Design of Underwater Robot Lines Based on a Hybrid Automatic Optimization Strategy

In this paper, a hybrid automatic optimization strategy is proposed for the design of underwater robot lines. Isight is introduced as an integration platform. The construction of this platform is based on the user programming and several commercial software including UG6.0, GAMBIT2.4.6 and FLUENT12.0. An intelligent parameter optimization method, the particle swarm optimization, is incorporated into the platform. To verify the strategy proposed, a simulation is conducted on the underwater robot model 5470, which originates from the DTRC SUBOFF project. With the automatic optimization platform, the minimal resistance is taken as the optimization goal;the wet surface area as the constraint condition; the length of the fore-body, maximum body radius and after-body＇s minimum radius as the design variables. With the CFD calculation, the RANS equations and the standard turbulence model are used for direct numerical simulation. By analyses of the simulation results, it is concluded that the platform is of high efficiency and feasibility. Through the platform, a variety of schemes for the design of the lines are generated and the optimal solution is achieved. The combination of the intelligent optimization algorithm and the numerical simulation ensures a global optimal solution and improves the efficiency of the searching solutions.

Effective Hybrid Teaching-learning-based Optimization Algorithm for Balancing Two-sided Assembly Lines with Multiple Constraints

Due to the NP-hardness of the two-sided assembly line balancing （TALB） problem, multiple constraints existing in real applications are less studied, especially when one task is involved with several constraints. In this paper, an effective hybrid algorithm is proposed to address the TALB problem with multiple constraints （TALB-MC）. Considering the discrete attribute of TALB-MC and the continuous attribute of the standard teaching-learning-based optimization （TLBO） algorithm, the random-keys method is hired in task permutation representation, for the purpose of bridging the gap between them. Subsequently, a special mechanism for handling multiple constraints is developed. In the mechanism, the directions constraint of each task is ensured by the direction check and adjustment. The zoning constraints and the synchronism constraints are satisfied by teasing out the hidden correlations among constraints. The positional constraint is allowed to be violated to some extent in decoding and punished in cost fimction. Finally, with the TLBO seeking for the global optimum, the variable neighborhood search （VNS） is further hybridized to extend the local search space. The experimental results show that the proposed hybrid algorithm outperforms the late acceptance hill-climbing algorithm （LAHC） for TALB-MC in most cases, especially for large-size problems with multiple constraints, and demonstrates well balance between the exploration and the exploitation. This research proposes an effective and efficient algorithm for solving TALB-MC problem by hybridizing the TLBO and VNS.

Generalized CAPP and synthetic evaluation strategy for production line of accuracy welding

This paper presents generalized CAPP （G-CAPP） method which deals with macro process planning for multiobjective in the planning stage of production line of accuracy welding （PLAW） based on the features of accuracy welding production （ AWP ）. G-CAPP offers foundations for prototype design and general equipment sorting, production capacity predication and production analysis by means of simulation and optimization. A synthetic hierarchy evaluation （SHE） model for G-CAPP established according to the planning objective is utilized to estimate the alternate processing plans by using membership function and analytic hierarchy process （AHP） of operational theory. The assembly welding line of hydraulic torque converter （HTC） is as an example of typical A WP to explicate G-CAPP and synthetic evaluating strategy of PLAW. The feasible and rational process configuration strategies of HTC assembly welding line are pointed oat under different planning objective.

Study on The Optimization Strategy of Chinese Coastal Cruise Lines

At present,the cruise industry has become the most rapidly developing industry in the modem tourism industry. The development of Chinese cruise tourism is in the ascendant, and the Chinese cruise lines are also developing and perfecting.Cruise line is an important guarantee for the sustained and healthy development of cruise tourism industry. Based on the theme of China＇s coastal cruise routes, this paper analyzes the layout of the global and Chinese Cruise routes, probes into the development of the cruise and cruise routes in China＇s domestic coastal regions, and on this basis it analyzes the current problems of the development of the domestic coastal cruise lines and puts forward some pertinent countermeasures and suggestions for the problems appearing. The purpose of this study is to provide some help for the development of the cruise industry in China, so as to open up the road for the development of the cruise tourism which is suitable for China＇s national conditions and vigorously promote the development of the cruise industry in China.

A Study on Internal Service Recovery Strategy Using CIT from the First Line Staff's Perspective

Service is a special product. It is intangible and unstored, so service er-rors are not avoided. Once service errors appear, the first line staffs who keep di-rect touch with customers wil play an important role in service recovery. The staffs＇ negative emotions during the recovery service should be recovered by internal ser-vice recovery. In this paper, critical incident technique is applied to analyse the re-covery strategies expected by the first line staff and the internal service recovery strategies such as inspiring, authorization, training and psychology service are put forward. the strategy most expected by the staff is reward.

“一点两线三面”创新实验平台的构建与实践

传统化学实验室功能单一、分布零散、共享性差,导致实验用房和实验设备利用效率低,这种建设模式不利于多学科知识的交叉融合,一定程度上影响学生综合素质的发展。本研究秉承“建优质平台,抓实践育人,树创新理念,育创新人才”的指导思想,在化学实验室资源整合共享、利用率提升、开放式管理以及创新应用型人才培养质量提升等方面积极进行教学改革,经过多年探索,搭建起“以提升学生创新实践能力为着力点”“教学科研两条主线”“教学科研三层面”的创新实验(训)平台,取得了一定成效,将为同类高校的创新实验(训)平台建设提供参考。

Practical Strategies for Urban Rail Transit Loop Planning, Construction, and Operation

Urban rail transit loops are essential in urban rail transit systems and transportation networks.However,precise requirements and reference standards for rail transit loop design have yet to be established.There are certain areas for improvement in planning,construction,and operation.In the planning and design of urban rail transit loops,the scale of the city and the relationship between line operations should be considered to ensure that the line conforms to the city’s operating traffic conditions and can effectively cater to peak passenger flow requirements.This article presents strategies for planning,constructing,and operating urban rail transit loops,laying the foundation for the healthy operation of urban rail transit.

基于单边调制映射函数的LCC-HVDC直流侧阻抗精确建模

阻抗模型是电网换相换流器型高压直流输电系统小信号稳定性分析的重要基础,阻抗模型的准确程度直接影响系统小扰动稳定性分析。该文首先从同步触发原理出发,引入基于单边调制产生的映射函数,该函数蕴含控制及换相信息,可以准确建立换相/非换相期间交直流侧的映射关系;其次,考虑换相动态并通过谐波线性化和傅里叶变换建立完整的直流侧电压和交流侧电流的频域小信号动态模型;再次,考虑控制和换流阀阻尼回路,建立整流侧和逆变侧直流阻抗解析模型;最后,以CIGRE高压直流标准测试模型为例,基于PSCAD/EMTDC平台验证了直流侧阻抗模型的准确性及其用于小扰动稳定性分析的有效性。

关于大食物安全战略背景下我国油料保障底线目标及对策的商榷

树立大食物观和实施大食物安全战略是我国新时代推动食物来源更多元、数量更充足、品质更营养、产业更高效、环境更友好、调控更自主、消费更健康、治理更有力的迫切需要。1978年我国实行改革开放以来,包括油料在内的主要农产品生产、贸易、消费发生了历史性巨变,人民生活水平不断提高,但也存在生产和消费结构失衡导致的慢性疾病增多、环境压力加大、安全风险升高等不容忽视的突出问题,其中油料和食用植物油近十多年处于既自给不足又消费超量的两难局面。基于我国自然资源禀赋和经济社会发展的实际,保障未来油料供给安全必须坚持“一靠油菜、二靠花生、多油并举、健康消费”的发展思路,通过综合施策在十年左右将国产植物油产量稳定提高到2000万吨,以确保居民食用油基本消费需求的安全自主供给底线,并不断改善油料产品质量、提高产业竞争力和促进脂质产品的科学健康消费。

MMC直流侧故障有源限流策略

为了避免直流短路故障威胁到模块化多电平换流器(modular multilevel converter,MMC)型柔性直流电网的安全可靠运行,该文提出了一种适用于半桥型MMC直流侧故障的有源限流策略,限制直流短路电流和桥臂电流的峰值及上升速率。首先,该文阐述了故障期间系统控制策略对故障电流的影响,然后通过反馈桥臂电流分别调整差、共模调制波,进而改变上、下桥臂中子模块的数量及分配,达到快速抑制交、直流侧故障电流的目的。其次,推导了考虑有源限流策略下的故障电流解析式,并分析了该限流策略对控制系统稳定性的影响,为有源阻尼参数选取提供理论依据。最后,在PSCAD/EMTDC中搭建四端柔性直流电网模型,仿真结果表明:有源限流策略不仅能够显著降低直流断路器开断故障电流,且能保证桥臂内器件的安全。

高校武术课程“双线”融合教学策略

通过线上线下“双线”融合教学模式开设相关课程,搭建相关教学模式和体系,形成相关考核制度,已经成为各高校常态化的课程建设路径之一.包括武术课程在内的高校课程“双线”融合教学模式在经历了解释性研究与应用探索阶段之后,目前已进入较为成熟的融合发展阶段.文章基于对部分高校武术课程线上线下教学情况的调研,分析了新时代背景下高校武术课程教学的新策略,探索了“双线”融合创新路径,设计了“双线”融合教学模式,构建了武术课程的线上教学体系,以期实现武术课程教学质量中“量”与“质”的全面提高.

工位数固定的U型拆卸线部分拆卸平衡问题

为提高工位数固定的U型拆卸线拆卸效率,减少有害部件对操作人员的潜在威胁,针对高价值零部件和有害零部件的拆卸需求,本文提出了工位数固定的U型拆卸线部分拆卸平衡问题,建立了以最小化节拍时间、高危工位数目和负载均衡为目标的优化模型,并设计了改进的变邻域搜索算法进行求解.在编码过程中提出一种基于零部件释放位置的选择策略,以减少前继零部件拆卸顺序对编码的影响;提出最小偏差二分法,有效减少解码的迭代次数;提出瓶颈挤压局部搜索策略,用以优化节拍时间和均衡负载指标.通过与其他算法对比,结果表明改进的变邻域搜索算法求解具有优越性,并且可实现对工位数固定的U型拆卸线部分拆卸平衡问题的高效求解.

文化记忆理论视角下三线工业遗产的活化设计策略研究

三线工业遗产是我国社会主义工业化独立自主探索的典型代表,亟需厘清从记忆传承到文化认同的逻辑理路和实践进路。本文以文化记忆理论视角明确了三线工业遗产具备时间、空间、功能三个维度且存在互济、内嵌的逻辑关系,通过建构的方式形成凝聚性结构空间;分析了文化记忆空间营造的过程中的文化记忆要素特性,从文本、意象、仪式三系统进行文化表征、符号象征化的实践路径探讨;总结出参与—唤醒—认同的递进式活化路径,最后提出记忆重现、场景营造、记忆共创的可行性设计策略,为提升三线精神在中华民族红色精神传承中的结构性力量提供有益参考。

基于IGCT抑制换相失败的关键控制策略

针对基于电网换相换流器的高压直流(LCC-HVDC)输电系统因以晶闸管作为换流器件而存在的换相失败问题,以集成门极换流晶闸管(IGCT)在中国某背靠背高压直流工程中的应用为基础,首先介绍了IGCT型高压直流的拓扑及基本运行原理。接着,从兼顾换相失败抵御效果和IGCT阀的关断应力角度,提出了适应IGCT阀的关断策略。在此基础上,研究了不同类型交流故障对故障电流峰值的影响,提出了利用故障扰动系数动态调整电流控制器参数的策略,实现故障电流抑制和故障期间直流功率的稳定输送。最后,通过实时数字仿真(RTDS)验证了所提策略的正确性和有效性。

面向海底管道巡检的AUV三维自适应路径跟踪

针对面向海底管道巡检任务的欠驱动自主水下航行器(AUV)三维路径跟踪控制问题进行研究。首先,在固定坐标系和机体坐标系下建立AUV的运动学模型,为设计适宜运动控制的三维路径跟踪控制器,建立流体坐标系,并在Serret-Frenet坐标系下建立AUV的路径跟踪误差模型;其次,将可变前视距离引入传统视线(LOS)制导策略,提出一种自适应LOS制导策略以提高制导精度,并基于此设计面向海底管道巡检的AUV三维路径跟踪控制器,使得AUV可有效跟踪设定的参数化路径;最后,基于李雅普诺夫稳定性理论证明了闭环系统的稳定性。仿真结果验证了所提面向海底管道巡检的三维路径跟踪控制器的有效性。研究成果能够改善AUV的操纵性,可为面向海底管道巡检的无人水下航行器路径跟踪控制方法提供参考。

结合局部纹理特征滤波的海天线检测方法

针对视频监测下海天线检测图像易出现的海天对比度低、海上物体、海雾、海浪及云层等干扰条件引起的图像模糊和海天线遮挡问题,提出一种基于偏心邻域的灰度共生矩阵对比度滤波的梯度域下海天线检测方法。方法设计使用上下两方向偏心盒状滤波器获取图像的对比度梯度值图,利用滑动窗对分块图像搜索梯度极大值候选位置,根据设计策略通过构建海天线参数的概率统计模型提取拟合直线作为检测结果。仿真实验表明,本文方法能提升视觉图像下含多景物等干扰的复杂场景海天线检测的准确率,与同类方法相比提升7.69%。

一种监测母线槽的无线传感器信号采样策略

母线槽信号包含大量平稳信号和部分突发情况信号,完整准确地采集其信号能够保证母线槽的稳定运行。保持高上传率可准确地采集到信号,但功耗过大,降低设备使用寿命。文章提出一种适用母线槽信号的无线传感器节点近似采样策略(approximate sampling method,ASM),通过分析所采数据的相对变化程度及变化趋势捕捉完整突发情况信号,水塘抽样算法剔除部分无效平稳数据,完整准确地上传母线槽状态趋势信号。通过Matlab仿真表明ASM采样策略相比于SOD(send-on-delta)、无线传感器节点动态采样策略(dynamic sampling internal,DSI),无效采样率、变化偏移量更小,降低了能耗且保证了采样信号完整。

基于深度学习和无人机图像的架空线路缺陷巡检综述

架空输电线路巡检是电网运维工作的一项重要内容,利用无人机进行线路巡视检测已成为运维人员完成电力巡检工作的重要手段。首先,文中概述无人机巡检任务中人机协同作业系统以及无人机智能自主作业系统的架构;其次,分析当前架空输电线路缺陷巡检领域数据集状况以及数据扩增技术;再次,综述基于深度学习的无人机图像缺陷检测典型方法以及评价指标,并对比总结各种方法的优缺点;然后,讨论无人机图像视觉检测方法中图像采集规范、数据集形式、缺陷检测算法专业化应用等对架空线路缺陷的检测效果,指出图像检测指标和类别定义在电力巡检专业化领域中的不足;最后,探讨基于深度学习的无人机图像缺陷巡检的未来发展方向。

受体动脉不同临时阻断策略在烟雾病颞浅动脉-大脑中动脉搭桥术中的应用比较

目的探讨颞浅动脉-大脑中动脉端侧吻合术中不同临时阻断技术的效果及可靠性。方法回顾性分析2015年1月—2023年4月南方医科大学南方医院神经外科收治的接受直接搭桥术治疗的烟雾病患者资料,根据临时阻断策略的不同将患者分为3组:①有垫片、多阻断夹阻断组(multi-clips+rubber pad group,M+R组);②无垫片、多阻断夹阻断组(multi-clips group,M组);③无垫片、单阻断夹阻断组(single-clip group,S组)。比较组间临时阻断时间、受体动脉切开后有无渗血、术中穿支血管损伤以及术后新发脑梗死情况。结果共355例患者、360个大脑半球纳入分析,按大脑半球统计患者360例,其中男性188例,女性172例,平均年龄为(43.8±0.7)岁。其中M+R组45例,M组191例,S组124例。3组平均阻断时间:M+R组为(37.9±9.8)min,M组为(20.9±9.0)min,S组为(11.0±3.5)min,组间差异有统计学意义(P<0.001)。阻断后受体动脉管腔内渗血以及术中穿支血管损伤发生率:M+R组为8.89%(阻断后受体动脉渗血4例),M组为14.66%(阻断后受体动脉渗血19例,术中穿支血管损伤8例,临时阻断部位有血栓形成1例),S组为5.65%(阻断后受体动脉渗血7例),组间差异无统计学意义(P>0.05)。术后新发脑梗死发生率差异无统计学意义(P>0.05)。结论单阻断夹阻断策略安全、有效,能显著缩短临时阻断时间,可以优先考虑作为颞浅动脉-大脑中动脉端侧吻合过程中的临时阻断策略。

基于“虚拟碳储存”的需求侧电-碳耦合交易机制

“双碳”目标指引下,电力系统低碳转型势在必行。结合时变价格信号的低碳需求响应可以引导用户调整用电行为降低碳排放。然而,不同用户灵活性差异较大,仅通过价格信号的变化难以引导低灵活性用户实现碳减排;同时,部分高灵活性用户的调节潜力并未被完全释放。为了通过用户间碳排放责任的交易进一步释放需求侧的碳减排潜力,该文提出需求侧电-碳耦合交易机制,旨在通过碳排放责任的再分配进一步释放高灵活性用户的碳减排潜力。但根据比例共享定理,碳排放责任与用电量成固定比例,限制其在用户间的灵活转移,提出“虚拟碳储存”,使储能中电的碳排放强度成为可控变量,实现碳排放责任在用户间的自由转移。以地区电力系统为研究场景,综合考虑电费成本、碳排放成本以及负荷调节成本,引入近端策略优化算法求解用户的最佳用电策略。仿真结果显示,相比用户仅参与传统电力市场,参与电-碳耦合市场并考虑“虚拟碳储存”,可减少31.9%的碳排放,同时显著降低了用户用电成本。