• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.200.2-200.2
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• 2015

모바일 기기의 성장세로 인해 낸드 플래시 메모리에 대한 수요가 급격히 증가하면서 높은 집적도의 소자에 대한 요구가 커지고 있다. 그러나 소자의 크기가 작아지면서 비례 축소로 인한 게이트 누설 전류, 셀간 간섭, 단 채널 효과 등과 같은 문제들이 발생한다. 이에 따라 제한된 공간에서의 coupling ratio값이 증가해야 하는 문제가 주목 받으면서 얇은 절연층에 대한 많은 연구가 진행되고 있다. 본 연구에서는 절연층 구조를 비대칭으로 사용한 낸드 플래시 메모리의 누설전류의 변화와 coupling ratio값의 변화를 관찰하였다. 비대칭 절연층 구조를 가지는 낸드 플래시 메모리의 전기적 특성을 멀티 오리엔테이션 모델을 포함한 3차원 TCAD 시뮬레이션을 이용하여 계산하였다. 메모리 소자가 각 셀 간의 절연층을 가질 때 낮은 셀 간 간섭과 높은 coupling ratio 값을 가진다. 절연층의 구조 높이와 방향의 두께가 증가 할수록 게이트 누설 전류의 값이 크게 줄어들었다. 또한 비대칭 절연층 구조의 플래시 메모리에서 플로팅 게이트의 on-current 레벨과 전위 값이 기존의 플래시 메모리에 비해 크게 나타나는 시뮬레이션 결과값을 관찰하였다. 비대칭 절연층 구조를 가지는 플래시 메모리는 게이트 누설 전류에 영향을 미치는 절연층 주위의 전기장의 값이 기존 구조에 비해 약 30% 감소하였고 같은 프로그램 동작 전압에서 플로팅 게이트에 주입되는 전하의 양 또한 증가하였다. 이 연구 결과는 낸드 플래시 메모리 소자에서 게이트 누설 전류 문제를 감소시키고 프로그램 특성을 증진시키는데 도움이 된다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.63-69
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• 2010

In this paper, a new design method of asymmetrical configuration of main amplifier and peaking amplifier using changed bias point is proposed for excellent linearity, instead of the conventional Doherty structure. We have utilized the uneven wilkinson power divider for the unequal power drive at the input network of amplifiers. And we proposed a compensating method of the decreasing efficiency due to improving linearity using 3-stage Doherty structures. From the simulation results of asymmetrical Dohertry power amplifier and asymmetrical 3-stage Doherty power amplifier with uneven power drive are implemented. From the implementation and measurement results of the each amplifier, IMD characteristics have -55 dBc as the good efficiency of 13% compensates the decreased entire efficiency due to the improving linearity characteristics.

• Environmental and Resource Economics Review
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• v.16 no.1
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• pp.3-26
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• 2007

This paper analyzes the effects of asymmetric reimbursement in a delegate model where the lawyers for a citizen and a polluting firm work on a contingent-fee basis. The major findings from the paper are as follows: (i) the asymmetric reimbursement triggers environmental conflicts by increasing the citizens' expected surplus; (ii) it enhances the possibility of settlement by decreasing the magnitude of expected loss less expected surplus; (iii) settlements reduce the total litigation effort levels, thus curtailing the rent dissipation; (iv) The total litigation effort levels increase if the conflicts result in trials rather than settlements.

• The Korean Journal of Applied Statistics
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• v.24 no.5
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• pp.821-831
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• 2011

It has been relatively incomplete in the field of financial time series to adapt asymmetric features to multivar ate GARCH processes (McAleer et al., 2009). Retaining constant conditional correlation(CCC) structure, this article pursues to introduce asymmetric GARCH modelling in analysing multivariate volatilities in time series in a practical point of view. Multivariate Korean financial time series are analyzed in detail to compar our theory with conventional methodologies including GARCH and EGARCH.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.3
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• pp.37-44
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• 1997

In this paper, the inelastic behavior of an asymmetric tall building is investigated. The asymmetry in rigidity caused by the structural asymmetry induces torsional as well as lateral deformation. The inelastic analysis of such an asymmetric structure is difficult to carry out with a planar model and thus requires a full three dimensional model. In this paper a 102 story unsymmetric tall building is analized by static push-over procedure and its behavior is investigated. The analysis are performed with and without floor rotation to compare the results. According to the results the static behavior of the model building, as expected, turned out to be dependent heavily an the asymmetry of the plan shapes of the building.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.219-224
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• 2015

Recently, the multi-core processor architecture is widely used in the digital signal processors for enhancing its performance. Multi-core processors are classified either as symmetric or asymmetric. Asymmetric multi-core processors are known to have higher performance and more efficient than symmetric multi-core processors. In order to study the performance enhancement of asymmetric multi-core digital signal processors over the symmetric ones, the trace-driven simulation has been executed for various asymmetric quad-core, octa-core and hexadeca-core digital signal processors and compared with the symmetric ones of similar hardware budget using UTDSP benchmarks as input.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.4
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• pp.187-192
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• 2017

Rigorous longitudinal modal transmission-line theory (L-MTLT) is applied to analyze maximum power transfer in asymmetric grating-assisted directional couplers(A-GADC). By defining a coupling efficiency amenable to rigorous analytical solutions and interference between symmetric and asymmetric supermodes, the power exchange of TE modes as a function of propagation distance is numerically evaluated. The numerical result reveals that maximum power transfer occurs at a grating period ${\Lambda}_{eq}$, in which the insertion loss of supermodes is equal to each other. That is, it is generally different from conventional phase-matching condition of GADC. Furthermore, as the asymmetric profile of grating change to symmetrical profile, the coupling length decreases and the coupling efficiency for power transmission increases.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.11
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• pp.1437-1443
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• 2011

Thick plates produced by the rolling process are used as the basic elements of ship structures. In this paper, we present a setup model for controlling the asymmetric factors causing plate bending in the width direction during plate rolling. A series of three-dimensional finite element analyses is conducted to predict the relationship between various asymmetric factors and plate bending. The setup model is developed by performing regression on the relationship to produce linear equations with several nondimensional parameters. The setup model is verified with a pilot rolling test in which variations in thickness and temperature differences in the width direction exist. The results show that the bending curvatures predicted by the model are in fairly good agreement with the measured results for those asymmetric factors.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.3
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• pp.87-93
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• 2002

A procedure for figuring out proper amount of additional viscous damping required to keep the inelastic deformation of a plan-wise asymmetric structure within a given target performance point was developed. To this end the behavior of an asymmetric nonlinear structure after yielding is investigated. Then a formula for the required amount of equivalent damping was derived based on the ductility demand of the structure. The procedure was applied to a five-story asymmetric structure subjected to an earthquake load. According to the comparison with the results from the dynamic time-history analysis, the structure with viscous dampers installed in accordance with the proposed procedure showed satisfactory seismic performance in both the stiff and the flexible edges.

• Journal of KIISE:Information Networking
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• v.31 no.2
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• pp.179-187
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• 2004

Password authenticated key exchange protocols for the symmetric model are easier to design, analyze and are more efficient than ones for the asymmetric model, but they are most likely to be broken by server's compromise. Though the protocols with provable security for the asymmetric model such as PAK-X and SNAPI-X are introduced, they need large amount of computation compared with the standard Diffie-Hellman key exchange. We present a systematic and efficient way to transform password authenticated key exchange protocols for the symmetric model into protocols for the asymmetric model. Thus, an efficient protocol for the asymmetric model can be constructed by a systematic protocol with low computation.