• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11A
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• pp.878-891
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• 2011

We consider the throughput-maximization problem for both the up- and downlink in a wireless network with interference channels. For this purpose, we design an iterative and distributive uplink algorithm based on Lagrangian relaxation. Using the uplink power prices and network duality, we achieve throughput-maximization in the dual downlink that has a symmetric channel and an equal power budget compared to the uplink. The network duality we prove here is a generalized version of previous research [10], [11]. Computational tests show that the performance of the up- and downlink throughput for our algorithms is close to the optimal value for the channel orthogonality factor, ${\theta}{\in}$(0.5, 1]. On the other hand, when the channels are slightly orthogonal (${\theta}{\in}$(0, 0.5]), we observe some throughput degradation in the downlink. We have extended our analysis to the real downlink that has a nonsymmetric channel and an unequal power budget compared to the uplink. It is shown that the modified duality-based approach is thoroughly applied to the real downlink. Considering the complexity of the algorithms in [6] and [18], we conclude that these results are quite encouraging in terms of both performance and practical applicability of the generalized duality theorem.

• Kyungpook Mathematical Journal
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• v.45 no.2
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• pp.281-292
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• 2005

In this paper a nonlinear alternative of Leray-Schauder type is proved in a Banach algebra involving three operators and it is further applied to a functional nonlinear integral equation of mixed type $$x(t)=k(t,x({\mu}(t)))+[f(t,x({\theta}(t)))]\(q(t)+{\int}_0{^{\sigma}^{(t)}}v(t,s)g(s,x({\eta}\(s)))ds\)$$ for proving the existence results in Banach algebras under generalized Lipschitz and $Carath{\acute{e}}odory$ conditions.

• Journal of applied mathematics & informatics
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• v.10 no.1_2
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• pp.75-81
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• 2002

Lipschitz stability and Lipschitz ø$_{o}$ - equistability of the functional differential equation x'= B(x)f(t, x, $x_{t}$), $x_{to}$ =$\theta$$_{o}$ are discussed. Sufficient conditions are given using the comparison with the corresponding scalar equation.ion.n.

• Communications of the Korean Mathematical Society
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• v.27 no.4
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• pp.809-813
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• 2012

We introduce the notion of R($g$, $g^{\prime}$)-continuity on generalized topological spaces, which is a strong form of ($g$, $g^{\prime}$)-continuity. We investigate some properties and relationships among R($g$, $g^{\prime}$)-continuity, ($g$, $g^{\prime}$)-continuity and some strong forms of ($g$, $g^{\prime}$)-continuity.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.3
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• pp.267-279
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• 1998

A numerical study was made of flow behind a circular cylinder in a uniform flow, where the cylinder was rotationally oscillated in time. The temporal behavior of vortex formation was scrutinized over broad ranges of the two externally specified parameters, i.e., the dimensionless rotary oscillating frequency (.110.leq. $S_{f}$.leq..220) and the maximum angular amplitude of rotation (.theta.$_{max}$=15 deg., 30 deg. and 60 deg.). The Reynolds number (Re= $U_{{\inf}D}$.nu.) was fixed at Re=110. A fractional-step method was utilized to solve the Navier-Stokes equations with a generalized coordinate system. The main emphasis was placed on the initial vortex formations by varying $S_{f}$ and .theta.$_{max}$. Instantaneous streamlines and pressure distributions were displayed to show the vortex formation patterns. The vortex formation modes and relevant phase changes were characterized by measuring the lift coefficient ( $C_{L}$) and the time of negative maximum $C_{L}$( $t_{-C}$$_{Lmax}$) with variable forcing conditions.s.tions.s.s.s.

• Nuclear Engineering and Technology
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• v.18 no.1
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• pp.1-8
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• 1986

A magnetic quadrupole doublet was fabricated for use at the pre-target position of SNU 1.5MV Van de Graaff accelerator and then its optical characteristics were measured and analysed. The physical dimensions are: pole length 180mm, aperture radius 25mm, pole tip radius 28.75mm. Material for poles and return yokes is carbon steel KS-SM40C. Coils have 480 turns per one pole and air-cooling is adopted. Applying the d.c. current 2.99$\pm$0.03A to the lens, and using the Hall probe, magnetic field elements $B_{\theta}$ , $B_{\gamma}$, were measured at the selected Points along each coordinate direction r,$\theta$, z. From the area integration and orthogonal polynomial fitting for the measured data, the magnetic Field gradient G=566.3$\pm$2.1 gauss/cm at lens center, the effective length L=208.3$\pm$1.44mm along the lens axis have been obtained. The harmonic contents were determined up to 20-pole from the generalized least squares fitting. The results indicate that sextupole/quadrupole is below 1.4$\pm$0.9% and all the other multipoles are below 0.5% in the region within 18mm radius at the center of lens.

• Journal of the Korean Mathematical Society
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• v.47 no.3
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• pp.585-598
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• 2010

We deal with Matveev complexity of compact orientable 3-manifolds represented via Heegaard diagrams. This lead us to the definition of modified Heegaard complexity of Heegaard diagrams and of manifolds. We define a class of manifolds which are generalizations of Dunwoody manifolds, including cyclic branched coverings of two-bridge knots and links, torus knots, some pretzel knots, and some theta-graphs. Using modified Heegaard complexity, we obtain upper bounds for their Matveev complexity, which linearly depend on the order of the covering. Moreover, using homology arguments due to Matveev and Pervova we obtain lower bounds.

• Journal of Information Processing Systems
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• v.13 no.1
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• pp.174-183
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• 2017

In this paper, we propose a novel feature for recognizing handwritten Odia numerals. By using polygonal approximation, each numeral is segmented into segments of equal pixel counts where the centroid of the character is kept as the origin. Three primitive contour features namely, distance (l), angle (${\theta}$), and arc-tochord ratio (r), are extracted from these segments. These features are used in a neural classifier so that the numerals are recognized. Other existing features are also considered for being recognized in the neural classifier, in order to perform a comparative analysis. We carried out a simulation on a large data set and conducted a comparative analysis with other features with respect to recognition accuracy and time requirements. Furthermore, we also applied the feature to the numeral recognition of two other languages-Bangla and English. In general, we observed that our proposed contour features outperform other schemes.

• East Asian mathematical journal
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• v.24 no.1
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• pp.35-43
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• 2008

Let E be a uniformly convex Banach space and K be a nonempty closed convex subset of E. Let ${\{T_i\}}^N_{i=1}$ be N nonexpansive self-mappings of K with $F\;=\;{\cap}^N_{i=1}F(T_i)\;{\neq}\;{\theta}$ (here $F(T_i)$ denotes the set of fixed points of $T_i$). Suppose that one of the mappings in ${\{T_i\}}^N_{i=1}$ is semi-compact. Let $\{{\alpha}_n\}\;{\subset}\;[{\delta},\;1-{\delta}]$ for some ${\delta}\;{\in}\;(0,\;1)$ and $\{{\beta}_n\}\;{\subset}\;[\tau,\;1]$ for some ${\tau}\;{\in}\;(0,\;1]$. For arbitrary $x_0\;{\in}\;K$, let the sequence {$x_n$} be defined iteratively by $\{{x_n\;=\;{\alpha}_nx_{n-1}\;+\;(1-{\alpha}_n)T_ny_n,\;\;\;\;\;\;\;\;\; \atop {y_n\;=\;{\beta}nx_{n-1}\;+\;(1-{\beta}_n)T_nx_n},\;{\forall}_n{\geq}1,}$, where $T_n\;=\;T_{n(modN)}$. Then {$x_n$} convergence strongly to a common fixed point of the mappings family ${\{T_i\}}^N_{i=1}$. The result presented in this paper generalized and improve the corresponding results of Chidume and Shahzad [C. E. Chidume, N. Shahzad, Strong convergence of an implicit iteration process for a finite family of nonexpansive mappings, Nonlinear Anal. 62(2005), 1149-1156] even in the case of ${\beta}_n\;{\equiv}\;1$ or N=1 are also new.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.290-297
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• 1998

In this paper, we propose to a method to estimate the elasto-plastic buckling for single layer latticed domes. First, we assume that each member consists of the rigid zone and elastic spring at both end joint, the elastic element and three elasto-plastic spring to judge for yeilding the member. Next, the member which has most influence on buckling for structures is determined by a distributed pattern of the strain energy which is calculated through linear eigenvalue analysis. And then, normalized slenderness ratio of the element is derived considering the axial force at elastic buckling load. Later, we execute elasto-plastic nonlinear analysis that based on loading increasement method and displacement increasement method. From this results, we discusses the effect of the joint rigidity and the half open angle $\theta$$_{0}$ on the buckling strength of single layer lattice domes ; (1) how the joint rigidity contributes to the reduction of buckling loads, (2) how the reduction can be interrelated to compressive strength curves in terms of the generalized slenderness for the member most relevant to the overall buckling of domes.s.