• Title/Summary/Keyword: method of measurement

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A Study on the Measurement Technique of the Grounding Mesh Resistance by Field Measurements (현장실측에 의한 메시(Mesh)접지저항 출정기법 연구)

  • 한기붕;김삼수;정세중;이상익
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.426-429
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    • 1999
  • In this paper, we have provided the measurement technique of the grounding mesh resistance by field measurements. The standard of measurement is specified in the IEEE Std 81.2-1991 and JEAC 5001-1988, which is the the fall-of-potential method by test-current injection, but this method is difficult to apply at field, where is small around a electric power substation of domestic. For the convenient measurement method, space of assistant probe and quantity of test-current injection are changed step for step. As the result, ' the proposed measurement technique of grounding mesh resistance is that the space of current and potential probes must be fixed at 150rn from a grounding mesh, the test-current injection has to keep 5A or more.

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Measurement of Low-Frequency Vibrations of Structures Using the Image Processing Method (영상 처리 방법을 이용한 구조물의 저주파수 진동 계측)

  • Kim, Ki-Young;Kwak, Moon- K.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.503-507
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    • 2004
  • This paper is concerned with the measurement of low-frequency vibrations of structures using the image processing method. To measure the vibrations visually, the measurement system consists of a camera, an image grabber board, and a computer. The specific target installed on the structure is used to calculate the vibration of structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the size of image. In this paper, we discuss the methodology for the vibration measurement using the image processing method. The method enables us to measure the displacement directly without any contact. The resolution of the vibration measurement can be refined but limited to the sub centimeter displacement.

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The Method for Measuring the Initial Stage of Emotion in Use Context (제품 사용 환경의 사용자 초기 감성 측정 방법에 관한 연구)

  • Lee, Jae-Hwa;Lee, Kun-Pyo
    • Science of Emotion and Sensibility
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    • v.13 no.1
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    • pp.111-120
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    • 2010
  • Initial stage of emotion has a great influence on building up product image and impression. Because of its influencing effects, measuring initial stage of emotion has potential to be a key factor for designers and marketers to achieve a distinct product concept. While many researchers have studied this topic with the emotion measurement method in product use stage, there are very few cases specialized in the initial stage of emotion. Even though present emotion measurement methods have difficulties to derive accurate user's initial stage of emotion, most case of initial emotion study applies these defective methods. The purpose of this study is to develop initial stage of emotion measurement method and apply this method to real product context. In the design of the initial stage of emotion measurement method, noticeable characteristics of initial stage of emotion were explored and initial emotion measurement framework was presented. Based on this framework, Initial Emotion Measurement System(IEMS) was suggested. This method collects user's eye movement, behavior and verbal data accurately and objectively.

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Blood pressure measurements and hypertension in infants, children, and adolescents: from the postmercury to mobile devices

  • Lim, Seon Hee;Kim, Seong Heon
    • Clinical and Experimental Pediatrics
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    • v.65 no.2
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    • pp.73-80
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    • 2022
  • A mercury sphygmomanometer (MS) has been the gold standard for pediatric blood pressure (BP) measurements, and diagnosing hypertension is critical. However, because of environmental issues, other alternatives are needed. Noninvasive BP measurement devices are largely divided into auscultatory and oscillometric types. The aneroid sphygmomanometer, the currently used auscultatory method, is inferior to MS in terms of limitations such as validation and regular calibration and difficult to apply to infants, in whom Korotkoff sounds are not audible. The oscillometric method uses an automatic device that eliminates errors caused by human observers and has the advantage of being easy to use; however, owing to its measurement accuracy issues, the development of an international validation protocol for children is important. The hybrid method, which combines the auscultatory and electronic methods, solves some of these problems by eliminating the observer bias of terminal digit preference while maintaining measurement accuracy; however, the auscultatory method remains limited. As the age-related characteristics of the pediatric group are heterogeneous, it is necessary to reconsider the appropriate BP measurement method suitable for this indication. In addition, the mobile application-based BP measurement market is growing rapidly with the development of smartphone applications. Although more research is still needed on their accuracy, many experts expect that mobile application-based BP measurement will effectively reduce medical costs due to increased ease of access and early BP management.

A study on improvement of convergent measurement performance of color display tube using photo sensors (포토 센서를 이용한 브라운관의 컨버젼스 측정 성능 향상에 관한 연구)

  • ;;Zeungnam Bien
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.3
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    • pp.93-101
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    • 1998
  • In Integrated Tube Components(ITC) process in themanufacturing of color display tube, we describe the necessity of the convergence measurement method using photo sensors. Compared with methods using 1D or 2D cameras, its characteristics is to use of moving image patterns and fixed sensors. This measurement method is formulated as the measurement problem of the phase difference in phase changing periodic signals. The convergence measurement system using photo sensors, for the good performance, must have a small standard deviation for the repetitive measurement in the same condition and a fast measurement time for thecovergence change. By above two conditions, we proposed the real time measurement algorithm of the pahse difference using fundametal and harmonic in phase changing periodic signals. And, the proposed algorithm is applied to the convergence measurement system.

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A Study on the Measurement Method of Test Waveform for System-level HEMP Immunity Test (체계 수준 HEMP 내성 시험을 위한 시험파형 계측 기법 연구)

  • Yeo, Saedong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.22 no.2
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    • pp.233-240
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    • 2019
  • High-altitude ElectroMagnetic Pulse(HEMP) is a high-power electromagnetic pulse caused by nuclear explosions at altitudes above 30 km. This pulse can cause serious damage to the electrical/electronic device. Therefore, there are a lot of studies on the effects of HEMP in the literature. When conducting studies on the effects of HEMP, it is essential to measure the simulated HEMP. Depending on the need for measurement, this paper focuses on the HEMP measurement method. This paper proposes a measurement method using frequency domain compensation to extract the correct waveform and solves the offset problem more efficiently than the conventional methods. The proposed method is verified by experiment using HEMP simulator and measurement system in ADD.

Development of Wireless Earphone Playback Time Measurement Method and Report Form (무선이어폰 재생 시간 측정 방법 및 보고 양식 개발)

  • Han, Mun-Hwan;Jeong, In-Ho
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.2_2
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    • pp.299-307
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    • 2022
  • Wireless earphones, along with smart devices, are the most sought-after products by consumers. Compared to general earphones, wireless earphones do not have twisted wires and are easy to use, so various types of products are currently on the market. However, information on quality is somewhat lacking, so consumers tend to purchase products according to brand awareness, and manufacturers are delivering information to consumers using different standards for each product because there is no standard for quality control. In particular, the playback time of wireless earphones is a factor that directly affects consumers' purchases, so a standard measurement method is needed to properly measure it. In this paper, we present a method for measuring the audio playback time of wireless earphones derived from domestic wireless earphone status survey, commercial product measurement test, and research analysis, and a developed standard measurement method. In addition, this paper proposes a measurement result reporting format to provide accurate information to consumers and induce a fair competitive environment for each product to manufacturers.

The Study of the Accuracy of Acereage (측정법(測定法)에 따른 면적측정(面積測定)의 정도(精度))

  • Kim, Kap D.
    • Journal of Korean Society of Forest Science
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    • v.6 no.1
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    • pp.24-26
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    • 1967
  • 1. The purpose of this experiment was to compose the precision of dot grid method and transects method with that of pianimeter method in area measurement. 2. The following conclusions were obtained through study on precision of area measurement of 20 plots. 3. The percentage error of each method was none significant in comparision with planimeter method. 4. The dot grid method gave 0.2% of overestimated value and the transects method 0.67% of underestimated value. 5. Accordingly, the dot grid method gave the better result than the transects method. 6. The transects method had small errors at the plots larger than 30ha. while it had big errors at plots smaller than 30ha. Therefore, it can be said that the transects method is suitable for area measurement of plots larger than 30 hectares.

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Utilization of Light Microscopy and FFT for MFA Measurement from Unstained Sections of Red Pine (Pinus Densiflora)

  • Kwon, Ohkyung;Lee, Mi-Rim;Eom, Chang-Deuk
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.5
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    • pp.399-405
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    • 2013
  • This study demonstrates the utilization of light microscopy and Fast Fourier Transform-Peak Finding (FPF) method for microfibril angle (MFA) measurement from unstained sections of red pine (Pinus densiflora). To obtain an image with optimal contrast and resolution for MFA measurement, effects of numerical aperture (NA) of condenser lens and color filters were investigated. About 60% of NA of the maximum condenser NA produced an image with optimal contrast, but a color filter with short wavelength range (DAPI) created images with improved resolution. Manual angle measurement and the FPF method were applied to the image with optimal contrast for MFA measurement. The experimental results from the FPF method were considered to be more repeatable and less subjective than those from the manual angle measurement.

HFPD Characteristic Analysis of Simulated Transformer According To Applied Voltage (인가전압에 따른 모의변압기의 HFPD 특성분석)

  • Kim, Duck-Keun;Im, Young-Sham;Lim, Jang-Seob;Moon, Chae-Joo;Lee, Jin
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1957-1959
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    • 2000
  • The PD measurement method is very useful to detect insulation degradation. Recently, the HFPD(High Frequency Partial Discharge) measurement testing is widely used in partial discharge measurement of HV machines because HFPD measurement testing receives less influence of external noise and has a merit of good sensitivity. Therefore it is very useful method compare to previous conventional PD testing method and effective diagnosis method in power transformer that requires in-service diagnosis. But partial discharges have very complex characteristics of discharge pattern so it is required continuous research to development of precise analysis method. In this study, simulated transformer is manufactured and HFPD occurred from simulated transformer is measured with broad band antenna and active-line RF measurement system in real time, the degradation grade of transformer is analyzed through produced patterns in simulated transformer according to applied voltages. Also the PD pattern which was measured with EMC analyzer and RF measurement system is compared.

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