• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.6
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• pp.256-263
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• 2007

For $P_B=50Torr,\;P_T=5401Torr,\;T_S=450^{\circ}C,\;{\Delta}T=20K$, Ar=5, Pr=3.34, Le=0.01, Pe=4.16, Cv=1.05, adiabatic and linear thermal profiles at walls, the intensity of solutal convection (solutal Grashof number $Grs=7.86{\times}10^6$) is greater than that of thermal convection (thermal Grashof number $Grt=4.83{\times}10^5$) by one order of magnitude, which is based on the solutally buoyancy-driven convection due to the disparity in the molecular weights of the component A ($Hg_2Cl_2$) and B (He). With increasing the partial pressure of component B from 20 up to 800 Torr, the rate is decreased exponentially. It is also interesting that as the partial pressure of component B is increased by a factor of 2, the rate is approximately reduced by a half. For systems under consideration, the rate increases linearly and directly with the dimensionless Peclet number which reflects the intensity of condensation and sublimation at the crystal and source region. The convective transport decreases with lower g level and is changed to the diffusive mode at $0.1g_0$. In other words, for regions in which the g level is $0.1g_0$ or less, the diffusion-driven convection results in a parabolic velocity profile and a recirculating cell is not likely to occur. Therefore a gravitational acceleration level of less than $0.1g_0$ can be adequate to ensure purely diffusive transport.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.163-174
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• 2015

The Youngsan Lake was constructed to supply agricultural water to the extensive rice fields in the basin of the lake in 1981. Hypoxia has often developed in the bottom water of the lake during the warm season although the water depth is relatively shallow (< 16 m). We investigated the spatial and temporal variations of dissolved oxygen (DO) and physical properties such as water temperature, salinity and turbidity to elucidate the effects of change in physical properties on DO dynamics in the lake. Vertical profiles of DO, temperature, salinity, and water density were also explored to verify the development of stratification in relation to DO variation in the water column. Hypoxia (DO < $2mg\;L^{-1}$) was not observed in the upper regions whereas hypoxia was detected in the lower regions during the warm season. Thermocline generally developed in the lower regions during the warm season unlike the previous studies in which no thermocline was observed. However, water column was well mixed when freshwater water was discharged from the reservoir through the sluice gate of the dike. DO concentrations also decreased when halocline or pycnocline developed during the dry season suggesting that the vertical stratification of water column affects DO dynamics although the water depth is shallow in the Youngsan lake.

• Journal of Nutrition and Health
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• v.34 no.1
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• pp.62-68
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• 2001

The purpose of this study was to confirm that regular physical exercise habit and calcium intake play a role reducing the risk of cardiovascular diseae, particularly to confrim that regular exercise is important in reducing serum lipid levels. Subjects were classified into regular exercise group(more than 3 times/wk, more than 30 min per exercise) and non-regular exercise group. A convenient frequency method was used to assess the nutritional intake of subjects. Anthropometric measurement such as bodyweight and hight, and blood pressure were measured. There was no significant difference between nonexercisers and exerciser in energy intake, calcium intake and blood lipid levels. The strength of frequency of exercise may not by adequate to modify lipid profiles in premenopausal woman with normal lipid level, Although we found no significant difference in blood lipid levels, this result does not imply there are no benefits of exercise subjects. There were no signigicant correlations between age or weight with blood lipids in regular exercise group, while there were significant positive correlations between age of weight with blood lipids in non-regular exercise group. The levels of serum cholesterol, and triglyceride, blood pressure and atherogenic index increased with age in nonexercise women, Especially, atherogenic index was lower in regular exercise group. The blood pressure in nonexercise group was significantly higher than that in regular exercise group There was a highly significant negative correlation between calcium intake and blood pressure in nonexercise women, There was a highly significant negative correlation between calcium intake and blood pressure in nonexercise women. The results suggest that increased habitual physical activity and calcium intake may have desirable effects on serum lipid levels and blood pressure in premenopausal women.(Korean J Nutrition 34(1):62-68, 2001)

• Progress in Medical Physics
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• v.15 no.2
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• pp.77-83
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• 2004

The commissioning of a model-based treatment planning system requires many parameters to fit the measured depth doses and transverse profiles. For the commissioning of the Pinnacle$^3$ system, through the Monte Carlo (MC) simulation, the necessary parameters, including the photon spectrum, contaminant electrons, off-axis softening and fluency of photons, were observed. Through the simulation the parameters contained valuable information, but the calculated results of the Pinnacle$^3$ using the MC-derived parameters showed discrepancies with those measured for the off-axis softening and the fluency of photons. Even though the MC calculation produces reasonable values for the commissioning, the thorough physical basis of the Pinnacle$^3$'s commissioning process is needed in order to directly use the MC derived parameters.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.4
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• pp.409-415
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• 2013

We attempted to determine the action target of Shiitake mushroom extract with a known anti-hyperlipidemic effect in poloxamer(P) 407-induced hyperlipidemia model. We investigated the anti-hyperlipidemic effects of the water extract from Shiitake mushroom on the progress of high fat diet for 4 weeks. Experimental rats were divided into 5 different experimental groups including an normal group (normal diet; n=10), control group (hyperlipidemia; n=10), Experimental group I (hyperlipidemic rats treated with Shiitake mushroom extract (100 mg/kg, PO), n=10), Experimental group II (hyperlipidemic rats treated with Shiitake mushroom extract (300 mg/kg, PO), n=10), and Experimental group III (hyperlipidemic rats treated with Shiitake mushroom extract (500 mg/kg, PO), n=10). It is to analysis changes in body weight, visceral fat weight, blood lipid profiles, HMG-CoA reductase and histological findings. Body weight and epididymal fat weight was not significantly change in experimental groups (p>0.05). The level of total cholesterol, TG, arthrogenic index, and HMG-CoA reductase were significantly lower in experimental groups than control group (p<0.05). These results suggested that the Shiitake mushroom extract administration may act by inhibitory the release of cholesterol related factors and HMG-CoA from the hepatocyte without liver and kidney cell damage in hyperlipidemia rats.

• Architectural research
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• v.17 no.1
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• pp.13-20
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• 2015

The physical environment can dramatically affect students' feeling and their behavior, educational attainment, and the way in which we do school activities. Unlimited access to campus areas without appropriate securities have reported an increase of crime in school area and safety issues has encouraged school facility planners to install securities devices at every corner of buildings. However, it is still questionable whether this approach is enough to protect students and staffs from the victimization of crime, including thefts, burglaries and sexual offences. There has been continued doubt about the safety of educational facilities where individual college students are studying and enjoying extra-curricular activities. Therefore, the purpose of this study is intended to investigate the effects of perception of safety by students on the level of academic performance at public outdoor environment of university campus. An extensive literature noted that the central element of modern school design principle mainly holds the theory of crime prevention through environmental design (CPTED) and the concept of defensible space. The second generation of CPTED also focused on social soft issues as well as situational factors, which extends beyond mere physical design to include social factors. The correlation analysis found that the effect of sense of safety does appear to be statistically significant on the facilitation of academic achievement. However, the analysis of Chi-square concluded that the perception of safety was not related to demographic and socio-economic profiles of the group except for gender. Further, stepwise multiple regression analysis revealed that the most prime predictor for academic achievement were 'safe public outdoor space/paths' at university campus environment, implying careful design of public open space and sidewalks based on the guideline of CPTED. The study also demonstrated that as the level of positive perception of safety rose, the overall academic achievement also responded to the specified rate (${\beta}=.99$). Finally, the findings reinforce an evidence that high-quality school environments are a positive factor in student academic performance.

• Publications of The Korean Astronomical Society
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• v.15 no.spc1
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• pp.103-112
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• 2000

Symbiotic stars are known as binary systems of a giant with heavy mass loss and a white dwarf accompanied by an emission nebula. They often show bipolar nebulae, and are believed to form an accretion disk around the white dwarf component by attracting the slow but heavy stellar wind around the giant companion. However, the existence and physical properties of the accretion disk in these systems still remain controversial. Unique to the spectra of symbiotic stars is the existence of the symbiotic bands around $6830{\AA}$ and $7088{\AA}$, which have been identified by Schmid (1989) as the Raman scattered features of the O VI $1032{\AA}$ and $1038{\AA}$ doublet by atomic hydrogen. Due to the incoherency of the Raman scattering, these features have very broad profiles and they are also strongly polarized. In the accretion disk emission model, it is expected that the Raman features are polarized perpendicular to the binary axis and show multiple peak structures in the profile, because the neutral scatterers located near the giant component views the accretion disk in the edge-on direction. Assuming the presence of scattering regions outflowing in the polar directions, we may explain the additional red wing or red peak structure, which is polarized parallel to the binary axis. We argue that in the accretion disk emission model it is predicted that the profile of the Raman feature around $6830{\AA}$ is different from the profile of the $7088{\AA}$ because the O VI line optical depth varies locally around the white dwarf component. We conclude that the Raman scattered features are an important tool to investigate the physical conditions and geometrical configuration of the accretion disk in a symbiotic star.

• Korean Journal of Biological Psychiatry
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• v.13 no.2
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• pp.103-109
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• 2006

Objective : Associations of vascular risk/disease or apolipoprotein E ${\varepsilon}4$(APOE4) with geriatric depression has been unclear at a population level. This study aimed to evaluate whether there would be interactions of vascular risk/disease and APOE4 on depression in a Korean elderly population. Methods : 732 community residents aged 65 or over were assessed for depression(GMS), information on vascular risk/disease(reported stroke, transient ishemic attack, heart disease, hypertension, diabetes, smoking), examinations for vascular risk/disease(blood pressure, blood tests for glucose and lipid profiles, body size), APOE genotypes, demographic characteristics(age, gender, education), physical health, and cognitive function(MMSE). Results : Previous stroke and lower level of high density lipoprotein(HDL) cholesterol were significantly associated with geriatric depression independent of demographic characteristics, physical illnesses, and cognitive function. These associations were statistically significant only in those with APOE4, although the interaction terms didn't reach to statistical significance. Conclusion : Associations between vascular risk/disease and geriatric depression might be more prominent in those with APOE4. However further research would be needed to clarify this issue.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.4
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• pp.831-836
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• 2009

The aims of this investigation was to examine the anti-obesity effects of oral administration with Mulberry leaves extraction in the high-fat diet induced obesity rats. We investigated the anti-obesity effects of the extract from Mulberry leaves on the progress of high fat diet for 8 weeks. Experimental rats were divided into 5 different experimental groups including an normal group (normal dieat; n=10), control group (high fat diet; n=10), I (Mulberry leaves extraction 100 mg/kg oral administration induced obesity; n=10), II (Mulberry leaves extraction 300 mg/kg oral administration; n=10), and III (Mulberry leaves extraction 500 mg/kg oral administration; n=10). It is to analysis changes in body weight, epididymal fat weight, blood lipid profiles, and fat histological findings. Body weights were significantly increase in control group than normal groups(p<0.05). The level of total cholesterol, LDL-C and TG were significantly lower in experimental groups than control group (p<0.05). In histopathologic finding of fat-tissue around testicle experimental group I and II were more decreased than high fat diet-induced control group in fat cell size. These results suggested that the Mulberry leaves extraction oral administration made the increase of anti-obesity effect in high-fat diet induced obesity rats.

• Journal of the Korean Vacuum Society
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• v.6 no.3
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• pp.267-274
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• 1997

Silicon shallow trenches applied to the STI (Shallow Trench Isolation) of integrated circuits were etched using inductively coupled $Cl_2$ and HBr/$Cl_2$ plasmas and the effects of process parameters on the etch profiles of silicon trenches and the physical damages on the trench sidewall and bottom were investigated. The increase of inductive power and bias voltage in $Cl_2$ and HBr/$Cl_2$ plasmas increased polysilicon etch rates in general, but reduced the etch selectivities over nitride. In case of $Cl_2$ plasma, low inductive power and high bias voltage showed an anisotropic trench etch profile, and also the addition of oxygen or nitrogen to chlorine increased the etch anisotropy. The use of pure HBr showed a positively angled etch profile and the addition of $Cl_2$ to HBr improved the etch profile more anisotropically. HRTEM study showed physical defects formed on the silicon trench surfaces etched in $Cl_2/N_2$ or HBr/ $Cl_2$ plasmas.