Sharif Digital Repository

This paper presents a mathematical model describing how the physicians actually make a diagnostic decision. Next to a description of diagnostic decision making as done by the physicians, this paper shows that how can we design and develop a new approach to medical diagnosis based on the human principles of decision making. The model was challenged to diagnose a series of actual patients. Real clinical data was entered into the model and the system produced a ranked list of possible diagnoses for each case. The results indicated good performance when compared with internist's diagnosis. The proposed method is effective and can be applied to describe medical reasoning as done by the... 

In this paper two novel search methods for solving optimal power flow (OPF) have been presented and compared. Electricity is undergoing a restructuring process, moving from integrated environment towards deregulation and reduced regulation all around the world. Electrical energy markets are going to be created as a consequence of this process. In order to meet technical issues, system operator would need to apply some ancillary services. Reactive power is one of the most important ancillary services, which should be injected to power network in order to decrease the total loss and control the voltage profile. The main goal of this study is to present a method based on a Locational Marginal... 

Non-linear bending analysis of tapered functionally graded (FG) beam subjected to thermal and mechanical load with general boundary condition is studied. The governing equations are derived and a discussion is made about the possibility of obtaining analytical solution. In the case of no axial force along the beam, a closed form solution is presented for the problem. For the general case with axial force, the Galerkin technique is employed to overcome the shortcoming of the analytical solution. Moreover, the Generalized Differential Quadrature (GDQ) method is also implemented to discretize and solve the governing equations in the general form and validate the results obtained from two other... 

Arbuscular mycorrhizal (AM) fungi are non-specific symbionts developing mutual and beneficial symbiosis with most terrestrial plants. Because of the obligatory nature of the symbiosis, the presence of the host plant during the onset and proceeding of symbiosis is necessary. However, AM fungal spores are able to germinate in the absence of the host plant. The fungi detect the presence of the host plant through some signal communications. Among the signal molecules, which can affect mycorrhizal symbiosis are plant hormones, which may positively or adversely affect the symbiosis. In this review article, some of the most recent findings regarding the signaling effects of plant hormones, on... 

In this paper, a biosignal analysis approach to determine the relation between a typical cell action current (potential) and its resulted biosignals is presented. This relation is a logical result that can be obtained from the electrophysiological concepts governing the biosignals generating phenomena and can tell us some facts about its generating organ. Therefore, one has an input (Action Current or AC), an output (biosignal) and an unknown system (black box) relating them together. In this study, a linear system modeling is proposed to identify that relationship. This system acts as a transfer function (or generating function) that generates different forms of biosignal from a unique... 

Due to the deregulation and restructuring in many countries, it is expected that amount of small-scale generations connected to the distribution networks increase. So it is necessary that impact of these kinds ofgenerators on VoltNar control would be investigated. This paper presents a new approach for VoltNar control in distribution system with Distributed Generation (DG) and it has shown that DG can improve the entire performance of network, by means of better controlling of the system and decreasing losses in network. In this approach Genetic Algorithm (GA) has been used as the optimization method where the amount of Dispersed Generation and its controlling parameters, Voltage regulators... 

Due to deregulation and restructuring in many countries, it is expected that the amount of small-scale generations connected to the distribution networks will increase. So, it is necessary that the impact of these kinds of generators on Volt/Var control should be investigated. This paper presents a new approach to Volt/Var control in distribution systems with Distributed Generation (DG). It has been shown that DG can improve the entire performance of a network system, by means of better control and decreasing losses. In this approach, the Genetic Algorithm (GA) has been used as the optimization method, where the amount of DG and its controlling parameters, the voltage regulators situation,... 

Technology enhancement of Distributed Generations, as well as deregulation and privatization in power system industry, shows a new perspective for power systems and subsystems. When a substantial portion of generation is in the form of dispersed and small units, a new connection pattern emerges whereby the dispersed units are embedded in reticulation infrastructure. Now, the flow of power is no longer the same as in the conventional systems, since the dispersed generating plants contribute with generation also at the distribution grids level. Connection of generation to distribution grids cannot effectively be made, unless the some especial control and monitoring tools are available and... 

A continuous growth in nonlinear loads may cause an increment in harmonic distortion and some other important problems in power systems so considering power quality effects in optimal reactive power planning has become more crucial than before. In this paper, optimal reactive power planning based on voltage profile deviation and voltage THD decrement is studied. The planning problem is studied using reactive power injection in each bus bar and genetic algorithm is also used for solving optimization problem. Obtained results for 5-bus and 30-bus IEEE standard networks are also presented. ©2004IEEE  

This paper presents a short term multi-objective planning model for Distributed Generators (DGs) deployment in an electrical network. "Total Cost" and "Emission Cost" are two objective functions which have been going to be minimized in this model by finding the optimal schemes of sizing, placement and DG technologies over a short planning period (static planning). The proposed model can be used for a long term planning period (dynamic planning) in order to consider the timing concept. An interactive fuzzy satisfying method based on Chaotic Local Search and Modified Honey Bee Mating Optimization (CLS-MHBMO) is used to choose the final solution. The effectiveness of the proposed model and... 

An efficient heterogeneous palladium catalyst system has been developed based on immobilization of Pd nanoparticles on silica-bonded N-propylpiperazine sodium N-propionate (SBPPSP) substrate. SBPPSP substrate can stabilize the Pd nanoparticles effectively so that it can improve their stability against aggregation. In addition, grafted piperazine species on to the silica backbone prevent the removing of Pd nanoparticles from the substrate surface. Transmission electron microscopy (TEM) of catalyst is shown the size of Pd nanoparticles, also it confirmed by particle size analyzer which shown the average size of 21 nm for Pd. The catalytic activity of these catalysts was investigated in the... 

Recently, in many countries, power systems are moving towards creating a competitive structure for trading electrical energy. These changes, along with the numerous advantages of the Distributed Generators (DGs), have created more incentives for distribution companies to use these kinds of generators more than ever before. The Volt/Var control is one of the most important control schemes in distribution networks, which can be affected by DGs. This paper presents a new approach for the Volt/ Var control in distribution networks. The output reactive powers of the DGs, Static Var Compensators (SVCs), Load Tap Changers (LTCs) and the settings of the local controllers are chosen as the control... 

This paper presents a novel opposition-based self-adaptive modified gravitational search algorithm (OSAMGSA) for optimal reactive power dispatch and voltage control in power-system operation. The problem is formulated as a mixed integer, nonlinear optimization problem, which has both continuous and discrete control variables. In order to achieve the optimal value of loss, voltage deviation, and voltage stability index, it is necessary to find the optimal value of control variables such as the tap positions of tap changing transformers, generator voltages, and compensation capacitor. Therefore, this complicated problem needs to be solved by an accurate optimization algorithm. This paper... 

Electric spring (ES) as a breakthrough in power electronics has led to a revolution in demand-side management. This paper presents flexible power management (FPM) of a networked microgrid (MG) in the presence of renewable energy sources (RESs) and flexibility sources (FSs). The FSs include the novel topology of the integrated unit of ES with electric vehicles (EVs) parking (IUEE) and incentive-based demand response program (DRP). The proposed FPM model is formulated as an optimization problem that minimizes the difference between the expected energy cost and the expected profit of FSs' flexibility subject to the AC optimal power flow (AC-OPF), RESs, FSs, and MG flexibility constraints. In... 

This paper presents a new approach for optimal operation of distribution networks with regard to Distributed Generators (DGs). The objective function in this problem includes cost of active and reactive electrical energy generated by DGs, electrical energy markets and capacitors. Also, this paper presents both application and comparison of the metaheuristic techniques such as the Genetic Algorithm (GA), differential evolution, Ant Colony Optimization (ACO), Particle Swarm Optimization (PSO), tabu search, to optimal operation of distribution networks. These methods are tested on two examples distribution network containing an IEEE 34 distribution test feeders and a practical distribution... 

Some new 1,4-distyrylbenzene derivatives were synthesized by using immobilized palladium nanoparticles on silica-bonded N-propyl morpholine (PNP-SBNPM) as a heterogeneous catalyst. These one-pot reactions afforded a range of stereoselective, symmetrical (E)-1,4-distyrylbenzene derivatives with high yields (78-90%). The green catalyst system is recyclable and allows facile product isolation. The recycled catalyst could be reused six times without appreciable loss of catalytic activity  

An efficient heterogeneous palladium catalyst system has been developed based on immobilization of Pd nanoparticles on silica-bonded N-propylpiperazine (SBNPP) substrate. SBNPP substrate can stabilize the Pd nanoparticles effectively so that it can improve their stability against aggregation. Also, grafted piperazine species onto the silica backbone prevents the removing of Pd nanoparticles from the substrate surface. It seems that the high recyclable capability of Pd-SBNPP catalysts is resulted from these two characteristics. Transmission electron microscopy (TEM) of catalyst is shown the size of Pd nanoparticles in Pd-SBNPP average of 20 nm. Furthermore, X-ray photoelectron spectroscopy...