• Communications of the Korean Mathematical Society
• /
• v.19 no.2
• /
• pp.345-354
• /
• 2004

Boente and Fraiman [2] studied robust nonparametric estimators for regression or autoregression problems when the observations exhibit serial dependence. They established strong consistency of two families of M-type robust equivariant estimators for $\phi$-mixing processes. In this paper we extend their results to weaker $\alpha$$alpha$-mixing processes.

• Journal of the Korean Statistical Society
• /
• v.30 no.3
• /
• pp.407-418
• /
• 2001

Buhlmann(1944) established the validity of the block bootstrap proposed by Kunsch when it is applied to p-dimensional $\alpha$-mixing dependent sequence. But his result requires a rather restrictive condition on p in the sense that p is entangled with dependence structure. We address that such restriction on p(or complication of dependence structure with p) could be removed completely when the underlying dependence structure is replace by more weakly dependent structure such as ø-mixing.

• Bulletin of the Korean Mathematical Society
• /
• v.54 no.1
• /
• pp.343-358
• /
• 2017

Let {$X_i$} be a sequence of stationary ${\alpha}-mixing$ random variables with probability density function f(x). The recursive kernel estimators of f(x) are defined by $$\hat{f}_n(x)={\frac{1}{n\sqrt{b_n}}{\sum_{j=1}^{n}}b_j{^{-\frac{1}{2}}K(\frac{x-X_j}{b_j})\;and\;{\tilde{f}}_n(x)={\frac{1}{n}}{\sum_{j=1}^{n}}{\frac{1}{b_j}}K(\frac{x-X_j}{b_j})$$, where 0 < $b_n{\rightarrow}0$ is bandwith and K is some kernel function. Under appropriate conditions, we establish the Berry-Esseen bounds for these estimators of f(x), which show the convergence rates of asymptotic normality of the estimators.

• Journal of the Korean Statistical Society
• /
• v.31 no.3
• /
• pp.359-368
• /
• 2002

Nonparametric kernel regression problem is considered for a stationary dependent sequence ｛(Xi, Yj) 1 j $\geq$ 1 ｝. In particular consistency and rates of convergence are discussed, which gives some useful insight for the effect of dependence for stationary $\alpha$-mixing sequences.

• Korean Journal of Materials Research
• /
• v.4 no.1
• /
• pp.9-23
• /
• 1994

Epitaxial $CoSi_2$ layer has been grown on NaCl(100) substrate at low deposition temperature($200^{\circ}C$) by multitarget bias cosputter deposition(MBCD). The phase sequence and crystallinity of deposited silicide as a function of deposition temperature and substrate bias voltage were studied by X-ray diffraction(XRD) and transmission electron microscopy(TEM) analysis. Crystalline Si was grown at $200^{\circ}C$ by metal induced crystallization(M1C) and self bias effect. In addition to, the MIC was analyzed both theoretically and experimentally. The observed phase sequence was $Co_2Si \to CoSi \to Cosi_2$ and was in good agreement with that predicted by effective heat of formation rule. The phase sequence, the CoSi(l11) preferred orientation, and the crystallinity had stronger dependence on the substrate bias voltage than the deposition temperature due to the collisional cascade mixing, the in-situ cleaning, and the increase in the number of nucleation sites by ion bombardment of growing surface. Grain growth induced by ion bombardment was observed with increasing substrate bias voltage at $200^{\circ}C$ and was interpreted with ion bombardment dissociation model. The parameters of $E_{Ar}\;and \alpha(V_s)$ were chosen to properly quantify the ion bombardment effect on the variation in crystallinty at $200^{\circ}C$ with increasing substrate bias voltage using Langmuir probe.

• Journal of the Korean Vacuum Society
• /
• v.2 no.4
• /
• pp.439-454
• /
• 1993

The phase sequence of codeposited Co-Si alloy and Co/si multilayer thin film was investigated by differential scanning calormetry(DSC) and X-ray diffraction (XRD) analysis, The phase sequence in codeposition and codeposited amorphous Co-Si alloy thin film were CoSilongrightarrow Co2Si and those in Co/Si multilayer thin film were CoSilongrightarrowCo2Silongrightarrow and CoSilongrightarrowCo2Si longrightarrowCoSilongrightarrowCoSi2 with the atomic concentration ration of Co to Si layer being 2:1 and 1:2 respectively. The observed phase sequence was analyzed by the effectvie heat of formatin . The phase determining factor (PDF) considering structural facotr in addition to the effectvie heat of formation was used to explain the difference in the first crystalline phase between codeposition, codeposited amorphous Co-Si alloy thin film and Co/Si multilayer thin film. The crystallinity of Co-silicide deposited by multitarget bias cosputter deposition (MBCD) wasinvestigated as a funcion of deposition temperature and substrate bias voltage by transmission electron microscopy (TEM) and epitaxial CoSi2 layer was grown at $200^{\circ}C$ . Parameters, Ear, $\alpha$(As), were calculate dto quantitatively explain the low temperature epitaxial grpwth of CoSi2 layer. The phase sequence and crystallinity had a stronger dependence on the substrate bias voltage than on the deposition temperature due to the collisional daxcade mixing, in-situ cleannin g, and increase in the number of nucleation sites by ion bombardment of growing surface.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2018.10a
• /
• pp.116-116
• /
• 2018

Bioconversion, the enzymatic process by microorganism on organic precursor to desired products. The natural extract is converted into a form that can be easily absorbed into the skin, while scaling up of to higher quantity is possible. Selection of naturally processed raw material rather than chemically processed is preferred. Therefore, fermentation was carried out by mixing Rubus coreanus Miquel, soybean, Zanthoxylum schinifolium as bioconverting materials, the possibility of inflammation, whitening material were checked. In this study, useful microorganisms were isolated from various salted fish, and 16S rDNA sequence was analyzed to confirm their genetic characteristics. Combining the three natural materials using bioconversion technology to study their activity before and after fermentation. To evaluate the antioxidant activity and the active ingredient content the DPPH radical scavenging activity and the total polyphenol content were examined. Raw 264.7 cells were used to evaluate MTT assay, NO and $TNF-{\alpha}$ production inhibitory activity. Also, to evaluate the whitening activity, tyrosinase inhibitory activity and melanin formation inhibitory activity were measured using B16F10 cells. In total 34 strains were obtained from various salted fish. The effective strains useful for the bioconversion process, showed that DPPH radical scavenging ability and polyphenol content were increased in the two kinds of microbial treatment groups compared to the untreated group. 16S rDNA sequencing analysis of the strains showed excellent in Pediococcus pentosaceus B1 in comparison. An increase of up-to 156% in anti-oxidative activity and 141% in polyphenol content was observed after bioconversion. In addition, after mixed fermentation the toxidty of Raw 264.7 and B16F10 cells tended to decrease and a significant increase was observed in anti-inflammatory activity as well. Also, tyrosinase activity and melanin significantly. synthesis decreased significantly.