一种考虑时钟同步问题的多AUV协同定位算法

在多自主水下航行器（multi-AUVs）协同导航系统中,领航AUVs配备高精度导航定位设备,跟随AUVs配备低精度导航设备,领航、跟随AUVs均配备水声通信设备,跟随AUVs利用领航AUVs的广播信息获得其与领航者间的距离。本文针对领航AUVs与跟随AUVs问的时钟不同步问题,给出了AUV时钟相对偏移与相对漂移模型,并将跟随AUVs的时钟偏差作为未知量,提出了一种考虑时钟同步问题的multi-AUVs协同定位算法。仿真结果表明,该算法不仅可以大幅度提高跟随AUVs的协同定位精度,而且能够随时对跟随AUVs时钟误差进行估计,有效地提高了multi-AUVs协同导航系统性能。     

空战自主机动决策问题建模

描述了自主空战机动决策问题,系统研究了自主机动决策各个环节,建立了子环节数学模型,构建了整个自主机动决策模型,并通过11个基本机动动作仿真验证了模型的有效性。     

基于Biharmonic插值的海底地形可视化仿真

由于电子海图中只包含海洋环境的矢量数据,并未给出海底地形相关信息。本文利用IS08211类库,提取S-57电子海图原始文件的矢量水深数据,依据这一组水深数据进行Biharmonic曲面样条插值,计算出一组曲面上的网格点处的坐标数据,从而实现对该海区内海底地形的可视化仿真。同时利用插值后的坐标数据,进行等深线绘制仿真,将仿真结果与专业电子海图软件打开同一张海图进行对比以及误差分析,结果表明,使用捅值数据构建地形的正确性,规则分布的插值水深数据可用于自主式水下航行器（AUV）的自主路径规划。     

人本主义心理学与英语听力自主学习

从人本主义心理学的基本理论出发,阐述罗杰斯人本主义学习论的主要观点.在此基础上,分析人本主义学习论与英语自主学习的关系,并对人本主义学习论应用于英语听力自主学习进行初步的探讨.     

一种利用单信标修正AUV定位误差的方法

针对配置有捷联惯导（SINS）／多普勒速度仪（DVL）／深度传感器组合导航定位系统的自主水下航行器（AUV）的定位误差随时间增大,以及采用GPS修正定位误差引起的AUV隐蔽性降低等问题,提出了一种利用水下固定单信标修正SINS／DVL／深度传感器组合定位误差的方法。该方法首先利用水声测距原理测量出AUV与水下固定单信标的距离,然后基于空间几何关系计算出AUV的实时位置,最后通过卡尔曼滤波连续修正AUV的定位误差。仿真结果表明,该方法可以有效减小AUV的定位误差,有较好的工程应用价值。     

龙岗区生活垃圾分类现状及对策研究

通过调查深圳龙岗现有城市生活垃圾分类现状和收运模式,分析其存在的问题和成因,提出深圳市龙岗区生活垃圾分类处理的策略。     

Reconstituted versus dry alfalfa hay in starter feed diets of Holstein dairy calves: Effects on feed intake,feeding and chewing behavior,feed preference,and health criteria

We investigated the effect of reconstitution of alfalfa hay on feeding and chewing behavior, sorting activity, and health status using 20 neonate Holstein male calves (3 d of age; 40.3 ± 1.30 kg of body weight) that were assigned randomly to 2 treatments, a starter feed containing either 10% dry (AH) or reconstituted alfalfa hay (RAH), each consisting of 10 calves. Alfalfa hay was reconstituted with water 24 h before feeding to achieve a theoretical dry mater (DM) content of 20%. Both starter diets had the same ingredients and nutrient compositions but differed in their DM content (90.9 vs. 66.6% DM for AH vs. RAH, respectively). Calves were weaned on d 50 and remained in the study until d 70. Reconstitution of alfalfa hay increased the percentage of particles retained on 8- and 1.18-mm sieves, but reduced feed materials retained on the bottom pan. Feeding RAH tended to increase meal frequency (preweaning) and increased meal duration (pre- and postweaning), and thereby increased time devoted to eating without affecting nutrient intake. Calves fed RAH tended to have lower eating rate during the pre- and postweaning periods. Tendencies to concurrent increase in rumination frequency and rumination duration in calves fed RAH increased time devoted to ruminating during the preweaning period; however, a tendency to longer rumination duration did not affect ruminating time during the postweaning period. Calves fed RAH spent less time resting and standing and more time drinking during the postweaning period. Non-nutritive oral behaviors were not affected by treatment during the pre- and postweaning period. Feeding RAH decreased sorting of particles retained on 8-mm sieve compared with AH; however, calves in both treatment groups sorted for particles retained on 8- and 1.18-mm sieves and against the feed materials retained on the bottom pan. Crude protein and neutral detergent fiber intakes of particles retained on the both 8- and 1.18-mm sieves increased in calves fed RAH versus AH, with no changes in intake of nutrients retained on the bottom pan. Calves fed AH were more susceptible to develop diarrhea (odds ratio = 2.02) and pneumonia (odds ratio = 4.74) and thereby had lower chances of being treated. We found no difference between treatment groups for frequency and medication days of diarrhea; however, calves fed RAH experienced fewer days with diarrhea. Furthermore, frequency and number of days with pneumonia and administration of medication were greater for calves fed AH compared with calves fed RAH. Blood concentrations of total protein and globulin tended to be higher in calves fed RAH compared with calves fed AH. Overall, feeding RAH increased time devoted to eating by increasing meal frequency and meal duration but did not affect feed intake due to lower eating rate. Calves in both treatment groups exhibited feed sorting at the extent to which they balanced intake of nutrients and met their nutritional needs. Calves, in general, were healthy, but it seems that feeding a diet containing reconstituted alfalfa hay has a potential health-promoting effect, possibly through reducing diet dustiness and improving immune status.     

Subspace Clustering for Situation Assessment in Aquatic Drones: A Sensitivity Analysis for State-Model Improvement

Abstract

In this paper, we propose the use of subspace clustering to detect the states of dynamical systems from sequences of observations. In particular, we generate sparse and interpretable models that relate the states of aquatic drones involved in autonomous water monitoring to the properties (e.g., statistical distribution) of data collected by drone sensors. The subspace clustering algorithm used is called SubCMedians. A quantitative experimental analysis is performed to investigate the connections between i) learning parameters and performance, ii) noise in the data and performance. The clustering obtained with this analysis outperforms those generated by previous approaches.     

基于RobotStudio的芯片智能分拣生产线设计

为了缩短芯片智能分拣生产线开发周期,利用虚拟仿真技术在RobotStudio软件中搭建仿真工作站;该工作站以ABB IRB360并联工业机器人为控制核心,利用Solidworks建模软件完成相关模型建立,利用RobotStudio软件的Smart组件、机械装置等功能实现芯片下料、芯片传输、相机检测等过程,设计工业机器人的路径和程序完成分拣工作;最后将仿真工作站的代码直接下载至现场工业机器人,并根据仿真节拍调节现场各模块工作速度,实现芯片的智能分拣;实验结果表明,工业机器人能够根据相机的引导正确且高效地分拣芯片.     

Impacts of an ATF cladding on neutronic performances of the soluble-boron-free ATOM core

This article is mainly concerned with the impacts of various accident tolerant fuel (ATF) claddings on neutronics performances of a soluble-boron-free (SBF) small modular reactor (SMR) core. There are two ATF cladding concepts which are evaluated here: (a) coating Zircaloy-4 cladding with a thin layer of Cr or Cr alloys; (b) high-strength and oxidation-resistant claddings: stainless steel and FeCrAl. Comparisons between Zircaloy-4 and ATF claddings are done in terms of the cycle length, discharge burnup, pin peaking factor (PPF), burnup reactivity, and spectral change. Moreover, the ATF claddings are also compared in view of the rim effect, neutron absorption by the cladding and He production in the cladding. In addition, a linear reactivity model is used to estimate the required U-235 enrichment so that the cycle length with ATF claddings should be equivalent to that with the reference Zircaloy-4 case. Furthermore, impacts of a selected ATF cladding are then analyzed in a centrally shielded burnable absorber (CSBA)-loaded FA in terms of PPF, burnup reactivity, and spectral change. Based on the CSBA-loaded FA analysis, a minor modification of burnable absorber loading strategy in the SBF autonomous transportable on-demand reactor module core is proposed to adopt the selected ATF cladding without compromising the core performance. The lattice calculations are done using the Monte Carlo Serpent 2 code with the ENDF/B-VII.1 nuclear library, while the 3-D multi-physics core calculations are performed using a Monte Carlo-diffusion hybrid procedure.