• Journal of applied mathematics & informatics
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• v.32 no.1_2
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• pp.153-159
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• 2014

In this paper, we introduce a pair of higher-order symmetric dual models/problems. Weak, strong and converse duality theorems for this pair are established under the assumption of higher-order invexity. Moreover, self duality theorem is also discussed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.2
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• pp.140-144
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• 2004

The selectable dual band LNA usually uses common source transistor pair each input of which is selectively driven at a different frequency in a series resonant form. This paper analyzes the degradation in noise figures of the MOSFET common source pair with series resonance when it is driven concurrently at both inputs with different frequencies as a concurrent dual band LNA. Results of analysis will be compared with the measured noise figures of CMOS LNA with double inputs fabricated in 0.18 $\mu\textrm{m}$ CMOS process. Additionally, analyzing the contributions of FET channel noise and source noise from the LNA operating in the other band, this paper proposes optimum matching topology which minimizes the added noises for concurrent operation.

• Journal of electromagnetic engineering and science
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• v.17 no.4
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• pp.197-201
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• 2017

In this paper, we present a novel design for a dual-band bandpass filter (BPF) based on the conventional second-order, open-loop BPF. By adding series resonant circuits to the open ends of the resonator, we can create two resonant modes from the even and odd modes. One pair of the even and odd modes constitutes the upper passband, while the other pair constitutes the lower passband. By adding another series resonant circuit to the open-loop resonator, we can control the bandwidth of either the upper passband or the lower passband. We can replace the series resonant circuits with simple microstrip line resonators. A dual-band BPF working at both Wi-Fi bands (2.4 GHz and 5.8 GHz bands) is designed based on the proposed method and is tested. The measured and simulated results show excellent agreement.

• Journal of applied mathematics & informatics
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• v.5 no.3
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• pp.797-804
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• 1998

A pair of multiobjective generalized symmetric dual non-linear programming problems and weak strong and converse dual-ity theorems for these problems are established under generalized $\rho-(\eta,0)$-invexity assumptions. Several known results are obtained as special cases.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.3
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• pp.301-310
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• 2004

In this paper, a compact dual-mode filter structure without coupling gaps is proposed. The novel design is achieved by embedding a pair of equal crossed slots and spur-lines. Without coupling gaps between feed lines and patch resonator, the new filter can provide low insertion loss. It is found that this design has wide coupling range for dual-mode operation. It means that these characteristics of the proposed filter can reduce uncertainty in fabrication. By using two PIN diodes mounted inside a pair of spur-lines, the proposed structure works as a switchable filter. Also, it has a size reduction of about 34.7 %, compared with conventional dual-mode filters.

• Communications of the Korean Mathematical Society
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• v.34 no.2
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• pp.401-414
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• 2019

Let ${\mathcal{F}}$ denote an algebraically closed field with characteristic not two. Fix an integer $d{\geq}3$, let $Mat_{d+1}({\mathcal{F}})$ denote the ${\mathcal{F}}$-algebra of $(d+1){\times}(d+1)$ matrices with entries in ${\mathcal{F}}$. An ordered pair of matrices A, $A^*$ in $Mat_{d+1}({\mathcal{F}})$ is said to be LB-TD form whenever A is lower bidiagonal with subdiagonal entries all 1 and $A^*$ is irreducible tridiagonal. Let A, $A^*$ be a Leonard pair in $Mat_{d+1}({\mathcal{F}})$ with fundamental parameter ${\beta}=2$, with this assumption there are four families of Leonard pairs, Racah, Hahn, dual Hahn, Krawtchouk type. In this paper we show from these four families only Racah and Krawtchouk have LB-TD form.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.163-169
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• 2012

Since only one application has monopoly on LCD device of the mobile device in Android platform, the user can not see two screens together displayed by two applications running simultaneously. In this paper, a dual-app has been defined as two mobile applications running on each device of a pair of two mobile devices and DSAP or Dual Screen Android Platform has been implemented. DSAP does remote-execution of the peer application of a dual-app on the peer mobile device when either application of the dual-app starts to run and supports communication of the pair app over the network. This paper describes details of design and implementation of DSAP and shows a sample case utilizing DSAP.

• Journal of applied mathematics & informatics
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• v.26 no.3_4
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• pp.549-561
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• 2008

In this paper, we construct a pair of Wolfe type second order symmetric dual problems, in which each component of the objective function contains support function and is, therefore, nondifferentiable. For this problem, we validate weak, strong and converse duality theorems under bonvexity - boncavity assumptions. A second order self duality theorem is also proved under additional appropriate conditions.

• Journal of applied mathematics & informatics
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• v.19 no.1_2
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• pp.1-17
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• 2005

In this paper we present a pair of operators (t-norm, t-conorm) dual with a strong negation with n-threshold $a_1,\;{\ldots}, a_n\;{\in}(0,1),\;a_1\;<\;a_2\;<\;{\ldots}\;<\;a_n$. In this way we obtain an extension of operators with threshold, that are obtained for n = 1. The new pair is obtained from given one.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1241-1242
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• 2013