• Title/Summary/Keyword: Near-field Measurement

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Comparison Research between Lighting Based on luminance and Illuminance through Measuring Tunnel Lighting (터널조명 측정을 통한 조도와 휘도기반의 조명 비교 연구)

  • Lee, Mi-Ae;Han, Seung-Hun;Kim, Yeon-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.11
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    • pp.14-19
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    • 2013
  • Tunnel lighting design and operation are both regulated based on luminance in and out of Korea these days. However, domestic tunnel lighting is operated by internal lighting depending on external brightness by using an illuminometer applying the conversion factor on luminance. The purpose of tunnel lighting is to alleviate the visual shock occurring from the rapid change from external brightness to internal brightness when entering a tunnel. However, when looking at the tunnels operated based on an illuminometer, it is not a system where the driver can measure the brightness within his or her viewing angle when entering the tunnel. It is general to install and operate the illuminometer on the roof of an administrative office near the tunnel; however, this method is not structured to connect with the internal lighting by checking the brightness of the viewing scope of the driver, thus is not structured to properly apply the viewing conditions of the driver. Rather, it should be in a method for extracting the luminance value within the viewing scope of the driver pursuant to tunnel lighting standards and in connection with internal lighting. This research seeks to find the difference between operations based on luminance and operations based on intensity of Illuminance in road tunnels through field measuring, and to suggest the necessity of operating based on luminance with the resulting value.

Evaluation of the CALPUFF Model Using Improved Meteorological Fields in Complex Terrain of East Sea Coast (동해안의 복잡지형에서 기상장 개선에 따른 CALPUFF 모델의 평가)

  • Lee, Chong-Bum;Kim, Jea-Chul
    • Journal of Korean Society for Atmospheric Environment
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    • v.25 no.1
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    • pp.15-25
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    • 2009
  • Donghae city is one of the most representative cement industrial city in Korea. The area is faced with the East Sea to the East and with high montane region of Tae-Back mountain range to the West. Many pollutant sources of air pollution are located near the coast, but the largest point sources of the region are located at the bottom of the mountain area in Donghae city. The local wind is highly affected by local topography and plays an important role in transport and dispersion of contaminants from the pollution sources. This study was designed to evaluate enhancement of MM5 predictions by using Four Dimensional Data Assimilation (FDDA), the SONDE data and the national meteorological station, data only. The alternative meteorological fields predicted with and without FDDA were used to simulate spatial and temporal variations of NOx in combined with Atmospheric Dispersion Models (CALPUFF). For the modeling domain, the alternative meteorological fields with 1.1 km spatial resolution were interpolated to the CALMET with 0.5 km resolution. The vertical layers set to have 35 and 12 layers for MM5 and CALPUFF, respectively. MM5 with the FDDA did not resulted in significant improvement of meteorological field prediction in Donghae region, which is primarily because of complex geography and wind scheme. The result of CALPUFF, however, showed reduction of uncertainty errors by using the interpolation scheme of the actual measurement data.

Analysis of Flow Character and Gas Measurement from Final Cover Soil of sanitary Landfill (쓰레기 매립지 최종 복토층에서 가스 측정방법과 유출특성 해석)

  • 이해승
    • Journal of Korea Soil Environment Society
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    • v.3 no.3
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    • pp.75-86
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    • 1998
  • This paper is going to show the way we can sample the landfill gases flowing out to the air through final cover soil by using an closed chamber in the field for a short time. In addition, we came to the following results through the application of model with actual measurements. 1) Analyzing changes of concentration in the chamber(H: 10-30cm) every 5 minutes, considering analysis time of gas chromatograph for an half hour. 2) The proportion of $CE_4$to $CO_2$changes rapidly near the surface of final cover soil by the influence of methane oxidation reaction. 3) When flux of landfill gas is F=$10^{-5}$mol/$\textrm{m}^2$.s), methane oxidation reaction has an influence on composition of gases, however there is little influence when F=$10^{-6}$ mol/($\textrm{m}^2$.s).

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A Study on Technique of Navigation with Power-Reflected of the Walker in the Indoor Environment

  • Kim, Min-Sik;Kwon, Hyouk-Gil;Ryu, Je-Goon;Shim, Hyeon-Min;Lee, Eung-Hyuk;Shim, Jea-Hong;Lee, Sang-Moo
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.957-962
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    • 2005
  • Today, the elderly is increasing gradually in the Republic of Korea society and this problem will be more serious in the near future. Therefore, engineering support for aged people is required. We are establishing a new field of healthcare engineering for elderly people and aiming to support for aged people and disabled people using adaptive control and instrument technology. In this paper, the goal is to implement the shared control of a robot mobility aid for the elderly. As using this type of assistive technology to be useful by its intended user community, it supports elderly people and handicapped people to live independently in their private homes. The interface transforms the force applied by the user into the robot's motion. Devices like buttons, joysticks, and levers already exist for relaying user input; however, they require hand displacement that would loosen or otherwise release the user's hold. Such interfaces make operation very difficult and potentially unsafe. Therefore, we propose a shared control system. It's safe more than joysticks and buttons. The shared control is a means of registering the user's intention through physical interaction. It's an important component in the development of robotic elderly assistant. The concept of shared control describes a system which is two or more independent control systems. We are using that the three component blocks consist of pressure sensor (flexible force sensor), circuit of measurement and transfer function. Experimental trials of this paper have been tested at the indoor environment. The robot is able to know the user intended direction through haptic device were logged along with the robot's force sensor.

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Design of Total RMS(Radiation Monitoring System) for nuclear and nuclear medicine (원자력 및 핵의학 분야용 Total RMS (Radiation Monitoring System)의 설계)

  • Ko, Tae-Young;Lee, Joo-Hyun;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.21 no.2
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    • pp.158-161
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    • 2017
  • In this paper, we propose Total RMS(Radiation Monitoring System) for nuclear and nuclear medicine. The proposed system can expand and control Stack Monitor, Area Monitor, and Water(Liquid) Monitor into one system, and can monitor the signals measured by each radiation detector in an integrated manner. The proposed system consists of a sensor module that detects the radiation, a display unit that displays the radiation dose near the radiation detection location, an alarm unit that reports the alarm when the detected radiation dose reaches the danger level, A Main Hub for collecting and storing the contents to the remote monitoring system, and an RMS Monitoring Unit for clearly displaying the measured radiation dose at the remote site. In order to evaluate the performance of Total RMS for the proposed nuclear and nuclear medicine field, it is confirmed that the measurement uncertainty is less than 8.5% and it operates normally within ${\pm}15%$ of the international standard.

Design of Various WBAN Antennas Considering for the Location on a Human Body (인체 상 위치를 고려한 다양한 WBAN 안테나 설계)

  • Tak, Jinpil;Choi, Jaehoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.11
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    • pp.1095-1103
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    • 2014
  • WBAN has received great attention recently due to its versatile applicability. In this paper, antennas suitable for WBAN communication depending on the locations of mobile devices and the manufacturing of a human equivalent phantom are introduced. The effect of the body on the communication performance is largely dependent on the locations of devices. Specifically, the radiation and return loss characteristics of the antenna are greatly influenced by the characteristics of a medium existing in the near-field of an antenna. Thus, the proper WBAN antenna design is important in establishing a successful communication link between the transceivers. To consider the effect of the body on the antenna performance, the human equivalent phantom is also important factor in the WBAN antenna design and measurement. In introduction, categorization of the WBAN communication channel is introduced and antenna characteristics required for each communication channel are described. In the main subject section, several WBAN antenna design examples along with the implementation of the human equivalent phantom are discussed. In conclusion, the factors, which have to be considered in the design process, and future research are mentioned.

A Study on Preventive Diagnosis of the Pole Transformer by Gas Analysis -Measurement of Aging of Insulating Oil by UV-Visible Spectrophotometric Method- (개스분석에 의한 주상변압기의 예방진단에 관한 연구 -자외-가시선 흡수분광광도법에 의한 절연유의 열화도 측정-)

  • 곽희로;남영우;윤영자;남궁미옥;이동준
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.10 no.5
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    • pp.94-100
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    • 1996
  • Criteria for insulating oil condition of pole transformer were suggested by applying the UV-Visible spectrophotometric method. Aging of insulating oil caused the change in absorbances of oil as well as the deterioration of electrical properties of oil. By comparing the electrical properties such as tan$\delta$ and dielectric breakdown voltage with the UV-Visible absorbances of oil, following criteria for absorbance values determining oil condition were established, fair condition is below 0.580, need attention is 0.580-0.900 and poor condition is above 0.900. This W-Visible spectrophotometric method may be applied in aging analysis of oil and expected to replace the current visual method. It is necessary to develop cheap, light and portable UV-Visible spectrophotometer in near future for field application.

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An Experimental Study of Radiated So from Elastic Thin Plate in a Turbulent Boundary Layer (난류 유동장 내에 놓인 탄성을 갖는 박판의 방사소음에 대한 실험적 연구)

  • Lee, Seung-Bae;Gwon, O-Seop;Lee, Chang-Jun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.10
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    • pp.1327-1336
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    • 2001
  • The structural modes driven by the low wave-number components of smooth elastic wall pressure provide a relatively weak coupling between the flow and the wall motion. If the elastic thin plate has any resonant mode whose wave-number of resonance coincides with $\omega$/U$\sub$c/, the power will be transmitted to those modes of vibration by the flows. We examine the problem in which the elastic thin plate is subject to pressure fluctuations under turbulent boundary layer. Measurements are presented of the frequency spectra of the near- and far-field pressures and radiated sound contributed by the various wave modes of the thin elastic plate. Dispersion equation for wave motions of elastic plate is used to investigate the effect of bending waves of relatively low wave number on radiated sound. The low wave-number motion of elastic plate is observed to have much less influence on the low-frequency energy of wall pressure fluctuations than that of the rediated sound. High amplitude events of the wall pressure are observed to weakly couple with high-frequency energy of radiated sound for case of low tension applied to the plate. The sound source localization is applied to the measurement of radiated sound by using acoustic mirror system.

Velocity profile measurement of supersonic boundary layer over a flat plate using the PIV technique (PIV 기법을 이용한 초음속 평판 경계층의 속도 분포 측정)

  • Lee, Hyuk;Kim, Young Ju;Byun, Yung Hwan;Park, Soo Hyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.6
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    • pp.477-483
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    • 2016
  • Velocity profiles of laminar, transition and turbulent boundary layers were investigated by using Particle Image Velocimetry(PIV) measurements on the flat plate at Mach 2.96. The Schlieren visualization and PIV measurements are also used to confirm whether the oblique shock wave generated from the leading edge affects the flow field over the flat plate. The laminar velocity profile measured from the experiment was well matched with the compressible Blasius solution. The velocity profile of the transition boundary layer was well correlated with the theoretical turbulent velocity profile from near the wall and the transition began from Re = $1.41{\times}106$. For the turbulent boundary layer, considering compressibility effects, the Van Driest-transformed velocity satisfies the incompressible log-law. It is found that the log region is extended farther in the wall-normal direction compared to the log region in incompressible boundary layer.

Effects of Pulsating Jet Blowing on Stall Control of Two Dimensional Elliptic Airfoil (이차원 타원형 날개꼴의 실속제어에서 간헐제트 브로잉의 효과)

  • Lee, Ki-Young;Sohn, Myong-Hwan;Jeong, Hung-Seok
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.9
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    • pp.1-8
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    • 2005
  • This paper explored the effects of separation control through the use of pulsating jet blowing on a two dimensional elliptical airfoil. To develop an active control technique of flow separation, a flow control actuator utilizing continuous/pulsed jet of pressurized air was designed and installed in a wind tunnel testing model of elliptic wing. PIV measurement and flow visualization of the wing near field were conducted to access the feasibility and effectiveness of the pulsed jet blowing on controlling the stall of the elliptical wing in subsonic flow. PIV experimental results show that separation control can provide significant reduction in turbulent flow wake and separation bubbles by jet blowing. The pulsating jet blowing is more effective on the separation control than continuous one. Increased jet frequency suppressed the turbulent separated flow wake effectively at even higher AOAs.