• 제목/요약/키워드: large solutions

검색결과 1,277건 처리시간 0.045초

THE FRACTIONAL SCHRÖDINGER-POISSON SYSTEMS WITH INFINITELY MANY SOLUTIONS

  • Jin, Tiankun;Yang, Zhipeng
    • 대한수학회지
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    • 제57권2호
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    • pp.489-506
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    • 2020
  • In this paper, we study the existence of infinitely many large energy solutions for the supercubic fractional Schrödinger-Poisson systems. We consider different superlinear growth assumptions on the non-linearity, starting from the well-know Ambrosetti-Rabinowitz type condition. We obtain three different existence results in this setting by using the Fountain Theorem, all these results extend some results for semelinear Schrödinger-Poisson systems to the nonlocal fractional setting.

Selection Problems in terms of Coefficients of Vairiation

  • Park, Chi-Hoon;Jeon, Jong-Woo;Kim, Woo-Chul
    • Journal of the Korean Statistical Society
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    • 제11권1호
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    • pp.12-24
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    • 1982
  • Selection procedures are proposed for selecting the 'best' industrial process with the smallest fraction defective. For normally distributed industrial processes, this is equivalent to selecting in terms of coefficients of variation. For the case of known vairances, selection procedures by Bechhofer (1954), and Bechhofer and Turnball (1978) are appropriate. We treat this problem for the case of uknown variances with or without reference to a standard. The large sample solutions of design constants are tabulated and the performance of these approximate solutions are investigated.

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Securing Web Services: Existing Solutions and Their Limitations

  • Nasridinov, Aziz;Byun, Jeong-Yong;Park, Young-Ho
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2012년도 추계학술발표대회
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    • pp.918-919
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    • 2012
  • Web Services have been used in a variety of applications and have become a key technology in developing business operations on the Web. However, despite the growing use of Web Services by large corporations, security is still a major concern that is slowing their deployment. In this paper, we give an overview of security vulnerabilities, review the existing solutions, and show their limitations.

지지점 가속도에 의해 가진되는 보의 응력계산에 대한 거대질량법의 정확도 (Numerical Tests of Large Mass Method for Stress Calculation of Euler-Bernoulli Beams Subjected to Support Accelerations)

  • 김용우;최남석;정명조
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2013년도 춘계학술대회 논문집
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    • pp.188-193
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    • 2013
  • The large mass method for dynamic analysis of statically determinate beams subjected to in-phase support motions is justified by showing that the equation of motion of the beams under consideration is equivalent to that of large mass model of the beam when an appropriate large mass ratio is employed. The accuracy of the stress responses based on the beam large mass method is investigated through careful numerical tests. The numerical results are compared to analytic solutions and the comparison shows that the large mass method yields not only the time history of motion but also the distributions of bending moment and shear force accurately.

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ASYMPTOTIC STABILITY OF COMPETING SPECIES

  • Kim, June Gi
    • Korean Journal of Mathematics
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    • 제4권1호
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    • pp.39-43
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    • 1996
  • Large-time asymptotic behavior of the solutions of interacting population reaction-diffusion systems are considered. Polynomial stability was proved.

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Rheology of concentrated xanthan gum solutions: Oscillatory shear flow behavior

  • Song Ki-Won;Kuk Hoa-Youn;Chang Gap-Shik
    • Korea-Australia Rheology Journal
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    • 제18권2호
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    • pp.67-81
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    • 2006
  • Using a strain-controlled rheometer, the dynamic viscoelastic properties of aqueous xanthan gum solutions with different concentrations were measured over a wide range of strain amplitudes and then the linear viscoelastic behavior in small amplitude oscillatory shear flow fields was investigated over a broad range of angular frequencies. In this article, both the strain amplitude and concentration dependencies of dynamic viscoelastic behavior were reported at full length from the experimental data obtained from strain-sweep tests. In addition, the linear viscoelastic behavior was explained in detail and the effects of angular frequency and concentration on this behavior were discussed using the well-known power-law type equations. Finally, a fractional derivative model originally developed by Ma and Barbosa-Canovas (1996) was employed to make a quantitative description of a linear viscoelastic behavior and then the applicability of this model was examined with a brief comment on its limitations. Main findings obtained from this study can be summarized as follows: (1) At strain amplitude range larger than 10%, the storage modulus shows a nonlinear strain-thinning behavior, indicating a decrease in storage modulus as an increase in strain amplitude. (2) At strain amplitude range larger than 80%, the loss modulus exhibits an exceptional nonlinear strain-overshoot behavior, indicating that the loss modulus is first increased up to a certain strain amplitude(${\gamma}_0{\approx}150%$) beyond which followed by a decrease in loss modulus with an increase in strain amplitude. (3) At sufficiently large strain amplitude range (${\gamma}_0>200%$), a viscous behavior becomes superior to an elastic behavior. (4) An ability to flow without fracture at large strain amplitudes is one of the most important differences between typical strong gel systems and concentrated xanthan gum solutions. (5) The linear viscoelastic behavior of concentrated xanthan gum solutions is dominated by an elastic nature rather than a viscous nature and a gel-like structure is present in these systems. (6) As the polymer concentration is increased, xanthan gum solutions become more elastic and can be characterized by a slower relaxation mechanism. (7) Concentrated xanthan gum solutions do not form a chemically cross-linked stable (strong) gel but exhibit a weak gel-like behavior. (8) A fractional derivative model may be an attractive means for predicting a linear viscoelastic behavior of concentrated xanthan gum solutions but classified as a semi-empirical relationship because there exists no real physical meaning for the model parameters.

연근해주요어업의 성장성분석(II) (An Analysis of the Growing Trend on the Major Fisheries of the Coastal and Adjacent-Sea in Korea)

  • 김태용
    • 수산경영론집
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    • 제13권1호
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    • pp.63-84
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    • 1982
  • This study is an analysis of the growing trend from 1971 to 1980 on the four major fisheries in Korea; large powered purse seine, anchovy drag net, two boats large trawl and one boat large trawl. The main purpose of this study is to find some solutions against the problems which these fisheries are faced with, through the analysis of the growing trend of income, capital structure and main ratios of finance. According to the result of the analysis, the problems are as following: \circled1 Revenues per vessel was decreased when catches per vessel was decreased in 1979, 1980. therefore the increase ratio of the revenues per vessel was weakened from 1979. \circled2 Catches per vessel was decreased from 1979 in spite of the increase of gross cathes in its field. \circled3 Production costs in fishing, such as the cost of wages, fuels and repairs, was steadily up year by year. \circled4 Profitability was deteriorated from 1978. \circled5 productivity was lower from 1978. \circled6 Stability was lower from 1978. The solutions out of the above problems are as follows; \circled1 Fisheries resources must be fostered. \circled2 The numbers of vessels should be reduced according to the fisheries resources. \circled3 The precise amount of resources should be dynamically estimated. \circled4 The fishermen must be educated to reduce fishing cost such as the cost of fuels and repairs, etc. \circled5 The old vessels should be replaced. \circled6 The production efficiency should be promoted. \circled7 The rate of interest should be cut down to reduce financial cost.

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제어기의 이득 섭동을 갖는 이산 시간지연 대규모 시스템을 위한 강인 비약성 제어기 (Decentralized Stabilization for Uncertain Discrete-Time Large-Scale Systems with Delays in Interconnections and Controller Gain Perturbations)

  • 박주현
    • 전자공학회논문지SC
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    • 제39권5호
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    • pp.8-17
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    • 2002
  • 본 논문에서는, 섭동과 제어기 이득 섭동을 갖는 이산 대규모 시간지연 시스템의 강인 비약성 제어기 설계에 관하여 논한다. 리아프보프 해석법을 의거하여 선형행렬 부등식으로 표현되는 주어진 시스템의 강인 안정화를 꾀하는 상태 궤환 제어기의 존재를 보장하는 조건 식을 구한다. 이 조건 식의 해로부터 각 부 시스템에서의 제어기의 이득 및 제어기의 비약성 지수도 얻을 수 있다. 제시된 선형행렬 부등식은 잘 알려진 최적화 기법으로 쉽게 풀 수 있으며, 예제를 통하여 제어기 설계 방법을 보인다.

대규모 해상풍력발전단지 운용을 위한 SCADA 시스템 설계 (Design of SCADA System for a Large-Scale Offshore Wind Farm)

  • 김동욱;송재주;정남준;최효열
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
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    • 제1권3호
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    • pp.161-170
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    • 2012
  • 전 세계적으로 신재생에너지에 대한 관심이 고조되고 있다. 특히 풍력은 높은 경제성으로 인하여 연구개발이 활발히 진행되고 있다. 국내에 서도 서남해 지역에 대규모 해상 풍력발전단지 연구개발을 진행중에 있다. 현재 풍력발전단지 운영을 위한 SCADA 시스템의 국내 기술 수준은 매우 낮은 수준으로 대규모 발전단지에 적용이 가능한 SCADA 시스템 개발이 시급한 실정이다. 따라서 본 논문에서는 대규모 해상풍력발전단지 SCADA 시스템 개발을 위해서 필요한 고려 사항과 이를 바탕으로 SCADA 시스템 설계 내용을 기술하였다.