the method of sampling unit was applied according to the importance of the park in urban landscape structure with the initial purpose of planning method to maximize environmental sustainability and recognizing the structural elements within the park. swot technique has been applied to analyze collected data and evaluate the strengths and weaknesses, opportunities and threats of affected areas. ...

the intervention of urban design in irans architectural structures has been for many years a challenging issue for architects and urban designers over their professional realm. the preservation of architectural structures in iran has always resorted to extremes. this control and direction has sometimes resulted in exclusion of architecture position and has sometimes, once faced with lack of pro...

background  & aim: case-crossover  studies are the case-control  version of crossover studies. in these studies, cases and controls are the same subjects. the term crossover is applied for designs that all subjects pass through both treatment (exposure) and placebo (non-exposure) phases. in fact they are  crossover  of  subjects  between  periods  of  exposure  and  non-exposure.  this  design ...

due to the changes which may occur in their parameters, systems are usually demonstrated by some subsystems for different conditions. this paper employs modified petri nets (mpn) to model theses subsystems and makes it simple to analyze them. in this method, first, the continuous transfer function is converted to a discrete transfer function and then, by mpn, system is modeled and analyzed. all...

Digital Clay is a proposed novel three-dimensional computer input and output device for surface shape and haptic effects. The device consists of an array of fluidic actuators under the control of valves connected to two pressure reservoirs in a manner ultimately suitable to an implementation in MEMS technology. The challenges to build this device lie in both the kinematical structure design and...

Active control of the production choke valve is the recommended solution to prevent casing-heading instability in gas-lifted oil wells. Focus of this work is to find a simple yet robust control structure for stabilization of the system. In order to find suitable control variables, a controllability analysis of the system with different candidate control variables and two alternative manipulated...

Reactive Distillation (RD) is the combination of reaction and distillation in a single vessel (Backhaus, 1921). Over the past two decades, it has emerged as a promising alternative to conventional “reaction followed by separation” processes (Towler & Frey, 2002). The technology is attractive when the reactant-product component relative volatilities allow recycle of reactants into the reactive z...

Control structure design (CSD) deals with the following fundamental question: Given the process flowsheet, where should the controllers be placed, or more specifically, what variables should be measured (sensors) and manipulated (valves) and how should the two sets be interconnected for safe and economic operation? These choices are not obvious for most systems encountered in practice. The prob...

Abstract. This work presents the development of a flight control law design structure, based on the H∞ and μ synthesis theory. The design criteria includes usual robustness and performance requirements related to parameters uncertainty in the vicinity of the design point. In addition, the conventional mixed sensitivity design scheme is changed to comply with specific requirements of a flight co...