Mojtaba Ahmadi

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We present a control strategy for a simpliied model of a one-legged running robot which features compliant elements in series with hip and leg actuators. For this model, proper spring selection and initial conditions result in \passive dynamic" operation close to the desired motion, without any actuation. However, this motion is not stable. Our controller(More)
To study the design, control and energetics of autonomous dynamically stable legged machines we have built a planar one-legged robot, the ARL Monopod. Its top running speed of 4.3 km/h (1.2 m/s) makes it the fastest electrically actuated legged robot to date. We adapted Raibert's control laws for the low power electric actuation necessary for autonomous(More)
This paper presents the expansion and implementation of the controlled passive dynamic running (CPDR) strategy for legged robots, previously presented by the authors. The CPDR exploits the underlying passive dynamic operation of the robot's mechanical systems to reduce the energy spent for locomotion. Meanwhile, it ensures the stability of the vertical and(More)
Background: Buprenorphine dependence is a new issue and to our knowledge no scientific papers have been published on treatment of buprenorphine dependency. The goal of this research was to characterize intravenous buprenorphine-dependent individuals with respect to socio-demographic and other background features, and to investigate the effect of methadone(More)
BACKGROUND Relapse of tuberculosis (TB) may develop as the result of reactivation of the endogenous primary infection, or as a result of a exogenous reinfection. This survey evaluated the rate of reactivation versus recent transmission among Iranian and Afghan relapse cases. METHODS The sputum specimens were digested, examined microscopically for(More)
Molecular epidemiology analyses are frequently used in determining epidemiology of tuberculosis. Recently, Mycobacterial Interspersed Repetitive Unit Variable Number Tandem Repeat (MIRU-VNTR) and Spoligotyping has become an important method, as it allows high-through put, discriminatory and reproducible analysis of clinical isolate. The purpose of this(More)