• Title/Summary/Keyword: stationary solution

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Chromatographic Behavior of Proteins on Stationary Phase with Aminocarboxy Ligand

  • Li, Rong;Ju, Ming-Yang;Chen, Bin;Sun, Qing-Yuan;Chen, Guo-Liang;Shi, Mei;Wang, Xiao-Gang;Zheng, Jian-Bin
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.590-594
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    • 2011
  • An aminocarboxy aspartic acid-bonded silica (Asp-Silica) stationary phase was synthesized using L-aspartic acid as ligand and silica gel as matrix. The standard protein mixtures were separated with prepared chromatographic column. The effects of solution pH, salt concentration and metal ion on the retention of proteins were examined, and also compared with traditional iminodiacetic acid-bonded silica (IDA-Silica) column. The results show that Asp-Silica column exhibited an excellent separation performance for proteins. The retention of proteins on Asp-Silica stationary phase was consistent with electrostatic characteristic of cation-exchange. The stationary phase displayed typical metal chelate property after fixing copper ion (II) on Asp-Silica. Under competitive eluting condition, protein mixtures were effectively isolated. Asp ligand showed better ion-exchange and metal chelating properties as compared with IDA ligand.

ALGORITHMIC SOLUTION FOR M/M/c RETRIAL QUEUE WITH $PH_2$-RETRIAL TIMES

  • Shin, Yang-Woo
    • Journal of applied mathematics & informatics
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    • v.29 no.3_4
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    • pp.803-811
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    • 2011
  • We present an algorithmic solution for the stationary distribution of the M/M/c retrial queue in which the retrial times of each customer in orbit are of phase type distribution of order 2. The system is modeled by the level dependent quasi-birth-and-death (LDQBD) process.

MATHEMATICAL ANALYSIS OF NONLINEAR DIFFERENTIAL EQUATION ARISING IN MEMS

  • Zhang, Ruifeng;Li, Na
    • Bulletin of the Korean Mathematical Society
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    • v.49 no.4
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    • pp.705-714
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    • 2012
  • In this paper, we study nonlinear equation arising in MEMS modeling electrostatic actuation. We will prove the local and global existence of solutions of the generalized parabolic MEMS equation. We present that there exists a constant ${\lambda}^*$ such that the associated stationary problem has a solution for any ${\lambda}$ < ${\lambda}^*$ and no solution for any ${\lambda}$ > ${\lambda}^*$. We show that when ${\lambda}$ < ${\lambda}^*$ the global solution converges to its unique maximal steady-state as $t{\rightarrow}{\infty}$. We also obtain the condition for the existence of a touchdown time $T{\leq}{\infty}$ for the dynamical solution. Furthermore, there exists $p_0$ > 1, as a function of $p$, the pull-in voltage ${\lambda}^*(p)$ is strictly decreasing with respect to 1 < $p$ < $p_0$, and increasing with respect to $p$ > $p_0$.

Performance Improvement of a Floating Solution Using a Recursive Filter

  • Cho, Sung Lyong;Lee, Sang Jeong;Park, Chansik
    • Journal of Positioning, Navigation, and Timing
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    • v.3 no.3
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    • pp.117-122
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    • 2014
  • In CDGPS, ambiguity resolution is determined by the performance of a floating solution, and thus, the performance needs to be improved. In the case of precise positioning at a stationary position, the batch method using multiple measurements is used for the accuracy improvement of a position. The position accuracy performance of a floating solution is outstanding, but it has a problem of high computation cost because all measurements are used. In this study, to improve the floating solution performance of the initial static user in CDGPS, a floating solution method using a recursive filter was implemented. A recursive filter estimates the position solution of the current epoch using the position solution of up to the previous epoch and the pseudorange measurement of the current epoch. The computation cost of the floating solution method using a recursive filter was found to be similar to that of the epoch-by-epoch method. Also, based on actual GPS signals, the floating solution performance was found to be similar to that of the batch method. The floating solution using a recursive filter could significantly improve the performance of the prompt initial position and ambiguity resolution of the initial static user.

Efficient MCS for random vibration of hysteretic systems by an explicit iteration approach

  • Su, Cheng;Huang, Huan;Ma, Haitao;Xu, Rui
    • Earthquakes and Structures
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    • v.7 no.2
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    • pp.119-139
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    • 2014
  • A new method is proposed for random vibration anaylsis of hysteretic systems subjected to non-stationary random excitations. With the Bouc-Wen model, motion equations of hysteretic systems are first transformed into quasi-linear equations by applying the concept of equivalent excitations and decoupling of the real and hysteretic displacements, and the derived equation system can be solved by either the precise time integration or the Newmark-${\beta}$ integration method. Combining the numerical solution of the auxiliary differential equation for hysteretic displacements, an explicit iteration algorithm is then developed for the dynamic response analysis of hysteretic systems. Because the computational cost for a large number of deterministic analyses of hysteretic systems can be significantly reduced, Monte-Carlo simulation using the explicit iteration algorithm is now viable, and statistical characteristics of the non-stationary random responses of a hysteretic system can be obtained. Numerical examples are presented to show the accuracy and efficiency of the present approach.

Fatigue Damage Combination for Spread Mooring System under Stationary Random Process with Bimodal Spectrum Characteristics (바이모달 스펙트럼 특성을 가지는 정상확률과정에 대한 다점계류라인의 피로손상도 조합기법 연구)

  • Lim, Yu-Chang;Kim, Kyung-Su;Choung, Joon-Mo
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.6
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    • pp.813-820
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    • 2010
  • The spread mooring system for FPSO is developed to explore deep sea area, in which swell is dominant. It is known that the tension response of mooring lines in this sea area shows bimodal spectrum. Assuming normal distribution of tension profile and Rayleigh distribution of tension amplitude, the power spectral density function (PSD) of the mooring tension under the bimodal stationary random process is applied for the calculation of spectrum fatigue. Three popular methods, which are simple summation method, combined spectrum method and Jioa-Moan method, are used to combine fatigue damages from bimodal spectrum characteristics. Each damage value is compared with damage using Rainflow Cycle Counting (RCC) method which is believed to be close to exact solution. Vanmarcke' parameter and RMS(Root Mean Square) ratio are employed to assess relative damage variations between from RCC method and from three combination methods. Finally the most reliable fatigue damage combining method for spread mooring system is suggested.

Inertia Force Problem and Nozzle Contact Mechanism of Linear Motor Drive Injection Molding Machine

  • Bang, Young-Bong;Susumu Ito
    • International Journal of Precision Engineering and Manufacturing
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    • v.4 no.5
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    • pp.34-40
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    • 2003
  • This paper presents the inertial force problem of ultrahigh-speed injection molding machine using linear motors, and presents its solutions. To make very thin products by injection molding, very high injection speed is required, and linear motors are used for this purpose. However, direct drive by linear motors may cause brief nozzle separation from the sprue bushing because of the inertia force which is as large as the total output thrust of the linear motors, and this momentary separation can cause molten plastic to leak. In this paper, two solutions are proposed for this inertia force problem. One is the mechanical cancellation of the inertia force, and the other is to increase the nozzle contact force. With the latter solution, the stationary platen bending worsens, so a new nozzle contact mechanism is also proposed, which can prevent the stationary platen bending.

Formulating Analytical Solution of Network ODE Systems Based on Input Excitations

  • Bagchi, Susmit
    • Journal of Information Processing Systems
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    • v.14 no.2
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    • pp.455-468
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    • 2018
  • The concepts of graph theory are applied to model and analyze dynamics of computer networks, biochemical networks and, semantics of social networks. The analysis of dynamics of complex networks is important in order to determine the stability and performance of networked systems. The analysis of non-stationary and nonlinear complex networks requires the applications of ordinary differential equations (ODE). However, the process of resolving input excitation to the dynamic non-stationary networks is difficult without involving external functions. This paper proposes an analytical formulation for generating solutions of nonlinear network ODE systems with functional decomposition. Furthermore, the input excitations are analytically resolved in linearized dynamic networks. The stability condition of dynamic networks is determined. The proposed analytical framework is generalized in nature and does not require any domain or range constraints.

On the Approximate Solution of Nonclassically Damped Linear Systems under Random Excitations (비고전적 감쇠를 갖는 랜덤 진동계의 근사적 해석기법에 대한 연구)

  • 황재혁;유병성;박지상
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1998.04a
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    • pp.108-113
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    • 1998
  • Nonclassically damping comes from drastic variations of energy absorption rates of the materials in different parts of structures, or from the external damping sources inserted into the structures. In this study, an approximate method based on the real valued normal modes to analyze the responses of a nonclassically damped system under stationary random excitations has been suggested. The dynamic responses of an aircraft landing gear under stationary random excitations has been analyzed using the proposed method. It has been found by a series of simulation that this method is superior to other approaches in respect of computational effort and accuracy.

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