ARCE风险处理计划测量模型的设计与实现

提出用于定量测量风险处理计划有效性的ARCE模型,从理论上证明该模型的正确性.以组织信息安全资产的风险值和已实施控制措施为输入,通过中间变量矩阵得到风险处理计划有效性矩阵的模型量化指标体系.模型实现过程包括风险评估、风险处理、定量测量、安全事件管理和报表5个部分,并给出实施流程.应用结果表明,该模型能准确测量风险处理计...     

Improving risk management: moving from risk elimination to risk avoidance

This study has examined software reliability using a risk management framework to analyze popular risk management models with regard to their emphasis on risk avoidance. Too often, risk reduction occurs late in the software development life cycle when changes are costly and less effective. We suggest that early risk avoidance techniques, like the cleanroom software development process and its sub-process of software inspections, leads to superior products. Our approach is different from the current mainstream approach of testing to eliminate errors because we propose using risk models that emphasize preventive risk management early in development. We argue that the use of risk avoidance leads to benefits that far outweigh the cost of implementation.     

An evaluation of EU legislation concerning risk assessment and preventive measures in occupational safety and health

The European Council Directive 89/391/EC of 12 June 1989 is concerned with the introduction of measures to encourage improvements in the occupational safety and health. For example, it deals with risk assessment and preventive measures. The Finnish legislation enacts the risk assessment and prevention measures in a similar way as the EU Directive 89/391/EC. The aim of this study was to examine: 1) the implementation of risk assessment process as a part of OSH management, and 2) the effectiveness of the OSH legislation concerned with risk assessment. The quantitative method involved an online questionnaire. The respondents were employers (N = 1478), workers (N = 1416) and occupational care (OHC) professionals’ units (N = 469). Three quarters of the employer respondents and two thirds of the workers and OHC service providers felt that the EU legislative provisions have promoted the engagement of the management. According to the study, improvement is needed in ensuring the cooperation between employers and workers. The combined variables of Risk Assessment Process revealed positive impacts both on Cooperation and Management Measures and on the Concrete Preventive Measures among the employers and the workers. The combined variables of Use of Documents of Risk Assessments highlighted positive impacts on both the Exploiting of Results of Risk Assessments in Planning and Management and on the Exploiting of Results of Risk Assessment in Cooperation and Technology.     

基于超声波传感器的脑控轮椅避障系统的研究

针对脑控轮椅行驶时因用户脑电信号的不稳定性可能引起碰撞事故发生的现象,提出了一种避障方法,并设计了多路超声波传感器避障系统及避障提示反馈界面;反馈界面上实时显示的提示信息将辅助用户做出有效的避障决策;当用户采用脑电自主控制轮椅运行时,若无法成功避障,则该避障系统立即启动紧急停车功能以避免与障碍物发生碰撞,保证了脑控轮椅用户的人身安全;实验结果表明:当把安全区域临界值、前后及左右紧急停车距离临界值分别设置为500mm、400mm和200mm时,该超声波传感器避障系统稳定性好、实时性强,能够满足脑控轮椅的用户安全导航的需要.     

Artificial Force Field for Haptic Feedback in UAV Teleoperation

The feedback upon which operators in teleoperation tasks base their control actions differs substantially from the feedback to the driver of a vehicle. On the one hand, there is often a lack of sensory information; on the other hand, there is additional status information presented via the visual channel. Haptic feedback could be used to unload the visual channel and to compensate for the lack of feedback in other modalities. For collision avoidance, haptic feedback could provide repulsive forces via the control inceptor. Haptic feedback allows operators to interpret the repulsive forces as impedance to their control deflections when a potential for collision exists. Haptic information can be generated from an artificial force field (AFF) that maps environment constraints to repulsive forces. This paper describes the design and theoretical evaluation of a novel AFF, i.e., the parametric risk field, for teleoperation of an uninhabited aerial vehicle (UAV). The field allows adjustments of the size, shape, and force gradient by means of parameter settings, which determine the sensitivity of the field. Computer simulations were conducted to evaluate the effectiveness of the field for collision avoidance for various parameter settings. Results indicate that the novel AFF more effectively performs the collision avoidance function than potential fields known from literature. Because of its smaller size, the field yields lower repulsive forces, results in less force cancellation effects, and allows for larger UAV velocities. This indicates less operator control demand and more effective UAV operations, both expected to lead to lower operator workload, while, at the same time, increasing safety.     

未知环境下多AUV协同避障方法研究

针对多AUV（autonomous underwater vehicle）系统在未知环境中进行路径规划时难以兼顾避障与编队的问题,提出了一种基于领航—跟随者与行为的多AUV协同避障方法。首先,通过构造碰撞危险度及偏离目标评价函数,设计了AUV局部路径规划方法;在此基础上,结合编队控制方法,分别为领航者和跟随者设计不同的行为以及行为选择模式。半物理仿真实验结果表明,该算法能够实现多AUV系统在未知环境中的协同避障,且队形偏离度与恢复队形时间优于传统多机器人避障算法。实验结果证明了该算法的可行性与有效性。     

Supply chain system design integrated with risk pooling

This paper considers the location, production–distribution and inventory system design model for supply chain for determining facility locations and their capacity. Risk pooling effect, for both safety stock and running inventory (RI), have been incorporated in the system to minimize the supply chain cost along with determining facility location and capacity. In order to study the benefit of risk pooling for safety stock and RI two cases have been considered, first when retailers act independently and second when DCs-retailers work jointly. The model is formulated as mixed integer nonlinear problem and divided into two stages. The first stage determines the optimal locations for plants and flow relation between plants-DCs and DCs-retailers. At this stage the problem has been linearized using piece-wise linear function. Second stage enumerates the required capacity of opened plants and DCs. The first stage problem is further divided in two sub-problems using Lagrangean relaxation. First sub-problem determines the flow relation between plants and DCs whereas; second sub-problem determines the DCs- retailers flow. Solution of the sub-problems provides the lower bound for the main problem. Computational results reveal that main problem is within the 8.25% of the lower bound and significant amount of cost reduction can be achieved for safety stock and RI costs when DC-Retailer acts jointly.     

基于GQM模型的工业控制系统风险评估方法

风险评估是保证工业控制系统安全的重要机制，当前，信息安全和功能安全的耦合越来越紧密，考虑到不同组织的业务目标和运营环境多样化程度高，工控系统信息安全风险评估应紧密结合业务目标。基于目标-问题-度量（GQM）模型，从目标确定、问题描述、度量指标定义工控系统风险评估流程，以工控系统所承载的业务目标为指引，基于风险场景模型提出问题，围绕提出的问题收集信息，根据收集的信息和数据对度量指标进行关联分析和评价。最后，以PLC风险评估为实例，具体说明和验证了基于GQM模型的工业控制系统风险评估方法的有效性。     

基于DBN的特种车辆前向防撞推理模型

针对特种车辆在动态环境中的前向碰撞风险评估问题,对特种车辆前向碰撞风险的自然因素、驾驶员行为特征等进行研究,并对固定的车辆安全防撞距离阈值进行改进,提出了一种基于动态贝叶斯网络的前向防撞推理模型。该模型将自车与周围环境的位置关系、环境关系、驾驶员行为等因素进行融合,一旦周围环境发生变化,该模型可以及时评估前向风险,并与静态贝叶斯网络的前向推理模型进行对比分析。仿真实验验证了该前向防撞推理模型的可行性和有效性。     

Risk assessment for a video surveillance system based on Fuzzy Cognitive Maps

For various IT systems security is considered a key quality factor. In particular, it might be crucial for video surveillance systems, as their goal is to provide continuous protection of critical infrastructure and other facilities. Risk assessment is an important activity in security management; it aims at identifying assets, threats and vulnerabilities, analysis of implemented countermeasures and their effectiveness in mitigating risks. This paper discusses an application of a new risk assessment method, in which risk calculation is based on Fuzzy Cognitive Maps (FCMs) to a complex automated video surveillance system. FCMs are used to capture dependencies between assets and FCM based reasoning is applied to aggregate risks assigned to lower-level assets (e.g. cameras, hardware, software modules, communications, people) to such high level assets as services, maintained data and processes. Lessons learned indicate, that the proposed method is an efficient and low-cost approach, giving instantaneous feedback and enabling reasoning on effectiveness of security system.     

基于LabVIEW的汽车防撞报警系统的设计

针对交通安全问题,设计了一种基于虚拟仪器的汽车防碰撞报警系统。给出了系统硬件、软件的设计方法和主要实验数据。该系统采用LabVIEW7.0编程,配合FMCW雷达传感器和高性能数据采集卡,可实现对前方车辆距离、速度的动态监测,当预见到有碰撞危险时,自动发出警示信息,帮助驾驶员及时刹车,避免碰撞事故发生。实测结果证明了系统的有效性。     

拥塞窗口自适应的TCP拥塞避免算法

针对TCP Reno拥塞避免阶段拥塞窗口增长不够平滑的缺陷,在研究分析TCP Reno拥塞控制算法的基础上,提出一种基于拥塞窗口自适应调整增长因子的拥塞避免新算法——在拥塞避免阶段采用压缩特性的对数增长因子函数。在网络情况良好阶段,该因子增长速率大,以充分利用网络资源;而在逼近网络拥塞阶段,该因子以较小的速率增长,以避免过激的拥塞丢包。数学分析说明了新算法的可行性,并通过NS仿真对其吞吐量、公平性、友好性进行评估。仿真结果表明该改进的TCP拥塞避免算法的有效性。     

A fuzzy reasoning and fuzzy-analytical hierarchy process based approach to the process of railway risk information: A railway risk management system

Risk management is becoming increasingly important for railway companies in order to safeguard their passengers and employees while improving safety and reducing maintenance costs. However, in many circumstances, the application of probabilistic risk analysis tools may not give satisfactory results because the risk data are incomplete or there is a high level of uncertainty involved in the risk data. This article presents the development of a risk management system for railway risk analysis using fuzzy reasoning approach and fuzzy analytical hierarchy decision making process. In the system, fuzzy reasoning approach (FRA) is employed to estimate the risk level of each hazardous event in terms of failure frequency, consequence severity and consequence probability. This allows imprecision or approximate information in the risk analysis process. Fuzzy analytical hierarchy process (fuzzy-AHP) technique is then incorporated into the risk model to use its advantage in determining the relative importance of the risk contributions so that the risk assessment can be progressed from hazardous event level to hazard group level and finally to railway system level. This risk assessment system can evaluate both qualitative and quantitative risk data and information associated with a railway system effectively and efficiently, which will provide railway risk analysts, managers and engineers with a method and tool to improve their safety management of railway systems and set safety standards. A case study on risk assessment of shunting at Hammersmith depot is used to illustrate the application of the proposed risk assessment system.     

基于T-H方程的编队卫星碰撞概率与规避策略研究

基于T-H方程,对椭圆轨道下编队卫星碰撞预测以及规避机动进行了研究。通过递推编队卫星的初始状态协方差矩阵,将碰撞概率密度在危险域内积分获得编队卫星的碰撞概率。当碰撞概率大于安全阈值时,采用瞬时校正速度的控制策略对卫星施加最小脉冲速度修正量,在所预测的碰撞点沿碰撞概率梯度产生偏移,到达安全等高线上,从而降低碰撞概率。仿真结果表明,该预测方法有效,规避策略可行。     

基于风险管理的软件开发过程模型

所谓软件开发过程中的风险,指的是在软件的开发过程中,可能会遇到的关于进度和预算方面的问题,或者是这些问题对软件开发的影响。如果软件开发过程中的风险变为现实,就会增加项目成本、影响项目进度、打乱软件开发计划,甚至最终影响软件项目的实现。风险管理对于软件开发来讲,就是为了尽可能的降低风险发生概率。如果对软件开发中的风险管理...     

基于人工势场法的多智能体编队避障方法

编队避障问题是多智能体编队研究的关键问题之一。针对动态环境中多智能体编队避障问题,提出了一种基于人工势场法（APF）与布谷鸟搜索算法（CS）相结合的编队避障方法。首先,在动态队形变换策略的异构模式下,利用APF为多智能体编队中每个智能体规划避障;然后,针对APF在引力增量系数和斥力增量系数设置的局限性,利用CS中的莱维飞行机制思想,来随机搜索得到适应环境的增量系数。Matlab仿真实验结果表明,所提方法能够有效地解决复杂环境下多智能体编队避障问题,使用效率函数对实验数据进行评价及分析,验证了所优化方法的合理性和有效性。     

Robotics in Education

Collision avoidance is essential for safe robot manipulation. Especially with humans around, robots should work only when safety can be robustly guaranteed. In this paper, we propose using virtual impedance control for reactive, smooth, and consistent collision avoidance that interferes minimally with the original task. The virtual impedance control operates in the risk space, a vector space describing the possibilities of all forthcoming collisions, and is designed to elude all risks in a consistent response in order to create assuring human-robot interaction experiences. The proposed scheme intrinsically handles kinematic singularity and the activation of avoidance using a boundary layer defined on the spectrum of Jacobian. In cooperation with the original controller, the proposed avoidance scheme provides a proof of convergence if the original controller is stable with and without projection. In simulations and experiments, we verified the characteristics of the proposed control scheme and integrated the system with Microsoft Kinect to monitor the workspace for real-time collision detection and avoidance. The results show that the proposed approach is suitable for robot operation with humans nearby.     

基于多智能体深度强化学习的船舶协同避碰策略

船舶避碰是智能航行中首要解决的问题,多船会遇局面下,只有相互协作,共同规划避碰策略,才能有效降低碰撞风险.为使船舶智能避碰策略具有协同性、安全性和实用性,提出一种基于多智能体深度强化学习的船舶协同避碰决策方法.首先,研究船舶会遇局面辨识方法,设计满足《国际海上避碰规则》的多船避碰策略.其次,研究多船舶智能体合作方式,构建多船舶智能体协同避碰决策模型:利用注意力推理方法提取有助于避碰决策的关键数据;设计记忆驱动的经验学习方法,有效积累交互经验;引入噪音网络和多头注意力机制,增强船舶智能体决策探索能力.最后,分别在实验地图与真实海图上,对多船会遇场景进行仿真实验.结果表明,在协同性和安全性方面,相较于多个对比方法,所提出的避碰策略均能获得具有竞争力的结果,且满足实用性要求,从而为提高船舶智能航行水平和保障航行安全提供一种新的解决方案.     

自主车辆安全系数估计与T形路口避碰规划

针对自主车辆T形路口协作问题,通过测量车辆速度和预碰点距离,提出安全系数估计方法,结合人工势场基本思想,实现车辆路口避碰,提高路口协作效率.首先以计算得到的安全系数为依据,评价驶入T形路口两辆自主车各自的安全程度,并利用人工势场产生的推拉作用估计协作自主车辆的期望控制力和速度.然后将估计的期望车速与反馈的实际车速形成偏差,利用增量型数字PI控制器实现自主车纵向车速的准确控制.最后以一定的策略完成两辆自主车的并线协作.仿真结果验证了基于安全系数估计的自主车辆T形路口协作避碰的可行性与有效性.