Daneshvar Medicine: Basic and Clinical Research Journal
Year:2003 | Volume:10 | Issue:43|Papers Count:9

There are various methods to treat degeneracy in Monte Carlo simulation. Lugli-Ferry method is a more precise method, which is also compatible with Monte Carlo simulation. However, it has shown that the Lugli-Ferry method creates a non-physical behavior in average energy characteristic, at low fields. A new method has already proposed to overcome this problem in a 1-D bulk region. In this article, we present a mathematical and numerical technique to improve the proposed method, useful for 2-D Monte Carlo simulation of semiconductor devices.

In this paper we consider the problem of Measuring Cerebral Blood Flow (CBF) from Perfusion Magnetic Resonance Images. A method for calculating the minimum of the MR signal is proposed, which is used in determining the thresholds of the Singular Value Decomposition method of measuring CBF. Application of Spline in smoothing the concentration-time curves is also considered, which can be used in calculating the Cerebral Blood Volume (CBV). In analyses of real clinical data, the Arterial Input Function (AIF) was extracted from the concentration-time curves of the volume of interest (VOI). At the end of the paper, Perfusion Maps resulted from the analyses of real clinical data are displayed.

One of the image processing applications is feature extraction for recognition purposes. Due to the fact that neonate has been in amniotic fluid inside mother's uterus at least for six month, upon birth, would have no fingerprints recognizable. So to clearly recognize a neonate, footprint pattern can be used. This pattern consists of lines in different directions and in some position contains cross lines. In this paper, for each right footprint image of neonate, these lines after brightening, by using Radon Transformation would be recognized and with clustering in the Radon space, lines with higher value would be selected and then in spatial space it would be back projected along with initial brightened image. At the end, by using Eucleadin distance of points according to lines in the Radon space an unknown image among the existing images in the bank would be recognized. To the best knowledge of the authors, this research is first being carried out on neonate footprint and usage of some new algorithms of feature extraction, this proposed method can be used by relevant institute for recognition.

In this paper a distributed algorithm for load balancing in cellular mobile systems, which is based on probabilistic cellular automata, is presented. The proposed algorithm unlike existing algorithms provides higher degree of independence for each cell of cellular systems for decision-making. Simulations results show that the proposed algorithm performs well under medium load.

One of the important tools has been recognized to identify patterns is the neural networks and the authors have investigated the application of PLN in this article. This structure was recommended in 1989 and it's capability for simultaneously saving of each pattern, was surveyed. For training this structure, a method called "A-Learning rule" is recommended and also convergence analysis is investigated. Training of the mentioned structure. "A-Learning rule" and "On-Line genetic algorithm (OGA)" premier presented by authors, are used for saving 0-9 Latin digit. Higher convergence speed and capability of saving space of the OGA in compare to the A-learning rule on the PLN, are the results of this article.

This paper presents two new approaches suitable for stability analysis of linguistic models. Many authors considered stability analysis of fuzzy TSK model and used classical approaches for stability analysis  believe these approaches have conflict with the simplicity idea, which is the corner stone's of fuzzy logic methodologies. Simplicity in system modeling and system analysis was the main reason for linguistic modeling offered by professor Zadeh. Some authors touch the problem of linguistic fuzzy stability analysis but it is still an open problem. This paper presents the above methodologies with some definitions and a necessary and sufficient condition for stability of a class of linguistic fuzzy system. This stability analysis is verified using some benchmark systems simulations.

In this paper Linear Quadratic Control (LQR) for 2-D systems is considered .By transferring a 2-D system to 1-D Wave Advanced Model (WAM) the theory available for 1-D LQR problem will be extended to 2-D systems. Then the final results will be held in the initial 2-D system's format. In this case some numerical difficulties will be discussed. As a secondary matter, results will be used for large scale 1-D systems as well.

Nowadays medical images have become an important part of the medical diagnosis. This fact, and also the extreme capacity these images need to be digitally saved and stored in hospital, has made "image compression" a gold topic in recent researches. In this article, we have studied fractal image compression and have introduced an enhanced version of it for the aforementioned usage. The modification made, which we have named it "Improved Adaptive Iterated Function System (lAPIFS)", has enhanced the quality of the reconstructed images, has increased the speed of coding and also has improved the compression rate.