• Title/Summary/Keyword: Area Measurement

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The Air Flow Measurement and Prediction of Pressure Loss at Engine Inlet Duct (엔진 입구 덕트에서 공기유량 측정 및 압력손실 예측방법)

  • Lee, Bo-Hwa;Yang, In-Young;Yang, Soo-Seok
    • Aerospace Engineering and Technology
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    • v.6 no.2
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    • pp.29-34
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    • 2007
  • The purpose of this paper was to address the methodology of the air flow measurement using duct mach number that was considered area-weighed average obtained by total pressure and temperature measured at engine inlet duct. Without installing boundary rake, the prediction of air flow measurement was discussed. Actual air flow measurement and pressure value using pressure loss through inlet seal were described to improve the reliability and operability of altitude engine test facility.

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The measurement of partial discharge for preventive diagnosis in power machinery (전력용 기기의 예방진단을 위한 부분방전측정)

  • 김태성;구할본;임장섭;정우성
    • Electrical & Electronic Materials
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    • v.7 no.1
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    • pp.42-48
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    • 1994
  • The preventive diagnosis technique for power system is being highlighted as a research area for deterioration of insulation in machinery because of high-voltage power system. We make efforts to develop not only diagnosis of aging state but also detection of defects in the initial stage from preventive diagnosis technique. Especially, partial discharge is actively studied as a non-destructive diagnosis technique and very useful because partial discharge measurement reduces damage than conventional diagnosis technique. The loaded stress during this test is smaller than that of other diagnosis techniques. But the continuous research for various complicated analysis method is required because partial discharge has very small signals and its signals have complex forms. In this paper, the measurement of partial discharge was investigated and studied on many specimens with void. We made samples having artificial voids and measured partial discharge. In order to use as a practical diagnosis technique, we studied ways of measurement, measured illustrations and types of partial discharge which could be used in order to diagnose defects of power machinery.

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SCRATCH TESTERS ON THE APPLICATION TO THE ADHESION MEASUREMENT OF THIN COATINGS

  • Takeshita, Kyo
    • Journal of the Korean institute of surface engineering
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    • v.29 no.6
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    • pp.691-694
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    • 1996
  • Two models of scratch testers developed recently are applied to the adhesion measurement of thin coatings. In both models the critical load is determined from the frictional irregularity when coated surface is broken in the scratching process. One model is effective for coatings thicker than 1m and the other for thin coatings down to $0.1\mu\textrm{m}$. The mechanism and the measurement principle of these testers are described. High sensitivity and good reproducibility of the measurement are attained primarily by the employment of new detection devices. These testers are even more useful for the quality control and the inspection of commercial products of coatings because only a small area of specimen is required for the test.

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Three-Dimensional Fluid Flow Analysis of Photoacoustic Spectroscopy Cell for Measurement of Automotive Exhaust Gas (자동차 배출가스 측정을 위한 Photoacoustic Spectroscopy Cell의 3차원 유동장 해석)

  • 김현철;박종호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.2
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    • pp.111-118
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    • 2003
  • Recently, environmental damage to urban area becomes serious problem due to the exhaust emissions by increasing the number of vehicle. Especially, exhaust emission from diesel vehicles are blown to be harmful to human health and environment. Photoacoustic Spectroscopy system is very useful technology for simultaneous and continuous measurement of the various components of the automotive exhaust gas. In this study, in order to reduce emission gases from automobile, we tried to develop the measurement system of Photoacoustic Spectroscopy. To improve performance of high sensitive Photoacoustic Spectroscopy system for automotive exhaust emissions, the shape of Photoacoustic Spectroscopy cell was optimized to use the flow analysis. And Exhaust emission data of the 1,500cc gasoline engine was fixed the working fluid. The characteristics of fluid flow for cell were analyzed by various conditions in detail.

Nondestructive Characterization of Materials Using Laser-Generated Ultrasound

  • Park, Sang-Woo;Lee, Joon-Hyun
    • International Journal of Reliability and Applications
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    • v.5 no.1
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    • pp.1-13
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    • 2004
  • It is recently well recognized that the technique for the one-sided stress wave velocity measurement in structural materials provides measurement in structural materials provides valuable information on the state of the material such as quality, uniformity, location of cracked or damaged area. This technique is especially effective to measure velocities of longitudinal and Rayleigh waves when access to only one surface of structure is possible. However, one of problems for one-sided stress wave velocity measurement is to get consistent and reliable source for the generation of elastic wave. In this study, the laser based surface elastic wave was used to provide consistent and reliable source for the generation of elastic wave into the materials. The velocities of creeping wave and Rayleigh wave in materials were measured by the one-sided technique using laser based surface elastic wave. These wave velocities were compared with bulk wave velocities such as longitudinal wave and shear wave velocities to certify accuracy of measurement. In addition, the mechanical properties such as poisson's ratio and specific modulus(E/p) were calculated with the velocities of surface elastic waves.

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Suggestion of Research Direction for Technology Development on Accurate Measurement of Remaining Capacity in Li-ion Batteries (리튬이온 배터리의 정확한 잔량 측정 기술개발을 위한 연구 방향 제안)

  • Joo, KangWo;Lee, YunChul;Ha, JooHwan;Kim, Kwang-sun
    • Journal of the Semiconductor & Display Technology
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    • v.15 no.2
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    • pp.16-19
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    • 2016
  • More efficient use of the battery pack is dependent upon how to measure the remaining capacity of the battery accurately. Among various measurement methods, the basic correction measurement method has still been a hot research topic area to reduce the errors. In this paper, the problems of the existing methods have been investigated and the research direction for measuring more accurate remaining capacity has been suggested by applying the numerical simulations in the future.

A Study on the Precise Measurement of the Performance in the Heating System (발열시스템 열적 성능의 정밀측정에 관한 연구)

  • 최창용;김홍건
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.11 no.6
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    • pp.60-67
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    • 2002
  • A precise measurement of field test was performed to estimate the thermal performance of the forced convection electric air heater by experiment. Air temperature, flow rate and electrical power input were measured with the related measurement sensors, and acquisition methods for the measured data were studied to estimate the thermal performance of the tested air heater effectively. To determine the mean air temperature at the flow cross-section, measuring positions were chosen by considering the flow velocity profile and the equally divided cross-sectional area. From the experimental results, thermal efficiency was obtained accurately as an indication of the tested heating system performance.

Next Generation Fiber Length Measurement

  • Tiikkaja, Esa;Sopenlehto, Taina
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.32 no.5
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    • pp.54-59
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    • 2000
  • The next generation fibre size analyser has been developed in Kajaani based on over 15 years experience in fibre measurement. This new FiberLab-analyser can measure fibre length both along the fibre centre line and as projected. The cross-sectional measurements of fibre are in principle similar to the earlier version FiberLab. Measured data are generally displayed in distributions. Some new calculations have been added, for example the fibres cross sectional area and fibre volume index both available as distributions as well. The performance of the FiberLab measurement is verified against the manual microscopic testing. These tests show that the new image analysis-based measurement well matches with the manual methods.

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A Study on the Development of Creative Management Measurement Systems (창조경영 수준 진단 시스템 개발에 관한 연구)

  • Kim, Sang Soo;Kim, Young Cheon
    • Knowledge Management Research
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    • v.14 no.2
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    • pp.1-24
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    • 2013
  • With rapid changes in technology and global competition, the success of many companies has become progressively more dependent on their ability to bring unique products, services, and business models to market. Therefore, many companies have tried to use creativity to all over the management activities and the concept of creative management is emerging. Creative management is a new but rapidly growing research area. But there have been few studies on this topic. In this paper, we developed the framework for measuring Creative Management levels of a company. The contribution of this paper is the following. First, we suggested a systematic measurement tool for creative management level focused on the management capability, business process and outcomes. Secondly, the creative measurement system developed in this paper can support companies to implement creative management as a guideline for adopting creative management.

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The Development of a Stress Measurement Tool for School Children in Chon-buk Area (초등학생이 일상생활 중 경험하는 스트레스 측정 도구 개발)

  • Chung, Seung Hee;Chung, Young Suk
    • Journal of the Korean Society of School Health
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    • v.11 no.2
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    • pp.279-284
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    • 1998
  • The purpose of this study was to propose the baseline data for the development of a stress measurement tool for primary school students. The data were collected from 650 students from four primary schools in the Chon-buk area from April 1 to May 30, 1995. Through a pretest and literature review a questionaire was designed with 57 stressors experienced by school children in daily life. Reliability of the tool was tested by a Cronbach's alpha and the result was ${\alpha}=.9137$. Factor analysis was applied to organize the 57 items together. As the result, 8 factors were obtained and these factors explained 40% of the variance. The 8 factors were: 1) Life events related to family, 2) Conflict related to friend & senior or junior, 3) Educational attitude of parents, 4) Own personality, 5) School life events, 6) Scolding by teacher and parent, 7) Conflict with interpersonal relationship, and 8) Change of situation.

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