一种基于实时几何测距的船桥主动防撞方法

本文提出一种基于实时几何测距的船桥主动防撞方法。该方法对船的改动量甚微,仅需维持多项距离矩阵,通过告警逻辑矩阵进行展示与告警,能起到很好的船桥防撞提示效果。     

车辆高速避让路径跟踪控制策略

建立车辆动力学模型,研究车辆在高速避让工况下的路径跟踪控制策略。基于自抗扰控制设计车辆横摆角速度以及道路曲率2种不同的路径跟踪控制器;设计基于车辆偏航位移和偏航角度加权的线性二次最优控制器;对3种控制器控制效果进行仿真验证,分析路径跟踪侧向位移误差、侧向加速度、前轮转向角以及偏航角度变化。越野车实车测试结果表明,路径跟踪控制策略正确。     

A multilevel sampled‐data approach for resilient navigation and control of autonomous systems

Autonomous systems are rapidly becoming an integrated part of the modern life. Safe and secure navigation and control of these systems present significant challenges in the presence of uncertainties, physical failures, and cyber attacks. In this paper, we formulate a navigation and control problem for autonomous systems using a multilevel control structure, in which the high‐level reference commands are limited by a saturation function, whereas the low‐level controller tracks the reference by compensating for disturbances and uncertainties. For this purpose, we consider a class of nested, uncertain, multiple‐input–multiple‐output systems subject to reference command saturation, possibly with nonminimum phase zeros. A multirate output‐feedback adaptive controller is developed as the low‐level controller. The sampled‐data (SD) design of this controller facilitates the direct implementation on digital computers, where the input/output signals are available at discrete time instances with different sampling rates. In addition, stealthy zero‐dynamics attacks become detectable by considering a multirate SD formulation. Robust stability and performance of the overall closed‐loop system with command saturation and multirate adaptive control are analyzed. Simulation scenarios for navigation and control of a fixed‐wing drone under failures/attacks are provided to validate the theoretical findings.     

基于入位基准线的避死区自动泊车路径规划

为避免自动泊车过程中出现泊车死区，提出一种在车位外部汽车自动向前行驶至前进水平线的轨迹计算方法；为了减小泊车所需的车位长度，研究了由前进水平线倒车泊入车位，并保证该泊车轨迹经过入位基准线的方法。通过确定出的几个必须经过的定点坐标，利用插值样条理论与几何数学，确定出汽车在车位外部的泊车路径及其函数，且该函数具有唯一性，因此减少了自动泊车过程中系统不断进行反馈与纠正的计算过程。通过实验车的模拟验证，证明了路径规划的正确性。利用CarSim软件进行泊车过程的运动仿真，并对绘制出的轨迹线进行分析，结果表明该方法能控制汽车自动前进至非泊车死区位置，并可以减少对泊车所需车位长度的要求。     

A thermal-aware VM consolidation mechanism with outage avoidance

Efficient energy and temperature management techniques are essential elements for operators of cloud data centers. Dynamic virtual machine (VM) consolidation using live migration techniques presents a great opportunity for cloud service providers to adaptively reduce energy consumption and optimize their resource utilization. In recent studies, power consumption readings of individual physical hosts were chosen as the main monitoring parameters in their allocation policies, whereas very few have considered host temperature, which has shown to have a negative impact on server reliability, as a migration criterion. In this work, a thermal-aware VM consolidation mechanism is proposed for resource allocation optimization and server reliability assurance. We consider the variability in host temperature as a migration criterion to avoid outage incidents via having better VM consolidations. Extensive simulation results obtained from CloudSim show the promising performance of the proposed mechanism in energy saving while reducing the number of server outage incidents due to fluctuations in host temperature.     

H2NG environmental-energy-economic effects in hybrid energy systems for building refurbishment in future National Power to Gas scenarios

In order to comply to the ambitious targets of European Hydrogen Strategy, Member States will strongly encourage the deployment of Power-to-Gas (PtG) technologies. A significant fraction of produced green hydrogen will be injected into the existing natural gas networks, and the end-users will be served by Hydrogen enriched Natural Gas blends (H₂NG). The aim of this paper is to analyse the H₂NG effects on technical, economic and environmental parameters of hybrid energy systems for building refurbishment. Three hybrid energy systems for the existing plants replacement have been proposed, dynamically simulated and compared with the separate generation. Fuel supply has been simulated by varying the H₂ volumetric fraction in a range between 0 and 20%vol. The H₂NG blend employment will allow greater primary energy savings and avoided emissions. However, if the levelized cost of hydrogen (LCOH) due to electrolysis does not decrease, those benefits will be offset by a lower economic competitiveness.     

煤矿地面轨道运输矿车自动避障技术研究

介绍了煤矿地面轨道运输矿车自动避障技术。首先介绍了基于雷达的矿车前方障碍物检测技术及其相关算法,然后详细介绍了基于机器视觉的矿车前方障碍物检测系统和常用的图像处理方法以及相关的算法,最后介绍了雷达和机器视觉融合的障碍物检测技术在煤矿地面轨道运输矿车自动避障过程中的应用。     

The mediating role of problematic social media use in the relationship between social avoidance/distress and self-esteem

The number of social media users in Bangladesh is increasing in every year. Young people – mainly college and university students – are the heavy users of it. Problematic social media use (PSMU) has received increasing research attention over the past decade. However, there are very few studies concerning PSMU in Bangladesh. The present study examined the role of PSMU in the relationship between social avoidance/distress and self-esteem. The study comprised a sample of 370 university students from the University of Chittagong (Bangladesh). Participants were administered a survey including questions regarding socio-demographics, the Bergen Social Media Addiction Scale (BSMAS), the Rosenberg Self-Esteem Scale (RSES), and the Social Avoidance and Distress Scale (SADS). Results showed that PSMU partially mediated the relationship between social avoidance/distress and self-esteem, while social avoidance/distress predicted the level of self-esteem. However, PSMU had a non-significant influence on the relationship between these two variables while self-esteem predicted social avoidance/distress.     

我国西北矿产资源开发利用的风险规避研究

在对西北矿产资源开发的环境风险和资源风险进行分析的基础上，从系统和整体的角度，提出了5种主要的矿产资源风险规避策略。第一，走绿色矿业的道路，规避环境风险；第二，走企业集团化道路，规避市场风险；第三，走技术链条化道路，规避资源风险；第四，走城、矿耦合化道路，规避“矿枯城衰”风险；第五，加大矿产资源勘察力度，提高抗风险的能力。     

A concurrent control architecture for autonomous mobile robots using Asynchronous Production Systems

The quest for efficient real-time response by autonomous robots in hazardous environments necessitates not only fast computational schemes in expert systems but also requires insights on high performance data structures and concurrent algorithms that lead to elegant problem-solving methods in the AI discipline. towards this objective, this paper presents an Asynchronous Production System (APS) of architecture capable of monitoring and processing real-time information.