• Title/Summary/Keyword: Exponential Type

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EXPONENTIAL DECAY FOR THE SOLUTION OF THE VISCOELASTIC KIRCHHOFF TYPE EQUATION WITH MEMORY CONDITION AT THE BOUNDARY

  • Kim, Daewook
    • East Asian mathematical journal
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    • v.34 no.1
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    • pp.69-84
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    • 2018
  • In this paper, we study the viscoelastic Kirchhoff type equation with a nonlinear source for each independent kernels h and g with respect to Volterra terms. Under the smallness condition with respect to Kirchhoff coefficient and the relaxation function and other assumptions, we prove the uniform decay rate of the Kirchhoff type energy.

ON THE SUPERSTABILITY OF SOME PEXIDER TYPE FUNCTIONAL EQUATION II

  • Kim, Gwang-Hui
    • The Pure and Applied Mathematics
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    • v.17 no.4
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    • pp.397-411
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    • 2010
  • In this paper, we will investigate the superstability for the sine functional equation from the following Pexider type functional equation: $f(x+y)-g(x-y)={\lambda}{\cdot}h(x)k(y)$ ${\lambda}$: constant, which can be considered an exponential type functional equation, the mixed functional equation of the trigonometric function, the mixed functional equation of the hyperbolic function, and the Jensen type equation.

A Study of Design Method of an Axial-Type Suction Fan (축류형 흡입송풍기 설계기술에 관한 연구)

  • Choi, Hyoung-Jun;Kim, Chang-Su;Cho, Chong-Hyun;Cho, Soo-Yong
    • The KSFM Journal of Fluid Machinery
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    • v.13 no.1
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    • pp.42-51
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    • 2010
  • Many different types of fan have been applying to various industrial fields. Fan design methods are much different depending on the types of fan, operating conditions, and connecting parts at the inlet or exit of the fan etc. In this study, design methods for an axial-type suction fan are studied. This fan discharges the air in the relative static pressure of -285Pa to the atmosphere with the flow rate of $960m^3/min$. For three-dimensional blade design, three different design methods were applied, such as the free vortex method, the exponential method, and the cascade method. In the cascade method, the blade loading along the radial direction was obtained from the lift coefficient which was necessary to obtain the pressure rise on a fan rotor. This method is different from the free vortex and the exponential method which control the strength of the vortex. The fan performance prediction was conducted using the CFD with three different inlet ducts. The best fan performance was obtained when the fan was designed by using the cascade method. The designed fan using the exponential method showed better performance compared to a fan designed using the free vortex method. However, the fan performance was changed depending on the installed inlet ducts. So, an efficient fan can be designed with the adjustment of design variables on the basis of the flow structures within the fan as well as the fan design procedure.

STABILITY OF TRIGONOMETRIC TYPE FUNCTIONAL EQUATIONS IN RESTRICTED DOMAINS

  • Chung, Jae-Young
    • The Pure and Applied Mathematics
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    • v.18 no.3
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    • pp.231-244
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    • 2011
  • We prove the Hyers-Ulam stability for trigonometric type functional inequalities in restricted domains with time variables. As consequences of the result we obtain asymptotic behaviors of the inequalities and stability of related functional inequalities in almost everywhere sense.

Simulation of Run-Length and Run-Sum of Daily Rainfall and Streamflow (일수문량의 RUN-LENGTH 및 RUN-SUM의 SIMULATION)

  • 이순택;지홍기
    • Water for future
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    • v.10 no.1
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    • pp.79-94
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    • 1977
  • This study is aimed at the establishment and examination of stochastic model to simulate Run-length and Run-sum of daily rainfall and streamflow. In the analysis, daily rainfall records in major cities (Seoul, Kangnung, Taegu, Kwangju, Busan, and Cheju) and daily streamflow records of Major rivers (Han, Nakdong and Geum River) were used. Also, the fitness of daily rainfall and streamflow to Weibull and one parameter exponential distribution was tested by Chi-square and Kolmogorov-Smirnov test, from which it was found that daily rainfall and streamflow generally fit well to exponential type distribution function. The Run-length and Run-sum were simulated by the Weibull Model (WBL Model), one parameter exponential model (EXP-1 Model) based on the Nonte Carlo technique. In this result, Run-length of rainfall was fitted for one parameter exponential model and Run-length of streamflow was fitted for Weibull model. And Run-sum of rainfall and streamflow were fit comparatively for regression model. Hereby, statistical charactristics of Simulation data were sinilar to historical data.

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Isolation and characterization of Vitreoscilla mutant defective in catalase-peroxidase hydroperoxidase I

  • Kim, Hee-Jung;Moon, Ja-Young;Lee, John-Hwa;Park, Kie-In
    • Korean Journal of Veterinary Service
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    • v.30 no.3
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    • pp.291-304
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    • 2007
  • Mutants of an obligate aerobic bacterium, Vitreoscilla, that have deficiency in heat-labile catalase-peroxidase hydroperoxidase I (HPI) were created by EMS treatment. The catalase-peroxidase HPI-deficient mutant showed substantially lower peroxidase activity in exponential and mid-stationary phase compared with the wild type strain. In late stationary phase, the mutant exhibited no peroxidase activity. Peroxidase deficiency in the mutant was revealed by polyacrylamide gels stained for peroxidase activity. Characteristically, catalase levels in the mutant increased about 14- and 8-fold during growth in the exponential and stationary phases, respectively, compared to those in the wild type, suggesting a compensatory effect for protection from $H_2O_2$ toxicity. The mutant showed differences in physiology from the wild type: retardation in growth rate and decrease in oxygen consumption. Both the wild type and the catalase-peroxidase HPI-deficient mutant of Vitreoscilla had lower growth rates in media containing increasing $H_2O_2$ concentrations. However, the mutant exhibited an additionally decreased growth rate after 6 to 8 h of growth compared to the wild type. The wild type was resistent up to 20 mM $H_2O_2$, whereas the mutant was very sensitive to high concentrations of exogenous $H_2O_2$. Although elevated catalase levels would provide protection of the bacteria from the deleterious effect of $H_2O_2$, it did not appear to be complete. Cell-free extracts of the mutant showed decreased NADH oxidation rates and higher accumulation of $H_2O_2$ during this oxidation. These results may account for the impaired growth and earlier onset of death phase by the catalase-peroxidase HPI-deficient mutant of Vitreoscilla.

A study on the in-service teacher's recognition and fallacy for irrational exponent (무리지수에 대한 교사들의 인식과 오류)

  • Lee, Heon Soo;Kim, Young Cheol;Park, Yeong Yong
    • Journal of the Korean School Mathematics Society
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    • v.16 no.3
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    • pp.583-600
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    • 2013
  • In this paper, we study the recognition and fallacy of would-be in-service teachers about numbers with irrational exponent. We chose 51 secondary school teachers who are teaching mathematics in K metropolitan city and investigate their recognition and fallacy about the cases of irrational exponents of a positive rational and irrational exponents of a positive irrational number at the expansion of exponential law. We found following facts. First, in-service teacher's a percentage of correct answers differ depending on the type of numbers with irrational exponent. Second, in-service teachers decide their answer depending on intuition rather than logic. Third, in-service teachers decide their answer depending on exponential rather than base.

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Valuation of Han River Waterside Landscape with a Double-bound Dichotomous Choice Model and Policy Implications: Focused on the Exponential Willingness to Pay Model (이중양분선택법에 의한 한강 수변 경관의 가치 추정과 그 시사점 -지수지불의사 모형을 중심으로-)

  • Han, Taek-Whan;Hong, Yiseok;Park, Chang Sug
    • Environmental and Resource Economics Review
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    • v.22 no.1
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    • pp.179-214
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    • 2013
  • This paper estimated the value of waterside landscape and ecosystem of Han River basin with a double-bound dichotomous choice type of CVM. We used the exponential willingness to pay model to represent the nonnegative willingness to pay. This model is found to be especially important in analyzing a double-bound dichotomous choice model. The total willingness to pay was estimated as 705.5 billion won per annum. This suggests that current budget size for water quality and ecosystem conservation for Han River needs to be expanded.