• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.385-390
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• 2005

A specimen with residual stress due to welding was analyzed by three-dimensional cohesive zone model. The residual stress distribution was calculated by simulating welding process, and cohesive elements were located along crack propagation planes. Crack growth is possible since two planes of the cohesive element are separated beyond a maximum load carrying capacity. Stress fields around a crack tip are compared for specimens with and without residual stresses. Load-displacement curves and crack growth behaviors are also examined.

• 대한수학회보
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• 제54권5호
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• pp.1719-1724
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• 2017

In this note, companion to the paper [10], we describe an alternative method for finding Laurent polynomials mirror-dual to complete intersections in Grassmannians of planes, in the sense discussed in [10]. This calculation follows a general method for finding torus charts on Hori-Vafa mirrors to complete intersections in toric varieties, detailed in [5] generalising the method of [8].

• Communications for Statistical Applications and Methods
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• 제20권1호
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• pp.77-84
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• 2013

This paper deals with the relative efficiency of two kernel estimators $\hat{f}_n$ and $\hat{g}_n$ by using spherical data, as proposed by Park (2012), and Bai et al. (1988), respectively. For this, we suggest the computing flows for the relative efficiency on the 2-dimensional unit sphere. An evaluation procedure between two estimators (given the same kernels) is also illustrated through the observed data on normals to the orbital planes of long-period comets.

• 대한수학회지
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• 제61권3호
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• pp.445-459
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• 2024

In this paper, by establishing the direct method of moving planes for the fractional Laplacian system with positive-negative mixed powers, we obtain the radial symmetry and monotonicity of the positive solutions for the fractional Laplacian systems with positive-negative mixed powers in the whole space. We also give two special cases.

• Kyungpook Mathematical Journal
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• 제26권2호
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• pp.217-222
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• 1986

• 정보처리학회논문지B
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• 제11B권4호
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• pp.395-402
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• 2004

본 논문은 비트 플레인별 적응적 임계값을 이용한 대용량 스테가노그라피 방법을 제안하였다. 모든 비트 플레인에 고정적인 임계값을 적용하여 정보를 삽입하면, 비트 플레인에 따라 화질의 열화가 생긴다. 따라서 본 논문에서는 고정 임계값의 문제점을 해결하기 위하여 비트 플레인별 가중치를 정의하였다. 그리고 비트 플레인의 삽입 용량을 적응적으로 증가시키기 위하여, 비트 플레인별 평균 복잡도와 가중치를 이용하여 새로운 적응적 임계값 설정 방법을 제안하였다. 실험에서는 각 표준 이미지에 동일한 화질과 정보량을 삽입하고, 이에 따른 삽입 용량과 화질을 비교하였다. 그 결과, 제안한 방법이 기존의 방법보다 삽입 용량면에서 평균 약 6%의 정도 증가되었고, 화질면에서도 평균 약 2.4dB 향상되었다.

• 대한전자공학회논문지SP
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• 제42권3호
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• pp.41-50
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• 2005

도심지 풍경을 3 차원 가시화 하는데 적합한 새로운 모자이크 방법을 제안하였다. 도심지에서 도로를 따라 촬영한 일련의 영상들을 2 차원 모자이크하면 입체감이 느껴지지 않는다. 제안한 방법은 도심지의 도로를 따라 나타나는 물체들을 연속 촬영하여, 이 영상들을 대표하는 복수의 투영평면들을 구한 후, 도로를 따라 촬영한 영상들을 이 복수의 평면들에 투영함으로써 입체감을 얻게 하는 것이다. 이를 위해서 연속 촬영한 영상들 간의 특징 점들을 정합함으로써 3 차원으로 표현된 복수의 투영면을 우선 얻는다. 이 복수의 평면들은 인접 평면 간에 상호 연결하여 물체들의 개략적 윤곽 면을 구성하는데, 이 복수 평면에 2 차원 영상들을 투영함으로써 영상에 대한 입체감을 부여하는 기술이다. 이 논문에서 실제 도심지 영상을 3 차원 가시화 시키는 알고리즘에 대한 데모를 보였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권4호
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• pp.346-351
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• 2011

Purpose: The purpose of this study was to measure the angular differences between the horizontal reference planes on the CBCT generated PA cephalogram and the modified interpupillary plane, which was usually used in the clinical examination, and to evaluate the validity of the horizontal reference planes. Methods: The CBCT generated PA cephalogram was used to measure the angles between the FH, Lo and IP planes. The subjects consisted of 42 patients with facial asymmetry (males: 21, females: 21, mean-age: 21.6 years). The control groups were also assessed (males: 10, females: 10, mean-age: 23.8 years). The distance of the interpupil was measured on the soft-tissue volume rendered image. The angular differences were statistically analyzed using the $Mann-Whitney$ $U$ $test$ for inter-group comparisons and the $Friedman$ $test$ for intra-group comparisions. Results: The angle between the FH plane and IP plane (the angle of the FH-IP line) showed a statistically significant difference between the two groups ($p$ <0.05). There was no statistical differences between each angle (angle of the FH-IP line, angle of the FH-Lo line, angle of the Lo-IP line) on the intra-group comparision ($p$ >0.05). Conclusion: The angle between the Lo line and IP line (angle of the Lo-IP line) showed no statistically significant difference in both the control and asymmetry groups. Therefore, the Lo line could be used as a horizontal reference plane in CBCT generated PA cephalograms.

• 대한치과보철학회지
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• 제36권2호
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• pp.293-301
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• 1998

The purpose of this study was to investigate the effects of load on root that was applied to edentulous area in three simulated situation, in each case the guiding planes of abutment were right vertical, 95 degrees, or 100 degrees to residual ridge. The 2-dimensional finite element method was used and the finite element model was prepared as fellows. Right mandibular 1st and 2nd molar was lost and the 2nd premolar with distal rest was used as primary abutment which had three different degrees of guiding plane. Then 150N of compressive force was applied to central fossae of the 1st and 2nd molars and von Mises stress and displacement was measured. The results were as follows; 1. Irrespective of slopes of guiding planes, the stress was concentrated on mesial side of root apex and distal side of coronal portion of root, in particular on junction with distal alveolar bone. As slopes of guiding planes were increased. stress on root and compact bone surrounding abutment was increased but no considerable effect was seen on compact bone of residual ridge. 2. Distal side of coronal portion of root limited by periodontal ligament was displaced distally and mesial side of apical portion was mesially. With slope of guiding plane increasing, the pattern of displacement was similar with one another but the quantity was increased. 3. Both abutment & alveolar bone were displaced downward and root of abutment, especially distal side of coronal portion, was displaced severely. As the guiding plane was tiffed more mesially over $90^{\circ}$, the degree of displacement was also increased.

• Archives of Plastic Surgery
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• 제39권4호
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• pp.354-359
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• 2012

Background During the planning of a thoracodorsal artery perforator (TDAP) free flap, preoperative multidetector-row computed tomographic (MDCT) angiography is valuable for predicting the locations of perforators. However, CT-based perforator mapping of the thoracodorsal artery is not easy because of its small diameter. Thus, we evaluated 1-mm-thick MDCT images in multiple planes to search for reliable perforators accurately. Methods Between July 2010 and October 2011, 19 consecutive patients (13 males, 6 females) who underwent MDCT prior to TDAP free flap operations were enrolled in this study. Patients ranged in age from 10 to 75 years (mean, 39.3 years). MDCT images were acquired at a thickness of 1 mm in the axial, coronal, and sagittal planes. Results The thoracodorsal artery perforators were detected in all 19 cases. The reliable perforators originating from the descending branch were found in 14 cases, of which 6 had transverse branches. The former were well identified in the coronal view, and the latter in the axial view. The location of the most reliable perforators on MDCT images corresponded well with the surgical findings. Conclusions Though MDCT has been widely used in performing the abdominal perforator free flap for detecting reliable perforating vessels, it is not popular in the TDAP free flap. The results of this study suggest that multiple planes of MDCT may increase the probability of detecting the most reliable perforators, along with decreasing the probability of missing available vessels.