• Title/Summary/Keyword: triple positive solutions

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TRIPLE POSITIVE SOLUTIONS OF SECOND ORDER SINGULAR NONLINEAR THREE-POINT BOUNDARY VALUE PROBLEMS

  • Sun, Yan
    • Journal of applied mathematics & informatics
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    • v.28 no.3_4
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    • pp.763-772
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    • 2010
  • This paper deals with the existence of triple positive solutions for the nonlinear second-order three-point boundary value problem z"(t)+a(t)f(t, z(t), z'(t))=0, t $\in$ (0, 1), $z(0)={\nu}z(1)\;{\geq}\;0$, $z'(\eta)=0$, where 0 < $\nu$ < 1, 0 < $\eta$ < 1 are constants. f : [0, 1] $\times$ [0, $+{\infty}$) $\times$ R $\rightarrow$ [0, $+{\infty}$) and a : (0, 1) $\rightarrow$ [0, $+{\infty}$) are continuous. First, Green's function for the associated linear boundary value problem is constructed, and then, by means of a fixed point theorem due to Avery and Peterson, sufficient conditions are obtained that guarantee the existence of triple positive solutions to the boundary value problem. The interesting point is that the nonlinear term f is involved with the first-order derivative explicitly.

EXISTENCE OF TRIPLE POSITIVE SOLUTIONS OF A KIND OF SECOND-ORDER FOUR-POINT BVP

  • Zhao, Junfang;Ge, Weigao
    • Journal of applied mathematics & informatics
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    • v.27 no.1_2
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    • pp.183-194
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    • 2009
  • In this paper, we considered the following four-point boundary value problem $\{{x"(t)+h(t)f(t,x(t),x'(t))=0,\;0<t<1\atop%20x'(0)=ax(\xi),\;x'(1)=bx(\eta)}\$. where $0\;<\;{\xi}\;<\;{\eta}\;<\;1,\;{\delta}\;=\;ab{\xi}\;-\;ab{\eta}\;+\;a\;-\;b\;<\;0,\;0\;<\;a\;<\;\frac{1}{\xi},\;0\;<\;b\;<\;\frac{1}{\eta}$. After the discussion of the Green function of the corresponding homogeneous system, we establish some criteria for the existence of positive solutions by using the generalized Leggett-William's fixed point theorem. The interesting point is the expression of the Green function, which is a difficulty for multi-point BVP.

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Small-business Counseling: Impact for Applying Triple Helix (소상공인 경영 컨설팅: 트리플 힐릭스 적용의 효과)

  • Kim, Taekyung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.11 no.2
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    • pp.183-195
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    • 2016
  • Although we have faced substantial public interests on the issues of small-business, the lack of effective solutions corresponding to them should be worried. This paper introduces findings from the application of Triple Helix to counseling activities for small-business stores with diagnosing problems and suggesting alternatives. The findings of this paper are based on counseling projects conducted by Gyunggi Small-medium Business Corporation, universities in the region, and multiple small-business stores together from June to November in 2015. The application of Triple Helix was positive for increasing the effectiveness of counseling, and this key finding was obtained from action research cycles. It was also confirmed that cooperation from three different entities including company, university and government institute was beneficial in increasing problem identification capabilities by students and providing opportunities for testing knowledge and skills, which means Triple Helix application to small-business helps management education to be more practical. Contributions of this study supplies substantial insights to academic audience, and practitioners can learn positive effects of Triple Helix and potential issues for implementation in the context of small-business counseling.

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TRIPLE SOLUTIONS FOR THREE-ORDER PERIODIC BOUNDARY VALUE PROBLEMS WITH SIGN CHANGING NONLINEARITY

  • Tan, Huixuan;Feng, Hanying;Feng, Xingfang;Du, Yatao
    • Journal of applied mathematics & informatics
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    • v.32 no.1_2
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    • pp.75-82
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    • 2014
  • In this paper, we consider the periodic boundary value problem with sign changing nonlinearity $$u^{{\prime}{\prime}{\prime}}+{\rho}^3u=f(t,u),\;t{\in}[0,2{\pi}]$$, subject to the boundary value conditions: $$u^{(i)}(0)=u^{(i)}(2{\pi}),\;i=0,1,2$$, where ${\rho}{\in}(o,{\frac{1}{\sqrt{3}}})$ is a positive constant and f(t, u) is a continuous function. Using Leggett-Williams fixed point theorem, we provide sufficient conditions for the existence of at least three positive solutions to the above boundary value problem. The interesting point is the nonlinear term f may change sign.

Rapid Determination of Imatinib in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry: Application to a Pharmacokinetic Study

  • Yang, Jeong Soo;Cho, Eun Gi;Huh, Wooseong;Ko, Jae-Wook;Jung, Jin Ah;Lee, Soo-Youn
    • Bulletin of the Korean Chemical Society
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    • v.34 no.8
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    • pp.2425-2430
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    • 2013
  • A simple, fast and robust analytical method was developed to determine imatinib in human plasma using liquid chromatography-tandem mass spectrometry with electrospray ionization in the positive ion mode. Imatinib and labeled internal standard were extracted from plasma with a simple protein precipitation. The chromatographic separation was performed using an isocratic elution of mobile phase involving 5.0 mM ammonium formate in water-5.0 mM ammonium formate in methanol (30:70, v/v) over 3.0 min on reversed-stationary phase. The detection was performed using a triple-quadrupole tandem mass spectrometer in multiple-reaction monitoring mode. The developed method was validated with lower limit of quantification of 10 ng/mL. The calibration curve was linear over 10-2000 ng/mL ($R^2$ > 0.99). The method validation parameters met the acceptance criteria. The spiked samples and standard solutions were stable under conditions for storage and handling. The reliable method was successfully applied to real sample analyses and thus a pharmacokinetic study in 27 healthy Korean male volunteers.

Antibacterial Efficacies of Disinfectants against Salmonella typhimurium Depending on Pre-warming Conditions

  • Lee, Jin-Ju;Kim, Dong-Hyeok;Kim, Dae-Geun;Simborio, Hannah Leah;Min, Won-Gi;Lee, Hu-Jang;Chang, Dong-Il;Chang, Hong-Hee;Kim, Suk
    • Journal of agriculture & life science
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    • v.46 no.5
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    • pp.65-72
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    • 2012
  • Salmonellosis is a widespread bacterial zoonosis that commonly causes enterocolitis and foodborne poisoning leading to an extensive economic loss in domestic animal industry. Considerably, the emergence of multidrug resistant strains of Salmonella spp. induces further severe problems affecting public health. The present report was designated to investigate the antibacterial efficacies of three common disinfectants including an oxidizing compound disinfectant (OXC), a triple salt (TS) and a quaternary ammonium compound (QAC) against Salmonella typhimurium subjected to the preliminary changes of drug temperature. All solutions of three disinfectants were pre-incubated at different temperature (22, 37 and $63^{\circ}C$) for 1 h prior to exposure to bacteria. The disinfectants and bacteria were diluted with distilled water (DW), hard water (HW) or organic matter suspension (OMS) according to treatment condition. Under the DW condition, the disinfectant efficacy of the QAC at $63^{\circ}C$ was higher than that of $22^{\circ}C$. Furthermore, under HW diluent the disinfectant efficacy of the TS pre-warmed at both of 37 and $63^{\circ}C$ were increased compared to that of $22^{\circ}C$. Considerably, the efficacy of pre-warmed QAC at both of 37 and $63^{\circ}C$ under the OMS diluent were higher than that of $22^{\circ}C$. Conclusively, prewarming at higher temperatures have positive effects on the stability of the antibacterial efficacies of TS and QAC.