On-line GPS Track Simplification Algorithm for Mobile Platforms
R. Ivanov
Key Words:
GPS track simplification; GPS navigation; Kalman filters.
Abstract:
The paper presents an algorithm for on-line simplification of the number of points, describing a GPS track. The proposed algorithm is adaptive to the accuracy of the GPS receiver, the current accuracy of determining the position and the speed of movement. An on-line simplification of the number of track points is offered on the base of analysis of the location of three last points. The degree of reduction of the points is from 3 to 15 times, depending on the track length and trajectory. The errors in the determination of the GPS position are reduced as the values for the latitude and longitude are filtered by an adaptive Kalman filter. The GPS position filtering results in up to 15% additional reduction of number of points in pedestrian mode. r R

Modeling of Multiparty Calls in SIP Networks
E. Pencheva, I. Atanasov
Key Words:
Open access to multiparty call control; SIP session state; labeled transition systems; behavioral equivalence.
Abstract:
In IP-based multimedia networks, Open Service Access (OSA) is an approach to opening network by providing an interface that allows application developers outside the mobile domain to make use of network functionality and to receive information from the network. A Service Capability Server (SCS) is a functional entity that makes OSAstandard interfaces accessible by application and provides an abstraction of network protocol for application developers. As a gateway between applications and the network, the OSA SCS accomplishes mapping of OSA interfaces onto network protocols and vice versa. In the paper, we suggest an approach to modeling OSA SCS behavior in case of third party application control on multimedia sessions. The OSA SCS needs to maintain session state models that correspond both to the application view and Session Initiation Protocol (SIP) used for session management. The approach is described in a formal way using the theory of labeled transition systems. Defining bisimulation relation, we prove the behavioral equivalence between the suggested session state models and those of the standardized multiparty call state models as seen by OSA applications. To illustrate the behavior of OSA SCS, use cases for application control on SIP conferencing are provided.

Method and Algorithm for Interval Maximum Expected Flow in a Network
A. Hossain, G. Gatev
Key Words:
Interval expected flow; interval probability; smallest capacity, uncertainty.
Abstract:
This paper deals with interval maximum expected flow in a capacitated network, when each arc has two parameters: interval probabilities, and capacity. The interval probabilities are uncertain, but lower and upper limits, within which they are expected to fall, are given. A method and algorithm are proposed to determine the maximum interval expected flow in the network.

PID Control Systems with Maximum Gain Margin and Increased Speed Performance
L. Tomov, E. Garipov
Key Words:
PID control; maximum gain margin; two degrees of freedom control; time delay systems.
Abstract:
Novel sub-optimal easy to apply tuning rules for maximum gain margin control are derived for general-form two-degree of freedom (2DOF) PID controllers. As an additional step thus estimated controller parameters are detuned by weighting coefficients for the reference signal in the P and D controller parts according to an extra performance criteria ­ maximum controlled signal speed with no serious changing of the achieved system gain and phase margins. The approximated solutions obtained after optimization and simplification by Symbolic Toolbox of MATLAB are compared with well-known design methods.

Improving the Qualities of SVM Classifiers with Evolutionary Algorithms
V. Nachev, T. Titova, Ch. Damyanov
Key Words:
Pattern recognition; support vector machines; evolutionary algorithms; feature selection; kernel function selection.
Abstract:
This paper concerns the use of evolutionary algorithms for improving the support vector machine (SVM) classification. Method genetic algorithms and genetic programming in the design of an SVM in learning stages: feature selection and kernel function selection are summarized. Experimental results of the SVM method application and adaptation to the recognition of unidimensional spectral realization of potatoes have been presented. In this practical non-destructive quality estimation task, the purpose of this work was to achieve maximum objectivity and accuracy by reducing the heuristic approach to feature selection and kernel SVM classifier synthesis.