• Bulletin of the Korean Mathematical Society
• /
• v.59 no.5
• /
• pp.1131-1144
• /
• 2022

In this paper, we establish several basic formulas among the double-integral transforms, the double-convolution products, and the inverse double-integral transforms of cylinder functionals on abstract Wiener space. We then discuss possible relationships involving the double-integral transform.

• Journal of the Korean Data and Information Science Society
• /
• v.20 no.2
• /
• pp.459-465
• /
• 2009

For an inverse double Weibull distribution which is symmetric about zero, we obtain distribution and moment of ratio of independent inverse double Weibull variables, and also obtain the cumulative distribution function and moment of a skew-symmetric inverse double Weibull distribution. And we introduce a skew-symmetric inverse double Weibull generated by a double Weibull distribution.

• Journal of the Chungcheong Mathematical Society
• /
• v.27 no.4
• /
• pp.603-614
• /
• 2014

We introduce the concepts of ($\mathcal{T}^{{\mu}{\gamma}}$, $\mathcal{U}^{{\mu}{\gamma}}$)-double (r, s) (u, v)-semiclosures and ($\mathcal{T}^{{\mu}{\gamma}}$, $\mathcal{U}^{{\mu}{\gamma}}$)-double (r, s)(u, v)-semiinteriors. Using the notions, we investigate some of characteristic properties of double pairwise (r, s)(u, v)-semicontinuous, double pairwise (r, s)(u, v)-semiopen and double pairwise (r, s)(u, v)-semiclosed mappings.

• Journal of applied mathematics & informatics
• /
• v.39 no.1_2
• /
• pp.155-163
• /
• 2021

For a connected graph G of order n, a set S of vertices is called a double geodetic set of G if for each pair of vertices x, y in G there exist vertices u, v ∈ S such that x, y ∈ I[u, v]. The double geodetic number dg(G) is the minimum cardinality of a double geodetic set. Any double godetic set of cardinality dg(G) is called a dg-set of G. A connected double geodetic set of G is a double geodetic set S such that the subgraph G[S] induced by S is connected. The minimum cardinality of a connected double geodetic set of G is the connected double geodetic number of G and is denoted by dgc(G). A connected double geodetic set of cardinality dgc(G) is called a dgc-set of G. Connected graphs of order n with connected double geodetic number 2 or n are characterized. For integers n, a and b with 2 ≤ a < b ≤ n, there exists a connected graph G of order n such that dg(G) = a and dgc(G) = b. It is shown that for positive integers r, d and k ≥ 5 with r < d ≤ 2r and k - d - 3 ≥ 0, there exists a connected graph G of radius r, diameter d and connected double geodetic number k.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.7 no.4
• /
• pp.249-255
• /
• 2007

In this paper, we introduce the concept of double fuzzy preproximity spaces as a generalization of a fuzzy preproximity spaces and investigate some of their properties. Also we study the relationships between double fuzzy preproximity spaces, double fuzzy topological spaces and double fuzzy closure spaces. In addition to this was the introduction of the concept of double fuzzy neighborhood system and has been studying the connection with double fuzzy preproximity, which resulted in the definition of the concept double fuzzy preproximal neighborhood.

• Journal of the Chungcheong Mathematical Society
• /
• v.26 no.4
• /
• pp.691-702
• /
• 2013

We introduce the concepts of double bitopological spaces as a generalization of intuitionistic fuzzy topological spaces in $\check{S}$ostak's sense and Kandil's fuzzy bitopological spaces. Also we introduce the concept of (${\tau}^{{\mu}{\gamma}}$, $U^{{\mu}{\gamma}}$)-double (r, s)(u, v)-semiopen sets and double pairwise (r, s)(u, v)-semicontinuous mappings in double bitopological spaces and investigate some of their characteristic properties.

• Journal of the Chungcheong Mathematical Society
• /
• v.29 no.1
• /
• pp.13-22
• /
• 2016

We introduce the concepts of double (r, s)(u, v)-preopen sets, double (r, s)(u, v)-preclosed sets and double pairwise (r, s)(u, v)-precontinuous mappings in double bitopological spaces and investigate some of their characteristic properties.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.3
• /
• pp.440-447
• /
• 2018

Double parking is very common in a parking lot where there is not sufficient parking space. When we double-park a car, we leave transmission gear in neutral position and release the emergency brake so that the double-parked car can be moved just by pushing it. However, moving a double-parked car by pushing is very hard and dangerous especially for the old and the weak. So, we propose an omni-directional mobile robot for moving a double-parked car easily and safely. The developed omni-directional mobile robot moves a double-parked car by rotating a wheel of a double-parked car. It has two specially designed rollers to rotate a wheel of a double-parked car and is designed so that the height of the robot is very low to be able to enter beneath a double-parked car. It can move a double-parked car safely by detecting obstacles in the way with five ultrasonic sensors. We verified by several experiments that the developed omni-directional mobile robot can be used to move a double-parked car easily and safely.

• Archives of Plastic Surgery
• /
• v.50 no.2
• /
• pp.142-147
• /
• 2023

Some of Asian eyelids have double fold and some do not. Many people tend to prefer double eyelid in aesthetic and functional reasons. Since the mechanism of double eyelid is bonding the eyelid skin to the eye-opening tissue, the principle of double eyelid surgery is also connecting the eyelid skin to levator component. Double eyelids are differentiated by their shape according to the height and curvature. The double eyelid surgery procedure is divided into incision method and nonincision method. And the incision method is subdivided into double fold line design, skin and oculi muscle incision or excision, pretarsal or preaponeurotic soft tissue excision, fixation of posterior lamella to anterior lamella, and skin suture. The nonincision method is to connect the posterior lamella and the anterior lamella as a thread only without an incision. A successful double eyelid surgery creates a fold well-balanced in height, curvature, and depth of the fold based on patient's preference. In this article, the author's own methods of performing surgery are described, with a step-by-step guide and surgical tips.

• Journal of Fisheries and Marine Sciences Education
• /
• v.27 no.6
• /
• pp.1727-1733
• /
• 2015

In the present study, the heat transfer performance of dimpled double-pipe heat exchangers for fuel cells that are utilized as cooling systems of fuel cells was studied. In addition, to comparatively analyze the heat transfer performance of dimpled double-pipe heat exchanger for fuel cells, plain double-pipe heat exchangers were also studied. Experimental results were derived on changes in the Reynolds numbers of the cooling water flowing in dimpled and plain double-pipe heat exchangers and changes in the heat flux of the air. Thereafter, to verify the reliability of the experimental results, the theoretical overall heat transfer coefficients and the experimental overall heat transfer coefficients were comparatively analyzed and the following results were derived. The heat transfer rate lost by the hot air and that of the heat transfer rate obtained by the cooling water were well balanced. The experiments of plain double-pipe heat exchangers and dimpled double-pipe heat exchangers were conducted under normal conditions and the theoretical overall heat transfer coefficient and the experimental overall heat transfer coefficient coincided well with each other. In both plain double-pipe heat exchangers and dimpled double-pipe heat exchangers, heat transfer rates increased as the cooling water flow velocity increased. Under the same experimental conditions, the heat transfer performance of dimpled double-pipe heat exchangers was shown to be higher by 1.2 times than that of plain double-pipe heat exchangers.