• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.406-413
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• 2014

to valproic acid (VPA) during pregnancy produces ASD-like core behavioral phenotypes as well as hyperactivity in offspring both in human and experimental animals, which makes it a plausible model to study ASD-related neurobiological processes. In this study, we examined the effects of two of currently available attention defecit hyperactivity disorder (ADHD) medications, methylphenidate (MPH) and atomoxetine (ATX) targeting dopamine and norepinephrine transporters (DAT and NET), respectively, on hyperactive behavior of prenatally VPA-exposed rat offspring. In the prefrontal cortex of VPA exposed rat offspring, both mRNA and protein expression of DAT was increased as compared with control. VPA function as a histone deacetylase inhibitor (HDACi) and chromatin immunoprecipitation experiments demonstrated that the acetylation of histone bound to DAT gene promoter was increased in VPA-exposed rat offspring suggesting epigenetic mechanism of DAT regulation. Similarly, the expression of NET was increased, possibly via increased histone acetylation in prefrontal cortex of VPA-exposed rat offspring. When we treated the VPA-exposed rat offspring with ATX, a NET selective inhibitor, hyperactivity was reversed to control level. In contrast, MPH that inhibits both DAT and NET, did not produce inhibitory effects against hyperactivity. The results suggest that NET abnormalities may underlie the hyperactive phenotype in VPA animal model of ASD. Profiling the pharmacological responsiveness as well as investigating underlying mechanism in multiple models of ASD and ADHD may provide more insights into the neurobiological correlates regulating the behavioral abnormalities.

• Geotechnical Engineering
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• v.13 no.5
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• pp.75-88
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• 1997

In this study an iterative procedure for the analysis of drilled shafts was proposed on the basis of the load transfer mechanism. Special attention was given to the estimation of bearing capacity of drilled shafts which was compared with driven piles, and then with the results of pile load test. The load displacement at the pile head was calculated by load than sfer curves (t -z curves, q-z curves) by using Vljayvergiya, Castelli and hi -linear models. Bab ed on the analytical results, it is found that the behavior of drilled shafts is different from that of driven piles the smaller the skin friction mobilized at the pile-boil interface, the smaller the development of the bearing capacity. Hence the greater pile head movement is required to mobilize the same mainitride of bearing capacity. This trend is more noticeable in sand than in clay. It is also found that as the length-todiameter ratios increase, the dirtference of ultimate bearing capacity between drilled shafts and driven piles is becoming lass ger in sand, but it is minor in clay.

• Membrane Journal
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• v.20 no.4
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• pp.312-319
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• 2010

Carbon membrane materials have received considerable attention for the gas separation including hydrocarbon mixture of ingredients of the volatile organic compounds(VOCs) because they possess their higher selectivity, permeability, and thermal stability than the polymeric membranes. The use of activated carbon membranes makes it possible to separate continuously the VOCs mixture by the selective adsorption-diffusion mechanism which the condensable components are preferentially adsorbed in to the micropores of the membrane. The activated carbon hollow fiber membranes with uniform adsorptive micropores on the wall of open pores and the surface of the membranes have been fabricated by the carbonization of a thin film of phenolic resin deposited on porous alumina hollow fiber membrane. Oxidation, carbonization, and activation processing variables were controlled under different conditions in order to improve the separation characteristics of the activated carbon membrane. Properties of activated carbon hollow fiber membranes and the characterization of a gas permeation by pyrolysis conditions were studied. As the result, the activated carbon hollow fiber membranes with good separation capabilities by the molecular size mechanism as well as selective adsorption on the pores surface followed by surface diffusion effective in the recovery hydrocarbons have been obtained. Therefore, these activated carbon membranes prepared in this study are shown as promising candidate membrane for separation of VOCs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.477-477
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• 2008

For more than three decades, the gate dielectrics in CMOS devices are $SiO_2$ because of its blocking properties of current in insulated gate FET channels. As the dimensions of feature size have been scaled down (width and the thickness is reduced down to 50 urn and 2 urn or less), gate leakage current is increased and reliability of $SiO_2$ is reduced. Many metal oxides such as $TiO_2$, $Ta_2O_4$, $SrTiO_3$, $Al_2O_3$, $HfO_2$ and $ZrO_2$ have been challenged for memory devices. These materials posses relatively high dielectric constant, but $HfO_2$ and $Al_2O_3$ did not provide sufficient advantages over $SiO_2$ or $Si_3N_4$ because of reaction with Si substrate. Recently, $HfO_2$ have been attracted attention because Hf forms the most stable oxide with the highest heat of formation. In addition, Hf can reduce the native oxide layer by creating $HfO_2$. However, new gate oxide candidates must satisfy a standard CMOS process. In order to fabricate high density memories with small feature size, the plasma etch process should be developed by well understanding and optimizing plasma behaviors. Therefore, it is necessary that the etch behavior of $HfO_2$ and plasma parameters are systematically investigated as functions of process parameters including gas mixing ratio, rf power, pressure and temperature to determine the mechanism of plasma induced damage. However, there is few studies on the the etch mechanism and the surface reactions in $BCl_3$ based plasma to etch $HfO_2$ thin films. In this work, the samples of $HfO_2$ were prepared on Si wafer with using atomic layer deposition. In our previous work, the maximum etch rate of $BCl_3$/Ar were obtained 20% $BCl_3$/ 80% Ar. Over 20% $BCl_3$ addition, the etch rate of $HfO_2$ decreased. The etching rate of $HfO_2$ and selectivity of $HfO_2$ to Si were investigated with using in inductively coupled plasma etching system (ICP) and $BCl_3/Cl_2$/Ar plasma. The change of volume densities of radical and atoms were monitored with using optical emission spectroscopy analysis (OES). The variations of components of etched surfaces for $HfO_2$ was investigated with using x-ray photo electron spectroscopy (XPS). In order to investigate the accumulation of etch by products during etch process, the exposed surface of $HfO_2$ in $BCl_3/Cl_2$/Ar plasma was compared with surface of as-doped $HfO_2$ and all the surfaces of samples were examined with field emission scanning electron microscopy and atomic force microscope (AFM).

• Korea journal of population studies
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• v.30 no.2
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• pp.97-116
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• 2007

As the fertility level in Korea continues to drop with detrimental implications for the society, it has regained much attention of academics and policy makers. This study, building on the previous research on fertility behavior, attempts to explore the plan of young married women to have an additional child. While such plan is not always put into practice, it is still closely related to fertility behavior. In addition, it can provide useful clues to understanding behavior in the future. Utilizing a recent nationwide survey on marriage and fertility, the study analyzes the plan of further birth among young married women according to the number of their children. The results show that the plan for first child is quite universal as no difference is found by their socioeconomic and demographic characteristics. However, having plan for second child differs by the work status of husbands, presence of mother of young married women, and the sex of first child. The effects of first two factors suggest that young married women take into consideration stability of home economics and availability of care sharing. As for the plan for the child, the present and ideal sex composition of children appear most important. The results indicate that the mechanism of fertility progression differs by the current number of children. Thus, consideration of such differential would help us deepen our understanding of fertility behaviors and need to reflect in the study. The study also argues that comprehensive and systematic qualitative research should be accompanied by to capture complexity of fertility decision making process.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.34-34
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• 2012

Heavy storms rainfall has caused many landslides and slope failures especially in the mountainous area of the world. Landslides and slope failures are common geologic hazards and posed serious threats and globally cause billions in monetary losses and thousands of casualies each year so that studies on slope stability and its failure mechanism under rainfall are being increasing attention of these days. Rainfall-induced slope failures are generally caused by the rise in ground water level, and increase in pore water pressures and seepage forces during periods of intense rainfall. The effective stress in the soil will be decreased due to the increased pore pressure, which thus reduces the soil shear strength, eventually resulting in slope failure. During the rainfall, a wetting front goes downward into the slope, resulting in a gradual increase of the water content and a decrease of the negative pore-water pressure. This negative pore-water pressure is referred to as matric suction when referenced to the pore air pressure that contributes to the stability of unsaturated soil slopes. Therefore, the importance is the study of saturated unsaturated soil behaviors in evaluation of slope stability under heavy rainfall condition. In an actual field, a series of failures may occur in a slope due to a rainfall event. So, this study attempts to develop a numerical model to investigate this failure mechanism. A two-dimensional seepage flow model coupled with a one-dimensional surface flow and erosion/deposition model is used for seepage analysis. It is necessary to identify either there is surface runoff produced or not in a soil slope during a rainfall event, while analyzing the seepage and stability of such slopes. Runoff produced by rainfall may result erosion/deposition process on the surface of the slope. The depth of runoff has vital role in the seepage process within the soil domain so that surface flow and erosion/deposition model computes the surface water head of the runoff produced by the rainfall, and erosion/deposition on the surface of the model slope. Pore water pressure and moisture content data obtained by the seepage flow model are then used to analyze the stability of the slope. Spencer method of slope stability analysis is incorporated into dynamic programming to locate the critical slip surface of a general slope.

• Journal of Korea Port Economic Association
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• v.32 no.1
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• pp.123-133
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• 2016

LNG(Liquefied Natural Gas) bunkering has become an important issue with the enforcement of environment regulations in shipping industry required by the International Maritime Organization (IMO). With increased attention on LNG bunkering, many studies that focus on safety, regulation, demand forecasting, and the feasibility of LNG fueled ships have been carried out. However, most of the existing research has not included considerations of the price of LNG bunkering and its competitiveness. This paper, therefore, suggests ways to increase price competitiveness in the LNG bunkering market in the Busan Port. This paper analyzes the LNG bunkering supply mechanism by investigating various LNG bunkering terminal business in the LNG supply market. Factors that determine LNG bunkering price and its elasticity are also identified. Market players who want to operate LNG bunkering terminals in the Busan Port should introduce a merchandising trade method that is able to exclude the "Korea premium" in order to increase price competitiveness. This paper also suggests adoptable strategies such as the use of TPS (Terminal to Ship via Pipeline) type of bunkering service and the importance of location for minimizing initial investment cost.

• Journal of East Asia Management
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• v.2 no.1
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• pp.93-103
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• 2021

Struggle refers to the process of overcoming various difficulties for a goal. The spirit of struggle is a positive attitude and reaction reflected in the process of struggle. Cultivating the spirit of struggle of college students is the call of the new era. In essence, the cultivation of the spirit of struggle is a process of learning, which is in line with Bandura's Observation Learning Theory(Bandura, 1977):Attention, Maintenance, Reproduction and Motivation. The cultivation of College Students' spirit of struggle in the new era is also a learning process of enriched experience. It is necessary to cultivate the spirit of struggle into the soul of college students and make it become a habit of students. Moreover, it is crucial to carry out adaptive transformation of Bandura's observation learning theory. By studying the mechanism of the spirit of struggle of college students, taking innovation and entrepreneurship education as a means, and aiming at cultivating the connotation of President Xi's thought on socialism with Chinese characteristics for a new era, this paper constructs the AIST model for cultivating the spirit of struggle of college students in the new era. This model includes online learning acceptance platform(Acceptance), classroom experience stimulation platform(Inspiration), iterative training solidified platform (Solidification), and competition practice transfer platform(Transfer). The purpose of this model is to provide a practical way for universities to fulfill the fundamental task of moral education and cultivate qualified socialist builders and successors. The number of students using the online learning acceptance platform ranked the first among that of the similar courses in China; The classroom experience stimulation platform and the iterative training solidified platform support each other, with an effective rate of 97%; The competition practice transfer platform has realized the continuous growth of the number of awards won in competitions for three years. The direction of future efforts is to establish the external mechanism of the spirit of struggle, to ensure the effectiveness of classroom experience and iterative training, to cultivate teachers with coaching skills, and to accurately measure the transformation point of external and endogenous motivation.

• Asia Marketing Journal
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• v.15 no.4
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• pp.51-60
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• 2014

Previous research on loyalty program has verified the factors that influence redemption behavior and the understanding of the mechanism of redemption behavior with academic and practical implications. However, these research has not proven boundary conditions in which the phenomena can be strengthened or weakened- that is, the moderating effect remains unclear. The inclusion of moderating variables can provide a more extensive understanding of the mechanism of this behavior from academic and managerial perspectives alike. Therefore, this current research proposes regulatory focus as a moderating variable, which has received scarce attention in the study of loyalty program behavior, especially individual characteristic variables that, in turn, affect the consumers' purchasing behavior in various ways. Previous research on consumer decision making investigates the differential role of regulatory focus as a series of stages. Regulatory focus theory posits that people depend on the two types of regulatory focus when pursuing goals: promotion focus vs. prevention focus. The former induces tendencies to recognize a goal as a hope and ideal, as something that satisfies the need for accomplishment, and to be sensitive to the presence of a positive outcome of the match and to match the pursuit of goals. On the other hand, the latter tends to regard a goal as the responsibility or obligation to achieve the goal, has a tendency to avoid failure to meet a target, and is sensitive to the presence of the negative consequences that do not reach the target. The following propositions are suggested: 1) The effect of higher accumulation effort level on delaying point redemption speed will be relatively more pronounced for customers with prevention focus. 2) The effect of higher accumulation effort level on large redemption unit size will be relatively more pronounced for customers with prevention focus. 3) The effect of higher accumulation effort level on hedonic redemption ratio will be relatively more pronounced for customers with promotion focus. Therefore, this research provides a moderating variable that has the potential to be used as a reference for market segmentation and affects the relationship between point accumulation effort and three sides of point redemption behavior. On this basis, the direction for the future research on this issue is recommended. Future research could verify these propositions conducting a survey of customers' propensity of regulatory focus in conjunction with the history of the loyalty program of data. This would provide a more realistic effect on the usage behavior of loyalty program consumers by providing useful implications for both marketing practitioners and researchers.

• Journal of Life Science
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• v.33 no.12
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• pp.978-986
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• 2023

Inflammation by the innate immune system is a protective mechanism of the organism against infection-mediated environmental factors. It is also responsible for the pathogenesis of various human diseases, including the progression of cancer. Lichens are receiving increasing attention as a source of bioactive molecules with therapeutic potential for a variety of diseases. Additionally, the antioxidant, anti-inflammatory, and anticancer potential of lichen and its secondary metabolites have been widely reported. However, the underlying mechanism is still unknown. In the present study, to investigate molecular mechanisms of anti-inflammation and anti-cancer activity in the Antarctic lichen, Usnea aurantiaco-atra, methanol extract of Usnea aurantiaco-atra (MEUS) was used in vitro assays in RAW 264.7 macrophages cell and HCT116 colon cancer cells. Based on our data, MEUS had the anti-inflammatory activity through the modulation of main inflammatory indicators such as COX-2, IL-6, iNOS, TNF-α and NO production in a concentration-dependent manner. In addition, we observed that MEUS had cytotoxic activity against HCT116 colon cancer cells in a concentration-dependent manner, leading to a significantly reduced proliferation of the cancer cells through apoptotic induction by activating caspase-3. Taken together, this work firstly reported the anti-inflammatory and anti-cancer activities of an Antarctic lichen, Usnea aurantiaco-atra, and MEUS may provide a new insight into the molecular mechanisms underlying a link between inflammation and cancer.