• Title/Summary/Keyword: Precise measurement

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Development of Motor, Encoder Evaluation System using High Performance DSP (고성능 DSP를 이용한 모터, 엔코더 성능평가 시스템 개발)

  • Jang, Mun-Suck;Shim, Jae-Hong;Lee, Enug-Hyuk;Choi, Sang-Bang
    • Journal of the Semiconductor & Display Technology
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    • v.8 no.4
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    • pp.77-82
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    • 2009
  • In robot operation, a motor with multi-degree of freedom motion control and an encoder for motor control are needed. To perform precise motion, location, and velocity control, the operation of motor and encoder with superior performance is important. In this paper, we studied performance evaluation system that can evaluate the performance of motor and encoder. The performance of motor and encoder can be evaluated in terms of disconnection check, signal variation count, and U, V, W signal check. Disconnection check verifies signal connection between a motor and an encoder, signal variation check verifies A, B signal by counting the number of signal A, B when a motor revolves, and U, V, W signal check verifies operating direction of a motor. The result is shown at graphic LCD integrated in system, and can be checked in PC with PC communication.

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A Study on Sizing System for Mail-Order Clothing (통신판매의류의 치수에 대한 조사 연구)

  • 박경화;천종숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.1
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    • pp.43-53
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    • 1996
  • This study was initiated to investigate (1) the current sizing system for mail-order clothing, (2) consumers' preference for sizing systems, and (3) consumers' satisfaction with garment size. The apparel items and the sizes available at various mail-order companies in Korea were also reviewed. This investigation of consumers' preferences for various size description systems includes a survey of 410 men and women who had purchased garments by mail-order. The data were analyzed by Statistical Analysis System/pc. The major results are as follows; 1. The sizing system of mail-order clothing was different by garment items. The number of apparel sizes available for mail-order purchasing was three or less. The most mail∼order garments were labeled by the numerical size codes of body girth nleasurements or letter code (S, M, L). 2. The size description system most prefered by female subjects(N : 360) was the numerical size code of a body measurement(55.4%). The combination of bust-hips-height measurements size codes were prefered by 13.3% . The pictogram was least premiered by the subjects. 3. The apparel items that subjects wanted to buy using mail-order were underwear, home -weat and night-wear. The heavy users of mail-order purchasing, however, also wanted to purchase expensive garments requiring precise fit. The subjects aged from 20's to 80's wanted to purchase childern's wear by mail. 4. The desire for diversity of garment item and size of mail-order apparel was relatively high. The subjets also wanted to purchase special size garments by mail-order, e. g., garment sizes for full or tall figure.

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Mathematics in the Joseon farmland tax systems (조선(朝鮮)의 전제법(田制法)과 산학(算學))

  • Hong, Sung Sa;Hong, Young Hee;Kim, Chang Il
    • Journal for History of Mathematics
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    • v.28 no.2
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    • pp.65-72
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    • 2015
  • The Joseon dynasty (1392-1910) is basically an agricultural country and therefore, the main source of her national revenue is the farmland tax. Thus the farmland tax system becomes the most important state affair. The 4th king Sejong establishes an office for a new law of the tax in 1443 and adopts the farmland tax system in 1444 which is legalized in Gyeongguk Daejeon (1469), the complete code of law of the dynasty. The law was amended in the 19th king Sukjong era. Jo Tae-gu mentioned the new system in his book Juseo Gwan-gyeon (1718) which is also included in Sok Daejeon (1744). Investigating the mathematical structures of the two systems, we show that the systems involve various aspects of mathematics and that the systems are the most precise applications of mathematics in the Joseon dynasty.

Estimation of Roughness Coefficient Using a Representative Grain Diameter for Han Stream in Jeju Island (한천의 대표입경을 이용한 조도계수 산정)

  • Lee, Jun-Ho;Yang, Sung-Kee;Kim, Dong-Su
    • Journal of Environmental Science International
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    • v.22 no.5
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    • pp.563-570
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    • 2013
  • Roughness coefficient was computed for review of applicability based on measurement of the representative grain diameter reflecting channel characteristics of Han Stream. After field survey, collection of bed material, and grain analysis on the collected bed material, roughness coefficient was computed using representative grain and existing empirical equation for roughness coefficient. Value of roughness coefficient calculated using equation by Meyer-Peter and Muller (1948) was 0.0417 for upstream, 0.0432 for midstream, and 0.0493 for downstream. As a result of comparing the computed roughness coefficient to other empirical equations for review of applicability, the coefficient was larger in Strickler (1923) equation by 0.006. Smaller coefficient was shown by Planning Report for River Improvement Works. Equation by Garde and Raju (1978) was larger by 0.004, and equations by Lane and Carlson (1953) and by Meyer-Peter and Muller (1948) were larger by 0.001. Such precise roughness coefficient is extremely important when computing the amount of flood in rivers to prevent destruction of downstream embankments and property damages from flooding. Since roughness coefficient is a factor determined by complicated elements and differs according to time and space, continued management of roughness coefficient in rivers and streams is deemed necessary.

Size Specifications of Females Aged between 7 and 18 for 3D Body Model Development (여자 7-18세 3D 모델을 위한 인체 사이즈 스펙 개발)

  • Choi, Young Lim
    • Fashion & Textile Research Journal
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    • v.15 no.2
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    • pp.247-255
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    • 2013
  • This study develops size sections and specifications for females 7-18 years old. The specifications will contribute to the development of precise virtual models that represent basic data for the size alteration of 3D virtual models. A total of 33 items from the $5^{th}$ Size Korea data set were adopted and analyzed. Two representative factors (Obesity and Height Factors) were identified through a factor analysis of the 33 items. Waist circumference and stature were selected as representative variables for Obesity and Height Factors, respectively, and conducted cross tabulations between waist circumference and height for the age groups of 7-12 and 13-18 year-olds. Size sections were developed for the development of 3D models based on the results. A regression analysis then developed size specifications for each section with independent variables of waist circumference and height as well as dependent variables of reference body size. Subsequently, Obesity Factors were better explained by waist circumference and Height Factors were better explained by stature. Finally, size specifications for each section were developed.

A Study on the Improvement of Accuracy of Close-Range Photogrammetry Analysis by Using Non-metric Camera (비측량용(非測量用) 사진기(寫眞機)에 의(依)한 근접사진(近接寫眞) 해석(解析)의 정확도(正確度) 향상(向上)에 관(關)한 연구(研究))

  • Kang, Joon Mook;Oh, Won Jin;Han, Seung Hee
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.2
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    • pp.151-159
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    • 1992
  • In close-range photogrammetry, to employ non-metric camera especially for the purpose of precise measurement, systematic errors must, first of all, be corrected as they have a great influence on accuracies of results. For it, fiducial marks was built in non-metric camera and the factors such as PPS, PPA, EFL, CFL, and radial lens distortion coefficients for each quadrant were calibrated through collimator test. Also, the coefficients of both radial and tangential lens distortion were calibrated from analytical plumb line method and therefore main systematic errors could be effectively corrected. Using the calibrated non-metric camera, close-range photogrammetry could be successfully accomplished and accuracies could be improved sharply.

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Development of Auto-Correction Monitoring System for Stud Bolts (스터드 볼트 자동 교정 통합 모니터링 시스템에 관한 연구)

  • Yun, Sung-Un;Kim, Jae-Yeol;Kang, Hyung-Seon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.1
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    • pp.130-134
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    • 2015
  • The automobile industry is ubiquitous and involved in the handling of metal, machines, electricity, electron, and chemistry including the products of many types of processes. In the process of installing engines as a part of the car assembly line, the measurement and correction of the position of the stud bolts consumes a great deal of time. Additionally, defective parts must be manually removed. In the process of engine installation, the speed of the operation, related to the economics of vehicle assembly, is dependent upon measuring the precise position of the stud bolt, reducing the length of correction time, and increasing the working rate. This paper deals with securing the economic feasibility of the manufacturing process, increasing the safety by removing risk factors in the working area, and improving and equalizing the quality by developing an automatic system for the process involving a stud bolt.

Characterization of Microfluidic Channels using DVD Pick-up Fluorescent Scanner (광 픽업 방식 형광스캐너를 이용한 미소유체 특성 분석)

  • Yim, Vit;Kim, Jae-Hyun;Lee, Seung-Yop;Park, Jung-Yul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.12
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    • pp.1102-1106
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    • 2008
  • Microfluidics deals with the behavior, precise control and manipulation of fluids at a micro scale. It has become increasingly prevalent in various applications such as biomedical applications (diagnostics, therapeutics, and cell/tissue engineering), inkjet head, and fuel cells etc. The issue of inspection and characterization of microfluidics has emerged as a major consideration in design, fabrication, and detection of microfluidic devices. In this paper, we characterize a diffusion based mixing in Y-microchannel using a fluorescent optical scanner based on a DVD pick-up module, which is widely used in optical storages. Using fluorescent dye, we measure the fluorescent intensity that represents the mixing patterns in Y-microchannel. We also compare these experimental results with computational fluid dynamics (CFD) simulation ones. It is shown that the proposed optical scanner can be used as an alternative measurement system with high performance and cost-effectiveness, compared to conventional optical tools such as epifluorescent microscopes using high resolution CCD camera and confocal microscopes with photomultiplier (PMT) detectors.

A Method for Slow Component Velocity Measurement of Nystagmus Eye Movements using RLSM (RLSM을 이용한 안구운동의 저속도 측정방법에 대한 연구)

  • Kim Gyu-Gyeom;Ko Jong-Sun;Park Byung-Rim
    • Proceedings of the KIPE Conference
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    • 2002.07a
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    • pp.455-458
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    • 2002
  • A control of the body posture and movement is maintained by the vestibular system, vision, and proprioceptors. Especially, vestibular system has a very important function that controls the eye movement through vestibuloocular reflex and contraction of skeletal muscles through vestibulospinal reflex. However, postural disturbance caused by loss of vestibular function results in nausea, vomiting, vertigo and loss of craving for life. Lose of vestibular function leads to abnormal reflex of eye movements named nystagmus. Analysis of the nystagmus is needed to diagnose the vertigo, which is performed by means of electronystagmography (ENG). The purpose of this study is to develop a computerized system for data processing and an algorithm for the automatic evaluation of the slow component velocity (SCV) of nystagmus Induced by optokinetic(OKN) stimulation system. A new algorithm using recursive least square method (RLSM) to detect SCV of nystagmus is suggested in this paper. This method allows a fast and precise evaluation of the nystagmus, through artifact rejection techniques. The results are depicted in this paper.

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Time of Fight Resonace Investigation of Amorphous Selenium Films (비정질 셀레늄 필름의 공명 비행시간 조사)

  • Park, J.K.;Park, S.K.;Lee, D.G.;Choi, J.Y.;Ahn, S.H.;Eun, C.K.;Nam, S.H.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.501-504
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    • 2001
  • We used time-of-flight method to analyze transport properties of charge carrier which is produced by X-ray exposure. It is the research of charge transport and specific property of trap that is performed in direct digital x-ray image receptor. But the results shows us different measurement value of electron and charge drift mobility and it is difficult to precise analysis about charge transport properties and trap mechanism. We measured transit time and drift mobility of charge carriers using time-of-flight method to evaluate the correlation of a-Se thickness change and electric field. We made a testing glass with a-Se of 400 ${\mu}m$ thickness on coming glass using thermoevaporation method and built Au electrode with 300nm, $2{\varphi}$ on both sides of a-Se, As a result of this experiment, electron and hole transit time was each $229.17{\mu}s$ and $8.73{\mu}s$ at $10V/{\mu}m$ electric field and Drift mobility was each $0.00174 cm^{2}/V{\cdot}s$, $0.04584cm^{2}/V{\cdot}s$.

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