• 제목/요약/키워드: accuracy test

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Diagnostic accuracy of clinical tests to rule out elbow fracture: a systematic review

  • Giorgio Breda;Gianluca De Marco;Pierfranco Cesaraccio;Paolo Pillastrini
    • Clinics in Shoulder and Elbow
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    • 제26권2호
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    • pp.182-190
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    • 2023
  • Elbow traumas represent a relatively common condition in clinical practice. However, there is a lack of evidence regarding the most accurate tests for screening these potentially serious conditions and excluding elbow fractures. The purpose of this investigation was to analyze the literature concerning the diagnostic accuracy of clinical tests for the detection or exclusion of suspected elbow fractures. A systematic review was performed using the Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) guidelines. Literature databases including PubMed, Cumulative Index to Nursing and Allied Health Literature, Diagnostic Test Accuracy, Cochrane Library, the Web of Science, and ScienceDirect were searched for diagnostic accuracy studies of subjects with suspected traumatic elbow fracture investigating clinical tests compared to imaging reference tests. The risk of bias in each study was assessed independently by two reviewers using the Quality Assessment of Diagnostic Accuracy Studies 2 checklist. Twelve studies (4,485 patients) were included. Three different types of index tests were extracted. In adults, these tests were very sensitive, with values up to 98.6% (95% confidence interval [CI], 95.0%-99.8%). The specificity was very variable, ranging from 24.0% (95% CI, 19.0%-30.0%) to 69.4% (95% CI, 57.3%-79.5%). The applicability of these tests was very high, while overall studies showed a medium risk of bias. Elbow full range of motion test, elbow extension test, and elbow extension and point tenderness test appear to be useful in the presence of a negative test to exclude fracture in a majority of cases. The specificity of all tests, however, does not allow us to draw useful conclusions because there was a great variability of results obtained.

머시닝 센터에서 원운동정도 측정시스템의 개발 (Developement of Measuring System of Circular Motion Accuracy in Machining Center)

  • 김영석
    • 한국생산제조학회지
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    • 제4권3호
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    • pp.58-66
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    • 1995
  • It is very important to test motion accuracy and performance of NC machine tools as they affect that of all other machines machined by them in industry. In this paper, in has become possible to detect errors of linear displacement of radial direction for circular motion test using newly assembled magnetic type of linear scales so called Magnescale ball bar system, and to calculate time interval getting error motion data and revolution angle of circular motion in machining center using tick pulses come out from computer. And a set of error data gotten from test is expressed to a plot by computer treatment and to numerics of error motion by statistical treatment and results of test are compared with those of Renishaw ball bar system.

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Effect of the volumetric dimensions of a complete arch on the accuracy of scanners

  • Kim, Min-Kyu;Son, KeunBaDa;Yu, Beom-Young;Lee, Kyu-Bok
    • The Journal of Advanced Prosthodontics
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    • 제12권6호
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    • pp.361-368
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    • 2020
  • PURPOSE. The present study aimed to evaluate the accuracy of a desktop scanner and intraoral scanners based on the volumetric dimensions of a complete arch. MATERIALS AND METHODS. Seven reference models were fabricated based on the volumetric dimensions of complete arch (70%, 80%, 90%, 100%, 110%, 120%, and 130%). The reference models were digitized using an industrial scanner (Solutionix C500; MEDIT) for the fabrication of a computer-aided design (CAD) reference model (CRM). The reference models were digitized using three intraoral scanners (CS3600, Trios3, and i500) and one desktop scanner (E1) to fabricate a CAD test model (CTM). CRM and CTM were then superimposed using inspection software, and 3D analysis was conducted. For statistical analysis, one-way analysis of variance was used to verify the difference in accuracy based on the volumetric dimensions of the complete arch and the accuracy based on the scanners, and the differences among the groups were analyzed using the Tukey HSD test as a post-hoc test (α=.05). RESULTS. The three different scanners showed a significant difference in accuracy based on the volumetric dimensions of the complete arch (P<.05), but the desktop scanner did not show a significant difference in accuracy based on the volumetric dimensions of the complete arch (P=.808). CONCLUSION. The accuracy of the intraoral scanners was dependent on the volumetric dimensions of the complete arch, but the volumetric dimensions of the complete arch had no effect on the accuracy of the desktop scanner. Additionally, depending on the type of intraoral scanners, the accuracy differed according to the volumetric dimensions of the complete arch.

Grid Encoder를 이용한 NC공작기계 동적정밀도 측정에 관한 연구 (A Study on Measurement of Dynamic Accuracy Using Grid Encoder in NC Machine Tools)

  • 이찬호;이방희;김성청
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.378-381
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    • 2003
  • Efficient development of method on a performance evaluation for machine tools has been regarded as the most important work for accuracy and quality enhancement to every user and manufacturer. A evaluation method of accuracy for machine tools has been studied recently according to the rapid increase of interest in precision machine tools. To this point of view, the circular interpolation test of machine tools is recognized as the most useful method to distinguish a dynamic accuracy of NC machine tools by ISO and ANSI/ASME, etc. In this paper, we have studied and developed the form measurement system with grid encoder to analyse the final accuracy of NC machine tools. we have analyzed the servo system error and geometric error of NC machine tools through measuring a dynamic error signal by this system. and then we verified the experimental result and enhanced the reliability by means of comparing the characteristics of the developed system with the kinematic ball-bar system.

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수치지도의 정확도 검정에 관한 연구 (A Study on the Accuracy Assessment of Digital Map)

  • 김병국;최정민;김은모
    • 한국측량학회지
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    • 제16권2호
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    • pp.319-326
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    • 1998
  • 본 연구에서는 막대한 비용과 노력을 들여서 제작된 수치지도의 위치정확도를 실험적으로 판단하고자 하였다. 수치지도의 위치정확도 평가를 위해서 GPS와 Total Station을 이용한 현지측량을 실시하였으며, 현지측량의 성과와 수치지도를 비교함으로써 1:5,000 수치지도의 위치정확도를 판단해 보았다. 그리고, 1:5,000 수치지도의 이론적인 기대정확도와 현지 측량성과를 비교하여 향후 수치지도의 위치정확도 평가방법 및 개선을 위한 연구방향을 고찰해 보았다.

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Machining Center의 공간정도 측정장치의 개발 (Developement of Measuring Units of Space Motion Accuracy in Machining Center)

  • 김영석;남궁석
    • 한국정밀공학회지
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    • 제12권2호
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    • pp.37-47
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    • 1995
  • In recent years, it has been variously developed for testing the accuracy of circular motion of NC machine tools, for example Telescoping Ball Bar Method by Bryan, Circular test Method by Knapp and $r^{-{\theta} }$ Method by Tsutsumi etc., but these methods are all 2-dimentional measuring methods on plane. These simple methods of circular motion accuracy test of NC machine tools have been studied by many reserchers as above, but it is not yet settled in the code of measuring methods of motion errors of NC machine tools, because of errors of measuring units and sensors, and also especially the difficulties of centering of measuring units and the spindle of machining center. In this paper, in use of 2 rotary encoders and 1 magnetic type linear scale with resolution of 0.5 .mu. m, it has become possible for measuring of 3 dimentional space motion accuracy.

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정밀유도무기 시험평가 수량 결정 및 명중률 검증 방법론 (Methodologies to Decide the Number of Samples and to Verify an Accuracy Rate of the Precise Guided Missiles for Test and Evaluation)

  • 이문걸;황승훈;백승령
    • 한국군사과학기술학회지
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    • 제18권5호
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    • pp.558-565
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    • 2015
  • The current methods, such as Binomial Probability Distribution or T-test, to calculate the number of samples of Precise Guided Missiles(PGMs) for test and evaluation are statistically problematic to make reasonable decisions thus use the budget efficiently. Also, the method to verify an accuracy rate of the PGMs using these old methods seems to be lack of objectiveness. This paper presents an effective, efficient solution adapted from the clinical medicine testing method of healthcare industry research, which may overcome our problems. This method considers and addresses both manufacturers' and consumers' risk simultaneously. By taking into account the weapon system project characteristics which take a relatively longer time and require higher-level budget, this approach also suggests a reasonable and feasible method to determine the amount of samples of the PGMs and making a criterion to verify an accuracy rate of the missiles that are required to test. Thus, this method is expected to contribute to acquisition and operations of high-reliability PGMs by MND and its field-users.

Identification of Transformed Image Using the Composition of Features

  • Yang, Won-Keun;Cho, A-Young;Cho, Ik-Hwan;Oh, Weon-Geun;Jeong, Dong-Seok
    • 한국멀티미디어학회논문지
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    • 제11권6호
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    • pp.764-776
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    • 2008
  • Image identification is the process of checking whether the query image is the transformed version of the specific original image or not. In this paper, image identification method based on feature composition is proposed. Used features include color distance, texture information and average pixel intensity. We extract color characteristics using color distance and texture information by Modified Generalized Symmetry Transform as well as average intensity of each pixel as features. Individual feature is quantized adaptively to be used as bins of histogram. The histogram is normalized according to data type and it is used as the signature in comparing the query image with database images. In matching part, Manhattan distance is used for measuring distance between two signatures. To evaluate the performance of the proposed method, independent test and accuracy test are achieved. In independent test, 60,433 images are used to evaluate the ability of discrimination between different images. And 4,002 original images and its 29 transformed versions are used in accuracy test, which evaluate the ability that the proposed algorithm can find the original image correctly when some transforms was applied in original image. Experiment results show that the proposed identification method has good performance in accuracy test. And the proposed method is very useful in real environment because of its high accuracy and fast matching capacity.

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고정밀 스핀들의 회전정밀도 측정 오차 분리법에 관한 연구 (A study on the Error Separation Method in Rotation Accuracy Measurement of High Precision Spindle Unit)

  • 김상화;김병하;진용규
    • 한국기계가공학회지
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    • 제13권1호
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    • pp.78-84
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    • 2014
  • The rotation of a spindle unit must be accurate for high-quality machining and to improve the quality of the machine tools.Therefore, the proper measurement of the rotation accuracy and ensuring a proper analysis are very important. Separate processes are necessary because spindle errors and roundness errors associated with the test balls can both factor into the measured rotation error values. We used three methods to discern test ball errors and analyzed which could be deemed as the most proper technique in a test of the rotation accuracy of the main spindle of a machine tool.

Agricultural tractor roll over protective structure (ROPS) test using simplified ROPS model

  • Ryu-Gap Lim;Young-Sun Kang;Dae-Hyun Lee;Wan-Soo Kim;Jun-Ho Lee;Yong-Joo Kim
    • 농업과학연구
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    • 제49권4호
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    • pp.823-835
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    • 2022
  • In this study, the feasibility of alternative tractor Roll Over Protective Structure (ROPS) designed to evaluate conditions required for testing was confirmed. In accordance with Organization for Economic Cooperation and Development (OECD) code 4, the required load energy of the tractor ROPS was determined. First, the tractor ROPS test was performed and a repeated test was performed using a simplified ROPS as an alternative tractor ROPS. The test procedure is first rearward, second lateral, and last forward based on ROPS. The load test device consists of a load cell that measures force and a LVDT that measures deformation. Precision was confirmed by calculating the relative standard deviation of the simplified ROPS repeated test. Accuracy was analyzed by calculating the mean relative error between the mean measured values in the simplified ROPS test and the tractor ROPS test. As a result, the relative standard deviation was less than 2.5% for force and 3.3% for maximum deformation overall, showed the highest precision in lateral load. The mean relative error value for force measured at the lateral load of simplified ROPS was 0.5%, showing the highest accuracy. In the front load test, the mean relative error of maximum deformation was 20.5%, showing the lowest accuracy. The mean relative error (MRE) was high in the forward load test was because of structural factors of the ROPS. The simplified ROPS model is expected to save money and time spent preparing tractors.