• Journal of the Korean Geotechnical Society
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• v.28 no.2
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• pp.33-42
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• 2012

The purpose of this study is to determine the effect of soil grain size and its distribution on soil-water characteristic. To do this, soil-water characteristic tests were conducted on Saemangeum silt using the axis translation technique. For comparison, the test was also conducted on Jumunjin sand. Using the test results, the soil-water characteristic curves (SWCCs) of Saemangeum silt and Jumunjin sand were predicted by Van Genuchten model. By comparison and analysis between two SWCCs, the silt shows higher values of matric suction, water content, and air entry value than the sand. On the other hand, the sand has higher values of Van Genuchten model parameters of ${\alpha}$, $n$, $m$ than the silt. It indicates that the SWCC is significantly dependent on the structure of soils. In other words, if a soil has relatively high grain size and poor grain size distribution curve, the values of saturated volumetric water content, residual volumetric water content, and air entry value are small, and the variation of volumetric water content is high in accordance with the matric suction variation, and consequently it shows a narrow range of funicular region.

• Journal of Industrial Technology
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• v.28 no.A
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• pp.19-22
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• 2008

In recent years, much attention has been paid to "Photocatalytic oxidation" as an alternative technique, where the pollutants are degraded by UV-irradiation in the presence of a semiconductor suspension such as titanium dioxide. $TiO_2$ is the most often used photocatalyst due to its considerable photocatalytic activity, high stability, non-environmental impact and low cost. 1n this research, the photocatalytic degradation of humic acid, acetaldehyde and methylene blue in $UV/TiO_2$ systems has been stydied. The effect of calcination temperature for manufacturing of $TiO_2$ photocatalysts and type of photocatalysts on photodegradation has been investigated. Photocatalysts with various metal ions(Mn, Fe, Cu and Pt) loading are tested to evaluate the effects of metal ions impurities on photodegradation. The photodegradation efficiency with $Pt-TiO_2$ or $Fe-TiO_2$ or $Cu-TiO_2$ is higher than Degussa P-25 powder. However, the photodegradation efficiency with $Mn-TiO_2$ is lower than Degussa P-25 powder. The photocatalytic properties of the nanocrystals were strongly dependent upon the crystallinity, particle size, standard reduction potential of various transition metal and electronegativity of various transition metal. As a result photocatalysts with various metal ion loading evaluated the effect of photodegradation.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1499-1504
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• 2004

The effects of absorbing materials on the characteristics of supersonic jet noise were experimentally investigated using a convergent-divergent nozzle with a design Mach number of 2.0. Overall sound pressure levels (OASPL) and noise spectra were obtained at far-field locations. Schlieren optical system was used to visualize the flow-fields of supersonic jets. In order to investigate the effect of absorbing materials, baffle plates of different materials (metal, grass wool and polyurethane foam) were installed at the exit of the nozzle. Experiment was carried out over a wide range of nozzle pressure ratios from 2.0 and 18.0, which corresponds to over- and under-expanded conditions. The results obtained show that the screech tone amplitude and the overall sound pressure level reduce by using the baffle plates of absorbing materials, compared with the metal baffle plate. It is also found that the characteristics of supersonic jet noise are strongly dependent on the size of baffle plate.

• Journal of Pharmaceutical Investigation
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• v.37 no.3
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• pp.131-135
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• 2007

A previous report recently demonstrated that ultrasound-induced hyperthermia (USHT:0.4 watts (W)/$cm^2$ at $41^{\circ}C$) could increase cellular uptake of P-glycoprotein (P-gp) substrates in P-gp expressing cancer cell lines. Since P-gp plays a major role in limiting drug permeability in the multi-drug resistant (MDR) cells, studies were conducted to elucidate the mechanism of USHT on cellular accumulation of P-gp and non-P-gp substrate in MDR cells. To accomplish this aim, we studied the effects of USHT on the accumulation of P-gp substrate, R123 and non-P-gp substrate, antipyrine in MDR cells. We demonstrated that USHT increased permeability of hydrophobic molecules (R123 and $[^{14}C]$-antipyrine). The enhanced permeability is reversible and size-dependent as USHT produces a much larger effect on cellular accumulation of $[^{14}C]$-antipyrine (MW 188) than that of R123 (MW 380.8). These results suggest that USHT could affect MDR cells more sensitive than BBMECs. Also, the present results point to the potential use of USHT to increase cellular uptake of P-gp recognized substrates, mainly anti-cancer agents into cancer cells.

• Korean Journal of Human Ecology
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• v.23 no.3
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• pp.529-544
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• 2014

The purpose of this study is to investigate the effect and potential problem of before and after technique in cosmetic surgery advertisements. This study would draw the positive and negative aspects in executing before and after technique by segmenting the surgical part(eyes, nose, and breast). And this study compared before and after technique with after technique and doctor(expert) endorser. Independent variables of this study are advertisement technique(before and after/after/doctor) and the kind of surgery(double eyelid surgery/ rhinoplasty/mastoplasty). Dependent variables of this study are general attitude toward advertising, hospital believability, ethical judgement toward advertising, intention to cosmetic surgery. This study is run as $3{\times}3$factorial design with 30 subjects per cell, resulting in a total sample size of 270. The result of this study shows that advertising technique in cosmetic surgery advertisement important variable to mediate the effect. This study found that before and after technique was more effective than any other techniques. Also, this study found that the kind of surgery variable should be considered in the execution of cosmetic surgery advertisement. Therefore, the result suggests that the kind of surgery and advertisement technique should be spontaneously considered by cosmetic surgery clinic and advertising regulation organizations for the effective communication way and consumer protection.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.45-51
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• 2009

A ground-loop heat exchanger in a ground source heat pump system is an important unit that determines the thermal performance of a system and its initial cost. The size and performance of this heat exchanger is highly dependent on ground thermal properties. A proper design requires certain site-specific parameters, most importantly the ground effective thermal conductivity, the borehole thermal resistance and the undisturbed ground temperature. This study was performed to investigate the effect of some parameters such as borehole lengths, various grouting materials and U-tube configurations on ground effective thermal conductivity. In this study, thermal response tests were conducted using a testing device with 9-different ground-loop heat exchangers. From the experimental results, the length of ground-loop heat exchanger affects to the effective thermal conductivity. Among the various grouting materials, the bentonite-based grout with silica sand shows the largest thermal conductivity value.

• Journal of The Korean Association For Science Education
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• v.16 no.3
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• pp.249-259
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• 1996

The purpose of this study was to analyze relationships among science achievement, science process skills and affective perception of high school students. The affective perception was included attitude toward science and science anxiety in the study. The instruments were developed HARS and SAMS for this study. The subject was sampled 1,115 students by stratified cluster sampling method. The major findings of this study were as follows: The tendency to affective perception was investigated according to students variables. Atittude toward science was showed a negative perception on female than male, in rural area than city. Science anxiety was percepted highly on female than male, in rural area than city. Attitude toward science showed positive relations to science process skills, science achievement, but which showed negative relation to science anxiety. Science anxiety showed negative relations among science process skills, science achievement and attitude toward science. Structural relationships among affective perception, science process skills and science achievement were analyzed by effect size through the path analysis on the independent and dependent variables. By the results, it was indicated that there have significant direct effect not only affective perception influence on science achievement but also on science process skills in hypothesized model. Prediction of science achievement and science process skills were clarified to characteristics of the affective perception.Therefore, understanding about affective perception will be helpful to make the strategy of science teaching

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6075-6080
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• 2014

Lung cancer is the leading cause of cancer-related death worldwide. Here we investigated the antitumor effect and mechanism of Zhejiang (Huzhou and Jiande) saffron against lung cancer cell lines, A549 and H446. Using high performance liquid chromatography (HPLC), the contents of crocin I and II were determined. In vitro, MTT assay and annexin-V FITC/PI staining showed cell proliferation activity and apoptosis to be changed in a dose- and time-dependent manner. The inhibition effect of Jiande saffron was the strongest. In vivo, when mice were orally administered saffron extracts at dose of 100mg/kg/d for 28 days, xenograft tumor size was reduced, and ELISA and Western blotting analysis of caspase-3, -8 and -9 exhibited stronger expression and activity than in the control. In summary, saffron from Zhejiang has significant antitumor effects in vitro and in vivo through caspase-8-caspase-9-caspase-3 mediated cell apoptosis. It thus appears to have more potential as a therapeutic agent.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.309-316
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• 2020

This research aims to revisit the hypothesis that bribery hurts firm performance in the context of a perceptibly corrupt country. Specifically, we use micro-data from Vietnamese small and medium firm surveys in 2013 and 2015 to examine whether bribery impedes firm revenue growth and labor productivity growth. An issue arising in this type of research is the potential endogeneity between firm bribing behaviors and firm performance. To go around the issue, we follow the literature to instrument bribery variable with the average probability of bribery in other provinces. We further employ the Analysis of Variance technique (ANOVA) to unveil if the effect of bribery is dependent on bribing purposes. The regression results show that firm performance is significantly influenced by firm size, firm age and firm bribing behavior. Larger firms are more likely to grow faster while firm performance tends to be negatively related to firm age. Particularly, we find that bribery significantly impedes firm revenue growth and labor productivity growth. The analysis of variance shows that the effect of bribery on firm performance may vary across bribing purposes. Our findings, therefore, support the sand-the-wheels hypothesis that bribery hurts firm performance even in a highly corrupt business environment.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.318.1-318.1
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• 2014

Metal nano-crystals have been received much attentions owing to their excellent catalytic property and surface plasmon effect. In the last decade, many studies on synthesizing well-dispersive nanoparticles and on understanding their distinct physical properties have been performed. There were tremendous reports revealing the electrochemical activities and enhancement of surface plasmonic effect were dependent mainly on the size, shape, and composition. So far, most fabrication methods have been based on vacuum based deposition techniques, such as chemical vapor deposition and electron-beam evaporation, and then annealed them to transform into the nanoparticles. Recently, there were several reports regarding to the photoinduced nano-crystal synthesis as an effective way to produce the metal nanoparticles. In this study, we report synchrotron x-ray mediated synthesis of Au nanoparticles on ZnO nanowires. ZnO nanowires were fabricated by hydrothermal method, and then they were dip into a solution having Au clusters. Detailed structural evolution of Au nanoparticles was investigated using scanning electron microscopy and photoluminescence measurements. The results on formation of well-dispersive Au nanoparticles on ZnO nanowires will be presented.