• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1115-1123
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• 2008

When constructing projects such as road embankments, bridge approaches, dikes or buildings on soft, compressible soils, significant settlements may occur due to the consolidation of these soils under the superimposed loads. The compressibility of the soil skeleton of a soft clay is influenced by such factors as structure and fabric, stress path, temperature and loading rate. Although it is possible to determine appropriate relations and the corresponding material parameters in the laboratory, it is well known that sample disturbance due to stress release, temperature change and moisture content change can have a profound effect on the compressibility of a clay. The early research of Tezaghi and Casagrande has had a lasting influence on our interpretation of consolidation data. The 24 hour, incremental load, oedometer test has become, more or less, the standard procedure for determining the one-dimensional, stress-strain behavior of clays. An important notion relates to the interpretation of the data is the ore-consolidation pressure ${\sigma}_p$, which is located approximately at the break in the slope on the curve. From a practical point of view, this pressure is usually viewed as corresponding to the maximum past effective stress supported by the soil. Researchers have shown, however, that the value of ${\sigma}_p$ depends on the test procedure. furthermore, owing to sampling disturbance, the results of the laboratory consolidation test must be corrected to better capture the in-situ compressibility characteristics. The corrections apply, strictly speaking, to soils where the relation between strain and effective stress is time independent. An important assumption in Terzaghi's one-dimensional theory of consolidation is that the soil skeleton behaves elastically. On the other hand, Buisman recognized that creep deformations in settlement analysis can be important. this has led to extensions to Terzaghi's theory by various investigators, including the applicant and coworkers. The main object of this study is to suggestion the modified compression index value to predict settlements by back calculating the $C_c$ from different numerical models, which are giving best prediction settlements for multi layers including very thick soft clay.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.391-403
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• 2014

This study seeks to carry out a literary review of preceding studies and the health improvement model of Pender(1987) on university students majoring in nursing to explain the health improvement behaviors and identify the factors that affect their activities to provide a framework for developing a more effective nursing mediation method that promotes health improvement behaviors. The study subjects were 204 university students majoring in nursing who have had clinical practice experience. The period for data collection was from April 1to May 30, 2014 and a total of 204 copies of the questionnaire were used for analysis. For the collected data, frequency analysis, percentage, ANOVA, t-test and correlation analysis were conducted using SPSS, LISREL, and path analyss was done for hypothesis testing. The overall index of hypothesis model showed a good congruence as ${\chi}^2=.06$(p=.812), df=1, ${\chi}^2(df)=.000$, GFI=0.97, AGFI=1.0, SRMR=.002, NFI=0.947, NNFI=0.957, RMSEA=0.016, CN=266. Looking at the verification of the hypothesis presented in the model, the variables that affect health improvement behaviors were perceived disability, perceived self-efficacy, perceived social support, while stress from clinical practice, perceived health status, persistence and perceived benefits did not affect health improvement behaviors.

• The Journal of Bigdata
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• v.1 no.1
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• pp.67-75
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• 2016

The study analyzed big data extracted from Google and social media to identify factors related to searches on cyber bullying in Korea and America. Korea's cyber bullying analysis was conducted social big data collected from online news sites, blogs, $caf{\acute{e}}s$, social network services and message for between January 1, 2011 and March 31, 2013. Google search trends for the search words of stress, exercise, drinking, and cyber bullying were obtained for January 1, 2004 and December 22, 2013. The main results of this study were as follows: first, the significant factors stress were cyber bullying that Korea more than America. Secondly, a positive relationship was found between stress and drinking, exercise and cyber bullying both Korea and America. Thirdly, significant differences were found all path both Korea and America. The study shows that both adults and teenagers are influenced in Korea. We need to develop online application that if cyber bullying behavior was predicted can intervene in real time because these actual cyber bullying-related exposure to psychological and behavioral characteristic.

• Research in Community and Public Health Nursing
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• v.11 no.2
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• pp.333-346
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• 2000

The purpose of this study was designed to test and develope the structural model that explains health promoting behaviors among college students in Korea. The hypothetical model was constructed on the Pender's Health promotion Model(l996) and the inclusion of some influential factors for life satisfaction. The conceptual framework was built around eight constructs. Exogenous variables included in the model were self-esteem, perceived health status, self-efficacy, internal locus of control, chance locus of control. powerful other locus of control. Endogenous variables were health promotion behaviors and life satisfaction. The results are as follows; 1. The overall fit of the hypothetical model to the data was moderate <$x^2$=4.18(df=11. p=0.041), GFI= 0.99, AGFI= 0.76, RMR= 0.019, CFI= 0.99, CN= 248.50> 2. Path and variable of the model were modified by considering both its theoretical implication and statistical significance of parameter estimates. Compared to the hypothetical model. the revised model has become parsimonious and had a better fit to the data expected in a chi-square value <$x^2$=8.43( df= 16, p=0.21), GFI= 0.99, AGFI= 0.92., RMR= 0.024, CFI= 0.99, CN= 312.01> 3. Some of the predictive factors. especially self efficacy. self esteem. powerful others locus of control. perceived health status revealed the direct effects on health promoting behaviors. Of these variables. self-efficacy was the most signigicant factor. These predictive variables of health promoting behaviors explained 59% of total variances in the model. 4. Health promoting behaviors, self-esteem. and perceived health status revealed direct effect on the life satisfaction. Self-efficacy was identified as an important variable that contributed indirectly to improve life satisfaction by enhancing health promoting behaviors. These predictive variables of life satisfaction explained 42% of total variances in the model. In conclusion. the derived model in this study is considered appropriate in explaining and predicting health promoting models and life satisfaction among college students in Korea and could effectively be used as a reference model for further studies by suggesting a direction in health promoting nursing practices.

• Journal of the Korea Convergence Society
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• v.8 no.9
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• pp.301-309
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• 2017

This study analyzed the effect of cooperation activities among SMEs. In order to study empirical analysis, we classified the types of cooperation into four dimensions: technology cooperation, human resource cooperation, sales cooperation and financial cooperation. Review the role of the collaborative philosophy as a predictor. This study also analyzed the relationship between cooperation philosophy, cooperation activities and performance. The results of this study are as follows: First, the result of path analysis between cooperation philosophy and cooperation activities shows that cooperation philosophy has an important influence on technical cooperation, human resource cooperation, sales cooperation and financial cooperation. Second, the results of the relationship between cooperation activities and achievements, technical cooperation, human resource cooperation, and sales cooperation have an important influence on cooperation performance. The meaning of this study is as follows. Analyze empirical tests using the PSBP model from a partnership perspective. We are trying to verify the relationship with SMEs. Therefore, we can suggest a beneficial implication to explain the importance of cooperation activities between SMEs. Also, SME business units have a problem with technical information leakage when they form partnerships, but in order to overcome this problem, we can use cooperative philosophies and avoid negative views.

• Korea journal of population studies
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• v.31 no.1
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• pp.127-146
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• 2008

Over the past four decades reproductive behavior has changed slowly in much of the African countries. The average total fertility rate has fallen from six or more to near five today. Between 1960 and 2000 the largest fertility decline occurred in such Northern African countries as Algeria, Libya, and Morocco. The mortality rate has decreased in most African countries. The purpose of this study is to review the pattern of demographic transition in African countries. At first, this study focuses on the fertility transition. In Africa, the total fertility rate has decreased from 6.59 to 4.85 between 1960 and 2000. The mortality rate has also decreased in most of African countries. It is also interesting to find that there is a clear difference among African countries. In terms of infant mortality rate, Libya shows the lowest rate(17), while Mali and Somalia remain still high rate(142 and 133, respectively). This study tests a path model in which infant mortality rate acts as an intermediate variable between three socioeconomic variables and the fertility rate. The findings of this paper substantiate some of our hypotheses on the interrelationships among socioeconomic variables, infant mortality rate, and fertility rate. The result also shows the indirect effects of socioeconomic variables on fertility rate via infant mortality.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.5
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• pp.287-296
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• 2019

In this study, the effect of ground boundary conditions on the evaluation of blast resistance performance of precast arch structures was evaluated by a numerical analysis method. Two types of boundary conditions, namely, fixed boundary conditions and a perfectly matched layer (PML) were applied to numerical models. Blast loads that were much higher than the design load of the target structure were applied to compare the effects of the boundary conditions. The distribution and path of the ground explosion pressure, structural displacement, fracture of concrete, stress of concrete, and reinforcing bars were compared according to the ground boundary condition settings. As a result, the reflecting pressure shock wave at the ground boundaries could be effectively eliminated using PML elements; furthermore, the displacement of the foundation was reduced. However, no distinct difference could be observed in the overall structural behavior including the fracture and stress of the concrete and rebar. Therefore, when blast simulations are performed in the design of protective structures, it is rational to apply the fixed boundary condition on the ground boundaries as conservative design results can be achieved with relatively short computation times.

• Clean Technology
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• v.24 no.4
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• pp.293-300
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• 2018

Sulfamethoxazole (SMX) is sulfaamide-based synthetic antibiotics, which are widely prescribed pharmaceutical compound to treat bacterial infections in both human and animals. Most of them are not completely decomposed as refractory substances. The environmental impact of pharmaceuticals as emerging contaminants has generated severe concerns. In this study, catalytic wet peroxide oxidation (CWPO) of SMX was carried out with $Cu/Al_2O_3$ catalyst and investigated the optimum reaction conditions of temperature, dosage of catalyst and concentration of $H_2O_2$ to completely decompose the SMX. It was observed that SMX was completely decomposed within 20 min using 0.79 mM $H_2O_2$ and 6 g $Cu/Al_2O_3$ catalyst at 1 atm and $40^{\circ}C$, but SMX was not fully mineralized and converted to intermediates as hydroylated-SMX, sulfanilic acid, 4-aminobenzenesulfinic acid and nitrobenzene. After that these are completely mineralized through organic acid. We proposed the decomposition reaction path ways of SMX by analyzing the behavior of these intermediates. To investigate the durability of heterogeneous catalyst, decomposition of SMX was observed by continuously recycling catalysts. When the heterogeneous catalyst of 10 wt% $Cu/Al_2O_3$ was continuously reused 5 times, decomposition of SMX was a little lowered, but the activity of catalyst was overall very stable.

• The Journal of the Korea Contents Association
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• v.19 no.3
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• pp.659-674
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• 2019

The purpose of this study is to verify the path of the motivation, the flow, and problem gambling and intervention points. To this end, we verified the mediation effect of the motivation of the users outside sales offices influences the problem gambling through a flow and the moderated mediation effect of the frequency of the use of a bicycle racing tracks in that process. A total of 411 cases were analyzed using surveys conducted for one day on a weekday and weekend (September 13th and 15th 2018) for adults using an outside sales office in Jangan. According to the analysis, the causality of gambling by gambling motivation(amusement, excitement, avoidance, society, money) showed its effect positively by mediating the flow. The adjusted effect of the frequency of the use on the intermediary effect of the motivation ${\rightarrow}$ flow ${\rightarrow}$ problem gambling behavior, which is the main concern of this study, was found to be statistically significant. More specifically, the effect of adjusting the frequency of the use was statistically significant in both paths: motivation/flow and flow/problem gambling. It was also shown that, in the model with excitement, avoidance and social motivation, the adjustment of the frequency was only significant in the causal relationship between the flow and problem gambling. Based on these findings, this study made clinical and policy suggestions for intervention for gamblers and user protection regulations.

• Journal of the Korean Geotechnical Society
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• v.35 no.7
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• pp.15-27
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• 2019

The purpose of this study is to investigate the mechanism about damages occurring at quay wall and backfill in Youngilman Port during Pohang earthquake (M5.4) on November 15, 2017. In the field investigation, the horizontal displacement of the caisson occurred between 5 cm and 15 cm, and the settlement at backfill occurred higher than 10 cm. 2D-effective Stress Analysis was performed to clarify the mechanism for the damage. The input earthquake motion used acceleration ($3.25m/s^2$) measured at bedrock of Pohang habor. Based on a numerical analysis, it was found that the effective stress decreased due to the increase of excess pore pressure in the backfill ground and the horizontal displacement of the caisson occurred by about 14 cm, and the settlement occurred by about 3 cm. In backfill, the settlements occurred between 6 cm and 9 cm. This is similar to field investigation results. Also, it was found that the backfill soil was close to the Mohr-Coulomb failure line due to the cyclic loading from the effective stress path and the stress-strain behavior. It may be related to decreasing of bearing capacity induced by the reduction of effective stress caused by the increase of the excess pore water pressure.