• Title, Summary, Keyword: semi-convergence

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SEMI-CONVERGENCE OF p-STACKS

  • Min, Won-Keun
    • Communications of the Korean Mathematical Society
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    • v.18 no.3
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    • pp.533-540
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    • 2003
  • We introduce the notion of semi-convergence of p-stacks and by using that notion we characterize the semi-interior, semiclosure, separation axioms and semi-continuity on a topological space. Also we introduce a new notion of p-somicompactness and investigate its properties in terms of semi-convergence of p-stacks.

SEMI-CONVERGENCE OF THE PARAMETERIZED INEXACT UZAWA METHOD FOR SINGULAR SADDLE POINT PROBLEMS

  • YUN, JAE HEON
    • Bulletin of the Korean Mathematical Society
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    • v.52 no.5
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    • pp.1669-1681
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    • 2015
  • In this paper, we provide semi-convergence results of the parameterized inexact Uzawa method with singular preconditioners for solving singular saddle point problems. We also provide numerical experiments to examine the effectiveness of the parameterized inexact Uzawa method with singular preconditioners.

ACCELERATION OF ONE-PARAMETER RELAXATION METHODS FOR SINGULAR SADDLE POINT PROBLEMS

  • Yun, Jae Heon
    • Journal of the Korean Mathematical Society
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    • v.53 no.3
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    • pp.691-707
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    • 2016
  • In this paper, we first introduce two one-parameter relaxation (OPR) iterative methods for solving singular saddle point problems whose semi-convergence rate can be accelerated by using scaled preconditioners. Next we present formulas for finding their optimal parameters which yield the best semi-convergence rate. Lastly, numerical experiments are provided to examine the efficiency of the OPR methods with scaled preconditioners by comparing their performance with the parameterized Uzawa method with optimal parameters.

Simulation and Fabrication Studies of Semi-superjunction Trench Power MOSFETs by RSO Process with Silicon Nitride Layer

  • Na, Kyoung Il;Kim, Sang Gi;Koo, Jin Gun;Kim, Jong Dae;Yang, Yil Suk;Lee, Jin Ho
    • ETRI Journal
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    • v.34 no.6
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    • pp.962-965
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    • 2012
  • In this letter, we propose a new RESURF stepped oxide (RSO) process to make a semi-superjunction (semi-SJ) trench double-diffused MOSFET (TDMOS). In this new process, the thick single insulation layer ($SiO_2$) of a conventional device is replaced by a multilayered insulator ($SiO_2/SiN_x/TEOS$) to improve the process and electrical properties. To compare the electrical properties of the conventional RSO TDMOS to those of the proposed TDMOS, that is, the nitride_RSO TDMOS, simulation studies are performed using a TCAD simulator. The nitride_RSO TDMOS has superior properties compared to those of the RSO TDMOS, in terms of drain current and on-resistance, owing to a high nitride permittivity. Moreover, variations in the electrical properties of the nitride_RSO TDMOS are investigated using various devices, pitch sizes, and thicknesses of the insulator. Along with an increase of the device pitch size and the thickness of the insulator, the breakdown voltage slowly improves due to a vertical field plate effect; however, the drain current and on-resistance degenerate, owing to a shrinking of the drift width. The nitride_RSO TDMOS is successfully fabricated, and the blocking voltage and specific on-resistance are 108 V and $1.1m{\Omega}cm^2$, respectively.

Development of Image Analysis Program for Microstructure in Semi-solid Forming Product (반용융 성형 제품의 미세조직 영상분석을 위한 프로그램 개발)

  • Kwon, Soon-Goo;Park, Joon-Hong
    • Journal of the Korean Society of Industry Convergence
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    • v.4 no.1
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    • pp.3-9
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    • 2001
  • Many products related to automobile and airplane have been manufactured by semi-solid process. There are many parameters in semi-solid process such as punch velocity, die temperature, and solid fraction of material. Among these parameters, solid fraction of material is one of the most important factors to determine quality of product. To obtain solid fraction of a certain semi-solid product is very necessary and useful for inspecting and analyzing the product. In this paper, image analysis program for microstructure by semi-solid forming process has been developed with the simple apparatus such as a personal computer and scanner, instead of expensive image analyzer.

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A Design of Managerial Accounting Information Characteristics considered the Organizational Culture

  • Kim, Kyung-Ihl
    • Journal of Convergence Society for SMB
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    • v.4 no.4
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    • pp.7-12
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    • 2014
  • This study empirically investigated cultural differences in the amount of information provided by managerial accounting information systems as well as the differences in organizational performance according to variations in the amount of information. Through cluster analysis, I classified sample firms into five organizational cultural types: Semi-innovative, innovative, bureaucratic, semi-bureaucratic and supportive. The results showed that in the semi-innovative firms, a greater amount of the traditional and advanced types of information is produced, while in bureaucratic firms, traditional information is much more provided than in the innovative, semi-bureaucratic and supportive firms. These results confirmed cultural differences in the amount of information produced. According to the results of this study, it was found that in organizational performance, the rankings of semi-innovative firms, which have the highest scores in the amount of information, are also the highest, and the performance scores in innovative firms are generally next to those of semi-innovative firms. Hence it is concluded that there are cultural differences in the amount of information provided and theses differences affect organizational performance

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ON ALMOST SURE CONVERGENCE OF NEGATIVELY SUPERADDITIVE DEPENDENT FOR SEMI-GAUSSIAN RANDOM VARIABLES

  • BAEK, JONG-IL;SEO, HYE-YOUNG
    • Journal of applied mathematics & informatics
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    • v.39 no.1_2
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    • pp.145-153
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    • 2021
  • When {Xni|1 ≤ i ≤ n, n ≥ 1} be an array of rowwise negatively superadditive dependent(NSD) for semi-Gaussian random variables and {ani|1 ≤ i ≤ n, n ≥ 1} is an array of constants, we study the almost sure convergence of weighted sums ∑ni=1 aniXni under some appropriate conditions and we obtain some corollaries.

Study on semi-supervised local constant regression estimation

  • Seok, Kyung-Ha
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.3
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    • pp.579-585
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    • 2012
  • Many different semi-supervised learning algorithms have been proposed for use wit unlabeled data. However, most of them focus on classification problems. In this paper we propose a semi-supervised regression algorithm called the semi-supervised local constant estimator (SSLCE), based on the local constant estimator (LCE), and reveal the asymptotic properties of SSLCE. We also show that the SSLCE has a faster convergence rate than that of the LCE when a well chosen weighting factor is employed. Our experiment with synthetic data shows that the SSLCE can improve performance with unlabeled data, and we recommend its use with the proper size of unlabeled data.

Quality of Radiomic Features in Glioblastoma Multiforme: Impact of Semi-Automated Tumor Segmentation Software

  • Lee, Myungeun;Woo, Boyeong;Kuo, Michael D.;Jamshidi, Neema;Kim, Jong Hyo
    • Korean Journal of Radiology
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    • v.18 no.3
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    • pp.498-509
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    • 2017
  • Objective: The purpose of this study was to evaluate the reliability and quality of radiomic features in glioblastoma multiforme (GBM) derived from tumor volumes obtained with semi-automated tumor segmentation software. Materials and Methods: MR images of 45 GBM patients (29 males, 16 females) were downloaded from The Cancer Imaging Archive, in which post-contrast T1-weighted imaging and fluid-attenuated inversion recovery MR sequences were used. Two raters independently segmented the tumors using two semi-automated segmentation tools (TumorPrism3D and 3D Slicer). Regions of interest corresponding to contrast-enhancing lesion, necrotic portions, and non-enhancing T2 high signal intensity component were segmented for each tumor. A total of 180 imaging features were extracted, and their quality was evaluated in terms of stability, normalized dynamic range (NDR), and redundancy, using intra-class correlation coefficients, cluster consensus, and Rand Statistic. Results: Our study results showed that most of the radiomic features in GBM were highly stable. Over 90% of 180 features showed good stability (intra-class correlation coefficient [ICC] ${\geq}0.8$), whereas only 7 features were of poor stability (ICC < 0.5). Most first order statistics and morphometric features showed moderate-to-high NDR (4 > NDR ${\geq}1$), while above 35% of the texture features showed poor NDR (< 1). Features were shown to cluster into only 5 groups, indicating that they were highly redundant. Conclusion: The use of semi-automated software tools provided sufficiently reliable tumor segmentation and feature stability; thus helping to overcome the inherent inter-rater and intra-rater variability of user intervention. However, certain aspects of feature quality, including NDR and redundancy, need to be assessed for determination of representative signature features before further development of radiomics.

A MODIFIED INEXACT NEWTON METHOD

  • Huang, Pengzhan;Abduwali, Abdurishit
    • Journal of applied mathematics & informatics
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    • v.33 no.1_2
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    • pp.127-143
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    • 2015
  • In this paper, we consider a modified inexact Newton method for solving a nonlinear system F(x) = 0 where $F(x):R^n{\rightarrow}R^n$. The basic idea is to accelerate convergence. A semi-local convergence theorem for the modified inexact Newton method is established and an affine invariant version is also given. Moreover, we test three numerical examples which show that the modified inexact scheme is more efficient than the classical inexact Newton strategy.