Mathematical and Computational Applications

1540 KiB

Open AccessArticle

On some Extensions of Dynamical Homeomorphism and Dynamical Isomorphism in Dynamical System

by Necdet Bildik and Mustafa İnç

Math. Comput. Appl. 1999, 4(2), 189-194; https://doi.org/10.3390/mca4020189 - 01 Aug 1999

Viewed by 1164

In this paper, the definitions and the theorems concerning with the invariant sets, w- and α- limit sets are given and proved in the new Dynamical Systems. By using of the definition of P and P^¯ stability, some remarkable unknown results are [...] Read more.

In this paper, the definitions and the theorems concerning with the invariant sets, w- and α- limit sets are given and proved in the new Dynamical Systems. By using of the definition of P and P^¯ stability, some remarkable unknown results are obtained. Finally, the definition of Dynamical Isomorphism and Dynamical Homeomorphism are given and related original theorems are presented and proved. Full article

1232 KiB

Open AccessArticle

An Effective Algorithm for Euler System in a Class of Discontinuous Functions

by M. Rasulov and E. Coşkun

Math. Comput. Appl. 1999, 4(2), 185-188; https://doi.org/10.3390/mca4020185 - 01 Aug 1999

Viewed by 1162

Abstract

n/a Full article

3592 KiB

Open AccessArticle

An Approach to the Support of the Fault-Tolerance of the Double Redundant Computer Control Systems

by Rafig Samedov

Math. Comput. Appl. 1999, 4(2), 175-184; https://doi.org/10.3390/mca4020175 - 01 Aug 1999

Cited by 2 | Viewed by 1182

Abstract

Faults in computer control systems cause great economic losses and endanger human beings. In order to ensure control and monitoring tasks, the availability and safety of computer control systems in areas such as military, manufacturing plants, traffic, public health service, environment protection, banking [...] Read more.

Faults in computer control systems cause great economic losses and endanger human beings. In order to ensure control and monitoring tasks, the availability and safety of computer control systems in areas such as military, manufacturing plants, traffic, public health service, environment protection, banking and assurances have to be improved. The fault-tolerance of the computer control system is achieved by using the hardware and software redundancy and redundancy of processor time. In this paper, the structure of real time double redundant computer control system is updated. The highly efficient methods and device are designed for supporting of the fault-tolerance of the double redundant computer control system by using the hardware redundancy. The fault-tolerant system software enables identical application programs to work parallel on two reserved computers. The computational process executed in a computer control system is periodically interrupted at checkpoints by execution of the fault-tolerant procedure, which recognizes and eliminates the faulty computers. The recovery of computer control system is automatically without interruption of the control services.
Full article

1946 KiB

Open AccessArticle

Optimal Trajectory Determination for Sagitally Symmetric Manual Lifting Tasks

by Omer Gundogdu and Kurt S. Anderson

Math. Comput. Appl. 1999, 4(2), 169-174; https://doi.org/10.3390/mca4020169 - 01 Aug 1999

Viewed by 1063

Abstract

A two dimensional, multi-link sagittally symmetric whole-body model was developed to simulate an optimal trajectory for manual material lifting. Non-linear optimal control techniques and genetic algorithms were utilized in the simulations to explore practical lifting patterns. The simulation results were then compared with [...] Read more.

A two dimensional, multi-link sagittally symmetric whole-body model was developed to simulate an optimal trajectory for manual material lifting. Non-linear optimal control techniques and genetic algorithms were utilized in the simulations to explore practical lifting patterns. The simulation results were then compared with the experimental data. Full article

2418 KiB

Open AccessArticle

On the Drag Force of a Solid Sphere in Power Law Flow Model

by T. Ahbasov, S. Herdem and A. Memnedov

Math. Comput. Appl. 1999, 4(2), 161-167; https://doi.org/10.3390/mca4020161 - 01 Aug 1999

Viewed by 1024

Abstract

A theoretical approach for estimation of the drag correlation coefficients in the flow of Newtonian or weak non-Newtonian liquids around spherical solid particles is presented. Some new analytical relations are derived by using a modified stream function. It is shown that these relationships [...] Read more.

A theoretical approach for estimation of the drag correlation coefficients in the flow of Newtonian or weak non-Newtonian liquids around spherical solid particles is presented. Some new analytical relations are derived by using a modified stream function. It is shown that these relationships can be applicable in a wide range of Reynolds number, up to Re < 1000 for the liquids with a flow behaviour index, n, in the range of 0.5<n<1. The predicted coefficients from these relationships are in very good agreement with the experimental data given in the literature. Full article

1930 KiB

Open AccessArticle

Multi-Objective Optimization for Design and Stability of a General Control System

by Murat Makaracı

Math. Comput. Appl. 1999, 4(2), 153-159; https://doi.org/10.3390/mca4020153 - 01 Aug 1999

Viewed by 946

Abstract

With the advancement of new materials and techniques, smooth and high performance operation of critical systems such as fight simulators, satellite navigators and robots arms are desired in these systems, often more than one objective has to be accomplished. In the present study, [...] Read more.

With the advancement of new materials and techniques, smooth and high performance operation of critical systems such as fight simulators, satellite navigators and robots arms are desired in these systems, often more than one objective has to be accomplished. In the present study, the global criterion method is used as the multi-objective optimization tool. A general mass-spring-dashpot system is analyzed. Damping ratio and natural frequency are chosen as design variables. System settling time, percent overshoot and time to reach to maximum peak are objective functions to be minimized. Numerical solutions with the given constraints are presented and design specifications for the control system are suggested. It is also shown that this optimization tool is a good candidate for multi-criterion problems. Full article

2504 KiB

Open AccessArticle

Some Results on a Stochastic Process with a Discrete Chance Interference

by T. A. Khaniev

Math. Comput. Appl. 1999, 4(2), 145-152; https://doi.org/10.3390/mca4020145 - 01 Aug 1999

Viewed by 1203

Abstract

In this study, some problems connected with stochastic process with a discrete chance interference X(t) are investigated. In particular, one-dimensional distribution functions of the process are obtained and under some weak assumptions, the ergodic theorem for this process is given. As a result, [...] Read more.

In this study, some problems connected with stochastic process with a discrete chance interference X(t) are investigated. In particular, one-dimensional distribution functions of the process are obtained and under some weak assumptions, the ergodic theorem for this process is given. As a result, the explicit form of ergodic distribution function is derived. Moreover, the double transform of distribution function of additive functional of the process X(t) is derived. Furthermore, asymptotic behaviour of the additive functional is investigated as t→∞. Based on these results characteristic function of ergodic distribution of the process X(t) is obtained by using a joint distribution of random variables N and S_N. In addition, the first and second moments of ergodic distribution of X(t) are expressed in terms of the moments of random variable N. Full article

2066 KiB

Open AccessArticle

Error Analysis of Determining Airplane Location by Global Positioning System

by Chingiz Hajiyev and Alper Burat

Math. Comput. Appl. 1999, 4(2), 137-144; https://doi.org/10.3390/mca4020137 - 01 Aug 1999

Viewed by 935

Abstract

This paper studies the error analysis of determining airplane location by global positioning system (GPS) using statistical testing method. The Newton Rhapson method positions the airplane at the intersection point of four spheres. Absolute errors, relative errors and standard deviation have been calculated [...] Read more.

This paper studies the error analysis of determining airplane location by global positioning system (GPS) using statistical testing method. The Newton Rhapson method positions the airplane at the intersection point of four spheres. Absolute errors, relative errors and standard deviation have been calculated The results show that the positioning error of the airplane varies with the coordinates of GPS satellite and the airplane. Full article

5887 KiB

Open AccessArticle

Advanced Signal Processing Techniques for Faulth Diagnostics-a Review

by Şeref Naci Engin, Kayhan Gülez and M. N. M. Badi

Math. Comput. Appl. 1999, 4(2), 121-136; https://doi.org/10.3390/mca4020121 - 01 Aug 1999

Cited by 4 | Viewed by 1353

Abstract

An overview of major signal processing and analysis methods finding an area of application in machinery fault diagnostics is presented. Among them Wavelet Transform, which has been gaining a special interest in many research and engineering fields, is emphasized with an example application [...] Read more.

An overview of major signal processing and analysis methods finding an area of application in machinery fault diagnostics is presented. Among them Wavelet Transform, which has been gaining a special interest in many research and engineering fields, is emphasized with an example application based on numerically obtained vibration-time data representing various health conditions of a spur gear. Full article

2366 KiB

Open AccessArticle

Peristaltic Flow of a Third-Grade Fluid in a Planar Channel

by F. T. Akyıldız, H. Demir and V. S. Ertürk

Math. Comput. Appl. 1999, 4(2), 113-120; https://doi.org/10.3390/mca4020113 - 01 Aug 1999

Cited by 6 | Viewed by 1100

Abstract

The problem of peristaltic transport of a non-Newtonian fluid represented by the constituve equation for a third grad fluid was analysed for the case of planar channel with harmonically undulating extensible wall, under zero Reynolds number and long wavelength approximation. New exact analytical [...] Read more.

The problem of peristaltic transport of a non-Newtonian fluid represented by the constituve equation for a third grad fluid was analysed for the case of planar channel with harmonically undulating extensible wall, under zero Reynolds number and long wavelength approximation. New exact analytical solution of the non-linear equation resulting from the momentum equation was given when γ₂ + γ₃(which are the dimensionless material constants)>0 and under some conditions when γ₂ + γ₃<0. Also, the exact range of validity of the perturbation analysis was obtained using the Girolamo Cardano formulas and binomial theorem for both γ₂ +γ₃>0 and γ₂+ γ₃<0. Finally, we have shown that pumping rate of a third-grade fluid can be greater or less than for a Newtonian fluid having a shear viscosity same as the lower-limiting viscosity of non-Newtonian material depending on the value of the material constants, amplitude ratio and flow rate.n/a Full article

1709 KiB

Open AccessArticle

The Sensitivity of Halo Nuclei to the Nuclear Radius

by Şeref Okuducu, Güneş Tanır and Başar Şarer

Math. Comput. Appl. 1999, 4(2), 107-111; https://doi.org/10.3390/mca4020107 - 01 Aug 1999

Viewed by 901

Abstract

β-decay provides important information about the structure of halo nuclei. Because of the root-mean-square radius (R_rms) of the neutron halo distribution is very large, the phase-space factor for halo nuclei must be more sensitively depended on the radius. In this work [...] Read more.

β-decay provides important information about the structure of halo nuclei. Because of the root-mean-square radius (R_rms) of the neutron halo distribution is very large, the phase-space factor for halo nuclei must be more sensitively depended on the radius. In this work the sensitivity of the nuclear radius to the phase-space factor was investigated for some halo nuclei and the improvement for phas-space factor for halo nuclei was reported. The results wrere applied to calculate the logft-values for the halo nuclei(⁶He, ⁸He, ¹¹Be, ¹⁴Be, ⁹Li, ¹¹Li). The modification proposed shows reasonable results for many casesn/a Full article

2564 KiB

Open AccessArticle

Fragmentation of a Non-Rotating Ni19 Cluster: A Molecular Dynamics Study

by Halil Avcı, Mehmet Çivi, Ziya B. Güvenç and Julius Jellinek

Math. Comput. Appl. 1999, 4(2), 99-106; https://doi.org/10.3390/mca4020099 - 01 Aug 1999

Viewed by 1009

Abstract

Collisionless fragmentation of a non-rotating Ni₁₉ cluster is studied using constant-energy molecular dynamics computer simulations. The cluster is modelled by an embedded atom model (EAM) energy surface. Distribution of the channel-specific fragmentation probabilities, and global rate constants are computed and analyzed as [...] Read more.

Collisionless fragmentation of a non-rotating Ni₁₉ cluster is studied using constant-energy molecular dynamics computer simulations. The cluster is modelled by an embedded atom model (EAM) energy surface. Distribution of the channel-specific fragmentation probabilities, and global rate constants are computed and analyzed as functions of the internal energy of the cluster. The results are compared with those obtained using the RRK statistical approach, and also compared with the other multi-channel fragmentation work. Full article

2097 KiB

Open AccessArticle

On the Principal Component Based Fingerprint Classification Using Directional Images

by Meltem Ballan and Fikret Gurgen

Math. Comput. Appl. 1999, 4(2), 91-97; https://doi.org/10.3390/mca4020091 - 01 Aug 1999

Cited by 3 | Viewed by 1147

Abstract

This study presents a method for fingerprint recognition based on principal component analysis (PCA) and point patterns (minutae) obtained from the directional histograms of a fingerprint. We first employ Principal Component Analysis (PCA) method to compress fingerprint data. The compressed data are then [...] Read more.

This study presents a method for fingerprint recognition based on principal component analysis (PCA) and point patterns (minutae) obtained from the directional histograms of a fingerprint. We first employ Principal Component Analysis (PCA) method to compress fingerprint data. The compressed data are then used for directional image representation. After the compressed data are obtained, the process continues with directional image formation, directional image block representation, and fingerprint matching, respectively. Our method determines the direction of each pixel, process the images in blocks and uses directional histograms thus removes the need for thinning. The method gives the same performance as that of the uncompressed data, but reduces computation. Furthermore, the parts of the system that successfully use artificial neural networks (ANN) are mentioned. Full article

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Math. Comput. Appl., Volume 4, Issue 2 (August 1999) – 13 articles , Pages 91-194

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