• Journal of the Korean Mathematical Society
• /
• v.61 no.4
• /
• pp.683-692
• /
• 2024

Fake projective planes are smooth complex surfaces of general type with Betti numbers equal to that of the usual projective plane. Recent explicit constructions of fake projective planes embed them via their bicanonical embedding in ℙ⁹. In this paper, we study Keum's fake projective plane (a = 7, p = 2, {7}, D₃2₇) and use the equations of [1] to construct an embedding of fake projective plane in ℙ⁵. We also simplify the 84 cubic equations defining the fake projective plane in ℙ⁹.

• Journal of applied mathematics & informatics
• /
• v.17 no.1_2_3
• /
• pp.643-651
• /
• 2005

In the first part of this paper we investigate several statements concerning infinite maximal planar graphs which are equivalent in finite case. In the second one, for a given induced $\theta$-path (a finite induced path whose endvertices are adjacent to a vertex of infinite degree) in a 4-connected VAP-free maximal planar graph containing a vertex of infinite degree, a new $\theta$-path is constructed such that the resulting fan is tight.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 1998.10a
• /
• pp.255-261
• /
• 1998

The recent greenhouses are extremely light-weight structures and easily damaged by the strong winds due to the lack of uplift capacity of pile foundations. The uplift capacity of pile foundations are subject to the shape of the pile surface, diameter, weight, and embedded depths. etc. So, it is very important to figure out the most appropriate conditions on shape of the pile surface and it's embedding depths. to improve wind proof capability of pipe greenhouses. In this study, plane and corrugated pile surfaces were examined on their uplift capacity with 30 to 50 cm of embedding depths. The diameters of tested piles were 10 cm, 15 cm, and 20 cm, respectively. Compaction ratio of the tested soil was 80%. Each test run was repeated three times for the respective treatment. Obtained results are as follows; In all cases, as the diameter and the embedding depth were increased, the ultimate uplift capacity of the pile was also increased. And it was clear that the ultimate uplift capacity of corrugated pile was approximately two times as big as that of plain piles under same conditions.

• Proceedings of the IEEK Conference
• /
• 2003.11b
• /
• pp.157-160
• /
• 2003

Recently, several steganographic algorithms for two-color binary images have been proposed. In this paper, we propose a steganographic algorithm which embeds a secret message into bitmap images and palette-based images. To embed a message, the suggested algorithm divides a bitmap image into bit-plane images from LSB-plane to MSB-plane for each pixel, and considers each bit-plane image as a binary one. The algorithm splits each bit-plane image into m$\times$n blocks. and embeds a r-bit(r=[log$_2$(mn+1]-1) message into the block. And our schemes embed a message to every bit-plane from LSB to MSB to maximize the amount of embedded message and to minimize the degradation. The schemes change at most two pixels in each block. Therefore, the maximal color changes of the new algorithm are much smaller than other bit-plane embedding schemes' such as the substantial substitution schemes.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.13 no.6
• /
• pp.729-736
• /
• 2003

In this paper, we propose that the chaotic behavior analysis in the mobile robot of embedding some chaotic such as Chua`s equation, Arnold equation with obstacle. In order to analysis of chaotic behavior in the mobile robot, we apply not only qualitative analysis such as time-series, embedding phase plane, but also quantitative analysis such as Lyapunov exponent In the mobile robot with obstacle. We consider that there are two type of obstacle, one is fixed obstacle and the other is VDP obstacle which have an unstable limit cycle. In the VDP obstacles case, we only assume that all obstacles in the chaos trajectory surface in which robot workspace has an unstable limit cycle with Van der Pol equation.

• Bulletin of the Korean Mathematical Society
• /
• v.46 no.1
• /
• pp.171-182
• /
• 2009

In this paper, we consider the parameter space of the rational plane curves with uni-branched singularity. We show that such a parameter space is decomposable into irreducible components which are rational varieties. Rational parametrizations of the irreducible components are given in a constructive way, by a repeated use of Abhyankar-Moh Epimorphism Theorem. We compute an enumerative invariant of this parameter space, and include explicit computational examples to recover some classically-known invariants.

• Convergence Security Journal
• /
• v.10 no.2
• /
• pp.19-26
• /
• 2010

In this study, we try to make up for the vulnerability in steganography that it is easily revealed the hidden logo image in cover image by bit-plane extraction. For this, we apply some methods, the permutation which shift the scattered pieces of logo image to one side, bit-plane dispersion insertion method and pack-type compressor.

• Transactions on Electrical and Electronic Materials
• /
• v.16 no.5
• /
• pp.250-253
• /
• 2015

A novel implantable CPW fed Apollian shaped antenna embedded into human tissue is proposed for ISM band biomedical applications. The proposed antenna is made compatible for implantation by embedding it in an alumina ceramic substrate(ε_r=9.8 and thickness= 0.65 mm). The proposed antenna covers the ISM band of 2.45 GHz. The radiation parameters such as return loss, xy-plane, xz-plane, and yz-plane etc., are measured and analyzed using the agilent vector network analyzer. The proposed antenna has substantial advantages, including low profile, miniaturization ability, lower return loss, better impedance matching, and high gain over conventional implanted antennas.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.6
• /
• pp.1443-1447
• /
• 2012

In this paper, the characteristic of temperature variation was reviewed according to pattern variation. In order to degrade of diagnosis of power supply by using time series data for temperature measured by infrared camera it was transformed into 2 dimension phase plane using Takens embedding method. As a simulation results we cannot completely confirm the characteristic behaviors of nonlinear dynamics in phase plane. However these results has a certain patterns, it requires verification method through additional research in the future.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2003.09b
• /
• pp.110-113
• /
• 2003

In this paper, we propose that the chaotic behavior analysis in the mobile robot of embedding Arnold equation with obstacle. In order to analysis of chaotic behavior in the mobile robot, we apply not only qualitative analysis such as time-series, embedding phase plane, but also quantitative analysis such as Lyapunov exponent in the mobile robot with obstacle. In the obstacle, we only assume that all obstacles in the chaos trajectory surface in which robot workspace has an unstable limit cycle with Van der Pol equation.