• Title/Summary/Keyword: Fucntion

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THE LAW OF A STOCHASTIC INTEGRAL WITH TWO INDEPENDENT BIFRACTIONAL BROWNIAN MOTIONS

  • Liu, Junfeng
    • Communications of the Korean Mathematical Society
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    • v.26 no.4
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    • pp.669-684
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    • 2011
  • In this note, we obtain the expression of the characteristic fucntion of the random variable $\int_o^TB_s^{{\alpha},{\beta}}dB_s^{H,K}$, where $B^{{\alpha},{\beta}}$ and $B^{H,K}$ are two independent bifractional Brownian motions with indices ${\alpha}{\in}(0,1),{\beta}{\in}(0, 1]$ and $HK{\in}(\frac{1}{2},\;1)$ respectively.

A UNITARY LINEAR SYSTEM ON THE BIDISK

  • Yang, Meehyea;Hong, Bum-Il
    • Honam Mathematical Journal
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    • v.29 no.4
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    • pp.511-521
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    • 2007
  • Let S($z_1$, $z_2$) be a power series with operator coefficients such that multiplication by 5($z_1$, $z_2$) is a contractive transformation in the Hilbert space $\mathbf{H}_2$($\mathbb{D}^2$, C). In this paper we show that there exists a Hilbert space D($\mathbb{D}$,$\bar{S}$) which is the state space of extended canonical linear system with a transfer fucntion $\bar{S}$(z).

Prediction of Powertrain Structure-borne Noise Using Hybrid Model (하이브리드 모델을 이용한 파워트레인 가진에 의한 구조 기인 소음 예측)

  • Lee, Sang-Kwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.12-22
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    • 2007
  • This paper presents to predict the powertrain structure-borne noise which is primary resource of interior noise. As the first step, it is built up a hybrid powertrain model which is based on the real powertrain which is verified with static and dynamic properties. The methods for verifying are modal analysis and running vibration testing which are experimentally implemented. Based on the Hybrid powertrain component model, an initial predictive assembly model is simulated. As the second step, the characteristic transfer functions are measured that are dynamic stiffness of rubber mounts and vibro-acoustic transfer function based on the acoustic reciprocity. Several techniques utilizing special experimental devices have been proposed for this research. Finally, the structure-borne noise by powertrain will be predict and verify with dynamic simulation and experiment.

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Influential Factors on Depression among Male and Female High School Students (남녀 고등학생의 우울관련 요인)

  • Choi, Mi-Kyoung
    • The Journal of Korean Society for School & Community Health Education
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    • v.14 no.3
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    • pp.51-65
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    • 2013
  • Objectives: The main purpose of this study was to compare influencing factors on depression between male and female students at the high school. Methods: The self-administered questionnaire survey was carried out on a convenience sample of 403 high school students. The data analysis procedure included frequency, ${\chi}^2$ test, t-test, ANOVA, Pearson correlation coefficients, and stepwise multiple regression using depression as the dependent variable. Results: There was a significant gender difference in depressive symptoms; the mean depression score of female students was higher than that of male students. Stepwise multiple regression analysis for depression revealed that the most powerful predictors (34%) were powerlessness and self-esteem for male students. On the other hand, the factors such as self-esteem, mother's occupation, and family fucntion were the most significant predictors (50%) for female students. Conclusion: The necessity of an intervention considering gender difference in high school students so as to prevent the occurrence of depression was suggested.

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Evaluation of flutter derivatives for time domain analysis with optimization (시간 영역 해석을 위한 플러터 계수의 최적화 결정법)

  • Jung, Kil-Je;Lee, Hae-Sung;Kim, Ho-Kyung
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2011.04a
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    • pp.88-89
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    • 2011
  • 풍하중이 작용하는 교량의 응답을 구하기 위하여 RFA(Rational Function Approximation)와 같은 시간 영역해석법이 널리 사용되고 있다. 교량 단면의 공기역학적 특성을 정의하는 플러터 계수는 주파수 영역에서 정의되기 때문에, 시간 영역해석을 위하여 inverse Fourier transform을 통해 얻어진 impulse response function을 이용한 중첩 적분법이 제안되었다. 시간 영역해석을 위해서는 플러터 계수에 상관성이 존재해야 함을 밝히고, 최적화 방법을 이용하여 시간 영역 해석을 위한 플러터 계수 산정법을 제안하고자 한다. B/D=20의 구형 단면에 적용하여 제안한 방법의 타당성을 검증하고자 한다.

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The Dielectric and Piezoelectric Characteristics of PMN- PSN-Pfl Ceramic as a Fucntion of Glass Frit (Glass Frit 첨가량에 따른 PMN-PSN-PZT계 세라믹의 유전 및 압전특성)

  • 김성진;류주현;이수호;홍재일;윤현상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.256-259
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    • 1999
  • The purpose of this study is to develop the material for multiayer piezoelectric ceramic transformer because multiayer piezoelectric transformer must need low sintering temperature. So that PMN-PSN-PZT family ceramics were added with glass brit(SiO$_2$ $.$ PbO). The dielectric and piezoelectric properties were increased with increasing it until the amounts of additive 0.8wt%. Sintering temperature were low about 100[$^{\circ}C$]. Accordingly, This material could be used to multiayer piezoelectric transformer .

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Effects of Dietary Fiber Sourecs on Lipid Metabolism and Kidney Function in Rats Fed High Cholesterol Diet (식이섬유 종류가 고콜레스테롤 식이를 급여한 흰쥐의 체내 지질대사 및 신장기능에 미치는 영향)

  • 박영주;박양자;김민선
    • Journal of the East Asian Society of Dietary Life
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    • v.8 no.2
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    • pp.107-115
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    • 1998
  • This study was conducted to investigate the effects of dietary fibers (cellulose ; polydextrose ; pectin ; ricebran) supplementation on the kidney fucntion of hyperlipidemic-induced rats on a high cholesterol diet (5% cholesterol). Serum lipid concentrations were not influenced by dietary fiber sources, but the pectin group was effective in reducing serum lipid levels. Total serum protein and albumin concentrations tended to higher in the polydextrose group, and serum creatinine and urea-N concentrations were higher in the pectin group than those in the other groups. Even though total urinary protein was high in the pectin group, GFR was reduced (18~30% decrease) as compared to other groups. The urea-N level was elevated in the polydextrose group as compared to that of cellulose group(25% increase). Total lipid, triglyceride and cholesterol concentrations in the liver of pectin group were lower than those of other groups. Total lipid and cholesterol concentrations in the kidneys were reduced in pectin and ricebran groups, respectively. The total cholesterol concentration infecal was significantly high in the polydextrose and pectin groups(p<0.05), and the triglyceride was highest in the pectin group. These results indicate no significant effects of dietary fiber supplementation on the kidney function of hyperlipidemic-induced rats on a high cholesterol diet, but pectin was very effective to improve lipid metabolism and to reduce GFR.

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Design of flow control fucntion for ABR service in ATM networks (ATM 망에서 ABR 서비스 제공을 위한 흐름 제어 기능 설계)

  • Kang, Hun;Lee, Soong-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.5
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    • pp.1208-1221
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    • 1998
  • We survey several issues for implementing the end-to-end flow control function for ABR service and propose a structure for implementation. In the proposed design, control parameters are calculated and maneuvered by software for easy implementation and efficiency adaptbility for the changes of parameters while the cells are emitted at the rate according to the allowed cell rate with the hardware implementation for real time processing. The proposed structure can cope with the changes of the specifications including the calculation of the control parameters and their application. Hence, the structure is expected to contribute to providing the ABR serice in the future ATM networks.

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Marriage, Sex Role, and Mortality : A Comparison Between Korea and the United States (결혼, 성역할 및 사망력 : 한.미 비교연구)

  • 박경애
    • Journal of Families and Better Life
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    • v.10 no.2
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    • pp.51-59
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    • 1992
  • Previous studies indicated that unmarried persons are subject to higher mortality than the married, and that the differentials are more marked for male than for females. There are two major approaches to explaining the marital status differentials in mortality ; selection function and protection function of marriage. Following protection fucntion, this study develops the new "instrumental / expressive sex-role" hypothesis in order to explain why marriage protects males more against death. The hypothesis expects that male's instrumental role and female's expressive role have direct effect as well as indirect effect through social integration on sex differential mortality by marital status. for the hypothesis testing, Korea and US vital statistics and census data are used to compute age-specific , age-adjusted mortality rates and their ratios for persons in different marital status. Major findings are as follows. 1)For both Korea and US being married is more advantageous to males than females, ad being widowed, divorced, and separated is more disadvantageous to males, while being never-married is more disadvantageous to females, 2) For Korea, the never married men and women have the highest mortality rates, 3) For US the never married women have the highest mortality rate, while the divorced, separated, and widowed men have the highest mortality rate. Fro both Korea and US data, selection function is rejected, but instrumental/expressive sex-role hypothesis succeeds in accounting for the sex and marital status differential in mortality.

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