• Clean Technology
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• v.5 no.2
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• pp.25-35
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• 1999

Behavior of permeate flux decline was examined through the hollow fiber membrane in ultrafiltration system for Si colloidal solution. Flux decline with time was due to the growth of Si cake deposited on the membrane surface and the pore blocking by Si particles for the hollow fiber membrane. At the pseudo steady state of operation, the permeate flux of dead-end flow was 60 % to that of the cross flow. The ratio of permeate flux to the pure water flux, $J/J_w$, decreased with increasing the trans-membrane pressure, from 64.2 % for $0.5kg_f/cm^2$ to 45.7 % for $2.0kg_f/cm^2$. When the feed flow rate was 3 L/min, the pore blocking model was dominant at the initial period of filtration and was followed by the cake filtration model. And with increasing the feed flow rate from 1 L/min to 3 L/min, $R_c$ was $1.79{\times}10^{12}{\sim}2.34{\times}10^{12}m^{-1}$ which was the about 40 % decreased value to that of the 1 L/min while $R_p$ was not changed and was $1.71{\times}10^{12}m^{-1}$ approximately.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.4
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• pp.40-46
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• 2010

In this paper, we use the Raman spectra measured from platelet to the diagnosis of Alzheimer's disease(AD). The Raman spectra used in the experiments were preprocessed with the following method and then fed into the classifier. The first step of the preprocessing is a simple smoothing followed by background elimination to the original spectra to make it easy to measure the intensity of the peaks. The last step of the preprocessing was peak alignment with the reference peak. After the inspection of the preprocessed spectra, we found that proportion of two peak intensity at 743 and 757 $cm^{-1}$ and peak intensity at 1658 $cm^{-1}$ are the most discriminative features. Then we apply mapstd method for normalization. The method returned data with means to 0 and deviation to 1. With these two features, the classification result involving 278 spectra showed about 95.5% true classification in case of MLP(multi-layer perceptron). It means that the Raman spectra measured from platelet would be effectively used to the diagnosis of Alzheimer's disease.

• Journal of Korea Water Resources Association
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• v.47 no.5
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• pp.483-490
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• 2014

The design procedures for a biological reactor and a secondary settling tank (SST) of an activated sludge system are based on the steady state design method (Ekama et al., 1986; WRC, 1984) and the 1-D flux theory design method (Ekama et al., 1997), respectively. This study combined both of the design procedures, to determine the optimum sludge concentration in the reactor and the best design with the lowest cost. The best design of the reactor volume and the SST diameter at the optimum sludge concentration were specified with varying wastewater and sludge characteristics, temperature, sludge retention time (SRT) and peak flow rate. The effects of the influent wastewater characteristics, such as substrate concentration and unbiodegradable particulate fraction, were found to be considerable, but the effect of unbiodegradable soluble fraction was to be negligible. The effects of sludge settling characteristics, were also significant. SRT, as an operating parameter, was found to be an important factor for determining the optimum sludge concentration. However, the effect of temperature was found to be small. Furthermore, for designing a large scale wastewater treatment plant, the number of reactors or SSTs could be estimated, by dividing the total reactor volume or SST area. The new combined design procedure, proposed in this research, will be able to allow engineers to provide the best design of an activated sludge system with the lowest cost.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.2
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• pp.352-360
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• 1997

It has been reported that There is a relatively high incidence of congenital cleft lip and palate among congenital anomalies. Children with the cleft lip and palate confront various problems ranging from feeding difficulties as infants to frequent ear infections, compromised speech, aberrant dentofacial development, malocclusion and esthetic impairment with its unfavorable effects on the psychosocial adaptation of the individual. Management of these patients is a process that starts in infancy and continues on into adulthood. Through a team approach, professionals from various fields convene to assess the needs of the child and to assist the parents in dealing with the situation. A pediatric dentist, one of the team, must advise the parents the way of feeding or make an obturator for normal feeding and weight gain of infants with cleft lip and/or palate. An obturator can aid nursing, stimulate orofacial development, help develop the palatal shelves, prevent tongue distortions, prevent nasal septum irritation, decrease chance of ear infections, expand collaped maxillary segments, constrict the expanded anterior part of the maxilla, reposition the premaxilla, and help the parents psychologically. Three cases of infants with cleft lip and palate were managed with the obturator at the Dept. of Pediatric Dentistry, Kyung Hee University. In all cases, infants showed normal feeding and weight gaining after the insertion of the obturator.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.644-648
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• 2019

This study examined effects of the wall thermal conductivity coefficients on the thermal fluid phenomenon of a compartment fire. The reduced scale compartment was 0.4 m in width, 0.6 m in length and 0.6 m in height with a fire-board, which has a thermal conductivity coefficient of $0.18W/m{\cdot}K$. The local temperature at a 0.37 m height and the overall heat release rate were measured under the following experiment conditions: a $0.12m^2$ opening area and $0.01m^2$ pool size of a gasoline fire. The numerical results obtained by the Fire Dynamic Simulation were compared with the experimentally measured temperature. The deviations were within 10 % in the period of the steady state for maximum heat release rate (4.8 kW). The numerical results show that the average temperature of the compartment wall decreases by approximately 71 % with increasing thermal conductivity coefficient from $0.1W/m{\cdot}K$ to $100.0W/m{\cdot}K$ on the fixed heat release rate.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1B
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• pp.95-109
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• 2008

We numerically analyzed the nonlinear shoaling, a plunging breaker and its accompanying energetic suspension of sediment at a bed, and a redistribution of suspended sediments by a down rush of preceding waves and the following plunger using SPH with a Gaussian kernel function, Lagrangian Dynamic Smagorinsky model (LDS), Van Rijn's pick up function. In that process, we came to the conclusion that the conventional model for the tractive force at a bottom like a quadratic law can not accurately describe the rapidly accelerating flow over a swash zone, and propose new methodology to accurately estimate the bottom tractive force. Using newly proposed wave model in this study, we can successfully duplicate severely deformed water surface profile, free falling water particles, a queuing splash after the landing of water particles on the free surface and a wave finger due to the structured vortex on a rear side of wave crest (Narayanaswamy and Dalrymple, 2002), a circulation of suspended sediments over a swash zone, net transfer of sediments clouds suspended over a swash zone toward the offshore, which so far have been regarded very difficult features to mimic in the computational fluid mechanics.

• Journal of Astronomy and Space Sciences
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• v.12 no.1
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• pp.21-29
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• 1995

The $\beta$ Lyrae-type eclipsing binary AW Cam was observed photoelectrically in three wavelength regions. The obtained UBV light curves of AW Cam were analyzed with two separate modes(mode 2 for detached systems and mode 5 for semi-detached ones) of the Wilson-Devinney binary mode. It is intended to resolve the discrepancy in AW Cam system that the photometrio mass ratio (q=0.21) derived by Russo and Milano (1983) is not consistent with the spectroscopic result (q=0.43) by Mammano et al.(1967). Our photomtric solutions derived with mode 2 are fitted better to the observed light curves than those of mode 5, supporting that AW Cam may be not a normal semi-detached system but a detached one. Three dimensional Roche configuration of AW Cam system calculated with the derived mass ratio (q=0.43) reveals that the less massive secondary with the confined within its inner Roche lobe, while the more massive rimary is in marginally contact. From the Roche geometry, the constancy of the orbital period and other photometric evidences of AW Cam, it is provisionally concluded that the system is an unevolved detached binary in is provisionally concluded that the system is an unevolved detached binary in the phase of case A evolution toward 'contact phase' rather than and evolved one in 'broken-contact phase' suggested by Giuricin and Mardrossian (1981).

• Journal of Life Science
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• v.30 no.6
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• pp.542-549
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• 2020

A previous study reported that Ulmus macrocarpa Hance water extract (UME) can improve hyperlipid metabolism and the involvement of suppressed lipid synthesis through adenosine monophosphate-activated protein kinase (AMPK) pathway regulation was suggested. Further exploration of the lipid metabolism between liver and peripheral tissue was necessary to confirm that work, and so this study aimed to extend the possibility that UME can regulate serum lipids. After a 6-week in vivo trial of oral administration of UME to rats with induced hyperlipidemia, serum levels of triglyceride (TG) and total cholesterol (TC) were seen to decrease while HDL cholesterol increased. The UME administrations also decreased the TC and TG levels from the control in liver analysis. However, the suggestion that UME regulates the AMPK pathway to improve hyperlipid states through the suppression of hepatic lipogenesis seems to be only one part of the extract's effect. Indeed, serum concentrations of apolipoproteins A and B were returned to baseline levels of the control group in response to UME administration whilst the liver lipid content was much reduced; this cannot occur through the suggested suppression of hepatic lipogenesis alone. Therefore, a possible mechanism of UME could be that it improves blood circulation by modulating serum lipid levels through both the prior stimulation of lipid oxidation and the suppression of hepatic lipogenesis.

• Korean Journal of Optics and Photonics
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• v.22 no.4
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• pp.184-190
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• 2011

A compact imaging spectrometer (COMIS) was developed for a microsatellite STSAT-3. The satellite is now rescheduled to be launched into a low sun-synchronous Earth orbit (~700 km) by the end of 2012. Its main operational goal is the imaging of the Earth's surface and atmosphere with ground sampling distance of 27 m and 2 - 15 nm spectral resolution over visible and near infrared spectrum (0.4 - 1.05 ${\mu}m$). A flight model of COMIS was developed following an engineering model that had successfully demonstrated hyperspectral imaging capability and structural rigidity. In this paper we report the environmental test results of the flight model. The mechanical stiffness of the model was confirmed by a small shift of the natural frequency i.e., < 1% over 10 gRMS random vibration test. Electrical functions of the model were also tested without showing any anomalies during and after vacuum thermal cycling test with < $10^{-5}$ torr and $-30^{\circ}C\;-\;35^{\circ}C$. The imaging capability of the model, represented by a modulation transfer function (MTF) value at the Nyquist frequency, was also kept unvaried after all those environmental tests.

• Journal of Nutrition and Health
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• v.41 no.3
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• pp.254-263
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• 2008

This study was conducted to analyze the effect of isoflavone intake on prevention of chronic disease in middle and old aged man. In this study we used FFQ (Food frequency questionnaire) and the isoflavone intake level of the subjects was 25.10 mg per day. We divided the subjects into three group -high, medium, low isoflavone intake level- and investigated the relation among isoflavone intake level and clinical/anthropometric characteristics. The intake of isoflavone was inversely related with the body fat in male subjects. And we also divided the subjects into 2 groups with normal and abnormal clinical/anthropometric risk factor. The isoflavone intake level of the abnormal group with high TG, high WHR and high body fat was lower than the normal group. The main food source of isoflavone was soybean curd, bean sprout, soybean paste, soybean and soy milk, and we also investigated the relation between frequency of soybean food and anthropometric and clinical variables. The frequencies of soybean curd, soybean paste, soybean broth, soy milk, bean sprouts, peanuts, soybean and dambuk as well as intake of isoflavone were inversely correlated with some anthropometric and clinical variables such as blood pressure, TG, BMI, % body fat, and waist-hip ratio, whereas positively correlated with HDL cholesterol, muscle mass and bone density. We suggest that high consumption of soy products and isoflavone is associated with decreased blood lipid and body fat in middle and old aged man and might be useful for prevention cardiovascular diseases. From this study, we obtained valuable basic information on recommended isoflavone intake level and guidelines for the prevention of some chronic diseases/health problems.