• The Journal of Advanced Prosthodontics
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• v.10 no.4
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• pp.328-334
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• 2018

PURPOSE. To evaluate the reproducibility of scan-based abutments using a blue light model scanner. MATERIALS AND METHODS. A wax cast abutment die was fabricated, and a silicone impression was prepared using a silicone material. Nine study dies were constructed using the prepared duplicable silicone, and the first was used as a reference. These dies were classified into three groups and scanned using a blue light model scanner. The first three-dimensional (3D) data set was obtained by scanning eight dies separately in the first group. The second 3D data set was acquired when four dies were placed together in the scanner and scanned twice in the second group. Finally, the third 3D data set was obtained when eight dies were placed together in the scanner and scanned once. These data were then used to define the data value using third-dimension software. All the data were then analyzed using the non-parametric Kruskal-Wallis H test (${\alpha}=.05$) and the post-hoc Mann-Whitney U-test with Bonferroni's correction (${\alpha}=.017$). RESULTS. The means and standard deviations of the eight dies together were larger than those of the four dies together and of the individual die. Moreover, significant differences were observed among the three groups (P<.05). CONCLUSION. With larger numbers of abutments scanned together, the scan becomes more inaccurate and loses reproducibility. Therefore, scans of smaller numbers of abutments are recommended to ensure better results.

• Geomechanics and Engineering
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• v.22 no.4
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• pp.319-328
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• 2020

This paper investigates the effect of the width of failure and tension crack (TC) on the stability of cohesive-frictional soil slopes in three dimensions. Working analytically, the slip surface and the tension crack are considered to have spheroid and cylindrical shape respectively, although the case of tension crack having planar, vertical surface is also discussed; the latter was found to return higher safety factor values. Because at the initiation of a purely rotational slide along a spheroid surface no shear forces develop inside the failure mass, the rigid body concept is conveniently used; in this respect, the validity of the rigid body concept is discussed, whilst it is supported by comparison examples. Stability tables are given for fully drained and fully saturated slopes without TC, with non-filled TC as well as with fully-filled TC. Among the main findings is that, the width of failure corresponding to the minimum safety factor value is not always infinite, but it is affected by the triggering factor for failure (e.g., water acting as pore pressures and/or as hydrostatic force in the TC). More specifically, it was found that, when a slope is near its limit equilibrium and under the influence of a triggering factor, the minimum safety factor value corresponds to a near spherical failure mechanism, even if the triggering factor (e.g., pore-water pressures) acts uniformly along the third dimension. Moreover, it was found that, the effect of tension crack is much greater when the stability of slopes is studied in three dimensions; indeed, safety factor values comparable to the 2D case are obtained.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9C
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• pp.537-545
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• 2011

This paper analyzed performance of three dimensional turbo code and turbo ${\Phi}$ codes proposed in the next generation DVB-RCS systems. In the view of turbo ${\Phi}$ codes, we proposed the optimal permutation and puncturing patterns for triple binary input data. We also proposed optimal post-encoder types and interleaving algorithm for three dimensional turbo codes. Based on optimal parameters, we simulated both turbo codes, and we confirmed that the performance of turbo ${\Phi}$ codes are better than that of three dimensional turbo codes. However, the complexity of turbo ${\Phi}$ is more complex than that of three dimensional turbo codes by 18%.

• Journal of Korean Academy of Nursing
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• v.13 no.3
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• pp.106-118
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• 1983

The main purpose of this study is to systematically classify words indicating pain in terms of their ranks in each subclass. This study is a part of developing a Korean Pain Measurement Tool. This study didnot include exploration of each word's dimension such as sensory or affective. Eighty three Korean words tentatively classified in 19 subclasses in previous study were used for this study. At least three to six words were included in each subclass and the words were randomly placed in which each subject indicates their rank of pain degree. One hundred and fifty nursing students and one hundred clinical nurses were requested to indicate the rank of each word. One hundred and sixteen students and eighty three nurses completed the ratings for analysis. The data were collected from June 1983 to July 1983. The data using ordinal scale were analyzed by Friedman ANOVA to test significant difference between rank means. All of pain words indicated significant rank mean difference in all of 19 subclasses. Some of the words were either cancelled or replaced by other words, or rearranged for their ranks. Subclasses of which words were cancelled were 1) Simple stimulating pain, 2) Punctuate pressure, 3) peripheral nerve pain, 4) radiation pain, 5) punishment-related pain, and 6) suffering-related pain. Subclasses of which words were replaced or rearranged were 1) incisive pressure, 2) constrictive pressure, 3) dull pain, 4) tract pain, 5) digestion-related pain and 6) fear-related pain. Four subclasses such as traction pressure, thermal, cavity pressure, and fatigue- elated pain indicated significant differences among rank means in each subclasses and showed no visible overlaps of the ranks among means. Further research is needed using high level measurement of pain degree of each word and more sophisticated analysis of the pain degrees. Three pain words which would be related to chemical stimulation were newly explored and included as a new subclass. Through this study, the total number of subclasses increases from 19 to 20 and the total number of Korean words in the scale decreases from 83 to 80.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.2
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• pp.159-164
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• 2008

This study simulated the flood inundations of the Nakdong River catchment running through Yangsan, a small city located in the south eastern area of Korea by using the depth averaged two-dimensional hydrodynamic numerical model. The numerical model employs the staggered grid system including moving boundary and a finite different method to solve the Saint-Venant equations. A second order upwind scheme is used to discretize the nonlinear convection terms of the momentum equations, whereas linear terms are discretized by a second order Leap-frog scheme(Cho and Yoon, 1998). The numerical model was applied to a real topography to simulate the flood inundation of the Yangsan basin in Yangsan. The numerical result for urban district was visualization for three dimension. These results can be essentially utilized to construct the three dimensional inundation map after building the GIS-based database in local public organizations in order to protect the life and property safely.

• Journal of the Daesoon Academy of Sciences
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• v.34
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• pp.171-202
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• 2020

The nations of East Asia have similar historical backgrounds in terms of going through modernization during the nineteenth century. All of them commonly experienced socio-political hardships. Three of the most prosperous East Asian new religions, Yiguandao, Tenrikyo, and Daesoon Jinrihoe, all emerged under similar socio-political circumstances during the nineteenth century. There was no mutual interchange, but the cosmological perspectives share some analogous ideology. All of them were types of nativist millennialism. The ultimate goal in all three is redeeming lost elements by magical means-the sudden disappearance of invading forces, the return of mystical heroes or messiahs, and an altered landscape. As Stark said, although it is impossible to calculate the actual rate of success, probably no more than one religious movement out of 1,000 will attract more than 100,000 followers and last for as long as a century. By this standard, these three groups are certainly worthy of being studied. This paper will examine and compare these three groups through four dimensions: the Messiah's eschatology, the re-interpretation of that eschatology after the Messiah's death, the rational transformations of millennial dreams, and the institutionalization of those millennial dreams. Analytically, I could demonstrate the differences among these groups through two dimensions: (1) The dimension of time, which can be conceptualized in terms of this-worldly or other-worldly; and (2) Collective vision, which can be conceptualized in terms of utopia or reform. The cross-classification of these two dimensions is suggestive of the general avenues of Millennialism. Through these comparisons and observations, light will be shed on the essence and dynamics of East Asian Millennialist Thought by exploring deeper cultural implications.

• Progress in Medical Physics
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• v.23 no.3
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• pp.145-153
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• 2012

In this study, we quantify the residual motion artifact in 4D-CT scan using the dynamic lung phantom which could simulate respiratory target motion and suggest a simple one-dimension theoretical model to explain and characterize the source of motion artifacts in 4DCT scanning. We set-up regular 1D sine motion and adjusted three level of amplitude (10, 20, 30 mm) with fixed period (4s). The 4DCT scans are acquired in helical mode and phase information provided by the belt type respiratory monitoring system. The images were sorted into ten phase bins ranging from 0% to 90%. The reconstructed images were subsequently imported into the Treatment Planning System (CorePLAN, SC&J) for target delineation using a fixed contour window and dimensions of the three targets are measured along the direction of motion. Target dimension of each phase image have same changing trend. The error is minimum at 50% phase in all case (10, 20, 30 mm) and we found that ${\Delta}S$ (target dimension change) of 10, 20 and 30 mm amplitude were 0 (0%), 0.1 (5%), 0.1 (5%) cm respectively compare to the static image of target diameter (2 cm). while the error is maximum at 30% and 80% phase ${\Delta}S$ of 10, 20 and 30 mm amplitude were 0.2 (10%), 0.7 (35%), 0.9 (45%) cm respectively. Based on these result, we try to analysis the residual motion artifact in 4D-CT scan using a simple one-dimension theoretical model and also we developed a simulation program. Our results explain the effect of residual motion on each phase target displacement and also shown that residual motion artifact was affected that the target velocity at each phase. In this study, we focus on provides a more intuitive understanding about the residual motion artifact and try to explain the relationship motion parameters of the scanner, treatment couch and tumor. In conclusion, our results could help to decide the appropriate reconstruction phase and CT parameters which reduce the residual motion artifact in 4DCT.

• Journal of the Korean Solar Energy Society
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• v.26 no.2
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• pp.1-7
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• 2006

A numerical investigation was performed to determine the effect of airfoil on the optimum flap height using NACA0015 Wells turbine. The five double flaps which have 0.5% difference were selected. A Navier-Stokes code, CFX-TASCflow, was used to calculate the flow field of the Wells turbine. The basic feature of the Wells turbine is that even though the cyclic airflow produces oscillating axial forces on the airfoil blades, the tangential force on the rotor is always in the same direction. Geometry used to define the three dimension numerical grid is based upon that of an experimental test rig. This paper tries to disign the double flap of Wells turbine with the numerical analysis.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2857-2861
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• 2007

Flow and aerodynamic characteristics were analyzed numerically for a commercial passenger airplane, Boeing 747-400, flying in the cruising condition. The model geometry with 100:1 in scale was obtained by the photo scanning measurement with the maximum error of 1.4% comparing with the real airplane dimension. The three-dimensional inviscid steady compressible governing equations were solved by the finite volume method in the unstructured grid system. The convective terms were treated by the Crank-Nicholson and first-order upwind schemes. In the computational results, the strong wing-tip vortices were clearly observed and the pressure contours on the airplane surface were suggested. The lift and drag forces in the wing with engines increase by 1.49% and 3.9%, respectively compared with the case without engines. The aerodynamic forces were estimated quantitatively for each element which consists of the airplane.

• Journal of the Korean Institute of Educational Facilities
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• v.14 no.4
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• pp.14-24
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• 2007

Recently, there are three major trends in building school facilities by government. First trend is to reconstruct facilities that have been built for 30 years. Second is the creation of a new town, new construction demanded from the redeveloping area. Finally, third is to build educational convenience facilities such as gymnasium, auditorium and cafeteria etc. When building or reconstructing school facilities, it is important to consider the 7th Education curriculum. The purpose of this study is to propose the guide line of the planning the dimension of Science Laboratory in in elementary school, corresponding to teaming contents and method.