• 대한수학회보
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• 제57권5호
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• pp.1241-1249
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• 2020

Let Ω be a domain in ℂⁿ. Suppose that ∂Ω is smooth pseudoconvex of D'Angelo finite type near a boundary point ξ₀ ∈ ∂Ω and the Levi form has corank at most 1 at ξ₀. Our goal is to show that if the squeezing function s_Ω(𝜂_j) tends to 1 or the Fridman invariant h_Ω(𝜂_j) tends to 0 for some sequence {𝜂_j} ⊂ Ω converging to ξ₀, then this point must be strongly pseudoconvex.

• 한국정밀공학회지
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• 제24권11호
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• pp.144-153
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• 2007

In order to generate the input data for rapid prototyping, a new approach which is based on the implicit surface interpolation method is presented. In the method a surface is reconstructed by creating smooth implicit surface from unorganized cloud of points through which the surface should pass. In the method an implicit surface is defined by the adaptive local shape functions including quadratic polynomial function, cubic polynomial function and RBF(Radial Basis Function). By the reconstruction of a surface, various types of error in raw STL file including degenerated triangles, undesirable holes with complex shapes and overlaps between triangles can be eliminated automatically. In order to get the slicing data for rapid prototyping an efficient intersection algorithm between implicit surface and plane is developed. For the direct usage for rapid prototyping, a robust transformation algorithm for the generation of complete STL data of solid type is also suggested.

• Kyungpook Mathematical Journal
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• 제55권4호
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• pp.753-771
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• 2015

A complete invariant defined for (closed connected orientable) 3-manifolds is an invariant defined for the 3-manifolds such that any two 3-manifolds with the same invariant are homeomorphic. Further, if the 3-manifold itself can be reconstructed from the data of the complete invariant, then it is called a characteristic invariant defined for the 3-manifolds. In a previous work, a characteristic lattice point invariant defined for the 3-manifolds was constructed by using an embedding of the prime links into the set of lattice points. In this paper, a characteristic rational invariant defined for the 3-manifolds called the characteristic genus defined for the 3-manifolds is constructed by using an embedding of a set of lattice points called the PDelta set into the set of rational numbers. The characteristic genus defined for the 3-manifolds is also compared with the Heegaard genus, the bridge genus and the braid genus defined for the 3-manifolds. By using this characteristic rational invariant defined for the 3-manifolds, a smooth real function with the definition interval (-1, 1) called the characteristic genus function is constructed as a characteristic invariant defined for the 3-manifolds.

• International Journal of Internet, Broadcasting and Communication
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• 제9권4호
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• pp.19-24
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• 2017

In this paper, we propose an automatic segmentation method of left and right heart in computed tomography angiography (CTA) using separating energy function. First, we smooth the images by applying anisotropic diffusion filter to remove noise. Then, the volume of interest (VOI) is detected by using k-means clustering. Finally, we extract the left and right heart with separating energy function which we proposed to split the heart. We tested our method in ten CT images and they were obtained from a different patient. For the evaluation of the computational performance of the proposed method, we measured the total processing time. The average of total processing time, from first step to third step, was $14.39{\pm}1.17s$. We expect for our method to be used in cardiac diagnosis for cardiologist.

• 한국컴퓨터그래픽스학회논문지
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• 제6권4호
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• pp.15-22
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• 2000

영상기반 모델링 및 렌더링의 주된 흐름중의 하나는 plenoptic function을 어떻게 구현할 것인가에 집중되고 있다. 본 논문은 임의의 위치에 배치된 파노라마 군을 이용하여 plenoptic function을 구현하는 새로운 기법을 제안한다. 이 기법은 우선 간단한 컴퓨터 비전 기술을 사용하여 주변 환경에 대한 개괄적인 깊이 정보를 추출한 뒤, 이를 이용하여 파노라마 영상 데이터를 보정/보간하여 새로운 시점에서의 렌더링을 수행한다. 본 기법을 사용한 결과 실시간에 부드러운 네비게이션을 구현할 수 있었다.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.17-21
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• 2022

A variety of techniques have been proposed in the literature for depth improvement in depth from focus method. Unfortunately, these techniques over-smooth the depth maps over the regions of depth discontinuities. In this paper, we propose a robust technique for improving the depth map by employing a nonconvex smoothness function that preserves the depth edges. In addition, the proposed technique exploits the mutual structures between the depth map and a guidance map. This guidance map is designed by taking the mean of image intensities in the image sequence. The depth map is updated iteratively till the nonconvex objective function converges. Experiments performed on real complex image sequences revealed the effectiveness of the proposed technique.

• 기술혁신연구
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• 제5권1호
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• pp.150-180
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• 1997

This article introduces the five functions of the national innovation system(NIS). As one of social systems in the national level, the five generic functions of open system - production, boundary spanning, maintenance, adaptation, management functions - are applied to the NIS. The production function is the primary process, which produces innovative products and services of the NIS. The boundary spanning function is the function of procuring input and disposing the innovation output or aiding in these processes. Experienced R&D human resources, R&D funds, technology etc. are some of the components of the input of the NIS. The maintenance function is responsible for maintaining smooth operation and upkeeping the system in terms of various conditions. The adaptation function is to help the system change and adapt, and scan the environment for problems, opportunites, and technological developments. It has outward orientation, from the long-term view for the survival of the system. The management function carries out planning and control of the overall activities for the other four functions in order to effectiving run the system as a whole. Finally, this article discusses implications of the diagnosis of the national innovation system and the decision making process of S&T policy.

• 한국인구학
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• 제18권2호
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• pp.115-168
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• 1995

한국경제의 장기적 발전은 총투자의 지속적 증가와 이를 가능케 해줄 국민저축의 착실한 증가에 크게 의존한다고 보겠다. 이러한 국민저축 중에서도 가계저축은 우리나라의 투자재원 조달에 가장 중요한 역할을 담당할 것으로 기대되고 있다. 본고는 가계저축의 결정요인을 찾아내기 위하여 우리나라 가계소비율의 결정요인을 살펴본 다음에 이를 이용하여 간접적으로 가계저축의 결정요인을 원용하였다. 이와 같이 가계소비율의 추정을 통하여 가계저축율을 추정하고자 한 이유는 일반적으로 소비함수는 안정적인 성향을 가진 반면 저축함수는 불안정적인 성향이 강하기 때문이다. 가계소비율 추정을 위해서는 우리나라의 도시가계조사 및 농가경제 조사자료를 기초자료로 이용하였는 바, 가계소비율에 대한 회귀분석의 결과를 요약하면, 첫째로 가계소득의 증가와 취업가구원수의 증가는 가계소비율을 낮추는 방향으로 작용하고 있는 반면, 둘째로 가구주의 연령, 교육수준, 가구원수의 증가는 가계소비율을 저하시키는 경향이 있는 것으로 나타났다. 2000년대의 우리나라는 소득의 괄목할 만한 증가, 여성의 노동시장 참가율 제고로 인한 취업가구원수의 증가 및 핵가족화의 영향으로 인한 평균 가구원수의 감소로 가계소비율의 저하가 예상되는 반면에, 인구의 노령화에 기인한 가구주의 평균연령의 상승, 교육수준의 향상에 따른 가계소비율의 상승이 예상되지만, 총체적으로는 가계소비율의 감소를 통한 가계 저축율의 착실한 증가가 있을 것으로 예측되므로 한국경제의 장기적 발전을 위한 투자재원의 조달에는 큰 어려움이 없을 것으로 전망된다.

• Journal of the Korean Data and Information Science Society
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• 제5권2호
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• pp.95-106
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• 1994

A proposed test statistic is obtained by multiplying constant weights by the Neumann smooth type statistic discussed by Eubank and Hart(1993) in order to observe the effect of weight. It has very good results of power studies. Another advantage of this test is that it simultaneously provides an important diagnostic tools that can be used in many cases to determine how the model should be adjusted.

• Journal of applied mathematics & informatics
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• 제27권1_2호
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• pp.69-78
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• 2009

The accuracy of wavelet approximation at resolution h = $2^{-k}$ to a smooth function f is limited by O($h^M$), where M is the number of vanishing moments of the mother wavelet ${\psi}$; that is, the approximation order of wavelet approximation is M - 1. High accuracy points of wavelet approximation are of interest in some applications such as signal processing and numerical approximation. In this paper, we prove the scaling and translating properties of high accuracy points of wavelet approximation. To illustrate the results in this paper, we also present two examples of high accuracy points of wavelet approximation.