• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.7
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• pp.98-104
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• 2004

A spacecraft alignment measurement requires highly precise measurement accuracy which is less than ${\pm}0.5^{\circ}$. In general, such an alignment measurement has been performed by using three or more theodolites. However, it contains the latent accuracy error because of a position stability of spacecraft, etc. The new alignment measurement system which consists of a theodoilte, a rotating table and a digital inclinometer has been developed to possibly to possibly reduce the error. This paper describes the concept and methodology of methodology of measurement system. It was found that new measurement system can provide more accurate results than the conventional system.

• Journal of the Semiconductor & Display Technology
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• v.17 no.1
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• pp.45-49
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• 2018

Portable microcontroller based measurement unit is demonstrated using digital-to-analog convertor module, analog-to-digital convertor module and additional preamplifier circuit with low-budget but excellent performances. Using the designed measurement unit, the measurement of current below 1 nA with applying voltage up to 5 V is successfully carried out. With the WiFi module in microcontroller, measured data is transferred to the user's computer. To evaluate the performance of the measurement unit, the transfer curve of a commercial N-type field effect transistor was measured with the measurement unit and the results is well consistent with that measured using commercial characterization system.

• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.173-177
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• 2009

Digital holographic microscopy allows optical path difference measurement. Optical path difference depends on the both refractive index and morphology of sample. We developed a dual-wavelength in-line digital holographic microscope that can measure simultaneously the refractive index and morphology of a sample, providing highly precise three-dimensional information. Here we propose theoretical and experimental methods for dual-wavelength in-line digital holographic microscopy. The measured data were reasonable, although there was data error. By improving the experimental method, we could measure the refractive index more precisely and obtain more accurate three-dimensional information on samples.

• Journal of the Optical Society of Korea
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• v.17 no.5
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• pp.399-404
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• 2013

This article proposes a digital image correlation (DIC) strain measurement method based on a finite element (FE) algorithm. A two-step digital image correlation is presented. In the first step, the gradient-based subpixels technique is used to search the displacements of a region of interest of the specimen, and then the strain fields are obtained by utilizing the finite element method in the second step. Both simulation and experiment processing, including tensile strain deformation, show that the proposed method can achieve nearly the same accuracy as the cubic spline interpolation method in most cases and higher accuracy in some cases, such as the simulations of uniaxial tension with and without noise. The results show that it also has a good noise-robustness. Finally, this method is used in the uniaxial tensile testing for Dahurian Larch wood specimens with or without a hole, and the obtained strain values are close to the results which were obtained from the strain gauge and the cubic spline interpolation method.

• Journal of the Ergonomics Society of Korea
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• v.20 no.1
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• pp.73-86
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• 2001

An analysis of anthropometric data of feet of Korean adults was made in this study. Anthropometric data were measured with the direct measurement method and indirect measurement method. Martin scales and a tapeline were used for direct measurement. Digital images taken with a digital camera as an indirect measurement method were analyzed using AutoCAD program. Total 114 adults aged from 20's to 40's participated in this study. Especially right and left feet were measured. Right and left side were compared and differences according to age were compared too. Feet shape, arch height, and deformation of toe were analyzed. The comparison between right and left foot showed that many subjects had different anthropometric data in their feet. Feet deformation including arch height and claw toe shape showed very serious status. Close and continuous attention to feet deformation is strongly needed.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.3
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• pp.233-238
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• 2006

In order to solve power disturbances, power components measurement for both supply and demand side of power system must be implemented. This paper proposed a DSP (Digital Signal Processor)-based multi-channel (voltage 8-channel and current 10-channel) power components measurement system that simultaneously can measure and analyze power components for both supply md demand side. After voltage and current measurement accuracy revision using YOKOGAWA 2558, the developed system was tested in the field.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.4
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• pp.225-235
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• 2010

People are getting more interested in 3D stereoscopic movie, but due to the sudden concern, there is less research how 3D stereoscopic movie influence on people. The present research aims at developing 3D stereoscopic movie measurement. For this, we tested three variables which are perceived functionality, impression, and presence. Perceived functionality is defined as how people perceive functions of 3D stereoscopic movie for instance depth, and impression is defined as how people integrate various information as a total image. Finally, presence is a psychological state that individual's perception fails to accurately acknowledge the role of the technology in the experience. As a result, perceived functionality consists of four factors, impression consists of eight factors, and presence consists of three factors. As an exploratory research, we cannot guarantee the validity of the measurement, but as a seminal research it is worthwhile to pay attention.

• Journal of the Optical Society of Korea
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• v.20 no.6
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• pp.770-777
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• 2016

It has been a challenge for researchers to accurately measure high temperature creep strain online without damaging the mechanical properties of the pipe surface. To this end, a noncontact method for measuring high temperature strain of a main steam pipe based on digital image correlation was proposed, and a system for monitoring of high temperature strain was designed and developed. Wavelet thresholding was used for denoising measurement data. The sub-pixel displacement search algorithm with curved surface fitting was improved to increase measurement accuracy. A field test was carried out to investigate the designed monitoring system of high temperature strain. The measuring error was less than $0.4ppm/^{\circ}C$, which meets actual measurement requirements for engineering. Our findings provide a new way to monitor creep damage of the main steam pipe of a boiler of an ultra-supercritical power plant in service.

• Knowledge Management Research
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• v.19 no.4
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• pp.149-170
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• 2018

Healthcare lifelog, a personal record relating to disease treatment and healthcare, plays an important role in healthcare paradigm shifts in which medical and information technology converge. Healthcare services based on various healthcare lifelogs are being launched domestically by both large corporations and small and medium enterprises, however, they are being built on an individual platform that is dependent on each company. Therefore, the terms of lifelog data are different as well as the measurement specifications are not uniform. This study proposes a reference model for minimum common data required for sharing and utilization of healthcare lifelog. Literature study and expert survey derived 3 domain, 17 essential items, and 51 sub-items. The model provides definition, measurement data format, measurement method, and precautions for each detailed measurement item, and provides necessary guidelines for data and service design and construction for healthcare service. This study has its significance as a basic research supporting the activation of ecosystem by ensuring interoperability of data between heterogeneous healthcare devices linked to digital healthcare platform.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.72.1-72.1
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• 2005