• The Journal of Korean Academy of Prosthodontics
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• v.36 no.1
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• pp.120-132
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• 1998

This stusy was to investigate the marginal fitness of porcelain-fused-to- metal crown after succesive firing cycle. Main variables were the degree of marginal curvature of labiocervical margin and the type of alloy. The exaggerated marginal curvature(EMC) was created by additional reduction at the faciocervical wall of the normallized marginal curvature (NMC)-typed ivorine tooth by using milling machine. The difference in the shape was the mid facial margin was placed 2mm apical to cemento- enamel junction in labial surface. Three types of alloy were high noble, noble, and base metal alloy. Test specimens were divided into 8 groups and each group had 8 specimens. Sixty four ceramometal crowns were made totally. Measurement stages were following degassing, opaquing. body porcelain firing, and glazing, and measuring sites were 4. (midmesial, midfacial, middistal, and midlingual). Digital, travelling measuring microscope (0.5 um precision, Olympus. Japan) was used under ${\times}250$ magnification. Within the limitation of this investigation, it was concluded as belows: 1. The pattern of marginal distortion was varied. Degassing stage was not a specific, causative stage that induce most of total marginal distortion during whole procedure fabricating a ceramometal crown. Body firing stage induced discrepancy relatively more than other firing stages. 2. The specimens that were Ni-based alloy and had EMC were distorted persistently following successive fabricating procedures. But marginal openings were decreased after glazing. 3. The release of metal grinding-induced stress was presumed as a cause that induce marginal distortion. 4. The amount of discrepancies of the labial and lingual margins were greater than that of the mesial and distal margin in the specimen that had EMC. 5. Silver-plated die was not enough to resist abrasion during repeated seating of metal copings on the die-holding device.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.7
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• pp.1194-1203
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• 2000

A magnetic field exposure system that generates 60 Hz magnetic fields from 1 mG to 5 G was designed and constructed for small-sized animal study. In order to investigate as many animals as possible at one series of test, uniform magnetic fields are required at wide living area of the animals. In this article, a cubic shaped field exposure system with three animal living floors was designed, which offers about 50 seating capacity. For calculation of magnetic fields inside the cage, a three-dimensional calculation program was developed. Using this, optimum electric current ratio of inner coil to outer coil and position of each coil were determined. Meanwhile, inductance of the exposure system was calculated for the design of power supply. The field measurement results of the manufactured exposure system showed that the difference between maximum and minimum magnetic field at the testing floors was less than 3%, which strongly demonstrated the field exposure system was good for small sized animal study.

• Journal of the Korea Furniture Society
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• v.19 no.1
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• pp.44-54
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• 2008

The blur phenomenon, in which the boundaries of fields or roles become vague, has become an important concept of design in the 21st century. In furniture design, the physical boundary between furniture and space and that between space and furniture has been broken down and their meaning tends to be redundant. This concept was begun by a variety of furniture designers who led the trends about 30 years ago. A progressive exhibition titled ${\ulcorner}$Living Tomorrow${\lrcorner}$, which was included in the Koln International Mobelmess from 1968 to 1970, showed that the blur phenomenon in furniture design has never actually been novel. These exhibitions and the works exhibited in the events are still recognized as progressive examples that proposed an avant-garde concept of life. They are in line with the current furniture design based on spatial concepts, which has been created by the blur phenomenon. The purposes of this study are to determine the cases of furniture design that enable the so-called spatial functions beyond the simple functions of seating, use, and display, from those of furniture design and to research their characteristics. In this study, furniture based on spatial concepts means furniture that creates 3D spaces consisting of the floor, walls, and ceiling by the blur phenomenon that occurs from the spaces among these pieces of furniture. The organization of this study is as follows; In Chapter 2, a background on the generation of furniture design based on spatial concepts is described based on the research literature of this socio-cultural phenomena. In Chapter 3, the cases of relevant furniture design redescribed. In Chapter 4, the collected cases are analyzed and their characteristics described. In Chapter 5, Chapter 1 to Chapter 4 are summarized and conclusions are given. In addition, future research is proposed.

• Journal of Korean Institute of Industrial Engineers
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• v.28 no.2
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• pp.216-222
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• 2002

The ergonomic human model can be considered as a tool for the evaluation of ergonomic factors in vehicle design process. The proper anthropometric data on driver's postures are needed in order to apply a human model to vehicle design. Although studies on driver's posture have been carried out for the last few decades, there are still some problems for the posture data to be applied directly to the human model due to the lack of fitness because such studies were not carried out under the conditions for the human model application. In the traditional researches, the joint angles were evaluated by the categorized data, which are not appropriate for the human model application because it is so extensive that it can not explain the posture evaluation data in detail. And the human models require whole-body posture evaluation data rather than joint evaluation data. In this study a postural evaluation function was developed not by category data but by the concept of the loss function in quality engineering. The loss was defined as the discomfort in driver's posture and measured by the magnitude estimation technique in the experiment using a seating buck. Four loss functions for the each joint - knee, hip, shoulder, and elbow were developed and a whole-body postural evaluation function was constructed by the regression analysis using these loss functions as independent factors. The developed postural evaluation function shows a good prediction power for the driver's posture discomfort in validation test. It is expected that the driver's postural evaluation function based on the loss function can be used in the human model application to the vehicle design process.

• The Journal of the Korea Contents Association
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• v.14 no.1
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• pp.466-477
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• 2014

This research aims to analyze the importance-performance among airline selection attributes using foreign tourists. For this purpose, data were collected from Japanese and Chinese tourists to Korea. Of the various airline selection attributes, four factors were deduced that includes: transport service, accompany service, cabin service and basic service using exploratory factor analysis. This study estimated how important airline selection attributes are and how much are they performed. Also, this study analyzed the ranking among each selection attributes using T-test. The importance-performance analysis showed 'Concentrate Here' in quadrant I, 'Keep up the Good Work' in quadrant II, 'Low Priority' in quadrant III and 'Possible Overkill' in quadrant IV. Quadrant I specifically showed low performance in terms of the following specific attributes: communicative convenience, flight attendant's friendliness, seating preference. As these attributes are deemed significant, airline managers should focus along these areas.

• IE interfaces
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• v.23 no.2
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• pp.100-107
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• 2010

For proper ergonomic evaluation using a digital human model simulation (DHMS) system such as $RAMSIS^{(R)}$, the postures of humanoids for designated tasks need to be predicted accurately. The present study (1) evaluated the accuracy of driving postures of humanoids predicted by RAMSIS, (2) proposed a method to improve its accuracy, and (3) examined the effectiveness of the proposed method. The driving postures of 12 participants in a seating buck were measured by a motion capture system and compared with their corresponding postures predicted by RAMSIS. Significant discrepancies ($8.7^{\circ}$ to $74.9^{\circ}$) between predicted and measured postures were observed for different body parts and driving tasks. Two methods (constraints addition and user-defined posture) were proposed and their effects on posture estimation accuracy were examined. Of the two proposed methods, the user-defined posture method was found preferred, reducing posture estimation errors by 11.5% to 84.9%. Both the posture prediction accuracy assessment protocol and user-defined posture method would be of use for practitioners to improve the accuracy of predicted postures of humanoids in virtual environments.

• Korean Institute of Interior Design Journal
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• v.25 no.5
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• pp.140-147
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• 2016

This research aims to establish the size standard of university library's user space, and present the standard and method to calculate total area required in the planning of new building construction and remodeling. Nine university libraries newly constructed or remodeled since 2000 were selected among the libraries of large scale universities with more than 10,000 enrolled students as the target libraries in this research. The target libraries were classified into A group (five cases partially remodeled) and B group (four cases newly constructed or fully remodeled) on the basis of the change of times. A university library can be divided into three spaces (user space, administration space and public space). This research classified the reading room in the user space into bookshelf zone, reading zone, information/office zone and hall/other zone, and analyzed area ratio according to each zone. B group's bookshelf zone decreased 12% more than A group, and B group's reading zone increased 10% more than A group. However, there was no big change in the area ratio of information/office zone and hall/other zone. This can be interpreted that university library changes from book and archive preservation-oriented space to user-oriented space. This research presented a proper reading room area calculation method, based on the capacity of books, by reflecting such a change. Each zone's standard was set up through classification of domestic and international standards, based on which, the calculation method of university library's total floor area required was presented. The reason why there was difference in university library's total floor area required according to domestic standard and international standard was that the number of enrolled students per seat in the reading room was different. The area calculation methods presented in this research can be utilized as useful data upon planning university library construction or remodeling.

• Journal of Korean Library and Information Science Society
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• v.47 no.1
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• pp.243-277
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• 2016

This study aimed at analyzing the influence factors of the academic library on college's education and research performances. The researched subject was 144 colleges targeted for information disclosure by Center for Higher Education Information Disclosure. The conclusion of the present study is as follows. First, the educational performance in college showed the positive relation with 'library environment' variables except 'seating capacity per capita'. Second, the educational performance in college was positively related to the variable of 'library outcome' and particularly, it was directly influenced by circulation, visit, and interlibrary loan. Third, the research performance in college showed a positive correlation with 'library environment' variables except facility scale of library. Fourth, the research performance in college showed a positive relation with the variable of 'library outcome' and research performance excluding 'publication in domestic journals per capita' was positively influenced by 'document delivery services usage per capita' and 'commercial DB usage per capita' in common.

• The Journal of Advanced Prosthodontics
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• v.3 no.4
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• pp.196-203
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• 2011

PURPOSE. This study evaluated marginal fit of glass infiltrated alumina cores fabricated using two techniques and their marginal stability after firing cycles of veneering porcelain. MATERIALS AND METHODS. Fifteen standardized all-ceramic crowns were fabricated on a metal die using each technique: slip cast technique of VITA In-Ceram sprint Alumina (Group A as control) and plastic foil matrix technique of Turkom-Cera fused alumina core system (Group B). Copings were compared between groups and within groups at coping stage and after firing each layer of veneering porcelain. A device was used to standardize seating of copings on the metal die and positioning of the specimens under the microscope after each stage of fabrication. The specimens were not cemented and marginal gap was measured using an image analyzing software (Imagepro Express) on the photographs captured under an optical microscope. Two tailed unpaired 't test' was used to compare marginal gaps in two groups and one way ANOVA was used to analyze marginal distortion within each group at 95% confidence interval. RESULTS. The marginal gap was smaller at the coping stage in group B ($60+30{\mu}M$) than group A ($81+21{\mu}M$) with statistical significance. After firing of veneering porcelain the difference was insignificant. At the final stage, both groups exhibited lower mean marginal gaps than at the initial coping stage with the difference of $11.75{\mu}M$ for group A and $11.94{\mu}M$ for group B, but it was statistically insignificant due to high value of standard deviation. CONCLUSION. Within the limitations of this study, it was concluded that both techniques produced copings with comparable and acceptable marginal fit and marginal stability on firing veneering porcelain.

• Journal of Families and Better Life
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• v.27 no.5
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• pp.77-90
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• 2009

The purpose of this study was to investigate the residents' use and occupancy-behavior in the activity areas of the senior nursing facilities, and to provide basic information to establish the appropriate physical elements for planning the activity areas. For the study, the observations in five facilities were conducted for one day, from 10 a.m. to 4 p.m by four researchers. The results of the study are summarized as follows: First, most of the using behaviors in the activity areas were the doing nothing or sleeping. The meals and program services were provided in only one activity area of the floor and it showed that the unit care system was perfunctorily conducted at those facilities. In the representative activity area, its openness was the main physical element influencing the spatial using frequency, while the accessibility and the openness in the sub-activity area were most important. The seating arrangements having comers were helpful for residents' interactions. Second, while facility programs and meals were provided in the specific activity area, there was no residents' occupancy in other activity areas at the same time. There were interactions including residents' conversations and watching/observations in non-designated activity areas such as the nursing stations and near corridors. But the residents' interactions and self-regulations were blocked by absence of territoriality, monotonous spatial compositions and furniture arrangements, insecurity of residents' privacy, wide or narrow areas, and isolated spatial type. Based on the results at the above, basic guidelines for planning the activity areas of senior nursing facilities can be proposed as follows: First, the isolated type and the sight interception should be avoided in representative activity areas. It should be partitioned with couple of areas through the appropriate furniture arrangements, and be prepared semi-private spaces in non-designated areas such as nursing station for the interactions among the residents and the staff. Second, in activity areas for small group, the isolated type is not also good for the residents' accessibility. The residents' privacy should be confirmed through the various spatial compositions, and enough areas need to be sure for the diverse furniture arrangements.