Showing papers in "International Journal of Mathematical Modelling & Computations in 2013"

Energy Aware Distributed Partitioning Detection and Connectivity Restoration Algorithm in Wireless Sensor Networks

Abstract: Mobile sensor networks rely heavily on inter-sensor connectivity for collection of data. Nodes in these networks monitor dierent regions of an area of interest and collectively present a global overview of some monitored activities or phenomena. A failure of a sensor leads to loss of connectivity and may cause partitioning of the network into disjoint segments. A number of approaches have been recently proposed that pursue node relocation in order to restore connectivity. DCR is a distributed partitioning detection and connectivity restora- tion algorithm to tolerate the failure of sensors. DCR proactively identies sensors that are critical to the network connectivity based on local topological information, and designates appropriate, preferably non-critical, backup nodes. Upon failure detection, the backup sensor initiates a recovery process that may involve coordinated relocation of multiple sensors. Here we proposed Energy aware Distributed partitioning detection and connectivity restoration al- gorithm (EDCR) that is an improvement of DCR algorithm. Therefore reducing the message exchange overhead, lower energy consumption, and thus will increase the network lifetime.

Solving integro-differential equation by using b- spline interpolation

Abstract: In this paper a numerical technique based on the B-spline method is presented for the solution of Fredholm integro-differential equations. To illustrate the efficiency of the method some examples are introduced and the results are compared with the exact solution.

Approximation of 3D-Parametric Functions by Bicubic B-spline Functions

Abstract: In this paper we propose a method to approximate a parametric 3 D -function by bicubic B-spline functions

Spline Collocation Method for Solving Boundary Value Problems

Abstract: The spline collocation method is used to approximate solutions of boundary value problems. The convergence analysis is given and the method is shown to have second-order convergence. A numerical illustration is given to show the pertinent features of the technique.

B-spline Collocation Approach for Solution of Klein-Gordon Equation

Abstract: We develope a numerical method based on B-spline collocation method to solve linear Klein-Gordon equation. The proposed scheme is unconditionally stable. The results of numerical experiments have been compared with the exact solution to show the eciency of the method computationally. Easy and economical implementation is the strength of this approach.

Game of coordination for bacterial pattern formation: a finite automata modelling

Abstract: In this paper, we use game theory to describe the emergence of self-organization and consequent pattern formation through communicative cooperation in Bacillus subtilis colonies. The emergence of cooperative regime is modelled as an n-player Assurance game, with the bacterial colonies as individual players. The game is played iteratively through cooperative communication, and mediated by exchange of information about the local environment between the different bacterial colonies comprising the system. The iteration causes the interactive system to grow and produce beautiful complex spatial patterns signaling the emergence of self-organization. In laboratory, we have the bacterial growth environment mimicked in Petri dish, where chemical stress is introduced in a three- fold manner: through modification of nutrition and substrate amounts and introducing an antibiotic in the system. In our model, bacteria colonies, treated asindividual players, interact within the environment and grow according to a set of rules. The rules capture the biotic processes that allow bacteria to grow in the hostile environment, and cope with the stress. We find the effects of sophisticated communications and information-sharing between bacterial colonies to be a vital determinant for bacterial growth, which is manifested in the Petri dish as complex spatial patterns, often at fractal scales. As a formal description of the above game, we model the emergence of this cooperative behaviour as finite deterministic automata, whose transition function is informed by the Assurance game pay-off. Consequently, the exercise allows us to derive a grammar that provides the rules for describing the bacterial interactions leading to the emergence of the spatial structures.

Fuzzy k -nearest neighbor method to classify data in a closed area

Abstract: Clustering of objects is an important area of research and application in variety of fields. In this paper we present a good technique for data clustering and application of this Technique for data clustering in a closed area. We compare this method with K-nearest neighbor and K-means.

Unsteady convective diffusion in a herschel–bulkley fluid in a conduit with interphase mass transfer

Abstract: The combined effect of non-Newtonian rheology and irreversible boundary reaction on dispersion in a Herschel-Bulkley fluid through a conduit (pipe/channel) is studied by using generalized dispersion model. The study explains the development of dispersive transport following the injection of a tracer in terms of three effective transport coefficients namely exchange, convective and dispersion coefficients. It is found that the exchange coefficient does not depend on yield stress and power law index but the convective and dispersion coefficients depend on yield stress and power law index.

Discrete-time gi/d-msp/1/k queue with n threshold policy

Abstract: This paper presents a discrete-time single-server finite buffer N threshold policy queue with renewal input and discrete Markovian service process. The server terminates service whenever the system becomes empty, and recommences service as soon as the number of waiting customers in the queue is N. We obtain the system-length distributions at pre-arrival and arbitrary epochs using the supplementary variable and the imbedded Markov chain techniques. Various performance measures such as the loss probability, mean queue length and mean waiting time in the queue along with some numerical results have been presented. The proposed model has potential applications in the areas of computer and telecommunication systems.

A new approach to solve differential equations arising in fluid mechanics

Abstract: The purpose of this study is to demonstrate the potential of Imperialist Com- petitive Algorithm (ICA) for solving Blasius dierential equation. This algorithm is inspired by competition mechanism among Imperialists and colonies and has demonstrated excel- lent capabilities such as simplicity, accuracy, faster convergence and better global optimum achievement in contrast to other evolutionary algorithms. To validate the proposed approach, the results of ICA were nally compared with exact solution of variational iteration method (VIM). Based on the results, current method can be easily extended to solve a wide range of problems.

Mathematical Analysis of Newly Designed Two Porous Layers Slider Bearing with a Convex Pad Upper Surface Considering Slip and Squeeze Velocity Using Ferrofluid Lubricant

Abstract: This paper proposes mathematical modeling and analysis of ferrofluid lubricated newly designed slider bearing having convex pad (surface or plate) stator with two porous layers attached to the slider. The problem considers the effect of slip velocity proposed by Sparrow et. al .[1] and modified by Shah et. al. [2] at the film-porous interface. The squeeze velocity V= − which appears when the upper impermeable plate approach to the lower one, is also considered here for study. The magnetic field is assumed to be oblique to the lower plate. From the Reynolds’s equation of the above model, expressions for dimensionless form of pressure and load carrying capacity are obtained. The expression for the dimensionless load carrying capacity is then solved numerically to examine its possible effect on the designed bearing system

Solving Linear Sixth-Order Boundary Value Problems by Using Hyperbolic Uniform Spline Method

Abstract: In this paper, a numerical method is developed for solving a linear sixth order boundaryvalue problem (6VBP ) by using the hyperbolic uniform spline of order 3 (lower order). Thereis proved to be first-order convergent. Numerical results confirm the order of convergencepredicted by the analysis.

On (a,c,b) Policy Queue with Change Over Times Under Bernoulli Schedule Vacation Interruption

Abstract: This paper analyzes a renewal input working vacations queue with change over times and Bernoulli schedule vacation interruption under (a,c,b) policy. The service and vacation times are exponentially distributed. The server begins service if there are at least c units in the queue and the service takes place in batches with a minimum of size a and a maximum of size b (a<=c <= b). The change over periods follow if there are (c-1) customers (at vacation completion instant) or (a-1) customers at service completion instants. The steady state queue length distributions at arbitrary and pre-arrival epochs are obtained. Performance measures and optimal cost policy are presented with numerical experiences. The genetic algorithm and quadratic fit search method are employed to search the optimal values of some important parameters of the system.

On coneigenvalues of a complex square matrix

Abstract: In this paper, we show that a matrix A in Mn(C) that has n coneigenvectors, where coneigenvalues associated with them are distinct, is condiagonalizable. And also show that if all coneigenvalues of conjugate-normal matrix A be real, then it is symmetric.

Application of Fuzzy Expansion Methods for Solving Fuzzy Fredholm- Volterra Integral Equations of the First Kind

Abstract: In this paper we intend to offer new numerical methods to solve the fuzzy Fredholm- Volterra integral equations of the first kind $(FVFIE-1)$. Some examples are investigated to verify convergence results and to illustrate the efficiently of the methods.

Improving the selection symmetric weights as a secondary goal in dea cross-efficiency evaluation

Abstract: Recently, some authors proposed the use of symmetric weights for computing the elements of cross-efficiency matrix. In spite of the fact that the proposed method decreases the number of zero weights, a large number of zero weights may still exist among input and output symmetric weights. To decrease the number of input and output symmetric weights, this paper improves the proposed secondary goal model. The improved method generates more acceptable results in the ranking process of the decision making units (DMUs). Finally, a numerical example is provided to illustrate the applicability of the proposed method.

An Electromagnetism-like algorithm for fixed charge solid transportation problem

Abstract: Fixed charge solid transportation problem (FCSTP) is one of the main and most important problems in transportation and network research areas. To tackle such an NP-hard problem, An Electromagnetism-like algorithm (EM) is employed. To the best of our knowledge, EM has been considered for any kind of transportation problems. Due to the significant role of parameters on the algorithm’s performance, a calibration in EM is carried out with the aid of a set of experimental design. The efficiency of employed parameters is measured by the experimental design method. To evaluate the performance of the proposed EM, a computational study has been conducted and the associated results obtained by the EM are compared with simulated annealing algorithm (SA).

Using Free Disposal Hull Models in Supply Chain Management

Abstract: To help improve customer relationship management (CRM), greater emphasis is given to the aspect of quality in the supply chain management and improve supply chain performance through is integrated business management and strategic partnerships. On the other hand, strategic supply chain management decisions are made at a company level that determine benets and eciencies of the supply chain and eective management of supply chains assists to product and delivery of a variety of products at low cost, high quality products, short lead times and services at the least cost. Hence, performance evaluation is of most importance for eective supply chain management. This paper gives a new application of DEA model, and FDH model to evaluate the supply chain. The basic motivation is to ensure that eciency evaluations are eected from only observed performances.

A new modified Homotopy Perturbation method for solving linear second-order Fredholm Integro-differential Equations

Abstract: In this paper, we tried to accelerate the rate of convergence in solving second-order Fredholm type Integro-differential equations using a new method which is based on Improved homotopy perturbation method (IHPM) and applying accelerating parameters. This method is very simple and the result is obtained very fast.

Identification and prioritization of environmental factors affecting the implementation of organizational strategies in the insurance industry (a case study of asia insurance)

Abstract: A company or organization requires special unique strategies to achieve orga- nizational goals which not only do bring about macro-and long-term goals, but also create competitive status for the organization. However, developing dierent strategies will not guar- antee the organization's success, but the implementation of strategy is the most important step in the entire life of strategic management of the organization. The main objective of this study is to provide a classication of environmental barriers in eective implementation of strategies in Asia insurance company. In this research, experts of insurance industry were considered as statistical society, in which the number of managers, senior professionals and experts with more than 3 years of experience in Asia Central Insurance and its branches across Tehran was about 340 which comprised the statistical society of this research. Morgan table was applied for sampling and a number of 181 people were selected as samples to dis- tribute the questionnaires. This study is descriptive-analytical and practical. Data from the questionnaire (the questionnaire study and design of a new questionnaire was prepared with the help of experts) and data analysis software for regression analysis was performed using SPSS 18; in which organization, competitive factors were identied as the most inuential environmental factors in implementation of organizational strategies.

Application of hpm and ham to the first form of blasius equation

Abstract: In this work, the Blasius equation is studied. Homotopy perturbation method (HPM) and homotopy analysis method (HAM) are applied to obtain its solution. Comparison with variational iteration method (VIM) is made to highlight the significant features of employed methods and their capability of handling nonlinear problems. The outcome shows the success of (HPM) and (HAM) for solving nonlinear problems arising in fluid mechanics.

Application Neural Network to Solve Ordinary Differential Equations

Abstract: In this paper, we introduce a hybrid approach based on neural network and optimization teqnique to solve ordinary differential equation. In proposed model we use heyperbolic secont transformation function in hiden layer of neural network part and bfgs teqnique in optimization part. In comparison with existing similar neural networks proposed model provides solutions with high accuracy. Numerical examples with simulation results illustrate the effectiveness of the proposed model.

On Quasilinear Elliptic Systems Involving Multiple Critical Exponents

Abstract: In this paper, we consider the existence of a non-trivial weak solution to a quasilinear elliptic system involving critical Hardy exponents. The main issue of the paper is to understand the behavior of these Palais-Smale sequences. Indeed, the principal difficulty here is that there is an asymptotic competition between the energy functional carried by the critical nonlinearities. Then by the variational method, we obtain the existence non-trivial week solution for the system.

Cost and Allocative efficiency in Buyer-Supplier

Abstract: The aim of this paper is the evaluation overall performance of buyer-supplier relationships. In some situations the cost of inputs in a buyer-supplier chain are available, on the other hand, achieving a low cost position is necessary for most businesses. And, in a buyer-supplier chain wants to know how assign inputs with the least cost. This paper introduces cost efficiency with same and dierent costs of inputs. Moreover, cost efficiency not only does it improve protability, but businesses with a low cost position are better able to drive growth through higher investment in sales, marketing, improve customer service and new product development, as well as more competitive pricing in buyer-supplier. Moreover, in this paper we introduce allocative and technical eciency of buyer-supplier that based on the Data envel-opment analysis (DEA). And show how far the buyer-supplier is from the point of maximum protability given the existing market prices for inputs and products, and also is achieved when the value consumers place on a good or service equals the cost of the resources used up in production. Finally, we illustrate the proposed models by an example.

The elzaki homotopy perturbation method for partial differential equations

Abstract: In this paper, Elzaki Homotopy Perturbation Method is employed for solving linear and nonlinear differential equations with a variable coffecient. This method is a combination of Elzaki transform and Homotopy Perturbation Method. The aim of using Elzaki transform is to overcome the deficiencies that mainly caused by unsatised conditions in some semi-analytical methods such as Homotopy Perturbation Method, Variational Iteration Method and Adomian Decomposition Method. The approximate solutions obtained by means of Elzaki Homotopy Perturbation Method were compared in a wide range of problem's domain with those results obtained by Homotopy Perturbation Method. The comparison shows a precise agreement between the exact solutions and the obtained results by this new method as an applicable one, which needs less computations and is much easier and more convenient than others. So, it can be widely used in engineering and other branches of science.

Study of oil spill on the sea surface in the presence of thermal and concentration buoyancy effects

Abstract: Pollution occurs when the concentration of various chemical or biological con- stituents exceed a level implying negative impact on amenities, the eco-system, resources and human health. Oil spills are the serious environmental hazards which often exhibit long-term impacts. The main objective of response to an oil spill is to reduce its impact on nature and human health. This paper allows us to get a comprehensive idea of the oil spill impact in the presence of thermal and concentration buoyancy eects. The governing equations and their associated boundary conditions are rst cast into dimensionless form and the resulting equa- tions are then solved analytically using perturbation technique. The eect of various physical parameters such as Grashof number, Prandtl number, Schmidt number and chemical reac- tion parameter on the velocity, temperature and concentration prole as well as surface skin friction, heat and coecient of mass transfers are discussed in detail with the help of graphs.

On the stability and threshold analysis of an epidemic model

Abstract: We consider a mathematical model of epidemic spread in which the population is partitioned into five compartments of susceptible S(t), Infected I(t), Removed R(t), Prevented U(t) and the Controlled W(t). We assume each of the compartments comprises of cohorts of individuals which are identical with respect to the disease status. We derive five systems of equations to represent each of the subpopulations. The general stability of the disease free equilibrium (DFE) and the endemic equilibrium states of the linearized model are established using the linear stability theory and the Routh-Hurwitz conditions are established and analyzed in the domain of interest. We find that the DFE is locally asymptotically stable when the infected individuals received ART and use the condom but the endemic state is unstable to initial perturbations. Also, we derive an expression for the basic reproduction number using the next generation matrix approach and find that for R o 1 is unstable.

Approximate algorithm for the multi-dimensional knapsack problem by using multiple criteria decision making

Abstract: In this paper, an interesting and easy method to solve the multi-dimensional knapsack problem is presented. Although it belongs to the combinatorial optimization, but the proposed method belongs to the decision making field in mathematics. In order to, initially efficiency values for every item is calculated then items are ranked by using Multiple Criteria Decision Making (MCDA). Finally, items are selected in according to their rank.

Simulation of Tetracycline onto Graphene Nano Sheet

Abstract: Tetracycline (TC) is a broad spectrum of antibiotic which is used to cure infectious diseases and cancer. It can cause harmful side effects due to its high absorption in all organs. On the other hand graphene is appropriate to carry drug and release it to special target, organ or cell. It may decrease the side effects of the drug dramatically by using low dosage of medicine. Graphene oxide (GO) is able to adsorb the molecule of TC via π-π stacking. Base on this mechanism, simulation of TC molecule onto graphene nano sheets was adjusted. Study of force in the z direction illustrated that TC is closed to graphene via carbon (C 8 ) phenolic ring then it rotates and is again closed to the graphene from amino group side. This case is adsorption equilibrium and total energy of the system is -6800eV.

Certain sufficient conditions for close-to-convexity of analytic functions

Abstract: The object of this paper is to derive certain sucient conditions for close-to- convexity of certain analytic functions dened on the unit disk ∆ := f z 2 C : j zj < 1 g .