Journal of Mechanical Science and Technology - This paper presents the design and modeling of the UNI-Copter, a portable spherical unmanned aerial vehicle (UAV) that is powered by a single rotor.... 相似文献
This paper presents the design and performance evaluation of a stable pairwise time synchronization protocol (abbreviated SPS) for capillary machine-to-machine (M2M) networks that provides underlying platform independence and operational stability, even under harsh conditions. SPS achieves the first criterion using a novel technique whereby the M2M device captures incoming or outgoing moments of timing messages. The second criterion is achieved by adaptively adjusting the resynchronization interval. Extensive simulations are conducted to demonstrate the validity and effectiveness of SPS. 相似文献
IntroductionTwenty years ago, a WHO review of the literature assumed that most food-borne disease transmission in developing countries takes place within the home, and advocated a major programme of interdisciplinary research to develop and test cost-effective interventions to promote food hygiene.MethodsThe HACCP approach was applied step by step, to two selected weaning foods prepared by 15 volunteer mothers in peri-urban Mali. After setting Critical Control Points (CCP), actions were taken to control, reduce or eliminate microbial growth at these points. 432 food samples were collected and examined for thermotolerant coliforms in a local laboratory to assess the effectiveness of the approach. Lessons learnt were translated into messages delivered in a pilot study.ResultsTraditional cooking was very effective in eliminating faecal contamination; reheating was as effective as cooking when adopted, because there was no significant difference in the temperatures reached in both cases. Behavioural corrective actions were effective in controlling faecal contamination at the other CCPs (serving the child after cooking and after reheating).ConclusionIn conclusion, the HACCP experiment improved significantly the bacterial safety of both types of weaning food studied. 相似文献
In this paper, an improved space-vector-based hysteresis current controller (SVBHCC) is proposed. The controller determines a set of space vectors from a region detector and applies a space voltage vector selected according to the main HCC. A set of space vectors including the zero voltage vector to reduce the number of switchings is determined from the information of the current errors, which are wider than those of the main HCC. A simple hardware implementation is proposed and the good experimental results of the SVBHCC for a squirrel cage motor are also shown 相似文献
Water Resources Management - Climate change will modify the spatio-temporal variation of hydrological variables worldwide, potentially leading to more extreme events and hydraulic infrastructure... 相似文献
Mobile peer-to-peer networking (MP2P) is a relatively new paradigm compared to other wireless network technologies. In the last 10–15 years, it has gained tremendous popularity because of its usefulness in applications such as file sharing over the Internet in a decentralized manner. Security of mobile P2P networks represents an open research topic and a main challenge regarding the vulnerability of these networks and their convenience to different security attacks such as black hole, Sybil, etc. In this work, we analyze the black hole attack in wireless P2P networks using the AODV as the routing protocol. In a black hole attack, a malicious node assumes the identity of a legitimate node, by creating forged answers with a higher sequence number, and thus forces the victim node to prioritize it as a relay node. We propose a solution based on a modification of the AODV routing protocol, taking into account the behavior of each node participating in the network. The performances of our proposal are evaluated by simulation.
A compliance control method of redundant manipulators is presented. This method is based on the new stiffness model, which allows to modulate accarate joint stiffness of realizing the end effector stiffness to be varied with task requirements. A control model is developed and implemented by the proposed method in a three degree of freedom planar redundant manipulator. Also its effectiveness is validated. 相似文献
The voice coil motor nanoscanner has the advantages of large working range, easy control, and low cost compared to the conventional lead zirconate titanate driven nanoscanner. However, it has a small damping problem which causes mechanical vibration. The mechanical vibration reduces the accuracy as well as servobandwidth, which deteoriates the atomic force microscopy (AFM) image of the samples. In order to solve the vibration problem, the loop shaping technique [for vertical (z)] and input prefilter [for lateral (xy)] are applied. Experimental results of the proposed techniques are presented for vertical (z) and lateral (xy) scanner. Finally, the AFM images are provided to investigate its effect. 相似文献