• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.3
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• pp.231-242
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• 2008

Purpose: The purpose of this study was to investigate the bond strength of the core-veneer interface in all ceramic systems. Material and Methods: The all ceramic systems tested with their respective veneer were IPS Empress 2 with IPS Eris, IPS e.max Press with IPS e.max Ceram and IPS-e.max ZirCAD with IPS e.max Ceram. Cores (N=36, N=12/group, diameter: 10mm, thickness: 3mm) were fabricated according to the manufacturer's instruction and cleaned with ultrasonic cleaner. The veneer(diameter: 3mm, thickness: 2mm) were condensed in stainless steel mold and fired on to the core materials. After firing, they were again ultrasonically cleaned and embedded in acrylic resin. The specimens were stored in distilled water at $37^{\circ}C$ for 1 week. The specimens were placed in a mounting jig and subjected to shear force in a universal testing machine(Z020, Zwick, Germany). Load was applied at close to the core-veneer interface as possible with crosshead speed of 1.00mm/min until failure. Average shear bond strengths(MPa) were analyzed with a one-way analysis of variance and the Tukey test(${\alpha}=.05$). The failed specimens were examinated by scanning electron microscopy(JSM-6360, JEOL, Japan). The pattern of failure was classified as cohesive in core, cohesive in veneer, mixed or adhesive. Results: The mean shear bond strength($MPa{\pm}SD$) were IPS e.max Press $32.85{\pm}6.75MPa$, IPS Empress 2 $29.30{\pm}6.51MPa$, IPS e.max ZirCAD $28.10{\pm}4.28MPa$. IPS Empress 2, IPS e.max Press, IPS e.max ZirCAD were not significantly different from each others. Scanning electron microscopy examination revealed that adhesive failure did not occur in any all ceramic systems. IPS Empress 2 and IPS e.max Press exhibited cohesive failure in both the core and the veneer. IPS e.max ZirCAD exhibited cohesive failure in veneer and mixed failure.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.259-264
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• 2015

For this experiment, specimen was manufactured by injecting polymer and monomer into silicon mold with volume ratio of 2.5:1 based on ISO 20795-2 so that average thickness, width and length of specimen would be maintained as 3.3 mm, 10.0 mm and 65.0 mm, respectively depending on spray on technique. Specimen was divided into 3 groups ($25^{\circ}C$, $40^{\circ}C$, $70^{\circ}C$) depending on polymerization temperature and 10 specimen was manufactured for each group and it was polymerized in water tank of ${\pm}1^{\circ}C$ under the setting condition of polymerization time of 15 minutes and pressure of 3 bar. After keeping specimen in distilled water of $37^{\circ}C$ for over 48 hours before experiment, flexural strength (FS) and elasticity modulus (EM) of specimen being tested by using Intron (3344; Instron; Instron). SPSS ver. 16.0 was used for analysis and post-hoc test of Scheffe was performed after using one-way ANOVA. When comparing mean value of FS of resin for orthodontics, it was represented in the range of 71.500 MPa for $25^{\circ}C$ group, 74.920 MPa for $40^{\circ}C$ group and 76.880 MPa for $70^{\circ}C$ group and difference was shown in the order of $25^{\circ}C$ group <$40^{\circ}C$ group <$70^{\circ}C$ group but such difference was not significant statistically (p=0.052). Result of EM mean value of resin for orthodontics was more polymerization temperature was high, the more was significant difference represented in the order of $25^{\circ}C$ group <$40^{\circ}C$ group <$70^{\circ}C$ group (p<0.039).

• Journal of Intelligence and Information Systems
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• v.28 no.1
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• pp.263-286
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• 2022

This study acquires NBA statistical information for a total of 32 years from 1990 to 2022 using web crawling, observes variables of interest through exploratory data analysis, and generates related derived variables. Unused variables were removed through a purification process on the input data, and correlation analysis, t-test, and ANOVA were performed on the remaining variables. For the variable of interest, the difference in the mean between the groups that advanced to the playoffs and did not advance to the playoffs was tested, and then to compensate for this, the average difference between the three groups (higher/middle/lower) based on ranking was reconfirmed. Of the input data, only this year's season data was used as a test set, and 5-fold cross-validation was performed by dividing the training set and the validation set for model training. The overfitting problem was solved by comparing the cross-validation result and the final analysis result using the test set to confirm that there was no difference in the performance matrix. Because the quality level of the raw data is high and the statistical assumptions are satisfied, most of the models showed good results despite the small data set. This study not only predicts NBA game results or classifies whether or not to advance to the playoffs using machine learning, but also examines whether the variables of interest are included in the major variables with high importance by understanding the importance of input attribute. Through the visualization of SHAP value, it was possible to overcome the limitation that could not be interpreted only with the result of feature importance, and to compensate for the lack of consistency in the importance calculation in the process of entering/removing variables. It was found that a number of variables related to three points and errors classified as subjects of interest in this study were included in the major variables affecting advancing to the playoffs in the NBA. Although this study is similar in that it includes topics such as match results, playoffs, and championship predictions, which have been dealt with in the existing sports data analysis field, and comparatively analyzed several machine learning models for analysis, there is a difference in that the interest features are set in advance and statistically verified, so that it is compared with the machine learning analysis result. Also, it was differentiated from existing studies by presenting explanatory visualization results using SHAP, one of the XAI models.

• Journal of Korean Physical Therapy Science
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• v.3 no.2
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• pp.989-995
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• 1996

This study was conducted to investigate variation of cardiopulmonary function by use of building stairs, a questionnair survey and measurement was carried out for 50 students of department of physical therapy Andong Junior College from 20th September to 3rd October, 1995. The result were as follows: The average systolic blood pressure(SBP) of stability for 50 college students who were measured was 121.3 mmHg, the average diastolic blood pressure(DBP) of stability was 78.5 mmHg, the average pulse frequency of stability was 71.8(frequency/min), the average breathing frequency of stability was 20.4(frequency/min), and the body temperature of stability was $36.8^{\circ}C$. SBP among the second, third, and fourth floors was 129.0 mmHg, 127.0 mmHg, and, 132.0 mmHg (p=0.1919), DBP was 80.1 mmHg, 76.5 mmHg, and, 82.0 mmHg (p=0.4229), the pulse frequency was 74.0, 73.1, and 74.0(frequency/min). The breathing frequency among the second, third, and fourth floors was statistically gradually increased according to 21.4, 23.1 and 24.6(frequency/min)(p=0.0071). The body temperature among the second, third, and fourth floors was statistically less and less decreased according to $36.8^{\circ}C,\;36.6^{\circ}C$ and $36.5^{\circ}C$(p=0.0040). It was revealed by this study, the breathing frequency among the second, third, and fourth floors was statistically significant increased, the body temperature was statistically significant decreased.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.12 s.138
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• pp.1545-1553
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• 2004

This study assumes a bidimensional model of acculturation theory in order to understand the acculturation patterns of Korean-Americans and their fashion and shopping behavior. Bidimensional models of acculturation suggest that acculturating individuals may possess the components of both the heritage culture and the new, host culture. A combination of email and paper and pencil surveys was conducted with a convenience sample of Korean-Americans who are living in Seattle and vicinity area (n=108). The questionnaire included questions related to the respondents' and their parents' demographic information, the respondents perceived relationship with their parents, self-reported ethnic identification, ethnicity-related behaviors/attitudes, clothing involvement, shopping motivations, and fashion reference groups. The results support the bidimensional models of acculturation process as opposed to the linear model. Three different groups among Korean-Americans based on their ethnic identification pattern were found: a group with dominant Korean identity(Segregation group), a group with dominant American identity(Assimilation group), and a group with dual identity(Integration group). According to the results of MANOVA and subsequent Duncan and Scheffe tests, the Integration group showed distinct characteristics from Segregation group or Assimilation group, in terms of their ethnicity-related behaviors/attitudes, clothing involvement, shopping motivations, and fashion reference group influence.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.1
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• pp.8-15
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• 2016

Purpose: The purpose of this research is to determine whether pontic metal substructures, which are currently used in clinical surgeries, are designed appropriately and identify the problems that can occur due to their shape, size, and position. Then it aimed to emphasize the importance of making and designing pontic metal substructures based on basic principles. Materials and Methods: This research measured pontic basal surface (P1) used sample metal substructures in this study, gingiva margin (P2), and the porcelain thickness of maximum infrabulge of labial surface around 1/3 of cervix dentis (P3). One-way ANOVA analysis was carried out to test the differences among groups, Tukey Honestly Significant Difference Test was conducted for statistical analysis among groups. Results: For porcelain thickness and SD value, the P1 part was $1.2-1.8({\pm}0.17)mm$ for experimental group 1, $1.2-1.7({\pm}0.17)mm$ for experimental group 2, and $0.4-2.8({\pm}0.92)mm$ for experimental group 3. Next, the P2 part was $1.4-1.6({\pm}0.07)mm$ for experimental group 1, $1.3-1.8({\pm}0.07)mm$ for experimental group 2, and $0.5-2.7({\pm}0.67)mm$ for experimental group 3. The P3 part was $1.4-1.7({\pm}0.10)mm$ for experimental group 1, $1.5-2({\pm}0.10)mm$ for experimental group 2, and $0.9-3.1mm({\pm}0.90)$ for experimental group 3. There was no significance when One-way ANOVA analysis/Tukey Honestly Significant Difference Test was conducted for statistical analysis among groups (P > 0.05). Conclusion: The suggested metal substructures can be used clinically as they meet the requirements that pontic must have.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.138-144
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• 2013

Large and small marine accidents which are related to vessel's navigation are happening continuously and these maritime accidents have caused loss of lives and properties, and serious maritime environmental pollution damage. It is also true that maritime pollution damage is increasing due to these accidents, probability of growth of seaborne volume and complicated maritime traffic environment. Korea, recently, is developing an evaluation index which can assess sea risk through the evaluation of maritime traffic environment and provide danger and general information with relation to maritime traffic environment on target sea area to evaluate maritime traffic safety. In this paper, we intend to confirm the validity of maritime traffic safety on the basis of vessel navigator's risk consciousness and various sailing conditions by using the ship handling simulator. To confirm the validity of sailing vessel's maritime traffic safety, we use analysis of variance. By using analysis of variance, we analyze vessel navigator's characteristics, distance, speed and encounter type between vessels. Through multiple comparison of each factor's risk difference, we can confirm the change of numerical value of risk difference in statistical aspect.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.63-69
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• 2013

This paper related with the performance of SE-MMA (Signed-Error MMA) that is the reduction of computational operation number in algorithm than MMA blind eualization algorithm which are possible to elimination of intersymbol interferance in the band limited and time dispersive nonlinear communication channel. In MMA algorithm which are possible to reduction of amplitude and phase rotation by intersymbol interference that is occurred in channel without using the training sequence, it uses the error signal that is the difference of the equalizer output and constant modulus, the statisticlly characteristic of transmitted signal. But in SE-MMA, it uses the polarity of the error signal, then it is possible to reduce the updating the tap coefficient and to simplify the H/W implementation. The computer simulation were performed in order to compare the performance of SE-MMA and conventional MMA algorithm. For this, the recovered signal constellation that is the output of the equalizer, the convergence performance by MSE, MD (maximum distortion) and residual isi characteristic learning curve, SER were used. As a result of simulation, the SE-MMA has more fast convergence speed than the MMA. But in the other index after reaching the seady state, it gives more worst performance values in the used index.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.562-574
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• 2012

Simulation validation techniques which have been employed in most studies are statistical analysis, which validate a model with mean or variance of throughput and resource utilization as an evaluation object. However, these methods have not been able to ensure the reliability of individual elements of the model well. To overcome the problem, the weighted F-measure method was proposed, but this technique also had some limitations. First, it is difficult to apply the technique to complex system environment with numerous values of interarrival time because it assigns a class to an individual value of interarrival time. In addition, due to unbounded weights, the value of weighted F-measure has no lower bound, so it is difficult to determine its threshold. Therefore, this paper propose weighted F-measure technique with cluster analysis to solve these problems. The classes for the technique are defined by each cluster, which reduces considerable number of classes and enables to apply the technique to various systems. Moreover, we improved the validation technique in the way of assigning minimum bounded weights without any lack of objectivity.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.495-499
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• 2014

To search for myrmecochorous plant species, related ant species and diaspore selecting behaviour, collecting fruits and diaspores of four Corydalis species, cafeteria experiments, and the related ant species were studied from May 2013 to July 2014. Four Corydalis species recording in Korea were proved myrmecochorous (seed attached elaiosome) plants newly. Elaiosome shape of these species is spatulate-shaped, but their size is varied considerably in length and width. Significant differences is proved between four plant species in weight of diaspores, seeds and elaiosomes, and elaiosome ratios. Mean values of diaspores weight showed 4.08 mg, 2.56 mg, 2.49 mg and 2.06 mg in Corydalis grandicalyx, C. remota, C. turtschaninovii for. pectinata and C. turtschaninovii var. linearis, respectively. Mean values of seed weights showed 3.68 mg, 2.03 mg, 1.90 mg and 1.67 mg in Corydalis grandicalyx, C. remota, C. turtschaninovii for. pectinata and C. turtschaninovii var. linearis, respectively. Elaiosome ratio of C. turtschaninovii var. linearis was the highest, followed by C. remota, C. turtschaninovii for. pectinata and C. grandicalyx. Ant's preference for the diaspores is ordered as same as elaiosome ratio's order. Major ant species transporting the diaspores of Corydalis species are Formica japonica, Lasius alienus, Lasius japonicus and Tetramorium tsushimae. Formica japonica transports the diaspores most frequently. Ant's preference for the diaspores among plant species or individuals might be influenced on the survival rates of concerned species. Further studies on the myrmecochorous plant and related ant species, cafeteria experiments should be needed.