• Proceedings of the KSMRM Conference
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• 2002.11a
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• pp.104-104
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• 2002

목적： SAAV sequence를 이용하여 동시에 획득한 동맥과 정맥의 두 MRA 영상을 Color Mapping으로 동맥과 정맥을 구분하여 한 영상에 나타냄으로써 AVM 이나 DAVF 등과 같은 혈관질환의 임상적 진단 및 치료에 도움을 주고자 하였다. 대상 및 방법： 일반적으로 MRA 영상은 사전 포화방법(presaturation)을 이용한 2D TOF 기법을 통하여 동맥과 정맥을 구분하여 영상을 획득한다. 이러한 일반적인 사전포화방법을 응용한 SAAV 기법은 일정영역을 미리 포화(saturation)시킨 후 포화영역의 위, 아래의 영역을 한번에 영상화하여 동맥과 정맥의 구분된 영상을 한번에 획득할 수 있다. 마산 삼성병원의 0.3T MRI system(Megfinder, AILab. Korea)에서 SAAV sequence를 이용하여 정상적인 피험자로부터 목 부위의 동맥과 정맥 혈관영상을 동시에 얻었다. 이들의 각 2D 영상을 Color Mapping으로 조합한 후 Maximum Intensity Projection(MIP) 기법을 통해 3D Artery-Vein Color Mapping(AVCM) MRA 영상으로 재구성하였다. 3명의 피험자에 대한 SAAV MRA data를 256$\times$256$\times$64(resolution： 0.89$\times$0.89$\times$2㎣)로 획득하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.295-298
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• 2006

본 논문에서는 극 좌표계에서의 벡터 표현 방식을 이용한 per-pixel displacement mapping 방법을 제시한다. per-pixel displacement mapping은 triangle mesh의 처리 방식에 상관없이 변위매핑을 수행할 수 있도록 한 것으로, 2차원 screen space로 projection 된 triangle의 각 pixel의 위치를 객체 표면 정보에 따라 displacement 해주는 방법이다. 이는 기 검증된 범프매칭 하드웨어에 약간의 하드웨어를 추가함으로써 변위매핑을 수행할 수 있도록 한 효과적인 구조이다. 제안 방식에 의해 생성된 영상과 기존 방식에 의해 생성된 영상을 비교해본 결과, 시각적으로 거의 차이가 없음을 알 수 있다.

• Nonlinear Functional Analysis and Applications
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• v.26 no.4
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• pp.839-853
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• 2021

Let 𝕽ⁿ be an Euclidean space and g : 𝕽ⁿ → 𝕽ⁿ be a monotone and continuous mapping. Suppose the convex constrained nonlinear monotone equation problem x ∈ 𝕮 s.t g(x) = 0 has a solution. In this paper, we construct an inertial-type algorithm based on the three-term derivative-free projection method (TTMDY) for convex constrained monotone nonlinear equations. Under some standard assumptions, we establish its global convergence to a solution of the convex constrained nonlinear monotone equation. Furthermore, the proposed algorithm converges much faster than the existing non-inertial algorithm (TTMDY) for convex constrained monotone equations.

• Nonlinear Functional Analysis and Applications
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• v.27 no.3
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• pp.553-568
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• 2022

In this paper, we introduce and study two different iterative hybrid projection algorithms for solving a fixed point problem of nonexpansive mappings. The first algorithm is generated by the combination of the inertial method and the hybrid projection method. On the other hand, the second algorithm is constructed by the convex combination of three updated vectors and the hybrid projection method. The strong convergence of the two proposed algorithms are proved under very mild assumptions on the scalar control. For illustrating the advantages of these two newly invented algorithms, we created some numerical results to compare various numerical performances of our algorithms with the algorithm proposed by Dong and Lu [11].

• Kyungpook Mathematical Journal
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• v.64 no.1
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• pp.69-94
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• 2024

In this paper, we introduce an inertial self-adaptive projection method using Bregman distance techniques for solving pseudomonotone equilibrium problems in reflexive Banach spaces. The algorithm requires only one projection onto the feasible set without any Lipschitz-like condition on the bifunction. Using this method, a strong convergence theorem is proved under some mild conditions. Furthermore, we include numerical experiments to illustrate the behaviour of the new algorithm with respect to the Bregman function and other algorithms in the literature.

• Journal of Digital Contents Society
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• v.19 no.7
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• pp.1341-1348
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• 2018

In this study, we propose a method for applying the image content to the exhibition space using projection mapping techniques. In a typical exhibition space, the artist exhibits works and displays them unilaterally and by using walls defined as screens. However, the new form of exhibition is not one-sided and changes in the way space is free from constraint. The purpose of the exhibition space is to use walls or various installations, which are elements of the exhibition space, as a key part of the exhibition rather than as a material for the spatial compartment. This type of display is a display element of space and you can enjoy the fun and excitement of the exhibition about the new environment. Various imaging techniques are required to construct an exhibition of images and spaces, among which edge blocking is not formed.

• Communications of the Korean Mathematical Society
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• v.26 no.1
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• pp.125-133
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• 2011

A new kind of structure is introduced in an even dimensional differentiable Riemannian manifold and some basic properties of this structure is discussed. Also the existence of such structure is shown with an example.

• Journal of Digital Contents Society
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• v.18 no.1
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• pp.123-132
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• 2017

The physical display technology is the ultimate display technology that human beings aspire, and the world makes use of laser, plasma and reflector plate. Besides, technology development of binocular stereoscopic display has been actively progressed, but there is a limitation to the intact physical representation such as influence of optical ambient light and brightness. In this paper, the display technology using physical deformation different from the existing optical display is approached as a cultural and emotional perspective. The purpose of this paper is to develop the multivariate display technology that can create 3D realistic stereoscopic images through projecting dynamic images on physically diversified screen by overcoming the limitations of 2D planar digital signage and study how to apply them to video, exhibition and performance.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.3 no.2
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• pp.1-10
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• 1985

Moire technique is generally divided into shadow Moire Technique and Projection Moire Technique. In this paper, determinating the direction of reference planes for this system, by comparing the results of this system with those of general terrestrial photogrammetry, is an objective of this paper. For the objective, control surveying is done and the results of control surveying are compared with those of moire photograph. In this technique, it is found that though the positions of a projector and a reference grid are not moved, a desired moire contour whose the reference plane is different respectively is easily obtained by changing the pitches of a master grid and a reference grid on an object. Also it is found that when the pitches of the two grids on an object are equal, a moire contour which has the reference plane parallel to the object can be obtained.

• Bulletin of the Korean Mathematical Society
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• v.58 no.6
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• pp.1355-1375
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• 2021

The n-dimensional generalized Hartogs triangles ℍⁿ_𝐩 with n ≥ 2 and 𝐩 := (p₁, …, p_n) ∈ (ℝ⁺)ⁿ are the domains defined by ℍⁿ_𝐩 := {z = (z₁, …, z_n) ∈ ℂⁿ : |z₁|^p₁ < ⋯ < |z_n|^p_n < 1}. In this paper, we study the L^p Sobolev mapping properties for the Bergman projections on the n-dimensional generalized Hartogs triangles ℍⁿ_𝐩, which can be viewed as a continuation of the work by S. Zhang in [25] and a higher-dimensional generalization of the work by L. D. Edholm and J. D. McNeal in [16].