• Proceedings of the Materials Research Society of Korea Conference
• /
• 2002.11a
• /
• pp.99-99
• /
• 2002

• Progress in Superconductivity and Cryogenics
• /
• v.15 no.2
• /
• pp.48-51
• /
• 2013

The thermal contact resistance (TCR) is one of the important components in the cryogenic systems. Especially, cryogenic measurement devices using a cryocooler can be affected by TCR because the systems have to consist of several metal components in contact with each other for heat transferring to the specimen without cryogen. Therefore, accurate measurement and understanding of TCR is necessary for the design of cryogenic measurement device using a cryocooler. The TCR occurs at the interface between metals and it can be affected by variable factors, such as roughness of metal surface, contact area and contact pressure. In this study, we designed TCR measurement system at various temperatures using a cryocooler as a heat sink and used steady state method to measure the TCR between metals. The copper is selected as a specimen in the experiment because it is widely used as a heat transfer medium in the cryogenic measurement devices. The TCR between Cu and Cu is measured for various temperatures and contact pressures. The effect of the interfacial materials on the TCR is also investigated.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.11
• /
• pp.981-986
• /
• 2014

Printed electronics devices are made of several sets of printed patterns. The quality or printability of the printed patterns determines the electrical performance of such devices. Moreover, control of the printability determines the reliability of such devices. Despite its importance, few studies have been reported for the measurement of the printed patterns to evaluate their printability. In this study, a measurement method is proposed for printed patterns, including the definition of the properties to be measured, and the related software is described. The proposed method measures the width, pinholes, and edge waviness and evaluates the printability of the patterns quantitatively. The proposed measurement method could be an efficient tool to evaluate and enhance the printability of printed patterns in printed electronics.

• Proceedings of the KIEE Conference
• /
• 2001.11c
• /
• pp.34-37
• /
• 2001

In this paper, we designed and implemented the 60W DC characteristic measurement system for semiconductor devices. The proposed system is composed of 2 SMU(Source and Measure Unit)s, 2 HPU(High power Unit)s, 2VSU(Voltage Source Unit)s, and 2 VMU(Voltage Measurement Unit)s. HPU can source/measure voltage from -200V to 200V and source/measure current from -3A to 3A within 60W. Experimental results show that the implemented system can measure the power devices such as power BJT, regulator IC, and voltage detector.

• The Journal of Korean Association of Computer Education
• /
• v.14 no.2
• /
• pp.95-102
• /
• 2011

In this paper, we propose measurement-devices for the assessment of input vector consisted of face's movement as feature points through image processing based on AAM technique. The proposed method has been applied to classify students by 2-class(ADHD positive, ADHD negative). Experimental results show that the proposed method was successful in acquiring more objective and quantitative data than conventional methods, it takes advantage of examining without temporal and spatial constraints.

• 한국가시화정보학회:학술대회논문집
• /
• 2007.11a
• /
• pp.109-113
• /
• 2007

Micro-PIV is a well-known method for measurement of two- dimensional, two-component velocity in the microfluidic devices. Lots of the micro fluidic devices generate three-dimensional flow and 3D measurement of velocity is helpful to understand the physics of micro flow phenomena. In this study, we developed new micro 3D measurement method by applying 2-frame PTV in stereoscopic micro system. In this study, we did the validation study of SMPTV by using the simulated flow model to verify the accuracy and the feasibility of measurement and compared with SMPIV method. The results showed that SMPTV provides better spatial resolution and measurement accuracy than SMPIV method.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.23 no.6
• /
• pp.642-646
• /
• 2014

This research describes the measurement of roll parallelism by a laser interferometer. Parallelism among rolls is an important factor for improving the precision of printing devices. A laser interferometer, which is a device for the precise measurement of distance, can be utilized to measure parallelisms between rolls. To measure distance between two rolls by using a laser interferometer, the laser must not be severed during measurement. To achieve this condition, a linear motion guide was installed to each roll being measured, and continuous measurement of distance between two rolls was implemented by the simultaneous control of two mirrors installed on the guides. The method to measure parallelism between two rolls presented in this research can be utilized to improve printing precision by enhancing parallelism between rolls in printing devices.

• Journal of electromagnetic engineering and science
• /
• v.14 no.4
• /
• pp.336-341
• /
• 2014

Dosimetry of radiating electromagnetic wave from mobile devices to human body has been evaluated by measuring Specific Absorption Rate (SAR). Usual SAR measurement system scans the volume by robot arm to evaluate RF power absorption to human body from wireless devices. It is possible to fast estimate the volume SAR by software deleting robot moving time with the 2D surface SAR data acquired by arrayed probes. This paper shows the principle of fast SAR measurement and the measured data comparison between the fast SAR system and the robot scanning system. Data of the fast SAR is well corresponding with data of robot scanning SAR within ${\pm}3$ dB, and its dynamic range covers from 10 mW/kg to 30 W/kg with 4.8 mm probe diameter.

• Journal of Mechanical Science and Technology
• /
• v.17 no.12
• /
• pp.2099-2106
• /
• 2003

In this paper, a novel fast response NDIR analyzer (FRNDIR), which uses an electrically pulsed semiconductor emitter and dual type PbSe detector for the PPM-level detection of carbon dioxide (CO$_2$) at a wavelength of 4.28 $\mu\textrm{m}$, is described. Modulation of conventional NDIR energy typically occurs at 1 to 20 Hz. To achieve real time high-speed measurement, the new analyzer employs a semiconductor light emitter that can be modulated by electrical chopping. Updated measurements are obtained every one millisecond. The detector has two independent lead selenide (PbSe) with IR band pass filters. Both the emitter accuracy and the detector sensitivity are increased by thermoelectric cooling of up to -20 degrees C in all semiconductor devices. Here we report the use of semiconductor devices to achieve improved performance such that these devices have potential application to CO$_2$ gas measurement and, in particular, the measurement of fast response CO$_2$ concentration at millisecond level.

• Journal of Institute of Control, Robotics and Systems
• /
• v.18 no.8
• /
• pp.713-718
• /
• 2012

Lumber spine range of motion has been used to measure of physical and functional impairment by various tools from a ruler to 3D kinematic devices. However, pre-existing tools have problems in either movement or accuracy and reliability limitations. Accurate devices are limited by fixed space whereas simple devices are limited in measuring complex movements with less accuracy. In order to solve the location, movement and accuracy limitations at once, we have developed a novice measurement device equipped with accelerometer sensor and gyroscope sensor for getting three-dimensional information of motion. Furthermore, Kalman filter was applied to the algorithm to improve accuracy. In addition, RF wireless communication was added for the user to conveniently check measured data in real time. Finally, the measurement method was improved by considering the movement by a reference point. An experiment was conducted to test the accuracy and reliability of the device by conducting a test-retest reliability test. Further modification will be conducted to used the device in various joints range of motion in clinical settings in the future.