• Nuclear Engineering and Technology
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• v.51 no.5
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• pp.1279-1288
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• 2019

The vortex-type fluidic diode (FD) is a key safety component for inherent safety in various advanced reactors such as the sodium fast reactor (SFR) and the molten salt reactor (MSR). In this study, topology optimization is conducted to optimize the design of the vortex-type fluidic diode. The optimization domain is simplified to 2-dimensional geometry for a tangential port and chamber. As a result, a design with a circular chamber and a restrictor at the tangential port is obtained. To verify the new design, experimental study and computational fluid dynamics (CFD) analysis were conducted for inlet Reynolds numbers between 2000 and 6000. However, the results show that the performance of the new design is no better than the original reference design. To analyze the cause of this result, detailed analysis is performed on the velocity and pressure field using flow visualization experiments and 3-D CFD analysis. The results show that the discrepancy between the optimization results in 2-D and the experimental results in 3-D originated from exclusion of an important pressure loss contributor in the optimization process. This study also concludes that the junction design of the axial port and chamber offers potential for improvement of fluidic diode performance.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.153.5-153
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• 2001

This paper presents a simple modeling system that constructs 3D models from an indoor cylindrical environment map using all of the available geometry of the interior structure such as vertical and horizontal lines and parallel and perpendicular planes. The indoor scene abstract model is created through this system and the navigation through the process of 3D reconstruction. This system first automatically detects the vanishing points in a cylindrical environment map from parallel lines and planes, and determines the indoor scene topology previously defined using this information. The determined topology enables he user intervention UI simply construct a 3D model by using the photogrammetry. The modeling system can be ...

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.10a
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• pp.13-18
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• 2004

In this study, a new method is proposed generating 3D wire-frames of building using the lowest level topology, points, which are input by human operators. Through the procedure, it is possible to make prediction occlusion points and generate the topology automatically among points, lines, surfaces from buildings. In order to adjust the error of initial values which are input manually, the least squares adjustment for model-image fitting is carried out using the edge information of aerial imagery. And also, model fitting procedure is done making all surfaces plane of buildings by the least squares adjustment. As a result of those procedure, 3D building models are refined similar to real figures of buildings.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2138-2142
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• 2013

Two new 3D coordination complexes [Cd(3-bpcd)(pht)] (1) and [Zn(3-bpcd)(pht)] (2) [3-bpcd = N,N'-bis(pyridin-3-yl)cyclohexane-1,4-dicarboxamide, $H_2pht$ = phthalic acid] have been hydrothermally synthesized. X-ray diffraction analysis reveals that the complexes 1 and 2 represent a 4-connected diamondoid topology with a 3-fold interpenetrating feature. Moreover, the fluorescent properties of complexes 1 and 2 are studied.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.301-304
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• 2014

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.1
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• pp.29-34
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• 2015

This paper reports a couple of key circuit blocks developed for heterodyne receiver front-ends operating near 140 GHz based on SiGe HBT technology. Firstly, a 123-GHz oscillator was developed based on Colpitts topology, which showed -5 dBm output power and phase noise of -107.34 dBc/Hz at 10 MHz. DC power dissipation was 25.6 mW. Secondly, a 135 GHz mixer was developed based on a modified Gilbert Cell topology, which exhibited a peak conversion gain of 3.6 dB at 1 GHz IF at fixed LO frequency of 134 GHz. DC power dissipation was 3 mW, which mostly comes from the buffer.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.157-162
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• 2007

A new level set based topology optimization employing inner-front creation algorithm is presented. In the conventional level set based topology optimization, the optimum topology strongly depends on the initial level set distribution due to the incapability of inner-front creation during optimization process. In the present work, in this regard, an inner-front creation algorithm is proposed. in which the sizes. shapes. positions, and number of new inner-fronts during the optimization process can be globally and consistently identified by considering both the value of a given criterion for inner-front creation and the occupied volume (area) of material domain. To facilitate the inner-front creation process, the inner-front creation map which corresponds to the discrete valued criterion of inner-front creation is applied to the level set function. In order to regularize the design domain during the optimization process, the edge smoothing is carried out by solving the edge smoothing partial differential equation (PDE). Updating the level set function during the optimization process, in the present work, the least-squares finite element method (LSFEM) is employed. As demonstrative examples for the flexibility and usefulness of the proposed method. the level set based topology optimization considering lightweight design of 3D shell structure is carried out.

• The Pure and Applied Mathematics
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• v.30 no.3
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• pp.237-248
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• 2023

The aim of this paper is to study the concept of s-topological d-algebras which is a d-algebra supplied with a certain type of topology that makes the binary operation defined on it d-topologically continuous. This concept is a generalization of the concept of topological d-algebra. We obtain several properties of s-topological d-algebras.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.6
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• pp.1312-1317
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• 2012

ZSphere of ZBrush can be added to the canvas, and most of all, added to the existing ZSphere as mobile geometrical objects. For example, arms can be produced out of the globoid in the progress of an intermediate step. characters with multiple limbs can be produced easily in this way. With Zsphere, several Child Spheres can be produced out of single Sphere, then these can be parents spheres, and can connect other Child Spheres. In this paper, by making each form through these processes, 3D characters were modeled to shape easily and rapidly. Since 3D objects can be added, rotated, and moved, they can interact smoothly with Z-depth of campus. To place these objects on the screen, paint, build fixed perspective image, smerge pixols and transform 3D objects, diverse transforming tools and sculpturing tools were used. The characters were designed in the way that first, the finished 3D characters were transformed into poly, then each side was restructured rapidly with Topology.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.101-103
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• 2007

혈관 구조는 사람의 가장 복잡한 구조 중 하나이다. 혈관 분석에는 Morphology and Topology 가 있다. 우리는 목표는 위 분석 기법과는 달리 3D 영상 재구성이다. 본 논문은 Raw CT data 을 세그먼트하고 Skeleton line 을 인용하여 복잡한 트리 형태의 혈관 3D 재구성을 하였다.