• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.75-84
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• 2008

The purpose of this research is to find the visual characteristics and geographic structure in a landscape of mountains in Yangsan City. In order to carry out this study, 40 view points of 6 mountains in Yangsan City were selected to experience the mountainscape. The results are as follows. The mountainscape of Yangsan City was confirmed from the view point to the object of view as ranging in middle distance reverse, the angle of elevation 11${\sim}13^{\circ}$ which give the impression of confronted to the mountain, and the horizontal angle 50${\sim}90^{\circ}$ which gives the impression of vastness. This shows that mountainscapes are perceived impressively when seeing the mountain with the meaning to feel the texture of the mountain as a confrontational relationship rather than a pictorial relationship. The geographic structure of the view point which occurs in scenes of impressive experience is classified into eight types and its characteristics are investigated. The first type is corridor, and it emerges in a long narrow linear structure made from the surrounding environment with buildings or street trees. The second is tunnel in which a vision and light hidden while passing underneath a bridge, high-level road, or inside a tunnel can be seen. Third, the maze is formed by the mountain shape. The hill spur emerges when the direction of traffic changes after turning the coner of a building or mountain edge. The hill ground emerges at the top of a hill slope. Next, parallel emerges when the observer and the mountain are in the same direction of process. Confrontation occurs when confronting an isolated mountain. Finally, the view point emerges when passing through major points such as a bridge or square and the boundary of a village or city. This research arranged visual conditions that create impressive mountainscapes. Geographic characteristics in terms of Types that make possible to experience mountainscapes were described. The results of this research will be basic data collected for the management and preservation of mountainscapes and for landscape effect evaluation. Furthermore, this research suggests theoretical evidence to preserve and manage geographic structures that create view experiences as well as to preserve the landscape in terms of view points.

• Journal of the Korean earth science society
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• v.31 no.3
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• pp.214-224
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• 2010

Gravity and Magnetic survey data were analyzed to investigate the geophysical characteristics and regional geological structures of the southwestern Yellow Sea. The set of data about the southwestern part of the Yellow Sea in Korea was one collected by the Korea Ocean Research and Development Institute (KORDI) in 2003, 2004, and 2005. The Yellow Sea has a few basins and the study area also includes parts of the Heuksan Basin and the East China Sea Basin. The bathymetry of the study area ranges from about ?40 m southwestward near China to about 150 m northeastward near Korea. The bathymetry has the gentle rise and fall and the smooth slope. The gravity anomalies, from sea surface gravity and satellite gravity data, reflect the basement rocks rather than the smooth bathymetry. The gravity anomalies are higher on Northeastern part of the study area and lower over the South of the Heuksan Basin. The analytic signal from the Bouguer anomaly shows higher anomalous zones near the boundaries of the basins. The magnetic anomalies and the analytic signal, from the magnetic data, suggest that the complex anomalies on the Northern part are attributed to the volcanic intrusions and that the smooth patterns in the Southern part are based on the lack of the intrusions. The power spectrum analysis of the Bouguer anomalies and the magnetic anomalies indicate that the depth to the Moho discontinuity varies from about 30.2 to 28.3 km and that the depths of the basement rocks and the Eocene discontinuity range from about 8.4 to 8 km and from about 1.5 to 1.7 km, respectively. The inversion of the Bouguer anomaly shows that the Moho depth to the Western part of the study area near China is slightly deeper than the Eastern part near Korea. The result of 2-D gravity modeling has a good coherence with the results of the analytic signal, the power spectrum analysis, and the inversion.

• Korean Journal of Cognitive Science
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• v.15 no.4
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• pp.31-47
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• 2004

This study was carried out to examine the development of physical knowledge in children. Eighty children aged 3- to 11-year-old and 16 adults were participated in this study. Participants' knowledge about failing, sliding and sinking/floating objects was investigated to understand what kind of knowledge they had, whether their knowledge was organized as theory and what was the nature of the developmental change in physical knowledge. Results showed that, for falling object task children of all age had correct knowledge about object's falling phenomena. However, there were age differences in children's understanding of the cause of object's falling. As the children's age decreased, the frequency of explanation referring to the absence of supper rather than the gravity as the cause of falling phenomena increased. For the sliding object task, children of all age could predict the motion of sliding object correctly. But only a few 9- and 11-year-old children could understand the effect of object weight and relations between gravity, frictional force and their interactions. Children under age 7 showed no evidence of possessing these knowledge. For sinking or floating object task, children of all age and even adults showed difficulties in understanding the sinking or float phenomena per se. For the cause of these phenomena although a few 9- and 11-year-old children referred to buoyancy as the cause, they had no correct knowledge about the buoyancy. This was also true for the adults. As a conclusion, the results of this study suggested that, not 3, but as young as 5-year-old children's physical knowledge exited as a form of naive theory in terms of their use as a causal devise in explaining the cause of object motion. However, even the theory of 9- and 11-year-old children was lack of the abstractness and coherence, which were also important characteristics of a theory. Finally, developmental change in physical knowledge proceeded toward more frequent and consistent use of physical knowledge as causal device and more abstract and coherently organized theory.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.5
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• pp.528-534
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• 2008

Purpose: Marginal fit is one of the important components for the successful prosthodontic restoration. Poor fitting margin of the restoration causes hypersensitivity, secondary caries, and plaque accumulation, which later result in prosthodontic failure. CAD/CAM zirconia all-ceramic restorations, such as $LAVA^{(R)}$ (3M ESPE, St.Paul, MN) and $EVEREST^{(R)}$ (KaVo Dental GmbH, Biberach, Germany) systems were recently introduced in Korea. It is clinically meaningful to evaluate the changes of the marginal fit of the CAD/CAM zirconia systems before and after build-up. The purposes of this study are to compare the marginal fit of the two CAD/CAM all-ceramic systems with that of the ceramometal restoration, before and after porcelain build-up Material and methods: A maxillary first premolar dentiform tooth was prepared with 2.0 mm occlusal reduction, 1.0 mm axial reduction, chamfer margin, and 6 degree taperness in the axial wall. The prepared dentiform die was duplicated into the metal abutment die. The metal die was placed in the dental study model, and the full arch impressions of the model were made. Twenty four copings of 3 groups which were $LAVA^{(R)}$, $EVEREST^{(R)}$, and ceramometal restorations were fabricated. Each coping was cemented on the metal die with color-mixed Fit-checker $II^{(R)}$ (GC Cor., Tokyo, Japan). The marginal opening of each coping was measured with $Microhiscope^{(R)}$ system (HIROX KH-1000 ING-Plus, Seoul, Korea. X300 magnification). After porcelain build-up, the marginal openings of $LAVA^{(R)}$, $EVEREST^{(R)}$,and ceramometal restorations were also evaluated in the same method. Statistical analysis was done with paired t-test and one-way ANOVA test. Results: In coping states, the mean marginal opening for $EVEREST^{(R)}$ restorations was $52.00{\pm}11.94\;{\mu}m$ for $LAVA^{(R)}$ restorations $56.97{\pm}10.00\;{\mu}m$, and for ceramometal restorations $97.38{\pm}18.54\;{\mu}m$. After porcelain build-up, the mean marginal opening for $EVEREST^{(R)}$ restorations was $61.69{\pm}19.33\;{\mu}m$, for $LAVA^{(R)}$ restorations $70.81{\pm}12.99\;{\mu}m$, and for ceramometal restorations $1115.25{\pm}23.86\;{\mu}m$. Conclusion: 1. $LAVA^{(R)}$ and $EVEREST^{(R)}$ restorations in comparison with ceramometal restorations showed better marginal fit, which had significant differences (P < 0.05) in coping state and also after porcelain build-up . 2. The mean marginal opening values between $LAVA^{(R)}$ and $EVEREST^{(R)}$ restorations did not showed significant differences after porcelain build-up as well as in coping state (P > .05). 3. $EVEREST^{(R)}$, $LAVA^{(R)}$ and ceramometal restorations showed a little increased marginal opening after porcelain build-up, but did not show any statistical significance (P > .05).

• Economic and Environmental Geology
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• v.8 no.2
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• pp.73-87
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• 1975

Regional unconformities have been used as boundaries of major stratigraphic units in Korea. The term "synthem" has already been propsed for formal unconformity-bounded stratigraphic units of maximum magnitude (ISSC, 1974). The unconformity-based classification of the strata in the cratonic area in Korea comprises in ascending order the Kyerim, $Sangw{\check{o}}n$, $Jos{\check{o}}n$, $Py{\check{o}}ngan$, Daedong, and $Ky{\check{o}}ngsang$ Synthems, and the Cenozoic Erathem. The unconformites separating them from each other are either orogenic or epeirogenic (and vertical tectonic). The sub-$Sangw{\check{o}}n$ unconformity is a non-conformity above the basement complex in Korea. The unconformities between the $Sangw{\check{o}}n$, $Jos{\check{o}}n$, and $Py{\check{o}}ngan$ Synthems are disconformities denoting late Precambrian and Paleozoic crustal quiescence in Korea. The unconformities between the $Py{\check{o}}ngan$, Daedong, and $Ky{\check{o}}ngsang$ Synthems are angular unconformities representing Mesozoic orogenies. The bounding unconformities of the $Ky{\check{o}}ngsang$ Synthem involve non-conformable parts overlying the Jurassic and late Cretaceous granitic rocks.