• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.1
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• pp.1-7
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• 2006

A method of the volumetric error measurement and calibration of NC machine tools is studied using an artifact method. In this study, a hole-pate is designed and machined using stainless steel. We tested and applied the hole-plate artifact in a commercial CMM(Coordinate Measuring Machine), after calibration of the hole-plate using a precise CMM. It has been shown that not only the measurement of geometric error components but also the 2D length error calculation in a working volume is available using the hole-pate artifact method. The results of study can also be used in NC machine with touch probe as the same method in CMM.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1530-1532
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• 2001

The displacement current measuring system used for detecting the dynamic behavior of monolayers at the air-water interface is described. It basically consists of a film balance, a pair of electrodes connected to each other through a sensitive ammeter. Here, one electrode is suspended in air and the other electrode is placed in the water. With Maxwell-displacement-current-measuring method, the phase transitons of Poly-$\gamma$-benzyl p-glutamate (PBDG) on a water surface were detected. Measured surface pressure, displacement current and dipole moment of monolayers of PBDG on the water surface. Also, we measured that compression velocity(30, 40, 50[mm/min]) when the sample spread volume was about 400[ul]. From the result, it is known that current is generated in the range of high surface pressures as compression velocity become faster.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.137-142
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• 2001

Since recent production system becomes that of the small quantity, large volume with high quality production, accurate and high speed inspection system is required. In such situation, noncontact 3D measurement system which utilized CCD cameras is useful technique in terms of system cost, speed of data acquisition, measuring accuracy and application. However, it has low accuracy compared with contact 3D measurement system because of the camera distortion, non uniformity of laser distribution and so on. For those reasons, in this paper precision enhancement method is studied considering radial camera distortion, and laser distribution. A distortion correction method is applied even to the standard lens. The laser slit beam trajectory is determined by 3 method: based of the Gaussian function signal approximation, the median method, the center of gravity method and the peak point of the Gaussian function method.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.46-48
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• 2007

In this study, we determined the optimum electrode pair for measuring the abdominal pressure using bio-impedance method. Because impedance changes differ from a weight, a height, contractile force, volume of muscle and blood other or whatever of individuals, it was quantified using values of impedance change, correlation coefficient and SNR. Our results showed the optimum electrode pair (1, 9) which could detect impedance changes due to an increase of the intensity of the abdominal pressure. The correlation coefficient and quadratic function between the RMS values of EMG and the impedance changes were 0.87 and $y=0.0014x^2$+0.0620x+0.6958, respectively. It demonstrated that the abdominal pressure could be measured non-invasively and simply using bio-impedance method. We propose that this optimum electrode configuration would be useful for future studies involving the convenient measurement of abdominal pressure by ambulatory urodynamics monitoring study.

• Journal of the Korean Society of Visualization
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• v.2 no.1
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• pp.12-17
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• 2004

The physical characteristics of soot near the soot inception point were investigated with various measurements. In-situ measurements of particle size and volume fraction were introduced based on time resolved laser-induced incandescence (TIRE-LII) and laser-induced ion mobility (LIIM). The one has more convenience and accuracy than conventional LII technique and the other works best for particle sizes of a few nanometers at high concentrations in a uniform concentration field. A complementary ex-situ measurement of particle size is nano differential mobility analyzer (Nano-DMA), which recently developed for measuring particle sizes between 2nm and 100nm and provides high-resolution size information for early soot. Particles will be also collected on transmission electron microscope (TEM) grids using rapid thermophoretic sampling and analyzed for morphology. These measurements will allow fresh and original insight into the characterizing soot inception process. The measured physical properties of incipient soot will clarify the controlling growth mechanism combined with chemical ones, and the dominant mechanism for soot modeling can be deduced from the information.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.205-210
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• 2004

The pulse detonation engine (PDE) has recently expected as a new aerospace propulsion system. The PDE system has high thermal efficiency because of its constant-volume combustion and its simple tube structure. We measured thrust of single-tube pulse detonation rocket (PDR) by two methods using the PDR-Engineering Model (full scale model) for ground testing. The first involved measuring the displacement of the PDR-EM by laser displacement meter, and the second involved measuring the time-averaged thrust by combining a load cell and a spring-damper system. From these two measurements, we obtained 130.1 N of time-averaged thrust, which corresponds to 321.2 sec of effective specific impulse (ISP). As well, we measured the heat flux in the wall of PDE tubes. The heat flux was approximately 400 ㎾/$m^2$. We constructed the PDR-Flight Mode] (PDR-FM). In the vertical flight test in a laboratory, the PDR-FM was flying and keeping its altitude almost constant during 0.3 sec.

• Journal of Sensor Science and Technology
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• v.24 no.2
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• pp.88-92
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• 2015

In order to study the semi-conductive characteristics of carbon black-filled ethylene-propylene-diene monomer (EPDM) composite film, which is used for measuring occlusal force, composite samples with volume ratios of carbon black to EPDM ranging from 30% to 70% were prepared. The process of making a composite film consists of two steps, which involve the preparation of a slurry composition and the fabrication of a thin film using solution casting and a lamination process. To prepare the slurry composition, we dispersed carbon black nanoparticles into an organic solvent before mixing with an EPDM solution in toluene. The mechanical and electrical properties of the resulting carbon black-filled EPDM film were then investigated, and the results showed that the electrical resistance of a film decreases with the increase in the carbon black content. Furthermore, improved elastic recovery was observed after cross-linking the EPDM.

• Fire Science and Engineering
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• v.22 no.3
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• pp.272-277
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• 2008

This study is performed for propose that exactly equivalent length of TBP in the applied at water-based fire protection system. For predict the measuring position of equivalent length, we determined the measuring position using the FVM about pressure drop of TBP. For the reckon of the exact about measured value we compared with the result of FVM and we knew the similar value each other. Using the results we proposed the friction loss measuring position that inlet of main dirction is 20 times of appellation diameter in main pipe, outlet of main dirction is 10 times of appellation diameter in main pipe and outlet of branched direction is 20 times of appellation diameter.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.159-162
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• 2015

In this paper, implement a baby monitor using the arduino for deaf and Visually Impaired. The proposed baby monitors are divided into measuring part & transmit part and linked with the application. The measuring part consists of a sound volume sensor, a transmit part consists of a bluetooth module. The measuring part and transmit part are controlled by the Arduino board. Measure the value of the sound by the sound sensor and delivers value to the arduino board. The measured value is sent to the application by the bluetooth module of transmit part. The application determines the received value and control the smart phone, and outputs the light from the sound and vibration for the value. It showed that the proposed baby monitor and an application is correctly operating in accordance with the value.

• The Journal of Korean Physical Therapy
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• v.31 no.4
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• pp.248-253
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• 2019

Purpose: To improve pulmonary function and decrease in balance ability with increasing forward head position and vertebral curvature, we applied Figure-8 brace to confirm the immediate effect on vital capacity and balance and to see if it is applicable. Methods: A total of 34 elderly women aged 65 or older and young women in their 20s with FHP were screened to measure vital capacity, measuring the forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC), and measuring the foot pressure to see the change in balance. For statistical analysis, the difference between pre and post values was compared using pared t-test. Results: As a result of vital capacity measurements, there was no significant difference between FEV1 and FVC for women over 65 years old (p>0.05). Young women in their 20s had no significant difference in FEV1 (p>0.05), and FVC had significant differences (p<0.05). In measuring foot pressure to measure balance, both women aged 65 and above and young women in their 20s had a significant decrease in anterior foot pressure, and a significant increase in posterior foot pressure (p<0.05). Conclusion: The results of this study did not positively affect the vital capacity of elderly women with FHP. However, the significant increase in vital capacity of young women in their 20s suggests that contraction of the abdominal muscle is necessary during forced expiration. Therefore, it is believed that proper application and therapeutic interventions should be combined when applying Figure-8 brace.