• The Journal of Advanced Prosthodontics
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• 제8권6호
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• pp.449-456
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• 2016

PURPOSE. This in vitro study evaluated the effects of four different cements on the color attributes of a zirconia ceramic. MATERIALS AND METHODS. 40 zirconia ceramic disk specimens (0.5 mm thickness, 10 mm diameter, 0.1 mm cement space) were fabricated by a computer-aided design and computer-aided manufacturing system. The specimens were divided into 4 groups of 10 specimens and cemented to composite substrates using four different cements including: Glass Ionomer, Panavia F2.0, Zinc Phosphate, and TempBond. The $L^*$, $a^*$, and $b^*$ color attributes of the specimens were measured before and after cementation by a spectrophotometer. Additionally, ${\Delta}E$ values were measured to determine color changes for the groups and then compared with the perceptional threshold of ${\Delta}E=3.3$. Repeated Measures ANOVA, Tukey Post Hoc, Bonferroni, One-way ANOVA, and One-sample t-test tests were used to analyze the data. All tests were carried out at the 0.05 level of significance. RESULTS. Statistically significant differences were detected in the ${\Delta}E$ values for Zinc Phosphate (P<.0001) and TempBond (P<.0001) groups. However, there were no statistically significant differences in this respect for Glass Ionomer (P=.99) and Panavia F2.0 (P=1) groups. The means and standard deviations of the ${\Delta}E$ values for Glass Ionomer, Panavia F2.0, Zinc Phosphate, and Tempbond groups were $2.11{\pm}0.66$, $0.94{\pm}0.39$, $5.77{\pm}0.83$, and $7.50{\pm}1.16$ Unit, respectively. CONCLUSION. Within the limitations of this study, it was concluded that Zinc Phosphate and Tempbond cements affected the color attributes of the tested zirconia ceramic beyond the perceptional threshold. However, Glass Ionomer and Panavia F2.0 cements created acceptable color changes.

• Journal of the Institute of Convergence Signal Processing
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• 제5권4호
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• pp.308-316
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• 2004

As we know that there are so many restrictions controlling the autonomous robot to turn and move in an indoor space. In this research, Ive adopted the concept ‘Omni-directional wheel’ as a driving equipment, which makes it possible for the robot to move in horizontal and diagonal directions. Most of all, we eliminated the slip error problem, which can occur when the system generates power by means of slip. In order to solve this problem, we developed a ‘slip error correction algorithm’. Following this program, whenever the robot moves in any directions, it defines its course by comparing pre-programmed direction and the current moving way, which can be decided by extracted image of floor line. Additionally, this robot also provides the limited security and service function. It detects the motion of vehicle, transmits pictures to multiple users and can be moved by simple order's. In this paper, we tried to propose a practical model which can be used in an office.

• Journal of Korean Society of Forest Science
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• 제90권5호
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• pp.585-592
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• 2001

Interest in the development of urban trails is growing in South Korea. River front trails have been developed in Seoul, Daegu and other major cities. Such trails, and the corridors in which they are developed, often provide a myriad of benefits to the community, including open space, exercise, and stress release. This trend mirrors development patterns found in the United States and European nations. This study examined differences in trail users perceptions of trail attributes, activity participation, willingness to pay for trail access, and perceptions of trail benefits between trail users in the United States and those in South Korea. Perceptions of trail users at three trail sites in the metropolitan area of Daegu were examined, and then were compared to results reported in several studies conducted in the U. S. While this research was exploratory, it did uncover many interesting differences in perceptions of trail attributes between trail users in the two countries. This information may provide insight into the development of greenway systems in South Korea.

• Culinary science and hospitality research
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• 제15권1호
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• pp.30-46
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• 2009

This study analyzes the factors to determine the location for a food service business. The results and suggestions are as follows. Research hypothesis showed that accessibility, visibility, the property of location and community may have differences by general matters and vital statistical matters. As a result, there were significant differences statistically. Here's the critical point of the research. This result wasn't analyzed by the managers who managed restaurant business because of the restriction of time, space, etc. but by customers and soon-to-be owners or marketers, so the research requires the survey on the factors of location hereafter. Because of the restrictions, the research subject was limited, so the measurement of the vital statistics is inaccurate. According to researcher's opinion, it's a little unjustifiable to generalize this research for all types of restaurant business and conditions. The next research needs to analyze the research results by conditions and much more various subjects.

• Journal of the Korean Institute of Educational Facilities
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• 제6권2호
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• pp.24-40
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• 1999

The purpose of this study is planning a representative model of a modernized school with rearrangement of existing two primary schools(Nammyun and Namjin) and a middle school(Seonam) in Nammyun distric. Nammyun district, which is adjacent to Tae-an national ocean park, is the Place where gas a natural advantage. However, in the result of the rural exodus follwed by industrialization, the population in this province are decreased rapidly and it still be on the process of the rural exodus. Hence, the total number of students, each school is under 100 at the moment and the number will be less in the future. Under this consequences, the rearrangement of these school is inevitable. For the new modernized school plan Narnmyun district, estimate the scale of school on the basis of decreased number of students, the analysis the 7th education plan and the questionnaire and face-to-face interview investigation, which is a resident-orented investigation, were carried out preferentially. The major research contents are as follows; o Expansion of schools facility and space for operating the 7th education plan(classified level schools level and subject-based class school plan) o Over-all improvement of educational environment to take all-out advantages of school, social and home education. o The school which can take a part of an educational center of a rural community in schools off-time-after school and summer and winter vocation. o The school which is related to the local cultural, sports and entertainment utility, On the basis of this research, the basic concept and purpose of a new school model model plan in Nammyun will be established and the new school plan represented for the result of this research.

• Geophysics and Geophysical Exploration
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• 제10권4호
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• pp.308-313
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• 2007

The small-loop electromagnetic technique has been used successfully for many geophysical qualitative investigations, particularly for shallow engineering and environmental surveys. Recently, various geophysical imaging methods based on numerical modeling and inversion have been tried in order to get more quantitative subsurface structure. However, conventional 2.5D small loop EM modeling takes a lot of time because responses should be calculated for several wave numbers and transformed into space domain. In this study, we developed a 2.5D HCP small loop EM modeling algorithm using extended Born approximation, which does not require transformation. Also, we checked its validity by comparison with other numerical results.

• Journal of Life Science
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• 제25권4호
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• pp.369-375
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• 2015

Data on the spatial distribution of a plant population among administrative areas is useful for various purposes. In this study, I analyzed the spatial distribution of the geographical distances of Carex siderosticta at Mt. Geumjeong and Mt. Ahop in Korea. The aim was to test a spatial structure within two populations of C. siderosticta. Most natural plots of C. siderosticta are not uniformly distributed in the forest community; for example, uniform plots were aggregately distributed within a space of 6.0 m $\times$ 6.0 m. When the sampling plots were larger than 6.0 m $\times$ 12.0 m, the individuals of C. siderosticta were aggregately distributed. The neighboring patches of C. siderosticta were predominantly 7.5 m to 9.0 m apart, on average; however, if the natural populations were disturbed by human activities, the aggregation occurred in shorter distances than a scale of 9.0 m. Moran's I of C. siderosticta significantly differed from the expected value in only 16 of 40 cases (40%). In conclusion, the geographical distribution of C. siderosticta is not even, with varying degrees of size in the plots, while human activities give rise to density effects in the plots at both Mt. Geumjeong and Mt. Ahop in Korea.

• Journal of Families and Better Life
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• 제28권6호
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• pp.81-94
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• 2010

This qualitative research was designed to explore the use of housing among Korean Chinese people in Harbin, China. Focusing on the use which based on the epistemology of housing adjustment, this was particularly designed to examine its cultural assimilation and acculturation on the way of life course, it employed the in-depth interview on the oral history of 5 interviewees in their 60s and 70s, individualized interviews were conducted from May 28 to 31 in 2010. Key findings were summarized as follows; 1. The free market reform in China resulted in privatization that allowed respondents to become homeowners, and the ownership was viewed as part of family asset centered upon a sense of solidarity. 2. Although homeowners in multi-story houses were responsible to decorate interior spaces, the common features in using interior spaces were found: entrance had no thresholds; kitchen was small, lack of storage cabinets, tile-flooring; washers were installed inside bathroom; and newly built apartment didn't have proper space to store Korean fermented foods. It was observed that housing adaptation outweighed housing adjustment. Those who used to live in Chinese houses with indoor-wearing-shoes or Russian houses with indoor-wearing-slippers were receptive to the use of dining table and bed, and the community heating system discouraged the use of individual electric water heater because of high electricity cost. 3. In daily life, eating habit wasn't much changed to the Chinese style, meals were shared, dish sterilizer was popular, and Kimchi fridge wasn't used. Because of the influence of the Chinese culture, such Korean traditions as ancestral rites and bedroom allocation tradition faded away, but traditional family values remained unchanged. In conclusion, Korean Chinese people experience normative housing deficits and adaptation selectively incurred. It's implied that residential design meets the needs resulting from the dual culture in terms of cultural assimilation and acculturation.

• Journal of the Korean Institute of Rural Architecture
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• 제12권1호
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• pp.25-32
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• 2010

The aim of this thesis is to present why the business district of old downtown in Jejusi collapsed and what sort of problems caused by that as collecting objective data, which help us to comprehend how the commercial zone has been decaying, on the physical state of the specific area near 'Sinheungro' and 'Chilsungro', which are main commercial sites in the downtown, and analysing it. Firstly It was revealed that most land investigated was property in which structure was able to built or poor land within $60m^2$. This was caused by increasing in land value and high density in space use so that the area did not develop. Secondly, In addition to be low density, most of buildings in 'Sinheungro' and 'Chilsungro' were so old and inefficient - the old buildings were abandoned without improving due to expensive rent and complicated property rights. Thirdly, According to the survey accomplished, major commercial facilities in the area have struggled with the continuous recession in their business. It was the inevitable result of not having an effective alliance with surrounding retail shops and a lack of a strategic action for satisfying consumers desire or adapting to new shopping patterns. Fourthly, Infrastructure in the site was ruining the beauty of the urban landscape as well as bringing on bad access to the inner city as not having improved enough. Furthermore, many administration departments which were in charge of each infrastructure existed. This was resulted from not considering unification between each infrastructure and regional characteristics of the local community.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.33-37
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• 2006

Since 1993, the civil aviation community through RTCA (Radio Technical Commission for Aeronautics) and the ICAO (International Civil Air Navigation Organization) have been working on the definition of GNSS augmentation systems that will provide improved levels of accuracy and integrity. These augmentation systems have been classified into three distinct groups: Aircraft Based Augmentation Systems (ABAS), Space Based Augmentation Systems (SBAS) and Ground Based Augmentation Systems (GBAS). The last one is an implemented system to support Air Navigation in CAT-I approaching operation. It consists of three primary subsystems: the GNSS Satellite subsystem that produces the ranging signals and navigation messages; the GBAS ground subsystem, which uses two or more GNSS receivers. It collects pseudo ranges for all GNSS satellites in view and computes and broadcasts differential corrections and integrity-related information; the Aircraft subsystem. Within the area of coverage of the ground station, aircraft subsystems may use the broadcast corrections to compute their own measurements in line with the differential principle. After selection of the desired FAS for the landing runway, the differentially corrected position is used to generate navigation guidance signals. Those are lateral and vertical deviations as well as distance to the threshold crossing point of the selected FAS and integrity flags. The Department of Applied Science in Naples has create for its study a virtual GBAS Ground station. Starting from three GPS double frequency receivers, we collect data of 24h measures session and in post processing we generate the GC (GBAS Correction). For this goal we use the software Pegasus V4.1 developed from EUROCONTROL. Generating the GC we have the possibility to study and monitor GBAS performance and integrity starting from a virtual functional architecture. The latter allows us to collect data without the necessity to found us authorization for the access to restricted area in airport where there is one GBAS installation.