Cooperative Sampling Path Planning of Underwater Glider Fleet with Simultaneous Launch and Recovery

As low-cost and highly autonomous ocean observation platforms,underwater gliders encounter risks during their launch and recovery,especially when coordinating multi-glider deployments.This work focuses on cooperative path planning of an underwater glider fleet with simultaneous launch and recovery to enhance the autonomy of sampling and reduce deployment risks.Specifically,the gliders collaborate to achieve sampling considering the specified routines of interest.The overall paths to be planned are divided into four rectangular parts with the same starting point,and each glider is assigned a local sampling route.A clipped-oriented line-of-sight algorithm is proposed to ensure the coverage of the desired edges.The pitch angle of the glider is selected as the optimizing parameter to coordinate the overall progress considering the susceptibility of gliders to currents and the randomness of paths produced by complex navigational strategies.Therefore,a multi-actuation deep-Q network algorithm is proposed to ensure simultaneous launch and recovery.Simulation results demonstrate the acceptable effectiveness of the proposed method.

Cooperative Loss Recovery for Reliable Multicast in Ad Hoc Networks

Providing reliable multicast service is very challenging in Ad Hoc networks. In this paper, we propose an efficient loss recovery scheme for reliable multicast (CoreRM). Our basic idea is to apply the notion of cooperative communications to support local loss recovery in multicast. A receiver node experiencing a packet loss tries to recover the lost packet through progressively cooperating with neighboring nodes, upstream nodes or even source node. In order to reduce recovery latency and retransmission overhead, CoreRM caches not only data packets but also the path which could be used for future possible use to expedite the loss recovery process. Both analytical and simulation results reveal that CoreRM significantly improves the reliable multicast performance in terms of delivery ratio, throughput and recovery latency compared with UDP and PGM.

Topology Recovery Technique for Complex Freeform Surface Model after Local Geometry Repair

Intersections and discontinuities commonly arise in surface modeling and cause problems in downstream operations. Local geometry repair, such as cover holes or replace bad surfaces by adding new surface patches for dealing with inconsistencies among the confluent region, where multiple surfaces meet, is a common technique used in CAD model repair and reverse engineering. However, local geometry repair destroys the topology of original CAD model and increases the number of surface patches needed for freeform surface shape modeling. Consequently, a topology recovery technique dealing with complex freeform surface model after local geometry repair is proposed. Firstly, construct the curve network which freeform surface model; secondly, apply freeform surface fitting method determine the geometry and topology properties of recovery to create B-spline surface patches to recover the topology of trimmed ones. Corresponding to the two levels of enforcing boundary conditions on a B-spline surface, two solution schemes are presented respectively. In the first solution scheme, non-constrained B-spline surface fitting method is utilized to piecewise recover trimmed confluent surface patches and then employs global beautification technique to smoothly stitch the recovery surface patches. In the other solution scheme, constrained B-spline surface fitting technique based on discretization of boundary conditions is directly applied to recover topology of surface model after local geometry repair while achieving G~ continuity simultaneously. The presented two different schemes are applied to the consistent surface model, which consists of five trimmed confluent surface patches and a local consistent surface patch, and a machine cover model, respectively. The application results show that our topology recovery technique meets shape-preserving and Gt continuity requirements in reverse engineering. This research converts the problem of topology recovery for consistent surface model to the problem of constructing G1 patches from a given curve network, and provides a new idea to model repairing study.

Oscillating field stimulation promotes neurogenesis of neural stem cells through miR-124/Tal1 axis to repair spinal cord injury in rats

Spinal cord injury often leads to severe motor and sensory deficits,and prognosis using the currently available therapies remains poor.Therefore,we aimed to explore a novel therapeutic approach for improving the prognosis of spinal cord injury.In this study,we implanted oscillating field stimulation devices and transplanted neural stem cells into the thoracic region(T9–T10)of rats with a spinal cord contusion.Basso-Beattie-Bresnahan scoring revealed that oscillating field stimulation combined with neural stem cells transplantation promoted motor function recovery following spinal cord injury.In addition,we investigated the regulation of oscillating field stimulation on the miR-124/Tal1 axis in neural stem cells.Transfection of lentivirus was performed to investigate the role of Tal1 in neurogenesis of neural stem cells induced by oscillating field stimulation.Quantitative reverse transcription-polymerase chain reaction,immunofluorescence and western blotting showed that oscillating field stimulation promoted neurogenesis of neural stem cells in vitro and in vivo.Hematoxylin and eosin staining showed that oscillating field stimulation combined with neural stem cells transplantation alleviated cavities formation after spinal cord injury.Taking the results together,we concluded that oscillating field stimulation decreased miR-124 expression and increased Tal1 content,thereby promoting the neurogenesis of neural stem cells.The combination of oscillating field stimulation and neural stem cells transplantation improved neurogenesis,and thereby promoted structural and functional recovery after spinal cord injury.

The proteome of distal nerves: implication in delayed repair and poor functional recovery

Chronic denervation is one of the key factors that affect nerve regeneration.Chronic axotomy deteriorates the distal nerve stump,causes protein changes,and renders the microenvironment less permissive for regeneration.Some of these factors/proteins have been individually studied.To better delineate the comprehensive protein expression profiles and identify proteins that contribute to or are associated with this detrimental effect,we carried out a proteomic analysis of the distal nerve using an established delayed rat sciatic nerve repair model.Four rats that received immediate repair after sciatic nerve transection served as control,whereas four rats in the experimental group(chronic denervation)had their sciatic nerve repaired after a 12-week delay.All the rats were sacrificed after 16 weeks to harvest the distal nerves for extracting proteins.Twenty-five micrograms of protein from each sample were fractionated in SDS-PAGE gels.NanoLC-MS/MS analysis was applied to the gels.Protein expression levels of nerves on the surgery side were compared to those on the contralateral side.Any protein with a P value of less than 0.05 and a fold change of 4 or higher was deemed differentially expressed.All the differentially expressed proteins in both groups were further stratified according to the biological processes.A PubMed search was also conducted to identify the differentially expressed proteins that have been reported to be either beneficial or detrimental to nerve regeneration.Ingenuity Pathway Analysis(IPA)software was used for pathway analysis.The results showed that 709 differentially expressed proteins were identified in the delayed repair group,with a bigger proportion of immune and inflammatory process-related proteins and a smaller proportion of proteins related to axon regeneration and lipid metabolism in comparison to the control group where 478 differentially expressed proteins were identified.The experimental group also had more beneficial proteins that were downregulated and more detrimental proteins that were upregulated.IPA revealed that protective pathways such as LXR/RXR,acute phase response,RAC,ERK/MAPK,CNTF,IL-6,and FGF signaling were inhibited in the delayed repair group,whereas three detrimental pathways,including the complement system,PTEN,and apoptosis signaling,were activated.An available database of the adult rodent sciatic nerve was used to assign protein changes to specific cell types.The poor regeneration seen in the delayed repair group could be associated with the down-regulation of beneficial proteins and up-regulation of detrimental proteins.The proteins and pathways identified in this study may offer clues for future studies to identify therapeutic targets.

考虑移动式储能的综合能源系统冰灾后抢修与调度协同优化

冰灾易造成大规模停电事故,此时综合能源系统中的热电耦合设备可协调电出力和热出力,降低损失。根据典型的气象数据模拟冰灾故障场景,建立除冰抢修、综合能源系统与移动式储能系统双层协同优化调度模型,以减少冰灾带来的不利影响。上层优化模型为保障综合能源系统的电网快速恢复供电的除冰抢修调度模型,下层优化模型为综合能源系统与移动式储能系统调度模型,上层的各故障线路除冰抢修进度与下层的各节点实时切负荷情况相互传递、交互优化,保障在短时间内抢修更多的故障线路的同时恢复更多的用电负荷,并充分利用热电联产机组灵活的热电比以优化综合能源系统调度,有效减少系统整体经济损失。另外,下层优化模型依据故障后综合能源系统的切负荷情况调度移动式储能系统,进一步减少系统切负荷损失,同时可提高综合能源系统韧性。通过算例仿真验证所提方法的有效性。

炼化企业挥发性有机化合物减排的探索与实践

炼化企业加工过程有组织、无组织排放的挥发性有机化合物(VOCs)量较大,对大气环境中的颗粒物、臭氧浓度等产生重大影响。A公司自“十三五”以来对VOCs减排进行了探索与实践,通过采取油气回收、储罐浮盘高效密封改造、呼吸阀改型升级、无组织排放改为有组织回收、VOCs焚烧、常态化泄漏检测与修复工作等多种减排措施,VOCs排放量已从2015年的4230 t下降到2022年的2157 t,降低比例达到49%,取得了显著的成效。

台风场景下基于多种分布式资源协同的弹性配电网两阶段供电恢复策略

近年来频发的自然灾害极大威胁配电网安全运行,统筹考虑不同分布式资源特点,发挥分布式资源互补互济优势,有助于解决灾后配电网部分线路损坏、电力供应不足问题,实现电网灾后快速恢复。在电网中分布式资源种类不断丰富的背景下,本文提出一种台风场景下基于多种分布式资源协同的弹性配电网灾前及灾后两阶段供电恢复策略。首先,考虑配电网和交通网耦合的影响,灾前阶段在考虑电动汽车调度的同时,以加权失电量期望最小为目标建立移动储能和抢修队应急仓库选址模型;其次,根据以上3种分布式资源以及柔性负荷的灾后响应特征,将灾后阶段分为紧急功率支撑和负荷快速恢复两个过程,搭建了配电网灾后多时段恢复优化模型;然后,通过深入研究多种分布式资源的优缺点,设计了配电网两阶段供电恢复框架;最后,设计了多组算例,验证了所提方法的有效性和可行性。

韧带修复术对踝关节骨折合并三角韧带损伤患者骨代谢、促进恢复的作用分析

目的探讨韧带修复术对踝关节骨折合并三角韧带损伤患者骨代谢、促进恢复的作用。方法选择2019年1月至2022年1月成都市龙泉驿区中医医院骨科收治的111例踝关节骨折合并三角韧带损伤患者,采用随机数表法分为试验组(n=56)和对照组(n=55)。对照组给予切开复位钢板内固定术治疗,试验组加用韧带修复术治疗。比较两组术后恢复率、骨代谢、踝关节活动情况、临床评分变化情况及不良反应发生情况。结果术后试验组踝关节功能恢复优良率高于对照组(P<0.05);治疗后两组骨代谢及临床评分均改善,且试验组改善程度优于对照组(P<0.05);两组外翻角、外翻力度均升高,踝关节内侧间隙降低,且试验组优于对照组(P<0.05);两组不良反应比较差异无统计学意义(P>0.05)。结论在踝关节骨折合并三角韧带损伤中应用韧带修复术疗效显著,可有效改善患者骨代谢、促进恢复。

补片形式对蒙皮复合材料孔边裂纹修复效果的影响

针对蒙皮复合材料孔边裂纹,提出了共固化补片修复和预固化补片修复两种修复方式,并设计了与之适配的修复方案,研究了修复方式对试样抗拉强度恢复效果的影响,阐明了完好试样和各类修复试样的断裂失效机制。结果表明:相同补片尺寸下,预固化补片修复试样的强度恢复率均高于共固化补片修复试样,预固化补片修复试样强度恢复率最高为81.9%,且试样断口平齐,补片与复合材料层压板之间的断裂机制为纤维纵向拉断;共固化补片修复试样强度恢复率最高为78.6%,主要断裂机制为复合材料层压板分层。证明了相比于共固化补片修复,预固化补片修复试样能够恢复更高的抗拉强度,为蒙皮复合材料修复提供了具体的工艺方案和理论基础。

一种基于多层次校验的低恢复成本纠删码

随着纠删码在分布式存储系统中的实际应用,纠删码为存储系统提供了更加优秀的存储效率,但当节点丢失时,相较于传统副本技术更多的网络传输带宽开销成为了造成系统性能瓶颈的关键因素。为了解决MDS编码高带宽开销对系统性能的影响,一类新型编码方案——分组码被应用在分布式存储系统中,相较于传统MDS编码能够有效地降低节点修复时的数据传输量,从而减少网络带宽需求。在Pyramid分组码的基础上进行层次扩展,提出一种HLRC(hierarchical local repair codes)纠删码。HLRC相较于LRC引入了层次编码模型,将原始数据块构建为编码矩阵,根据层次进行分别编码,生成包含数据块范围不同的局部校验块;每个层次包含的数据块数量不同,可以保证修复节点时的低修复成本,同时还拥有较高的存储效率。HLRC相较于Pyramid拥有额外的校验块冗余,能够降低校验块出错和多节点出错时的恢复开销。在基于Ceph的分布式存储系统中的实验结果表明,HLRC与Pyramid等分组码相比,单节点修复开销最高可降低48.56%,多节点修复开销最高可降低25%。

基于加速康复外科理念的多学科合作管理对二次剖宫产产妇术后恢复及早期转归的影响

目的探讨基于加速康复外科(ERAS)理念的多学科合作管理对二次剖宫产产妇术后恢复及早期转归的影响。方法选择2022年12月至2024年3月于济宁市第一人民医院行二次剖宫产手术的产妇60例,采用随机数字表法分为常规组和ERAS组,各30例。常规组给予传统管理方案,ERAS组给予基于ERAS理念的多学科合作管理方案。比较两组产妇术后恢复情况、术后镇痛情况及术后并发症发生情况。结果ERAS组产妇术后24h 11项产科恢复质量(ObsQoR-11)评分为(92.90±7.16)分高于常规组(85.20±11.86)分,术后首次排气时间为(25.17±4.91)h、初始泌乳时间为(21.20±1.67)h分别短于常规组(29.80±5.11)h和(25.67±3.04)h,子宫复旧程度为(2.26±0.71)cm大于常规组(1.67±0.42)cm,术后48h舒芬太尼用量为[50.00(48.00,52.00)]μg少于常规组[52.00(48.00,56.00)]μg,差异有统计学意义(t=3.044、-3.583、-7.048、3.908,Z=-2.354,均P<0.05)。ERAS组术后静息及咳嗽时中重度疼痛发生率、镇痛补救率、术后并发症总发生率分别为6.67%、10.00%、6.67%、26.67%,均明显低于常规组的26.67%、33.33%、30.00%、73.33%,差异有统计学意义(χ^(2)=4.320、4.812、5.455、13.067,均P<0.05)。结论基于ERAS理念的多学科合作管理有利于促进二次剖宫产产妇术后恢复,降低并发症,改善术后早期转归。

基于CEI测量的GEO目标快速轨道恢复

连线干涉测量(Connected Element Interferometry,CEI)是一种全天时全天候的被动测角技术,已用于空间目标的跟踪监视.地球静止轨道(Geostationary Earth Orbit,GEO)卫星需要频繁机动以保持轨位或完成其他任务,其机动后的快速轨道恢复能力对于监视预警极为重要.针对基于CEI的GEO短弧定轨和预报,分析了定轨算法的形亏和数亏,在附加先验轨道约束的短弧定轨基础上,提出了轨道半长轴初值的自适应优化方法.利用亚太七号卫星的CEI仿真和实测数据进行了短弧定轨和预报,实验结果表明,采用优化后的半长轴初值,30min短弧定轨和10min预报的卫星位置分量精度均优于4km,能够满足非合作GEO目标机动后快速轨道恢复的需求.

台风灾害下考虑修复不确定性和V2G的弹性城市电网动态供电恢复方法

快速可行的灾后恢复是弹性电力系统的重要一环。提出一种弹性导向的考虑修复不确定性和V2G(vehicle to grid,V2G)的城市电力系统动态供电恢复方法,灾后短期内应用V2G站中的有限电动汽车资源为城市电网提供电能支撑,同时派遣抢修队对故障线路进行抢修作业,实现系统快速恢复。对V2G和电动汽车灾前、灾后行为进行建模,通过灾前自由调度统计各V2G站附近的电动汽车数量,按照响应意愿比例得到灾后阶段各V2G站反向输电功率;对包含行驶行为和修复行为的动态修复行为进行建模,采用滚动时域优化方法决策修复的先后顺序,得到抢修队最优动态修复方案。最后,设计多组算例以验证所提方法的可行性,结果表明,该方法可有效支撑灾后城市电力系统快速恢复,提高系统弹性。

Silk-based nerve guidance conduits with macroscopic holes modulate the vascularization of regenerating rat sciatic nerve

Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). However, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimization of the macroscopic holes silk^(+) tNGC approach containing macroscopic holes might result in improved grafting technology suitable for future clinical use.

基于区块链的闭环供应链定价及回收策略

考虑区块链技术下新能源汽车闭环供应链定价及回收决策问题,构建制造商和零售商回收模式下链上成员Stackelberg(斯塔克尔伯格)博弈模型。结果表明,随着消费者对绿色产品偏好提升,碳减排努力、链上成员利润及社会福利等均增长;提高梯次利用比例将增加零售商回收模式下零售商利润、两种回收模式下制造商利润及社会福利,尤其引入区块链及制造商回收对社会福利影响显著;采用区块链单位成本满足一定阈值时,采用区块链有利于提升需求量和碳减排努力。

考虑动态交通网络的区域电-气互联系统灾后故障抢修策略

为了减弱极端事件对综合能源系统的影响,尽早恢复各类负荷,提高系统弹性。文中提出了一种考虑交通网与配电网级别的区域电-气互联系统(Interconnection Electric and Gas System, IEGS)协同运行的灾后故障抢修策略。首先,通过元胞传输模型建立了考虑系统实时恢复指标修正的交通流量分配模型,对交通网的交通流量进行预测;其次,在故障预分配的前提下建立了区域IEGS的故障恢复模型,协调优化维修队、分布式电源、配电网网架等资源,减少停电损失;然后以维修队的最小通行时间矩阵以及由系统实时恢复指标得到的交通网道路修正参数作为传递变量,在维修队开始移动的时间点,重新计算后续的修复计划以及交通网的运行情况,进行多时间断面优化;最后,通过算例仿真进行对比,验证了所提策略的有效性,并分析移动储能装置对故障恢复的影响。

违约债券回收事件对同行业债券发行定价的影响研究——兼论债券行业的信用修复路径

为改善我国债券市场上违约债券的回收现状,有必要对回收事件的经济效应进行研究,探讨债券市场是否存在对回收行为的正向激励,从而为完善信用激励惩戒制度提供参考。基于信号理论,本文利用2015-2021年我国债券市场上的回收数据及发行数据研究回收事件对债券发行利差的影响。研究发现,公司债券发行前同行业的回收事件可显著降低债券的发行利差,即回收事件的信用修复效应显著。机制检验发现,回收事件通过影响信用评级及投资者情绪实现信用修复效应。异质性分析显示,回收事件的信用修复效应将被违约事件削弱甚至超越;存在隐性担保的企业、非周期性行业、轻资产行业中信用修复效应更突出。本文的研究证实了债券市场存在对回收行为的正向激励,有助于监管机构完善信用激励惩戒制度,也有助于发债企业择时进行债券发行以降低融资成本。

手术室护理配合路径用于宫腔镜下子宫内膜息肉切除术效果分析

目的探讨手术室护理配合路径在宫腔镜下子宫内膜息肉切除术中的应用效果。方法选取医院2022年3月至2023年7月收治的行宫腔镜下子宫内膜息肉切除术的患者100例,随机分为对照组和观察组,各50例。对照组患者予常规手术室护理,观察组患者予特定的手术室护理配合路径。结果观察组患者的手术时间、术后恢复时间均显著短于对照组(P<0.05);观察组患者的满意度评分显著高于对照组(P<0.05);观察组患者的并发症发生率为4.00%,显著低于对照组的20.00%(P<0.05)。结论手术室护理配合路径用于宫腔镜下子宫内膜息肉切除术的效果良好,可降低并发症风险,加快术后恢复,提高患者满意度。

心理资本对大学生创业失败修复的影响——一个有调节的中介效应模型

作为大学生开展创业活动的重要驱动因素,心理资本是否对大学生创业失败修复也产生重要影响,是学界关注的研究问题。对全国632份创业失败大学生问卷调查数据的分析发现:心理资本对大学生创业失败修复有正向促进作用,能正向预测其创业失败修复水平;失败学习和恢复导向在其中起中介作用;经济成本负向调节心理资本通过失败学习和恢复导向影响大学生创业失败修复的程度。促进大学生创业失败修复,可从营造宽容创业失败氛围、切实提升大学生心理资本、构建大学生创业失败经济补偿机制和大学生加强失败学习准备等方面入手。