The Tongue Display Unit (TDU) is a 144-channel programmable pulse generator that delivers dc-balanced voltage pulses suitable for electrotactile (electrocutaneous) stimulation of the anterior-dorsal tongue through a matrix of surface electrodes. This article reviews the theory of operation and design overview of the TDU, as well as selected applications. These include sensory substitution, tactile information display, and neurorehabilitation via induced neuroplasticity. Keywords electrotactile

electrocutaneous
tactile display
tongue
electrode
sensory substitution
neuromodulation
neurorehabilitation
neuroplasticity
platform technology

Magnetic resonance electrical impedance tomography (MREIT) aims to produce cross-sectional images of conductivity distributions inside animal and human subjects. In this study, we validate its feasibility by performing conductivity imaging experiments of post-mortem canine bodies. After clipping the hair of a beagle, we attached four carbon-hydrogel electrodes and placed the dog inside our 3T MRI scanner. We injected imaging current in a form of short pulses into the imaging area, of which timing was synchronized with a chosen pulse sequence. Obtaining images of induced magnetic flux density distributions inside the dog, we reconstructed conductivity images using the single-step harmonic Bz algorithm based on the relation between the conductivity and the magnetic flux density. Reconstructed conductivity images of the heart, kidney, prostate, and other organs exhibit unique contrast information which is hardly observed in other imaging modalities. Providing cross-sectional conductivity images with a spatial resolution of a few millimeters, MREIT may deliver unique new diagnostic information in its future clinical studies. Key words: MREIT, magnetic flux density, conductivity image, canine body, harmonic Bz

Multiple ablation technologies are used to provide atrial fibrillation therapy during cardiac surgery. A rigorous search was performed to identify all peer-reviewed papers that provided clinical outcomes data following the ablation therapy. A META analysis showed significant differences in clinical outcomes by ablation technology type: clinicians using temperature-controlled RF power delivery achieved higher rates of normal sinus rhythm at follow-up and patients ablated with microwave ablation had lower rates of normal sinus rhythm than the average of all ablation-treated patients. Permanent pacemaker implantation rates were higher than average for patients treated with microwave or argon-based Cryoablation technologies, but were lower than the average for patients treated using temperature-controlled RF. Key words: Cardiac Surgery

Ablation Technology
Atrial Fibrillation
META Analysis
COX Maze

For monitoring pulmonary edema secondary to congestive heart failure (CHF), we investigated trends of impedance between implanted electrodes. Methods: ICDs were implanted in 16 dogs and 5 sheep. Right ventricles were paced (230-250 bpm) for several weeks. Impedance was measured every hour along 4 intrathoracic, 2 intracardiac and 4 cardiogenic vectors. Cardiac function was assessed biweekly by catheterization and echocardiography. Left atrial pressure (LAP) was measured daily by an implanted sensor. Results: All animals developed CHF after 2-4 weeks of pacing (EF, 52 vs. 34%

LVEDV, 65 vs. 97 ml
LVEDP, 7 vs. 16 mmHg
LAV, 17 vs. 33 ml
LAP, 7 vs. 26 mmHg). Impedance decreased during CHF: LV-Can, 17±9%
LV-RV, 15±8%
LV-RA, 13±6%
RV-Can, 13±8%
RVcoil-Can, 8±6%
RA-Can, 6±6%. The LV-Can decrease was greatest and correlated well with LAP (r2=0.73). All impedances were associated with circadian variability at baseline which diminished during CHF (5±2% vs. 2±1%). In CHF, cardiogenic impedances displayed reduced peak-to-peak amplitude and increased fractionation. Conclusions: As impedance decreased during CHF, left-heart trends were better correlated with LAP. Left-heart vectors may improve detection of CHF compared to sensing by right-heart leads alone. This approach has important clinical implications for managing HF patients in ambulatory settings. Keywords  Impedance, Heart Failure, Edema, Pacemaker, Defibrillator

With increasing use of data transmission between digital systems as well as subsystems, the need for more reliable communication is felt. In this research, a new approach to the linear error correcting codes is introduced. Among advantages of this technique are simpler code construction and also decoding algorithm as well as easier understanding of the basic concept. Based on an earlier paper and also recent work done, we first discuss briefly the use of Karnaugh map and its advantages in constructing simple codes. We then prove a theorem on application of the map to multiple error correcting codes. Using these results, we propose a simple technique that leads to obtaining a code with more capabilities. We also discuss another advantage of using the Karnaugh map in error correcting codes. As an example, we discuss a special case of generating a double error correcting code and, using Karnaugh map features to give it extended capabilities. Keywords. Karnaugh map, Linear codes, Hamming distance, Hamming type code, Code word, S-map, K-code.

In recent years, distributed electrical power generation systems have attracted more attention due to their small scale technologies, lower cost electricity generation and higher reliability and security with fewer environmental consequences rather than traditional power generators. Various applications such as peak saving, co generation, remote power and premium power will make its use more and more. On the other hand, the permanent magnet synchronous generators driven by micro turbines play an important role in the distributed power generation systems. These PM generators produce a high frequency electrical power which needs to be converted to the usual power frequency, 50 Hz or 60 Hz. This conversion is usually done using a back to back combination of rectifier, DC-link and inverter. The main focus of this paper is to present a model for a voltage source rectifier which is connected to a PM generator in a micro turbine unit, where Virtual Flux based Direct Power Control strategy is used to control the mentioned rectifier. The simulation results, using Matlab/Simulink, are presented to show the validity of the proposed model for the PWM rectifier and to evaluate the performance of the control strategy.

Keywords:
PWM rectifier, Virtual Flux based Direct Power Control (VF-DPC), Micro Turbine Unit (MTU), Permanent Magnet Synchronous Machine (PMSM)

ANSI RBAC is a standard for a consistent and uniform definition on Role Based Access Control features and their functional specifications [1]. We analyze both static and dynamic separation of duty constraints specifications in ANSI RBAC standard and evaluate their reliabilities. We then suggest the necessary improvements that make them completely reliable.

Keywords:
Role Based Access Control, Separation of Duty, constraints, ANSI RBAC, Standard, Security, Reliability

This study compares the dynamic behaviors of the Lorenz system with complex variables to that of the standard Lorenz system involving real variables. Different methodologies including the Lyapunov Exponents spectrum, the bifurcation diagram, the first return map to the Poincaré section, and the topological entropy were used to investigate and compare the behaviors of these two systems. The results show that expressing the Lorenz system in terms of complex variables leads to more distinguished behaviors that could not be achieved in the Lorenz system with real variables such as quasi-periodic and hyper-chaotic behaviors.

Keywords:
Lorenz system, Complex variables, Chaos, Hyper-chaos.

The biopotential is an electrochemical potential that has been shown to correlate well with coagulation zone size during cardiac RF catheter ablation. We designed an in vivo experiment to test the hypothesis that a similar correlation exists during hepatic RF ablation. We created coagulation zones in vivo in porcine liver with 17 gauge needle electrodes using RF ablation (n=56). Power was set constant at 30 W, controlled by impedance, and applied for 60, 120 or 180 s. We measured the biopotential between electrode and ground pad with low-pass filtering. Diameter and volume of the coagulation zone were measured and correlated with change in biopotential between beginning and end of each ablation procedure. Moderate correlation between biopotential change and both coagulation zone volume (R2=0.43) and diameter (R2=0.31) were observed. The time constant of biopotential change was not significantly different than the time constant of ablation zone diameter (36.6 s, p=0.93), and biopotential may therefore predict the time course of ablation zone diameter. The biopotential can potentially be used for intraprocedural monitoring of the progression of the thermal damage zone. It may also allow termination of the procedure if the biopotential reliably correlates with the cessation of ablation zone expansion.

Keywords:
Radiofrequency ablation, RF ablation, thermal therapy, cancer, tumor ablation

Abstract Self-Organizing Maps (SOMs) are the most well-known unsupervised neural network approach to clustering.It is very efficient in handling large and high dimensional datasets. The original Particle Swarm Optimization (PSO) is another algorithm discovered through simplified social model simulation. It is effective in nonlinear optimization problems and easy to implement. In the present study we combine these two methods and introduce a new method for anomaly detection. A discussion about our method is presented and its results are compared with some other methods and demonstrate its advantages over them. In order to apply our method, we also performed a case study on forest fire detection. Our algorithm was shown to be simple and functions better than previous ones. We can apply it in different domains of anomaly detection. In fact we observed our method to be a generic algorithm for anomaly detection and may need a few changes to implement it in different domains. Key words: anomaly detection, data fusion, neural network, PSO, forest fire

In this paper, the operational Tau method is employed to approximate the solution of two dimensional linear Volterra integral equations of the first kind ( 2DLVIEF ). To this end, we convert the 2DLVIEF to the equivalent equation of the second kind and then we use operational approach of the Tau method with standard base to convert it to the system of algebraic equations. Finally, some numerical examples are given to clarify efficiency and accuracy of the presented method. keywords : Two-dimensional linear Volterra integral equations, Operational Tau method.

A Highly Computational Efficient Method to Solve Nonlinear Optimal Control Problems Amin Jajarmi 1, , Naser Pariz 2, Ali Vahidian Kamyad 3, Sohrab Effati 4 1,2Advanced Control and Nonlinear Laboratory, Department of Electrical Engineering, Ferdowsi University of Mashhad, P. O. Box 91775-1111, Mashhad, Iran. 3,4Department of Applied Mathematics, Faculty of Mathematical Sciences, Ferdowsi University of Mashhad, P. O. Box 1159-91775, Mashhad, Iran. Abstract: In this paper, a new analytical technique, called the optimal homotopy perturbation method (OHPM), is suggested to solve a class of nonlinear optimal control problems (OCP’s). Applying the OHPM to a nonlinear OCP, the nonlinear two-point boundary value problem (TPBVP), derived from the Pontryagin’s maximum principle, is transformed into a sequence of linear time-invariant TPBVP’s. Solving the latter problems in a recursive manner provides the optimal trajectory and the optimal control law, in the form of rapid convergent series. Furthermore, the convergence of obtained series is controlled through a number of auxiliary functions involving a number of constants, which are optimally determined. In this study, an efficient algorithm is also presented, which has low computational complexity and fast convergence rate. Just a few iterations are required to find a suboptimal trajectory-control pair for the nonlinear OCP. The results not only demonstrate the efficiency, simplicity, and high accuracy of the suggested approach, but also indicate its effectiveness in practical use. Keywords. Nonlinear optimal control problem

Pontryagin’s maximum principle
two-point boundary value problem
optimal homotopy perturbation method
suboptimal control.

Heuristic Mathematical Formulations and Comprehensive Algorithm for Optimal Decision Making for Power System Cabling Running title: Algorithm for Optimal Decision Making for Power Cabling Vahid Abbasi, Hossein Heydari and Framarz Faghihi Center of Excellence for Power System Automation and Operation Electrical Engineering Department Iran University of Science and Technology, Tehran, Iran Corresponding author, P.O. Box 16846-13114, Iran, e-mail: heydari@iust.ac.ir Abstract:
This paper proposes novel method for optimal cabling route

a combinatorial design Algorithm through heuristic mathematical formulations, to choose optimal path when two or more physical paths are available. The best path from EMC point of view can be chosen based upon various criteria such as monetary cost minimization, voltage drop and quality (EMC) parameters. This paper initially provides a numerical 2D and 3D resolution of the problems of radiation generated by current sources. The proposed approach is based on the finite element method associated with absorbing boundary conditions. The presented model makes it possible to consider wave propagation and their effects in heterogeneous mediums in transient which can be applied in EMC for the simulation of radiation. Initially, the formulations for electromagnetic modeling of the proposed problem are specified in details. The simulation results are used for the cabling routes with respect to undesirable field distribution in the specified regions. Based upon the aforementioned criteria, by using Analytical Hierarchy Process the intelligent choice of optimal cabling routes can be achieved. Hence comes the need for the proposed method to be successfully implemented on two different types of power systems, "current injection system and high voltage substation".

Keywords:
analytical hierarchy process (AHP), current injection transformer, electromagnetic compatibility (EMC), heuristic method, interference field, substation