• The korean journal of orthodontics
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• v.44 no.2
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• pp.62-68
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• 2014

Objective: The purpose of this study was to examine the symmetry and parallelism of the skeletal and soft-tissue poria by three-dimensional (3D) computed tomographic (CT) imaging. Methods: The locations of the bilateral skeletal and soft-tissue poria in 29 patients with facial asymmetry (asymmetric group) and 29 patients without facial asymmetry (symmetric group) were measured in 3D reconstructed models of CT images by using a 3D coordinate system. The mean intergroup differences in the anteroposterior and vertical angular deviations of the poria and their anteroposterior and vertical parallelism were statistically analyzed. Results: The symmetric and asymmetric groups showed significant anteroposterior angular differences in both the skeletal and the soft-tissue poria (p = 0.007 and 0.037, respectively; Mann-Whitney U-test). No significant differences in the anteroposterior and vertical parallelism of the poria were noted ($p{\leq}0.05$; Wilcoxon signed-rank test). Conclusions: In general, the skeletal poria are parallel to the soft-tissue poria. However, patients with facial asymmetry tend to have asymmetric poria.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.181-186
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• 1999

Recently the machining technique have been progressed rapidly according to developments of the product technique in the machine tool and new tools. But in the case of vertical machine center(VMC), to become visible there is the appearance of bending because of the structural problems of x-axis guide way, and this would effect directly on accuracy of form of the straightness, parallelism and flatness. In this paper, I purpose to check the appearance of bending with the experiment and improve the working accuracy. Under the constant working conditions, the appearance of bending of x-axis guide way was measured to confirm the effectiveness of the compensation method in the vertical machine center(VMC). By using this method the results show that the accuracy of form of the straightness, parallelism and flatness could be reduced to 20% compared with ordinary method.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.1
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• pp.161-169
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• 1989

A stability problem on wave instability of natural convection flow along isothermal vertical cylindrical surfaces has been formulated, accounting for the non-parallelism of the basic flow and thermal fields. Then the problem is solved numerically under the simplifying assumption of the parallelism of the basic flow quantities. It is shown that the flow corresponding to the same characteristic boundary layer thickness becomes more stable as the value of the curvature parameter increases. The stability characteristics for Pr=0.7 appear to be more sensitive to the curvature parameter than those for Pr=7.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.3
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• pp.238-245
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• 2014

In order to create denture occlusion that is functional, comfortable and balanced, it is necessary to both determine a vertical dimension of occlusion that is in harmony with the patient's musculature and to record a relatively repeatable jaw relation position. This require clinical skill to establish an accurate, verifiable and reproducible vertical dimension of occlusion (VDO) and centric relation (CR). Correct vertical relation depends upon a consideration of several factors, including muscle tone, inter-dental arch space and parallelism of the ridges. Centric relation is considered to be a repeatable position from which all opening and lateral mandibular movements begin and recording this position is a critical step in the fabrication of dentures. Any errors made while taking maxillo-mandibular jaw relation records will result in denture that are uncomfortable. The purpose of this paper is to review a very simple and efficient technique for accomplishing these two important steps in denture fabrication.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.699-706
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• 2008

H.264/AVC is a new international standard for the compression of video images, in which a deblocking filter has been adopted to remoye blocking artifacts. This paper proposes an efficient architecture of deblocking filter in H.264/AVC. By making good use of data dependence between neighboring $4{\times}4$ blocks, the memory sire is reduced and the throughput of the deblocking filter processing is increased. The designed deblocking filter further enhances the parallelism by simultaneously executing horizontal and vertical filtering within a macroblock in pipeline method and adopting overlap between macroblocks. The implementation result shows that the proposed architecture enhances the performance of deblocking filter processing from 1.75 to 4.23 times than that of the conventional deblocking filter. Hence the Proposed architecture of deblocking filter is able to perform real-time deblocking in high-resolution($2048{\times}1024$) video applications.

• Journal of Broadcast Engineering
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• v.17 no.5
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• pp.742-755
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• 2012

In this paper, we propose a parallel deblocking algorithm to resolve workload imbalance when the deblocking filter of high efficiency video coding (HEVC) decoder is parallelized. In HEVC, the deblocking filter which is one of the in-loop filters conducts two-step filtering on vertical edges first and horizontal edges later. The deblocking filtering can be conducted with high-speed through data-level parallelism because there is no dependency between adjacent edges for deblocking filtering processes. However, workloads would be imbalanced among regions even though the same amount of data for each region is allocated, which causes performance loss of decoder parallelization. In this paper, we solve the problem for workload imbalance by predicting the complexity of deblocking filtering with coding unit (CU) depth information at a coding tree block (CTB) and by allocating the same amount of workload to each core. Experimental results show that the proposed method achieves average time saving (ATS) by 64.3%, compared to single core-based deblocking filtering and also achieves ATS by 6.7% on average and 13.5% on maximum, compared to the conventional uniform data-level parallelism.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.185-194
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• 2001

This study was designed to evaluate the effects of angulation changes of head posture on the enlargement ratios of a lateral headfilm depending on the vortical or horizontal rotation of the objects. A device was constructed to measure regional changes of enlargement ratios. The device was held within the cephalostat and cephalograms recorded at each measured degrees of the device tilting, vertically and horizontally. The enlargement ratios of the horizontal, vertical, and angular measurements on the films taken at each tilted angulations were obtained and compared with those on the films taken without rotation. In summary, the enlargement ratios of the horizontal linear measurements were decreased during horizontal rotations. The enlargement ratios of vortical measurements of the right side on the film were increased and those of the left side were decreased by the horizontal rotations. Enlargement ratios of horizontal measurements were affected further than those of vertical measurements by the same angular changes of the horizontal rotations. Therefore, a disruption of parallelism between the object's midsagittal plane and the film could result in distortion of the image while vertical rotation around the object's porionic axis would not significantly affect the enlargement ratios on the headfilm.

• The korean journal of orthodontics
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• v.38 no.4
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• pp.240-251
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• 2008

Objective: The purpose of this study was to evaluate the effect of head position changes on the root parallelism between adjacent teeth on panoramic radiographs. Methods: A model with normal occlusion was constructed in the SolidWorks program, then RP (rapid protyping) model was fabricated. The model was repeatedly imaged and repositioned five times at each of the following nine positions: ideal head position, $5^{\circ}$ up, $10^{\circ}$ up, $5^{\circ}$ down, $10^{\circ}$ down, $5^{\circ}$, right, $10^{\circ}$, up, and $5^{\circ}$ right rotation, $10^{\circ}$ right rotation. Panoramic radiographs were taken by Planmeca ProMax and the angle between the long axes of adjacent teeth was directly measured in the monitor. Results: Axes of adjacent teeth tended to converge toward the occlusal plane when the head tilted up and converged in the opposite direction to the occlusal plane when the head tilted down. Anterior teeth showed the most notable differences. When one side of the head tilted up $5^{\circ}$ and $10^{\circ}$ along the anteroposterior axis (Y axis), tooth axes of the same side tended to converge toward the occlusal plane and tooth axes of the opposite side tended to converge in the opposite direction to the occlusal plane. When the head rotated to one side along the vertical axis (Z axis), the canine and lateral incisor of the same side converged in the opposite direction to the occlusal plane and the canine and lateral incisor of the other side converged toward the occlusal plane. Conclusions: When assessing the root parallelism on panoramic radiographs, the occlusal plane cant (anteroposterior or lateral) or asymmetry of the dental arch should be considered because these can cause distortion of tooth axes on panoramic radiographs.

• ETRI Journal
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• v.42 no.4
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• pp.596-607
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• 2020

Scaling is an important operation because of the iterative nature of arithmetic processes in digital signal processors (DSPs). In residue number system (RNS)-based DSPs, scaling represents a performance bottleneck based on the complexity of intermodulo operations. To design an efficient RNS scaler for special moduli sets, a body of literature has been dedicated to the study of the well-known moduli sets {2ⁿ - 1, 2ⁿ, 2ⁿ + 1} and {2ⁿ, 2ⁿ - 1, 2ⁿ⁺¹ - 1}, and their extension in vertical or horizontal forms. In this study, we propose an efficient programmable RNS scaler for the arithmetic-friendly moduli set {2^n+p, 2ⁿ - 1, 2ⁿ⁺¹ - 1}. The proposed algorithm yields high speed and energy-efficient realization of an RNS programmable scaler based on the effective exploitation of the mixed-radix representation, parallelism, and a hardware sharing technique. Experimental results obtained for a 130 nm CMOS ASIC technology demonstrate the superiority of the proposed programmable scaler compared to the only available and highly effective hybrid programmable scaler for an identical moduli set. The proposed scaler provides 43.28% less power consumption, 33.27% faster execution, and 28.55% more area saving on average compared to the hybrid programmable scaler.

• The KIPS Transactions:PartA
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• v.13A no.2 s.99
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• pp.171-176
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• 2006

In this paper, we develop energy efficient designs for the Fast Fourier Transform (FFT) on FPGAs. Architectures for FFT on FPGAs are designed by investigating and applying techniques for minimizing the energy dissipation. Architectural parmeters such as degrees of vertical and horizontal parallelism are identified and a design choices. We determine design trade-offs using high-level performance estimation to obtain energy-efficient designs. We implemented a set storage types as parameters, on Xilinx Vertex-II FPGA to verify the estimates. Our designs dissipate 57% to 78% less energy than the optimized designs from the Xilinx library. In terms of a comprehensive metric such as EAT (Energy-Area-Time), out designs offer performance improvements of 3-13x over the Xilinx designs.