• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.7-16
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• 2004

The purpose of this study was to find the characteristics of travel behavior and accessibility in terms of spatial structure. We analyzed travel behaviors and accessibility using a mode choice model and the Complementary Accessibility Index(CAI). The urban spatial structures that were compared were a compact city (CC) versus a sprawled city (SC), and high residential density districts (HD) versus low residential density districts (LD). First, CC and HDs residents had a shorter commuting distance than the CC and LDs residents. Second, behavior models showed that the use of Private cars for commuting in SCs was found to be greater than private car use in CCs, and that public transportation modes would be encouraged in CCs. Third, changes associated with the time and cost of commuting by private car generally affect the demand for public transportation modes in the CC. Also, analysis of cross elasticity suggests that changes of subway travel time affect the demand for buses very elastically. Fourth, the CAI of SC and LD were superior to the CC and HD even though the SC inefficient urban forms in terms of spatial structure. So, the spatial distribution of population density was also found to be an important factor affecting accessibility and energy savings.

• Korean Journal of Veterinary Research
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• v.51 no.3
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• pp.217-225
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• 2011

Glatiramer acetate (GA; Copaxone) has been shown to be effective in preventing and suppressing experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS). It has been recently shown that GA-reactive T cells migrate through the blood-brain barrier, accumulate in the central nervous system (CNS), secrete antiinflammatory cytokines and suppress production of proinflammatory cytokines of EAE and MS. Development of EAE requires coordinated expression of a number of genes involved in the activation and effector functions of inflammatory cells. Activation of inflammatory cells is regulated at the transcriptional level by several families of transcription factors. One of these is the nuclear factor kappa B ($NF{\kappa}B$) family which is present in a variety of cell types and involved in the activation of immune-relative genes during inflammatory process. Since it is highly activated at site of inflammation, $NF{\kappa}B$ activation is also implicated in the pathogenesis of EAE. In this study, we examined whether the inhibition of $NF{\kappa}B$ activation induced by GA can have suppressive therapeutic effects in EAE mice. We observed the expression of $NF{\kappa}B$ and phospho-$I{\kappa}B$ proteins increased in GA-treated EAE mice compared to EAE control groups. The immunoreactivity in inflammatory cells and glial cells of $NF{\kappa}B$ and phospho-$I{\kappa}B$ significantly decreased at the GA-treated EAE mice. These results suggest that treatment of GA in EAE inhibits the activation of $NF{\kappa}B$ and phophorylation of $I{\kappa}B$ in the CNS. Subsequently, the inhibition of $NF{\kappa}B$ activation and $I{\kappa}B$ phosphorylation leads to the anti-inflammatory effects thereby to reduce the progression and severity of EAE.

• Journal of Soil and Groundwater Environment
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• v.14 no.6
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• pp.1-18
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• 2009

A series of three-dimensional numerical simulations using a generalized multidimensional hydrodynamic dispersion numerical model is performed to simulate effectively and to evaluate quantitatively impacts of urbanization on density-dependent groundwater flow and salt transport in a coastal aquifer system, Suyeong-Gu, Busan, Korea. A series of steady-state numerical simulations of groundwater flow and salt transport before urbanization with material properties of geologic formations, which are established by numerical modeling calibrations considering all the urbanization factors, is performed first without considering all the urbanization factors. A series of transient-state numerical simulations of groundwater flow and salt transport after urbanization is then performed considering the urbanization factors individually and all together. Finally, the results of both numerical simulations are compared with each other and analyzed. The results of the numerical simulations show that density-dependent groundwater flow, salt transport, and seawater intrusion in the coastal aquifer system are intensively and extensively impacted by the urbanization factors. Especially, these urbanization factors result in the changes of the total groundwater volume and salt mass in the coastal aquifer system. However, such impacts of each urbanization factor are not spatially uniform but locally different.

• Korean Journal of Ichthyology
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• v.20 no.2
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• pp.105-111
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• 2008

A pelagic tuna longline research cruise in the eastern and central Pacific Ocean from September to October of 2006 was conducted to compare catch rates with the use of different hook type and bait combinations. Traditional tuna hooks (J 4) and three circle hook types (C15, C16, C18), along with five bait types (chub mackerel (CM), jack mackerel (JM), milkfish (MF), sardine (SD), and squid (SQ)) and hook number as a proxy for hook depth were evaluated for their effect on bigeye tuna catch rates (fish per 1,000 hooks) using Generalized Linear Models (GLMs). Results from 28 sets indicated significant differences in bigeye catch rates between individual longline sets and hook number. The GLM explained 33% of the deviance in bigeye catch rates with these two factors. An alternative model formulation included bait type which had a small effect (explaining 2.7% of the deviance) on catch rates. Hook type had a negligible and non-significant effect in the GLMs. These results indicate that all of the hooks and baits tested are equally effective at catching bigeye tuna and that hook number (depth) was the paramount operational factor in explaining bigeye tuna catch rates.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.3
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• pp.139-146
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• 2012

Natural hydroxyapatite powder was obtained from the calcination of bovine bones and its porous compacts were fabricated by pressureless sintering at 1100 and $1200^{\circ}C$ for 1h. To evaluate and compare their biocompatibility with porosity, we investigated the support of osteoblast cells growth and cytotoxicity using the MG-63 cell line model in vitro. Sintered hydroxyapatite ceramics have a porous microstructure with a relative density of 65 % at $1100^{\circ}C$ and 82 % at $1200^{\circ}C$. Cells adherence to the surface of hydroxyapatite ceramics was observed in a day after the cell culture, and the spreading of cytoplasm around the nucleus was shown after 3 day cell culture. Most of cells were extended to the surface of hydroxyapatite through the wide area. Cell viability was nearly the same till 3 days culturing. But the rate of cell growth is higher in the specimen sintered at $1100^{\circ}C$ than that of $1200^{\circ}C$. It indicates that the porosity is an important factor to enhance the cell viability in the porous hydroxyapatite ceramics derived from bovine bones.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.7 no.2
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• pp.164-176
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• 2000

Purpose : This study was done to identify the factors of decisional balance for smoking cessation among middle aged men in Korea. This was composed of a set of variables at the level of decision making when middle aged men decide to stop smoking. It was used to classify and identify the characteristics of the stages of change for smoking cessation to which the middle aged men belong, and was used to identify the variables of decisional balance which influenced the stages of change for smoking cessation in middle aged men. Methods : A convenience sample of 169 men who had smoked and were smoking, were between age 30 and 60 and lived in Seoul(mean age=44), were selected from the community. The data was collected from December 10, 1999 to February 28, 2000. The research instrument was the Decisional Balance Measure for Smoking Cessation (Velicer et al., 1985). and Stage of Change Measure(DiClemente et al., 1991). The data were analyzed using the SAS Program. Results : 1. According to stage of change measure, the 169 subjects were distributed in each stage of change for smoking cessation: in the pre-contemplation stage 63 subjects(32.7%), contemplation stage 60 subjects (35.5%), preparation stage 17 subjects(10.1%), and maintenance stage 29 subjects(17.2%). 2. Factor analysis identified 4 factors of decisional balance as appropriate factors for smoking cessation of middle aged men. There were named by the researchers; 1)'Perceived Burden to Self', 2)'Perceived Benefit to Others' 3)'Perceived Approval to Others', and 4)'Perceived Disapproval to Self'. 3. Analysis of variance showed that the three components, 1)'Perceived Burden to Self(F=8.50, P=.0001)', 2)'Perceived Benefit to Others(F=3.19, P=.025)' and 3)'Perceived DisApproval to Self(F=2.87, P=.038)were significantly associated with stage of change. 4. Through discriminant analysis, it was found that 'Perceived Burden to self' was the most influential variable in discriminating the four stages of change(pre-contemplation, contemplation, preparation, and maintenance). Conclusion : The results are consistent with the application of the Transtheoretical model, which has been used to understand how people change health behavior. Even though this study is a cross-sectional, not a longitudinal study, the findings of this study give useful information for smoking cessation intervention for the middle aged men.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.167-178
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• 2003

Damage and overbreak of the remaining rock induced by blasting can not be avoided during tunnel construction which may result in either short-term or long-term tunnel instability. Therefore, in this paper, a methodology to take into account the effect of blast-induced damage in tunnel stability assessment is proposed. Dynamic numerical analysis was executed to evaluate damage and overbreak of the remaining rock for the most common blasting pattern in road tunnel. Rock damage was quantified by utilizing the damage variable factor which is adopted proposed in continuum damage mechanics. The damaged rock stiffness and the damaged failure criteria are used to consider the effect of rock damage in tunnel stability analysis. The damaged geological strength index of the damaged rock was newly proposed from the relationship between deformation modulus and geological strength index. Also the Hoek-Brown failure criteria of the damaged rock was obtained using the damaged geological strength index. Analysing the tunnel stability with the consideration of the blast-induced damage of remaining rock, it was found that the extend of plastic zone and deformation increased compared to the undamaged rock. Therefore the short-term or long-term tunnel stability will be threatened when the rock damage from blasting is ignored in the tunnel stability analysis.

• Journal of the Korean Geotechnical Society
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• v.20 no.6
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• pp.95-107
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• 2004

In this paper, the rheological characteristics of slurry used fur slurry-shield tunnels were studied with emphasis on penetration characteristics. The slurry penetration was modeled by soil-filter clogging theory. The coefficient of particle deposition was suggested as an indicator of sin clogging during tunnel construction and calculated through model tests. The measured slurry weight, clogged in the base soil, was compared with the value obtained from clogging theory. Based on the testing results, a stability analysis of a tunnel face was performed to pinpoint the most influential factor affecting stability of slurry-shield tunnels. It was found that the stability of tunnel face is dependent on the ratio of infiltration velocity to the coefficient of particle deposition, and the penetration distance of slurry increases with the ratio of infiltration velocity to the coefficient of particle deposition. Since the stability of tunnel face decreases with the slurry penetration distance, it was necessary to add some additives in order to reduce the slurry penetration distance. It was found that the ground condition needs additives when the soil has the effective particle diameter$(D_{10})$ larger than 0.75mm. It was also found that the tunnel face stability due to slurry penetration is significantly affected by the tunnel advance rate.

• The Journal of Information Technology
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• v.5 no.1
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• pp.79-98
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• 2002

This study examines the association between valuation and accrual information. According to accounting based valuation model, firm's value consists of net book value and abnormal earnings. Net book value and abnormal earnings are determined as the manager's accounting policy. Discretionary accruals may signal the manager's value expectation or be noisy factor of accounting variables. The results of this study are as follows; First discretionary accruals are associated to stock prices negatively but non-discretionary accruals are not to stock prices. This result suggests that discretionary accruals and non-discretionary accruals are the differential factors of the firm value. Second, the product term of discretionary accrual and net book value are associated to the stock price negatively but the product term of non-discretionary accrual and net book value are not associated to the stock price. the results indicate that discretionary accruals are noisy factors of net book value information. Third, the product term of discretionary accrual and net income are associated to the stock price negatively and the product tenn of non-discretionary accrual and net income are also associated to the stock price negatively, the results suggest that discretionary accruals are noisy factors of earnings.

• The Journal of Advanced Prosthodontics
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• v.7 no.4
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• pp.271-277
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• 2015

PURPOSE. This study was to evaluate the marginal fit of two CAD-CAM anatomic contour zirconia crown systems compared to lithium disilicate glass-ceramic crowns. MATERIALS AND METHODS. Shoulder and deep chamfer margin were formed on each acrylic resin tooth model of a maxillary first premolar. Two CAD-CAM systems (Prettau$^{(R)}$Zirconia and ZENOSTAR$^{(R)}$ZR translucent) and lithium disilicate glass ceramic (IPS e.max$^{(R)}$press) crowns were made (n=16). Each crown was bonded to stone dies with resin cement (Rely X Unicem). Marginal gap and absolute marginal discrepancy of crowns were measured using a light microscope equipped with a digital camera (Leica DFC295) magnified by a factor of 100. Two-way analysis of variance (ANOVA) and post-hoc Tukey's HSD test were conducted to analyze the significance of crown marginal fit regarding the finish line configuration and the fabrication system. RESULTS. The mean marginal gap of lithium disilicate glass ceramic crowns (IPS e.max$^{(R)}$press) was significantly lower than that of the CAD-CAM anatomic contour zirconia crown system (Prettau$^{(R)}$Zirconia) (P<.05). Both fabrication systems and finish line configurations significantly influenced the absolute marginal discrepancy (P<.05). CONCLUSION. The lithium disilicate glass ceramic crown (IPS e.max$^{(R)}$press) had significantly smaller marginal gap than the CAD-CAM anatomic contour zirconia crown system (Prettau$^{(R)}$Zirconia). In terms of absolute marginal discrepancy, the CAD-CAM anatomic contour zirconia crown system (ZENOSTAR$^{(R)}$ZR translucent) had under-extended margin, whereas the CAD-CAM anatomic contour zirconia crown system (Prettau$^{(R)}$Zirconia) and lithium disilicate glass ceramic crowns (IPS e.max$^{(R)}$press) had overextended margins.