• The Journal of Korean Academy of Prosthodontics
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• v.42 no.1
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• pp.83-93
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• 2004

Statement of problem : Since the concept of osseointegrated dental implant by $Br{\aa}nemark$ et al was first applied to mandibular full edentulous patients. Recently it is considerated the first treatment option on missing teeth. A common problem associated with dental implant restorations is loosening of screws that retain the prosthesis to the abutment and the abutment to the implant fixture. Purpose : This study is to examine the influence on screw loosening of implant-abutment designs. Material and methods : External hex, cone screw, beveled hex, cam cylinder, cylinder hex by means of evaluating the loosening torques, with respect to a range of tightening torques after repeated loading. Result : 1. Cone screw, beveled hex groups are the highest initial tightening rate and cylinder hex, external hex groups are the lowest initial tightening rate (p < 0.05). 2. Cone screw groups are the highest after repeated loading tightening rate and cylinder hex groups are lowest after repeated loading tightening rate(p < 0.05). 3. Cone screw groups have the highest initial stability and anal stability. 4. All groups are decreased tightening rate after repeated loading.

• ETRI Journal
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• v.33 no.6
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• pp.864-870
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• 2011

As an isotropic conductive adhesive, that is, a hybrid Cu paste composed of Cu powder, solder powder, and a fluxing resin system, has been quantitatively characterized. The mechanism of an electrical connection based on a novel concept of electrical conduction is experimentally characterized using an analysis of a differential scanning calorimeter and scanning electron microscope energy-dispersive X-ray spectroscopy. The oxide on the metal surface is sufficiently removed with an increase in temperature, and intermetallic compounds between the Cu and melted solder are simultaneously generated, leading to an electrical connection. The reliability of the hybrid Cu paste is experimentally identified and compared with existing Ag paste. As an example of a practical application, the hybrid Cu paste is used for LED packaging, and its electrical and thermal performances are compared with the commercialized Ag paste. In the present research, it is proved that, except the optical function, the electrical and thermal performances are similar to pre-existing Ag paste. The hybrid Cu paste could be used as an isotropic conductive adhesive due to its low production cost.

• Wind and Structures
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• v.32 no.5
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• pp.405-421
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• 2021

To gain insight into the wind-induced safety concerns associated with attached tower cranes during the construction of super-tall buildings, a 606 m level frame-core tube super-tall building is selected to investigate the wind-induced vibration response and fragility of an outer-attached tower crane at all stages of construction. The wind velocity time history samples are artificially generated and used to perform dynamic response analyses of the crane to observe the effects of wind velocity and wind direction under its working and non-working resting state. The adverse effects of the relative displacement response at different connection supports are also identified. The wind-resistant fragility curves of the crane are obtained by introducing the concept of incremental dynamic analysis. The results from the investigation indicate that a large relative displacement between the supports can substantially amplify the response of the crane at high levels. Such an effect becomes more serious when the lifting arm is perpendicular to the plane of the connection supports. The flexibility of super-tall buildings should be considered in the design of outer-attached tower cranes, especially for anchorage systems. Fragility analysis can be used to specify the maximum appropriate height of the tower crane for each performance level.

• Journal of the Korea Convergence Society
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• v.10 no.7
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• pp.33-37
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• 2019

Nowadays, the needs for linking smart devices are growing fast because of wide spread of smart devices such as smart TV, smart phones, smart pad and so on. This paper presents a game framework for linking smart TV and smart phones and proves its applicability by developing an example contents. The problem of connection between smart devices is basically a problem of connection between heterogeneous devices. The problem is that data transmission and reception between heterogeneous devices must be considered. Therefore, the core data is implemented by adopting the concept of cloud computing and storing it in a server, and in a smart TV, playing the game by using this data. The proposed framework could be applied to a lot of applications such as computer games.

• The Journal of Korean Society for School & Community Health Education
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• v.19 no.3
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• pp.95-108
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• 2018

Objectives: The purpose of this study was to investigate the actual conditions and operational problems of Health Promotion Model School' in high school. Methods: We conducted a content analysis of 2014 results report and staffs' responses of five high schools among 85 'Health Promotion Model Schools' led by Ministry of Education from 2012 to 2014. Results: The study examined the operational process of health promoting schools in five stages; system development, needs survey & current status survey, school health policy development, program development & execution, and evaluation. Every step was found to be inadequate. In addition, the study discovered three key factors in operating health promoting schools and examined the status of each factor; connection with the curriculum, connection with the community, and consensus among members. Three factors were also applied poorly. Compared to elementary school, high school showed a lack of all respects. Health promoting school staffs have faced difficulties in linking community resources, organizing and operating a working committee, conducting surveys and assessing health problems, preparing self-assessment or external evaluation, and developing strategies and programs. In order to solve the operational problems, active cooperation of all teachers is urgent. Conclusion: 'Health Promotion Model School' conducted in high school is not considered to have faithfully implemented WHO's concept of health promoting school. In the future, incentive policies for health promoting school teachers should be actively reviewed.

• Korean Institute of Interior Design Journal
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• v.21 no.1
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• pp.211-219
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• 2012

I.M. Pei, 2nd generation Chinese immigrant to America, has been one of the most recognized architects who designs museum architecture through out the world for completing significant projects such as the East Building of National Gallery of Art(1068-78) as well as Le Grand Louvre Renovation(1983-89) to name a few. His museum architecture, in particular, reveals his detailed consideration on viewer's artistic experience by providing well balanced architecture design to support exhibiting objects while showing his sensitivity on overall functionality of space. In recent projects such as Miho Museum in Japan, Suzhou Museum of China, and Museum of Islamic Art of Qatar, reveals his growing interests in considering "local context" in museum architecture. Therefore, the purpose of this study is focused on analyzing I.M. Pei's three museum projects having its concept focused on local context. Through out the paper, above mentioned museums were analyzed and compared to summarize his design characters and concept including site plan, spatial organization and architectural form. As a result, it is evident that I.M. Pei had put full effort to apply oriental context with modernism through out his museums. In particular, his site plan, spatial organization, and architectural form shows visible connection to comply with nature which is fundamental idea in oriental philosophy. While his basic design philosophy has been borrowed from the tradition, his ultimate design concept shows nature friendliness as well as theoretical system of thoughts and emotion and most of all, his design excellency in representing local context.

• Journal of the Korean School Mathematics Society
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• v.13 no.3
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• pp.483-498
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• 2010

The purpose of this paper is to investigate the dispositions of university students' understanding and reasoning about rational number concept. For this, we surveyed for the subject groups of prospective math teachers(33), engineering major students(35), American engineering and science major students(28). The questionnaire consists of four problems related to understanding of rational number concept and three problems related to rational number operation reasoning. We asked multi-answers for the front four problem and the order of favorite algorithms for the back three problems. As a result, we found that university students don't understand exactly the facets of rational number and prefer the mechanic approaches rather than conceptual one. Furthermore, they reasoned illogically in many situations related to fraction, ratio, proportion, rational number and don't recognize exactly the connection between them, and confuse about rational number concept.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.7
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• pp.1346-1367
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• 2011

As the size of camera modules is decreasing and as the computing performance of portable devices is improving, taking photos has become a part of daily life. However, existing photo management programs and products that manage such photos still require extensive user effort to facilitate the sharing and browsing of images. It is especially difficult for novice users to manage and share photos. In this paper, we develop a round-robin concept-driven user preference feedback mechanism for achieving direct photo sharing, instant display, and easy management using optimized user controls and user preference-driven classification. Compared with commercial photo management systems, our proposed solution provides new features: optimized user controls, direct sharing and instant display, and user preference feedback driven classification. These new features boost the round-robin concept-driven user preference feedback. This paper proposes a photo finder that automatically searches for photos in storage spaces or cameras. The proposed photo finder relies on user preference feedback to share photos by leveraging user preferences, and the round-robin connection transmits photos to the family's digital photo frame or web album by arbiter. The proposed method saves time and spares users the effort required for photo management. Moreover, this method does not merely direct photo sharing and simple photo management, but it also increases the satisfaction level of users viewing the photos.

• Journal of Fashion Business
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• v.14 no.5
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• pp.78-92
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• 2010

The culture phenomenon, which the desire of self expression is noticeable and the diversity of gender identity is widely accepted, simply makes a difference in the lifestyle of one human being rather than the dichotomous classification of male and female. Now, the delicate and aesthetic sensitivity classified as the feminine characteristics is no longer the exclusive property of female and this refers to substituting it as a social gender from the concept of biological sex. This phenomenon has influenced on the male culture and is creating various codes according to the cultural gender extended from the gender as a social role. Also, the transition into the western lifestyle has extended the aesthetic emotion to accommodate new codes from the diversification and globalization of lifestyle. The mansumer power, which does not care too much about the money for the emotionally attached items, has enabled various fashion styles. After analyzing the diversified clothing behavior conducted by these people in connection with the social phenomenon, First, this shows the phenomenon of emotional value pursuit that finds pleasure over the clothing as the item of augmented reality is added to the concept of play, in which the real space referred to as garment and virtual space of playing the rock, paper and scissors game meet together within the augmented reality. Second, the convergence concept has enabled the coordination of new style by obscuring the area of design concept and this refers to the changes in design from the development of new items and transformation into double-style details. Third, the divergence that intensively provides specific use/convenience and specialized value shows a change in the fashion market from the phenomenon that admits various gene rations of culture and specifically, takes differently about the recognition of middle-aged males. Fourth, the variety seeking tendency receives attention as the value of future design together with the phenomenon of discriminative value pursuit. In the male fashion, it is linked to the collaboration with the design area and this tells that the fashion with the narcissistic cross-dressing and motto of neutral gender without being sided to male/female is rising.

• School Mathematics
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• v.1 no.2
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• pp.637-660
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• 1999

Although ‘to understand mathematics’ is an important educational purpose, most student do not have a relational understanding of the basic concept of mathematics but have a instrumental understanding. This paper will investigate the possibility of using computers for enhancing relational understanding. In the ‘Qualitative case study’, three students who are in the first grade at E-High school took part in 7 activities during four weeks, and were later interviewed and engaged in informal discussion and were observed. This is the result of this study. 1. The three students were passive participants in mathematics problem solving situation at school. Therefore, student B just applied formulas which she had memorized, and student C would forgot the formulas occasionally. These common students needed to participate actively in doing mathematics. 2. The activities utilized two software healing with connection between graphs and function, giving the students the opportunity to plan, practice, and test by themselves. As a result, they understood the mathematical formulas and rules more deeply through their own trial and error, and then they gained thinking abilities necessary for doing mathematics. In addition, the activities boosted their confidence. 3. The understanding type of students was slightly different. Student A who received a high score, understood the most relationally, but student B who received a very high score, understood instrumentally and so couldn't app1y her knowledge to solving problems related to function concept. Student C who received a middle score lacked knowledge of mathematics but thought more creatively. The result is that students need an opportunity to think rotationally regardless of score. Therefore, this study concludes that using computer software will provide a positive effect for relational understanding in loaming function concept.