• 제목/요약/키워드: computational mathematics

검색결과 3,201건 처리시간 0.022초

Boundary layer analysis of persistent moving horizontal needle in Blasius and Sakiadis magnetohydrodynamic radiative nanofluid flows

  • Krishna, Penem Mohan;Sharma, Ram Prakash;Sandeep, Naramgari
    • Nuclear Engineering and Technology
    • /
    • 제49권8호
    • /
    • pp.1654-1659
    • /
    • 2017
  • The boundary layer of a two-dimensional forced convective flow along a persistent moving horizontal needle in an electrically conducting magnetohydrodynamic dissipative nanofluid was numerically investigated. The energy equation was constructed with Joule heating, viscous dissipation, uneven heat source/sink, and thermal radiation effects. We analyzed the boundary layer behavior of a continuously moving needle in Blasius (moving fluid) and Sakiadis (quiescent fluid) flows. We considered Cu nanoparticles embedded in methanol. The reduced system of governing Partial differential equations (PDEs) was solved by employing the Runge-Kutta-based shooting process. Computational outcomes of the rate of heat transfer and friction factors were tabulated and discussed. Velocity and temperature descriptions were examined with the assistance of graphical illustrations. Increasing the needle size did not have a significant influence on the Blasius flow. The heat transfer rate in the Sakiadis flow was high compared with that in the Blasius flow.

Group Decision Making Using Intuitionistic Hesitant Fuzzy Sets

  • Beg, Ismat;Rashid, Tabasam
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • 제14권3호
    • /
    • pp.181-187
    • /
    • 2014
  • Dealing with uncertainty is always a challenging problem. Intuitionistic fuzzy sets was presented to manage situations in which experts have some membership and non-membership value to assess an alternative. Hesitant fuzzy sets was used to handle such situations in which experts hesitate between several possible membership values to assess an alternative. In this paper, the concept of intuitionistic hesitant fuzzy set is introduced to provide computational basis to manage the situations in which experts assess an alternative in possible membership values and non-membership values. Distance measure is defined between any two intuitionistic hesitant fuzzy elements. Fuzzy technique for order preference by similarity to ideal solution is developed for intuitionistic hesitant fuzzy set to solve multi-criteria decision making problem in group decision environment. An example is given to illustrate this technique.

HEISENBERG GROUPS - A UNIFYING STRUCTURE OF SIGNAL THEORY, HOLOGRAPHY AND QUANTUM INFORMATION THEORY

  • Binz, Ernst;Pods, Sonja;Schempp, Walter
    • Journal of applied mathematics & informatics
    • /
    • 제11권1_2호
    • /
    • pp.1-57
    • /
    • 2003
  • Vector fields in three-space admit bundles of internal variables such as a Heisenberg algebra bundle. Information transmission along field lines of vector fields is described by a wave linked to the Schrodinger representation in the realm of time-frequency analysis. The preservation of local information causes geometric optics and a quantization scheme. A natural circle bundle models quantum information visualized by holographic methods. Features of this setting are applied to magnetic resonance imaging.

A GOAL PROGRAMMING MODEL FOR THE BEST POSSIBLE SOLUTION TO LOAN ALLOCATION PROBLEMS

  • Sharma, Dinesh-K.;Ghosh, Debasis;Alade, Julius-A.
    • Journal of applied mathematics & informatics
    • /
    • 제9권1호
    • /
    • pp.197-211
    • /
    • 2002
  • In this paper, we propose a multi-Criteria decision making approach to address the problem of finding the best possible solution in credit unions. Sensitivity analysis on the priority structure of the goals has been performed to obtain all possible solutions. The study uses the Euclidean distance method to measure distances of all possible solutions from the identified ideal solution. The possible optimum solution is determined from the minimum distance between the ideal solution and other possible solutions of the Problem.

ON EXTREMAL SORT SEQUENCES

  • Yun, Min-Young;Keum, Young-Wook
    • Journal of applied mathematics & informatics
    • /
    • 제9권1호
    • /
    • pp.239-252
    • /
    • 2002
  • A sort sequence $S_n$ is sequence of all unordered pairs of indices in $I_n$={1,2,…n}. With a sort sequence $S_n$ = ($s_1,S_2,...,S_{\frac{n}{2}}$),one can associate a predictive sorting algorithm A($S_n$). An execution of the a1gorithm performs pairwise comparisons of elements in the input set X in the order defined by the sort sequence $S_n$ except that the comparisons whose outcomes can be inferred from the results of the preceding comparisons are not performed. A sort sequence is said to be extremal if it maximizes a given objective function. First we consider the extremal sort sequences with respect to the objective function $\omega$($S_n$) - the expected number of tractive predictions in $S_n$. We study $\omega$-extremal sort sequences in terms of their prediction vectors. Then we consider the objective function $\Omega$($S_n$) - the minimum number of active predictions in $S_n$ over all input orderings.

BAYESIAN MODEL SELECTION IN REGRESSION MODEL WITH AUTOREGRESSIVE ERRORS

  • Chung, Youn-Shik;Sohn, Keon-Tae;Kim, Sung-Duk;Kim, Chan-Soo
    • Journal of applied mathematics & informatics
    • /
    • 제9권1호
    • /
    • pp.289-301
    • /
    • 2002
  • This paper considers the Bayesian analysis of the regression model wish autoregressive errors. The Bayesian approach for finding the order p of autoregressive error is proposed and the proposed method can be simplified by generalized Savage-Dicky density ratio(Verdinelli and Wasser-man, [18]). And the Markov chain Monte Carlo method(Gibbs sample, [7]) is used in order to overcome the difficulty of Bayesian computations. Final1y, several examples are used to illustrate our proposed methodology.

AN ANALYSIS FOR THE BIDIRECTIONAL QUEUEING NETWORK

  • Lim, Jong-Seul
    • Journal of applied mathematics & informatics
    • /
    • 제9권1호
    • /
    • pp.349-357
    • /
    • 2002
  • In this paper, we analyze queueing behaviors and investigate the possibilities of reducing and controlling shortages and oversupplies in the bidirectional queueing system which forms a negative queue by demand and a positive queue by supply. Interarrival times of units in the bidirectional queueing system investigated are exponetially distributed. Instant pairing off implies that queue can be either positive or negative, but not both at the same time. The results include a proof that sum of queue lengths is minimized if rates of demand and supply in each system are equal and optimum solutions for rates of supply which minimize the sum of queue lengths when rates of demand and sum of rates of supply are given. In addition, the relationship between the ordinary queueing system and the bidirectional queueing system is investigated.

NON-FRAGILE GUARANTEED COST CONTROL OF UNCERTAIN LARGE-SCALE SYSTEMS WITH TIME-VARYING DELAYS

  • Park, Ju-H.
    • Journal of applied mathematics & informatics
    • /
    • 제9권1호
    • /
    • pp.61-76
    • /
    • 2002
  • The robust non-fragile guaranteed cost control problem is studied in this paper for class of uncertain linear large-scale systems with time-varying delays in subsystem interconnections and given quadratic cost functions. The uncertainty in the system is assumed to be norm-hounded arid time-varying. Also, the state-feedback gains for subsystems of the large-scale system are assumed to have norm-bounded controller gain variations. The problem is to design state feedback control laws such that the closed-loop system is asymptotically stable and the closed-loop cost function value is not more than a specified upper bound far all admissible uncertainties. Sufficient conditions for the existence of such controllers are derived based on the linear matrix inequality (LMI) approach combined with the Lyapunov method. A parameterized characterization of the robust non-fragile guaranteed cost contrellers is 7iven in terms of the feasible solution to a certain LMI. Finally, in order to show the application of the proposed method, a numerical example is included.

A MULTILEVEL BLOCK INCOMPLETE CHOLESKY PRECONDITIONER FOR SOLVING NORMAL EQUATIONS IN LINEAR LEAST SQUARES PROBLEMS

  • Jun, Zhang;Tong, Xiao
    • Journal of applied mathematics & informatics
    • /
    • 제11권1_2호
    • /
    • pp.59-80
    • /
    • 2003
  • An incomplete factorization method for preconditioning symmetric positive definite matrices is introduced to solve normal equations. The normal equations are form to solve linear least squares problems. The procedure is based on a block incomplete Cholesky factorization and a multilevel recursive strategy with an approximate Schur complement matrix formed implicitly. A diagonal perturbation strategy is implemented to enhance factorization robustness. The factors obtained are used as a preconditioner for the conjugate gradient method. Numerical experiments are used to show the robustness and efficiency of this preconditioning technique, and to compare it with two other preconditioners.

METRIZATION OF THE FUNCTION SPACE M

  • Lee, Joung-Nam;Yang, Young-Kyun
    • Journal of applied mathematics & informatics
    • /
    • 제11권1_2호
    • /
    • pp.391-399
    • /
    • 2003
  • Let (X,S,$\mu$) be a measure space and M be the vector space of all real valued S-measurable functions defined on (X,S,$\mu$). For $E\;{\in}\;S$ with $\mu(E)\;<\;{\infty}$, $d_E$ is a pseudometric on M. With the notion of D = {$d_E$\mid$E\;{\in}\;S,\mu(E)\;<\;{\infty}$}, in this paper we investigate some topological structure T of M. Indeed, we shall show that it is possible to define a complete invariant metric on M which is compatible with the topology T on M.