Ship hull plate processing surface fairing with constraints based on B-spline

The problem of ship hull plate processing surface fairing with constraints based on B-spline is solved in this paper. The algorithm for B-spline curve fairing with constraints is one of the most common methods in plane curve fairing. The algorithm can be applied to global and local curve fairing. It can constrain the perturbation range of the control points and the shape variation of the curve, and get a better fairing result in plane curves. In this paper, a new fairing algorithm with constraints for curves and surfaces in space is presented. Then this method is applied to the experiments of ship hull plate processing surface. Finally numerical results are obtained to show the efficiency of this method.

Utility-optimization dynamic subcarrier allocation algorithm for SC-FDMA systems

Two utility-optimization dynamic subcarrier allocation(DSA) algorithms are designed for single carrier frequency division multiple access system(SC-FDMA).The two proposed algorithms aim to support diverse transmission capacity requirements in wireless networks,which consider both the channel state information(CSI) and the capacity requirements of each user by setting appropriate utility functions.Simulation results show that with considerable lower computational complexity,the first utility-optimization algorithm can meet the system capacity requirements of each user effectively.However,the rate-sum capacity performance is poor.Furthermore,the second proposed utility-optimization algorithm can contribute a better trade-off between system rate-sum capacity requirement and the capacity requirements of each user by introducing the signal to noise ratio(SNR) information to the utility function based on the first utility-optimization algorithm,which can improve the user requirements processing capability as well as achieve a better sum-rate capacity.

High Performance Fairness Algorithm for Resilient Packet Ring

Resilient Packet Ring (RPR) is MAN technology with two counter-rotating rings that multiple stations share the bandwidth. The stations on ring must negotiate the allowed rate that they can transmit fairness eligible traffic based on the total amount of uncommitted bandwidth. RPR draft employs distributed bandwidth control algorithm in order to assure global fairness. In this paper, we suggest a new fairness control algorithm termed Congestion Distributed Fairness Algorithm (CDFA) that exhibits better pe...

Automatic Shape Control of Triangular B-Splines of Arbitrary Topology

Triangular B-splines are powerful and flexible in modeling a broader class of geometric objects defined over arbitrary, non-rectangular domains. Despite their great potential and advantages in theory, practical techniques and computational tools with triangular B-splines are less-developed. This is mainly because users have to handle a large number of irregularly distributed control points over arbitrary triangulation. In this paper, an automatic and efficient method is proposed to generate visually pleasing, high-quality triangular B-splines of arbitrary topology. The experimental results on several real datasets show that triangular B-splines are powerful and effective in both theory and practice.

The Effects of Filtered Channel Quality Feedback on Throughput of Proportional Fair Algorithm

The throughput (total bit per second per hertz) of a modified Proportional Fair Algorithm (PFA) is analyzed and computed. The modified PFA introduces a dynamic threshold to filter the feedbacks of Channel Quality (CQ) based on which the users' priorities are calculated for scheduling. Only those in good CQs (relative to their own average CQ) can be the candidates for scheduling. The results show that the modified PFA with a low CQ threshold can not only reduce some feedback overhead but also maintain the throughput of traditional PFA. Interestingly, for a certain combination of system parameters, the throughput gain over traditional PFA can be achieved by this modified PFA. Two methods of calculating priority, one based on signal to noise ratio, and the other on information rate, are considered. Their performances are generally similar in terms of throughput.

Improved proportional fair dynamic subcarrier allocation with frugality constraint for SC-FDMA system

With the objective of taking full use of channel resource, we proposed two utility based dynamic subcarrier allocation （DSA） algorithms for the single carrier frequency division multiple access （SC-FDMA） system, which are the proportional fair frugality constrained （PF-FC） algorithm and the weighted proportional fair frugality constrained （WPF-FC） algorithm. The two proposed algorithms are designed under the frugality constraint （FC） control consideration so as to avoid service rate waste and improve the spectrum efficiency. Moreover, the queuing buffer model in this paper is established on a finite size structure rather than the traditional infinite queuing manner, which is more consistent with the practical transmission condition. Simulation results indicate that the two proposed algorithms can both achieve significantly better system rate-sum capacity and quality of service （QoS） performance than their primary algorithms, and are more applicable for the heterogeneous traffic.