Bottom-Up和Top-Down结合的网络资源规划系统结构研究

为了降低CAPEX和OPEX,运营商需要运营恰到好处的网络规模和Service Ready的服务开通。本文提出了Bottom-Up和Top-Down结合的网络资源规划系统结构,其能够预测未来资源利用率过高或过低及容量不足的网络资源,有利于运营商进行准确的网络资源扩容,从而提升网络建设ROI;能够自动化地实现从业务和市场规划到最终的网络资源规划的转换,从而提高网络资源规划的准确性和效率。     

Cloud-Supported Seamless Internet Access in Intelligent Transportation Systems

Great progress of technologies makes intelligent transportation system (ITS) services increasingly desirable. It becomes essential to seamlessly connecting to the Internet for accessing high quality Internet-enabled ITS services. In this context, gateway is recognized as the logical portal to the Internet. The efficiency of gateway regulation hence significantly sways the quality of ITS services. To seamlessly access the Internet in ITSs, a cloud-supported gateway model is proposed in this paper. Accordingly, the weighty load of gateway government, including gateway registration, discovery, selection, dispatching, and handoff, is offloaded from the clients to the appointed cloud servers. Numerical analyses and simulation results suggest that the gateway model proposed in this paper effectively improves the system performance in terms of the packet delivery rate, end-to-end delay, signaling overhead, and gateway connectivity; and, correspondingly enhances the usage experience of Internet-enabled ITS services.     

Adaptive multistage parallel interference cancellation for CDMA

Although the multistage interference cancellation detector is simple in structure, its performance degrades when the number of active users becomes large. In some cases, the performance is even worse than that without cancellation, due to the lack of the exact knowledge of the interfering signal in cancellation. Partial interference cancellation suggested by Divsalar and Simon (see IEEE Trans. Commun., vol.46, p.258-68, 1998) tries to remedy this weakness by reducing the cost of a wrong interference estimation through a weight in each stage. This paper presents an adaptive multistage structure based on the partial interference cancellation approach. In this structure, the weights are obtained by minimizing the mean-square error between the received signal and its estimate through a least mean square (LMS) algorithm. The resulting weights contain reliability information for the hard decisions made in the previous stage. Neither a training sequence nor a pilot signal is needed in the proposed scheme, and its complexity is much lower than that of linear multiuser detectors. Simulation results show that the proposed scheme can outperform some of the existing interference cancellation methods in both the additive white Gaussian noise (AWGN) and the multipath fading channels     

应用牛顿迭代法进行水库调洪计算

水库调洪计算的基本原理就是水量平衡方程，由于水库水位和水库下泄流量之间具有函数关系，因此求解水量平衡方程必须进行试算，必须预先确定迭代初值和迭代区间，如果迭代初值和迭代区间选取不当，计算收敛速度就很慢甚至发散，难以满足水库管理高度的要求，针对上述问题，本文提出了水库调洪计算的牛顿迭代法，该方法的特点是夫需计算者预先确定失代初值和迭代区间，并具有很高的计算精度和计算效率，本文还对水库调洪计算的牛顿迭     

A composite-resonator mode description of coupled lasers

We investigated the behavior of two lasers operating with coupled resonators. Our analysis involves a decomposition of the laser field in terms of the passive composite resonator eigenmodes. The interaction between the laser field and the active medium is found to lead to mode coupling, The dominant coupling mechanism is cross saturation among composite-resonator modes. The effects of cross saturation on the output of the coupled lasers are investigated. Our results are valid for all values of coupling between lasers. Examples of lockbands calculated using the composite-resonator mode analysis are presented.     

R134a和R22在水源热泵应用中的性能研究和比较

用R134a和R22作为制冷剂在相同的水源热泵系统里进行实验,对比研究了各自的性能及其冷凝出水范围。实验结果表明:在相同的蒸发进水温度和冷凝出水温度下R22有着较高的制热量,高约30%,但是R134a的COP相对较高,高约5%;特别是在高温时R134a的压比以及功耗都在正常的工作范围内。     

Photoluminescence enhancement of quantum dots with different emission wavelengths using oxide shell-isolated Au nanoparticles

Journal of Materials Science - Improving the quantum yield of non-toxic InP/ZnS QDs is essential for its commercial application in illumination and displays. In this work, single size Au...     

A two-phase GA model for resource-constrained project scheduling

In construction scheduling, problems can arise when each activity could start at different time points and the resources needed by the activities are limited. Moreover, activities have required conditions to be met, such as precedence relationships, resource requirements, etc. To resolve these problems, a two-phase GA (genetic algorithm) model is proposed in this paper, in which both the effects of time-cost trade-off and resource scheduling are taken into account. A GA-based time-cost trade-off analysis is adopted to select the execution mode of each activity through the balance of time and cost, followed by utilization of a GA-based resource scheduling method to generate a feasible schedule which may satisfy all the project constraints. Finally, the model is demonstrated using an example project and a real project.