• Journal of Technologic Dentistry
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• v.41 no.4
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• pp.287-293
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• 2019

Purpose: To evaluate the accuracy of the 3D printed die models and to investigate its clinical applicability. Methods: Stone die models were fabricated from conventional impressions(stone die model; SDM, n=7). 3D virtual models obtained from the digital impressions were manufactured as a 3D printed die models using a 3D printer(3D printed die models;3DM, n=7). Reference model, stone die models and 3D printed die models were scanned with a reference scanner. All dies model dataset were superimposed with the reference model file by the "Best fit alignment" method using 3D analysis software. Statistical analysis was performed using the independent t-test and 2-way ANOVA (α=.05). Results: The RMS value of the 3D printed die model was significantly larger than the RMS value of the stone die model (P<.001). As a result of 2-way ANOVA, significant differences were found between the model group (P<.001) and the part (P<.001), and their interaction effects (P<.001). Conclusion: The 3D printed die model showed lower accuracy than the stone die model. Therefore, it is necessary to further improve the performance of 3D printer in order to apply the 3D printed model in prosthodontics.

• Journal of the Korean Data and Information Science Society
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• v.19 no.3
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• pp.893-901
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• 2008

The disconfirmation paradigm is the earliest researched and the most deeply researched of all the paradigms in marketing. Disconfirmation paradigm deals with the influence of expectation, perceived product performance, and the discord between the two on consumer satisfaction. The GAP-Model is based on the disconfirmation paradigm that tries to understand the effect of the gap between before purchase expectations and after purchase perceptions of the product performance on dependent variables such as customer satisfaction. The purpose of this research is to test whether regression coefficients of a P-Model(performance only model), an E-Model(expectation only model) and GAP(P-E)-Model are equivalent in explaining service value and loyalty. The Chow's F-Test is used to test the excellence of the 3 models. As a result of comparison and analysis, P-Model showed more excellence of service value and loyalty than E-Model or GAP-Model.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.3
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• pp.109-124
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• 2016

The objective of this paper is to find the density, stiffness, and strength of truss-wall diamond corrugation model combined with pinwheel truss inside space. The truss-wall diamond corrugation (TDC) model is defined as a unit cell coming from solid-wall diamond corrugation (SDC) model. Pinwheel truss-wall diamond corrugation (P-TDC) model is made by TDC connected with pinwheel structure inside of the space. Derived ideal solutions of P-TDC is based on truss-wall and pinwheel truss model at first. And then it is compared with Gibson-Ashby's ideal solution. To validate the ideal solutions of the P-TDC, ABAQUS software is used to predict the density, strength, and stiffness, and then each of them are compared to the ideal solution of Gibson-Ashby with a log-log scale. Applied material property is stainless steel 304 because of having cost effectiveness. Applied parameters for P-TDC are 1 thru 5 mm diameter within fixed opening width as 4mm. In conclusion, the relative Young's modulus and relative yield strength of the P-TDC unit model is reasonable matched to the ideal expectations of the Gibson-Ashby's theory. In nearby future, P-TDC model is hoped to be applied to make sandwich core structure by advanced technologies such as 3D printing skills.

• Nutrition Research and Practice
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• v.16 no.2
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• pp.205-216
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• 2022

BACKGROUND/OBJECTIVES: While many obesity studies have pointed out the importance of meal regularity, few have conducted empirical analyses using data from food diaries. We examined the association between meal regularity (i.e., meal time regularity [MTR] and calorie intake regularity [CIR]) and weight loss. SUBJECTS/METHODS: We collected food diary data from 637 women who had participated in commercial weight loss programs for 28-168 days (4-24 weeks). This study defined "meal regularity" in terms of two concepts: MTR and CIR. MTR refers to how regularly people eat their meals (i.e., at certain times each day), whereas CIR refers to how regularly people consume a certain amount of calories at each meal. We conducted multiple regression analyses. RESULTS: MTR (model 1: β = -2,576.526, P < 0.001; model 2: β = -1511.447, P < 0.05; model 3: β = -1,721.428, P < 0.05) and CIR (model 1: β = -1,231.551, P < 0.01; model 2: β = -2,082.353, P < 0.001; model 3: β = -1,343.490, P < 0.01) turned out to be significant determinants of the amount of weight loss in breakfast, lunch, and dinner contexts. While meal regularity (i.e., MTR and CIR) was significantly associated with weight loss, daily calorie intake from meals was not significantly associated with the amount of weight loss (model 1: β = 0.13, P > 0.05; model 2: β = 0.11, P > 0.05; model 3: β = 0.14, P > 0.05). Subjects who consumed an equal amount of calories per meal throughout the day lost more weight than those who did not (model 4: β = -3,675.51, P < 0.001). CONCLUSIONS: Eating each meal (i.e., breakfast, lunch, and dinner) at a certain time every day may increase weight loss success. Also, consuming the same amount of calories at each meal may help weight loss success.

• Journal of Radiation Protection and Research
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• v.17 no.1
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• pp.21-30
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• 1992

The frequencies of KCCH cyclotron neutron (30 cGy/min) or $^{60}Co\;{\gamma}-rays$ (210 cGy/min)-induced asymmetrical interchanges (dicentrics and centric rings) and acentric fragments (deletion) at several doses were measured in the normal human peripheral blood lymphocytes Chromosome aberrations were scored at the first nitosis after stimulation with phytohemagglutinin. The neutron and y-ray data were analysed on linear, power-law, quadratic and linear-quadratic model . When the dicentrics and centric rings of ${\gamma}-rays$ datas were pooled and fitted to these model, good fits were obtained to power-law $[Y=(5.81{\pm}1.96){\times}10^6D^{1.93+0.06},\; P=0.931]$, quadratic $[Y=(3.91{\pm}0.09){\times}10^{-6}D^2,\;P=0.972]$ an linear-Quadrati model $[Y=(6.55{\pm}6.83){\times}10^{-5}D+(3.72{\pm}0.22){\times}10^{-6}D^2\; P=0.922]$, except for linear model (P=0.067) As in the case of neutron data, the best fit was obtained to the linear model $(Y=(6.12{\pm}0.17){\times}10^{-3}\;D-0.22,\;P=0.987]$ and good fits were obtained to power-law$[Y=(5.36{\pm}3.02) {\times}10^{-4}D^{1.42+0.11},\; P=0.601]$ and linear-quadratic model$[Y=(2.43{\pm}0.70){\times}10^{-3}D+(1.21{\pm}0.39){\times}10^{-7}D^2$, \;P=0.415], except for quadratic model (P<0.005). The relative biological effectiveness (RBE) of neutron compared with y-ray was estimated by best fitting model. In the asymmetrical interchanges range between 0.1 and 1.5 per cell, the RBE was found to be $2.714{\pm}0.408$.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2004.05a
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• pp.395-400
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• 2004

This study is that STEP based Data Repository of APR1400 Nuclear Power Plant Reactor Coolant System is developed. The STEP based Data Repository is accessed by Web-based and an attribute data of Reactor Coolant System Equipment is offered. Also, a P&ID drawing file & 3D CAD Model of Reactor Coolant System is loaded. The P&ID drawing file of Reactor Coolant System Equipment Model is connected with 3D CAD Model file. This 2D/3D CAD Model connected Prototype system confirms a real layout of Reactor Coolant System.

• Proceedings of the Korea Concrete Institute Conference
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• 1992.10a
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• pp.140-154
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• 1992

The objective of the research stated here was aimed at providing the information needed to establish the Korean Seismic Design Code Recommendations and Guides for precast concrete (P.C) large panel apartment buildings. This was accomplished by investigation and analysis of the response of P.C large panel structures subjected to shaking table excitation simulating earthquake ground motion. one of the test specimens used was 1/3-scaled 3-story box P.C model provided by Sam-Hwan Camus Corporation. The 4m $\times$4m shaking table was used to simulate the earthquake ground motion. the employed input accelerogram was the one recorded as Taft N21E component and the peak ground acceleration(PGA) was scaled depending on the desired level of seismic severity and the time according to dynamic similitude rule. Based on results obtained from shaking table test of this P.C model, the following conclusions were drawn . (1) As far as test specimen is concerned, the seismic safety factors turns out to be 7~8. (2)P.C model has damping ratio of about8% which is twice larger than in-situ R.C. structure. And (3)this model has global displacement ductility ratio of 2~3 through the energy dissipation by opening and sliding of joints.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.1
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• pp.14-28
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• 2007

This study presented the selection of ozone ($O_3$) potential factors and designed and assessed its potential prediction model using multiple-linear regression equations in Ulsan area during the springtime from April to June, $2000{\sim}2004$. $O_3$ potential factors were selected by analyzing the relationship between meterological parameters and surface $O_3$ concentrations. In addition, cluster analysis (e.g., average linkage and K-means clustering techniques) was performed to identify three major synoptic patterns (e.g., $P1{\sim}P3$) for an $O_3$ potential prediction model. P1 is characterized by a presence of a low-pressure system over northeastern Korea, the Ulsan was influenced by the northwesterly synoptic flow leading to a retarded sea breeze development. P2 is characterized by a weakening high-pressure system over Korea, and P3 is clearly associated with a migratory anticyclone. The stepwise linear regression was performed to develop models for prediction of the highest 1-h $O_3$ occurring in the Ulsan. The results of the models were rather satisfactory, and the high $O_3$ simulation accuracy for $P1{\sim}P3$ synoptic patterns was found to be 79, 85, and 95%, respectively ($2000{\sim}2004$). The $O_3$ potential prediction model for $P1{\sim}P3$ using the predicted meteorological data in 2005 showed good high $O_3$ prediction performance with 78, 75, and 70%, respectively. Therefore the regression models can be a useful tool for forecasting of local $O_3$ concentration.

• Journal of Environmental Science International
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• v.12 no.7
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• pp.689-695
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• 2003

The purpose of this study is to evaluate and to predict of eutrophication in lakes by using Vollenweider-OECD model and total phosphorus concentration and inflow rate which were measured in 1993∼2001. The results of study were as follows. The annual total phosphorus loading from the watershed was calculated to be 55∼195tP/yr at lake Soyang, 221∼466tP/yr at lake Taechong, 123∼278tP/yr at lake Andong, 57∼109tP/yr at lake Seomjin. These are discharged, far the most parts, from population and fishfarm facility. TP loading on the surface area at lake Soyang was 3.01gP/㎡/yr, 2.82gP/㎡/yr, 2.84gP/㎡/yr, 3.03gP/㎡/yr, 2.34gP/㎡/yr, 1.78gP/㎡/yr, 0.91gP/㎡/yr, 0.89gP/㎡/yr, 0.86gP/㎡/yr, lake Taechong was 6.71gP/㎡/yr, 7.25gP/㎡/yr, 7.24gP/㎡/yr, 6.53gP/㎡/yr, 6.50gP/㎡/yr, 7.06gP/㎡/yr, 7.04gP/㎡/yr, 4.05gP/㎡/yr, 3.44gP/㎡/yr and TP loading on the surface area of lake Andong, lake Soemjin were 5.39gP/㎡/yr, 4.47gP/㎡/yr, 4.56gP/㎡/yr, 4.45gP/㎡/yr, 3.33gP/㎡/yr, 2.38gP/㎡/yr, 2.53gP/㎡/yr, 2.46gP/㎡/yr, 2.54gP/㎡/yr, 4.09gP/㎡/yr, 4.10gP/㎡/yr, 3.98gP/㎡/yr, 3.73gP/㎡/yr, 2.80gP/㎡/yr, 3.46gP/㎡/yr, 3.22gP/㎡/yr, 2.19gP/㎡/yr, 2.13gP/㎡/yr respectively. The tropic states of four lakes can be assessed as eutrophy because phosphorus leading exceeds the critical phosphorus loading by Vollenweider-OECD model.

• Korean Security Journal
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• no.37
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• pp.137-163
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• 2013

This research will incorporate cases from U.S public schools to analyze the factors which influences the security within the school and efficient security patterns to suggest an adequate suggestion to elevate domestic school security system. This study is divided into two following models: a serious criminal offense model, which considers crimes occurred on campus as subordinate variables, and a school violence model, which considers as subordinate variables after limiting an act of delinquency and an a group action that can harm the safety of students, although they are not included in the categories of crimes. First, from analyzing the factors which influences security within school, the explanation power of serious crime offense safety model and school violence safety model is measured 12% and 11.3%. In serious crime offense safety model, the safety education for students, among the safety programs provided by schools(t=2.548, p=0.011), parent participation to school management(t=10.694, p=0.000), Security activities on campus(t=3.643, p=0.000), and CPTED activity(t=6.467, p=0.000) are statistically significant, as affecting factors on the safety from serious crimes. Similarly in school violence model, the safety education for students, among the safety programs provided by schools(t=3.228, p=0.001), parent participation to school management(t=12.034, p=0.000), security activities on campus(t=2.663, p=0.000), and CPTED activity(t=3.928, p=0.000) are statistically significant, as affecting factors on the safety from school violence. Second, according to the analytic results on figuring out the optimal pattern to heighten the security activities, the serious offence model's explanatory power was 4.4% and school violence safety model rated 3.9%. With the serious offense safety model, the activity factors which showed statistically significant in influencing safety from serious offenses were cooperation with local police force (t=2112, p=0.035), school policy management (t=3.309, p=0.001), security patrolling activity (t=2.548, p=0.011). In the school violence model, security activities initiated by the school which showed statistically significant from serious offenses were cooperation with local police force (t=2.364, p=0.018) and policy management (t=4.142, p=0.000). In accordance with the result of this study, education for students rather than education for teachers is more positive in terms of the safety on campus, and parent participation, like education, is consistently needed for the safety on campus. In case of CPTED activity, reinforcing plans should be prepared by intactly accepting examples in the USA. In case of security activity, plans that can increase visibility and reinforce cooperation with local police in a smooth way will provide a positive effect to the safety on campus.