新时期准公益性水管单位经营探索

2011年,中共中央、国务院以一号文件的形式下发了《关于加快水利改革发展的决定》,水利事业改革发展迎来了一个新的春天。在这种新形势、新情况下,准公益性水管单位如何把握水利发展的重大机遇,在国家规定之内搞好经营活动,实现水管单位的综合效益最大化是值得研究的一个课题。本文以探索准公益性水管单位的经营为重点,阐述了国家对准公益性水管单位经营活动的规定,分析了在水利改革发展重大机遇期准公益性水管单位经营面临的形势,对准公益性水管单位如何走经营之路进行探索。     

基于人才成长规律的维修任务分配模型研究

针对我军各维修级别的不同情况,对不同维修级别的装备保障人才影响因素进行了分析研究,建立了不同维修级别装备保障人才成长的模型.并运用实例对模型的正确性进行了说明和验证,实例结果表明,该模型更贴近部队实际,对于部队的维修任务分配有重要的指导作用.     

Fair relay selection in decode-and-forward cooperation based on outage priority

The opportunistic cooperation schemes,where only the "best" relay is selected to forward the message,have been widely investigated recently for their good performance in terms of outage probability.However,the unfair selections of relays may cause unbalance power consumptions among relays,which reduces the lifetime of energy constrained networks.In this paper,we introduce a novel concept of outage priority based fairness(OPF),aiming at improving the selection fairness among relays appropriately without outage performance deterioration.Then,a cooperation scheme is proposed to meet this concept,and corresponding theoretical analysis is also provided.Afterward,based on OPF,the achievable upper bound of the fairness is derived,and an optimal cross-layer designed scheme is also provided to achieve the bound.Numerical simulations are carried out finally,which not only validate the theoretical analysis,but also show that taking advantages of the proposed schemes,the fairness among all relays,as well as the network lifetime,can be greatly improved without any loss of outage performance,especially in high SNR regime.     

Path planning in complex 3D environments using a probabilistic roadmap method

This paper presents a 3D path planning algorithm for an unmanned aerial vehicle （UAV） in complex environments. In this algorithm, the environments are divided into voxels by octree algorithm. In order to satisfy the safety requirement of the UAV, free space is represented by free voxels, which have enough space margin for the UAV to pass through. A bounding box array is created in the whole 3D space to evaluate the free voxel connectivity. The probabilistic roadmap method （PRM） is improved by random sampling in the bounding box array to ensure a more efficient distribution of roadmap nodes in 3D space. According to the connectivity evaluation, the roadmap is used to plan a feasible path by using A＊ algorithm. Experimental results indicate that the proposed algorithm is valid in complex 3D environments.     

A new image fusion performance metric based on visual information fidelity

Because subjective evaluation is not adequate for assessing work in an automatic system, using an objective image fusion performance metric is a common approach to evaluate the quality of different fusion schemes. In this paper, a multi-resolution image fusion metric using visual information fidelity (VIF) is presented to assess fusion performance objectively. This method has four stages: (1) Source and fused images are filtered and divided into blocks. (2) Visual information is evaluated with and without distortion information in each block. (3) The visual information fidelity for fusion (VIFF) of each sub-band is calculated. (4) The overall quality measure is determined by weighting the VIFF of each sub-band. In our experiment, the proposed fusion assessment method is compared with several existing fusion metrics using the subjective test dataset provided by Petrovic. We found that VIFF performs better in terms of both human perception matching and computational complexity.     

Efficient bidirectional quantum secure communication with two-photon entanglement

An efficient bidirectional quantum secure communication protocol is proposed with two-photon entanglement. Compared with the previous protocol proposed by Shi et al., our protocol can achieve higher efficiency. Meanwhile, for the same length secret messages, only half of entangled photon pairs need to be prepared in our protocol. And the number of classical bits in public classical communication is also a half of that in the previous protocol. Moreover, the information leakage does not exist in our scheme.     

Is quantum key distribution suitable for steganography?

Recently a quantum steganographic communication protocol based on quantum key distribution (QKD) was proposed, where it is believed that QKD is a kind of suitable cover of a steganographic communication because QKD itself is not deterministic communication. Here we find that, as a special cryptographic application, the procedure of QKD can be used for deterministic secure communication, and consequently it is not suitable for steganography. Due to similar reasons, other quantum cryptographic schemes, including quantum secret sharing and quantum secure direct communication, are not suitable for steganography either.     

GPU在密码处理领域应用研究

分析了GPU在密码处理领域的应用发展趋势,给出了典型硬件架构设计和软件架构设计,分析了涉及到的关键技术,对GPU在密码处理领域的设计和应用具有参考价值。     

荆江河段水沙条件与主流线特征关系研究

荆江河段的主流变化主要表现为弯曲分汊段的主支汉交替及单一弯道段深泓半径的变化,综合考虑两者关系,提出了能描述荆江分汉段及单一弯道段主流线特点的无量纲常数--弯曲特征数r,并针对同一河段分析了汛期平均流量、洪峰变差系数、年输沙量及输沙指数等水沙条件变化与主流线变化的对应关系.结果表明:汛期平均流量较小、水流相对饱和度低、来水来沙过程较为均匀使得滩槽高差较小,横断面向宽浅发展,从而减弱河道对水流的约束,弯曲特征数较小,主流顺直;反之主流向弯曲发展.