• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3_1spc
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• pp.489-495
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• 2013

This study analyzed thevariation in the cutting force when the cutting area of a terrace volume is machined, which is generally left after the rough cutting of a sculptured surface. The numerically simulated results for the cutting forces are compared with cutting force measurements by considering the theoretical prediction of the cutting area formation and specific cutting volume. The variation in the cutting force is measured using a dynamometer installed on a machining center for 19 different kinds of test pieces, which are selected according to the variation in the terrace volume factor, tool diameter factor, and cutting depth factor. As a result, it is verified that the cutting forces evaluated by the numerical analysis coincide with the measured cutting forces, and it is proposed as a practical cutting force prediction model.

• Health Policy and Management
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• v.23 no.4
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• pp.343-348
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• 2013

Background: Price control alone may not successfully restrain growth in health expenditures. This study aimed to propose fee adjustment model suitable for Korea reflecting health service volume and to clarify applicability of the model by comparing actual conversion factor with estimated conversion factor from simulation of this model. Methods: Fee adjustment model was developed based on Alberta's fee adjustment formula in Canada and 7 alternatives were assessed according to diversely applied parameters of the model. Results: Estimated conversion factors of the tertiary care hospital and the hospital were lower than actual conversion factors, since the utilization of heath service has been increased. However, there was no big difference between estimated conversion factors and actual conversion factors of the general hospital and the clinic. Eventually this fee adjustment model could estimate proper conversion factor reflecting health service volume. Conclusion: This model may be applicable to the mechanism as determining conversion factor between insurer and provider via negotiation and controling growth in health expenditures.

• Journal of Mechanical Science and Technology
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• v.15 no.9
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• pp.1217-1225
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• 2001

The governing equations are derived for the analysis of a stepped labyrinth gas seal generally used in high performance compressors, gas turbines, and steam turbines. The bulk-flow is assumed for a single cavity control volume set up in a stepped labyrinth cavity and the flow is assumed to be completely turbulent in the circumferential direction. The Moodys wall-friction-factor model is used for the calculation of wall shear stresses in the single cavity control volume. For the reaction force developed by the stepped labyrinth gas seal, linearized zeroth-order and first-order perturbation equations are developed for small motion about a centered position. Integration of the resultant first-order pressure distribution along and around the seal defines the rotordynamic coefficients of the stepped labyrinth gas seal. The resulting leakage and rotordynamic characteristics of the stepped labyrinth gas seal are presented and compared with Scharrers theoretical analysis using Blasius wall-friction-factor model. The present analysis shows a good qualitative agreement of leakage characteristics with Scharrers analysis, but underpredicts by about 20%. For the rotordynamic coefficients, the present analysis generally yields smaller predictied values compared with Scharrers analysis.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.3
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• pp.29-37
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• 2008

In this parer, we purpose for applying the RFID(Radio Frequency IDentification) system in National Road Traffic Volume Survey. Because there is limitation for shipping RFID Tag on every car, we firstly defined Expansion (process of making the number of all cars which passed survey point from sampling data) and determined the best methodology among 3 methodologies (Time factor Model, Fuzzy Model, Artificial Neural Network). As a result of analysis, Time Factor Model was chosen as the best methodology for Expansion. Also, we analyzed to find an application of the RFID system in National Road Traffic Volume Survey and obtained a possibility applying it. It is expected that if the RFID system is used in Traffic Volume Survey, the survey cost is saved than before.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.6
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• pp.3-14
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• 2018

The aim of this study is to propose a method for calculating the weight of walking energy in ERAM model by calculating it for the analysis of vertical and horizontal spaces in a building. Conventional theories on the space analysis in the field of architectural planning predict the pedestrian volume of network spaces in urban street or in two-dimensional plane within a building, however, for vertical and horizontal spaces in a building, estimates of the pedestrian volume by those theories are limited. Because in the spatial syntax and ERAM model have been applied weights such as the spatial depth, adjacent angles, and physical distances available only to the two-dimensional same layer or plane. Therefore, the following basic assumptions and analysis conditions in this study were established for deriving a predictor of pedestrian volume in vertical and horizontal spaces of a building. The basic premise of space analysis is not to address the relationship between the pedestrian volume and the spatial structure itself but to the properties of spatial structure connection that human beings experience. The analysis conditions in three-dimensional spaces are as follows : 1) Measurement units should be standardized on the same scale, and 2) The connection characteristics between spaces should influence the accessibility of human beings. In this regard, a factor of walking energy has the attributes to analyze the connection of vertical and horizontal spaces and satisfies the analysis conditions presented in this study. This study has two implications. First, this study has shown how to quantitatively calculate the walking energy after a factor of walking energy was derived to predict the pedestrian volume in vertical and horizontal spaces. Second, the method of calculating the walking energy can be applied to the weights of the ERAM model, which provided the theoretical basis for future studies to predict the pedestrian volume of vertical and horizontal spaces in a building.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.155-162
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• 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 Mechanical Science and Technology
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• v.16 no.4
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• pp.564-571
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• 2002

Three-dimensional numerical analysis of the turbulent premixed flame propagation in a constant volume combustion chamber is performed using the KIVA-3V code (Amsden et. al. 1997) by the flame surface density (FSD) model. A simple near-wall boundary condition is eaployed to describe the interaction between turbulent premixed flame and the wall. A mean stretch factor is introduced to include the stretch and curvature effects of turbulence. The results from the FSD model are compared with the experimental results of schlieren photos and pressure measurements. It is found that the burned mass rate and flame propagation by the FSD model are in reasonable agreement with the experimental results. The FSD combustion model proved to be effective for description of turbulent premixed flames.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.5
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• pp.253-263
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• 2021

Traffic data collected using advanced equipment are highly valuable for traffic planning and efficient road operation. However, there is a problem regarding the reliability of the analysis results due to equipment defects, errors in the data aggregation process, and missing data. Unlike other detectors installed for each vehicle lane, radar detectors can yield different error types because they detect all traffic volume in multilane two-way roads via a single installation external to the roadway. For the traffic data of a radar detector to be representative of reliable data, the error factors of the radar detector must be analyzed. This study presents a field survey of variables that may cause errors in traffic volume collection by targeting the points where radar detectors are installed. Video traffic data are used to determine the errors in traffic measured by a radar detector. This study establishes three types of radar detector traffic errors, i.e., artificial, mechanical, and complex errors. Among these types, it is difficult to determine the cause of the errors due to several complex factors. To solve this problem, this study developed a radar detector traffic volume error analysis model using a multiple linear regression model. The results indicate that the characteristics of the detector, road facilities, geometry, and other traffic environment factors affect errors in traffic volume detection.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.287-299
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• 2014

Bicarbonate anion ($HCO_3{^-}$) takes the role of major buffer systems in our body by maintaining the pH at 7.4. Epithelial $HCO_3{^-}$ secretion also hydrolyzes the mucus which protects body from noxious infections. It has been widely known that such infections are closely related to $HCO_3{^-}$ permeability through membrane and, thus, increasing the $HCO_3{^-}$ permeability is essential. To evaluate the $HCO_3{^-}$ permeability through ion channels, the free energy changes relevant to ion pumping are calculated with the Integral Equation Formalism-PCM (IEF-PCM) theory. Molecular structures of various anions including $HCO_3{^-}$ were optimized with the density functional theory at the level of B3LYP/6-311++G(d,p) in gas and solution phase. In addition, the anion permeability is significantly influenced by the relative size of the anion and pore. We introduce a shifted volume factor model that describes the pore size effect when the charged solutes transfer through ion channels. We found excellent agreement between experimental and calculated permeability when our novel model of the size effect was taken into account to.

• Journal of the Korean Society of Safety
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• v.32 no.1
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• pp.128-133
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• 2017

This study deals with the roundabout traffic accidents by traffic impeding factor. The purpose of this study is to comparatively analyze the characteristics of accidents and to develop the accident models. In pursuing the above, this study used a statistical program SPSS 20.0 to analyze 2,342 accidents occurred within 79 roundabouts in Korea. The main results are as follows. First, 4 accident models which were all statistically significant were developed. Second, the traffic volume and width of right-turn-only lane were analyzed to be common variable in the bus stop related models. The variables such as right-turn-only lane, street light, turning radius of entry lane were selected as specific variables. Especially street light and turning radius of entry lane were evaluated to have negative effects to the accidents. It is, therefore, essential to install the street light and place a sufficient turning radius in order to reduce the roundabout accidents. Finally, the traffic volume and number of entry lane were analyzed to be common variable in the on-street parking related models. Also, the width of right-turn-only lane and bus stop were evaluate to be specific variables in the model with on-street parking. This can be expected to give some implications to making the accident reduction guidelines.