• Journal of the Korean Geosynthetics Society
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• v.18 no.4
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• pp.75-85
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• 2019

The lateral load from traffic depends on standard truck's axle loads and locations, loading distance from the inner wall. The method of limit state design has been adopted and used for design of roads in the Republic of Korea since 2015. The concept of equivalent height of soil accounting for traffic loading is often used for design of retaining walls to quantify the traffic loads transmitted to the inner wall faces. Due to the different characteristics of the standard design trucks between Korea and US (AASHTO), the direct use of the guidelines from AASHTO LRFD leads to incorrect estimation of traffic load effects on retaining walls. This paper presents the results of evaluation of equivalent height of soil to reflect the standard truck of the nation, based on the findings from analytical solutions using 3D finite element method. Compare to US, the standard truck loading has a structure where the axle load is concentrated so that the equivalent load height is estimated to be slightly larger than AASHTO for lower retaining wall height. It would be reasonable to present the equivalent load height in Korea more conservatively than AASHTO in terms of securing long term stability of the retaining wall structure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.366-376
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• 2017

This study attempts to analyze the structure of the knowledge and duties of the vocational counseling service industry by using the text mining method and network analysis, which are methods of big data analysis. The subjects of the survey were vocational counseling, job placement and career change support, three fields in the unit elements of competence included in the National Competency Standards (NCS) which areproposed by the government. Although the analysis results of frequently used words showed that all three fields had independent duties, many were overlapping, such as counseling, examination, employment support, etc. for clients, job seekers, and others. The knowledge required by the employees of this field includes many new fields, such as start-up development, lifelong career consulting, job adaptation and culture conflict, besides the five subjects of vocational psychology, vocational counseling, labor market, job information, and law, which are included in the vocational counselor certification examination. Also, we suggested that the consultants adhere to emotional approaches, such as empathy, acceptance and attentiveness, and take a neutral stance. This study isvaluable in that it is the first attempt to objectively analyze the duties of the vocational counseling service field by big data analysis. In addition, it is also meaningful that we first confirmed the difference between the direction of government policy and the actual practice in the field.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.6
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• pp.369-381
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• 2017

It has been presumed that highly nonlinear skewed waves frequently observed in a surf zone could significantly influence the transmission behaviour via a porous wave breaker due to its larger inertia force than its nonlinear counterparts of zero skewness [Cnoidal waves]. In this study, in order to confirm this perception, a numerical simulation has been implemented for 6 waves the skewness of that range from 1.02 to 1.032. A numerical simulation are based on the Tool Box called as the ihFoam that has its roots on the OpenFoam. Skewed waves are guided by the shoal of 1:30 slope, and the flow in the porous media are analyzed by adding the additional damping term into the RANS (Reynolds Averaged Navier-Stokes equation). Numerical results show that the highly nonlinear skewed waves are of higher transmitted ratio than its counterparts due to its stronger inertia force. In this study, in order to see whether or not the damping at the porous structure has an effect on the wave celerity, we also derived the dispersive relationships of Nonlinear Shallow Water Eq. [NSW] with damping at the porous structure being accounted. The newly derived dispersive relationships shows that the phase lag between the damping friction and the free surface elevation due to waves significantly influence the wave celerity.

• Journal of the Korean Geosynthetics Society
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• v.17 no.1
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• pp.111-118
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• 2018

In case of excavation of the tunnel under weak ground conditions, such as fault zone, leg pile reinforcement with the purpose of suppressing tunnel crown settlement and side wall displacement is commonly applied. There are convergence, crown settlement, leg settlement, and the axial force of leg as a main factor for confirming the safety of support considering the installation angle and length of leg pile reinforcement according to the increase in rate of change of tunnel cross-section. In particular, the influence of right corner settlement, among variables for safety confirmation during excavation, has been analyzed as the dominant factor in the most important priority management showing larger displacement tendency than the increase in rate of the cross-section. And, it was analyzed that the occurrence tendency of axial force on leg pile reinforcement showed the influence of behavior according to the friction support concept mechanism of the pile reinforcement rather than the increase in rate of tunnel cross-section, as it showed a small increase compared to the increase rate of the tunnel cross-section which did not show a great correlation from the viewpoint of the change of the axial force by the length of each leg pile reinforcement with regards to the change in rate of increase in tunnel cross-section. If a certain length of the leg pile reinforcement is selected based on the above grounds, even if the cross-section of the tunnel in poor ground condition is somewhat larger, it has been proved to be a more reasonable method considering the workability and economical efficiency by not extending the length of the leg pile reinforcement by force.

• Journal of Digital Convergence
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• v.13 no.4
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• pp.127-135
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• 2015

This study was carried out to verify management commitment on perceived consulting quality in the government-supported convergence consulting service on SMEs. A survey was conducted and analyzed on SMEs which went through government-supported consulting, with the following results of the study. First, management commitment was found to have positive effect on the perceived consultant perform quality. Second, management commitment was found to have positive effect on the perceived government support quality. Third, management commitment was found to have no effect on the perceived consulting results quality. Fourth, perceived consultant perform quality was found to have positive effect on the perceived consulting results quality. Fifth, perceived government support quality was found to have positive effect on the perceived consulting results quality. Suggestions and significance of this study are as follows: the result of this study suggests a need to increase institutional support for enhancing the management commitment as well as the capability of consultants and support of government. It also has significance in presenting an effective and efficient direction of policy on consulting support project for SMEs.

• Information Systems Review
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• v.8 no.1
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• pp.63-80
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• 2006

This paper suggests a normative performance measurement model for B2B e-marketplace. The model is for the neutral and systematic sourcing B2B e-marketplace. It is based on BSC that is very powerful and sound tool among all the available performance measurement systems. In addition, we used AHP to make the model more structured and to draw weights of performance measures from experts. We derived main features and factors affecting performance of e-business companies and especially of B2B e-marketplaces based on literature. In order to make the model usefulness, we co-worked with some experts who are engaged in real Korean B2B e-marketplaces. They included venture capitalists, top managers of B2B e-marketplaces, and consultants. By their assistances, we could find important evaluating factors and define the hierarchical structure. After defining the hierarchical structure, the expert group decided weights of performance indicators through the designed questionnaires. The weight for each measure was calculated using geometric mean of the questionnaire response. We made the case studies of two real Korean B2B e-marketplaces to apply the suggested model with some adjustments. The results of the case studies were so satisfactory that the suggested performance measurement model for B2B e-marketplace is useful and applicable to the real world.

• Journal of Korea Water Resources Association
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• v.43 no.12
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• pp.1011-1027
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• 2010

In hydrologic modeling, prediction uncertainty generally stems from various uncertainty sources associated with model structure, data, and parameters, etc. This study aims to assess the parameter uncertainty effect on hydrologic prediction results. For this objective, a distributed rainfall-sediment yield-runoff model, which consists of rainfall-runoff module for simulation of surface and subsurface flows and sediment yield module based on unit stream power theory, was applied to the mesoscale mountainous area (Cheoncheon catchment; 289.9 $km^2$). For parameter uncertainty evaluation, the model was calibrated by a multi-objective optimization algorithm (MOSCEM) with two different objective functions (RMSE and HMLE) and Pareto optimal solutions of each case were then estimated. In Case I, the rainfall-runoff module was calibrated to investigate the effect of parameter uncertainty on hydrograph reproduction whereas in Case II, sediment yield module was calibrated to show the propagation of parameter uncertainty into sedigraph estimation. Additionally, in Case III, all parameters of both modules were simultaneously calibrated in order to take account of prediction uncertainty in rainfall-sediment yield-runoff modeling. The results showed that hydrograph prediction uncertainty of Case I was observed over the low-flow periods while the sedigraph of high-flow periods was sensitive to uncertainty of the sediment yield module parameters in Case II. In Case III, prediction uncertainty ranges of both hydrograph and sedigraph were larger than the other cases. Furthermore, prediction uncertainty in terms of spatial distribution of erosion and deposition drastically varied with the applied model parameters for all cases.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.09a
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• pp.155-175
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• 2005

Soil and rock dynamic properties such as shear wave velocity (VS), compressional wave velocity (VP) and corresponding Poisson's ratio ( v ) are very important geotechnical parameters in predicting deformational behavior of structures as well as practicing seismic design and performance evaluation. In an effort to measure the parameter efficiently and accurately, various bore-hole seismic testing techniques have been, thus, developed and used during past several decades. In this study, cross-hole seismic testing technique which is known as the most reliable seismic method was adopted for obtaining geotechnical dynamic properties. To perform successfully the cross-hole test for rock as well as soil layers regardless of the ground water level, spring-loaded source which impact laterally a subsurface ground in vertical bore-hole was developed and applied at three study areas, which contain four sites composed of two existing port sites and two new LNG storage facility sites. The geotechnical dynamic properties such as VS, VP and v with depth were efficiently determined from the laterally impacted cross-hole seismic tests at study sites, and were provided as the fundamental parameters for the seismic performance evaluation of the existing ports and the seismic design of the LNG storage facilities.

• Journal of Gifted/Talented Education
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• v.13 no.2
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• pp.95-112
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• 2003

The purpose of this study is to look into Various educational supports for the gifted students in science to decide proper career planning through Research of Career Consciousness of the Gifted Students in Science. The subject of this study is new students entered into KAIST from the year of 1996 to 2003. They are approximately 500 students yearly and 3,613 totally and more than 90% of students have answered. The Questions are largely 3 items. One is 5 Q's of entering universities, second is 2 Q's of life plans in the university and the last is 2 Q's of career plans after graduation. As a result, the gifted students in science tend to find out and develop their interest and aptitude early and decide their future much earlier than other students. Nevertheless the gifted students in science worry about their future a lot as well. However they ask their problems to friends, seniors, and parents rather than teachers, professional consultants in general it could say no sufficient systematic guidance and consulting available for them. So it does require that some subjects such as guidance for career planning should be included in university curriculum and furthermore not only schooling but also the systematic structure of persistent consulting about gifted student's general life should be planned as well.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.62-68
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• 2013

The effect of organic substance on its degradation rate in burial site was investigated using batch tests. Substrate were swine and cattle with the initial concentrations of 2, 4, 6, 8, and 10 g VS(volatile solids)/L, respectively. The highest methane production rates of swine and cattle were found at 2 g VS/L as 46.3 and 48.4 ml CH4/g VS.d, respectively. As substrate concentration increased, the methane production rate decreased. The inhibition constants were n and m that were estimated using nonlinear inhibition model. The values of n and m were inhibition constants of methane production rate and ultimate methane yield, respectively. The values of n and m were 4.9 and 0.6 on swine and 1.1 and 0.4 on cattle. The methane production rate was responded sensitively by increase and decrease of substrate concentration, whereas ultimate methane yield do not relatively. From a relation between n and m, inhibitory effect of substrate concentration was confirmed as uncompetitive inhibition.