Improved Behaviour Control on Laser Cruise of Autonomous Mobile Robot

The software of behaviour-based algorithm~ was parted to several functional modules which represented different behaviours with different priorities. A basic algorithm with S-type arbiter and an improved algorithm with I-type arbiter were compared. The improved algorithm can reduce judging time and avoid some mistakes of the basic one. In mapping obstacles, the robot adjusted the spread angle according to different distances to obstacles in scaled vector field histogram （SVFH） algorithm, and then the robot turned more sharply in near obstacles than in far obstacles, which made the robot move more safely and smoothly in a cluttered room.

Chaotic behaviours and control of chaos in the p-Ge photoconductor

The chaotic behaviours in the p-Ge photoconductor system are studied by changing the photo-excitation coefficient and the routes and parameter conditions are given for chaos generation in this system. A scheme for controlling chaos in the p-Ge photoconductor is presented by adding an ac bias current. Numerical simulations show that this scheme can be effectively used to control chaotic states into stable period states for this system. Moreover, the different period states with diifferent period numbers can be obtained by appropriately adjusting the amplitude, frequency, and initial phase of the additional ac current.

ON THE ASYMPTOTICAL BEHAVIOUR OF SOLUTIONS OF A CLASS OF NONLINEAR CONTROL SYSTEMS

In this paper, the asymptotical behaviour solutions of a class of nonlinear control systems are studied. By establishing infinite integrals along solutions of the system and drawing support from a LaSalle's invariance principle of integral form, criteria of dichotomy and global asymptotical behaviour of solutions are obtained. This work is an improvement and further extension of research methods and results of A. S. Aisagaliev.

Relationship between Level of Knowledge on Anger Control and Occurrence of Real Assaultive Behaviour in Patients (20 - 45 Years) Admitted at a National Referral Psychiatric Hospital in Zimbabwe

Background: Aggressive tendencies from psychiatric inpatients are increasingly becoming problematic at a national referral psychiatric hospital in Zimbabwe. No research has been done in this context to determine the dynamics around this disturbing phenomenon. Objectives: To determine the level of knowledge on anger control, to determine the occurrence of real assaultive behaviour and to examine the relationship between level of knowledge on anger control and occurrence of real assaultive behaviour in patients aged 20 - 45 years admitted at a national referral psychiatric hospital in Zimbabwe. Method: A descriptive correlational design was used. Seventy-six respondents aged between 20 and 45 years were selected using simple random sampling. A structured interview was used to collect data. The occurrence of real assaultive behaviour was adapted from the Staff Observation and Aggression Scale completed by observing patients during the assaultive behaviour occurrence. Patient observation was done by the psychiatric trained nurses who were specifically trained for this study to fill the part of the data collection instrument that needed observation. Data were analysed using descriptive statistics, Pearson Correlation Coefficient test and simple regression analysis. Results: Results showed a Pearson coefficient test of (r = -3.47, p Conclusions: Results call for collaboration of mental health practitioners to empower patients with anger control skills.

铝合金板冲压摩擦试验机开发与试验

针对铝合金板冲压成形对摩擦测试的需求,确定考虑加热条件下铝合金板材冲压摩擦伺服压力摩擦测试平台的总体设计方案,开发适用于铝合金板材成形的小载荷高精度多功能摩擦试验机系统。该系统由运动组件、加热系统及控制系统组成。运动组件实现上模具和夹头的运动支撑;加热系统实现模具与试件单独加热;在伺服控制模式下,结合外部力传感器和光栅尺,实现试件压力和模具间隙高精度高稳定性控制。实际应用检验该试验机对不同因素的区分度和重复性,并设计正交试验,探索不同因素对铝合金板材摩擦的影响。结果表明:试验机性能稳定,重复性好;影响摩擦系数因素的重要次序为:模具温度、压力、速度、润滑剂;温度越低,压力越大,速度越快,摩擦系数越小;同一种类型的润滑剂对摩擦系数的影响较小。随着压力的增大,摩擦系数减少的趋势越来越小,逐渐趋于平稳。

不同控制模式下316L不锈钢的高温疲劳变形行为及寿命预测

在550℃下对核电用316L不锈钢进行应变控制(应变幅在0.3%~1.2%)、应力控制(应力幅在230~300 MPa)低周疲劳试验和应变控制蠕变疲劳试验(3种波形,拉伸保载60,180,600 s,压缩保载60,180 s,拉压对称保载180 s),通过疲劳寿命、循环响应特征和应力-应变滞回曲线分析了不同控制模式下试验钢的疲劳变形行为;构建疲劳寿命预测模型,评估了Manson-Coffin-Basquin模型、SWT模型和能量法模型对不同控制模式下试验钢疲劳寿命的预测能力。结果表明:在不同控制模式的疲劳循环载荷下,316L不锈钢的循环应力响应均包括循环硬化、循环软化和失效断裂3个阶段;在低周疲劳试验中,疲劳寿命随应变幅或应力幅的增大而缩短;在蠕变疲劳试验中,疲劳寿命随拉伸保载时间的延长而缩短,随压缩保载时间的延长而增大,这与动态应变时效和蠕变对疲劳损伤的综合作用有关;在相同保载时间下,压缩保载下的疲劳寿命比拉伸保载下的短,这与不同加载方向引起的氧化层致裂机制有关。能量法模型对316L不锈钢在不同控制模式下的疲劳寿命预测精度最高,预测精度在1.5倍误差带以内,Manson-Coffin-Basquin模型的预测精度最低。

不同养护条件下黏土热力学性质试验

温度对土的物理力学特性有较大影响,对黏土开展了不同养护条件下的温控三轴试验,研究了黏土在不同温度、不同时间下的热力学特性。试验结果表明:黏土具有热固结性质,随着温度的增加,黏土的固结速度加快,试验固结时间呈下降趋势;在临界温度以下,土体应力-应变曲线呈现软化特性,为脆性破坏;在临界温度以上,土体应力-应变曲线呈现硬化特性,为塑性破坏;黏土具有类似于混凝土“养护温度”的性质,即同一温度作用下,养护时间越长,主应力差越大;黏聚力在临界温度范围以内,随温度升高而降低,而在临界温度以上,随温度升高而增大;内摩擦角在临界温度范围以内,基本不受温度变化的影响,而在临界温度以上,内摩擦角随温度增加而增大;黏土强度随养护时间的增长过程分为快速增长阶段、较快增长阶段、缓慢增长阶段,其最佳养护时间为快速增长阶段和较快增长阶段。

多学科协作护理在高血压患者中的应用价值

目的 分析多学科协作护理在高血压患者中的应用价值。方法 回顾性纳入2020年5月至2023年6月我院收治的高血压患者100例,依据护理方案不同将入选者分成对照组(35例)和观察组(36例)。对照组接受常规护理,观察组接受多学科协作护理,评价组间遵医行为、血压控制情况、心理状态、生活质量。结果 干预后,观察组正确用药、自我观察、康复运动、饮食调整等遵医行为以及口服药知晓率均高于对照组(P<0.05);观察组收缩压和舒张压均低于对照组(P<0.05);观察组焦虑自评量表(SAS)和抑郁自评量表(SDS)评分低于对照组(P<0.05);观察组生活质量各维度得分均高于对照组(P<0.05)。结论 为高血压患者实施多学科协作护理可改善患者的遵医行为、生活质量及心理状态,同时对患者血压水平的控制也具积极作用。

Control of chaotic oscillations of a satellite

Analytical conditions and practical methods of their realization are proposed to solve a problem of a command signal tracking for a nonlinear disturbed system. Nonlinear disturbed plants consisting of linear dynamic block and nonlinear block in feedback are considered. Nonlinear part of the plant and disturbance are unknown and bounded. The paper illustrates a possibility of applications of proposed algorithms to control libration angle of satellite.

矿山“生产冒进行为”的演化博弈分析

“生产冒进行为”是矿山生产过程中对安全生产状态影响较大的不安全行为。为研究其产生的原因,采取相应的控制策略,采用演化博弈理论构建了工人和安全监管者演化博弈模型,并运用系统动力学方法分析了博弈过程。结果表明:(1)工人安全行为和安全监管者监管行为的成本与利益,是影响矿山“生产冒进行为”产生的重要原因;(2)矿山监管力度影响着工人不安全行为产生概率,在一定范围内,矿山监管力度与工人行为的安全概率呈正相关;(3)提高安全监管者对不稳定状态工人的经济惩罚,增大不稳定状态工人承担的风险成本,能够在短期内改善企业的安全生产状况;(4)工人处于行为安全状态的收益对工人行为安全和安全监管者监管行为的影响最大,企业可依据动态博弈演化过程和模型参数的影响程度,制定相应的安全管控策略。

ROBUST CONTROL WITH COVARIANCE CONSTRAINT FOR UNCERTAIN SAMPLED-DATA FEEDBACK CONTROL SYSTEMS

The problem of robust controller design with covariance constraint for uncertain sampled data feedback control systems was considered in this paper. The goal of this problem is to design controllers such that the closed loop system meets the prespecified covariance constraint. This problem can be reduced to a controller design problem for an equivalent uncertain discrete time system. Sufficient conditions were given for the existence of the desired controllers. The analytical expression of the set of desired controllers was also presented. An illustrative example was given to show the applicability of the proposed design procedure.

DEADBEAT COVARIANCE CONTROLLER DESIGN FOR SAMPLED-DATA SYSTEMS

The problem of deadbeat covariance controller design for sampled data feedback systems is considered. The purpose of considering this problem is to design linear discrete controllers such that the state covariance of the closed loop system achieves its steady state value which is equal to a prespecified positive definite matrix during finite beats. This problem is reduced to the similar one for equivalent discrete time systems by taking intersample behaviour into account. Both the existence conditions and the explicit expression of the desired controllers are given.

Dynamic models of pest propagation and pest control

This paper proposes a pest propagation model to investigate the evolution behaviours of pest aggregates. A pest aggregate grows by self-monomer birth, and it may fragment into two smaller ones. The kinetic evolution behaviours of pest aggregates are investigated by the rate equation approach based on the mean-field theory. For a system with a self-birth rate kernel I（k） = Ik and a fragmentation rate kernel L（i,j） = L, we find that the total number MoA（t） and the total mass of the pest aggregates MA （t） both increase exponentially with time if L ≠ 0. Furthermore, we introduce two catalysis-driven monomer death mechanisms for the former pest propagation model to study the evolution behaviours of pest aggregates under pesticide and natural enemy controlled pest propagation. In the pesticide controlled model with a catalyzed monomer death rate kernel J1 （k） ---- J1 k, it is found that only when I 〈 J1 B0 （B0 is the concentration of catalyst aggregates） can the pests be killed off. Otherwise, the pest aggregates can survive. In the model of pest control with a natural enemy, a pest aggregate loses one of its individuals and the number of natural enemies increases by one. For this system, we find that no matter how many natural enemies there are at the beginning, pests will be eliminated by them eventually.

Design of Poiseuille Flow Controllers Using the Method of Inequalities

This paper investigates the use of the method of inequalities （MoI） to design output-feedback compensators for the problem of the control of instabilities in a laminar plane Poiseuille flow. In common with many flows, the dynamics of streamwise vortices in plane Poiseuille flow are very non-normal. Consequently, small perturbations grow rapidly with a large transient that may trigger nonlinearities and lead to turbulence even though such perturbations would, in a linear flow model, eventually decay. Such a system can be described as a conditionally linear system. The sensitivity is measured using the maximum transient energy growth, which is widely used in the fluid dynamics community. The paper considers two approaches. In the first approach, the MoI is used to design low-order proportional and proportional-integral （PI） controllers. In the second one, the MoI is combined with McFarlane and Glover＇s H∞ loop-shaping design procedure in a mixed-optimization approach.

Joints in unsaturated rocks:Thermo-hydro-mechanical formulation and constitutive behaviour

A formulation for the coupled analysis of thermo-hydro-mechanical （THM） problems in joints is first presented. The work involves the establishment of equilibrium and mass and energy balance equations. Balance equations were formulated taking into account two phases： water and air. The joint element developed was implemented in a general purpose finite element computer code for THM analysis of porous media （Code_Bright）. The program was then used to study a number of cases ranging from laboratory tests to large scale in situ tests. A numerical simulation of coupled hydraulic shear tests of rough granite joints is first presented. The tests as well as the model show the coupling between permeability and the deformation of thejoints. The experimental investigation was focused on the effects of suction on the mechanical behaviour of rock joints. Laboratory tests were performed in a direct shear cell equipped with suction control. Suction was imposed using a vapour forced convection circuit connected to the cell and controlled by an air pump. Artificial joints of Lilla claystone were prepared.Joint roughness of varying intensity was created by carving the surfaces in contact in such a manner that rock ridges of different tip angles were formed. These angles ranged from 0° （smooth joint） to 45° （very rough joint profile）. The geometric profiles of the two surfaces in contact were initially positioned in a ＂matching＂ situation. Several tests were performed for different values of suctions （200, 100, and 20 MPa） and for different values of vertical stresses （30, 60, and 150 kPa）. A constitutive model including the effects of suction and joint roughness is proposed to simulate the unsaturated behaviour of rock joints. The new constitutive law was incorporated in the code and experimental results were numerically simulated.

-天然气 煤炭交叉开采事故致因机理研究

针对我国沉积盆地中煤炭和天然气普遍存在矿权交叉现象,煤炭和天然气同时开采、相互影响严重,两者的协同开采问题以及事故隐患亟待解决。考虑天然气与煤炭开采在相同时空范围内,相互制约影响环节较多,本文基于能量异常释放模型和STAMP等事故致因理论提出了能量控-制失效模型,以解释信息转移循环特征;基于对天然气和煤炭的开采工艺过程,建立了气煤交叉开采活动的能源单元、屏障单元、承灾体之间的交互关系,分析了能量转移及安全屏障相互作用的特征,研判了9种意外释放情景,提出了气-煤交叉开采关键控制行为识别和确保关键控制行为有效-的技术措施。研究结果对预防气煤交叉开采事故提供参考。

吸毒服刑人员攻击性行为与父母教养方式、父母心理控制的关系研究

为探讨吸毒服刑人员攻击性行为与父母教养方式、父母心理控制之间关系,使用父母教养方式问卷(PBI)、父母心理控卷(PCS-YSR)、Buss-Perry攻击性量表(BPAQ)对安徽省合肥市滨湖戒毒所内300名吸毒服刑人员进行问卷调查。人口变量学统计结果显示:66.7%的被试者毒龄超过5年,67.8%的被试者第一次接触的毒品为冰毒,91%的被试者未接受过高等教育,92%的被试者第一次吸食的毒品从朋友处获得。问卷、控卷与量表数据统计分析表明:父母教养方式中父亲的冷漠因子、过度保护因子以及母亲的过度保护因子与被试者的攻击性行为呈显著正相关;父母心理控制与父母教养方式中父母的冷漠因子、过度保护因子呈显著正相关,与父母的自主性因子呈显著负相关;父母心理控制与被试攻击性行为呈显著正相关。而母亲的过度保护、自主性因子和父母心理控制对被试者的攻击性行为具有正向预测作用。

地区污名对旅行者负责任环境行为的影响研究

重大公共卫生事件往往会给旅游业的可持续发展带来冲击,甚至使得来自疫区的旅行者遭受到社会强加的地区污名。文章以资源保存理论为理论基础,以认知评价理论为整体逻辑,以新冠疫情暴发初期的湖北籍旅行者为研究对象,探讨了旅行者的地区污名对其自我概念清晰度、负面情绪以及负责任环境行为的影响,并进一步分析了自我证明动机对该链式中介模型的调节作用。通过问卷调研239名的旅行者,文章利用Mplus和SPSS软件进行了结构方程分析、Bootstrap分析以及潜调节结构模型分析,实证检验发现:(1)地区污名对负责任环境行为存在负向影响;(2)自我概念清晰度与负面情绪分别在地区污名对负责任环境行为的影响中发挥中介作用;(3)自我概念清晰度与负面情绪在地区污名对负责任环境行为的影响中起链式中介作用;(4)自我证明动机通过减弱地区污名对自我概念清晰度的负向影响进而对链式中介路径起调节作用。文章在借鉴资源保存理论的基础上,结合重大公共卫生事件中的地区污名化现象,阐释了地区污名化效应的内在逻辑及其干预措施,以期为重大卫生事件中如何优化旅行者体验和促进旅游业可持续发展提供理论依据。

模型未知LTI系统的数据驱动预测控制

针对含有随机噪声的模型未知线性时不变(LTI,linear time invariant)系统模型建立过程复杂且控制律难以得到的问题,提出一种基于数据驱动的预测控制方法;基于系统行为学理论和平衡子系统辨识方法,仅利用测量得到的系统数据构建被控系统的非参数模型,将其和预测控制理论相结合设计出基于数据驱动的预测控制器,对于系统测量数据中存在的有界加性高斯噪声,通过引入数据的松弛变量和L2正则项来降低噪声扰动的影响,采用滚动时域优化策略计算最优控制序列并将其作用于被控系统,实现了系统对设定值的轨迹跟踪;将所提控制策略应用于四容水箱系统,仿真结果表明所提方法能实现四容水箱系统的液位跟踪控制,且与同样基于数据驱动的子空间预测控制方案相比,所提方法具有更好的动态性能,且该策略在抗噪声扰动方面有明显优势,具有更强的鲁棒性。

无线传感器网络中一种基于行为可信的访问控制机制

访问控制是无线传感器网络的一种重要应用,已有研究工作大多是通过相邻传感器之间的密钥交换来实现。从传感器行为的空间相关性和时间相关性入手,提出了一种基于相似度的以局部检测为主的分布式传感器行为可信的访问控制机制。该机制通过检验传感器本地采样值构成的时空相似度与传感器行为随机过程统计特征的符合程度来实现行为信任的访问控制。模拟仿真试验表明,该机制可以减少传感器之间的数据交换,当网络中10%的传感器存在不安全行为时,该模型可以检测到95%的不可信传感器。