In this paper, a TDMA-based Randomly Addressed Polling protocol (TRAP) is proposed. TRAP employs a variable-length TDMA-based contention stage with the length based on the number of active stations. Simulation results are presented that reveal the superiority of TRAP against the RAP protocol in cases of medium and high offered loads. Furthermore the implementation of TRAP is much simpler than t...

Various aspects of RPC electrode material, such as surface smoothness, surface UV sensitivity and its resistance to HF attack, have been studied. Based on these studies we can direct our R&D effort to some of the most critical issues related to RPC performance and aging. & 2008 Elsevier B.V. All rights reserved.

Jumping is used in nature by many small animals to locomote in cluttered environments or in rough terrain. It offers small systems the benefit of overcoming relatively large obstacles at a low energetic cost. In order to be able to perform repetitive jumps in a given direction, it is important to be able to upright after landing, steer and jump again. In this article, we review and evaluate the...

not in close touch with surgical practice. The standard of excellence is so high that it is difficult to select any section for special mention ; perhaps that on the abdomen is the best; the author is a strong advocate of the rule "when in doubt operate;" with this we think the vast majority of surgeons ngree. As regards appendicitis, the practice is "every case of acute appendicitis, ought to ...

In this paper, an extension of the so-called Intrinsic Passive Control (IPC) is illustrated, showing that an improvement of performances can be achieved by considering different types of energy-storing elements, i.e. “springs”, in the IPC. In particular, two new “springs” are introduced: a ‘variable rest length’ spring and a ‘variable stiffness’ spring, that are properly defined in order to mai...

keywords: rtlinux, comedi, sliding mode control, MRAC control

Background In 2005, Latvia lifted the ban on blood donation for men who have sex with men (MSM). The prevalence of HIV infection in blood donations since then has been stable (around 0.02%), though it is higher than the European average (0.009% in 2006). We aim at describing the MSM who report that their last HIV test was done while donating blood (WDB) to approach the role of MSM in the donor ...