铣刨机输料速度自适应液控系统研究

目前铣刨机输料速度采用开环调节,不能跟随铣刨速度和铣刨深度调节.采用输料速度自适应控制,使输料速度自动跟随铣刨速度和深度的变化,提高了皮带的使用寿命和液压系统能量利用率.     

舰船航姿发送系统的数字化改进设计

随着现代惯性导航设备（特别是捷联导航设备）的发展,惯性测量单元（IMU）大多以数字平台的方式存在,发送数字信号简单而方便;为兼容一些设备的模拟电机接收,对原有的舰船航姿发送系统进行数字化改进就显得十分必要了。该文提出了某舰船航姿发送系统的数字化改进设计的原理、方案和实现的一些关键措施,并列举了该系统的特点和与原系统的优势所在。     

众包配送研究综述

基于SCI数据库和CNKI数据库收录的1 495个文献,应用知识图谱分析软件VOSviewer对众包配送共词进行聚类分析,梳理了众包配送参与主体的影响因素、众包配送平台的运营和众包配送车辆路径问题,分析了国内外众包配送的现状,探讨了众包配送存在的问题,提出了众包配送未来的发展方向。研究结果表明：在众包参与主体方面,价格、安全和配送难度等是影响众包配送模式普及的重要因素;在平台运营方面,现有众包配送运营平台以成本最小或路径最短为目标,构建单一的任务匹配函数;在车辆路径问题方面,现有众包配送多依托已有数据库采用启发式算法求解车辆路径问题。未来众包配送研究的发展趋势主要包括：对众包参与主体影响因素进行研究,为吸引不同特征的参与主体,适应区域客户密度和经济发展水平差异,应合理调整配送价格,进一步细化场景;为提升众包配送平台服务水平,提高众包配送平台竞争力,应将安全、资源、环境与交通等因素纳入配送平台中,构建多目标任务匹配函数;为适应众包配送特性,提高众包配送系统响应速度,应构建具有优先级的多目标路径优化函数;应利用人工智能算法等工具,解决众包配送路径优化问题。     

Route design for last-in,first-out deliveries with backhauling

The retail route design problem extends the capacitated vehicle routing problem with time windows by introducing several operational constraints, including order loading and delivery restrictions (last-in, first-out), order-dependent vehicle capacity, material handling limits at the warehouse, backhauling, and driving time bounds. In this paper, the problem is modeled on a directed network for an application associated with a major grocery chain. Because the corresponding mixed-integer program proved too difficult to solve with commercial software for real instances, we developed a greedy randomized adaptive search procedure (GRASP) augmented with tabu search to provide solutions. Testing was done using data sets provided Kroger, the largest grocery chain in the US, and benchmarked against a previously developed column generation algorithm. The results showed that cost reductions of $4887 per day or 5.58% per day on average, compared to Kroger’s corresponding solutions.     

The Share-a-Ride problem with stochastic travel times and stochastic delivery locations

We consider two stochastic variants of the Share-a-Ride problem: one with stochastic travel times and one with stochastic delivery locations. Both variants are formulated as a two-stage stochastic programming model with recourse. The objective is to maximize the expected profit of serving a set of passengers and parcels using a set of homogeneous vehicles. Our solution methodology integrates an adaptive large neighborhood search heuristic and three sampling strategies for the scenario generation (fixed sample size sampling, sample average approximation, and sequential sampling procedure). A computational study is carried out to compare the proposed approaches. The results show that the convergence rate depends on the source of stochasticity in the problem: stochastic delivery locations converge faster than stochastic travel times according to the numerical test. The sample average approximation and the sequential sampling procedure show a similar performance. The performance of the fixed sample size sampling is better compared to the other two approaches. The results suggest that the stochastic information is valuable in real-life and can dramatically improve the performance of a taxi sharing system, compared to deterministic solutions.     

Experimental study on cyclosporine A drug delivery system in prevention of posterior capsule opacification after intraocular lens implantation in rabbits

Objective To study the effect of cyclosporine A drug delivery system (CsA-DDS) on the prevention of posterior capsule opacification (PCO) after experimental intraocular lens implantation in rabbit eyes. Methods Twenty healthy New Zealand white rabbits, whose left eyes and right eyes were used respectively as experiment eyes and controls, were subjected to extracapsular lens extraction and artificial lens implantation. During the operation, CsA-DDS with poly (lactideco-glycolide) as carriers or empty DDS was implanted in the capsular bag for the experimental eyes and controls respectively. After the operation, anterior chamber reaction, intraocular pressure (IOP) and CsA concentration were monitored and twelve weeks after the operation, the eyes were extracted for histopathological and morphological examinations. Results There were no differences between the two groups in conjunctival congestion,IOP change and anterior chamber reaction. PCO was less severe in the experimental eyes than in the controls. Light microscopy revealed that posterior capsular membrane in the experimental eyes was slick, with no obvious proliferation,whereas in the controls, there were lens epithelial cell proliferation and cortex regeneration of different degrees.Morphological examination with electron microscope showed that in the experimental eyes, lens epithelial cells did not function actively and apoptosis occurred, whereas in the controls, epithelial cells presented active function. No marked ultrastructural changes were found in either group. Conclusion Cs-DDS can inhibit PCO after intraocular lens implantation in rabbit eyes and does not have toxic effects on the surrounding ocular tissues. Therefore, it has a good potential for clinical use in prevention of PCO.     

有限经济批量排产和运送问题的禁忌搜索算法

探讨使用禁忌搜索算法解决一个简单的供应链经济批量排产和运送问题。其中供应商通过一个灵活的生产流水线生产多个组件并进行装配。假定所有参数,如组件的需求率等具有确定性,找到本研究的目标就是求解最优的生产批量和排序,使供应链的平均投入和运输费用最小。     

放射状专用线取送车问题模型和算法

为了解决放射形专用线取送作业的合理取送顺序、取送时机和取送次数问题,用定性与定量相结合的方法,建立取送车模型,设计求解模型的排序算法,对放射状专用线取送车问题进行优化,从而可减少非生产停留时间,依照运行图准时发车,并将调车空闲时间用于其他作业。     

谈海运货物收货人的提货义务

结合现行法律的规定,对海运货物的收货人是否应当承担提货义务,以及其承担提货义务的条件进行探讨。     

无人机在海上搜救中的应用探索

文中以无人机在搜救行动中承担的任务角色不同,分别探索无人机在实现搜寻定位、远距离视频传输和救援物资投放任务的原理和实现方式。