• Title, Summary, Keyword: error

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Code Construction Methods for Error Discriminating and Unidirectional Error Control Codes

  • Ahn Tae Nam;Sakaniwa Kohichi;Rao T. R. N.
    • Journal of the military operations research society of Korea
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    • v.15 no.2
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    • pp.56-77
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    • 1989
  • A new concept, namely the error discrimination of a code defined as the capability to not only detect errors from two distinct error sets but also to distinguish between them has been introduced in [SAKA 89a]. Consider $E_+\;and\;E_-$ as the two distinct error sets, namely the positive error set and the negative error set respectively. If a code C is not only capable of detecting any error e in {$E_+,\;E_-$}, but also able to identify the error set to which e belongs then the code is said to be an $E_+\;&\;E_-$ error discriminating code. The error discriminating property enables construction of unidirectional error detecting/correcting codes using asymmetric error control code. We derive here theory for asymmetric t error correcting and d error detecting codes. Furthermore, unidirectional error control code construction methods are introduced using asymmetric error control codes and $E_+\;&\;E_-$ error discriminating codes.

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Error Control Strategy in Error Correction Methods

  • KIM, PHILSU;BU, SUNYOUNG
    • Kyungpook Mathematical Journal
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    • v.55 no.2
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    • pp.301-311
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    • 2015
  • In this paper, we present the error control techniques for the error correction methods (ECM) which is recently developed by P. Kim et al. [8, 9]. We formulate the local truncation error at each time and calculate the approximated solution using the solution and the formulated truncation error at previous time for achieving uniform error bound which enables a long time simulation. Numerical results show that the error controlled ECM provides a clue to have uniform error bound for well conditioned problems [1].

A Study on the Volumetric Error Equation of Coordinate Measuring Machines and their Application (3차원 좌표측정기(CMM)의 오차방정식 유도에 관한 연구)

  • 이응석
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.6
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    • pp.1545-1553
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    • 1995
  • For general geometry of Coordinate Measuring Machine (CMM), volumetric error equation including 21 systematic error components was showed using vector expression. Different types of CMM listed on an international standard (BS 6808) were classified according to their geometry, and the general volumetric error equation was used for the CMMs. Application of volumetric error equation was also introduced, such as position error compensation, error equation of CNC-machine and parametric error analysis, etc.

A Study on the Effect of the Sensor Gain Error in the Precision Measurement of Straightness Error Using Mixed Sequential Two-Probe Method (혼합축차이점법을 이용한 진직도 정밀측정에 있어서 센서 게인오차의 영향에 관한 연구)

  • Jeong, Ji Hun;Oh, Jeong Seok;Kihm, Gyungho;Park, Chun Hong
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.6
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    • pp.607-614
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    • 2013
  • In this study, effect of the sensor gain error is theoretically analyzed and simulated when mixed sequential two-prove method(MTPM) is applied for the precision measurement of straightness error of a linear motion table. According to the theoretical analysis, difference of the gain errors between two displacement sensors increases measurement error dramatically and alignment error of the straightedge is also amplified by the sensor gain difference. On the other hand, if the gain errors of the two sensors are identical, most of error terms are cancelled out and the alignment error doesn't give any influence on the measurement error. Also the measurement error of the straightness error is minimized compared with that of the straightedge's form error owing to close relationship between straightness error and angular motion error of the table in the error terms.

A Study on the Analysis of Error Sources and Error Compensation in Machine Tools (공작기계 오차 요인의 분석 및 보정에 관한 연구)

  • Kim, Ki-Hwan;Youn, Jae-Woong
    • Journal of the Korea Convergence Society
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    • v.8 no.5
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    • pp.185-192
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    • 2017
  • Machine tool errors can be divided into geometric error, thermal deformation error, and machining error. In this study, the influence of each error on the total error and the relative size of each error are quantitatively analyzed in 2D machining. The thermal deformation error and the machining error caused a relatively large error compared to the geometric error, which is directly related to the machining accuracy. In order to eliminate the error factors, the possibility of error compensation was examined by analyzing the measured error profile shape. As a result, about 40 ~ 50% error compensation was achieved for each error factor. Through this study, it is possible to construct a basic data base on machining, and it is expected that it will be able to compensate the machining error from the viewpoint of users.

Error Synthesis Modeling and Compensation Algorithm of a 5-Axis CNC Machine Tool (5축 CNC 공작기계의 오차합성모델링 및 보정 알고리즘)

  • Yang, Seung-Han;Lee, Chul-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.8
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    • pp.122-129
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    • 1999
  • A 5-axis CNC machine tool is more useful compared with a 3-axis machine tool, because the position and the orientation of a tool tip can be controlled simultaneously. Unlike the 3-axis machine tool, the 5-axis machine tool has the volumetric position error and volumetric orientation error due to the quasi-static error of each machine tool joint which is a major source of machined part error. So, the generalized error synthesis model of the 5-axis CNC machine tool was developed to predict and to compensate for the volumetric position error and the volumetric orientation error. It was proposed that a compensation algorithm to correct simultaneously the volumetric position error and the volumetric orientation error of the 5-axis CNC machine by error inverse kinematic.

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Controller Design by Error Shape and Steady-State Error Analysis for a Feed Drive System in CNC Milling Machine (CNC 밀링머신 이송장치의 오차유형 및 정상상태 오차해석에 의한 제어기 설계)

  • Lee Gun-Bok;Gil Hyeong-Gyeun
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.3
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    • pp.52-60
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    • 2005
  • This paper deals with the position control fur a feed drive system in CNC milling machine, which utilizes a modified error signal for the elimination of steady-state error. A linear time-invariant (LTI) system has consistent properties in response to standard test signal inputs. Those also appear in an error curve acquired from the response. From such properties, constructed is an error model for the position control of the feed drive. And then added is the output of the error model to the current error signal. Consequently the resulting proportional control system brings performance improvement in view of the steady-state error. The effectiveness of the proposed scheme is confirmed through simulations and experiments.

Role of Transformational-leadership in the Relationship between Medication Error Management Climate and Error Reporting Intention of Nurse (간호사가 인지한 투약오류관리풍토와 오류보고의도의 관계에서 변혁적 리더십의 역할)

  • Kim, Myoung Soo
    • Korean Journal of Adult Nursing
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    • v.25 no.6
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    • pp.633-643
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    • 2013
  • Purpose: The objective of this study was to identify the moderating and mediating effects of transformational-leadership in the relationship between medication error management climate and error reporting intention. Methods: Participants in this study were 118 nurses from 11 hospitals in Korea. The scales of medication error management climate, transformational-leadership and error reporting intention of nurses were used in this study. Descriptive statistics, t-test, ANOVA, partial Pearson correlation coefficient, and stepwise multiple regression were used for data analysis. Results: Higher transformational leadership group members had higher error management climate (t=3.88~4.64, p<.001) and higher intention to error reporting (t=2.49, p=.014). There were significant positive correlations between subcategories of medication error management climate and transformational leadership (r=.37~.51, p<.001). But error reporting intention was related to the transformational leadership (r=.28 p=.002), two subcategories such as 'learn from error' (r=.26, p=.004) and 'medication error competence' (r=.25, p=.008) of medication error management climate. Transformational-leadership was a moderator and a mediator between medication error management climate and error reporting intention. Conclusion: Based on the results of this study, transformational-leadership promotion training program to construct medication error management climate and to improve error reporting intention should be needed.

Research on the thermal deformation model ins using by regression analysis (회귀분석을 이용한 열변형 오차 모델링에 관한 연구)

  • 김희술;고태조;김선호;김형식;정종운
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • pp.47-52
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    • 2002
  • There are many factors in machine tool error. These are thermal deformation, geometric error, machine's part assembly error, error caused by tool bending. Among them thermal error is 70% of total error of machine tool . Prediction of thermal error is very difficult. because of nonlinear tendency of machine tool deformation. In this study, we tried thermal error prediction by using multi regression analysis.

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The Analysis of Motion Error in Scanning Type XY Stage (스캐닝 방식 XY 스테이지의 운동오차 분석)

  • 황주호;박천홍;이찬홍;김동익;김승우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.1380-1383
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    • 2004
  • The scanning type XY stage is frequently used these days as precision positioning system in equipment for semiconductor or display element. It is requested higher velocity and more precise accuracy for higher productivity and measuring performance. The position accuracy of general stage is primarily affected by the geometric errors caused by parasitic motion of stage, misalignments such as perpendicular error, and thermal expansion of structure. In the case of scanning type stage, H type frame is usually used as base stage which is driven by two actuators such as linear motor. In the point view of scanning process, the stage is used in moving motion. Therefore, dynamic variation is added as significant position error source with other parasitic motion error. Because the scanning axis is driven by two actuators with two position detectors, 2 dimensional position errors have different characteristic compared to general tacked type XY stage. In this study 2D position error of scanning stage is analyzed by 1D heterodyne interferometer calibrator, which can measure 1D linear position error, straightness error, yaw error and pitch error, and perpendicular error. The 2D position error is evaluated by diagonal measurement (ISO230-6). The yaw error and perpendicular error are compensated on the base stage of scanning axis. And, the horizontal straightness error is compensated by cross axis compensation. And, dynamic motion error in scanning motion is analyzed.

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