A common method for controlling a group of parallel converters in decentralized control strategy structure in an island microgrid, the use is the droop-down characteristics of frequency ω-P and voltage E-Q. However, the problem with using this method is that the reactive power is not properly distributed (in proportion to the capacity of the micronutrients) between the micronutrients, which may lead to overload in the converters. Microgrids may also suffer from dynamic stability problems such as power fluctuations, which can be increased by switching between active and reactive power control. To avoid this problem, the X / R ratio of transmission lines is an important parameter that should be carefully considered in the design of micronutrient controllers. By linearizing and simplifying conditions, the control system conversion function model becomes a single input-single output system, which is efficient enough to show the relationship between control parameters such as slope of droop characteristics and derivative sentences, virtual impedance, and voltage controllers. Using this model, stability conditions for different parameters are analyzed. Also, to improve power distribution stability, common droop strategies are modified by adjusting the slope as well as adding nonlinear sentence sections. This approach reduces the coupling between active and reactive power control and reduces the dependence of power distribution on grid parameters such as the X / R ratio. To evaluate the reliability of the proposed model, the simulation results in a sample island microgrid in MATLAB software are presented.

Networks-on-Chip (NoC) is an effective solution to inside on-chip communication problems. In recent years, the advancement of silicon industry and also the production of Carbone Nanotube antennas (CNTs), it is possible to use wireless antennas in the network on chip. This new communication structure is called a Wireless Network on Chip (WiNoC). Using the wireless antenna in multi-core chips led to the reduction in the latency and power consumption. In spite of higher bandwidth of the WiNoCs compared to wire NoCs; their performance can decrease significantly in absence of an effective flow control mechanism. In this paper, the flow control problem is investigated by using a mathematical model in the WiNoC. The aim of this study is showing a correct analysis of cores behaviors with the subject to capacity constraints of links and flow rates. The simulation results of traffic pattern in the WiNoC show that the proposed flow rate control algorithm has been able to control and adjust the flow injection rate of each transmitter with acceptable convergence

Background and Aim: In patients with complete denture, some clinicians have used modelling plastic impression compound (MPIC) along tissue conditioner (TC) materials simultaneously. Little information is available on the composition of these materials and the interaction between them. The purpose of this study was to evaluate the influence of two components of MPIC on the structure and chemical composition of TC.Materials and Methods: In this experimental study, MPIC specimens were provided in 25×2 mm discs. Specimens were randomly divided into three groups and were immersed in ethanol 70%, plasticizer (dibutyl phthalate) and a mixture of them (ethanol 70% and dibutyl phthalate). All of the discs were weighed with a digital balance before and 2, 4, 6 and 24 hours after immersion. Values were analyzed by non parametric Kruskal-Wallis (a= 0.05) and SPSS 16 for Windows (SPSS Inc., Chicago, IL) was used for statistical analysis.Results: Statistical analysis indicated significant differences among all groups (p>.05).Conclusion: Dibutyl phthalate (DBP) had high impact on the solubility of MP, while the mixture of dibutyl phthalate (DBP) and ethanol demonstrated the highest impact.

The traditional methods used so far for modeling, analysis, and control of systems are generally based on determining the differential equations governing the system and the designing based on some mathematical methods and algorithms. Recent investigations and studies show that, with the use of some approximations, the most complicated systems can easily be analyzed and controlled without actually being involved in a sophisticated computation or on exact mathematical model. In systems made by man, the efforts in implementing methods similar to Ruman reasoning is the basis of introducing the expert control systems and the artificial intelligence. In this paper, the qualitative control is introduced as one of the recent methods of achieving this objective, the nature of qualitative reasoning, its applications and advantages are discussed and compared with the fuzzy control, which is one of commonly used methods in artificial intelligence.

This paper deals with the modeling and control of a continuous-How fermentation process for the production of alcohol The dynamic behavior of fermentors has been developed from mass balance and leads to nonlinear differential equations. Based on the proposed model, two computer algorithms are provided to control output alcohol concentration at the desired value by input flow rate manipulation. The first algorithm is based on a conventional PID (Proportional-Integral-Derivative), in which its parameters are determined in a trial and error procedure. The second algorithm is based on optimal controllers. In this way, the difference between output alcohol concentration and desired value is minimized by flow rate manipulation. Minimization (optimization) is done based on the MARQUARDT procedure. The advantages of this method over the conventional PID controller are its higher speed and lack of overshoot.

The present paper deals with family and control of youngsters' modeling, one of the contemporary social issues. Youngsters' modeling manifests itself in the form of fashionism, contact with abnormal social groups, tendency towards transient norms and weakness in family relations. Parents' early reactions towards their children go from one extreme to the other. They sometimes become strict and behave outrageously towards the youngsters and sometimes become so permissive that they see neutral about their destiny. The proper way is that the parents manage and organize youngsters' modeling, taking into consideration their age and social conditions using influential educational policies. This paper proposes two macro-policies: "modeling management by maintaining association with the youngsters" and "modeling management through sympathizing with youngsters". These policies are the outcome of a study of Quranic verses and traditions and a review of family background.