线上线下结合的实时手势跟踪系统

手势识别跟踪一般采用线下训练分类器,不能有效检测跟踪形变的手势,针对手势形变及在窗口的暂时性消失等问题,提出了一种通过线下训练结合线上提取样本对分类器进行训练的检测方法,同时采用跟踪一检测一学习(TLD)的方法不断对跟踪器的结果进行纠正.试验结果表明,本算法对手势形变、短暂消失具有很好的适应性,与TLD算法相比较具有更好的稳定性.     

Multiple human tracking in high-density crowds

In this paper, we introduce a fully automatic algorithm to detect and track multiple humans in high-density crowds in the presence of extreme occlusion. Typical approaches such as background modeling and body part-based pedestrian detection fail when most of the scene is in motion and most body parts of most of the pedestrians are occluded. To overcome this problem, we integrate human detection and tracking into a single framework and introduce a confirmation-by-classification method for tracking that associates detections with tracks, tracks humans through occlusions, and eliminates false positive tracks. We use a Viola and Jones AdaBoost detection cascade, a particle filter for tracking, and color histograms for appearance modeling. To further reduce false detections due to dense features and shadows, we introduce a method for estimation and utilization of a 3D head plane that reduces false positives while preserving high detection rates. The algorithm learns the head plane from observations of human heads incrementally, without any a priori extrinsic camera calibration information, and only begins to utilize the head plane once confidence in the parameter estimates is sufficiently high. In an experimental evaluation, we show that confirmation-by-classification and head plane estimation together enable the construction of an excellent pedestrian tracker for dense crowds.     

Design and optimization of buck and double buck converters by means of geometric programming

This paper describes a new method for determining the optimal components values and switching frequencies of buck DC–DC converters. First, we revisit some concepts of the optimization technique named geometric programming. Then, we observe that the problem of converter designing can be modeled by means of an objective function and certain constraints which can be written in a specific form known as the posynomial form. The constraints involve expressions that depend on magnitudes such as efficiency, bandwidth, and current and voltage ripples.     

超低温保存箱复叠式制冷循环特性分析

在理论分析和计算的基础上,选择R404A/R508作为复叠制冷循环的制冷剂工质对,通过分析复叠式制冷系统的高、低温级制冷循环性能系数（COP）与各自的蒸发温度、冷凝温度之间的关系,在整机COP最大化和高、低温级压缩比相等的原则下,确定了复叠式制冷系统最佳中间温度以及系统工作的状态点.     

基于逐次逼近遗传算法的梯级水库优化调度

利用传统遗传算法求解水库优化调度问题时,经过遗传操作产生的新个体可能是不可行解,因此需要对其进行修正.但在梯级水库调度中,由于各时段间、水库间存在的水力电力联系,使这种修正变得复杂困难.鉴于此,提出了逐次逼近遗传算法(GASA),它可在包含不可行解的空间中寻优,并通过搜索空间的不断改变,逐渐逼近最优解.最后通过一个算例,并与离散微分动态规划法(DDDP)和逐步优化法(POA)的优化结果进行比较,说明了该方法的可行性与有效性.     

黄河干流梯级开发构架与泥沙控制布局研究

大量实测资料分析表明,黄河流域主要的产沙区间为河口镇至潼关区间,黄河支流按入黄沙量大小排序为渭河、无定河、窟野河、北洛河、祖厉河、皇甫川、延河、清涧河、洮河、汾河等。对黄河干流36个梯级开发工程、13条主要来沙支流224座水库研究表明,干流龙羊峡、刘家峡、大柳树、碛口、古贤、三门峡、小浪底等七大骨干工程的总库容为944.97亿m3,总有效库容为472.26亿m3,拦沙库容为466.65亿m3,分别占36个梯级水库拦沙总库容的91%9、3%、90%。小浪底水库虽然具有巨大的拦沙库容,但是其上游水库或者未建、或者淤满、或者位于来沙区上游,因此其拦沙压力巨大,剩余拦沙年限仅10余年。小浪底水库淤满后,黄河泥沙将失去控制,会对黄河下游防洪构成危害。     

梯级电站建设对水质的影响

采用一维水动力数学模型和水质数学模型,对梯级电站建设前后的CJ江干、支流的水质变化进行研究,预测CJ江2020年5个梯级电站建设后干流水质主要参数的变化情况。结果表明,各梯级电站水库蓄水后各坝址处平均DO质量浓度将较建库前略有下降,BOD5和NH3-N的质量浓度呈下降趋势,TP质量浓度变化较小。     

梯级水电站群优化调度算法研究

根据梯级水电站群远程集控调度的特点,研究了适用于梯级水电站群的优化调度算法。讨论了梯级水电站群优化调度准则,对几种典型优化算法的适应性和局限性进行了分析比较。结果表明,在流域梯级电站数量较少时可采用动态规划算法,在流域梯级电站规模较大时可采用基于遗传算法的改进型优化算法。按照流域梯级水电站的实际情况采用适应的优化算法,才能发挥梯级水电站远程集控优化调度系统的优势。     

Short-term power generation scheduling rules for cascade hydropower stations based on hybrid algorithm

Power generation dispatching is a large complex system problem with multi-dimensional and nonlinear characteristics. A mathematical model was established based on the principle of reservoir operation. A large quantity of optimal scheduling processes were obtained by calculating the daily runoff process within three typical years, and a large number of simulated daily runoff processes were obtained using the progressive optimality algorithm (POA) in combination with the genetic algorithm (GA). After analyzing the optimal scheduling processes, the corresponding scheduling rules were determined, and the practical formulas were obtained. These rules can make full use of the rolling runoff forecast and carry out the rolling scheduling. Compared with the optimized results, the maximum relative difference of the annual power generation obtained by the scheduling rules is no more than 1%. The effectiveness and practical applicability of the scheduling rules are demonstrated by a case study. This study provides a new perspective for formulating the rules of power generation dispatching.     

IIC总线主发主收模式运用

在数据传输速率要求不是很高的前提下,采用IIC总线的系统进行数据采样和传输是个很好的方案。将具有IIC接口的主、从器件,通过一根数据线和一根时钟线将不同地址的单通道模数转换芯片和数据传输芯片级联在一起,构建多点数据采集和传输系统,实现多通道模数转换芯片和数据传输芯片的功能。再配合扩展芯片的使用可以扩展总线的传输距离。通过对IIC总线典型的工作模式主发、主收的分析,该方法能满足绝大多数情况多点数据采集和传输的工作。