Facilitated discussions increase learning gains from dialectically localized animated educational videos in Niger

ABSTRACT

This study measured the knowledge transfer and appeal of information and communication technologies (ICTs) used to deliver education for sustainable development (ESD) content to farmers in Niger experiencing major crop losses from the insect pest Maruca vitrata. ICT-ESD content consisted of two dialectically localized and animated videos that address food security problems of cowpea insect herbivory and the shortage of integrated pest management strategies in rural Niger. Comparing pre-test/post-test knowledge transfer for both animated videos when either (1) watched alone (AVO), or (2) in conjunction with a facilitated group discussion prior to post-testing (AVD), results from 90 farmers in 3 rural Nigerien villages showed statistically significant knowledge transfer in both AVO and AVD groups and still greater gains in the AVD group. Importantly, while a majority of participants expressed a preference for learning from such animated videos and a willingness to share their new knowledge and the videos with others, this finding did not statistically significantly associate with education level, supporting the idea that AVO/AVD is an inclusive strategy for low-literate learners within developing-nation contexts. Recommendations and theoretical implications for ICT-ESD implementations in resource-limited areas are also discussed.     

When Does Communication Learning Need Hierarchical Multi-Agent Deep Reinforcement Learning

Abstract

Multi-agent systems need to communicate to coordinate a shared task. We show that a recurrent neural network (RNN) can learn a communication protocol for coordination, even if the actions to coordinate are performed steps after the communication phase. We show that a separation of tasks with different temporal scale is necessary for successful learning. We contribute a hierarchical deep reinforcement learning model for multi-agent systems that separates the communication and coordination task from the action picking through a hierarchical policy. We further on show, that a separation of concerns in communication is beneficial but not necessary. As a testbed, we propose the Dungeon Lever Game and we extend the Differentiable Inter-Agent Learning (DIAL) framework. We present and compare results from different model variations on the Dungeon Lever Game.     

煤矿5G分布式MIMO组网技术研究（增刊）

根据煤矿井下的安全防爆要求，天线的射频发射功率受到严格限制，导致煤矿5G的基站部署密度显著高于地面场景。为了解决由此引发的交叉覆盖问题，本文提出了煤矿5G分布式MIMO组网技术，利用分布在不同位置的天线实现对用户数据的联合并行发送，不仅避免了由交叉覆盖导致的乒乓切换等负面效应，还提升了边缘区域的信号覆盖效果。在乌兰木伦煤矿的300米采煤工作面内，利用分布式MIMO组网技术实现了5G信号的无边界覆盖，上行速率不低于500Mbps，保障了煤机数据的实时有效传输。     

三菱Q系列PLC串口自由通讯方法的探究

多种工业控制场合需要使用智能设备,并以串行通信将数据发送至上位机。三菱Q系列PLC无顺序通信方法仅支持接收“固定长度”与“变长度有固定结尾”两种数据对象,与发送“变长度无固定结尾”数据的智能设备不能妥善匹配。为此设计了一种Q系列PLC串口自由通信方法,该方法采用顺序控制程序实现了“变长度无固定结尾”数据接收、异常数据消除与通信模块故障自恢复,具有破除通信模块设定局限、可自行定义通信协议的特点。经实验其可同时支持多种智能设备,具有良好的适应性和通用性。     

基于物联网的智能室内定位送水系统设计

随着物联网技术的发展,机器人已广泛应用于生产和生活之中。自动送水机器人作为一种智能饮水系统,可应用于办公区域、医院、家庭等多种场所,智能化地为人类提供饮水服务。本文设计了一款智能室内定位送水系统,可以实现水杯定位、转向前行、自动添注水等功能。系统以UP Squared处理器为设计平台,扩展了UWB定位、Zigbee无线传输、陀螺仪、机械臂等功能模块。采用MPU6050 模块进行旋转角度感知,PID算法控制机器人旋转；基于电流磁效应和电磁感应定律感知水杯位置；采用超声波模块对出水口上升的高度和水杯中水位进行检测。通过实验测试了系统的定位、方向调整、测距、功耗等多项参数以及送水全过程,结果表明,系统具有定位准确、转向快速平稳和功耗低等特点,达到实际应用于室内智能定位送水的技术要求。     

网络与通信技术在计算机控制中的应用

在社会经济高速发展的支持下,我国网络与通信技术高速发展,并且在发展中逐渐实现了两种技术的结合应用,大大提升了网络与通信技术的应用价值。文章对网络与通信技术进行分析,研究网络与通信技术在计算机控制中应用的时代背景和具体应用,并对其未来发展进行了概述,以促进计算机控制领域的科学化发展。     

Design and investigations on a compact,UWB, monopole antenna with reconfigurable band notches for 5.2/5.8 GHz WLAN and 5.5 GHz Wi‐MAX bands

This article represents a microstrip line–fed novel circular monopole antenna with ultra‐wideband (UWB) characteristics. The compact antenna provides reconfigurable notches at WLAN (5.2/5.8 GHz) and Wi‐MAX (5.5 GHz) frequency bands. The band rejection is achieved by etching an open‐ended L‐shaped slot in the ground plane, which effectively mitigates the interference between WLAN, Wi‐MAX, and UWB systems with an effective patch area of 36.26%. The proposed antenna operates from 3.05 to 12.11 GHz with VSWR 2 except at stopband (3.89‐5.93 GHz) to filter the WLAN and Wi‐MAX signals. The simulated return loss, gain, and radiation pattern of the proposed antenna has been experimentally verified with the fabricated one which holds a good agreement.     

用于矿山等极端环境中的高精度定位算法

高精度室内定位技术在矿山、建筑、施工等多种极端环境下都有需求。基于超宽带通信(Ultra Wideband,UWB)的室内定位技术能够提供较高的定位精度,但超宽带信号易受到障碍物的干扰,并且在类似矿山等极端环境中,障碍物不可避免。因此,超宽带非视线传输(Non-Line-of-Sight,NLoS)测距成为当前的一个研究热点。当前研究大多集中在识别和消除非视线传输对超宽带测距的影响上,实际应用中,大多数情形下超宽带信号根本无法穿透障碍物,会导致定位标签只能够与2个或1个信标节点通信,但完成三边定位至少需要3个信标节点。为此,提出了一种基于目标行为分析的定位算法,该算法能够在短时间内仅剩余一个信标节点与标签通信时,也可实现高精度定位。该算法以超宽带通信为基础,使用信号飞行时间(Time of Flight,TOF)算法测距并定位。通过分析信号正常时的目标运动轨迹来判断其速度和方向,当信号不正常时(可通信的信标节点减少),可利用预测的速度和方向参数来实现辅助定位。将该算法部署在一个基于超宽带定位的系统中进行了测试,结果表明:当能够与标签通信并完成TOF算法的信标节点数量少于3个时,基于NLoS传输识别和消除的算法无法完成定位,而基于目标行为分析的定位算法依然能够实现定位,在单信标节点区域的平均定位误差为0.93 m,最大误差为1.41 m,在2个信标节点测距的区域,平均定位误差为0.64 m,最大误差为1.2 m。     

以用户为中心的可见光通信协作传输中训练资源分配算法

以用户为中心的可见光通信协作传输是近年来出现的新架构,这导致虚拟小区之间出现重叠。为避免导频污染问题,每个虚拟小区中的光接入点(AP)或者虚拟小区中选择相同AP的用户发送的训练序列应该是正交的。针对可见光通信中以用户为中心的协作网络,研究训练资源的正交分配问题,提出了一种新的导频分配算法,联合导频分配和用户选择问题,以期最大限度地增加虚拟小区内可被接入的用户数。分析和仿真结果表明,该导频分配方案可以有效改善导频污染问题,提高训练资源利用率,并且相比已有的导频分配方案,性能有所改进。