基于雨雾分离处理和多尺度网络的图像去雨方法

雨带来的雨条纹和雨雾会降低户外拍摄图像的质量,为了去除雨雾对图像的影响,提出了一种基于雨雾分离处理和多尺度卷积神经网络的图像去雨方法。首先利用导向滤波将雨线和图像细节信息提取到高频层,雨雾和背景信息则分离到低频层;然后构建多尺度卷积神经网络来去除高频层中的雨线,网络中融入多个稠密连接模块以提升特征提取的准确性;其次构建多层特征融合的轻量级去雾网络来去除低频层中的雨雾,采用参数一体化结构避免了估计多个大气散射模型参数导致的次优解;最后再结合处理后的高低频结果还原出清晰图像。在多个合成的雨雾数据集以及真实自然场景图像上进行测试,定性和定量结果表明,提出的方法在去除雨雾影响的同时较好地保留了色彩信息,和近年的算法相比,图像结构相似性约提升了0.02~0.08,图像峰值信噪比约提升了0.2~3.5 dB。     

红灯信号渐消方式对时距估计和情绪体验的影响

目的通过调整红灯信号的渐消方式来缩短行人对红灯时长的时距估计,提升情绪水平,创造更好的人机互动体验。方法实验通过口头估计法对红灯刺激信号的形状、消减速度和分割数目/频率不同水平的测试,来研究被试的时距估计和轻松值反馈。结果发现形状和速度的主效应显著,倒梯形和减速消减在诸多形状与速度水平中能够创造最短的时距估计及轻松值,而矩形和匀速消减表现最差。且相比刺激的外框形状变化,分割数目变化带来的视觉单元面积变化并不能显著影响时距判断。结论刺激的3种因素以及因素间的关联程度对被试的时距估计和情绪水平产生显著的影响。     

基于GPU粒子系统的大规模场景高效雨雪实时模拟

粒子系统实现的雨雪效果能有效增强三维场景的真实感,传统基于中央处理器（CPU）运算模拟的粒子系统占用了大量CPU运算时间,难以达到实时模拟的要求。为此提出了一种基于图形处理器的（GPU）运算的粒子系统来模拟的雨雪场景。该方法通过在GPU中重复使用消亡粒子在视点坐标系内生成新粒子,并在几何着色器中将粒子的点坐标转换为矩形坐标,将CPU从复杂庞大的几何运算中解放出来,从而大幅增加了场景绘制的微粒数,使雨雪场景模拟的实时性和逼真度得到增强。     

Heuristics for the multi-period orienteering problem with multiple time windows

We present the multi-period orienteering problem with multiple time windows (MuPOPTW), a new routing problem combining objective and constraints of the orienteering problem (OP) and team orienteering problem (TOP), constraints from standard vehicle routing problems, and original constraints from a real-world application. The problem itself comes from a real industrial case. Specific route duration constraints result in a route feasibility subproblem. We propose an exact algorithm for this subproblem, and we embed it in a variable neighborhood search method to solve the whole routing problem. We then provide experimental results for this method. We compare them to a commercial solver. We also adapt our method to standard benchmark OP and TOP instances, and provide comparative tables with state-of-the-art algorithms.     

网页驻留时间约束的用户访问序列挖掘

对Web用户的访问序列进行分析,可以发现用户的爱好、兴趣、习惯等因素,为Web网站的升级修正提供必要的信息支持,提出一种通过对用户访问序列进行分析的数据挖掘方法,该方法采用网页驻留时间为参数来约减会话序列中的网页数,压缩频繁访问序列的规模。实验结果表明,该算法可以降低挖掘成本,为Web用户的商业数据挖掘提供有益的借鉴。     

Ka频段卫星通信上行链路自适应功率控制

为提高Ka频段（30GHz／20GHz）卫星通信系统上行链路功率控制的可靠性,提出一种上行链路自适应功率控制算法。该方法基于自回归滑动平均模型,能由测量到的下行链路降雨衰减值预测出上行链路的降雨衰减值,从而提高功率控制精度。仿真结果表明,该方法对降雨衰减具有较好的补偿效果。     

Moving-in-pulse duration model-based target integration method for HSV-borne high-resolution radar

Hypersonic vehicles (HSVs) offer great advantages over airplanes and satellites, owing to their hypersonic speeds and flexible trajectories. However, HSV-borne radar may suffer from performance degradation if traditional target integration methods with stop-and-go (SAG) approximation are applied; this is especially true for high resolution radar and applications that utilize long-time coherent integration. In this paper, we consider the effects of moving-in-pulse duration (MPD) to derive an HSV-borne radar signal model without SAG approximation by specifically characterizing platform motion during the transmission and reception of a pulse. An explicit formula for wavenumber domain echo is derived using the 2-D joint stationary phase method. To mitigate the pulse-dependent echo distortion induced by the MPD effect, a target integration method based on the omega-K algorithm is proposed; this method employs revised filters for bulk focusing and revised Stolt interpolation for differential focusing to improve the overall focusing quality. The paper discusses the ambiguity functions of in-range MPD echo models, and describes the performance metrics for the integration results in both dimensions, including impulse response width (IRW), peak sidelobe ratio (PSLR), and integrated sidelobe ratio (ISLR). Simulation results have verified the effectiveness of the proposed method in MPD circumstances.     

Redefining the Water Poverty Index

Abstract

The Water Poverty Index (WPI) of arid and semiarid climatic zones is redefined by introducing the contribution of rainfed agriculture into WPI calculations and by making the WPI equation account for diversities in climatic conditions within arid and semiarid zones and for recycled household water used in irrigation.