• 제목/요약/키워드: Accuracy Measure

검색결과 2,031건 처리시간 0.031초

대면적 가공물의 마이크로 그루빙에서 고속 절삭 깊이 제어를 통한 미세형상의 정밀도 향상 (Improvement of Form Accuracy of Micro-Features on Thin, Large-area Plate using Fast Depth Adjustment in Micro-grooving)

  • 강동배;손성민;이효렬;안중환
    • 한국생산제조학회지
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    • 제22권3호
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    • pp.408-413
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    • 2013
  • Micro-features such as grooves and lenses, which perform optical functions in flat displays, should be manufactured with a good form accuracy because this is directly related to their optical performance. As the size of the display increases, it is very difficult to maintain a high relative accuracy because of the inherent geometric errors such as the waviness of a large-area plate. In this paper, the optical effect of these geometric errors is investigated, and surface-referenced micro-grooving to measure and compensate for such geometric errors on line is proposed to improve the form accuracy of the micro-grooves. A PZT-based fast depth adjustment servo system is implemented in the tool holder to maintain a uniform groove depth in reference to the wavy surface. Through experiments, the proposed method is shown to be an efficient way to produce high-quality micro- grooves on a wavy die surface.

구면좌표계식 기구를 이용한 인공치아의 3차원 측정시스템 개발 (Development of 3D Measuring System for Artificial Pontic using Spherical Coordinate System Mechanism)

  • 맹희영;성봉현
    • 한국생산제조학회지
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    • 제19권4호
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    • pp.427-433
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    • 2010
  • With recent increased demand for reverse engineering in dental machining, the 3D laser scanner is widely used for inspection of artificial pontic. In order to overcome the optical drawback of laser scanner, such as irregular scatter, direction of beam, and the influence of surface integrity, it is developed in this study a new 3D measuring system for artificial pontic using spherical coordinate system mechanism by point laser sensor, which keeps the direction of beam normal to surface consistently. The comprehensive integrated system is established to evaluate the improvement of accuracy with data acquisition system. The experimental results for measuring a master ball and pontic models shows the excellent form accuracy and repeatability compared with conventional apparatus. Also, these results shows the possibility to apply this system for the measuring purpose within 0.05mm accuracy of pontic at the sharp edge or margin contour, which was difficult to measure at the conventional systems.

무선 센서를 활용한 요추 가동 범위의 실시간 3차원 측정 (Real-time 3-Dimensional Measurement of Lumbar Spine Range of Motion using a Wireless Sensor)

  • 정우혁;지혜미;박재현
    • 제어로봇시스템학회논문지
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    • 제18권8호
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    • pp.713-718
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    • 2012
  • Lumber spine range of motion has been used to measure of physical and functional impairment by various tools from a ruler to 3D kinematic devices. However, pre-existing tools have problems in either movement or accuracy and reliability limitations. Accurate devices are limited by fixed space whereas simple devices are limited in measuring complex movements with less accuracy. In order to solve the location, movement and accuracy limitations at once, we have developed a novice measurement device equipped with accelerometer sensor and gyroscope sensor for getting three-dimensional information of motion. Furthermore, Kalman filter was applied to the algorithm to improve accuracy. In addition, RF wireless communication was added for the user to conveniently check measured data in real time. Finally, the measurement method was improved by considering the movement by a reference point. An experiment was conducted to test the accuracy and reliability of the device by conducting a test-retest reliability test. Further modification will be conducted to used the device in various joints range of motion in clinical settings in the future.

편광현미경을 이용한 전자적근관장측정기의 정확성에 관한 연구 (EVALUATION OF THE ACCURACY OF THE ELECTRONIC APEX LOCATOR USING THE POLARIZING MICROSCOPE)

  • 박한수;윤수한
    • Restorative Dentistry and Endodontics
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    • 제17권1호
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    • pp.235-243
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    • 1992
  • The purpose of this study was to evaluate the accuracy of an electronic apex locator, the Neosono - M, in determining the location of the cementodentinal junction. A total of 26 teeth with 46 canals were evaluated. The apex locator was used to locate the file and the teeth extracted. The specimen were prepared with highspeed burs and sandpaper discs to a thickness of $250{\sim}300{\mu}m$. Distances were measured from the cementodentinal junction with the use of polarizing microscope. Measurements made by the apex locator were also compared with those by the X - ray. The results were as follows. 1. The apex locator and X - ray were to measure a mean value of 0.17, 0.45mm coronal to the CDJ respectively. There was no significant difference between the accuracy of the apex locator and that of X - ray. 2. There was no significant difference between the accuracy of apex locator in vital and in nonvital teeth, and between in narrow and in wide canals. 3. The files in nonvital and narrow group were apical to the CDJ significantly than those of vital and narrow, vital and wide, and non vital and wide groups.

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진단검사의 특성 평가를 위한 Receiver Operating Characteristic (ROC) 곡선의 활용 (Application of Receiver Operating Characteristic (ROC) Curve for Evaluation of Diagnostic Test Performance)

  • 박선일;오태호
    • 한국임상수의학회지
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    • 제33권2호
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    • pp.97-101
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    • 2016
  • In the field of clinical medicine, diagnostic accuracy studies refer to the degree of agreement between the index test and the reference standard for the discriminatory ability to identify a target disorder of interest in a patient. The receiver operating characteristic (ROC) curve offers a graphical display the trade-off between sensitivity and specificity at each cutoff for a diagnostic test and is useful in assigning the best cutoff for clinical use. In this end, the ROC curve analysis is a useful tool for estimating and comparing the accuracy of competing diagnostic tests. This paper reviews briefly the measures of diagnostic accuracy such as sensitivity, specificity, and area under the ROC curve (AUC) that is a summary measure for diagnostic accuracy across the spectrum of test results. In addition, the methods of creating an ROC curve in single diagnostic test with five-category discrete scale for disease classification from healthy individuals, meaningful interpretation of the AUC, and the applications of ROC methodology in clinical medicine to determine the optimal cutoff values have been discussed using a hypothetical example as an illustration.

항공 무장정확도 시험평가 방법에 관한 연구 (A Study on the T&E Method for the Aircraft focused on Weapon Accuracy)

  • 현준호;강성진
    • 한국국방경영분석학회지
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    • 제33권1호
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    • pp.117-133
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    • 2007
  • 무장정확도는 무기체계 획득의 기본 지표가 되는 성능으로 이에 대한 정확한 개념 정립과 시험평가 방법의 설정이 요구된다. 기존의 항공무장의 정확도 시험평가 방법은 무장의 탄착형태를 정확하게 고려하지 않았다. 본 연구는 확률 및 통계기법을 이용하여 최적 CEP 계산법과 각 시험평가 단계별 평가방안을 제시하였다. 먼저, 알려진 여러 무장정확도 계산법 중 항공무장의 탄착형태를 반영하는 최적 CEP 계산법으로 록히드마틴 CEP법과 존슨 CEP법을 추천하며, 시험평가 단계별 최적의 시험평가 방법을 제시하였다. 본 연구결과는 항공무장의 정확도 평가에 유용하게 사용될 수 있을 것이다.

The Accuracy of Glasgow Coma Scale Knowledge and Performance among Vietnamese Nurses

  • Hien, Nguyen Thi;Chae, Sun-Mi
    • Perspectives in Nursing Science
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    • 제8권1호
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    • pp.54-61
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    • 2011
  • Purpose: The purpose of this study was to investigate the accuracy of Glasgow Coma Scale (GCS) knowledge and performance among Vietnamese nurses. Methods: A cross-sectional descriptive study was conducted using a questionnaire pertaining to the nurses' knowledge of GCS and a structured evaluation tool to measure the accuracy of their GCS scores. A total of 94 Vietnamese nurses participated in this study, all from a general hospital in Ho Chi Minh City, Vietnam. Data were analyzed by conducting a t-test, a $x^2$ test, and ANOVA. Results: This study found that the vast majority of the nurses (>90%) responded correctly to questions regarding their GCS basic knowledge; however, 52.1% of the nurses answered incorrectly questions related to clinical scenarios requiring the application of the basic knowledge. Regarding the GCS performance, the nurses demonstrated acceptable accuracy rates for each component of GCS, but those who scored well in all three components accounted for only 42.6% of the subject group. These findings indicate that the Vietnamese nurses are not able to integrate their GCS knowledge into actual practice as measured by the accuracy of GCS scoring. Conclusion: This study suggests that new educational strategies should be developed for the Vietnamese nurses to improve their performance on accurate GCS scoring based on theoretical knowledge.

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부분 AUC와 최적분류점들 (Partial AUC and optimal thresholds)

  • 홍종선;조현수
    • 응용통계연구
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    • 제32권2호
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    • pp.187-198
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    • 2019
  • ROC와 CAP 곡선을 이용하여 다양한 정확도 측도를 바탕으로 최적분류점을 추정하는 많은 연구가 있다. 본 연구에서는 ROC와 CAP 곡선의 특정한 부분 면적을 나타내는 대안적인 통계량을 제안한다. 새롭게 정의된 부분 면적을 나타내는 통계량의 미분방정식을 이용하여 ROC와 CAP 함수와의 관계를 살펴보고, 다음으로는 ROC와 CAP 곡선에 대한 다양한 정확도 측도들의 조건에서의 최적분류점과의 관계를 유도한다. 혼합분포를 구성하는 두 종류의 분포함수를 다양한 정규분포로 가정하여 최적분류점을 설정하고, 다양한 정확도 측도들의 조건에서의 최적분류점에 대응하는 제1종과 제2종 오류의 크기를 탐색하고 토론한다.

LPC에 의한 화자 식별 (On using the LPC parameter for Speaker Identification)

  • 조병모
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1987년도 학술발표회 논문집
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    • pp.82-85
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    • 1987
  • Preliminary results of using the LPC parameter for text-independent speaker identification problem are presented. The idetification process includes log likelihood ratio for distance measure and dynamic programming for time normalization. To generate the data base for experiments, ten times. Experimental results show 99.4% of identification accuracy, incorrect identification were made when the speaker uses a dialect.

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항공기 탑재용 카메라 정렬오차 정의 및 시험방안 연구 (A Study of Alignment Tolerance's Definition and Test Method for Airborne Camera)

  • 송대범;윤용은;이행복
    • 한국군사과학기술학회지
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    • 제16권2호
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    • pp.154-159
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    • 2013
  • Alignment tolerance for EO/IR airborne camera using common optic is an important factor in stabilization accuracy and geo-pointing accuracy. Before airborne camera is mounted on the aircraft, defining alignment tolerance and verification of it is essential in production as well as research and development. In this paper we establish basic concept on the definition and elements of alignment tolerance for airborne camera and propose how to measure each of those elements. Components and the measurement sequence of alignment tolerance are as follows: 1) tolerance of alignment between EO and IR LOS. 2) tolerance of sensor alignment. 3) tolerance of position reporting accuracy. 4) tolerance of mount alignment