• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.9
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• pp.570-576
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• 2005

In FIR (Finite Impulse Response) filter applications, Nth-band FIR digital filters are known to be important due to their reduced computational requirements. The conventional methods for designing FIR filters use iterative approaches such as the well-known Parks-Mcclellan algorithm. the Parks-Mcclellan algorithm is also used to design Nth-band FIR digital filters. But a disadvantage of the Parks-McClellan algorithm Is that it needs a good amount of design time. This paper describes a direct design method for third-band FIR Filters using Chebyshev polynomial, which provide a reduction in design time over indirect methods such as the Parks-McClellan algorithm. The response of the resulting filter is equi-ripple in passband. The proposed method of design produces a passband response that is equi-ripple to within a minuscule error, compare to that of the Parks-McClellan algorithm.

• Journal of the Korean Data and Information Science Society
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• v.17 no.2
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• pp.401-409
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• 2006

We consider a generalized partly-parametric additive risk model which generalizes the partly parametric additive risk model suggested by McKeague and Sasieni (1994). As an estimation method of this model, we propose to use the weighted least square estimation, suggested by Huffer and McKeague (1991), for Aalen's additive risk model by a piecewise constant risk. We provide an illustrative example as well as a simulation study that compares the performance of our method with the ordinary least squares method.

• Communications of the Korean Mathematical Society
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• v.22 no.4
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• pp.623-640
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• 2007

The Lotka-McKendrick model which describes the evolution of a single population is developed from the well known Malthus model. In this paper, we introduce the Lotka-McKendrick model. We approximate the solution to the model using hp-discontinuous Galerkin finite element method. The numerical results show that the presented hp-discontinuous Galerkin method is very efficient in case that the solution has a sharp decay.

• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.419-424
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• 2016

$H_5PMo_{10}V_2O_{40}$ ($PMo_{10}V_2$) catalyst chemically immobilized on sulfur-containing mesoporous carbon (S-MC) was prepared, and it was applied to the benzyl alcohol oxidation reaction. S-MC was synthesized by a templating method using SBA-15 and p-toluenesulfonic acid as a templating agent and a carbon precursor, respectively. S-MC was then modified to have a positive charge, and thus, to provide sites for the immobilization of $PMo_{10}V_2$. By taking advantage of the overall negative charge of $[PMo_{10}V_2O4_{40}]^{5-}$, $PMo_{10}V_2$ catalyst was immobilized on the S-MC support as a charge matching component. It was revealed that $PMo_{10}V_2$ species were finely and molecularly dispersed on the S-MC via chemical immobilization. In the vapor-phase oxidation of benzyl alcohol, $PMo_{10}V_2$/S-MC catalyst showed higher conversion of benzyl alcohol and higher yield for benzaldehyde and benzoic acid than unsupported $PMo_{10}V_2$ catalyst. The enhanced catalytic performance of $PMo_{10}V_2$/S-MC was due to fine dispersion of $PMo_{10}V_2$ species on the S-MC via chemical immobilization.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.22 no.2
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• pp.1-18
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• 2009

Objective : Moutan Cortex (the root bark of Paeonia suffruticosa Andr.) is widely used in oriental medicine as a remedy for inflammation. However, as yet there is no clear explanation of how MC(Moutan Cortex) affects the production of inflammatory cytokine. This study was to determine the effects of Essence extracted MC on the mast cell-mediated inflammatory responses. Method : We observed the effect of MC on compound 48/80-induced histamine release of rat peritoneal mast cells and the effect of administering MC on PCA in rat. We measured the amount of inflammatory cytokine production induced by the phorbol myristate acetate (PMA) plus calcium ionophore(A23187) in the human mast cell line (HMC-1) incubated with various concentrations of MC. The TNF-$\alpha$ protein levels were analysised by Western blot. The TNF-$\alpha$, IL-6 and IL-8 secreted protein levels were measured by the ELISA assay. The TNF-$\alpha$, IL-6 and IL-8 mRNA levels were measured by the RT-PCR analysis. NF-$\kappa$B, phospho-I$\kappa$B and MAPKs were exmined by Western blot analysis. The NF-$\kappa$B promoter activity was examined by luciferase assay. Result : 1. Enzyme immunoassay indicated that MC suppressed histamine secretion of rat peritoneal mast cells. 2. In PCA dependent on IgE, MC had anti-allergic effect of the internal surface of rat skin. 3. Western blot indicated that MC decreased TNF-$\alpha$ protein levels. 4. ELISA indicated that MC decreased TNF-$\alpha$, IL-6 but MC had no significant effect on IL-8 in HMC-1 cells. 5. RT-PCR indicated that MC decreased TNF-$\alpha$, IL-8 but MC had no significant effect on IL-6 in HMC-l cells. 6. Western blot indicated that MC suppressed the induction of MAPKs, NF-$\kappa$B & phospho-I$\kappa$B activity in HMC-1 cells. 7. Luciferase assay indicated that MC suppressed the PMA plus A23187-induced NF-$\kappa$B promoting activityin HMC-1 cells. Conclusion : In this study, we have found that MC is an inhibitor of NF-$\kappa$B, MAPKs & cytokines on the mast cell-mediated inflammatory responses.

• Structural Engineering and Mechanics
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• v.82 no.3
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• pp.271-282
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• 2022

The active learning surrogate model based on adaptive sampling strategy is increasingly popular in reliability analysis. However, most of the existing sampling strategies adopt the trial and error method to determine the size of the Monte Carlo (MC) candidate sample pool which satisfies the requirement of variation coefficient of failure probability. It will lead to a reduction in the calculation efficiency of reliability analysis. To avoid this defect, a new method for determining the optimal size of the MC candidate sample pool is proposed, and a new structural reliability analysis method combining polynomial chaos-based Kriging model (PC-Kriging) with adaptive sampling region is also proposed (PCK-ASR). Firstly, based on the lower limit of the confidence interval, a new method for estimating the optimal size of the MC candidate sample pool is proposed. Secondly, based on the upper limit of the confidence interval, an adaptive sampling region strategy similar to the radial centralized sampling method is developed. Then, the k-means++ clustering technique and the learning function LIF are used to complete the adaptive design of experiments (DoE). Finally, the effectiveness and accuracy of the PCK-ASR method are verified by three numerical examples and one practical engineering example.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.4
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• pp.331-336
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• 2011

Purpose: McNamara and Delaire analyses are two commonly used analytic methods, yet, they differ in their theoretic concepts and different reference lines are used for ideal surgical prediction. Therefore, the use of different analytic methods may result in different surgical plans. The purpose of this study was to compare the anterior and posterior relationship of the maxilla and mandible by using McNamara and Delaire analysis. Methods: 30 Korean patients (15 male and 15 female) who had visited the Department of Oral and Maxillofacial Surgery, College of Dentistry, Yonsei University, for dentofacial evaluation were studied by using McNamara's and Delaire's analyses. Results: On the maxillary analysis, 26 out of 30 patients (86.7%) were in accordance. On the mandibular analysis, 20 out of 30 patients (66.7%) were in accordance. On the maxillary analysis, McNamara's analysis showed an average of 0.36 mm greater amount of prognathism compared to Delaire's analysis, and this was not statistically significant. On the mandibular analysis, McNamara's analysis showed an average of 6.03 mm greater amount of prognathism compared to Delaire's analysis, and this was statistically significant. On the mandibular analysis, 26 out of 30 patients (86.7%) showed a greater amount of prognathism on McNamara's analysis compared to that of Delaire's analysis. The remaining 4 patients (13.3%) showed the same amount of prognathism on both analyses. Conclusion: These results may serve as a reference for surgeons when determining which analytic method is to be used for optimal surgical results.

• Journal of KIISE:Software and Applications
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• v.27 no.10
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• pp.1003-1014
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• 2000

MPEG은 동영상 압축 규약의 하나로서 고하질을 유지하면서 높은 압축율을 제공하기 때문에 그 사용 범위가 점차로 넓어지고 있으며, 또한 이러한 이유로 인해서 MPEG 데이터에 대한 편집 시스템의 요구도 점차 증가되고 있다. 그러나. MPEG 스트림에 대한 편집은 대부분 공간 영역에서 수행되기 때문에 수행 시간이 오래 걸리고 화질이 저하된다는 단점을 안고 있다. 본 논문에서는 DC 이미지를 이용한 MC-DCT 영역에서의 자막 처리 방법을 제안함으로써 기존의 자막 처리 방법이 안고 있는 단점을 극복하도록 하였다. 제안한 방법에서는 MC-DCT 영역에서의 워터마크 삽입 방법[1]을 응용하여 빠른 처리가 가능하도록 하였으며, MC-DCT 영역에서 쉽게 구할 수 있는 DC 이미지를 이용하여 화면 상태에 따라 자막의 세기를 조절함으로써 P,B 프레임의 처리 과정에서 발생하게 되는 화질 저하를 최소화하도록 하였다. 이러한 MC-DCT 영역에서의 자막 방법을 사용함으로써 기존의 자막 처리 방법 보다 약 4.9배 빠른 수행 속도를 얻을 수 있었으며, 화질 보존의 측면에서도 기존의 자막 처리 방법이 화면 전체에 대해서 화질 저하가 발생하는 반면 제안한 방법은 자막이 들어가는 부분에 대해서만 화질 저하가 발생하였다. 이러한 방법을 MPEG 스트림에 대해서 사용하게 된다면, 소프트웨어만을 이용한 저가의 데스크 탑 환경에서도 효율적인 자막 처리가 가능하게 될 것이다.

• Toxicological Research
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• v.22 no.3
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• pp.301-306
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• 2006

Microcystin-LR(MC-LR), a cyanobacterial toxin produced by Microcystis aeruginosa, causes severe hepatotoxicity. Here we investigated the morphologic changes of rat hepatocyte spheroid induced by exposure of MC-LR($10^{-6}M$) in vitro. In addition, to determine the effects of such toxin in the process of hepatocyte spheroid formation, primarily isolated hepatocytes were incubated with MC-LR and the process of spheroid formation was observed. In both hepatocyte spheroid and suspension culture systems, the morphologic changes caused by MC-LR were noticible at 5 min post exposure and were characterized by the loss of microvilli, cytoplasmic vacuolation, the accumulation of lipid droplets, and blob formation. Especially, the size and numbers of blob on the cell surface were increased as the incubation time prolonged and the appearance of electron dense bodies were observed in the cytoplasm of hepatocyte at 20 min post exposure. Furthermore, bile canaliculi-like structures in the hepatocyte spheroids were slightly widened and the process of spheroids formation was inhibited in the isolated hepatocytes incubated with MC-LR. These results indicate that morphologic changes in. the hepatocyte membrane and organelles seem to be typical events in showing the MC-LR induced hepatotoxic effects and the spheroid culture method might be a useful experimental tool to evaluate hepatoxicity since it reflects the in vivo status of hepatocytes.

• Journal of Korea Society of Industrial Information Systems
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• v.10 no.1
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• pp.1-8
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• 2005

Multicarrier code division multiple access(MC-CDMA) Is a scheme that combines multicarrier modulation with CDMA. It offers robustness to frequency selective fading and can support higher rate data transmission with higher spectral efficiency. The objective of this article to proposed a new asynchronous ME-CDMA system to implement multiple data rate communications. It can be accomplished by changing the number of parallel branch(.p). For the analysis of average BER performance, numerical method and computer simulation were used. After MAI power of received signal calculated, the average BER can be acriuired using Gaussian approximation to MAI. We also compare the system performance with that of a single rate MC-CDMA system.