• Journal of applied mathematics & informatics
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• 제42권5호
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• pp.1227-1236
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• 2024

The main aim of this paper is to suggest modified patch conditions for nonconforming mixed finite element(NMFE) method and introduce a new family of the NMFE space of higher order on parallelepiped grids. Also, we provide a framework for error estimates.

• 한국군사과학기술학회지
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• 제21권1호
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• pp.69-73
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• 2018

Korean-peacekeeper's transparent armors in Iraq showed delamination, cracking and clouding a decade ago. And there were also similar deterioration recurrences in KLTV during the operational test a few years ago. Also, the differences between operational capability & lab Bullet-proof test condition, and insufficiency of military protection spec resulted in incomplete bullet-proof results. Moreover, although so many ground weapon systems have been developed, there were not secure test & evaluation codes to verify transparent armoured glasses equal to advanced-overseas products. So in this study, first, environmental test codes were established that all tests should be carried out as the application of only one specimen with newly adopted thermal shock test instead of completing each test with different one. Second, protection standards were integrated through the analysis of global developed country's specifications and reinforced as adding to the real mock-up condition if vehicle's glasses are smaller than standard specimen. Hereby, by applying to test-codes which including actual operational & vehicular conditions, the gap between development test and operational environment was minimized.

• Nuclear Engineering and Technology
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• 제53권5호
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• pp.1391-1402
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• 2021

The aim of this work is to prepare a neutron noise calculator based on the second order of average current nodal expansion method (ACNEM). Generally, nodal methods have the ability to fulfill the neutronic analysis with adequate precision using coarse meshes as large as a fuel assembly size. But, for the zeroth order of ACNEM, the accuracy of neutronic simulations may not be sufficient when coarse meshes are employed in the reactor core modeling. In this work, the capability of second order ACNEM is extended for solving the neutron diffusion equation in the frequency domain using coarse meshes. For this purpose, two problems are modeled and checked including a slab reactor and 2D BIBLIS PWR. For validating of results, a semi-analytical solution is utilized for 1D test case, and for 2D problem, the results of both forward and adjoint neutron noise calculations are exploited. Numerical results indicate that by increasing the order of method, the errors of frequency dependent coarse mesh solutions are considerably decreased in comparison to the reference. Accordingly, the accuracy of second order ACNEM can be acceptable for the neutron noise calculations by using coarse meshes in the nuclear reactor core.

• Imaging Science in Dentistry
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• 제43권2호
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• pp.71-75
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• 2013

Purpose: This study was performed to determine the position of the mental foramen relative to the apices of the teeth based on panoramic radiographs in a Moroccan population. We also analyzed gender differences and the symmetry of location within individuals. Materials and Methods: Seven hundred ninety-four panoramic radiographs were evaluated with regard to the location and symmetry of the mental foramina in male and female subjects. The results were analyzed using Pearson's ${\chi}^2$ and Fisher's exact test. Results: Of the 794 panoramic radiographs, 377 met the inclusion criteria for at least one side. The mental foramen was located just below the apex of the second premolar in 62.7% of the patients and between the first and second premolars in 30%. It was symmetrically located in 79%. No statistically significant differences were found between males and females in the position and symmetry of the mental foramen. Conclusion: The most common position for the mental foramen in this sample was in line with the second premolar.

• 전자공학회논문지B
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• 제30B권1호
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• pp.29-37
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• 1993

The purpose of this paper is to estimate the attitude and the position of SPOT satellite which are needed in producing DEM(Digital Elevation Model) using SPOT satellite image pairs. DEM extraction is consists of three parts. First part is the modeling of satellite position and atitude, second part is the matching of two images to find corresponding point of them and third part is to calculate the elevation of each point by using the result of the first and second part. For modeling inaccessible area, extended modeling algorithm which removes the GCP(Ground Control Point) most errorneous from the GCPs extracted from map iteratively is proposed According to the experiments using a collinearity equation, the second order polynomials are shown to the optimal for .omega.(pitch), and Zs parameters while the first order ones for .kappa.(yaw) .PHI.(roll), Xs, and Ys parameters. The input images used in this paper are 6000*6000 level 1A panchromatic digital SPOT images of Chungchong-do, Korea. With 30 GCPs, experiments on SPOT images show that the planimetric and altimetric RMS errors are 7.11m and 7.10m, respectively, for test points.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권10호
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• pp.473-478
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• 2001

Image processings using the two-dimensional wavelet transform (2DWT) have been a very active research area in recent years because the 2DWT possess many good properties. However, the discrete 2DWT can not be used for pattern recognition directly because it does not have the translation property. In this paper, we show why conventional discrete two-dimensional wavelet transforms cannot be used for pattern recognitions directly. Then, we propose a new method that makes it possible to use discrete 2DWT to pattern recognition without modification of standard pyramidal algorithms. The main idea of our method is to postprocess the wavelet transformed images using the second-order neural network. To justify the validity of the method, evaluations with test images were performed. The effectiveness of the method can be shown by the evaluation results.

• 한국간호교육학회지
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• 제28권2호
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• pp.167-178
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• 2022

Purpose: South Korea has expanded its accelerated second-degree Bachelor of Science in Nursing program to resolve its supply-demand imbalance in nursing, although how these students are adapting to and performing in college after admission remains unclear. Therefore, this study aimed to conduct an in-depth exploration of how Korean accelerated second-degree Bachelor of Science nursing students interact with society and adapt to college life for establishing further supportive educational policies and programs. Methods: Participants comprised 20 South Korean accelerated second-degree Bachelor of Science in Nursing students. The data were collected via online or offline in-depth interviews and analyzed using Strauss and Corbin's grounded theory and by applying a constant comparative method to achieve theoretical saturation. Results: The core category, derived using open, axial, and selective coding, was "process of the uncharted journey toward a new dream." The participants' college adaptation processes were found to involve three phases: trial and error, adjustment, and acceptance and integration. Conclusion: These findings can be used to develop, apply, test, and improve various support programs for accelerated second-degree Bachelor of Science in Nursing students and to advance the nursing profession by nurturing a workforce with diverse academic backgrounds and faster college life adaptation.

• 통합자연과학논문집
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• 제5권4호
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• pp.241-245
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• 2012

Categorical data collected based on complex sample design is not proper for the standard Pearson multinomial-based chi-squared test because the observations are not independent and identically distributed. This study investigates effects of bias of point estimator of population proportion and its variance estimator to the standard Pearson chi-squared test statistics when the sample is collected based on complex sampling scheme. This study examines the effect under two population homogeneity test. The standard Pearson test statistic can be partitioned into two parts; the first part is the weighted sum of ${\chi}^2_1$ with eigenvalues of design matrix as their weights, and the additional second part which is added due to the biases of the point estimator and its variance estimator. Our empirical analysis shows that even though the bias of point estimator is small, Pearson test statistic is very much inflated due to underestimate the variance of point estimator. In the connection of design-based variance estimator and its design matrix, the bigger the average of eigenvalues of design matrix is, the larger relative size of which the first component part to Pearson test statistic is taking.

• 대한정형외과스포츠의학회지
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• 제9권1호
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• pp.28-34
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• 2010

목적: 본 연구는 이중 다발 전방십자인대 재건술 후의 단기 임상결과와 이차적 관절경 소견을 알아보았다. 대상 및 방법: 이중 다발 전방십자인대 재건술 후에 최소 24개월 이상 추시가 가능하였던 49 예(환자)를 대상으로 하였다. 임상적 결과로 Lysholm 슬관절 점수, Tegner 활동 점수, 도수 및 기계적 전방 안정성 검사를 시행하였다. 15 예에서 스테플 제거와 함께 이차적 관절경 수술을 시행하여, 재건된 전방십자인대의 파열 유무와 이식건의 주관적인 긴장 정도 및 활액막 형성 정도를 검사하였다. 결과: Lysholm 슬관절 및 Tegner 활동 점수는 각각 술전 67.4, 2.0에서 최종 추시에 96.1, 6.1로 호전되었다 (p<0.01). Lachman 및 pivot-shift 검사에서 39예, 36예가 정상범위로 호전되었다. 스트레스 방사선 검사의 양측 차이 정도는 10.8 mm 에서 3.3 mm로 의미있게 호전되었다 (p<0.01). 이차적 관절경 소견상 모든 환자에서 전내측 다발이 정상 및 정상에 가까운 소견이 관찰되었으나, 8예 (53.3%) 에서 후외측 다발의 부분 및 완전 파열이 관찰되었다. 결론: 이중 다발 전방십자인대 재건술이 임상적으로 슬관절의 회전 및 전, 후방 안정성을 복원하는 효과적인 수술법이라도, 이차적 관절경 수술을 시행한 증례의 몇 예에서 후 외측 다발의 파열이 관찰되었다.

• Journal of applied mathematics & informatics
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• 제30권1_2호
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• pp.235-244
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• 2012

In this paper, we solve the three-dimensional biharmonic equation with Dirichlet boundary conditions of second kind using the full multigrid (FMG) algorithm. We derive a finite difference approximations for the biharmonic equation on a 18 point compact stencil. The unknown solution and its second derivatives are carried as unknowns at grid points. In the multigrid methods, we use a fourth order interpolation to producing a new intermediate unknown functions values on a finer grid, and the full weighting restriction operators to calculating the residuals at coarse grid points. A set of test problems gives excellent results.