• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.2D
• /
• pp.155-162
• /
• 2008

This study shows how to estimate the design hour factor when the counting stations don't have all of the hourly volumes such as in a coverage survey. A coverage survey records traffic volume from 1 to 5 times in a year so it lacks the detailed information to calculate the design hour factor. This study used the traffic volumes of permanent surveys to estimate the design hour factor in coverage surveys using correlation and regression analysis. A total 7 independent variables are used : the coefficient of variance of hourly volume, standard deviation of hourly volume, peak hour volume, AADT, heavy traffic volume proprotion, day time traffic volume proportion and D factor. All of variables are plotted on a curve, so it must use non-linear regression to analyze the data. As a result the coefficient of determination and MAE are good at logarith model using AADT.

• Journal of Korean Institute of Industrial Engineers
• /
• v.32 no.1
• /
• pp.18-28
• /
• 2006

Some issues which should be considered in an R&D project selection problem are as follows: First, quantitative analysis on the efficiencies of R&D projects is required to guarantee objective validity in the evaluation of the projects. For this reason, the methodology for selecting R&D projects should be based on mathematical models that perform quantitative analysis. Second, in general there are ordinal factors like Likert-scale in the data for evaluating R&D projects. Previous researches, however, couldn't suggest explicit methods incorporating these ordinal factors into models. Third, for the R&D project selection problems with limited resources like budget, it is necessary to decide the perfect ranking of the all projects. This paper develops a mathematical model that can be applicable to the problems of selecting R&D projects with the previous features. In this paper, we improve the original DEA model for evaluating efficiency to incorporate ordinal factors and suggest a new model which can decide the perfect ranking of all projects by merging the improved DEA model and AHP method. Furthermore a web-based R&D project selection system using the DEA/AHP model suggested in this paper is developed and illustrated.

• The Journal of Korea Robotics Society
• /
• v.13 no.3
• /
• pp.174-181
• /
• 2018

For a mobile robot that travels along a terrain consisting of various geology, information on tire force and friction coefficient between ground and wheel is an important factor. In order to estimate the lateral force between ground and wheel, a lot of information about the model and the surrounding environment of the vehicle is required in conventional method. Therefore, in this paper, we are going to estimate lateral force through simple model (Minimal Argument Lateral Slip Curve, MALSC) using only minimum data with high estimation accuracy and to improve estimation reliability of the friction coefficient by using the estimated lateral force data. Simulation is carried out to analyze the correlation between the longitudinal and transverse friction coefficients and slip angles to design the simplified lateral force estimation model by analysing simulation data and to apply it to the actual field environment. In order to verify the validity of the equation, estimation results are compared with the conventional method through simulation. Also, the results of the lateral force and friction coefficient estimation are compared from both the conventional method and the proposed model through the actual robot running experiments.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.21 no.9
• /
• pp.805-812
• /
• 2011

This study investigated the characteristics of heavy-weight floor impact sounds of box-frame type structure using 1:10 scale model. Ten types of floor structures(bare slabs and floating floors) were evaluated in terms of dynamic stiffness and loss factor. Floor vibrations and radiated sounds generated by simulated impact source were also measured. The results showed that the bakelite was appropriate for simulating concrete slab in the 1:10 scale model, and surface velocity and sound pressure level of concrete slab measured from the scale model showed similar tendencies with the results from in-situ in frequency domain. It was also found that dynamic behaviors of layered floor structures in the 1:10 scale model were similar to those in a real scale. Therefore, the use of 1:10 scale model would be useful for evaluating the heavy-weight floor impact sound insulation of layered floor structures when the frequency-dependent dynamic properties of each material are known.

• Journal of Korean Library and Information Science Society
• /
• v.41 no.1
• /
• pp.121-147
• /
• 2010

The purpose of this study is to develop and prove service quality measurement model and indicators which are able to measure objectively service quality of digital libraries in Korea. Literature review and Delphi survey are used to investigate service quality dimensions. User perceived service quality performance was measured to validate DL-SQI model with three digital libraries. Finally DL-SQI(Digital Library-Service Quality Index) model was developed which is composed of four primary dimensions. The survey results reveal that reliability coefficient is 0.8 which means high reliability of survey and it suggests that DL-SQI model based on the above dimensions is proved through confirmatory factor analysis.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.28 no.4
• /
• pp.155-189
• /
• 2003

In this research, the comprehensive evaluation model of IS(information systems) for public sectors is theoretically constructed through reviewing and integrating previous IS evaluation-related research. This model is hypothesized to consist of five sectors(System Sector, User Sector, Organization and Management Sector, Resource Management Sector and Strategic Contribution Sector), ten evaluation items belonging to these five evaluation sectors, and sixty two evaluation indices for these ten evaluation items. The results of empirical analyses to test the validity of the research model show that the evaluation sectors turn out to be the same ones as proposed in the hypothetical model. The evaluation items(System Quality, Information Quality, Service Quality) in System Sector proves to be consistent with the hypothetical model. However, in case of User Sector, two evaluation items(Perceived Usefulness and User Satisfaction) which are included in the hypothetical model are found to be merged into one item(User Satisfaction). And, it is shown that four evaluation items such as the Efficiency of Internal Process, Customer Satisfaction, Organizational Innovation, and the Degree of Informatization competence improvement are included in Organization and Management Sector, differently from the research model in which the items, Organizational innovation and the Degree of Informatization competence improvement, are not divided. As a final result, sixty two evaluation indices that comprise all the evaluation items belonging to five sectors are found to be reduced to fifty seven ones through factor analyses, criterion-related validity tests and reliability analyses.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.12
• /
• pp.5776-5785
• /
• 2012

Government bodies offer various policies and programs to support small and medium sized enterprise. There's no only one business firm's performance model for the management performance assessment for the government's supporting and/or resupporting program. However assessment factor had been supposed to manage for the enterprise. Current assessment standards, that is Business Innovation Small and Medium sized firm Certification Model, Technology Innovation Small and Medium sized firm Certification Model, Productivity Management System Certification Model, Small and Medium Sized Firms of Korea Federation of Banks, and Business Performance of the State Owned Enterprise would be collected and then develop performance assessment model for the start-ups small and medium sized firms.

• Journal of the Korean Society of Combustion
• /
• v.15 no.1
• /
• pp.22-29
• /
• 2010

In this study, carbon conversion was measured using an electronic mass balance. In a lab scale furnace, each coal sample was pyrolyzed in a nitrogen environment and became coal char, which was then gasified with steam under isothermal conditions. The reactivity of coal char was investigated at various temperatures and steam concentrations. The VRM(volume reaction model), SCM(shrinking core model), and RPM(random pore model) were used to interpret experimental data. For each model the activation energy(Ea), pre-exponential factor (A), and reaction order(n) of the coal char-steam reaction were determined by applying the Arrhenius equation into the data obtained with thermo-gravimetric analysis(TGA). According to this study, it was found that experimental data agreed better with the VRM and SCM for 1,000 and $1,100^{\circ}C$, and the RPM for 1,200 and $1,300^{\circ}C$. The reactivity of chars increased with the increase of gasification temperature. The structure parameter(${\psi}$) of the surface area for the RPM was obtained.

• Journal of Ecology and Environment
• /
• v.32 no.4
• /
• pp.229-236
• /
• 2009

A habitat model was developed to delineate potential habitat of the leopard cat (Prionailurus bengalensis) in a mountainous region of Kangwon Province, Korea. Between 1997 and 2005, 224 leopard cat presence sites were recorded in the province in the Nationwide Survey on Natural Environments. Fifty percent of the sites were used to develop a habitat model, and the remaining sites were used to test the model. Fourteen environmental variables related to topographic features, water resources, vegetation and human disturbance were quantified for 112 of the leopard cat presence sites and an equal number of randomly selected sites. Statistical analyses (e.g., t-tests, and Pearson correlation analysis) showed that elevation, ridges, plains, % water cover, distance to water source, vegetated area, deciduous forest, coniferous forest, and distance to paved road differed significantly (P < 0.01) between presence and random sites. Stepwise logistic regression was used to develop a habitat model. Landform type (e.g., ridges vs. plains) is the major topographic factor affecting leopard cat presence. The species also appears to prefer deciduous forests and areas far from paved roads. The habitat map derived from the model correctly classified 93.75% of data from an independent sample of leopard cat presence sites, and the map at a regional scale showed that the cat's habitats are highly fragmented. Protection and restoration of connectivity of critical habitats should be implemented to preserve the leopard cat in mountainous regions of Korea.

• Journal of Information Technology Applications and Management
• /
• v.16 no.4
• /
• pp.79-92
• /
• 2009

With the rising reliance on market estimation through customer analysis in customer-centered marketing, there is a rapid increase in the amount of personal data owned by corporations. There has been a corresponding rise in the customers' interest in personal information protection, and the problem of personal information leakage has risen as a serious issue. The purpose of this research is to develop a diagnosis model for personal information protection that is suited to our country's corporate environment, and on this basis, to present diagnostic instruments that can be applied to domestic corporations. This diagnosis model is a structural equation model that schematizes the degree of synthetic effect that administration factors and estimation items have on the protection of personal information owned by corporations. We develop the model- consisting of the administration factors for personal information protection and the measurement items of each factor- using the development method of standardized structural equation model. We then present a tool through which the administration factors and estimation items verified through this model can be used in the diagnosis for personal information protection in corporations. This diagnostic tool can be utilized as a useful instrument to prevent in advance the leakage of personal information in corporations.