• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4A
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• pp.489-495
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• 2000

In this paper we propose an approximate method to estimate the cell loss probability(CLP) due to buffer overflow in ATM networks. The main idea is to relate the buffer capacity with the CLP target in explicit formula by using the approximate upper bound for the tail distribution of a queue. The significance of the proposition lies in the fact that we can obtain the expected CLP by using only the source traffic data represented by mean rate and its variance. To that purpose we consider the problem of estimating the cell loss measures form the statistical viewpoint such that the probability of cell loss due to buffer overflow does not exceed a target value. In obtaining the exact solution we use a typical matrix analytic method for GI/D/1B queue where B is the queue size. Finally, in order to investigate the accuracy of the result, we present both the approximate and exact results of the numerical computation and give some discussion.

• Journal of computational fluids engineering
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• v.12 no.1
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• pp.1-8
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• 2007

A code is developed using the hybrid Cartesian/immersed boundary method and it is applied to simulate flows around a three-dimensional deforming body. A new criterion is suggested to distribute the immersed boundary nodes based on edges crossing a body boundary. Velocities are reconstructed at the immersed boundary nodes using the interpolation along a local normal line to the boundary. Reconstruction of the pressure at the immersed boundary node is avoided using the hybrid staggered/non-staggered grid method. The developed code is validated through comparisons with other experimental and numerical results for the velocity profiles around a circular cylinder under the forced in-line oscillation and the pressure coefficient distribution on a sphere. The code is applied to simulate the flow fields around a plate whose tail is periodically flapping under a translation. The effects of the velocity and acceleration due to the deformation on the periodic shedding of pairs of tip vortices are investigated.

• International Journal of Reliability and Applications
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• v.6 no.1
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• pp.1-12
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• 2005

A new test for testing that a life distribution is exponential against the alternative that it is harmonic new better (worse) than used in expectation upper tail HNBUET (HNWUET), but not exponential is presented based on the highly popular 'Kernel methods' of curve fitting. This new procedure is competitive with old one in the sense of Pitman's asymptotic relative efficiency, easy to compute and does not depend on the choice of either the band width or kernel. It also enjoys good power.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.60.3-61
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• 2018

Abell 115 is a renowned cluster merger at z=0.197. It exhibits an asymmetric X-ray distribution with cometary tails and a megaparsec-sized radio relic stretching in the northeastern direction from the core of the northern cluster. Many observations have concluded that this cluster merger has a large impact parameter, but there has been no numerical analysis on the structure of Abell 115. In this study, we simulate Abell 115 with Gadget2 N-body/SPH code to reproduce the X-ray and weak lensing features of Abell 115. We find a new plausible merger scenario of Abell 115, wherein the northern cluster is currently in an outgoing phase. The predicted X-ray emission has a similar morphology to the observed tail of the northern cluster. However, in order to reproduce the observed line-of-sight velocity and projected distance while maintaining the two systems gravitationally bound, the system should possess a large projection angle, which makes the shock look considerably more diffused than the observed radio relic.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.40-47
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• 2015

Single-walled carbon nanotubes (SWNTs) was modified with various length of linear alkyl chains and passivated to form dielectric filler. The modified SWNTs embedded into epoxy matrix to fabricate a flexible composite with high dielectric constant. The dielectric behavior of the composite was significantly changed with various alkyl chain length(n) of pyrene. The dielectric constant of the epoxy/SWNTs composite significantly increased with respect to increase in length of alkyl chain at the frequency range from 10 to 105Hz (n=12and18).We also found that the passivated epoxy/SWNTs composite with high dielectric constant presented low dielectric loss. The resulted dielectric performances corresponded to de-bundling of nanotubes and their distribution behavior in the matrix in terms of tail length of alkyl pyrene in the passivation layer.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.1C
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• pp.9-13
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• 2003

We consider a two-phase queueing system with Bernoulli feedback. Customers arrive at the system according to a Poison process and receive batch service in the first phase followed by individual services in the second phase. Each customer who completes the individual service returns to the tail of the second phase service queue with probability 1 -$\sigma$. This type of queueing problem cad be easily found in computer and telecommunication systems. By deriving a relationship between the generating functions for system size at various embedded epochs, we obtain the system size distribution. The exhaustive and gated cases for the batch service are considered.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1290-1294
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• 2004

In this study, new stochastic point rainfall models which can consider the correlation structure between rainfall intensity and duration are developed. In order to consider the negative and positive correlation simultaneously, the Gumbels type-II bivariate distribution is applied, and for the cluster structure of rainfall events, the Neyman-Scott cluster point process is selected. In the theoretical point of view, it is shown that the models considering the dependent structure between rainfall intensity and duration have slightly heavier tail autocorrelation functions than the corresponding independent mode]s. Results from generating long time rainfall events show that the dependent models better reproduce historical rainfall time series than the corresponding independent models in the sense of autocorrelation structures, zero rainfall probabilities and extreme rainfall events.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.225-235
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• 2014

6종의 Intermediate filament 중 type IV인 Neurofilaments (NFs)는 신경세포에 존재하는 세포골격세사로 heavy NF(NF-H), medium NF(NF-M), light NF(NF-L) 세가지의 분자 질량 단백질로 구성되어 있다. NF의 side arm은 interfilament spacing과 axonal caliber를 조절하는 중요한 역할을 한다고 생각되어왔다. 또한 이에 대해서 각각의 protein의 역할은 알아내기 위해 isolated NF의 형태와 구조에 대해 많은 연구가 이루어졌는데, NF의 구조적 특성은 NF sidearm의 tail 부분에서 phosphorylation의 정도에 따른 Lys-Ser-Pro(KSP) repeats의 charge distribution을 통해 알 수 있다. 지금까지 NF에 대한 많은 연구가 이루어졌지만 인간에 한해서만 진행되었다. 그렇기 때문에 본 연구에서는 주어진 amino acid sequence와 각 species의 NF-H:NF-M:NF-L의 비율의 정보를 이용하여 The constant-NVT ensemble MC simulation을 통해 인간뿐만이 아닌 다른 species에 대한 NF의 구조적 특성을 알아보고자 한다.

• Archives of Pharmacal Research
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• v.18 no.1
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• pp.8-11
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• 1995

Biodegradability of poly $Poly({\gamma}-benzyl L-Glutamate)/poly(ethylene oxide)/Poly({\gamma}-benzyl L-Glutamate)$ block copolymer (GEG) having different content of poly(ethylene oxide) (PEO) were examined using magnetite as a tracer in mice. GEG microspheres containing magnetite were injected into mice through tail vein. Biodegradability and tissue distribution of microspheres were examined by analyzing the amount of magnetite in the microspheres recollected from mice organs after specific time interval. The results showed that GEG microsphere of high content of PEO was degraded more rapidly than those of low content of PEO in the mice organs.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.4
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• pp.216-225
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• 2013

This paper discusses the issues regarding an abnormal V-shaped error confronting algebraic-based deconvolution process. Deconvolution was applied to an analysis of the effects of the Random Telegraph Noise (RTN) and Random Dopant Fluctuation (RDF) on the overall SRAM margin variations. This paper proposes a technique to suppress the problematic phenomena in the algebraic-based RDF/RTN deconvolution process. The proposed technique can reduce its relative errors by $10^{10}$ to $10^{16}$ fold, which is a sufficient reduction for avoiding the abnormal ringing errors in the RTN deconvolution process. The proposed algebraic-based analyses allowed the following: (1) detection of the truncating point of the TD-MV distributions by the screening test, and (2) predicting the MV-shift-amount by the assisted circuit schemes needed to avoid the out of specs after shipment.