6655534
Wing transmission for a micromechanical flying insect
Flapping wings provide unmatched manoeuvrability for flying microrobots. Recent advances in modelling insect aerodynamics show that adequate wing rotation at the end of the stroke is essential for generating adequate flight forces. We developed a thorax structure using four bar frames combined with an extensible fan-fold wing to provide adequate wing stroke and rotation. Flow measurements on a scale model of the beating wing show promising aerodynamics. Calculations using a simple resonant mechanical circuit model show that piezoelectric actuators can generate sufficient power, force and stroke to drive the wings at 150 Hz.
7363256
Towards flapping wing control for a micromechanical flying insect
Considers a 2 DOF resonant thorax structure signed and fabricated for the MFI project. Miniature piezoelectric PZN-PT unimorph actuators were fabricated and used to drive a four-bar transmission mechanism. The current thorax design utilizes two actuated four-bars and a spherical joint to drive a rigid wing. Rotationally compliant flexure joints have been tested with lifetimes over 10/sup 6/ cycles. Wing spars were instrumented with strain gauges for force measurement and closed-loop wing control.
132181
A note on proactive password checking
Nowadays, proactive password checking algorithms are based on the philosophy of the dictionary attack, and they often fail to prevent some weak passwords with low entropy. In this paper, a new approach is proposed to deal with this new class of weak passwords by (roughly) measuring entropy. A simple example is given to exploit effective patterns to prevent low-entropy passwords as the first step of entropy-based proactive password checking.
38959890
The bandwidth sum of join and composition of graphs
Given a graph G, a proper labeling f of G is a one-to-one function f:V(G)->{1,2,...,|V(G)|}. The bandwidth sum of a graph G, denoted by B"s(G), is defined by B"s(G)=min@?"u"v"@?"E"("G")|f(u)-f(v)|, where the minimum is taken for all proper labelings f of G. In this paper, we give some results for the bandwidth sum problem for the join of k graphs G"1,G"2,...,G"k, where each G"i is a path, cycle, complete graph, or union of isolated vertices. We also discuss the bandwidth sum for the composition of two graphs G and H, where G and H are path, cycle, or union of isolated vertices.
9935355
Security design in online games
The emergence of online games has fundamentally changed security requirements for computer games, which previously were largely concerned with copy protection. We examine how new security requirements impact the design of online games by using online bridge, a simple client-server game, as our case study. We argue that security is emerging as an inherent design issue for online games, after graphics and artificial intelligence, which have become important issues of the design of most games for decades. The most important new security concern in online game design is fairness enforcement, and most security mechanisms all contribute to a single objective, namely, making the play fair for each user.
34419420
A Semantic Analyzer for Aiding Emotion Recognition in Chinese
17691685
WFMS-based Data Integration for e-Learning
As more and more organisations and institutions are moving towards the e-learning strategy, more and more disparate data are distributed by different e-learning systems. How to effectively use this vast amount of distributed data becomes a big challenge. This paper addresses this challenge and works out a new mechanism to implement data integration for e-learning. A workflow management system based (WFMS-based) data integration model is contributed to the e-learning