• 한국가시화정보학회:학술대회논문집
• /
• 2002.11a
• /
• pp.11-14
• /
• 2002

A new high-definition stereoscopic PTV was constructed using two CCD cameras, stereoscopic photogrammetry based on a 30-PTV principle. The arrangement of the two cameras was based on angular position. The calibration of cameras and the pair-matching of the three-dimensional velocity vectors were based on Genetic Algorithm based 30-PTV technique. The constructed Stereoscopic PTV technique was tested on the standard images of the Impinging jet proposed by VSJ. The results on the turbulent properties of the jet obtained by the constructed system showed a good agreement with the original LES data.

• Journal of KIBIM
• /
• v.9 no.2
• /
• pp.21-28
• /
• 2019

Recently, many scan projects are gradually increasing for maintenance, construction. The scan data contains useful data, which can be generated in the target application from the facility, space. However, modeling the scan data required for the application requires a lot of cost. In example, the converting 3D point cloud obtained from scan data into 3D object is a time-consuming task, and the modeling task is still very manual. This research proposes Scan-to-Geometry Mapping Rule Definition (S2G-MD) which maps point cloud data to geometry for irregular building plane objects. The S2G-MD considers user use case variability. The method to define rules for mapping scan to geometry is proposed. This research supports the reverse engineering semi-automatic process for the building planar geometry from the user perspective.

• Nuclear Engineering and Technology
• /
• v.55 no.12
• /
• pp.4307-4316
• /
• 2023

In this paper, modal effective mass for asymmetric fluid-structure interaction system is defined and equations for its calculation is derived. To establish consistency, modal effective mass in symmetric structure only system is briefly reviewed, followed by a definition of the modal effective mass in asymmetric system. The equations for calculating modal effective mass in asymmetric system are derived by utilizing the properties of left and right eigenvectors. To simplify the equations, the assumption is made that the mass matrix is only affected by the fluid. The simplified equation is then compared to the equation already used in ANSYS. Finally, the validity of the modal effective mass definition and derivation in this paper is demonstrated through a simple example.

• Clinical Endoscopy
• /
• v.55 no.6
• /
• pp.726-735
• /
• 2022

Inflammatory bowel disease (IBD) has a global presence with rapidly increasing incidence and prevalence. Patients with IBD including those with ulcerative colitis and Crohn's disease have a higher risk of developing colorectal cancer (CRC) compared to the general population. Risk factors for CRC in patients with IBD include long disease duration, extensive colitis, primary sclerosing cholangitis, family history of CRC, stricture, and prior dysplasia. Surveillance colonoscopy for CRC in patients with IBD should be tailored to individualized risk factors and requires careful monitoring every year to every five years. The current surveillance techniques are based on several guidelines. Chromoendoscopy with targeted biopsy is being recommended increasingly, and high-definition colonoscopy is gradually replacing standard-definition colonoscopy. However, it remains unclear whether chromoendoscopy, virtual chromoendoscopy, or white-light endoscopy has better efficiency when a high-definition scope is used. With the development of new endoscopic instruments and techniques, the paradigm of surveillance strategy has gradually changed. In this review, we discuss cutting-edge surveillance colonoscopy in patients with IBD including a review of literature.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1991.11a
• /
• pp.105-109
• /
• 1991

A computer aided flatness calibration system has been developed. Rectangular grids based measurement procedure is proposed with closing error technique. giving advantages over conventional diagonal measurement procedures (‘Union Jack’). A new analysis technique has been developed for flatness evaluation called ‘ETT(Enclose Tilt technique)’, enabling minimum separation definition which is acknowledged as standard term for flatness definition. Practical assessment shows the performance of the developed system.

• Bulletin of the Korean Mathematical Society
• /
• v.54 no.6
• /
• pp.2053-2063
• /
• 2017

In this paper we prove a condition under which a hyperbolic starshaped set has a center of hyperbolic symmetry. We also give the definition of isometric diameters for a hyperbolic convex set, which behave similar to affine diameters for Euclidean convex sets. Using this concept, we give a definition of constant hyperbolic width and we prove that the only hyperbolic sets with constant hyperbolic width and with a hyperbolic center of symmetry are hyperbolic discs.

• Communications of the Korean Mathematical Society
• /
• v.22 no.1
• /
• pp.123-135
• /
• 2007

This paper has two objectives. The first objective is to study slant submanifolds of quaternion Kaehler manifolds. We give characterization theorems and examples of slant submanifolds. For the second objective, we introduce the notion of semi-slant submanifolds which are different from the definition of N. Papaghiuc [15]. We obtain characterization theorems, examples of semi-slant sub manifolds and investigate the geometry of leaves of distributions which are involved in the definition of semi-slant submanifolds.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1997.10a
• /
• pp.57-59
• /
• 1997

The concept of fuzzy sets was introduced by Zad도 in his highly influential paper [5]. Using this concept, Chang [1] introduced a notion of fuzzy topological spaces which formally is the same one as for ordinary topological spaces. Observing that with Chang's definition constant maps between fuzzy topological spaces are not necessarily continuous, Lowen [2] gave an alternative and more natural definition for a fuzzy topological spaces and characterized the fuzzy compact spaces by means of prefilters in [4]. In this paper we give new characterizations of fuzzy compact spaces introduced in [2]. These results explain more clearly fuzzy compactness in fuzzy topological spaces.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.06a
• /
• pp.509-510
• /
• 2007

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2006.11a
• /
• pp.149-152
• /
• 2006

By generalizing the definition of B. S. Zhong, we introduce the concept of fuzzy weakly ${\gamma}-semicontinuous$ maps in fuzzy topology of Chattopadhyay. Then the concept introduced by B. S. Zhong become special case of our definition. Also, we show that fuzzy weakly ${\gamma}-semicontinuity$ and fuzzy weakly ${\gamma}-continuity$ are independent notions.