• 제목/요약/키워드: Positive solutions

검색결과 747건 처리시간 0.032초

상태지연 선형시스템에 대한 출력되먹임 $H^\infty$ 제어기 설계 (Output feedback $H^\infty$ controller design for linear systems with delayed state)

  • 정은태;오도창;박홍배
    • 제어로봇시스템학회논문지
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    • 제3권2호
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    • pp.109-114
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    • 1997
  • In this paper, we present an output feedback $H^\infty$controller design method and derive the sufficient condition of the bounded real lemma for linear systems with multiple delays in states. For state delayed systems, sufficient conditions for the existence $\kappa$-th order $H^\infty$controllers are given in terms of three linear matrix inequalities(LMIs). Furthermore, we show how to construct such controllers from the positive definite solutions of their LMIs and given an example to illustrate the validitiy of the proosed design procedure.

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Business Issues in Enterprise Resource Planning (ERP) Implementation

  • Raj, John Rudolph;Seetharaman, A.
    • 동아시아경상학회지
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    • 제2권4호
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    • pp.9-25
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    • 2014
  • The successful implementation of various Enterprise Resource Planning (ERP) systems has provoked considerable interest in this subject over the last few years. The senior management, especially in large corporations have been attracted to look at new information technology and how to leverage it for corporate survival and to gain competitive advantage in volatile business environment. Although there is no shortage of positive reports on the success of ERP installations, many companies have invested millions of dollars in this direction with little to show for its success. Since many of the ERP failures today can be attributed to inadequate planning and poor execution in the implementation and closure of projects. The aim of this article is to offer some solutions to avert potential pitfalls in ERP implementation.

A Study of Los Angeles Public School Design in Identifying Community Improvement

  • Reeder, Eric D.;Park, Suh-Jun;Kim, Youngsuk
    • Architectural research
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    • 제18권4호
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    • pp.171-178
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    • 2016
  • Architectural utility in Richard Neutra's early twentieth century modern school design was paramount in progressively shaping salience of academic institutions, in part to move beyond neoclassical traditions in style based design. The intention being to address school and community through modern architectural solutions. Expanding on Neutra's practice, the planning and design of new public schools in Los Angeles, are advocating the integration of institutional and public spaces. This research will document through qualitative analysis of institutional design within transitioning neighborhoods, a utilitarian approach that has become foundational for positive urban change. The focus of this research will reflect upon contemporary schools designed by DalyGenik Architecture, Coop Himmelblau and Michael Maltzen Architecture. Comparing with Neutra's early modernist approach, the selected case studies will address material and spatial applications having redefined functional relationships of interior space, architectural envelope and an interconnected public realm. A dynamic peripheral condition in new school design has emerged with the elimination of decorative adornment, clarifying utilitarian intentions of institutional service to and the rejuvenation of public realms and community spaces.

E-logistics에 있어서 화주의 평가체계에 관한 실증적 연구 : 국제 해운분야를 중심으로 (Empirical Analysis of Shipper Requirement for E-logistics : The Case of International Shipping)

  • Cho, Chan-Hyouk;Strohmaier, James G.
    • 한국항만경제학회지
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    • 제20권2호
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    • pp.217-234
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    • 2004
  • Information technology has been transforming the relationship between shippers and carriers, but an unresolved question remains: what is the relative importance to shippers of service versus cost benefits of e-logistics solutions? This research develops and empirically tests a model to determine how Internet-based logistical operations in international shipping impact on the relative importance of cost versus service benefits to shippers. Contrary to expectations, results show that shippers perceived cost benefits from well-designed web sites, undoubtedly a consequence of perceptions that multi-function portals with ease of access contributed to savings in time and money. Another result was the confirmation of the positive effects of cargo tracing and bill of lading issuance on service-related factors. Finally, this study draws attention to the need for improvements in on-line booking capabilities and development of a comprehensive common portal; issues that must be addressed for shipping lines to succeed in an increasingly competitive e-logistics market.

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무전해 Ni 복합도금에서 분말의 공석에 미치는 Na 이온의 영향 (A Study of the Effects of Na Ion on Codeposition of Particles in the Formation of Electroless Ni Composite Coatings)

  • 이원해;이승평
    • 한국표면공학회지
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    • 제22권2호
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    • pp.101-108
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    • 1989
  • Effects of Na+ ion on zeta potential of SiC and Al2O3 particles suspended in nikel sufate and nickel chloride solutions were investigated. various complexing agents for Ni2+ ion were added to electroless Ni composite bath and the effects of the complexing agents on zeta potential and codeposition of the particles from the baths were studied. It was confirmed that Na+ ion was absorbed on the particles bringing about the positive surface charge and thus they promoted the entrapment of the particles into the nickel deposit. On the basis of these results it was possible to deposit SiCc particle in nickel chloride electrolyte containing complex agent such as trisodium citrate+sodium succinate.

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Effects of Protein Unfolding and Soluble Aggregates Formation on the Gel Strength of Whey Proteins

  • Park, Moon-Jung;Michael E. Mangino
    • Preventive Nutrition and Food Science
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    • 제2권4호
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    • pp.281-284
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    • 1997
  • Heat-induced gelation is an important functional property of whey proteins. Preheating of calcium reduced whey was reported to increase gel strength. 5% whey-protein solutions were preheated at pH7 and at various temperatures(60~8$0^{\circ}C$) for 15 minutes. The amount of soluble aggregates and denaturation enthalpy of preheated whey proteins were measured. Preheating temperature was negatively correlated with denaturation enthalpy($R^2$=0.857, P=0.08) and positive with the amount of soluble aggregates($R^2$=0.921, P=0.002). Denaturation enthalpy was negatively correlated with gel strength($R^2$=0.93, P=0.002). Soluble aggregates and gel strength were positively correlated($R^2$=0.972, P=0.0003). The formation of three dimensional gel network requires controlled protein denaturation and aggregation. Since preheating leads to the partial denaturation of proteins and the formation of soluble aggregates, preheated whey proteins have a higher gel strength than non-preheated one.

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A UNIFORMLY CONVERGENT NUMERICAL METHOD FOR A WEAKLY COUPLED SYSTEM OF SINGULARLY PERTURBED CONVECTION-DIFFUSION PROBLEMS WITH BOUNDARY AND WEAK INTERIOR LAYERS

  • CHAWLA, SHEETAL;RAO, S. CHANDRA SEKHARA
    • Journal of applied mathematics & informatics
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    • 제33권5_6호
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    • pp.635-648
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    • 2015
  • We consider a weakly coupled system of singularly perturbed convection-diffusion equations with discontinuous source term. The diffusion term of each equation is associated with a small positive parameter of different magnitude. Presence of discontinuity and different parameters creates boundary and weak interior layers that overlap and interact. A numerical method is constructed for this problem which involves an appropriate piecewise uniform Shishkin mesh. The numerical approximations are proved to converge to the continuous solutions uniformly with respect to the singular perturbation parameters. Numerical results are presented which illustrates the theoretical results.

Calibration of Inertial Measurement Units Using Pendulum Motion

  • Choi, Kee-Young;Jang, Se-Ah;Kim, Yong-Ho
    • International Journal of Aeronautical and Space Sciences
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    • 제11권3호
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    • pp.234-239
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    • 2010
  • The utilization of micro-electro-mechanical system (MEMS) gyros and accelerometers in low-level inertial measurement unit (IMU) influences cost effectiveness in a positive way under the condition that device error characteristics are fully calibrated. The conventional calibration process utilizes a rate table; however, this paper proposes a new method for achieving reference calibration data from the natural motion of pendulum to which the IMU undergoing calibration is attached. This concept was validated with experimental data. The pendulum angle measurements correlate extremely well with the solutions acquired from the pendulum equation of motion. The calibration data were computed using the regression method. The whole process was validated by comparing the measurement from the 6 sensor components with the measurements reconstructed using the identified calibration data.

EXISTENCE AND CONCENTRATION RESULTS FOR KIRCHHOFF-TYPE SCHRÖ DINGER SYSTEMS WITH STEEP POTENTIAL WELL

  • Lu, Dengfeng
    • 대한수학회보
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    • 제52권2호
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    • pp.661-677
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    • 2015
  • In this paper, we consider the following Kirchhoff-type Schr$\ddot{o}$dinger system $$\{-\(a_1+b_1{\int}_{\mathbb{R^3}}{\mid}{\nabla}u{\mid}^2dx\){\Delta}u+{\gamma}V(x)u=\frac{2{\alpha}}{{\alpha}+{\beta}}{\mid}u{\mid}^{\alpha-2}u{\mid}v{\mid}^{\beta}\;in\;\mathbb{R}^3,\\-\(a_2+b_2{\int}_{\mathbb{R^3}}{\mid}{\nabla}v{\mid}^2dx\){\Delta}v+{\gamma}W(x)v=\frac{2{\beta}}{{\alpha}+{\beta}}{\mid}u{\mid}^{\alpha}{\mid}v{\mid}^{\beta-2}v\;in\;\mathbb{R}^3,\\u,v{\in}H^1(\mathbb{R}^3),$$ where $a_i$ and $b_i$ are positive constants for i = 1, 2, ${\gamma}$ > 0 is a parameter, V (x) and W(x) are nonnegative continuous potential functions. By applying the Nehari manifold method and the concentration-compactness principle, we obtain the existence and concentration of ground state solutions when the parameter ${\gamma}$ is sufficiently large.

DYNAMIC BEHAVIOR OF A PREDATOR-PREY MODEL WITH STAGE STRUCTURE AND DISTRIBUTED DELAY

  • Zhou, Xueyong
    • Journal of applied mathematics & informatics
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    • 제28권1_2호
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    • pp.193-207
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    • 2010
  • In this paper, a predator-prey model with stage structure and distributed delay is investigated. Mathematical analyses of the model equation with regard to boundedness of solutions, nature of equilibria, permanence, extinction and stability are performed. By the comparison theorem, a set of easily verifiable sufficient conditions are obtained for the global asymptotic stability of nonnegative equilibria of the model. Taking the product of the per-capita rate of predation and the rate of conversing prey into predator as the bifurcating parameter, we prove that there exists a threshold value beyond which the positive equilibrium bifurcates towards a periodic solution.