Fractional Modeling and Analysis of Coupled MR Damping System

The coupled magnetorheological (MR) damping system addressed in this paper contains rubber spring and magnetorheological damper. The device inherits the damping merits of both the rubber spring and the magnetorheological damper. Here a fractional-order constitutive equation is introduced to study the viscoelasticity of the combined damper. An introduction to the definitions of fractional calculus, and the transfer function representation of a fractional-order system are given. The fractional-order system model of a magnetorheological vibration platform is set up using fractional calculus, and the function of displacement is presented. It is indicated that the fractional-order constitutive equation and the transfer function are feasible and effective means for investigating of magnetorheological vibration device. © 2014 Chinese Association of Automation.

Effects of Spherical Aggregates Addition on Properties of Al2O3-SiO2 System Castables

Compared with traditional aggregates,spherical aggregates with high flowability,easy control of particle size distribution and favor of dense packing and so on,are expected to replace traditional aggregates as important raw materials for future high performance refractories. Therefore,investigation of effects of spherical aggregates addition on properties of refractories becomes very meaningful. Using A70 mullite traditional aggregates and A70 mullite spherical aggregates, bauxite homogenization powder,microsilica,and calcium aluminate cement as raw materials,different AlO-SiOsystem low cement castables were prepared by replacing conventional aggregates with spherical aggregates. The effect of spherical aggregates addition on workability and mechanical properties of castables after heated at different temperatures was researched,and microstructure of the specimen was analyzed by SEM. Compared with traditional irregularly shaped aggregates,spherical aggregates endow castables with better flowability and easy pump ability. By introduction of spherical aggregates into the castables,flowability and pumpability are significantly improved,and water addition and ball completely sunk time are reduced. The introduction of spherical aggregates is favorable to density and cold crushing strength of castables,but unfavorable to CMOR. The effect of spherical aggregates addition on HMOR at1 400 ℃ can be negligible. Microstructure analysis showsthat the boundary bonding between spherical aggregates and matrix is strong,similar to the traditional aggregates.

ARTIFICIAL NEURAL NETWORKS BASED GEARS MATERIAL SELECTION HYBRID INTELLIGENT SYSTEM

An artificial neural networks(ANNs) based gear material selection hybrid intelligent system is established by analyzing the individual advantages and weakness of expert system (ES) and ANNs and the applications in material select of them. The system mainly consists of tow parts: ES and ANNs. By being trained with much data samples, the back propagation (BP) ANN gets the knowledge of gear materials selection, and is able to inference according to user input. The system realizes the complementing of ANNs and ES. Using this system, engineers without materials selection experience can conveniently deal with gear materials selection.

Time evolution of information entropy for a stochastic system with double singularities driven by quasimonochromatic noise

This paper deals with the time evolution of information entropy for a stochastic system with double singularities driven by quasimonochromatic noise. The dimension of the Fokker Planck equation is reduced by the linear transfor- mation. The exact expression of the time dependence of information entropy is obtained based on the definition of Shannon＇s information entropy. The relationships between the properties of dissipative parameters, system singularity strength parameter, quasimonochromatic noise, and their effects on information entropy are discussed.

Application of Internet of Things in Urban Waterlogging Prevention Management System

This paper aims to realize the extensive application of Internet of things technology in urban waterlogging prevention management system, and has analyzed the security requirement and security architecture of Internet of things technology, and discussed the demand of urban waterlogging prevention management system in combination with the key technology of Internet of things technology, to do the overall design and functional design well during designing of urban waterlogging prevention management system. Finally, the application process of the Internet of things technology in Chongqing waterlogging prevention management system is summarized. The application result shows that the flood control and drainage function of Chongqing is gradually improved with smooth drainage facilities;the inspection and maintenance management is gradually standardized;operation monitoring and early warning management is fully strengthened. There is visual management for emergency command and dispatch, and at the same time, the drainage pipe network assessment management can be conducted correctly.

Bayesian estimation for nonlinear stochastic hybrid systems with state dependent transitions

The Bayesian approach is considered as the most general formulation of the state estimation for dynamic systems. However, most of the existing Bayesian estimators of stochastic hybrid systems only focus on the Markov jump system, few liter- ature is related to the estimation problem of nonlinear stochastic hybrid systems with state dependent transitions. According to this problem, a new methodology which relaxes quite a restrictive as- sumption that the mode transition process must satisfy Markov properties is proposed. In this method, a general approach is presented to model the state dependent transitions, the state and output spaces are discreted into cell space which handles the nonlinearities and computationally intensive problem offline. Then maximum a posterior estimation is obtained by using the Bayesian theory. The efficacy of the estimator is illustrated by a simulated example .

Dynamic characteristics of the coupled system of footbridge and human

The influence of human body on dynamic characteristics of footbridge was analyzed. A re- alistic footbridge was measured during a mass event. A simulation experiment system including a simple beam as object and a shaker as back ground excitation was built. The acceleration responses of beam were measured when person in static and active stated stood on the beam. The dynamic pa- rameters of the structure were identified by the time-domain approach and verified by theoretical and laboratory tests. The results showed that for the human-structure coupled system, nature frequency of the structure decreased and damping increased. Moreover, the increase of damping with passive person was bigger than that with active person.

Transient responses of transparency in a far-off resonant atomic system

Transient coherent oscillations in a closed A system under far-off resonant Raman fields were investigated theoreti- cally. It has been found that the coherent superposition of the ground states can be formed due to the absorption even for initial maximal mixed ground states. The absorption oscillates with a period depending on the two-photon detuning when the system is initially in a transparent state and the two-photon Raman detuning is suddenly changed. The amplitude of the absorption decays with the decay rate of the ground states, which is different from the case when the lasers are applied resonantly. These transient coherent oscillations can be used to measure the relaxation rate of the ground states.

Lyapunov-type inequalities for fractional differential systems with more than three

This paper presents Lyapunov-type inequalities for fractional differential systems with more than three monomials by using the Gronwall-Inequality and the Greens function.The results of this paper extend the research methods of similar problems and generalize some early conclusions on this topic.In addition,with the help of the results,we can analyze the solution of differential systems.

Bioenergy Crops as a Promising Alternative to Fossil Fuels in Louisiana: A Geographic Information System (GIS) Perspective

Rising greenhouse gas emissions are causing climate change, and the world’s focus has shifted to the need to reduce our reliance on fossil fuels. There has been a rise in the published literature on the utilization of crops for bioenergy production in Louisiana. However, very few scholarly documents have used Geographic Information Systems (GIS) to map the distribution of potential bioenergy crops in Louisiana. This study seeks to fill the void by evaluating the potential of bioenergy crops in Louisiana for energy production using GIS. Given this objective, the agricultural census data for 1999, 2009, 2019, and 2020 obtained from the U.S. Department of Agriculture were used in the analysis. The quantities of various crops produced in the state were loaded into an attribute table and joined to a shapefile using ArcGIS software. The symbology tool’s graduated option was used to create five maps representing each of the bioenergy crops in Louisiana. The findings of the GIS analysis show that some of the parishes, such as Franklin produced the most bushels of corn (13,795,416), Iberia produced the most tons of sugarcane (1,697,980), East Carroll produced the most bushels of soybean (8,237,991), Tensas harvested the most bales of cotton (80,898) and Avoyelles produced the most bushels of sorghum (630,694). The abundance and availability of crops as raw materials for energy production will translate into lower prices in terms of energy use, making bioenergy crops a promising alternative to fossil fuels. In addition, gasoline price data from 1993-2022 was obtained from U.S. Energy Information Administration. A regression model for the average annual gasoline price over the years was constructed. The results show that the average annual gasoline price variation with respect to years is statistically significant (p 0.05). This suggests that gasoline prices will generally rise despite a price drop over the years. The paper concludes by outlining policy recommendations in the form of assessing the availability and viability of other crop types, such as wheat, oats, and rice, for energy production in the state.

“在地国际化”视域下高等职业教育中外合作办学质量认证体系研究

“在地国际化”是突破高校师生跨境流动的传统观念,在本土创设国际化学习环境、教学资源和育人机制的教育模式。中外合作办学是高等职业教育“在地国际化”的载体与表现形式。在“在地国际化”视域下,中外合作办学存在理念更迭滞缓、认证系统与评价体系未协同、缺乏国际通行认证指标体系等问题,高等职业教育中外合作办学质量认证体系的建构将满足面向全球,培养国际化人才质量保障需求。依据“输入-环境-输出”理论模型,高等职业教育中外合作办学“在地”发展质量认证体系的构建与应用旨在凸显夯实高等职业教育国际化人才培养质量观、实现国际化高技能人才在地培养的实质等效和增强“在地”培养国际化技术技能型人才实力的应用价值。

离散时间的完全服务并行优化轮询排队系统特性分析

轮询是一种依次有序服务的系统资源动态调度机制.针对服务器在站点间查询、服务和转移过程中的流水线作业方式导致了系统整体服务效率较低的问题,本文提出了完全服务的并行优化轮询系统.首先,构建了系统的单服务器多队列排队模型和相应的系统状态方程,并精确解析出系统特性参数的完整数学解析表达式.此外,还提出了一种系统状态稳定性的判定方法,对不同负载状态下的系统稳定性进行了定量分析.计算机仿真的统计分析结果与理论计算值相一致.最后,系统性能分析表明,在保持周期性、无冲突服务的基础上,系统的队长、时延特性和稳定状态下负载能力均得到了较大的提高.

文旅深度融合发展赋能中国式现代化:逻辑、挑战与提升路径

文旅深度融合发展是实现文化和旅游产业现代化的根本途径,也是中国式现代化的重要组成部分。中国式现代化与文旅深度融合发展存在紧密的内在逻辑关系,前者引领后者的价值取向,后者是前者实现的重要路径。当前,在文旅深度融合发展赋能中国式现代化进程中,面临着专业人才匮乏、区域及城乡差距显著、创新驱动力不足、绿色发展理念欠缺、西方文化渗透形势严峻、法治监管缺位等现实挑战。因此,亟须健全文化和旅游深度融合发展体制机制,构建文旅人才支撑体系、强化文旅区域协同与城乡联动机制、推动形成文旅深度融合发展创新机制、完善文旅产业绿色发展机制、构建国际文旅交流合作机制、完善文旅法治体系等,为推进中国式现代化贡献文旅力量。

基于职业可持续发展的大学生素质评价:理论、模型与指标体系

基于评价模式改革引导高素质大学生培养已经成为国家关注的重点,已有大学生评价体系不能适应促进学生终身职业发展的需要,必须建立起以职业发展素质为核心的素质评价体系。文章对国内外职业可持续发展能力和素质评价体系相关研究进行综述,借鉴分析职业素质三角模型理论,新增动力要素和适应要素两个维度,重新构建职业发展素质五维模型,并通过文献分析选用11个关键素质作为二级指标,最终构成以培养大学生职业可持续发展能力为导向的素质评价指标体系。

档案目录数据汇集制度运行模式研究——基于《中华人民共和国档案法实施条例》第二十五条

《中华人民共和国档案法实施条例》的公布,为新时代档案工作的实践提供了具体的实施细则和新的法规遵循。论文基于《中华人民共和国档案法实施条例》第二十五条,从适应档案事业发展阶段的需求、规范国有档案管理、档案信息资源开发利用和档案目录数据安全四个方面探讨档案目录数据汇集制度产生的必要性,并以PDCA模型为基础构建档案目录数据汇集制度的运行模式,以期为档案目录数据汇集制度的建立和实施提供参考。

电网数字孪生分析模型建模及应用

为支撑新一代调度技术支持系统全局分析计算业务融合,提出一种基于数据孪生的电网分析模型构建方法。基于实际电网设备的物理和逻辑关系,构建出标准化、对象化的完整电网分析模型,并接入实时量测,使其成为真实空间物理电网的数字孪生。在传统通用数据库与专业计算应用间构建出更贴近电网分析计算业务的数据中台,为在线分析计算应用提供统一数据服务。通过在新一代调度支持系统华中试点工程的建设成效,展示了基于数字孪生模型的分析计算应用的性能提高效果。

经皮微创桥接组合式系统治疗锁骨干骨折的疗效分析

目的 比较经皮微创桥接组合式系统(OBS)与切开复位钢板内固定治疗锁骨干骨折的疗效。方法 回顾性分析2016年8月至2020年12月中国科学技术大学附属第一医院采用经皮微创OBS技术或切开复位钢板内固定治疗50例锁骨干骨折病人的资料,其中OBS组23例,钢板组27例。比较两组病人的切口总长度、术中出血量、骨折愈合时间、术后肩关节ConstantMurley评分以及术后并发症发生情况等。结果 OBS组病人术中手术时间[(71.74±6.23)min]较钢板组病人[(57.81±6.73)min]长,但切口总长度[(6.09±0.67)cm]、术中出血量[(20.52±4.31)mL]及骨折愈合时间[(10.57±0.51)周]优于钢板组病人[(9.41±0.63)cm、(48.67±6.93)mL、(12.42±0.50)周],均差异有统计学意义(P<0.05)。OBS组病人术后切口周围感觉异常发生率[1例(4.3%)]较钢板组病人[9例(33.3%)]低(P<0.05)。而两组病人术后切口感染、切口瘢痕增生、骨折不愈合、内固定失效及术后3、6、9个月随访时Constant-Murley评分比较均差异无统计学意义(P>0.05)。结论 OBS作为新型内固定系统在治疗锁骨干骨折时和钢板疗效相当,均能获得较好的临床功能结果,且具有切口小、出血量少、切口周围感觉异常发生率低等优势。

数据与模型双核驱动的城市轨道交通自动售检票智能运维系统架构设计与实现

[目的]城市轨道交通传统AFC(自动售检票)系统存在维修速度慢、维修方法过时、维修计划不合理和维修成本高等问题。需要采用数字化与智能化主动监测维护方法,基于数据与模型双核驱动搭建城市轨道交通AFC智能运维系统,将周期性的计划修转变为状态修和预知修,进而提高运维效率,降低运维成本。[方法]介绍了城市轨道交通AFC智能运维系统的架构及主要功能。先通过多传感器融合收集终端设备的数据,并通过上传到大数据平台进行处理,再利用深度学习算法与天牛须搜索优化算法对收集的数据进行数据分析,并优化模型,进而识别故障模式和预测潜在的设备故障。此外,该系统还采用了自动化工作流程管理工具来分析运维任务的执行效率,以优化日常维护和紧急响应策略。[结果及结论]该系统在上海轨道交通3号线试点运行中表现出色,能实现智能维护、设备动态履历管理、远程监控、移动终端、无纸化维护等功能,其运行平稳、操作方便、流程顺畅。通过效益分析可知,该系统切实提高了工作维修效率,降低了运营成本。

民用直升机海上搜救遇险人员处置决策支持系统

直升机海上搜救是航空应急救援体系中重要的组成部分,但搜救部门在执行相关任务时通常只能依靠已有经验对险情进行分析并制定处置方案,缺乏理论指导及工具支撑。针对海上应急响应过程中从接收到遇险信息到开始执行海上搜救任务之前的阶段,提出一种海上搜救处置决策支持技术框架,在此基础上,研发民用直升机海上搜救遇险人员处置决策支持系统,并通过海上搜救典型任务进行验证。结果表明:该系统能够通过快速制定处置方案并输出评估结果,为实际执行海上搜救任务的机组人员提供处置决策支持建议,间接提高海上搜救效率。

某半敞开式白酒库消防设计探讨

以四川省某白酒厂半敞开式白酒库的室内消防系统为例,结合规范对白酒库中不同尺寸规格金属白酒储罐的消防设计要求,对泡沫灭火系统、消防冷却水系统类型进行合理的选择。室内消火栓系统采用了喷雾消火栓和辅助泡沫消火栓相结合的方式来处理流散火灾。同时在泡沫灭火系统和消防冷却水系统控制方面增加了手动控制面板,减少因误操作对白酒储存带来的损失,对系统可靠性方面做出了一定的提高。