883 research outputs found
Some Paranormed Difference Sequence Spaces of Order Derived by Generalized Means and Compact Operators
We have introduced a new sequence space
combining by using generalized means and difference operator of order . We
have shown that the space is complete under some
suitable paranorm and it has Schauder basis. Furthermore, the -,
-, - duals of this space is computed and also obtained necessary
and sufficient conditions for some matrix transformations from to . Finally, we obtained some identities or
estimates for the operator norms and the Hausdorff measure of noncompactness of
some matrix operators on the BK space by
applying the Hausdorff measure of noncompactness.Comment: Please withdraw this paper as there are some logical gap in some
results. 20 pages. arXiv admin note: substantial text overlap with
arXiv:1307.5883, arXiv:1307.5817, arXiv:1307.588
Shape Memory Alloy Actuators and Sensors for Applications in Minimally Invasive Interventions
Reduced access size in minimally invasive surgery and therapy (MIST) poses several restriction on the design of the dexterous robotic instruments. The instruments should be developed that are slender enough to pass through the small sized incisions and able to effectively operate in a compact workspace. Most existing robotic instruments are operated by big actuators, located outside the patient’s body, that transfer forces to the end effector via cables or magnetically controlled actuation mechanism. These instruments are certainly far from optimal in terms of their cost and the space they require in operating room. The lack of adequate sensing technologies make it very challenging to measure bending of the flexible instruments, and to measure tool-tissue contact forces of the both flexible and rigid instruments during MIST. Therefore, it requires the development of the cost effective miniature actuators and strain/force sensors. Having several unique features such as bio-compatibility, low cost, light weight, large actuation forces and electrical resistivity variations, the shape memory alloys (SMAs) show promising applications both as the actuators and strain sensors in MIST. However, highly nonlinear hysteretic behavior of the SMAs hinders their use as actuators. To overcome this problem, an adaptive artificial neural network (ANN) based Preisach model and a model predictive controller have been developed in this thesis to precisely control the output of the SMA actuators. A novel ultra thin strain sensor is also designed using a superelastic SMA wire, which can be used to measure strain and forces for many surgical and intervention instruments. A da Vinci surgical instrument is sensorized with these sensors in order to validate their force sensing capability
Performance Evaluation of QUIC protocol under Network Congestion
TCP is a widely used protocol for web traffic. However, TCP€™s connection setup and congestion response can impact web page load times, leading to higher page load times for users. In order to address this issue, Google came out with QUIC (Quick UDP Internet Connections), a UDP-based protocol that runs in the application layer. While already deployed, QUIC is not well-studied, particularly QUIC€™s congestion response as compared to TCP€™s congestion response which is critical for stability of the Internet and flow fairness. To study QUIC€™s congestion response we conduct three sets of experiments on a wired testbed. One set of our experiments focused on QUIC and TCP throughput under added delay, another set compared QUIC and TCP throughput under added packet loss, and the third set had QUIC and TCP flows share a bottleneck link to study the fairness between TCP and QUIC flows. Our results show that with random packet loss QUIC delivers higher throughput compared to TCP. However, when sharing the same link, QUIC can be unfair to TCP. With an increase in the number of competing TCP flows, a QUIC flow takes a greater share of the available link capacity compared to TCP flows
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