• Journal of Biomedical Engineering Research
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• v.26 no.5
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• pp.295-300
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• 2005

We introduce an x-ray micro tomography system capable of high resolution imaging of a local region inside a small animal. By combining two kinds of projection data, one from a full field-of-view (FOV) scan of the whole body and the other from a limited FOV scan of the region of interest, we have obtained zoomed-in images of the region of interest without any contrast a nomalies. We have integrated a micro tomography system using a micro-focus x-ray source, a $1248\times1248$ flat-panel x-ray detector, and a precision scan mechanism. Using the cross-sectional images taken with the zoom-in micro tomography system, we measured trabecular thicknesses of femur bones in postmortem rats. To compensate the limited spatial resolution in the zoom-in micro tomography images, we used the fuzzy distance transform for the calculation of the trabecular thickness. To validate the trabecular thickness measurement with the zoom-in micro tomography images, we compared the measurement results with the ones obtained from the conventional micro tomography images of the extracted bone samples.

• Ocean and Polar Research
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• v.25 no.spc3
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• pp.423-426
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• 2003

The seawater exchange breakwater equipped with an oscillating water channel and water transmitting pipes has a very spectacular function that seawater supply can be greatly increased due to the upsurge of the water surface inside the channel at resonance condition which can be reached when the incident wave period becomes close to the natural period of the channel. The variations of the water level and period inside the channel are very important factors in enhancing the efficiency of sea water exchange, especially when designing the breakwater cross-section in shallow water zone which requires longer resonance period with the elongated horizontal projection of the channel. In the present study, a hydraulic experiment was performed varying the length of the oscillating channel, and the resonance periods and water surface variations are analyzed in terms of water transmission through the pipes.

• Human Ecology Research
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• v.53 no.3
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• pp.309-318
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• 2015

This study investigates to investigate the ageing effect on household demand for clothing, food, housing and medical care commodities in Korea using a demand system model. The cross-sectional and time-series data from Statistics Korea on urban household expenditures and age projection analyzed household demands of consumption commodities. The household head age and elderly population ratio were employed for proxy variables of ageing. Ageing variable elasticities of commodity demands were estimated. Study results show that ageing variables significantly influenced on a household demand for commodities; clothing and food consumption decreases; however, housing and medical care consumption increases with ageing. The elasticities of total consumption expenditures and price variables were estimated in the demand analysis; these two variables significantly impacted almost all of the household consumption for the studied commodities. This study provides an opportunity to examine how ageing influences household consumption for clothing, food, housing and medical care commodities as Korean society experiences a rapid ageing. It is also meaningful that this study conducted a quantitative measuring of the household demands for commodities that was different from past research on the household consumption expenditures for commodities.

• Particle and aerosol research
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• v.18 no.4
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• pp.97-107
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• 2022

The geometry of popular wave plate type mist eliminator for the wet flue gas desulfurization process was improved, fabricated, and experimentally evaluated. A Mist eliminator is a type of inertial particle collector which collection efficiency is proportional to the velocity of the gas phase. However, as the amount of re-entrainment is also proportional to the gas phase velocity, there is a limitation for the gas phase flow rate. Re-entrainment is one of the most important issues in a mist eliminator and is likely to occur as the input of the liquid phase and flow rate of the gas phase increase. In order to resolve this problem, the projection angle of the improved mist eliminator is set to 30° from the conventional one while maintaining the cross-section. With low flow rate conditions, the modified mist eliminator showed a similar pressure drop and overall collection efficiency. However, with conditions in which re-entrainment is obviously occurring, the modified mist eliminator showed better performance in draining droplets than the conventional one. As a result, the modified mist eliminator showed higher overall collection efficiency.

• Korean Journal of Remote Sensing
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• v.33 no.5_1
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• pp.559-570
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• 2017

A partial least squares regression (PLSR) model was developed to map the internal soluble solids content (SSC) of apples using a ground-based hyperspectral scanner that could simultaneously acquire outdoor data and capture images of large quantities of apples. We evaluated the applicability of various preprocessing techniques to construct an optimal prediction model and calculated the optimal band through a variable importance in projection (VIP)score. From the 515 bands of hyperspectral images extracted at wavelengths of 360-1019 nm, 70 reflectance spectra of apples were extracted, and the SSC ($^{\circ}Brix$) was measured using a digital photometer. The optimal prediction model wasselected considering the root-mean-square error of cross-validation (RMSECV), root-mean-square error of prediction (RMSEP) and coefficient of determination of prediction $r_p^2$. As a result, multiplicative scatter correction (MSC)-based preprocessing methods were better than others. For example, when a combination of MSC and standard normal variate (SNV) was used, RMSECV and RMSEP were the lowest at 0.8551 and 0.8561 and $r_c^2$ and $r_p^2$ were the highest at 0.8533 and 0.6546; wavelength ranges of 360-380, 546-690, 760, 915, 931-939, 942, 953, 971, 978, 981, 988, and 992-1019 nm were most influential for SSC determination. The PLSR model with the spectral value of the corresponding region confirmed that the RMSEP decreased to 0.6841 and $r_p^2$ increased to 0.7795 as compared to the values of the entire wavelength band. In this study, we confirmed the feasibility of using a hyperspectral scanner image obtained from outdoors for the SSC measurement of apples. These results indicate that the application of field data and sensors could possibly expand in the future.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.4
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• pp.283-289
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• 2014

This study was conducted to develop a non-destructive detection method for adulterated powder products using Raman spectroscopy and partial least squares regression(PLSR). Garlic and ginger powder, which are used as natural seasoning and in health supplement foods, were selected for this experiment. Samples were adulterated with corn starch in concentrations of 5-35%. PLSR models for adulterated garlic and ginger powders were developed and their performances evaluated using cross validation. The $R^2_c$ and SEC of an optimal PLSR model were 0.99 and 2.16 for the garlic powder samples, and 0.99 and 0.84 for the ginger samples, respectively. The variable importance in projection (VIP) score is a useful and simple tool for the evaluation of the importance of each variable in a PLSR model. After the VIP scores were taken pre-selection, the Raman spectrum data was reduced by one third. New PLSR models, based on a reduced number of wavelengths selected by the VIP scores technique, gave good predictions for the adulterated garlic and ginger powder samples.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.775-784
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• 2009

Weathered foliation could act as a critical failure plane because this type of plane tend to have low roughness and long extensions. A big constructed slope at $\bigcirc\bigcirc$ road construction site was failed due to the block movement along a fault zone which is parallel to foliation. Tectonic activity reactivated a fault zone parallel to foliation, and the fault clay within the shear zone metamorphosed retrogressively to chrolite. The failed block moved when the block weigh lost the balancing with the resisting force of the retrogressively metamorphosed chrolite. Evaluating the three dimensional distribution of the foliation was critical for establishing a plan for the stabilization of the slope. For this purpose, 10 boreholes were drilled as a lattice distribution, and the BIPS analyses are performed at each boreholes. The fractures measured in the boreholes are projected into 15 cross sections and their distributions are analysed, using Fracjection software. The projection analyse show that the strike of the foliation gets dipper towards left side of the slope. This geometry indicates that there are more failure block geometry at left side of the slope. Potential failure planes are searched using the projection method, and these information are provided for further support design.

• Journal of Korean Medicine for Obesity Research
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• v.8 no.1
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• pp.89-99
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• 2008

Objectives Obesity is not only a matter of accumulation of adipose tissue but also a projection of self-cognition. This study examined the association between low self-esteem and visceral obesity; visceral adipose tissue (VAT) and visceral adipose tissue /subcutaneous adipose tissue ratio (VSR). Methods This cross-sectional study was performed in pre-menopausal obese(BMI $\geq\;25\;kg/m^2$) women in Seoul, from 2007 to 2008 (n=54). Simple anthropometry including BMI and waist circumference and Computed Tomography (CT) including VAT and VSR were done. To measure self-esteem, Rosenberg self-esteem scale (SES) questionnaire was administered. Subjects were given written consent and this study was performed under the permission of institutional review board of Kyung-Hee East-west Neo Medical Center. Results There was a significant relationship self esteem (SES score) with visceral obesity (VAT and VSR). 1. SES was correlated with VAT (r=-0.377, p<0.01) and VSR (r= -0.400, p<0.01) significantly by Pearson Correlation. 2. VAT and VSR could be predicted from SES by Simple linear regression. VAT = -1.701 ${\times}$ (SES score) +161.191 ($R^2$=0.142) VSR = -1.09${\times}$$10^{-2}$ ${\times}$ (SES score) +0.858 ($R^2$=0.160) Conclusions This study proves that low self-esteem might contribute to visceral obesity in Korean pre-menopausal obese women. Self-esteem and psychological factor should be considered in treatment of visceral obesity in adult-women.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.1
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• pp.63-71
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• 1983

A dye-edge tracking algorithm was used to determine the corresponding points in the two images(anterior-posterior and lateral) of the digital subtraction biplane angiography. This correspondence was used to reconstruct three dimensional images of cerebral artery in a dog experiment. The method was tested by comparing the measured image of oblique view with the computed reconstructed image. For the present study, we have developed three new algorithms. The first algorithm is to determine the corresponding dye-edge points using the fact the dye density at the moving edge avows the same changing pattern in the two projection views. This moving pattern of dye-edge density is computed using a matching method of cross-correlation for the two sequential frames' dye density. The second algorithm is for simplified perspective transformation, and the third one is to identify the specific corresponding points on the small vessels. The present method can be applied to compute the blood velocity using the dye-edge displacement and the three- dimensional distance data.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.3
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• pp.189-194
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• 2013

Osteochondroma is a benign neoplasm, osseous projection surrounded with cartilage, 35.8% of benign osseous tumor, 8.5% of whole osseous tumor and usually arises from the skeletal bone. Osteochondroma is a cartilaginous derivation and relatively uncommon in the craniofacial bone. Osteochondroma of the mandible has slow growth rates which mainly affect women around forty years of age and it can appear through the coronoid process and mandibular condyle, especially in the medial half. Clinical finding associated with osteochondroma of condyle are primarily a palpable, painless temporomandibular area mass with facial asymmetry, malocclusion and midline deviations. Sometimes pain and dysfunction like trismus often accompany the anatomic derangement. Other features include malocclusion with open-bite on the affected side and cross-bite on the contralateral side. In this study, a 45-years old female patient exhibits pain on the left temporo-mandibular joint area and malocclusion due to loss of the molar region with osteochondroma on the top left of her mandibular condyle head. The patient is able to recover gradually from the symptom through treatments on manipulation, stabilization splint, arthroscopic lavage and surgical excision, thus, this is reported as a clinical case.