• Journal of Korean Society of Transportation
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• v.36 no.3
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• pp.216-228
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• 2018

In this study analyzed the ponding changing of plastic deformation section follwed time development to apply weather, geometry and traffic data in additon to time development to improve road management service and safety of roads during or after rain. After We selected an 8.3km section of old national highway the Seongnam-Janghowon section and created a three-demensional surface of terrain through the numerical transformantion of design drawing data, with reflection the linear data of the same coordinate system in order to describe more realistic roads, we design additional structures with shading above roads. The altitude and azimuth of the sun were calculated and set based on the longitude and latitude data of the survey line for the analysis of the sun rate, and the daylight impact zone was visualized by setting the shaded time to an interval of 1 hour and the shade rate of the corresponding section. In addition, the evaporation volume calculated from weather data such as temperature, humidity, radiant energy, and road temperature analyzes together, it will use the way of a safer and more efficient road management as grasping the ponding changing more efficent in time development.

• The Journal of the Korea Contents Association
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• v.16 no.10
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• pp.311-325
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• 2016

The communication via MIM(Mobile Instant Messenger) has unique characteristics; one of them is use of emoticons. Although using emoticons in MIM is getting a lot of attention from business fields and emoticons markets in MIM is growing rapidly, there are little researches focused on emoticons in MIM in consumer behaviors and marketing area. So, the purpose of this study is to fill this theoretical and practical gap. For this purpose, we explore the effect of and trust in MIM system and attitude toward use of emoticons on purchase intention to emotions in MIM. Our study used structural equation modeling analysis; the results showed that perceived benefits and perceived risk to MIM affected trust in MIM system significantly, more specifically, while perceived benefits affected trust in MIM system positively, perceived risk affected trust in MIM system negatively. We also found that perceived usefulness of emoticon in MIM and flow experience influenced attitude toward use of emoticons positively. Lastly, trust in MIM system and attitude toward use of emoticons had positive effect on purchase intention to emoticons in MIM. The implication and limitations of this study are also discussed.

• Environmental and Resource Economics Review
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• v.15 no.4
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• pp.591-642
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• 2006

This paper intends to analyze economic impacts of commitment period and initial allocation in emissions trading using computable general equilibrium (CGE) modeling. The fully dynamic CGE model with perfect foresight assumption is employed to illustrate (i) how a model displays economic impact of $CO_2$ regulation upon different commitment periods: one-year budget clearing vs. 5-year commitment period, (ii) how major 8 energy-intensive industries respond to different ways to allocate initial allowances. According to the results of the analysis, it IS found that market players are motivated to bank the permits and tend to sell permits in earlier stage and to buy permits in later stage of commitment period. This implies that banking allows permit trading within a commitment period, which supports the conclusions of Kling and Rubin (1997). Other findings are related to efficiency. That is, emissions trading surpasses command and control, in terms of economic efficiency and longer terms of commitment period converge on lower permit price, In long term, initial allocation based on value-added performs the lowest GDP loss among different initial allocations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.344-352
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• 2020

The purpose of this study was to identify the latent classes in the changing patterns of marital conflict perceived by mothers to explore its relationship with the changing patterns of mothers' depression, school readiness, self-esteem, and happiness of their children five years after their birth. A total of 1,243 responses from the 1st (2008) to 5th (2012) and 7th (2014) to 10th (2017) Korean Child and Youth Panel Study(KCYPS) were analyzed by Latent Growth Modeling (LGM) and Growth Mixture Analysis (GMA). The results were as follows. First, three changing patterns in the mothers' perceived marital conflict groups were identified: low-low changing, average-uptrend, and high-unchanging group. Second, an increasing pattern of depression was found from mothers of high-unchanging group over five years. Third, school readiness for their children was differentiated according to the latent classes. In particular, children from the low-low changing group showed higher readiness as well as self-esteem and happiness. Fourth, children from mothers of the low-low changing group showed high self-esteem and happiness in lower grades in elementary school. The results of this study suggest that the mothers' perceived marital conflict had an influence on themselves as well as their children's school related behaviors. Suggestions for an intervention program to resolve marital conflict are also discussed.

• Journal of Korea Water Resources Association
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• v.44 no.9
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• pp.711-720
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• 2011

SWAT (Soil and Water Assessment Tool) model was calibrated for the flow rate of the Deachung lake with a large area of 3108.29 $km^2$. Application of SWAT model requires significant number of input data and is prone to result in uncertainties due to errors in input data, model structure and model parameters. The SUFI-2 (Sequential Uncertainty Fitting Ver. 2) program and GLUE (Generalized Likelihood Uncertainty Estimation) program in SWAT-CUP (SWAT-Calibration and Uncertainty Program) are used to select the best parameters for SWAT model. Optimal combination of parameter values was determined through 2,000 iterative SWAT model runs. The Nash-Sutcliffe values and $R^2$ values were 0.87 and 0.89 respectively indicating both methods show good agreements with observed data successfully. RMSE and MSE values also showed similar results for both programs. It seems the SWAT-CUP has a great practical appeal for parameter optimization especially for large basin area and it also can be used for less experienced SWAT model users.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.10
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• pp.4331-4338
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• 2014

$N^1$-(2, 5-dimethoxyphenyl)-$N^8$-hydroxyoctanediamide (N25) is a novel SAHA cap derivative of HDACi, with a patent (No. CN 103159646). This invention is a hydroxamic acid compound with a structural formula of $RNHCO(CH_2)6CONHOH$ (wherein R=2, 5dimethoxyaniline), a pharmaceutically acceptable salt which is soluble. In the present study, we investigated the effects of N25 with regard to drug distribution and molecular docking, and anti-proliferation, apoptosis, cell cycling, and $LD_{50}$. First, we designed a molecular approach for modeling selected SAHA derivatives based on available structural information regarding human HDAC8 in complex with SAHA (PDB code 1T69). N25 was found to be stabilized by direct interaction with the HDAC8. Anti-proliferative activity was observed in human glioma U251, U87, T98G cells and human lung cancer H460, A549, H1299 cells at moderate concentrations ($0.5-30{\mu}M$). Compared with SAHA, N25 displayed an increased antitumor activity in U251 and H460 cells. We further analyzed cell death mechanisms activated by N25 in U251 and H460 cells. N25 significantly increased acetylation of Histone 3 and inhibited HDAC4. On RT-PCR analysis, N25 increased the mRNA levels of p21, however, decreased the levels of p53. These resulted in promotion of apoptosis, inducing G0/G1 arrest in U251 cells and G2/M arrest in H460 cells in a time-dependent and dose-dependent manner. In addition, N25 was able to distribute to brain tissue through the blood-brain barrier of mice ($LD_{50}$: 240.840mg/kg). In conclusion, our findings demonstrate that N25 will provide an invaluable tool to investigate the molecular mechanism with potential chemotherapeutic value in several malignancies, especially human glioma.

• Journal of the Korean Chemical Society
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• v.51 no.5
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• pp.459-470
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• 2007

The structural equation modeling techniques were used to assess a model of chemistry learning strategy based on self-handicapping tendency and goal orientation. Data were collected during chemistry lessons in two high schools. In the optimal model II-2 of this research, the self-handicapping tendency was negatively related to the use of self-efficacy. The learning goal was positively related to the use of self-efficacy and to learning strategy. The performance- approach goal was positively related to self-efficacy but presented an negative relationship to learning strategy. The performance-avoidance goal was negatively related to self-efficacy but presented an positive relationship to learning strategy. Besides affecting the learning strategy through self-efficacy indirectly, the learning goal, performance-approach goal, and performance-avoidance goal affected learning strategy directly. The self-handicapping tendency and performance- avoidance goal were a negative predictors of self-efficacy, but the learning goal and performance-approach goal were a positive predictors. And the self-efficacy affected learning strategy positively. The implications of these findings for learning strategy in chemistry are discussed. Although the paths model of relationships of the motivations to learn and learning strategies in chemistry education as mentioned above is established, the more systematic search for the higher self-efficacy and learning strategy in different courses and curriculums may be needed.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.78-86
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• 2014

In this paper, a novel intensity-based fiber optic vibration sensor using a mass-spring structure, which consists of four serpentine flexure springs and a rectangular aperture within a proof mass, is proposed and its feasibility test is given by the simulation and experiment. An optical collimator is used to broaden the beam which is modulated by the displacement of the rectangular aperture within the proof mass. The proposed fiber optic vibration sensor has been analyzed and designed in terms of the optical and mechanical parts. A mechanical structure has been designed using theoretical analysis, mathematical modeling, and 3D FEM (Finite Element Method) simulation. The relative aperture displacement according to the base vibration is given using FEM simulation, while the output beam power according to the relative displacement is measured by experiment. The simulated sensor sensitivity of $15.731{\mu}W/G$ and detection range of ${\pm}6.087G$ are given. By using reference signal, the output signal with 0.75% relative error shows a good stability. The proposed vibration sensor structure has the advantages of a simple structure, low cost, and multi-point sensing characteristic. It also has the potential to be made by MEMS (Micro-Electro-Mechanical System) technology.

• Management & Information Systems Review
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• v.31 no.2
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• pp.21-39
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• 2012

To examine how usage of social network services(SNS) can affect users' satisfaction through their involvement to SNS. This study first explored the usage motives on the SNS by reviewing previous studies which are from the perspectives of usage and gratification theory. The structural equation modeling(SEM) approach was used to validate the model and Lisrel was used to analyze 306 data which were collected from college students who have SNS using experiences. The results showed that the motives of information seeking and self-expression have no significant influence on affective involvement to SNS and other hypotheses were all accepted. In order to investigate the relationship of usage motives-involvement-satisfaction between different genders, path analysis in male group and female group were done respectively. The results showed that in the case of male group, the motivation of information seeking, entertainment, and self-expression have positive effect on affective involvement, while only the entertainment motive can increase the cognitive involvement. In the case of female group, socializing motive and entertainment motive have positive effect on both affective involvement and cognitive involvement, but the information seeking motive and self-expression motive can not influence the formulation of emotion in SNS.

• The Journal of the Korea Contents Association
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• v.13 no.2
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• pp.359-369
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• 2013

In this study, the relationship between social support and adolescent mental health was examined. A primary aim was to investigate how family, school, and friends affect adolescent mental health including depression, stress, and anger issues. This study also intended to investigate the indirect effect of these factors through the mediator, problem drinking. The study used survey data collected from the "2010 The Study on Mental Health of Korean Adolescents" conducted by National Youth Policy Institute, and 942 subjects were selected for this study. The study hypotheses were tested using SEM (Structural Equation Modeling) analysis. Analyses revealed that the appropriate functions and roles of the family members had the effect of promoting mental health of adolescents. Inappropriate functions and roles of the family members induced problem drinking, and this eventually had a negative impact on mental health causing depression, stress, and angel problems. Results also showed that having more friends who drink alcohol or smoke cigarette had no direct effect on the mental health of adolescents; however, there was an indirect effect through the mediator variable, problem drinking. The finding of this study revealed the need and importance of appropriate social support system and environment in order to promote mental health of adolescents.