Performance of Channel-Aware Scheduling Algorithms for HDR-WPAN

In this paper, we consider the performances in terms of system throughput and response time of various channel-aware scheduling algorithms for both MPEG streams and non-MPEG flows in a high-data-rate (HDR) wireless personal area network (WPAN). The algorithms under investigation are the shortest remaining processing time rule, the exponential rule, the modified largest weighted delay first rule, the maximum rate rule, and the proportionally fair rule. Decodability issues are taken care of by means of the frame-decodability aware technique and the burst transfer eligibility decision mechanism. The impacts of a number of factors including deadline and interference-plus-noise level are also examined. The investigations are carried out through extensive ns-2 simulations. Based on the numerical results, we propose a heuristic scheduling algorithm for MPEG streams that outperforms the above algorithms in terms of system throughput. The findings are useful for system designers.     

Adaptive control of nonlinearly parameterized systems: the smooth feedback case

Studies global adaptive control of nonlinearly parameterized systems with uncontrollable linearization. Using a parameter separation technique and the tool of adding a power integrator, we develop a feedback domination design approach for the explicit construction of a smooth adaptive controller that solves the problem of global state regulation. In contrast to the existing results in the literature, a key feature of our adaptive regulator is its minimum-order property, namely, no matter how big the number of unknown parameters is, the order of the dynamic compensator is identical to one, and is therefore minimal. As a consequence, global state regulation of feedback linearizable systems with nonlinear parameterization is achieved by one-dimensional adaptive controllers, without imposing any extra (e.g., convex/concave) conditions on the unknown parameters.     

The Pay As You Save program in rural Arkansas: An opportunity for rural distribution cooperative profits

This case study highlights the success of the Ouachita Electric Cooperative’s Pay As You Save program in Camden, Ark., in bringing both electricity bill savings to customers and benefits to implementing utilities, especially in rural areas. It is not specifically a low-income energy assistance program, but does benefit customers with high energy burdens. Through its on-bill tariff design, PAYS overcomes many barriers, such as the split incentive challenge and the need for upfront outlays.     

Windows风格的在线帮助系统实现方法

实用的帮助系统是构造现代企业信息管理系统时必须考虑的一个问题。介绍了帮助系统的组成与构造方法,并以开发过的工程为例进一步说明在应用系统中如何嵌入帮助系统。采用这种方法后,使所设计和开发的应用系统更完善、更实用。     

长乐区无花果栽培的气象条件分析

文章利用长乐区1981年—2010年30年气候资料,分析了长乐区无花果生长发育的气象条件,并提出了影响无花果生长的气象灾害应对措施,为无花果在长乐区的推广种植,获得高产稳产提供科学参考。     

A Delay-Dependent Approach to Robust H ∞ Control for Uncertain Stochastic Systems with State and Input Delays

In this paper, the problem of delay-dependent robust H _∞ control for uncertain stochastic systems with state and input delays is investigated. The time delays are assumed to be bounded and time varying and the uncertainties are assumed to be norm bounded. By using the Lyapunov functional method, a new delay-dependent robust H _∞ control scheme is presented in terms of linear matrix inequalities (LMIs). Some numerical examples are given to illustrate the effectiveness of the proposed approach. This work is partially supported by the Natural Science Foundation of China (60674055, 60774047), and the Taishan Scholar Programme of Shandong Province. An erratum to this article can be found at     

Inverse scattering for conductors by the equivalent source method

The inverse scattering for two-dimensional conductors is investigated. Assume that an incident wave is incident upon conducting cylinders of unknown shape and the scattered field is measured outside. By properly processing the scattering data, the position and shape of the conducting scatterers can then be reconstructed. The proposed theory of inverse scattering is a combination of the diffraction tomography and the equivalent source method. To overcome the ill-posedness, the condition of the measured scattered field and the boundary condition on the conductor surfaces are combined and recast into an optimization problem using the least-squares concept. By comparing the reconstructed and the prescribed results, the inversion algorithms are numerically examined. Note that if a priori information of the shape is sufficient and the equivalent sources are properly placed, the algorithms can be flexibly applied to the cases of multiple conductors. Also the effects of noise contamination and multiple scattering on the reconstruction result are numerically investigated     

Simple method for mitigation of polarization crosstalk in silica planar lightwave circuit directional couplers

Polarization crosstalk in planar lightwave circuit directional couplers can cause significant polarization-dependence in interferometers that use them. We show a simple way to mitigate the polarization crosstalk without incurring a performance penalty or requiring extra fabrication steps. We demonstrate it on a 23-ps Mach-Zehnder delay interferometer.