• 제목/요약/키워드: Diagnostic Errors

검색결과 148건 처리시간 0.023초

Diagnostic In Spline Regression Model With Heteroscedasticity

  • Lee, In-Suk;Jung, Won-Tae;Jeong, Hye-Jeong
    • Journal of the Korean Data and Information Science Society
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    • 제6권1호
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    • pp.63-71
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    • 1995
  • We have consider the study of local influence for smoothing parameter estimates in spline regression model with heteroscedasticity. Practically, generalized cross-validation does not work well in the presence of heteroscedasticity. Thus we have proposed the local influence measure for generalized cross-validation estimates when errors are heteroscedastic. And we have examined effects of diagnostic by above measures through Hyperinflation data.

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고압전동기 Off-Line 절연진단시험 효율개선을 위한 데이터자동취득 및 원격진단시스템 구축 (Development of Automatic Data Acquisition & Remote Diagnostic System for Improving Efficiency of High-Voltage Motors Off-Line Insulation Diagnostic Test)

  • 강상무;강대정;한현석;김원경
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2015년도 제46회 하계학술대회
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    • pp.707-708
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    • 2015
  • This paper proposes a method for improving efficiency of high-voltage motors off-line insulation diagnostic test. The conventional manual test method has measurement errors and excessive processing time. We developed the KITAS system and solved these problems by using the instrument remote control and communication technology. The result of proficiency testing by interlaboratory comparisons using Power Factor Tip-Up test was '${\mid}E_n{\mid}$ < 1'. It was possible to confirm the validity of acquired data from the KITAS and establish a remote diagnostic system for easy access without physical limitations.

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Evaluation of linear measurements of implant sites based on head orientation during acquisition: An ex vivo study using cone-beam computed tomography

  • Sabban, Hanadi;Mahdian, Mina;Dhingra, Ajay;Lurie, Alan G.;Tadinada, Aditya
    • Imaging Science in Dentistry
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    • 제45권2호
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    • pp.73-80
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    • 2015
  • Purpose: This study evaluated the effect of various head orientations during cone-beam computed tomography (CBCT) image acquisition on linear measurements of potential implant sites. Materials and Methods: Six dry human skulls with a total of 28 implant sites were evaluated for seven different head orientations. The scans were acquired using a Hitachi CB-MercuRay CBCT machine. The scanned volumes were reconstructed. Horizontal and vertical measurements were made and were compared to measurements made after simulating the head position to corrected head angulations. Data was analyzed using a two-way ANOVA test. Results: Statistical analysis revealed a significant interaction between the mean errors in vertical measurements with a marked difference observed at the extension head position (P<0.05). Statistical analysis failed to yield any significant interaction between the mean errors in horizontal measurements at various head positions. Conclusion: Head orientation could significantly affect the vertical measurements in CBCT scans. The main head position influencing the measurements is extension.

JNI를 이용하여 진단된 IGES의 가시화 (Visualization of Diagnosed IGES by Java Native Interface)

  • 박상호;윤형선;이병훈;김준형;김덕수
    • 산업경영시스템학회지
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    • 제26권2호
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    • pp.23-28
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    • 2003
  • This research explains visualization of diagnostic system of 3D CAD data, IGES (Initial Graphics Exchange Specification), by using JNI(Java Native Interface) to connect between C++ and Java programming. The diagnostic system is to analyze IGES clearly by identifying errors and anomalies with respect to the diagnosis of geometry and topology of entities. The output of the system is IGES file including . error information which can be visualized with different colors by several commercial visualization systems. The paper focuses on the visualization of the result IGES which can be extended to web based application over internet.

직류전압감쇄법을 이용한 전력케이블의 절연열화진단 (Diagnostics of Power Cables using DC Voltage Decay method)

  • 이동영;김상준;김주용;송일근
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 E
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    • pp.1688-1691
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    • 1997
  • In this work, we have developed the off-line diagnostic system for power cable insulation using DC voltage decay method to diagnose the insulation degradation of underground power cables. Measurement errors of diagnostic system are less than 1% for $1T{\Omega}$ internal resistor. We have also developed measurement and diagnostic programs for win95 which is suitable for the database construction and the management of data. We could conclude that it is possible to apply this system to the multi-grounded underground cable systems.

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Spatial Compounding of Ultrasonic Diagnostic Images for Rotating Linear Probe with Geometric Parameter Error Compensation

  • Choi, Myoung Hwan;Bae, Moo Ho
    • Journal of Electrical Engineering and Technology
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    • 제9권4호
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    • pp.1418-1425
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    • 2014
  • In ultrasonic medical imaging, spatial compounding of images is a technique where ultrasonic beam is steered to examine patient tissues in multiple angles. In the conventional ultrasonic diagnostic imaging, the steering of the ultrasonic beam is achieved electronically using the phased array transducer elements. In this paper, a spatial compounding approach is presented where the ultrasonic probe element is rotated mechanically and the beam steering is achieved mechanically. In the spatial compounding, target position is computed using the value of the rotation axis and the transducer array angular position. However, in the process of the rotation mechanism construction and the control system there arises the inevitable uncertainties in these values. These geometric parameter errors result in the target position error, and the consequence is a blurry compounded image. In order to reduce these target position errors, we present a spatial compounding scheme where error correcting transformation matrices are computed and applied to the raw images before spatial compounding to reduce the blurriness in the compounded image. The proposed scheme is illustrated using phantom and live scan images of human knee, and it is shown that the blurriness is effectively reduced.

영작문 자동 채점 시스템에서의 중복 보고 오류 제거를 통한 성능 향상 (Accuracy Improvement of an Automated Scoring System through Removing Duplicately Reported Errors)

  • 이현아;김지은;이공주
    • 정보처리학회논문지B
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    • 제16B권2호
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    • pp.173-180
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    • 2009
  • 영어 작문 자동 채점 시스템은 수험자가 작성한 영작문을 사람의 개입 없이 시스템이 처리하여 점수나 피드백을 줄 수 있는 시스템이다. 본 논문에서 개발한 영작문 자동 채점 시스템은 단어 단계, 구문 단계, 의미 단계의 세 단계 처리 과정을 통해서 오류를 탐지하고 탐지된 오류 개수를 기반으로 채점 점수를 결정한다. 이와 같이 독립적인 세 단계의 처리 과정에서 오류를 탐지하므로 동일한 오류 현상에 대해 서로 다른 단계에서 서로 다른 이름으로 오류를 탐지하는 경우가 발생할 수 있다. 이는 결과적으로 전체 시스템의 채점 점수의 정확도를 저하시키는 원인이 된다. 본 논문에서는 동일한 오류 현상에 대해 서로 다른 단계에서 탐지된 오류 쌍을 '중복 보고 오류'라고 정의한다. 본 논문에서는 중복 보고 오류를 찾는 방법을 제안하고 중복 보고 오류 제거를 통해 영작문 자동 채점 시스템의 채점 점수를 향상시킬 수 있음을 보인다.

자궁경부 편평상피병변에서 자궁경부질도말 세포검사의 진단정확도 : 481예의 세포-조직 상관관계 (Diagnostic Accuracy of Cervicovaginal Cytology in the Detection of Squamous Epithelial Lesions of the Uterine Cervix; Cytologic/Histologic Correlation of 481 Cases)

  • 진소영;박상모;김미선;진윤미;김동원;이동화
    • 대한세포병리학회지
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    • 제19권2호
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    • pp.111-118
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    • 2008
  • Background : Cervicovaginal cytology is a screening test of uterine cervical cancer. The sensitivity of cervicovaginal cytology is less than 50%, but studies of cytologic/histologic correlation are limited. We analyzed the diagnostic accuracy of cervicovaginal cytology in the detection of the squamous epithelial lesions of the uterine cervix and investigate the cause of diagnostic discordance. Materials and Methods : We collected a total of 481 sets of cervicovaginal cytology and biopsies over 5 years. The cytologic diagnoses were categorized based on The Bethesda System and the histologic diagnoses were classified as negative, flat condyloma, cervical intraepithelial neoplasia (CIN) I, CIN II, CIN III, or squamous cell carcinoma. Cytohistologic discrepancies were reviewed. Results: The concordance rate between the cytological and the histological diagnosis was 79.0%. The sensitivity and specificity of cervicovaginal cytology were 80.6% and 92.6%, respectively. Its positive predictive value and negative predictive value were 93.7% and 77.7%, respectively. The false negative rate was 19.4%. Among 54 false negative cytology cases, they were confirmed by histology as 50 flat condylomas, 2 CIN I, 1 CIN III, and 1 squamous cell carcinoma. The causes of false negative cytology were sampling errors in 75.6% and interpretation errors in 24.4%. The false positive rate was 7.4%. Among 15 false positive cytology cases, they were confirmed by histology as 12 atypical squamous cells of undetermined significance (ASCUS) and 3 low grade squamous intraepithelial lesions (LSIL). The cause of error was interpretation error in all cases. The overall diagnostic accuracy of cervicovaginal cytology was 85.7%. Conclusions : Cervicovaginal cytology shows high overall diagnostic accuracy and is a useful primary screen of uterine cervical cancer.

Sample size and statistical power consideration for diagnostic test research

  • Kim, Eu Tteum;Park, Choi Kyu;Pak, Son Il
    • 대한수의학회지
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    • 제48권3호
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    • pp.357-361
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    • 2008
  • Although power analysis is of important tool of research, investigators in veterinary medicine are unaware of the concepts of the statistical power. Two types of error occur in classical hypothesis testing and, those errors should be avoided, if possible. Since power is highly dependent on the sample size, whenever declaring non-statistically significant result they should consider the potential for committing a Type II error in their studies, which refers to the probability of falsely stating that two treatments are equivalent despite true difference between them. Also, sample size determination is one of the most important tasks facing the researcher when planning a diagnostic study, and provides valuable information on the characteristics of a test performance. This type of analysis forms the basis for proper interpretation of test results. The aim of this article was to re-evaluate some selected studies on diagnostic test reported in the domestic veterinary publications to determine the power and necessary sample size for inequality testing to ensure the desired power. Power calculations were illustrated using real-life examples of comparison of a new test and a reference test for detecting antibodies of various animal diseases. Factors affecting to the power were also discussed.