• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2001년도 추계학술발표논문집
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• pp.699-702
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• 2001

본 논문에서는 비트 플래인 상에서 지역적인 복잡도를 이용하여 커버 이미지를 분할한 후 비밀 데이터를 삽입하는 스테가노그라피 방법을 연구하였다. 이 방법은 복잡도를 이용하여 비트 플래인 이미지를 informative 영역과 noise-like 영역으로 나누고, noise-like 영역에 데이터를 삽입한다. 삽입되는 데이터가 간단하다면 image conjugation을 적용하여 복잡한 형태로 만들어 커버 이미지에 삽입한다. 본 연구에서는 삽이 용량을 증가시키기 위해 복잡도를 모든 비트 플래인에 적용시키지 않고, 선택적으로 적용하여 46%의 최대 삽입용량과 화질의 증가를 얻을 수 있었다.

• Transactions on Electrical and Electronic Materials
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• 제15권2호
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• pp.55-59
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• 2014

An implantable CPW fed monopole 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 (${\Box}_r=9.8$ and thickness=0.65 mm). The proposed antenna covers the ISM band of 2.45 GHz. The radiation parameters, such as return loss, E-Plane, H-Plane, are measured and analyzed, using the method of moments. The proposed antenna has substantial merits over other implanted antennas, like low profile, miniaturization, lower return loss, and better impedance matching and high gain.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1996년도 봄 학술발표회 논문집
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• pp.182-189
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• 1996

The focus of this study is on the problem of the design of structure of undetermined topology. This problem has been regarded as being the most challenging of structural optimization problems, because of the difficulty of allowing topology to change. Conventional approaches break down when element sizes approach to zero, due to stiffness matrix singularity. In this study, a novel nonlinear Programming formulation of the topology Problem is developed and examined. Its main feature is the ability to account for topology variation through zero element sizes. Stiffness matrix singularity is avoided by embedding the equilibrium equations as equality constraints in the optimization problem. Although the formulation is general, two dimensional plane elasticity examples are presented. The design problem is to find minimum weight of a plane structure of fixed geometry but variable topology, subject to constraints on stress and displacement. Variables are thicknesses of finite elements, and are permitted to assume zero sizes. The examples demonstrate that the formulation is effective for finding at least a locally minimal weight.

• 한국지능시스템학회논문지
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• 제17권2호
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• pp.259-264
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• 2007

본 본문은 Arnold 방정식, Chua's 방정식과 같은 여러 종류의 카오스 회로를 이동 로봇에 내장하여 카오스 이동 로봇을 구성하고 이 카오스 이동 로봇이 어느 임의 평면을 카오스 궤적을 가지고 탐색하다가 장해물을 만나거나 근접하게 되면 장해물을 회피하는 방법과 목표물을 만나면 목표물을 집중 탐색하는 방법을 제시하고 그 결과를 검증하였다. 장해물 회피를 위해서 장해물을 고정 장해물과 BVP 모델을 이용한 은닉 장해물로 장해물을 가정하여 카오스 궤적을 가지고 회피하도록 하는 알고리즘을 개발하고 목표물 탐색을 위해서 BVP 모델을 이용하여 목표물로 가정하여 카오스 궤적을 가지고 집중적으로 탐색하도록 하는 알고리즘을 개발하고 그 결과를 검증하였으며 이에 대한 타당성을 확인하였다.

• 전자공학회논문지A
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• 제33A권6호
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• pp.81-89
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• 1996

Quantum RF impedance of SIS (superconductor insulator superconductor) junction has been analyzed by using through on tucker's quantum mixer theory in the frequency range form 80 GHz to 120 GHz. The embedding impedance of waveguide-type mixer mount and its equivalent circuit have been evaluated. From these evaluated results, the impedance matching efficiency between mixer mount embedding impedance and mixer port impedance of upper-side band and IF which were determined by augmented admittance matrix with given backshort position has been discussed in detail. It is found that the mixer with fixed backshort mount ahs a impedance matching efficiency about 80% at each port of mixer within 85GHz to 115GHz, which implys a conversion los of mixer would be good enough to be operated such a wide band frequency range. Therefore, the theoretical evaluated results show that our method can be used ot design the mixer mount without any mechanical tuning elements such a backshort or an E-plane tunners for wide band operation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.542-544
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• 1997

The analysis of distribution line faults is essential to the proper protections in the power system. A high impedance fault does not make enough current to cause conventional protective devices. In this paper, Fractal dimensions are estimated for distinction between normal status and fault status in the power system. Application of the concepts of the fractal geometry to analyze chaotic properties of high impedance fault current was described. In addition, to analyze variation of fault current and normal current on phase plane, embedding state variables are reconstructed from 1 dimensional time series.

• 대한수학회보
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• 제53권3호
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• pp.885-902
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• 2016

In this paper we begin the study of $L_k$-2-type hypersurfaces of a hypersphere ${\mathbb{S}}^{n+1}{\subset}{\mathbb{R}}^{n+2}$ for $k{\geq}1$ Let ${\psi}:M^3{\rightarrow}{\mathbb{S}}^4$ be an orientable $H_k$-hypersurface, which is not an open portion of a hypersphere. Then $M^3$ is of $L_k$-2-type if and only if $M^3$ is a Clifford tori ${\mathbb{S}}^1(r_1){\times}{\mathbb{S}}^2(r_2)$, $r^2_1+r^2_2=1$, for appropriate radii, or a tube $T^r(V^2)$ of appropriate constant radius r around the Veronese embedding of the real projective plane ${\mathbb{R}}P^2({\sqrt{3}})$.

• 대한전자공학회논문지
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• 제24권6호
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• pp.1068-1073
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• 1987

Traditional circuit partitioning algorithm using the cluster development method, which is suitable for such applications as single chip floor planning or multiple layer PCB system placement, where the clusters are formed so that inter-cluster nets are localized within the I/O connector pins, may not be appropriate for the functiona block placement in truly 3-D electronic modules. 3-D hybrid IC is one such example where the inter-layer routing as well as the intra-layer routing can be maximally incorporated to reduce the overall circuit size, cooling requirements and to improve the speed performance. In this paper, we propose a new algorithm called MBE(Minimum Box Embedding) for the layer assignment of each functional block in 3-D hybrid IC design. The sequence of MBE is as follows` i) force-directed relaxation in 3-D space, ii) exhaustive search for the optimal orientation of the slicing plane and iii) layer assignment. The algorithm is first explaines for a 2-D reduced problem, and then extended for 3-D applications. An example result for a circuit consisting of 80 blocks has been shown.

• Journal of information and communication convergence engineering
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• 제4권1호
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• pp.28-35
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• 2006

In this paper, we propose to synchronization method for mutual cooperative control method that have unstable limit cycles in a chaos trajectory surface in the chaotic UAVs. We assume all obstacles in the chaos trajectory surface have a Van der Pol equation with an unstable limit cycle. We also show computer simulation results of Arnold equation, Chua's equation trajectories with one or more Van der Pol as a obstacles. We proposed and verified the results of the method to make the embedding chaotic UAV to synchronization with the chaotic trajectory in any plane.

• 한국전자통신학회논문지
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• 제8권11호
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• pp.1691-1696
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• 2013

본 논문에서는 순환형 하이브리드 초소형 에너지 수확장치 장치에서 존재하는 거동해석을 수행한다. 이 거동해석은 더 많은 에너지를 생산하기 위해서 비선형 시스템이 요구되므로 비선형 시스템의 존재 유무를 확인하는 것이다. 이를 위해 먼저 타켄스의 매립법을 통한 위상 공간을 재구성한다. 또한 위상 공간을 이용하여 포엔카래 맵을 구성하고 리아프노프 지수를 구하여 분석한다.