Sharif Digital Repository

It has been known that finding a minimal pseudo state space realization for a fractional order transfer function is helpful in circuitry implementation of such a transfer function with the minimum number of fractional capacitors. Considering this importance, the present paper deals with finding minimal realizations for some classes of fractional order transfer functions. To this end, at first some upper bounds are obtained for the minimal inner dimension of a fractional order transfer function. By considering these upper bounds and also the lower bounds, previously presented in literature, the minimal inner dimension is exactly found for some classes of fractional order transfer functions.... 

Computed Tomography (CT) medical images show a specific part of human body and present it in a digital form. Lossless image compression is one of the medical imaging applications. To implement such application on hardware we need a simple and fast algorithm. Differential pulse code modulation (DPCM) is a simple and efficient method for transforming image. In this paper best predictor for DPCM introduce in a manner in which has the best result in compression and also be efficient for hardware implementation. After transforming image by DPCM, Huffman encoding used to compress image. We introduce this method with application to brain CT images  

In this study, a novel scheme for fiber optic strain sensor has been introduced. This scheme is indeed a Mach-Zehnder interferometer followed by a displacement sensor. The strain is applied to an optical fiber which is the main branch of the Mach-Zehnder interferometer and causes an alteration in the interferometer's output intensity. The output beam is then spread on a mirror located in front of the fiber head. The head of the fiber and the mirror form a displacement sensor configuration. The portion of the reflected beam, gathered by the fiber, is a function of the distance between the fiber head and the mirror. So, applying strain causes a new change in the gathered intensity due to the... 

This paper presents a novel approach for evaluating the reliability of protective systems taking into account its components reliability. In this paper, a previously proposed extended model is used for Directional Overcurrent scheme. In the extended model, the impacts of individual protective components are taken into account. An optimum routine test schedule is determined for each protective component as a separate unit. A comparison is made to show that the proposed approach has excellence over conventional routine test inspections. Impacts of factors such as circuit breaker inadvertent opening, required time for performing routine test inspections, human mistakes and self-checking and... 

In this paper, conditions for checking the realizability of fractional-order impedance functions by passive networks composed of a fractional element (either a fractional capacitor or a fractional inductor) and some RLC components are derived. To this end, at first the newly obtained conditions for realizability of fractional-order impedance functions by a passive network composed of a fractional capacitor and some RLC components are extended to include the case that the polynomials involving in the impedance function can have roots on the imaginary axis. Then, the necessary and sufficient conditions are found on a fractional-order impedance function to be realized by a passive network... 

Power generation consumes a substantial amount of water in the power industry. In order to address the impact of water consumption restriction on the power generation, this paper proposes a security-constrained unit commitment (SCUC) formulation considering water consumption impact as an additional constraint. To this end, the water consumption in power plants is formulated. Consequently, the SCUC is extended to consider the consumed water volume as a restricting factor. A procedure is introduced to investigate the most appropriate point of power generation operation to save a vital amount of water by raising reasonable generation costs. The objective of the proposed model is to minimize the... 

In this letter, we propose a novel communication scheme for macro-scale molecular timing channels (MTCs), where the information carrier is the release time of the molecules. Next, the symbol constellation, receiver's sampling time, and receiver's decision rule are designed and analyzed. We further propose a computationally simple yet optimal receiver. Our numerical results show that macro-scale MTC is an approach for achieving ultra-reliable molecular communication. © 2012 IEEE  

Employing Multi-Turn Wound-Rotor (WR) resolvers are suggested for applications that high accuracy and absolute measurement are required, simultaneously. Conventional multi-turn resolvers are consisted of two individual resolvers in a common frame and suffer from high cost and big size that has a loading effect on the driven machine. Those challenges are over-come in proposed structures of recent researches in the price of a complicated winding process in manufacturing where the aim of this paper is laying. To find the best solution, an index is proposed and calculated. All the simulations are done using time-stepping finite element analysis (TSFEA). Then, the prototype of the optimal... 

The principle, configuration, and the special features of a stable platform digital controller are presented in this paper. The main goal of this paper is replacing an analog controller with its awaiting digital one. This has been done using TMS320LF2402 digital signal processor which offers the enhanced TMS320 DSP architectural design of the C2xx core CPU for low-cost, low-power, and high-performance processing capabilities. The experimental results show that the digital controller is identical to the analog one and can be a suitable replacement for the analog controller. Copyright © 2008 by Department of Electronics, AGH University of Science and Technology  

This paper addresses scheduling problem of independent tasks in the market-based grid environment. In market-based grids, resource providers can charge users based on the amount of resource requested by them. In this case, scheduling algorithms should consider users' willingness to execute their applications in most economical manner. As a solution to this problem, a hybrid genetic algorithm and variable neighborhood search is presented to reduce overall cost of task executions without noticeable increment in system makespan. Simulation results show that our algorithm performs much better than other algorithms in terms of cost of task executions. Considering the negative correlation between... 

Simulation is the gold standard for training in aviation and trauma medicine. Now it is available for diseases diagnosis and treatment. With simulation, clinicians can practice their art in a realistic, consequence free environment, combining both theory and practice in a comprehensive program. Method and materials - In the virtual clinical environment of "VPsoft mentor" software, the practitioner reviews a patient's history, orders laboratory tests and procedures, interprets findings, renders diagnoses, and prescribes medication. Every diagnostic or treatment decision the clinician makes for the patient is analyzed by E-mentor, providing instant feedback.Results - This software have been... 

In this paper, Plate Frame Interaction (PFI) developed by other researches for modeling Steel Plate Shear Wall (SPSW) is applied for designing a half-scale, single bay and one story SPSW. After designing of SPSW, one specimen is constructed accordingly. In order to determine the mechanical properties of steel, coupon test is performed; and then again theoretical relations based on PFI is re-checked. In this study, gravity loads are neglected and only seismic resistance of SPSW is considered. With cyclic lateral loading as quasi-static load, according to Acceptance Criteria for Cyclic Racking Shear Tests For Metal-Sheathed Shear Walls with Steel Framing (AC154) and obtaining its hysteretic... 

Health, Margin and Risk states which in recent years are known as well-being reliability indices, provide a comprehensive adequacy assessment of bulk power system reliability studies. Conventional reliability information about power system operation only considered health and risk states which were not often adequate criteria both in system planning and utilization. It seems margin state as the intermediate condition between health and risk must be considered. Well-being method which is a approach to power system generation adequacy evaluation incorporates deterministic criteria in a probabilistic framework and provides system operating information in addition to risk assessment and can be... 

The development and the implementation of a new guidance law are addressed for a six dimensional trajectory tracking problem, three dimensions for position tracking and three dimensions for velocity tracking, of a micro air vehicle. To generate the desired trajectory a virtual leader is defined which is moved in space. In the guidance law, position and velocity feedbacks are used by fuzzy controllers to generate two acceleration commands. Then, a fuzzy coordinator is applied to coordinate the acceleration commands. Nonlinear six-degree-of-freedom equations of motion are used to model the vehicle dynamics. Also, a bank-to-turn acceleration autopilot for vehicle is considered to follow the... 

This paper describes a neural network controller for autonomous underwater vehicles (AUVs). The designed online multilayer perceptron neural network (OMLPNN) calculates forces and moments in earth fixed frame to eliminate the tracking errors of AUVs whose dynamics are highly nonlinear and time varying. Another OMLPNN has been designed to generate an inverse model of AUV, which determine the appropriate propeller's speed and control surfaces' angles receiving the forces and moments in the body fixed frame. The designed approximation based neural network controller with the use of the backpropagation learning algorithm has advantages and robustness to control the highly nonlinear dynamics of... 

This paper is dealing with single phase PWM rectifier parameter optimization. A control loop has been designed to attain a suitable output DC voltage with minimum ripple, input current with minimum harmonic and maximum input power factor. In this paper these parameters have been optimized by using Genetic algorithm. To verify the effectiveness of proposed optimization, different simulations have been done. The simulation results prove that the proposed system working good  

There has been a rising trend towards robotic tele-surgery operations in recent years. A major concern, however, is the lack of direct contact between the surgeon and patient's body. Several researchers have proposed various designs of tactile sensors for surgical instruments to improve the dexterity of surgeons. Previously designed sensors, however, are mostly suitable for instruments with small contact areas. In this paper, a novel tactile sensor is introduced in integration with the teeth of a surgical grasper for large organs. It includes strain gauges embedded underneath a toothed plate, which also act as grasping teeth of the jaws of the instrument. The thickness of the plate and the...