• Title/Summary/Keyword: Sample splitting

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A Note on Adaptive Estimation for Nonlinear Time Series Models

  • Kim, Sahmyeong
    • Journal of the Korean Statistical Society
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    • v.30 no.3
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    • pp.387-406
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    • 2001
  • Adaptive estimators for a class of nonlinear time series models has been proposed by several authors. Koul and Schick(1997) proposed the adaptive estimators without sample splitting for location-type time series models. They also showed by simulation that the adaptive estimators without sample splitting have smaller mean squared errors than those of the adaptive estimators with sample splitting. the present paper generalized the result in a case of location-scale type nonlinear time series models by simulation.

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Automated Chromosome Samples Extraction using Region Splitting Method (영역분할 기법을 이용한 염색체 표본 자동추출)

  • Eom, Sang-Hee;Jeon, Gye-Rok;Lee, Kwon-Soon;Chang, Yong-Hoon;Lee, Sang-Yeol
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.05
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    • pp.127-130
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    • 1995
  • Chromosome analysis is an important and difficult task for clinical diagnosis, for mutagen dosimetry, and for biological research. It is expensive, time consuming and imprecise when performed manually. Efforts lo automate some or all of the procedures have continued for more than 30 years, with only limited success. An acquiring sample from chromosome group is not solved with automatic method. It is still performed by user. This paper represents the method of an automatic chromosome sample extraction which based on region splitting, and scan converted method.

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Hydrogen Storage Characteristics Using Redox of $M/Fe_2O_3$ (M = Rh, Ce and Zr) Mixed Oxides ($M/Fe_2O_3$ (M = Rh, Ce 및 Zr) 혼합 산화물의 산화-환원을 이용한 수소 저장 특성)

  • Ryu, Jae-Chun;Lee, Dong-Hee;Kim, Young-Ho;Yang, Hyun-Soo;Park, Chu-Sik;Wang, Gab-Jin;Kim, Jong-Won
    • Transactions of the Korean hydrogen and new energy society
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    • v.17 no.1
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    • pp.21-30
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    • 2006
  • [ $M/Fe_2O_3$ ] (M=Rh, Ce and Zr) mixed oxides were prepared using urea method to develop a medium for chemical hydrogen storage by their redox cycles. And their redox behaviors by repeated cycles were studied using temperature programmed reaction(TPR) technique. Additives such as Rh, Ce and Zr were added to iron oxides in order to lower the reaction temperature for reduction by hydrogen and re-oxidation by water-splitting. From the results, concentration of urea used as a precipitant had little effect on particle size and reduction property of iron oxide. TPR patterns of iron oxide consisted of two reduction peaks due to the course of $Fe_2O_3\;{\rightarrow}\;Fe_3O_4\;{\rightarrow}\;Fe$. The results of repeated redox tests showed that Rh added to iron oxide have an effect on lowering the re-oxidation temperature by water-splitting. Meanwhile, Ce and Zr additives played an important role in prevention of deactivation by repeated cycles. Finally, Fe-oxide(Rh, Ce, Zr) sample added with Rh, Ce and Zr showed the lowest re-oxidation temperature by water-splitting and maintained high $H_2$ recovery in spite of the repeated redox cycles. Consequently, it is expected that Fe-oxide(Rh, Ce, Zr) sample can be a feasible medium for chemical hydrogen storage using redox cycle of iron oxide.

Automatic Mesh Generation with Quadrilateral Finite Elements (사각형 유한요소망의 자동생성)

  • 채수원;신보성;민중기
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.12
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    • pp.2995-3006
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    • 1993
  • An automatic mesh generation scheme has been developed for finite element analysis with two-dimensional, quadrilateral elements. The basic strategies of the method are to transform the analysis domain into loops with key nodes and the loops are recursively subdivided into subloops with the use of best split lines. Finally by using the basic loop operators, the meshes are completed. In this algorithm an eight-node loop operator is proposed, which is useful in the area where the change of element size is large and the splitting criteria for subdividing the loops have also been modified to the existing algorithms. Lines, arcs, and cubic spline curves are used to define the boundaries of analysis domain. Sample meshes for several geometries are presented to demonstrate the robustness of the algorithm.

A Study on Photoreflectance in $In_xGa_{1-x}As$(x=0.02) Epilayer Grown by MBE (MBE법으로 성장시킨 $In_xGa_{1-x}As$ (x=0.02) 에피층에서의 Photoreflectance에 관한 연구)

  • 김인수;이정열;배인호;김상기;안행근;박성배
    • Journal of the Korean Vacuum Society
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    • v.5 no.2
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    • pp.127-132
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    • 1996
  • We measured photoreflectance spectrum characteristics of InGaAs grown by MBE method on semi-insulating GaAs. The PR signal splitting of substate and epilayer was observed. The band gap energy was about 1.40 eV. It make to 8 meV difference when it is fitted by Pan's equation. The reason is stress on the interface, which is due to lattice mismatch between epilayer and substate . We became to know that reason influence crystalline on growing sample. In InGaAs epilayer, temperature dependency is low. The efficiency of photo absorption is high and activate over 200K. In this case when it is annealed at $400^{\circ}C$ below growing temperature, PR signal splitting is remarkable and crystalline is inhanced.

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A Study on Error of Frequence Rainfall Estimates Using Random Variate (무작위변량을 이용한 강우빈도분석시 내외삽오차에 관한 연구)

  • Chai, Han Kyu;Eam, Ki Ok
    • Journal of Industrial Technology
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    • v.20 no.A
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    • pp.159-167
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    • 2000
  • In the study rainfall frequency analysis attemped the many specific property data record duration it is differance from occur to error-term and probability ditribution of concern manifest. error-term analysis of method are fact sample data using method in other hand it is not appear to be fault that sample data of number to be small random variates. Therefore, day-rainfall data: to randomicity consider of this study sample data to the Monte Carlo method by randomize after data recode duration of form was choice method which compared an assumed maternal distribution from splitting frequency analysis consequence. In the conclusion, frequency analysis of chuncheon region rainfall appeared samll RMSE to the Gamma II distribution. In the rainfall frequency analysis estimate RMSE using random variates great transform, RMSE is appear that return period increasing little by little RMSE incresed and data number incresing to RMSE decreseing.

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Nonparametric Granger Causality Test

  • Jeong, Ki-ho;Nishiyama, Yoshihiko
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.1
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    • pp.195-210
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    • 2007
  • This paper develops a consistent nonparametric test for Granger causality in the context of strong-mixing process, which covers a large class of stationary processes including ARMA and ARCH models. The previously proposed tests require absolute regularity ($\beta$-mixing) more stringent than the strong-mixing condition. We prove the consistency of the test under a high level assumption on the approximation error of U statistic by its projection. Due to the sample splitting, the test statistic we propose is asymptotically normally distributed under the null.

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Automatic Tetrahedral Mesh Generation using 3-D Operators (3-D 오퍼레이터를 이용한 사면체 요소망의 자동 생성)

  • 권기연;채수원;이병채
    • Korean Journal of Computational Design and Engineering
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    • v.9 no.1
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    • pp.27-34
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    • 2004
  • A tetrahedral mesh generation scheme using 3-D operators has been presented. The proposed scheme employs new 3-D operators such as rearranging and modified finishing operators in addition to the previous trimming, wedging, digging, splitting and finishing operators. These new operators have been introduced in order to increase the stability of mesh generation process. Check processings with surrounded element edges and faces have also been optimized by employing a searching algorithm. Sample meshes are constructed to demonstrate the mesh generating capability of the proposed algorithm.

7$\AA$ Phase in the Sancheong Kaolin : 7$\AA$-Halloysite or Kaolinite\ulcorner (산청 고령토중의 7$\AA$ 상에 대한 연구 : 7$\AA$-할로이사이트 또는 캐올리나이트\ulcorner)

  • 정기영;김수진
    • Journal of the Mineralogical Society of Korea
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    • v.2 no.1
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    • pp.18-25
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    • 1989
  • The X-ray diffraction and electron microscopy study of the kaolin sample from Sancheong area show that the halloysite occurs as hydrated 10$\AA$ form. It implies that the 7$\AA$ reflection and hk-line splitting in the X-ray diffractogram are ascribed to kaolinite. Kaolinite in Sancheong kaolin is of a disordered type. It tends to be enriched in the colored part of kaolin samples. Quantitative analyses show that kaolin contains 16-57% halloysite and 10-55%kaolinite.

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Automatic Extraction of Chromosome Image Samples for the Karyotype Analysis (핵형분석을 위한 염색체 영상 표본의 자동 추출)

  • Chang, Yong-Hoon;Lee, Kwon-Soon;Jeon, Gye-Rok
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.661-663
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    • 1995
  • Chromosome analysis is an important and difficult task for clinical diagnosis for mutagen dosimetry, and for biological research. It is expensive, time consuming and imprecise when performed manually. Efforts to automate some or all of the procedures have continued for more than 30 years, with only limited success. An acquiring sample from chromosome group is not solved with automatic method. It is still performed by user. This paper represents the method of an automatic chromosome sample extraction which based on region splitting, and scan converted method.

  • PDF