• Title/Summary/Keyword: Measuring methods

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A Study on Application of Reverse Engineering for Technical Surfaces (기능성곡면의 역공학 적용에 관한 연구)

  • 황종대;정종윤;정윤교
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.319-325
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    • 2002
  • Reverse Engineering is to find CAD model through measured data of a physical model which is not available in CAD model. The measured data are obtained from measuring with Coordinate Measuring Machine or Laser Scanner. This paper introduces efficient methods of reconstruction through the applicating process of the Reverse Engineering with technical surfaces.

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New Metric For Short-Range Uniformity of AMOLEDs

  • Arkhipov, Alexander;Lee, Baek-Woon;Park, Kyong-Tae;Kim, Chi-Woo;Lee, Jin-Seok
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.488-491
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    • 2008
  • The variations of the TFT characteristics in AMOLEDs result in the decrease of the uniformity of the displays. Measurement of the long-range uniformity (LRU) is straightforward. However, there is no method for measuring the short-range uniformity (SRU) yet. Quantifying the SRU is important in evaluating various TFT backplanes and compensation circuits. We propose new methods for measuring SRU.

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Study on Application of Reverse Engineering of Impeller using Polynomial Regression (다항식회귀분석을 통한 임펠러의 역공학 적용에 관한 연구)

  • 윤상환;황종대;정윤교
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1776-1779
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    • 2003
  • This research presents Reverse Engineering of a Impeller. The modeling introduced in this paper adopts polynomial regression that is utilizing approximating technique. The measured data are obtained from measuring with Coordinate Measuring Machine. This paper introduces efficient methods of Reverse Engineering using Polynomial Regression.

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A Study on the Performance Characteristics of Float Type Flow Meter (부자식 유량계의 성능특성에 관한 연구)

  • 김춘식;김경근;이영호
    • Journal of Advanced Marine Engineering and Technology
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    • v.9 no.4
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    • pp.339-347
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    • 1985
  • Precise measurement of flowrate is considered as an important measuring factor in mechanical and chemical experiment. Although there are many methods to measure flowrate, Float type flowmeter is widely used because of its easy attachment to piping and high measuring precision. To design the precise float type flowmeter, much design information such as tapered-tube dimensions, float size, float shape and float material is required. In this paper, fundamental design theory for float type flowmeter according to the given flowrate range is suggested and compensation coefficients of volumetric and weight flowrate for water, R-113 and air are calculated.

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Modeling of functional surface using Polynomial Regression (다항식회귀분석을 이용한 기능성곡면의 모델링)

  • 윤상환;황종대;정윤교
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.10a
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    • pp.376-380
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    • 2002
  • This research presents modeling of a functional surface which is a constructed free-formed surface. The modeling introduced in this paper adopts polynomial regression that is utilizing approximating technique. The measured data are obtained from measuring with Coordinate Measuring Machine. This paper introduces efficient methods of Reverse Engineering using Polynomial Regression.

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Sample Size Determination and Evaluation of Form Errors

  • Chang, Sung Ho;Kim, Sunn Ho
    • Journal of Korean Society for Quality Management
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    • v.22 no.3
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    • pp.85-98
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    • 1994
  • In current coordinate measuring machine practice, there are no commonly accepted sample sizes for estimating form errors which have a statistical confidence. Practically, sample size planning is important for the geometrical tolerance inspection using a coordinate measuring machine. We determine and validate appropriate sample sizes for form error estimation. Also, we develop form error estimation methods with certain confidence levels based on the obtained sample sizes in various form errors: straightness, flatness, circularity, and cylindericity.

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Analytical Methods for Cationic Surfactants Sorbed by Fabrics (직물에 흡착된 양이온계면활성제 정량방법에 관한 연구)

  • 박선경;정혜원
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.3
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    • pp.422-428
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    • 2000
  • At present, analytical methods available for determining the amount of cationic surfactants(DSDMAC) on the fabrics are spectrophotometric method based on formation and extraction of the colored ion pair with anionic dye, radiochemical analysis and HPLC analysis. This study presents new analytical methods based on the formation of cationic surfactant(DSDMAC)-disulfine blue complex on the cotton fabric. Test methods for determining the amount of DSDMAC-disulfine blue complex on the cotton fabrics are measuring the reflectance of the colored fabric and the absorbance of the methanol solution of DSDMAC-disulfine blue complex extracted from dyed cotton fabric. Linear relationships between the K/S value of the fabric treated with DSDMAC followed by disulfine blue and the amount of DSDMAC sorbed by cotton fabric were obtained. Thus, the amount of DSDMAC sorbed by cotton fabric can be determined by K/S value of the fabric. DSDMAC-disulfine blue complex on the cotton fabric was extracted with methanol. The amount of DSDMAC sorbed by cotton fabric was estimated by measuring the absorbance of the methanol solution extracted from dyed cotton fabric.

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The reliability of an easy measuring method for abutment convergence angle with a computer-aided design (CAD) system

  • Seo, Yong-Joon;Kwon, Taek-Ka;Han, Jung-Suk;Lee, Jai-Bong;Kim, Sung-Hun;Yeo, In-Sung
    • The Journal of Advanced Prosthodontics
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    • v.6 no.3
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    • pp.185-193
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    • 2014
  • PURPOSE. The purpose of this study was to evaluate the intra-rater reliability and inter-rater reliability of three different methods using a drawing protractor, a digital protractor after tracing, and a CAD system. MATERIALS AND METHODS. Twenty-four artificial abutments that had been prepared by dental students were used in this study. Three dental students measured the convergence angles by each method three times. Bland-Altman plots were applied to examine the overall reliability by comparing the traditional tracing method with a new method using the CAD system. Intraclass Correlation Coefficients (ICC) evaluated intra-rater reliability and inter-rater reliability. RESULTS. All three methods exhibited high intra-rater and inter-rater reliability (ICC>0.80, P<.05). Measurements with the CAD system showed the highest intra-rater reliability. In addition, it showed improved inter-rater reliability compared with the traditional tracing methods. CONCLUSION. Based on the results of this study, the CAD system may be an easy and reliable tool for measuring the abutment convergence angle.

Introducing an Online Measurement System Using Item Response Theory and Computer Adaptive Testing Methods for Measuring the Physical Activity of Community-Dwelling Frail Older Adults

  • Choi, Bong-sam
    • Physical Therapy Korea
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    • v.26 no.3
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    • pp.106-114
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    • 2019
  • Background: It is difficult to assess whether community-dwelling frail older adults may remain pre-frail status or improve into a robust state without being directly checked by health care professionals. The health information perceived by older adults is considered to be one of best sources of potential concerns in older adult population. An online measurement system combined with item response theory (IRT) and computer adaptive testing (CAT) methods is likely to become a realistic approach to remotely monitor physical activity status of frail older adults. Objects: This article suggests an approach to provide a precise and efficient means of measuring physical activity levels of community-dwelling frail older adults. Methods: Article reviews were reviewed and summarized. Results: In comparison to the classical test theory (CTT), the IRT method is empirically aimed to focus on the psychometric properties of individual test items in lieu of the test as a whole. These properties allow creating a large item pool that can capture the broad range of physical activity levels. The CAT method administers test items by an algorithm that select items matched to the physical activity levels of the older adults. Conclusion: An online measurement system combined with these two methods would allow adequate physical activity measurement that may be useful to remotely monitor the activity level of community-dwelling frail older adults.

Temperature distribution prediction in longitudinal ballastless slab track with various neural network methods

  • Hanlin Liu;Wenhao Yuan;Rui Zhou;Yanliang Du;Jingmang Xu;Rong Chen
    • Smart Structures and Systems
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    • v.32 no.2
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    • pp.83-99
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    • 2023
  • The temperature prediction approaches of three important locations in an operational longitudinal slab track-bridge structure by using three typical neural network methods based on the field measuring platform of four meteorological factors and internal temperature. The measurement experiment of four meteorological factors (e.g., ambient temperature, solar radiation, wind speed, and humidity) temperature in the three locations of the longitudinal slab and base plate of three important locations (e.g., mid-span, beam end, and Wide-Narrow Joint) were conducted, and then their characteristics were analyzed, respectively. Furthermore, temperature prediction effects of three locations under five various meteorological conditions are tested by using three neural network methods, respectively, including the Artificial Neural Network (ANN), the Long Short-Term Memory (LSTM), and the Convolutional Neural Network (CNN). More importantly, the predicted effects of solar radiation in four meteorological factors could be identified with three indicators (e.g., Root Means Square Error, Mean Absolute Error, Correlation Coefficient of R2). In addition, the LSTM method shows the best performance, while the CNN method has the best prediction effect by only considering a single meteorological factor.