• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.4
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• pp.214-219
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• 2019

Purpose: The aim of this study was to evaluate the correlation between inter-condylar width and inter-maxillary first molar width to present the criteria for prosthetic reconstruction of dental arch width in maxillary and mandibular fully edentulous patients. Materials and Methods: 120 Koreans (60 males and 60 females) who underwent the cone beam computerized tomography (Cone-beam CT) were selected. The Cone-beam CT images were analysed using Invivo 5.1. After reorientation of axis, inter-maxillary first molar width was measured by clicking both mesio-buccal cusp tip of maxillary first molar. And inter-condylar width was measured by clicking both middle points of condyles. The collected data were analysed with SPSS Version 20.0 and statistical significance of the correlation between inter-condylar width and inter-maxillary first molar width was verified by Pearson's correlation analysis. Results: The mean inter-condylar width of Korean was 105.9 mm, and that of male (108.3 mm) was statistically significantly wider than the female (103.4 mm). The inter-maxillary first molar width of Korean was 57.1 mm, and that of male (57.9 mm) was statistically significantly wider than the female (56.2 mm). Pearson's correlation analysis between inter-condylar width and inter-maxillary first molar width showed a Pearson correlation coefficient of 0.614 and statistically significantly positive correlation. Conclusion: Intercondylar width and inter-maxillary first molar width showed positive correlation and the average ratio of inter-condylar with and inter-maxillary first molar width was 1:0.54. Based on the results of this limited study, inter-condylar width can be used as a guide for setting up dental arch width in fully edentulous patient.

• 대한공업교육학회지
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• v.41 no.1
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• pp.128-146
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• 2016

The purpose of this study was to provide a basic research data for increasing the quality of 'creative engineering design' lesson and the teaching learning capability of high school teachers by analyzing the teaching learning management status and improvement plan of 'technology home economics subject' lesson for high school teachers. In order to investigate the teaching learning management status, the survey questionnaires from 63 teachers were collected from high school teachers who teach technology home economics subject currently and analyzed by statistical program SPSS 20. The main results of this study were as follows: First, for the contents of 'creative engineering design' lesson, the highest mean of response was 'creative thinking method'(M=4.22). In the learning activities, the teachers perceived the importance of the 'idea concept' highly. Second, in the management of 'creative engineering design' lesson, the teachers perceived the importance of the secure of tool, material budget, and practice space for the lesson highly. In the teaching capabilities, the teacher perceived the importance of the preparing teaching learning strategy most($$M{\frac{._-}{.}}4.14$$). Third, the teachers preferred to product for making uncomfortable things better in life and the other production outside from the content of textbook. Fourth, in the ratio of practice:theory lesson, they perceived the ratio of 3:7(36.5%), 4:6(25.4%), and 2:8(23.8%) are appropriate. In the assessment, the combination of production, portfolio, and presentation was preferred most. Fifth, there were statistically significant difference in teachers' interest and satisfaction and contents about 'creative engineering design' lesson between groups divided by the existence of practice space, certification held(technology teacher, non technology teacher), etc. Therefore, in order to improve the interest and satisfaction about the 'creative engineering design' lesson, the secure of space for technology practice and material budget were required. In addition, training and seminars program for improving the teaching capability for 'creative engineering design' lesson were required.

• 대한공업교육학회지
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• v.44 no.2
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• pp.142-163
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• 2019

The purpose of this study is to analyze the effect of problem solving ability and satisfaction of university students who are pre-technology teachers in woodworking products(birdhouse) making program using design thinking. Survey responses are analyzed by statistical programs(SPSS ver.20) such as satisfaction, confidence in problem solving, difficulties and causes of difficulties according to gender and grade of 33 students who conducted experience programs in extra-curricular programs to improve creativity and problem solving ability. The main conclusions of this study are as follows: First, the average of total satisfaction about experience programs is 4.39, which is somewhat high. The highest average response is 'feelings of accomplishment' and 'advice in the surroundings'(M = 4.46). There is no significant difference between male and female, and grade. The students interest in group-based different birdhouse woodworking together with the help of the surrounding people by the process of design thinking rather than practice to follow. Therefore, I'd like to recommend to other students due to this program shows a high self-confidence, sense of accomplishment, and satisfaction. Second, the total average response of students 'self-confidence for problem solving at the group based making experience program using design thinking is 3.80. In result of group activities, the students have self-confidence of 'problem-solving ability and deal with difficult situations'. Later, in making programs, complementing difficulties of making can enhance the satisfaction of the students. Third, in the survey questionnaire related with problem solving ability confidence, between 'I have the ability to solve many problems' and 'I always have the ability to cope with new and difficult business situations' show the highest correlation. Therefore, in order to improve self-confidence of problem solving ability, it is necessary to prepare teaching learning programs that can strengthen problem solving ability. Fourth, in the new design and making process not a given product design, the most difficult step is 'the process of rework and modifying idea product'. The main reason that students have difficulty in the production process is 'lack of knowledge and ability to produce'. To make various woodworking products using design thinking process, it can be helpful to make works if you have enough training on woodworking and design thinking before product making. The students' satisfaction about team-based learning using design thinking that helps improving creativity and problem solving ability is high. Therefore, the result of the research in other making activity program that design thinking is applied and analyzed can improve students' problem solving ability.

• Journal of the Korean Society of Safety
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• v.10 no.3
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• pp.81-95
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• 1995

Now, safety assurance in construction sites should be accomplished by its own organization rather than control of the code or government. It is believed that the safety assurance can be considerably improved by a lecture or an education using the existing theories or literatures up to now, but it is thought that fundamental safety assurance we not able to be accomplished without developing safety devices '||'&'||' equipment or taking fundamental measures, based on the result analyzed from workers behaviors. There are various behaviors of the workers showed in construction site, but only tests for hammerusing works such as form, re-bar, stone workers directly related to the grip strength are mainly performed, investigated and measured here for the study. The above works are similar to power grip, 7th picture on seven items which are categorized for hand grip types(Ammermin 1956 ; Jones ; Kobrick 1958). Measurements of grip strength are commonly taken in anthropometric surveys. They are easy to administer but unfortunately it is rather dubious whether they yield any data that are of interest to the engineer. Very fewer controls of tools are grasped and squeesed studies showed very little overall correlation between grip strength and other measures of bodily strength (Laubach, Kromer, and Thordsen 1972), but hammer-using work which is practically progressed in construction site are mainly influenced with grip strength. According to the investigation on work measurement, it is shown that 77% of form worker are using hammer to be related to grip strength. In this study, it is particularly noticed that wearing safety gloves in construction site is required for workers safety but 20% difference between grip strength with safety gloves and without ones are commonly neglected in the site(Fig. 1). Nevertheless, safety operation with consideration of the above 20% difference is not considered in the construction site. Factors of age, kinds of work, working time, with or without safety gloves are in vestigated '||'&'||' collected at the sites for this study. Test, not at each working hour but at 14 : 00 when the almost all of the workers think the most tired, resulting from the questionaires, also when it is shown on the research report has been performed and compared for main kinds of works : form '||'&'||' re-bar work. Tests were performed with both left SE rightand of the workers simultaneously in construction site using Rand Dynamometer(Model 78010, Lafayette Instrument Co., Indiana, U.S.A) by reading grip strength on the gauge while they are pulling, and then by interviewing on their ages, works, experiences and etc., directly. The above tests have been performed for the dates of 15th march-26th May '95 with consideration of site condition. And even if various factors of ambient temperature on the testing date, working condition, individual worker's habit and worker's condition of the previous ate are concerned with the study. Those are considered as constants in this study. Samples are formwork 53, rebar 62, electrician 5, plumber 4, welding 1 from D construction Co., Ltd, ; formwork 12, re-bar 5, electrician 2, from S construction Co., Ltd, , formwork 78, re-bar 18, plumber 31, electrician 13, labor 48, plumber 31, plasterer 15, concrete placer 6, water proof worker 3, maisony 5 from B construction Co., Ltd. As In the previously mentioned, main aspect to be investigated in this study will be from '||'&'||' re-bar work because grip strength will be directly applied to these two kinds of works ; form '||'&'||' re-bar work, eventhough there are total 405 samples taken. It is thought that a frequency of accident occurrence will be mainly two work postures "looking up '||'&'||' looking down" to be mainly sorted, but this factor is not clarified in this study because It will be needed a lot of work more. Tests has been done at possible large scale of horizontally work-extended sites within one hour in order to prevent or decrease errors '||'&'||' discrepancies from time lag of the test. Additionally, the statistical package computer program SPSS PC＋has been used for the study.

• Journal of Intelligence and Information Systems
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• v.19 no.3
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• pp.73-91
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• 2013

Advertising market has been facing new challenges due to dramatic change in advertising channels and the advent of innovative media such as mobile devices. Recent research related to mobile devices is mainly focused on the fact that mobile devices could identify users'physical location in real-time, and this sheds light on how location-based technology is utilized to achieve competitive advantage in advertising market. With the introduction of smartphone, the functionality of smartphone has become much more diverse and context awareness is one of the areas that require further study. This work analyses the influence of context awareness value resulted from the transformation of advertising channel in mobile communication market, and our research result reflects recent trend in advertising market environment which is not considered in previous studies. Many constructs has intensively been studied in the context of advertising channel in traditional marketing environment, and entertainment, irritation and information are considered to be the most widely accepted variables that has positive relationship with advertising value. Also, in smartphone advertisement, four main dimensions of context awareness value are recognized: identification, activity, timing and location. In this study, we assume that these four constructs has positive relationship with context awareness value. Finally, we propose that advertising value and context awareness value positively influence smartphone advertising attitude. Partial Least Squares (PLS) structural model is used in our theoretical research model to test proposed hypotheses. A well designed survey is conducted for college students in Korea, and reliability, convergent validity and discriminant validity of constructs and measurement indicators are carefully evaluated and the results show that reliability and validity are confirmed according to predefined statistical criteria. Goodness-of-fit of our research model is also supported. In summary, the results collectively suggest good measurement properties for the proposed research model. The research outcomes are as follows. First, information has positive impact on advertising value while entertainment and irritation have no significant impact. Information, entertainment and irritation together account for 38.8% of advertising value. Second, along with the change in advertising market due to the advent of smartphone, activity, timing and location have positive impact on context awareness value while identification has no significant impact. In addition, identification, activity, location and time together account for 46.3% of context awareness value. Third, advertising value and context awareness value both positively influence smartphone advertising attitude, and these two constructs explain 31.7% of the variability of smartphone advertising attitude. The theoretical implication of our research is as follows. First, the influence of entertainment and irritation is reduced which are known to be crucial factors according to previous studies related to advertising value, while the influence of information is increased. It indicates that smartphone users are not likely interested in entertaining effect of smartphone advertisement, and are insensitive to the inconvenience due to smartphone advertisement. Second, in today' ubiquitous computing environment, it is effective to provide differentiated advertising service by utilizing smartphone users'context awareness values such as identification, activity, timing and location in order to achieve competitive business advantage in advertising market. For practical implications, enterprises should provide valuable and useful information that might attract smartphone users by adopting differentiation strategy as smartphone users are sensitive to the information provided via smartphone. Also enterprises not only provide useful information but also recognize and utilize smarphone users' unique characteristics and behaviors by increasing context awareness values. In summary, our result implies that smartphone advertisement should be optimized by considering the needed information of smartphone users in order to maximize advertisement effect.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.3
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• pp.42-50
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• 2012

City squares are public open spaces which are closely related to the peoples daily lives. Most squares are located in the center of the city, and they are usually used for community gatherings and they are suitable for open markets, music concerts, political rallies, and other events. City squares also play an important role as a grand public place operating in multi functions that require involvement of more people. The purpose of this study is to examine satisfaction on the spatial components, characteristics, and the user satisfaction in City Squares. The slady also analyzed the relationship between the satisfaction about spatial components, characteristics and it also shows that the user satisfaction is followed. This study sites are made in 3 grand public places in the center of Seoul including the Seoul plaza, Cheonggye Plaza, and Gwanghwarnun Square. Data were analyzed using several statistical methods such as descriptive statistics, factor analysis, ANOVA, correlation and regression. Results of the study are as follows: First, factor analysis carried out to extract the various factors of satisfaction on the sites; spatial components, usability, amenity/security, and spatial characteristics. User satisfaction concerning usability factor was higher than the satisfaction of the other factors. This result represented that the slady sites play an important role to the public open spaces in the city. Second, users showed high user satisfaction to study sites, and user satisfaction rate toward the Gwanghwarnun Square is the highest because of its facility planuing. Finally, user satisfactim was strongly correlated on the usability factor of spatial planning. Also, the significant correlations between the user satisfaction and the other factors such as spatial components, security, and spatial characteristics of spatial planning are presented. Results of this study can help guide the planning and management of the city square as a public open space based on the understanding of user perception and satisfaction.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.5
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• pp.53-63
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• 2010

The purposes of this study are to classify the characteristics of parks by park use patterns and the understanding of design concepts and to analyze the difference of cognition of design concept between designers and park users. The literature studies and surveys were performed to analyze park use patterns and understanding of design concepts for Seoul Forest Park, Yeouido Park and Seonyudo Park. Several statistical methods have been used such as descriptive analysis and importance-performance analysis. The results of this research are as follows. As the results of an analysis of park use patterns, Seonyudo Park may he qualified as an urban landmark park, while Yeouido Park can he classified as a neighborhood park. Seoul Forest Park bas characteristics of both. Second, the higher frequency of visits generally leads higher preference. Third, the overall cognition of the design concepts of parks shows 3.51 on average, which is comparatively high. The functional concepts are better transmitted to the users compared to abstract concepts. The cognition of the design concepts of each park are evaluated in the higher order of Seonyudo Park, Seoul Forest Park and Yeouido Park. Fourth, the cognition levels of detailed design concepts for each place are lower than the overall design concepts. On the other hand, levels of satisfaction are increased after the design concepts are noticed. It would he necessary make the effort to give information about the design concept of each space. The results of this study are limited in that it covers only three parks in Seoul, and did not consider seasonal variables. Nevertheless, this study may he significant in that it dealt with the cognition of design concepts for urban parks, focusing on the difference between designers and visitors.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.4
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• pp.19-28
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• 2020

The Urban Heat Island (UHI) Effect has intensified due to urbanization and heat management at the urban level is treated as an important issue. Green space improvement projects and environmental policies are being implemented as a way to alleviate Urban Heat Islands. Several studies have been conducted to analyze the correlation between urban green areas and heat with linear regression models. However, linear regression models have limitations explaining the correlation between heat and the multitude of variables as heat is a result of a combination of non-linear factors. This study evaluated the Heat Island alleviating effects in Seoul during the summer by using a deep neural network model methodology, which has strengths in areas where it is difficult to analyze data with existing statistical analysis methods due to variable factors and a large amount of data. Wide-area data was acquired using Landsat 8. Seoul was divided into a grid (30m × 30m) and the heat island reduction variables were enter in each grid space to create a data structure that is needed for the construction of a deep neural network using ArcGIS 10.7 and Python3.7 with Keras. This deep neural network was used to analyze the correlation between land surface temperature and the variables. We confirmed that the deep neural network model has high explanatory accuracy. It was found that the cooling effect by NDVI was the greatest, and cooling effects due to the park size and green space proximity were also shown. Previous studies showed that the cooling effects related to park size was 2℃-3℃, and the proximity effect was found to lower the temperature 0.3℃-2.3℃. There is a possibility of overestimation of the results of previous studies. The results of this study can provide objective information for the justification and more effective formation of new urban green areas to alleviate the Urban Heat Island phenomenon in the future.

• Restorative Dentistry and Endodontics
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• v.32 no.3
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• pp.208-221
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• 2007

The fracture toughness test is believed as a clinically relevant method for assessing the fracture resistance of the dentinal restoratives. The objectives of this study were to measure the fracture toughness $(K_{1C})$ and microtensile bond strength of dentin-resin composite interface and compare their relationship for their use in evaluation of the integrity of the dentin-resin bond. A minimum of six short-rod specimens for fracture toughness test and fifteen specimens for microtensile bond strength test was fabricated for each group of materials used. After all specimens storing for 24 hours in distilled water at $37^{\circ}C$, they were tensile-loaded with an EZ tester universal testing machin. Statistical analysis was performed using ANOVA and Tukey's test at the 95% confidence level, Pearson's coefficient was used to verify the correlation between the mean of fracture toughness and microtensile bond strength. FE-SEM was employed on fractured surface to describe the crack propagation. Fracture toughness value of Clearfil SE Bond (SE) was the highest, followed by Adper Single Bond 2 (SB), OptiBond Solo (OB), ONE-STEP PLUS (0S), ScotchBond Multi-purpose (SM) and there was significant difference between SE and other 4 groups (p < 0.05). There were, however, no significant difference among SB, OB, OS, SM (p > 0.05). Microtensile bond strength of SE was the highest, followed by SB, OB, SM, OS and OS only showed significant lower value (p < 0.05). There was no correlation between fracture toughness and microtensile bond strength values. FE-SEM examination revealed that dentin bonding agent showed different film thickness and different failure pattern according to the film thickness. From the limited results of this study, it was noted that there was statistically no correlation between K1C and ${\mu}TBS$. We can conclude that for obtaining the reliability of bond strength test of dentin bonding agent, we must pay more attention to the test procedure and its profound scrutiny.

• The KIPS Transactions:PartB
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• v.10B no.3
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• pp.281-286
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• 2003

A large number of features are collected for problem solving in real life, but to utilize ail the features collected would be difficult. It is not so easy to collect of correct data about all features. In case it takes advantage of all collected data to learn, complicated learning model is created and good performance result can't get. Also exist interrelationships or hierarchical relations among the features. We can reduce feature's number analyzing relation among the features using heuristic knowledge or statistical method. Heuristic technique refers to learning through repetitive trial and errors and experience. Experts can approach to relevant problem domain through opinion collection process by experience. These properties can be utilized to reduce the number of feature used in learning. Experts generate a new feature (highly abstract) using raw data. This paper describes machine learning model that reduce the number of features used in learning using heuristic function and use abstracted feature by neural network's input value. We have applied this model to the win/lose prediction in pro-baseball games. The result shows the model mixing two techniques not only reduces the complexity of the neural network model but also significantly improves the classification accuracy than when neural network and heuristic model are used separately.