bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Distributions of a Renewal Reward Process and It’s Additive Functional
Authors: Khaniyev Tahir , Aliyev Rovshan , Küçük Zafer , Bekar Nurgul
Published: June 2016

In this study, a renewal reward process with a discrete interference of chance
(X(t)) is constructed and distribution of the process X(t) is investigated. One dimensional distribution of the process X(t) is given by means of the probability characteristics of the renewal processes {Tn } and {Sn }. Moreover, one dimensional distribution function of the additive functional Jf(t) of the process X(t) is expressed by the probability characteristics of the initial sequences of the random variables {ξn} and {ηn}.
Fuzzy Decision Support System to Determine Swell/Shrink Factor Affecting Earthwork Optimization of Highways
Authors: Göktepe A. , Lav A. , Altun Selim , Altıntaş Gökhan
Published: June 2016

The optimization of cut and fill volumes of a highway infrastructure is crucial for minimizing the total earthwork cost. Borrow material swells after excavation and shrinks when mechanical compaction is applied; in this respect, it may be misleading to calculate cut-fill volumes directly without considering the amount of swelling and/or shrinkage. On the other hand, determination of such factors characterizing shrinkage/swelling behavior is highly ambiguous. The aim of this paper is to present the applicability of a fuzzy rule-based system for choosing swelling/shrinkage factors affecting the precision of earthwork optimization. This approach may assist in any highway alignment procedure to handle cut and fill volumes more accurately.
Dynamical Control of Accuracy Using the Stochastic Arithmetic to Estimate Double and Improper Integrals
Authors: Fariborzi Araghi Mohammad Ali
Published: June 2016

The CESTAC (Control et Estimation STochastique des Arrondis de Calculs) method is based on a probabilistic approach of the round-off error propagation which replaces the floating-point arithmetic by the stochastic arithmetic. This is an efficient method to estimate the accuracy of the results. In this paper, we present the reliable schemes using the CESTAC method to estimate the definite double integral I = \({\int_a^b}{\int_c^d}\)f(x,y)dydx and the improper integral I = \(\int_a^\infty\)f(x)dx , where a, b, c, d ∈ R, by applying the trapezoidal or Simpson's rule. For each kind of integrals, we prove a theorem to show the accuracy of the results. According to these theorems, one can find an optimal value number of the points which we can find the best approximation of I from the computer point of view. Also, we observe that by using the stochastic arithmetic, we are able to validate the results.
Figure of Merit of One-dimensional Resonant Transmission Systems in the Quantum Regime
Authors: Çipiloğlu Mustafa Ali , Turgut Sadi
Published: June 2016

The figure of merit, ZT, for a one-dimensional conductor displaying a Lorentzian resonant transmission probability is calculated. The optimum working conditions for largest ZT values are determined. It is found that, the resonance energy has to be adjusted to be several resonance widths away from the Fermi level. Similarly it is better for the temperature to be equal to several resonance widths. The approximate relationships, which can be a fairly good guide for designing devices, between different parameters under optimum working conditions are given.
An Approach for Measuring Semantic Relatedness between Words via Related Terms
Authors: Salahli Mehmet
Published: June 2016

In this paper we propose a new approach for measuring semantic relatedness between words. The semantic relatedness between words are not measured directly, but are computed via set of words highly related to them, which we call the set of determiner words. Our approach for evaluating relatedness belongs to web page counting based measurement methods. We take into account some information, which contains hierarchical and other type of relations between the words. The experimental results demonstrate the effectiveness of proposed method.
Motor Input Voltage and Rectifier Firing Angle Variation with Load Torque in Constant Current Operated Induction Motors
Authors: Akbaba M.
Published: June 2016

In current source inverter (CSI) fed induction motors (IM) operated under constant current, the input voltage changes within large limits as the load torque changes. In such an operation the motor mostly operates on the saturated portion of its magnetizing characteristic, and non-linear relation exists between the input voltage and the load torque. Therefore in this paper a numerical technique is presented for obtaining required input voltage corresponding to a given load torque, which can be used for estimating the firing angle of the input rectifier, which in tum can be used for predicting firing angle in terms of load torque. Proposed technique has been demonstrated with an example.
Numerical Modeling of Venturi Flows for Determining Air Injection Rates Using Fluent V6.2
Authors: Baylar Ahmet , Aydin M. , Unsal Mehmet , Ozkan Fahri
Published: June 2016

As the water passes through a restriction in a pipe, it forms a vacuum at the end of the restriction. A hole bored into the pipe at a point where this vacuum occurs will cause air to be drawn into the main flow. One example of this mechanism is seen in the venturi tube. When a minimal amount of differential pressure exists between the inlet and outlet sides of the venturi tube, a vacuum occurs at suction holes of the venturi tube. Venturi aeration is a method of aeration that has become popular in recent years. In present paper, air injection rates of venturi tubes are analyzed using Computational Fluid Dynamics modeling. These analyses are carried out by means of the program FLUENT V6.2 that uses finite volume theory. There is a good agreement between the measured air injection rates and the values computed from FLUENT CFD program.
Designing Optimum Oil Thickness in Artificial Human Knee Joint by Simulated Annealing
Authors: Saruhan Hamit
Published: June 2016

In human knee joints, synovial fluid film covers the surface of synovium and cartilage within the joint space. Synovial joints acts as bearing in mechanical system. Although the artificial human joints differ from most mechanical bearings in their nature, they have been modeled and analyzed in terms of hydrodynamic bearing of engineering. In this study, nature inspired an algorithm, the simulated annealing (SA), is used to find minimum fluid film thickness in artificial human knee joints. It is important to optimize the film thickness of the bearing in terms of successful operation and lifetime of the implant in terms of friction and wear. The problem is complex and a time consuming process due to design variables and constraints imposed on the objective function. It is demonstrated that the SA performed and obtained convergence reliability on the optimum point.
Operating System Selection Using Fuzzy AHP and TOPSIS Methods
Authors: Ballı Serkan , Korukoğlu Serdar
Published: June 2016

The aim of study is developing a fuzzy decision model to select appropriate operating system for computer systems of the firms by taking subjective judgments of decision makers into consideration. Proposed approach is based on Fuzzy Analytic Hierarchy Process (FAHP) and TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) methods. FAHP method is used in determining the weights of the criteria by decision makers and then rankings of the operating systems are determined by TOPSIS method. Empirical study has also been demonstrated.
A Geometrical Optimization Problem Associated with Fruits of Poppy Flower
Authors: Değer Gözde , Pakdemirli Mehmet , Candan Feyza
Published: June 2016

Inspired from the poppy fruit (Papaver rhoeas L.), a geometrical optimization problem is posed. The aim is to minimize the surface area for a given volume. The poppy fruit geometry is selected as the optimization geometry. The mathematical problem is solved using calculus. The optimum solutions obtained from mathematical model are contrasted with measurements of the fruit. A good agreement with difference in areas less than 1% in most of the cases is observed between the results.
Automatic Traffic Density Estimation and Vehicle Classification for Traffic Surveillance Systems Using Neural Networks
Authors: Ozkurt Celil , Camci Fatih
Published: June 2016

It is important to know the road traffic density real time especially in mega cities for signal control and effective traffic management. In recent years, video monitoring and surveillance systems have been widely used in traffic management. Hence, traffic density estimation and vehicle classification can be achieved using video monitoring systems. In most vehicle detection methods in the literature, only the detection of vehicles in frames of the given video is emphesized. However, further analysis is needed in order to obtain the useful information for traffic management such as real time traffic density and number of vehicle types passing these roads. This paper presents vehicle classification and traffic density calculation methods using neural networks. The paper also reports results from real traffic videos obtained from Istanbul Traffic Management Company (ISBAK).
Strength of Wheat and Barley Stems and Design of New Beam/Columns
Authors: Değer Gözde , Pakdemirli Mehmet , Candan Feyza , Akgün Selda , Boyacı Hakan
Published: June 2016

In this study, physical and mechanical properties of wheat and barley stems are examined. Transverse sections of the stems are magnified by a microscope and the material structure in the transverse sections are analysed with image processing programs. Geometric properties such as inner, outer radius, stem wall thickness and density variation of the material along the radius are measured and density variations are approximated by a mathematical model. Moment of inertia of the cross-sectional area which plays a vital role in resistance against bending and buckling is calculated approximately. Using the material density variations of the wheat (Triticum sativum L.) stems, new beam/columns are designed. Stress distributions in this new design and conventional designs of equivalent weight are compared using ANSYS program. It is found that stresses are more uniformly distributed in the new design with maximum stresses being lower than the conventional designs.
A Study for Boronizing Process within Nonextensive Thermostatistics
Authors: Kayacan Özhan , Sahin Salim , Tastan Filiz
Published: June 2016

In this study, diffusion mechanism of the boronizing process of AISI 1040 has been investigated. A nonlinear diffusion equation, which was proposed earlier, has been employed and compared with the experimental data. An interesting property of the diffusion equation used here is that it establishes a connection between the diffusion process and nonextensivity. The theoretical model also exhibits a possible connection between the exponents appeared in the differential equation and the entropic index. In this manner, the possible effects of nonextensivity on the boronizing process have been shown theoretically. We believe that a diffusion equation based on the nonextensive formalism is first applied to the boronizing process in literature.
Free Vibration Analysis of Carbon Nanotubes Based on Shear Deformable Beam Theory by Discrete Singular Convolution Technique
Authors: Demir Çiğdem , Civalek Ömer , Akgöz Bekir
Published: June 2016

In this study, free vibration analysis of carbon nanotubes is investigated based on Timoshenko beam theory. Discrete singular convolution (DSC) method is used for free vibration problem of numerical solution of carbon nanotubes. Numerical results are presented and compared with that available in the literature. It is shown that reasonable accurate results are obtained.
A Design of an Expert System for Selecting Pumps Used in Agricultural Irrigation
Authors: Seflek Ali , Çarman Kazım
Published: June 2016

The economical development of Turkey depends on agriculture so yield in agricultural production has to be increased for improving Turkey’s economy. Irrigation is also very important factor to increase yield per unit area. Different kinds of pumps such as centrifugal, submersible and deep well turbines are used according to the system conditions for irrigation of agricultural areas. It is very difficult to find an expert at desired time and desired place for choosing correct pump which are varied in different kinds and models. In this study, this problem was to be tried to solve by designing of an expert system. The choosing of proper pump is very important because of the plant efficiency.The expert system database was formed by using data obtained from commonly used pumps in Turkey. Flow rate and total manometric head which are important for selecting pump were determined by taking into consideration irrigation area, irrigation methods, water resource, climate, soil properties, crop pattern and well characteristics. The software of expert system was developed for Windows operation system by using Visual Basic Programming Language. In this expert system, when the programme is operated, the trademark/model of pump having the lowest specific energy consumption is determined to be the most suitable pump for the plant at the end of the programme.
Pade Embedded Piecewise Differential Transform Method for the Solution of ODE's
Authors: Çenesiz Y. , Koç A.B. , Çitil B. , Kurnaz A.
Published: June 2016

In this paper Pade Embedded Differential Transformation is proposed for the solution of higher order nonlinear or linear Ordinary Differential Equations (ODE’s). The proposed approach provides a better iterative procedure to find the spectrum of the analytic solutions compared to the classical differential transformation. Illustrative examples are presented to show the preciseness and effectiveness of the proposed method.
Realization of Fuzzy Logic Controlled Brushless DC Motor Drives Using Matlab/Simulink
Authors: Çunkas Mehmet , Aydoğdu Omer
Published: June 2016

In this paper, an efficient simulation model for fuzzy logic controlled brushless direct current motor drives using Matlab/Simulink is presented. The brushless direct current (BLDC) motor is efficiently controlled by Fuzzy logic controller (FLC). The control algorithms, fuzzy logic and PID are compared. Also, the dynamic characteristics of the BLDC motor (i.e. speed and torque) and as well as currents and voltages of the inverter components are easily observed and analyzed by using the developed model.
Calculation of Generalized Level Densities for Nuclei in Mass Region 20 < A < 50
Authors: Babacan H. , Kayacan O.
Published: June 2016

In this study, a relation between generalized level density and standard level density is derived. Using this relation and Bethe formula of Fermi gas model for standart level density we obtained a generalized nuclear level density formula for nucleus. Generalized level densities were calculated for some nuclei in mass region between 20 and 50 for different q values close to 1. Our results explain experimental data better than those of Gilbert-Cameron (GC) and Rohr, which are two of the leading compilations in evaluating nuclear level density.
On the Problem of Wire Rope Model Generation with Axial Loading
Authors: Imrak C. , Erdönmez Cengiz
Published: June 2016

Independent wire rope core (IWRC) is one of the fundamental components of complex wire ropes. It is a complex geometry and constructed by wrapping wire strands over a straight wire strand. The outer wires of the IWRC are double helical shaped feature which can be only modeled using special treatment. The aims of this paper are to introduce a new technique of modeling wire rope with IWRC and to compare numerical results obtained from this model with available results in the literature. Therefore the model generation for a simple straight strand is explained and accuracy of this model is validated. Furthermore this modeling procedure is adapted to whole wire rope structure considering double helical geometry concept. The proposed rope model gives remarkable results by means of wire by wire analysis scheme. This model is found easier and more effective. The results show good agreement with other available results but with a simpler and more practical approach.Independent wire rope core (IWRC) is one of the fundamental components of complex wire ropes. It is a complex geometry and constructed by wrapping wire strands over a straight wire strand. The outer wires of the IWRC are double helical shaped feature which can be only modeled using special treatment. The aims of this paper are to introduce a new technique of modeling wire rope with IWRC and to compare numerical results obtained from this model with available results in the literature. Therefore the model generation for a simple straight strand is explained and accuracy of this model is validated. Furthermore this modeling procedure is adapted to whole wire rope structure considering double helical geometry concept. The proposed rope model gives remarkable results by means of wire by wire analysis scheme. This model is found easier and more effective. The results show good agreement with other available results but with a simpler and more practical approach.
RULES3-EXT Improvements on RULES-3 Induction Algorithm
Authors: Mathkour Hassan
Published: June 2016

This paper describes RULES3-EXT, a new algorithm for inductive learning. It has been developed to cope with some drawbacks of RULES-3 induction algorithm. The extra features of RULES3-EXT are (1) The number of required files to extract a knowledge base (a set of rules) is reduced to 2 from 3 (2) The repeated examples are eliminated, (3) The users are able to change the order of attributes and (4) The system is able to fire rule(s) partially if any of the extracted rules cannot fully be satisfied by an unseen example. The new algorithm has been tested on well known data sets and the efficiency found to be superior to that of RULES-3.
Proposing a New Model on Data Envelopment Analysis by Considering Non Discretionary Factors and a Review on Previous Models
Authors: Jahanshahloo G.R. , Lotfi F. , Shoja N. , Abri A.Gholam , Jelodar M. , Firouzabadi Kamran
Published: June 2016

Discretionary models of data envelopment analysis (DEA) assume that all inputs and outputs are discretionary, i.e., controlled by the management of each decision making unit (DMU) and varied at its discretion. In any realistic situation, however, there may exist exogenously fixed or non-discretionary inputs or outputs that are beyond the control of a DMU's management. There are some models that incorporate non-discretionary inputs into DEA models. This paper reviews these approaches, providing a discussion of strengths and weaknesses and highlighting potential limitations. Moreover, a new method is developed that overcomes existing weaknesses.
Reduced Differential Transform Method for Generalized KdV Equations
Authors: Keskin Yıldıray , Oturanç Galip
Published: June 2016

In this paper, a general framework of the reduced differential transform method is presented for solving the generalized Korteweg–de Vries equations. This technique doesn’t require any discretization, linearization or small perturbations and therefore it reduces significantly the numerical computation. Comparing the methodology with some known techniques shows that the present approach is effective and powerful. In addition, three test problems of mathematical physics are discussed to illustrate the effectiveness and the performance of the reduced differential transform method.
Existence and Uniqueness of Solution of an Uncertain Characteristic Cauchy Reaction-Diffusion Equation by Adomian Decomposition Method
Authors: Rouhparvar H. , Abbasbandy S. , Allahviranloo T.
Published: June 2016

In this paper, the existence and uniqueness theorems for a solution to an uncertain characteristic Cauchy reaction-diffusion problem is studied by Adomian decomposition method. Sufficient conditions are presented for uniform convergence of the proposed method. Also, some illustrative examples are given for solving the problem.
Analytical Aspect of Fourth-Order Parabolic Partial Differential Equations with Variable Coefficients
Authors: Khan Najeeb , Ara Asmat , Afzal Muhammad , Khan Azam
Published: June 2016

In this work, the homotopy analysis method (HAM) is applied to solve the fourth-order parabolic partial differential equations. This equation practically arises in the transverse vibration problems. The proposed iterative scheme finds the solution without any discritization, linearization, or restrictive assumptions. Some applications are given to verify the reliability and efficiency of the method. The convergence control parameter h in the HAM solutions has provided a convenient way of controlling the convergence region of series solutions. It is also shown that the solutions that are obtained by Adomian decomposition method (ADM) and variational iteration method (VIM) are special cases of the solutions obtained by HAM.
Conservation Laws and Invariant Solutions in the Fanno Model for Turbulent Compressible Flow
Authors: Anthonyrajah M. , Mason DP
Published: June 2016

Asymptotic reductions of the Fanno model for one-dimensional turbulent compressible flow of a perfect gas in a long tube are investigated. Conservation laws are derived using the multiplier method for a nonlinear wave equation and a nonlinear diffusion equation for the mean velocity and a nonlinear diffusion equation for the mean pressure. Two conserved quantities for the mean velocity are obtained from the conservation laws and boundary conditions. An invariant solution is derived for the mean velocity using the Lie point symmetries associated with the conserved vector which generated the conserved quantity for the boundary value problem.
Peristaltic Mechanism in an Asymmetric Channel with Heat Transfer
Authors: Hayat T. , Abbasi F.M.
Published: June 2016

This study reports the effects of velocity and thermal slip parameters on the peristaltic motion of variable viscosity and magnetohydrodynamic (MHD) fluid in an asymmetric channel. Heat transfer coefficient and temperature are given due attention with respect to embedded parameters in the problem.
An Analysis of the Symmetries and Conservation Laws of the Class of Zakharov-Kuznetsov Equations
Authors: Kara A.
Published: June 2016

In this paper, we study and classify the conservation laws of the Zakharov- Kuznetsov equations. It is shown that these can be obtained by studying the interplay between symmetry generators and ‘multipliers’. This is, particularly, useful for the higher-order multipliers. As a final note, we include Drinfeld-Sokolov-Wilson system to demonstrate the usefulness of the approach to systems of pdes.
Two-Dimensional Flow in a Deformable Channel with Porous Medium and Variable Magnetic Field
Authors: Matebese B. , Adem A. , Khalique C. , Hayat T.
Published: June 2016

This article is concerned with the analytic solution for a nonlinear flow problem of an incompressible viscous fluid. The fluid is taken in a channel having two weakly permeable moving porous walls. An incompressible fluid fills the porous space inside the channel. The fluid is magnetohydrodynamic in the presence of a time-dependent magnetic field. Lie group method is applied in the derivation of analytic solution. The effects of the magnetic field, porous medium, permeation Reynolds number and wall dilation rate on the axial velocity are shown and discussed.
Group Classification of Coupled Diffusion System with Applications in Soil Science
Authors: Molati M. , Mahomed F.M.
Published: June 2016

We perform a complete group classification of a coupled system of diffusion equations with applications in soil science. The canonical forms of the lowdimensional Lie algebras and the Lie algebras of higher dimension provide a means to specify the diffusion coefficients completely.
A Generalized Cross Validation Method for the Inverse Problem of 3-D Maxwell's Equation
Authors: Ding Liang , Han Bo , Liu Jiaqi
Published: June 2016

The inverse problem of estimation of the electrical conductivity in the Maxwell’s equation is considered, which is reformulated as a nonlinear equation. The Generalized Cross Validation is used to estimate the global regularization parameter and the damped Gauss-Newton is applied to impose local regularization. The damped Gauss-Newton method requires no calculation of the Hessian matrix which is expensive for traditional Newton method. GCV method decreases the computational expense and overcomes the influence of nonlinearity and ill-posedness. The results of numerical simulation testify that this method is efficient.
Parameter Identification for Nonlinear Ill-Posed Problems
Authors: Li Li , Han Bo
Published: June 2016

Since the classical iterative methods for solving nonlinear ill-posed problems are locally convergent, this paper constructs a robust and widely convergent method for identifying parameter based on homotopy algorithm, and investigates this method’s convergence in the light of Lyapunov theory. Furthermore, we consider 1-D elliptic type equation to testify that the homotopy regularization can identify the parameter effectively.
Cylindrical Microparticle Transport and Deposition from Electrokinetic Microflow in a 90 Degree Bend
Authors: Zhang Kai , Huang Lizhong , Nie Deming
Published: June 2016

Cylindrical microparticle transport and deposition from electrokinetic microflow in a 90 degree bend have been numerically simulated. Under the effect of dielectrohporetic force, gravity and stokes force, it’s found that microparticles with larger size deposit on the lower region of the bend’s outer wall. An exponential curve of deposition efficiency versus the product of stokes number and shape factor is fitted based on large number of numerical results.
Nonlinear Dynamic Responses of Arch Dam with Shear Keys
Authors: Du Chengbin , Jiang Shouyan
Published: June 2016

The purpose of this paper is to obtain an insight into the effects of shear keys with different slopes on the nonlinear seismic responses of an arch dam. The nonlinear exponential dynamic contact constitutive model is proposed for simulating the normal interactions of the two surfaces separated by contraction joints, along with the standard Coulomb friction model to simulate the tangential interactions. After the shear key’s real configuration is established, the seismic responses of the arch dam are discussed in detail to understand the effects of shear keys on the behavior of the contraction joints and the stress and deformation of the dam. The results indicate that the dam without the shear keys shows comparatively narrow joint opening, and that the maximum joint opening decreases when the slope of shear keys increases. In addition, the slope of shear keys exerts an obvious effect on the sliding displacement along the radial direction and the stress of the dam.
Effects of Time Delay on Chaotic Neuronal Discharges
Authors: Jin Wuyin , Feng Ruicheng , Rui Zhiyuan , Zhang Aihua
Published: June 2016

Effects of time delay on Hindmarsh-Rose(HR) model neuron are studied. For an individual neuron, with the scaling delay time and synaptic intensity, neuronal firing pattern’s transform among tonic spiking, busting and resting firing state, and the neuronal chaotic spike could be controlled. Furthermore, two coupled HR neuronal system could be fully synchronized under certain coupled strength and delay time.
Nonlinear Transient Analysis for Large-Scale Dynamics of Microelectromechanical Systems with the MOR-PIM Method
Authors: Guan Le , Chu Jinkui , Gao Jiali , Zhang Ran
Published: June 2016

Microelectromechanical Systems (MEMS) is difficult to take transient analysis due to the tight coupling between the multiple energy domains, typically nonlinear. An effective increment-dimensional precise integration method (PIM) combined with the model order reduction (MOR) technique based on Krylov subspace is present to solve large-scale nonlinear finite element dynamics systems. The numerical example of V-beam electro-thermal actuator is shown to demonstrate that the MOR-PIM method can achieve high precision and fast speed when solving the nonlinear dynamic equation with large-scale freedom.
Backward Stochastic Differential Equation on Hedging American Contingent Claims
Authors: Song Ruili , Wang Bo
Published: June 2016

We consider a general wealth process with a drift coefficient which is a function of the wealth process and the portfolio process with convex constraint. Existence and uniqueness of a minimal solution are established. We convert the problem of hedging American contingent claims into the problem of minimal solution of backward stochastic differential equation, and obtain the upper hedging price of American contingent claims.
Application of Hamiltonian Approach to an Oscillation of a Mass Attached to a Stretched Elastic Wire
Authors: Xu Lan
Published: June 2016

This paper applies Hamiltonian approach to a nonlinear oscillation of a mass attached to a stretched wire. Comparison of the obtained results with those of the exact solution shows that the approximate solutions are accurate and valid for the whole solution domain.
Frequency-Amplitude Relationship for Nonlinear Oscillator with Discontinuity
Authors: Zhong Ting , Zhang Jingjing
Published: June 2016

The Hamiltonian approach is used to find an approximate amplitude-frequency relationship of a nonlinear oscillator with discontinuity. The solution procedure is simple while the result is of acceptable accuracy.
The Variational Approach Coupled with an Ancient Chinese Mathematical Method to the Relativistic Oscillator
Authors: Zhou Lin-Hong , He J.H.
Published: June 2016

This paper applies the variational approach to the relativistic oscillator. In order to effectively deal with the irrational term, an ancient Chinese mathematics is introduced. Comparison of the obtained result with the numerical one elucidates the efficiency of the present treatment.
Exact Three-Wave Solutions for the (3+1)-Dimensional Boussinesq Equation
Authors: Li Zheng-Biao
Published: June 2016

In this paper, the three-wave method is used for seeking periodic kink-wave and cross-kink soliton solutions. The (3 + 1)-dimensional Boussinesq equation is chosen as an example to illustrate the effectiveness and convenience the proposed method.
Analytical Solution of Two-Dimensional Viscous Flow Between Slowly Expanding or Contracting Walls with Weak Permeability
Authors: Ganji Z.Z. , Ganji D.D. , Janalizadeh A.
Published: June 2016

In this article the problem of two-dimensional viscous flow between slowly expanding or contracting walls with weak permeability is presented and Homotopy Perturbation Method are employed to compute an approximation to the solution of the system of nonlinear differential equations governing the problem. Comparisons are made between the Numerical solution (NM) and the results of the He's Homotopy Perturbation Method (HPM). The results reveal that these methods are very effective and simple and can be applied for other nonlinear problems.
Analytical Solutions of Nano Boundary Layer Flows by Using He's Homotopy Perturbation Method
Authors: Khaki M. , Ganji D.D.
Published: June 2016

The aim of this article is to examine nano boundary layer. The equations governing the flow on wedge are derived from continuity and Navier-Stoks equations. The boundary conditions for the governing equations are obtained from the nonlinear Navier slip condition. This boundary condition contains an arbitrary index parameter, denoted by n > 0, which appears in the coefficients of the ordinary differential equation to be solved. The coupled equations are transformed into one differential equation by similarity solution. The transformed equation is then solved by He’s Homotopy perturbation method and an analytical solution will be achieved. The validity of results is verified by comparing results with existing numerical results. Results are presented for the x and y components of the velocity profiles. Results are in reasonable agreement with those provided by other numerical methods and demonstrate a good accuracy of the obtained analytical solutions.
Searching for the Shortest Path Through Group Processing for TSP
Authors: Meşecan İbrahim , Bucak İhsan , Asilkan Özcan
Published: June 2016

Thanks to its complexity, Traveling Salesman Problem (TSP) has been one of the most intensively studied problems in computational mathematics. Although many solutions have been offered so far, all of them have yielded some disadvantages and none has been able to claim for the best solution. We believe that better solution could be obtained through iterative evaluations, until a certain number of islands are reached, if we could develop an algorithm which grows geometrically. Some algorithms have suggested random solutions and many suggested using the closest neighbors. In many cases islands exist in groups or chains in any length. Therefore they can be connected to any other island rather than the closest one. This can be better identified when we spot out the patterns and island chains. In this paper, we have searched for the identification of patterns and chains. We propose an iterative Group Processing (GP) approach which finds better paths in the 90% of the cases overall as we compare it to Random Logic (RL) programs and most up-to-date Artificial Neural Network based TSP programs.
Technical Efficiency and Total Factor Productivity Growth in the Hazelnut Agricultural Sales Cooperatives Unions in Turkey
Authors: Candemir Mehmet , Özcan Mümin , Güneş Mustafa , Deliktaş Ertuğrul
Published: June 2016

This study measures the production efficiencies and total factor productivity changes of Hazelnut Agricultural Sales Cooperatives Unions (HASCUs) in Turkey over the period 2004-2008. Turkey produces %78.2 hazelnut production of world and gives service to 233,820 farmers in the Black Sea Region of Turkey. To measure production efficiencies of these units, Data Envelopment Analysis (DEA) Approach and Malmquist Productivity Indexes are used. In the our efficiency analysis, the data of 50 HASCUs is considered but only the data of 37 cooperative units is found appropriate for the DEA. The findings of our study show that the average annual technical efficiency scores of HASCUs change between 0.841 and 0.938. It has also been observed that there are average annual %1.3 improvements in technical efficiency, 3% regress in technical change, and %1.7 decreases in the total factor productivity of the HASCUs over the period 2004-2008.
Optimization of Open Canal Cross Sections by Differential Evolution Algorithm
Authors: Turan Mustafa , Yurdusev Mehmet
Published: June 2016

Open canals are important water transfer structures used in water resources systems. As such, they may require substantial amount of investment depending on its length and cross section. Therefore, cross section design should be carried out on an optimization basis. Traditionally, optimal sizing of open canal cross sections are undertaken by nonlinear optimization techniques such as Lagrange Multipliers. In this study, optimum cross sections of different canal geometries are obtained using differential evolution algorithm and the findings of these exercises are compared with those of given in related literature. It is observed that differential evolution algorithm can be well applicable to the problem and capable of giving the global optima.
Numerical Investigation of Residual Stresses in YBCO/CeO2/YSZ/CeO2/Ni Architextured Materials for Coated Conductors
Authors: Toparli Mustafa , Sayman Onur , Celik Erdal
Published: June 2016

In this study, the stress analysis of YBCO/CeO2/YSZ/CeO2/Ni architextured materials under cryogenic conditions was carried out for coated conductor applications. YBCO/CeO2/YSZ/CeO2 multilayer films were fabricated on Ni tape substrate using reel-to-reel sol-gel and Pulse Laser Deposition (PLD) systems. The microstructural evolution of high temperature superconducting YBCO film and buffer layers with CeO2/YSZ/CeO2 configuration grown on textured Ni tape substrates were investigated by a Scanning Electron Microscope (SEM). SEM observations revealed that crack-free, pinhole-free, continuous superconducting film and buffer layers were obtained by solgel and PLD systems. The thermal distribution in the each layer was calculated using the classical lamination theory in the temperature range of 25 to -270°C in liquid helium media. The residual stresses occurred during the manufacturing are neglected therefore, all the residual stresses are assumed to be zero at 25°C. Different thermal expansion coefficients and modulus of elasticity bring about the thermal stresses in the layers.
A Model for the Calculation of Mechanical Properties of Hydroxyapatite Coatings on Ti6Al4V Substrate Using Finite Element Methods
Authors: Pasinli Ahmet , Culha Osman , Celik Erdal , Toparli Mustafa
Published: June 2016

The scope of this study is to find out yield curve on the coating-substrate system of hydroxyapatite (HA) by finite element modeling. With this regard, Hydroxyapatite (HA) coatings were successfully formed on Ti6Al4V substrates by using biomimetic technique. Experimental indentation tests were conducted on Dynamic Ultra-micro Hardness test machine. In finite element modeling (FEM), mechanical properties of coatings were determined by using ABAQUS software package. This numerical study was carried out using an axisymmetric FEM model. To calculate the mechanical properties of coating, the resulting load–unload test data of the samples obtained from the experimental indentation tests were analyzed and curvefitted in Kick’s and Meyer’s law for the loading and the unloading part of the loadunload curve respectively. Then, a set of analytical functions that take the pile-up and sink-in effects into account during instrumented sharp indentation were solved using numerical methods These analytical functions were defined within an identified representative plastic strain, εr, for the Vickers indenter geometry as a strain level that allows for the description of the indentation loading response independent of strain hardening exponent, n.
Investigation of Coating Layer to Reduce Thermal Stresses in Steel Fiber Reinforced Aluminum Metal Matrix Composite
Authors: Okumuş Fuat
Published: June 2016

In this study, by using coating layers to reduce thermal stresses in the metal matrix composites with a mismatch in coefficients of thermal expansions of fiber and matrix is investigated. The thermoelastic solutions based on a three cylinder model are deformed. It is shown that the effectiveness of the layer can be defined by the product of its cofficients of thermal expansions and thickness and that a compensating layer with a sufficiently high coefficient of thermal expansions can reduce the thermal stresses in the metal matrix. . In order to verify the results were compared with the finite element method. In this solution, 224 nodes and 44 nine-node isoparametric elements are used. The study is based on a three cylinder model isolating one steel fiber with a coating layer and a aluminum matrix layer. Only monotonic cooling is studied and the variation of the material properties with temperatures is not considered. The results have been presented in graphics.
Non-Ergodic to Ergodic Regime Transition via Intrusions in a Non-Poisson Renewal System with Power Law Tails
Authors: Akin Osman
Published: June 2016

We study the effect of non-linear perturbations in the form of periodic intrusions in the case of a non-Poisson renewal system in the non-ergodic regime. We notice that, intrusions may cause the system to shift the power index and may even cause a transition from a non-ergodic regime to an ergodic regime. We have made the diffusion entropy analysis (DEA) of the system and notice that the change of the degree of complexity is consistent with the transition as well.
Optimal Lot Sizing with Scrap and Random Breakdown Occurring in Backorder Replenishing Period
Authors: Ting Chia-Kuan , Chiu Yuan-Shyi , Chan Chu-Chai
Published: June 2016

This paper is concerned with determination of optimal lot size for an economic production quantity model with scrap and random breakdown occurring in backorder replenishing period. In most real-life manufacturing systems, generation of defective items and random breakdown of production equipment are inevitable. To deal with the stochastic machine failures, production planners practically calculate the mean time between failures (MTBF) and establish the robust plan accordingly, in terms of optimal lot size that minimizes total production-inventory costs for such an unreliable system. Random scrap rate is considered in this study, and breakdown is assumed to occur in the backorder filling period. Mathematical modeling and analysis is used and the renewal reward theorem is employed to cope with the variable cycle length. An optimal manufacturing lot size that minimizes the long-run average costs for such an imperfect system is derived. Numerical example is provided to demonstrate its practical usages.
A Novel Method for Multiple Attribute Decision-Making of Continuous Random Variable under Risk with Attribute Weight Unknown
Authors: Liu Peide
Published: June 2016

The extension of the fuzzy TOPSIS method based on the combination weight is presented to deal with multiple attribute decision-making problems under risk where the attribute value takes the form of the continuous random variable on the bounded intervals. First, the risk decision matrix is normalized by the transformation of the density function, and the variation coefficient method is used to determine the objective weights based on the expectations of the random variables. Subsequently, according to the maximizing rule of the weighted synthetic value of alternatives, the synthetic weight model is established. Then, the ideal solution and negative ideal solution is defined, the distances between the alternatives and the ideal/negative ideal solutions, and the relative closeness coefficients are calculated. In addition, the alternatives are ranked by the relative closeness coefficient of the alternatives. Finally, an illustrative example with the interval number is given to demonstrate the steps and the effectiveness of the proposed method.
A Method for Ranking of Fuzzy Numbers Using New Weighted Distance
Authors: Allahviranloo T. , Abbasbandy S. , Saneifard R.
Published: June 2016

In this paper, the researchers proposed a modified new weighted distance method to rank fuzzy numbers. The modified method can effectively rank various fuzzy numbers, their images and overcome the shortcomings of the previous techniques. The proposed model is studied for a broad class for fuzzy numbers and class of functions the membership of which is formed on the basis of the template ( ) max (0.1 ) s  x   x . This article also used some comparative examples to illustrate the advantage of the proposed method.
An Improved Vogel's Approximation Method for the Transportation Problem
Authors: Korukoğlu Serdar , Ballı Serkan
Published: June 2016

Determining efficient solutions for large scale transportation problems is an important task in operations research. In this study, Vogel’s Approximation Method (VAM) which is one of well-known transportation methods in the literature was investigated to obtain more efficient initial solutions. A variant of VAM was proposed by using total opportunity cost and regarding alternative allocation costs. Computational experiments were carried out to evaluate VAM and improved version of VAM (IVAM). It was seen that IVAM conspicuously obtains more efficient initial solutions for large scale transportation problems. Performance of IVAM over VAM was discussed in terms of iteration numbers and CPU times required to reach the optimal solutions.
The Effects of Temperature and Thermal Stresses on Impact Damage in Laminated Composites
Authors: Benli Semih , Sayman Onur
Published: June 2016

The aim of this study is to investigate the effects of temperature and thermal residual stresses on the impact behavior and damage of unidirectional glass/epoxy laminated composites. To this end, thermal stress analyses of the laminates with lay-ups [90/0/0/90]s, [90/0/45/45]s, [0/90/45/-45]s were carried out under temperatures of 20, 90 and -50 °C by using ANSYS software. Damage parameters proposed by Hou et al. [13] were used for failure analyses. Also, the impact tests on the laminated composites were performed at the impact energies ranging from 5 J to 55 J under the mentioned temperatures. The specific energy values and impact parameters were obtained and compared for each type of specimens and temperatures. The results obtained from both thermal stress analyses and impact tests indicated that the contribution of thermal stresses to impact damage increases with decreasing temperature and therefore, the stresses at low temperatures have a significant effect on the impact damage and parameters of unidirectional laminated composites.
Evaluation of Optimal Sensor Placement Techniques for Parameter Identification in Buildings
Authors: Bakir Pelin
Published: June 2016

This paper addresses the application of six different optimal sensor placement (OSP) techniques in buildings. These techniques are the EFfective Independence (EFI), Optimal Driving Point (ODP), Non-Optimal Driving Point (NODP), Effective Independence Driving Point Residue (EFI-DPR), Singular Value Decomposition (SVD) and the Sensor Set Expansion (SSE) methods. A toolbox OPTISEP is developed by the author for this purpose within the context of this paper. The techniques are compared among themselves by using various criteria. The overall results show that the SSE Technique is the best. First, the technique results in a dramatic reduction in the computational effort. Second, it allows a civil engineer to specify a set of locations that they absolutely want to keep in the final sensor configuration. Mozst importantly, while the sensor distribution estimated by other techniques is mainly concentrated in a certain storey of the building, SSE gives a homogeneous sensor distribution throughout the building. Finally, it is shown that the technique i s also robust against noise in the measurements.
The Differential Transformation Method and Pade Approximant for a Form of Blasius Equation
Authors: Peker Haldun , Karaoğlu Onur , Oturanç Galip
Published: June 2016

Boundary conditions in an unbounded domain, i.e. boundary condition at infinity, pose a problem in general for the numerical solution methods. The aim of this study is to overcome this difficulty by using Padé approximation with the differential transform method (DTM) on a form of classical Blasius equation. The obtained results are compared with, for the first time, the ones obtained by using a modified form of Adomian decomposition method (ADM). Furthermore, in order to see the consistency of solutions, they are also compared with the ones obtained by using variational iteration method (VIM).