Article history: Received 18 January 2011 Received in revised form 14 March 2012 Accepted 3 August 2012 Available online xxxx

abstract: this paper presents dynamic modelling and control of a linear prismatic series of elastic actuator. the capability of generating large torques is why this actuator is increasingly used in human-assistive robotic systems. due to having human in the loop, the actuator requires precise control. a fractional pid controller known for its improved performance is used for the control, due to...

this paper deals with volume fraction optimization of functionally graded (fg) beams resting on elastic foundation for maximizing the first natural frequency. the two-constituent functionally graded beam consists of ceramic and metal. these constituents are graded through the thickness of beam according to a generalized power-law distribution. one of the advantages of using generalized power- l...

an optimal desirability function method is proposed to optimize multiple responses in multiple production scenarios, simultaneously. in dynamic environments, changes in production requirements in each condition create different production scenarios. therefore, in multiple production scenarios like producing in several production lines with different technologies in a factory, various fitted res...

Although there is no more iconic, stalwart, and eloquent defender of liberty and representative democracy than J. S. Mill, he sometimes endorses nondemocratic forms of governance. This article explains the reasons behind this seeming aberration and shows that Mill actually has complex and nuanced views of the transition from nondemocratic to democratic government, including the comprehensive an...

This paper investigates the problem of selecting and scheduling a set of projects among available projects. Each project consists of several tasks and to perform each one some resource is required. The objective is to maximize total benefit. The paper constructs a mathematical formulation in form of mixed integer linear programming model. Three effective metaheuristics in form of the imperialis...

In this study, a new approach isintroduced to solve Blasius differential equation using of ImperialistCompetitive Algorithm (ICA). This algorithm is inspired by competitionmechanism among Imperialists and colonies and has demonstrated excellent capabilitiessuch as simplicity, accuracy, faster convergence and better global optimumachievement in contrast to other evolutionary algorithms. The obta...