• Title/Summary/Keyword: accuracy test

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A NEW SYSTEM OF VISUAL PRESENTATION OF ANALYSIS OF TEST PERFORMANCE: THE 'DOUBLE-RING' DIAGRAM

  • Stefadouros Miltiadis A.
    • 대한예방의학회:학술대회논문집
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    • 1994.02b
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    • pp.142-149
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    • 1994
  • Substitution of graphic representation for extensive lists of numerical statistical data is highly desirable by both editors and readers of medical journals, faced with an exploding abundance of contemporary medical literature. A novel graphic tool. the 'double-ring diagram', is described herein which permits visual representation of information regarding certain statistical variables used to describe the performance of a test or physical sign in the diagnosis of a disease. The diagram is relatively easy to construct on the basis of a number of primary data such as the prevalence and the true positive, true negative. false positive and false negative test results. These values are reflected in the diagram along with the values of other statistical variables derived from them. such as the sensitivity. specificity, predictive values for positive and negative test result. and accuracy. This diagram may be useful in visualizing a test's performance and facilitating visual comparison of performance of two or more tests.

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The Comparison of Motor Control During Tracking in the Knee Joint of Subjects With Stroke (무릎 관절 추적 과제에 따른 편마비 환자의 운동조절 비교)

  • Chung, Yi-Jung;Cho, Sang-Hyun;Jeon, Hye-Seon
    • Physical Therapy Korea
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    • v.12 no.3
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    • pp.39-45
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    • 2005
  • Tracking is an experimental paradigm that can be used to study information processing in continuous movements involving accurate, ongoing control of motor performance. The purpose of this study was to identify the effects of knee tracking performance. Six patients with hemiplegia and six age-matched controls participated in the study. The tracking test was administrated. It was composed with regular ranges of $0^{\circ}C$ to $40^{\circ}C$ and randomized range .2 to .4 Hz. Using the Mann-Whitney U test, a comparison was made between subjects who had suffered from stroke and subjects who were well coordinated. The Wilcoxon Matched Pairs Signed Ranks Test was used to compare and analyze the paretic and nonparetic sides of the stroke patients. The results of study were as follows: accuracy index of the tracking test was significantly higher on the control side than paretic and nonparetic sides. Accuracy index scores were significantly higher for nonparetic sides with stroke compared with paretic sides with stroke. This study shows tracking is impaired in paretic and nonparetic knee of subjects with stroke.

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Injection Molded Microcellular Plastic Gear (II) - Characteristics of the Counter Pressurized Microcellular Plastic Gear - (초미세발포 플라스틱 기어에 관한 연구 (II) - 카운터프레셔 초미세발포 플라스틱 기어의 특성 -)

  • Ha Young Wook;Takahashi Hideo;Chong Tae Hyong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.5 s.236
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    • pp.655-662
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    • 2005
  • This paper investigates the improvement of accuracy and fatigue life of the developed counter pressurized microcellular gears of polyacetal. It is shown that the fatigue life and operational characteristics of the counter pressurized microcellular gears are more improved than conventional injection molded plastic gears by the dynamic gear durability test. For the cases of test sea.5. conventional injection molded sea.5(SGea.) and counter pressurized microcellular gears(CGear) are manufactured. Durability test is performed on both conventional lnjection molded gears and counter pressurized microcellular gears. Accuracy variation and operational characteristics on fatigue life, wear and tooth surface temperature of CGear and Scear are compared and represented. Operational characteristics of the proposed counter pressurized microcellular gears show a good result in this research. The durability limit of counter pressurized microcellular gears is also obtained, and represented by a function of unit load as well as by a function off-factor.

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

  • Chung, Chae-Weon;Kim, Jeung-Im;Park, Hye-Sook;Ahn, Suk-Hee;Cho, Dong-Sook;Park, So-Mi
    • Women's Health Nursing
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    • v.13 no.3
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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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Statistical Analysis on the Sources of Variance in Proficiency Test of Quantitative Analysis of Medicines (의약품 함량분석 정도관리에서의 변이 요인에 대한 통계분석)

  • Cho, Jung-Hwan
    • Journal of Pharmaceutical Investigation
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    • v.37 no.1
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    • pp.27-37
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    • 2007
  • Proficiency test is an essential tool far ensuring analytical ability of analytical chemists and analytical institutes. Usually, the standard protocol for proficiency test is focused on acceptability of reported analytical results of participants by calculating z-scores and related diagnostic parameters. The ultimate goal of this process is to reveal the sources of variability of analytical results and to find the way to reduce their influence. In this study, the method of analysis of variance (ANOVA) was applied to the analytical data collected from qualify control departments of pharmaceutical companies in KyungIn province in Korea in the year of 2000. As influencing factors of variability of analytical results, the use of internal standards for liquid and gas chromatograpy, the educational and professional background of participants, geological locations and yearly production sizes of participating companies were evaluated. To evaluate the variability in accuracy of analytical results, absolute differences from sample mean and sample median were used and to evaluate variability in precision of individual participants, the reported standard deviation of each participant was used. As a result, the use of internal standards in gas chromatographic analysis, participants' academic background and the yearly production sizes of pharmaceutical companies showed statistically significant influence to the accuracy and the precision of the reported analytical results used in this study.

Servo Mismatch Estimation of Miniaturized Machine Tools Using Laser Tracker (레이저 트래커를 이용한 소형 공작기계의 서보 불일치 추정)

  • Lee, Hoon Hee;Kweon, Sung Hwan;Son, Jin Gwan;Yang, Seung Han
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.8
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    • pp.683-689
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    • 2016
  • Servo mismatch, which affects positioning accuracy of multi-axis machine tools, is usually estimated via the circular test. However, due to mechanical restrictions in measuring instruments, the circular test using a double ball-bar is difficult to apply in miniaturized or super-large sized machine tools. Laser trackers are widely used to measure the form accuracy of parts and the positioning accuracy of driving systems. In this paper, a technique for the servo mismatch estimation of multi-axis machine tools is proposed via the circular test using a laser tracker. To verify the proposed technique, experiments using a double ball-bar and laser tracker are conducted in a 3-axis machine tool. The difference in the evaluation results is 0.05 msec. The servo mismatch for the miniaturized machine tool is also evaluated using the proposed technique.

Analysis of Effect by Duration of Cryotherapy in the Posterior region of Neck for College Students

  • Ji Hong Chang
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.16 no.5
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    • pp.301-306
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    • 2023
  • Attention is a fundamental aspect in the cognitive process of human. Cognitive system of human body requires to focus on selected information among a vast amount of information from sensory organs. It has widely studied that various environmental factors affected the level of attention; however, few researches have aimed to the effect of direct cryotherapy. In this research, level of attention was studied comparing sub-indexes of FAIR test between groups with different duration of direct cryotheapy to the back of neck. FAIR test is a evaluation tool for visual attention consisting of three sub-indexes. Selective attention, accuracy of attention, and persistence of attention can be independently analyzed by FAIR test. In the analysis of selective attention, cryotherapy for 5 to 20 minutes showed higher result than cryotherapy for 40 minutes. In the analysis of persistence of attention, cryotherapy for 5 to 15 minutes showed higher result than cryotherapy for 40 minutes. Overall, selective attention and persistence of attention turns out to be maximized between 5 to 20 minutes of cryotherapy and tends to decrease afterwards. However, accuracy of attention does not seem to be affected by the duration of cryotherapy. Correlation between selective attention and the skin temperature by cryotherapy tends to be negative supporting the findings by ANOVA and post-hoc test. Correlation between persistence of attention and the skin temperature showed similar results.

Accuracy of the Point-Based Image Registration Method in Integrating Radiographic and Optical Scan Images: A Pilot Study

  • Mai, Hai Yen;Lee, Du-Hyeong
    • Journal of Korean Dental Science
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    • v.13 no.1
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    • pp.28-34
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    • 2020
  • Purpose: The purpose of this study was to investigate the influence of different implant computer software on the accuracy of image registration between radiographic and optical scan data. Materials and Methods: Cone-beam computed tomography and optical scan data of a partially edentulous jaw were collected and transferred to three different computer softwares: Blue Sky Plan (Blue Sky Bio), Implant Studio (3M Shape), and Geomagic DesignX (3D systems). In each software, the two image sets were aligned using a point-based automatic image registration algorithm. Image matching error was evaluated by measuring the linear discrepancies between the two images at the anterior and posterior area in the direction of the x-, y-, and z-axes. Kruskal-Wallis test and a post hoc Mann-Whitney U-test with Bonferroni correction were used for statistical analyses. The significance level was set at 0.05. Result: Overall discrepancy values ranged from 0.08 to 0.30 ㎛. The image registration accuracy among the software was significantly different in the x- and z-axes (P=0.009 and <0.001, respectively), but not different in the y-axis (P=0.064). Conclusion: The image registration accuracy performed by a point-based automatic image matching could be different depending on the computer software used.

Measuring the Positional Accuracy of GIS Polygon Data (GIS 폴리곤 데이터의 위치정확도 측정 방법)

  • Hong, Sung-Eon
    • Journal of Korean Society for Geospatial Information Science
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    • v.14 no.4 s.38
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    • pp.3-10
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    • 2006
  • This study proposes a method to measure the positional accuracy of the implemented GIS polygon data. Also, it aims to present a possibility to analyze the occurrence types of positional errors by improving the measuring methods of positional accuracy based on the existing individual methods and by linking individual methods. As a result of the actual application of the methodology to the test area, it was possible to measure the positional accuracy in target test areas and to analyze the occurrence causes (types) of positional errors through each index linking (linking methodologies). Also, research results allowed confirming the applicability of the methodology. However, complementary research for each standard numerical value is recommended in order to ensure the validity of methodology.

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Coupler Implementation and Antenna Tracking Accuracy Analysis for Ku-band Multi-mode Monopulse Satellite Tracking System (Ku 대역 다중모드 모노펄스 위성추적시스템을 위한 커플러 구현 및 안테나 추적정확도 분석)

  • Lee, Jaemoon;Lim, Jaesung;Park, Dohyun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.3
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    • pp.363-370
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    • 2016
  • This paper proposes a Ku-band multi-mode coupler and its monopulse tracking system, which can be applied to a unmaned aircraft vehicle(UAV) platform. In general, the carrier-to-noise(C/N) level of the beacon signal from a Ku-band commercial satellite is relatively weak compared to that of a military satellite because the Ku-band satellite has been designed for commercial services. Therefore, this paper proposes a coupler and its multi-mode monopulse tracking system satisfying the tracking accuracy under a low C/N environment and analyzes the tracking accuracy. After that, we perform a real satellite tracking test and compare the accuracy of the test with the analysis result before validating the performance of the architecture of the proposed satellite tracking system.