고 있는 Very Light Jet 항공기에 대하여 개발된 프로세스를 적용해 보았다.

여성건강간호학회지에 게재된 차이검정을 이용한 논문의 통계활용 분석 (Analysis on Reports of Statistical Testing for Mean Differences in Articles in the Korean Journal of Women Health Nursing)

  • 전은미;이은희;김증임;강희선;오현이;이은주;천숙희
    • 여성건강간호학회지
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    • 제17권4호
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    • pp.388-394
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    • 2011
  • Purpose: This study was done to evaluate the accuracy and adequacy of research studies reporting statistical testing for mean differences in studies of the Korean Journal of Women Health. Methods: Among articles published in the journal from 2007 to 2009, 75 studies using t-test, $x^2$-test, and ANOVA were identified. The studies were evaluated using structured analysis format for adequacy of research title, accuracy of statistical methods and presentation styles, and errors in reported statistical outcomes. Results: In this study, the research titles generally reflected the purpose of research and study designs. Thus the research titles were quite comprehensive. Also, there was compatibility between the research purpose and research design. Most important though, many errors were identified in the tables of results of the statistical analysis in articles published from 2004 to 2006. Conclusion: Over six years, 2004 to 2009, accuracy and adequacy of research studies has improved in many aspects. In order to enhance the completeness of the published papers and to be an internationally recognized nursing journal, close attention of the researchers, reviewers and editors is necessary to avoid errors and present adequate and accurate research.

엘만 순환 신경망을 사용한 전력 에너지 시계열의 예측 및 분석 (The Prediction and Analysis of the Power Energy Time Series by Using the Elman Recurrent Neural Network)

  • 이창용;김진호
    • 산업경영시스템학회지
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    • 제41권1호
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    • pp.84-93
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    • 2018
  • In this paper, we propose an Elman recurrent neural network to predict and analyze a time series of power energy consumption. To this end, we consider the volatility of the time series and apply the sample variance and the detrended fluctuation analyses to the volatilities. We demonstrate that there exists a correlation in the time series of the volatilities, which suggests that the power consumption time series contain a non-negligible amount of the non-linear correlation. Based on this finding, we adopt the Elman recurrent neural network as the model for the prediction of the power consumption. As the simplest form of the recurrent network, the Elman network is designed to learn sequential or time-varying pattern and could predict learned series of values. The Elman network has a layer of "context units" in addition to a standard feedforward network. By adjusting two parameters in the model and performing the cross validation, we demonstrated that the proposed model predicts the power consumption with the relative errors and the average errors in the range of 2%~5% and 3kWh~8kWh, respectively. To further confirm the experimental results, we performed two types of the cross validations designed for the time series data. We also support the validity of the model by analyzing the multi-step forecasting. We found that the prediction errors tend to be saturated although they increase as the prediction time step increases. The results of this study can be used to the energy management system in terms of the effective control of the cross usage of the electric and the gas energies.

Three-Way Balanced Multi-level Semi Rotation Sampling Designs

  • 박유성;최재원;김기환
    • 한국통계학회:학술대회논문집
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    • 한국통계학회 2002년도 춘계 학술발표회 논문집
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    • pp.19-24
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    • 2002
  • The two-way balanced one-level rotation design has been discussed (Park, Kim and Choi, 2001), where the two-way balancing is done on interview time in monthly sample and rotation group. We extend it to three-way balanced multi-level design under the most general rotation system. The three-way balancing is accomplished on interview time not only in monthly sample and rotation group but also in recall time. We present the necessary condition and rotation algorithm which guarantee the three-way balancing. We propose multi-level composite estimators (MCE) from this design and derive their variances and mean squared errors (MSE), assuming the correlation from the measurements of the same sample unit and three types of biases in monthly sample.

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지반성질 불확실성을 고려한 사면안정 해석 (Assessment of Slope Stability With the Uncertainty in Soil Property Characterization)

  • 김진만
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2003년도 봄 학술발표회 논문집
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    • pp.123-130
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    • 2003
  • The estimation of key soil properties and subsequent quantitative assessment of the associated uncertainties has always been an important issue in geotechnical engineering. It is well recognized that soil properties vary spatially as a result of depositional and post-depositional processes. The stochastic nature of spatially varying soil properties can be treated as a random field. A practical statistical approach that can be used to systematically model various sources of uncertainty is presented in the context of reliability analysis of slope stability Newly developed expressions for probabilistic characterization of soil properties incorporate sampling and measurement errors, as well as spatial variability and its reduced variance due to spatial averaging. Reliability analyses of the probability of slope failure using the different statistical representations of soil properties show that the incorporation of spatial correlation and conditional simulation leads to significantly lower probability of failure than obtained using simple random variable approach.

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Improved extended kalman filter design for radar tracking

  • Park, Seong-Taek;Lee, Jang-Gyu
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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    • pp.153-156
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    • 1996
  • A new filtering algorithm for radar tracking is developed based on the fact that correct evaluation of the measurement error covariance can be made possible by doing it with respect to the Cartesian state vector. The new filter may be viewed as a modification of the extended Kalman filter where the variance of the range measurement errors is evaluated in an adaptive manner. The structure of the proposed filter allows sequential measurement processing scheme to be incorporated into the scheme, and this makes the resulting algorithm favorable in both estimation accuracy and computational efficiency.

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