• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.74-84
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• 2022

Vehicle average speed information which measured at a point or a short section has a problem in that it cannot accurately provide the speed changes on an actual highway. In this study, segment separation method based on vehicle big data for accurate micro-speed estimation is proposed. In this study, to find the point where the speed deviation occurs using location-based individual vehicle big data, time and space mean speed functions were used. Next, points being changed micro-scale speed are classified through gradual segment separation based on geohash. By the comparative evaluation for the results, this study presents that the link-based speed is could not represent accurate speed for micro-scale segments.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.95-101
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• 2007

Recently, small-animal imaging technology has been rapidly developed for longitudinal screening of laboratory animals such as mice and rats. One of newly developed imaging modalities for small animals is an x-ray micro-CT (computed tomography). We have developed two types of x-ray micro-CT systems for small animal imaging. Both systems use flat-panel x-ray detectors and micro-focus x-ray sources to obtain high spatial resolution of $10{\mu}m$. In spite of the relatively large field-of-view (FOV) of flat-panel detectors, the spatial resolution in the whole-body imaging of rats should be sacrificed down to the order of $100{\mu}m$ due to the limited number of x-ray detector pixels. Though the spatial resolution of cone-beam CTs can be improved by moving an object toward an x-ray source, the FOV should be reduced and the object size is also limited. To overcome the limitation of the object size and resolution, we introduce zoom-in micro-tomography for high-resolution imaging of a local region-of-interest (ROI) inside a large object. For zoom-in imaging, we use two kinds of projection data in combination, one from a full FOV scan of the whole object and the other from a limited FOV scan of the ROI. Both of our micro-CT systems have zoom-in micro-tomography capability. One of both is a micro-CT system with a fixed gantry mounted with an x-ray source and a detector. An imaged object is laid on a rotating table between a source and a detector. The other micro-CT system has a rotating gantry with a fixed object table, which makes whole scans without rotating an object. In this paper, we report the results of in vivo small animal study using the developed micro-CTs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.6
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• pp.8-13
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• 2015

Recently, Illumination industry of LED module has been focused to industry technology for energy conservation of nation. The LED device is excellent to power efficiency due to semiconductor light source element. And the application to the lighting circuit technology can be designed to the sensitive lighting system for human sensitivity control. In this paper, as a process for analyzing the operating temperature of standardized electronic device including LED device has analyzed about fusing character with in designed micro fuse for electronic device protection from the over current. Using the de-rating technique, which is performed to micro fuse fusing test in the range of $-30^{\circ}C{\sim}120^{\circ}C$ thermostatic chamber. To the output data in each temperature zone, it is performed to first-order linear fitting. Additionally, applying the resistance temperature coefficient and statistical data for the reliable analysis has derived to the metal element resistance of micro fuse with temperature change of the thermostatic chamber. As a research result, The changed temperature effect of thermostatic chamber was confirmed regarding fusing time change.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.3
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• pp.77-85
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• 2022

In this study, to diagnose the grinding state of a micro drill bit, a sensor attachment location was selected through random vibration analysis of the grinding unit of the micro drill-bit grinding system. In addition, the vibration data generated during the drill bit grinding were collected from the grinding unit for the grinding wheels under the steady and worn conditions, and data feature extraction and dimension reduction were performed. The wear of the micro-drill-bit grinding wheel was diagnosed by applying KNN, a machine-learning algorithm. The classification model showed excellent performance, with an accuracy of 99.2%. The precision, recall and f1-score were higher than 99% in both the steady and wear conditions.

• 보존과학연구
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• s.32
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• pp.89-98
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• 2011

It is quite difficult to identify its corrosion compound because they have a wide variety of crystal structures and they are mixed with two component. This study was conducted with the standard iron corrosion compounds through the analysis by Raman Micro-Spectroscopy, which aims to obtain standard Raman Data. To assess the reliability of standard iron corrosion compounds, SEM-EDS analysis and XRD analysis were conducted. Through SEM-EDS analysis, the elements of corrosion compound matched with those of standards iron corrosion compounds except Goethite. XRD analysis showed that the structures of corrosion compounds were identical to those of standard iron corrosion compounds, however, it was identified that Iron sulfate ($FeSO_4{\cdot}6H_2O$) is the Rozenite ($FeSO_4{\cdot}4H_2O$). Through Raman Micro-Spectroscopy analysis, the new peak was detected from the wavenumbers of hydroxide and iron oxide. It is considered that it is due to changes in the wavelength of the laser. As the wavenumbers of iron chloride and iron sulfate have been identified, eight kinds of Raman Data were obtained. It can be considered to contribute to cultral heritage for iron objects that Raman Micro-Spectroscopy analysis which is relatively easy to compare material properties and structures can be highly applicable to the research on cultural heritage with the limited amount of samples.

• The Journal of Industrial Distribution & Business
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• v.7 no.3
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• pp.27-36
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• 2016

Purpose - Considering the importance of housing needs to real estate market, domestic studies on real estate prices from the perspective of demand are basically based on macro-data, but relatively few are associated with micro-data of urban real estate demand. We try to find a reliable relation of elasticity of demand and commercial housing market. Research design, data, and methodology - In this paper, we have derived housing demand theoretic method and have utilized micro-data of residential family housing survey of downtown area in Kunming City in October, 2015 to estimate income elasticity and price elasticity of housing demand respectively and make a comparative analysis. Results - The results indicate that income elasticity and price elasticity of families with owner-occupied housing are both larger than those of families with rental housing. Income elasticity of housing demand of urban residential families in Kunming is far below the foreign average and eastern coastal cities level, however, the corresponding price elasticity is far higher. Conclusions - We suggest that housing affordability of urban families in western China are constrained by the level of economic development, and the current housing price level has exceeded the economic affordability and psychological expectation of ordinary residents. Furthermore, noticing the great rigidity of housing demand, the expansion space of housing market for improvement and for commodity is limited.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.689-690
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• 2008

In the present study, a micro holographic PTV (HPTV) system was used to experimentally investigate the structure of 3D flow within a curved micro-tube with varying Dean number. The employed HPTV system incorporated a high-speed digital camera to measure the temporal evolution of the 3D velocity fields of micro-scale fluid flows. With increasing Dean number, flow in the curved tube is transformed from a steady flow to a secondary flow with two counter-rotating vortices. In this study, to analyze the 3D flow characteristics in the curved section of tube at a high Dean number, the trajectories of fluid particles were obtained experimentally using the whole 3D velocity field data obtained by the micro HPTV technique. The mean velocity field distribution was then obtained by ensemble averaging the instantaneous velocity fields. These results would be helpful in the design of various passages within micro-scale devices or micro-chips and in understanding the mixing phenomena that occur in curved conduits along the trajectories of fluid particles.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.228-230
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• 2002

Recently, electric power reliability of our country has been improved. However, there are still remaining problems which are short-duration variations like instantaneous and momentary interruption and voltage sag by nature calamity ; typhoon, lightning, snow, etc. Besides, power quality ; harmonics, caused by using power electronics equipments, become a hot issue Malfunction of controller and stop machinery, and losing the important data are caused by poor power quality at a couple of second. Due to those, UPS, which is made up battery, has being used, but there are several disadvantages ; long charge and discharge time, environmental problem by acid and heavy metal, and short life time. As generally know, micro-SMES is a method to settle those mentioned. However, there need huge system apparatuses in order to verify the effect of system efficiency and stability considering the size of micro-SMES, the sort of converter type, and various conditions ; inner temperature, magnetic field, quench characteristic of micro-SMES, and etc. In this paper, in order to bring the mentioned above to a settlement, a micro-SMES is modeled with characteristics of micro-SMES is interfaced to EMTOC program using Fortran program interface method. We obtained hopeful answers and made the simulation model of micro SMES.

• 한국가시화정보학회:학술대회논문집
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• 2004.12a
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• pp.65-74
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• 2004

Measurement of concentration distributions of suspended particles in a micro-channel is out of the most crucial necessities in the area of Lab-on-a-chip to be used for various bio-chemical applications. One most feasible way to measure the concentration field in the micro-channel is using micro-LIF(Laser Induced Fluorescence) method. However, an accurate concentration field at a given cross plane in a micro-channel has not been successfully achieved so far due to various limitations in the light illumination and fluorescence signal detection. The present study demonstrates a novel method to provide an ultra thin laser sheet beam having five(5) microns thickness by use of a micro focus laser line generator. The laser sheet beam illuminates an exact plane of concentration measurement field to increase the signal to noise ratio and considerably reduce the depth uncertainty. Nile Blue A was used as fluorescent dye for the present LIF measurement. The enhancement of the fluorescent intensity signals was performed by a solvent mixture of water $(95\%)$ and ethanol (EtOH)/methanol (MeOH) $(5\%)$ mixture. To reduce the rms errors resulted from the CCD electronic noise and other sources, an expansion of grid size was attempted from $1\times1\;to\;3\times3\;or\;5\times5$ pixel data windows and the pertinent signal-to-noise level has been noticeably increased accordingly.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.154-159
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• 2005

The next generation of optical storage systems requires higher numerical aperture (NA) objective lenses and shorter wavelength laser in order to improve the unit areal density. A blu-ray technology satisfies a miniaturization and a high capacity which are the requirements of the portable device. In this paper, we analyze the optical performance of hybrid micro lens and do active alignment. The hybrid micro lens is manufactured by using a wafer based fabrication technology. Optical components of hybrid micro lens are evaluated. The measurement of the optical power, the spot size and the wavefront error awe performed to evaluate the hybrid micro lens with NA 0.85. Using the measured data, we estimate if the performance of hybrid micro lens corresponds to the designed performance. After the performance of hybrid micro lens is evaluated, the integrated optical pickup and the hybrid micro lens are assembled by active alignment using UV curing and the optical performance of SFFOP is satisfied with BD specifications.