• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.95.3-95
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• 2002

A multi-channel electrostatic probe is utilized to determine gas flow rate in a cylindrical container. A numerical analysis is conducted to compare experimental measurement with the computed gas velocity in radial and axial directions.

• Korean Journal of Optics and Photonics
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• v.21 no.5
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• pp.190-194
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• 2010

A hybrid grating sensing device based on a side-polished fiber Bragg grating (FBG) with a polymer overlay is proposed for simultaneous measurement of external refractive index and temperature. The side-polished FBG, which is insensitive to ambient index change, is utilized for detecting temperature variation, and the polymer overlay is coated on the side-polished FBG for measurement of ambient index change. The temperature sensitivities of the side-polished FBG and the polymer overlay were measured to be 0.01 nm/$^{\circ}C$ and -0.58 nm/$^{\circ}C$, respectively, in a temperature range from $30^{\circ}C$ to $100^{\circ}C$. The ambient index sensitivities of the polymer overlay were measured to be 498.8 nm/RIU in an ambient index range from 1.33 to 1.39, 694.9 nm/RIU from 1.39 to 1.42, and 1312 nm/RIU from 1.42 to 1.44.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.309-313
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• 2011

It is necessary for patients to wait twice for the thyroid examination of thyroid uptake measurement and thyroid scan by using $^{99m}Tc$-pertechnetate. In the study, a method of simultaneous examination of thyroid uptake measurement and thyroid scan by one intravenous injection of $^{99m}Tc$-pertechnetate was suggested by using attenuation filter. As a result, there was a significant correlation between control group and experimental group according to existence of attenuation filter. Consequently, the simultaneous examination of thyroid uptake measurement and thyroid scan by one intravenous injection can be applied clinically.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.1
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• pp.97-103
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• 2013

This study proposes a path generation technique for simultaneous five-axis driving for ball bar measurement, which is equivalent to cone frustum machining as mentioned in the NAS979 standard. The technique is generalized for a 3D circular path, and it is applicable to all machine tools regardless of their structural configurations. A mathematical machine input model that consists of a five-axis machine tool, ball-bar measurement and conical path information as inputs is presented for easy NC code generation, simulation for various test conditions, and a measurement test. The movement range of rotary axes, which depends on various conditions, is mathematically analyzed based on the proposed conical path model. Moreover, the effect of the movement range on various conditions (apex angle and inclination angle, ball bar tilting acceptance angle, offset position of workpiece ball, etc.) is analyzed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.4 s.97
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• pp.404-411
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• 2005

To increase accurateness and reliability of the evaluation of power tool vibration transmitted to an operator, it is necessary to measure the grip and feed forces during the measurement of hand-transmitted vibration. In the study a system was invented to measure the vibration and the grip and/or feed force, which consists of a measurement handle and a PC with a data acquisition system and the corresponding software. Strain gauges and an accelerometer were mounted on the handle surface for the simultaneous measurement of the forces and the vibration. The program in the system makes it possible to monitor the grip and feed force during the tool operation so that the operator keeps the applying forces within the pre-determined range. Investigating the vibration total values, frequency-weighted root-mean-square accelerations at the handle, obtained in repetition for each power tool with control of the grip and feed force showed more consistency than those measured without force control. By using the system the experimenter can reduce random error of the measured vibration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.689-694
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• 2004

To increase accurateness and reliability of the evaluation of power tool vibration transmitted to an operator, it is necessary to measure grip and feed forces during the measurement of hand-transmitted vibration. In the study a system was invented to measure the vibration and the grip and/or feed force, which consists of a measurement handle and a PC with data acquisition system and the software. Strain gauges and an accelerometer were mounted on the handle for the simultaneous measurement of the forces and the vibration. The program in the system makes it possible to monitor the grip and feed force during the tool operation so that the operator keeps the applying forces within the pre-determined range. Investigating the vibration total values, frequency-weighted root mean square accelerations at the handle, obtained at various conditions with control of the grip and feed force showed more consistency than those measured without force control. By using the system the experimenter can reduce uncertainty of the measured vibration.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.185-189
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• 2005

For the simultaneous measurement of strain and vibration signal, a fiber Bragg grating sensor system with a dual demodulator was proposed. One demodulator using a tunable Fabry-Perot filter could measure low-frequency signal such as strain and the other demodulator using a coarse wavelength division multiplexer could detect high-frequency signal such as vibration signal using intensity demodulation method. In order to measure strain and vibration of the composite main wing model under static loading a real time monitoring program was developed. Also using intensity demodulation of CWDM, sensitivity and resolution at high frequency vibration were evaluated.

• 한국가시화정보학회:학술대회논문집
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• 2003.11a
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• pp.35-38
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• 2003

Simultaneous measurement of velocity and concentration fields in a stirred mixer flow using a combined Stereo-PIV/Planar-LIF technique is carried out. Instantaneous velocity fields and concentration fields represent the local flow characteristics. A baffle is perpendicularly attached to the Wall to remove inactive region which shows very slow dispersion. It is found that the baffle produces tip vortex and breaking the divided streamline, so that mixing efficiency could be increases significantly.

• Journal of Environmental Impact Assessment
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• v.5 no.1
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• pp.79-85
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• 1996

Simultaneous monitoring in many locations is necessary to evaluate the air quality and analyze future trend of a city, For this purpose, it is essential to install air pollution monitoring network. The first automatic air pollution monitoring network was introduced Seoul in 1973. As of 1995, 20 monitoring stations are now in operation. Concerning the management of the air pollution monitoring network, there was some argument among the relavant scholars, non-governmental organization(NGO) and the government organization. So far, there was no extensive evaluation and analysis about the network. The purpose of this study was to evaluate the representativeness of air quality monitoring network through actual measurement of the concentration of the air pollutant. The concentration of NOx was extensively measured widely in Seoul area three times using the TEA simple measuring technique. Even the judgement level for the area representativeness was lowered to 80%, Ssangmun-dong monitoring station tend to overestimate the pollutant concentration of the covered area. While, Sinlimdong monitoring station tend to underestimate the pollutant concentration of the covered area.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.8
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• pp.513-517
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• 2015

We proposed and demonstrated a simultaneous measurement method to detect the refractive index and temperature of a medium using a side-polished fiber involving FBG (fiber Bragg grating). The temperature of a medium was obtained by using the Bragg wavelength shift of FBG, while the refractive index of medium were calculated by using the transmission loss. The Bragg wavelength is independent on the refractive index of the covering medium placed on surface of side-polished fiber, while the transmission loss at off-Bragg wavelength highly depends on the environmental temperature because of thermo-optic effect of the medium.