Sharif Digital Repository

Many websites on the Internet offer services to people. They usually ask the users to fill the registration forms for using their services. Unfortunately, some vandalistic persons write programs which make automatic fake registration. For solving this problem, CAPTCHA (Completely Automated Public Turing test to tell Computers and Human Apart) systems are invented. These systems distinguish human users from computer programs. One of the CAPTCHA methods which is designed for Persian and Arabic users is Nastaliq CAPTCHA. In this method, the image of a Persian or Arabic word which is written in Nastaliq font is chosen from a dictionary, and it is shown to the users, then they are asked to type... 

Electromyogram signal (EMG) is an electrical manifestation of contractions of muscles. Surface EMG (sEMG) signal collected form surface of the skin has been used in diverse applications. One of its usages is exploiting it in a pattern recognition system which evaluates and synthesizes hand prosthesis movements. The ability of current prosthesis has been limited in simple opening and closing that decreases the efficacy of these devices in contrary to natural hand. In order to extend the ability and accuracy of prosthesis arm movements and performance, a novel approach for sEMG pattern recognizing system is proposed. In order to have a relevant comparison, present and recent research for... 

In this research, we developed a cost-effective automated guided vehicle for small clothing production workshops that ordinary workers in such workplaces can operate. We acquired workers’ opinions in multiple workshops about using the robots (with some social capabilities) and working alongside them. We performed the tests in China and Iran to investigate and compare different preferences and priorities in two countries with different cultural backgrounds. We used the UTAUT questionnaire and conducted two-way ANOVA tests considering two independent factors: Nationality and Gender. The results showed that workers in Iran and China have relatively similar expectations from a social AGV, with... 

Nowadays automation in distribution systems is growing largely. Automated and remote controlled switches play prominent rules in automated distribution systems. By opening and closing these remote controlled switches in emergency states when a fault has been occurred we can manage fault and restoration process in order to minimize interruption time and costs. In the normal states feeder load management and power loss minimization can be controlled by these remote controlled switches. Finding optimum numbers and optimum locations for installing these switches is the main concern in this between. Up to now a number of algorithms have been developed for optimum switch placement. In this paper a... 

In this paper, we study an adaptive random search method based on continuous action-set learning automaton for solving stochastic optimization problems in which only the noise-corrupted value of function at any chosen point in the parameter space is available. We first introduce a new continuous action-set learning automaton (CALA) and study its convergence properties. Then we give an algorithm for optimizing an unknown function. © 2005 The Franklin Institute. Published by Elsevier Ltd. All rights reserved  

Persian (Farsi) script is totally cursive and each character is written in several different forms depending on its former and later characters in the word. These complexities make automatic handwriting recognition of Persian a very hard problem and there are few contributions trying to work it out. This paper presents a novel practical approach to online recognition of Persian handwriting which is based on representation of inputs and patterns with very simple visual features and comparison of these simple terms. This recognition approach is tested over a set of Persian words and the results have been quite acceptable when the possible words where unknown and they were almost all correct in... 

This paper describes a nursing robot system currently under development at the Center of Excellence in Design, Robotics and Automation. Our goal was to design and fabricate of a robot specifically for paraplegic patients and the design procedure led to a plan which can be employed in any hospital environment. Through the design procedure, the team members conducted a survey on the robot client's needs and disabilities which provided a unique view on mechanical design features, in addition to, performing dynamical analysis on the designed mechanisms. Dynamical Simulation of mechanisms helped us to find the best design and solutions as well as optimization of parts has resulted in a matchless... 

In this study, the kinetics of dynamic recrystallization is predicted under hot rolling conditions employing a first-order rate equation. The proposed model considers the effects of temperature and strain rate variations on recrystallization kinetics by simultaneously modelling heat transfer and plastic deformation phenomena. To do so, a two-dimensional finite element method is coupled with the transformation equation to calculate the temperature distribution and the strain rate field as well as the kinetics of dynamic recrystallization within the metal, concurrently, The model developed was examined for a low carbon steel. A series of hot compression tests were carried out at different... 

Real-time, fuzzy rule-based guidance systems for autonomous vehicles on limited-access highways are investigated. The goal of these systems is to plan trajectories that are safe, while satisfying the driver's requests based on stochastic information about the vehicle's state and the surrounding traffic. This paper presented a new method to implement an automated highway driving behaviour. The main advantage of the suggested system is its well-defined structure. To test the designed system, a simulation tool is implemented. By using the described tool, we can analyse the operation of the implemented decision making system in a simulated highway. Results show an acceptable performance of the... 

Automation is acknowledged by distribution utilities as a successful investment strategy to enhance reliability and operation efficiency. However, practical approaches that can handle the complex decision-making process faced by decision makers to justify the long-term financial effects of distribution automation have remained scarce. An automated and remote-controlled sectionalizing switch play a fundamental role in an automated distribution network. This paper introduces a new optimization approach for distribution automation in terms of automated and remotely controlled sectionalizing switch placement. Mixed-integer linear programming (MILP) is utilized to model the problem. The proposed... 

The application of digital technologies in power systems has resulted in an evolutionary replacement of electromechanical devices with numerical ones featuring internal digital processors with communication capabilities. A substation automation system (SAS) deploys substation operation functions, including control, protection, monitoring, and measuring. Ethernet technology and local area networks (LANs) make it possible to design substation communication architectures with greater reliability, availability, speed, and cost savings than conventional hard-wired systems. This paper proposes a new method to describe topologies of the SAS as an interconnected network. The concept of data... 

Washing the corpse and dressing the body prior to burial is an act of love and necessity in many religions. Applying robotics and automation technologies for the washing and preparation of a deceased Muslim in accordance with the Islamic Shari'at laws has been the challenging foundation of this research. With an increasing annual population growth resulting in an increase in the number of deaths (historically and/or immediately after a national disaster), automating part of this procedure to increase the speed of operation, reducing the health risks to the personnel of washing rooms "Ghassalkhaneh™ at the cemeteries and enhancing their quality of life have been the primary objectives of this... 

Automation is acknowledged by distribution utilities as a successful investment strategy to enhance reliability and operation efficiency. However, practical approaches that can handle the complex decision-making process faced by decision makers to justify the long-term financial effects of distribution automation have remained scarce. An automated and remote-controlled sectionalizing switch play a fundamental role in an automated distribution network. This paper introduces a new optimization approach for distribution automation in terms of automated and remotely controlled sectionalizing switch placement. Mixed-integer linear programming (MILP) is utilized to model the problem. The proposed... 

In the past decade, distribution network operators have been broadly engrossed toward automated distribution networks. The operators acknowledge network automation as an efficient investment toward a better service reliability. This paper aims to provide a new long-term cost/benefit analysis for an optimal level of distribution network automation. In the analysis, reduction in customer outage cost is considered as the benefit of implementing automation systems with capital investment, and annual operation and maintenance costs. In the Finnish regulation model, there is a special incentive based on customer outage cost reduction. As the main contribution of this paper, the impact of earth... 

We concern with both time and cost optimization in an automated manufacturing system. In our proposed system, material handling is carried out by automated guided vehicles and robots for the manufacturing functions. In this way, defect rates, breakdown times, waiting time, processing time, and certain other parameters are not expected to be deterministic. Therefore, we apply stochastic programming to optimize the production time and material handling cost. The proposed stochastic program is a nonlinear model, for this reason we apply a successive linear programming (SLP) technique for its optimization. Numerical test results point to the inefficacy of the proposed optimization method for... 

Operational modal analysis based on power spectral density transmissibility (PSDT) functions is a useful tool to identify the modal parameters with low sensitivity to excitations. For pole extraction from the PSDT function, a proper parametric identification method such as the polyreference least squares complex frequency-domain method or poly-Max method can be used. Then, the poles are selected from a stabilization diagram (SD) with overestimating the system model order. Therefore, spurious modes can be identified that must be distinguished and removed from the system poles. To reach this aim, many techniques have been proposed and applied. In this paper, a new algorithm is proposed to...