Numerical simulation of the spreading dynamic responses of the multibody system with a floating base

To simulate the dynamic responses of the multibody system with a floating base when the upper parts spread with a certain sequence and relative speed, the homogeneous matrix method is employed to model and simulate a four-body system with a floating base and the motions are analyzed when the upper parts are spread sequentially or synchronously. The rolling, swaying and heaving temporal variations are obtained when the multibody system is under the conditions of the static water along with the wave loads and the mean wind loads or the single pulse wind loads, respectively. The moment variations of each joint under the single pulse wind load are also gained. The numerical results showed that the swaying of the floating base is almost not influenced by the spreading time or form when the upper parts spread sequentially or synchronously, while the rolling and the heaving mainly depend on the spreading time and forms. The swaying and heaving motions are influenced significantly by the mean wind loads. The single pulse wind load also has influences on the dynamic responses. The torque of joint 3 and joint 4 in the single pulse wind environment may be twice that in the windless environment when the system spreads with 60 s duration.     

Topology-aware overlay multicast over IP multicast networks

Most existing overlay multicast approaches refuse to consider any network layer support no matter whether it is available or not. This design principle greatly increases the complexity of the routing algorithms and makes the overlay topologies incompatible with the underlying network. To address these issues, topologyaware overlay multicast over IP multicast networks （TOMIMN） was proposed as a novel overlay multicast protocol, which exploits the cooperation between end-hosts and IP multicast routers to construct a topologyaware overlay tree. Through a little modification to protocol independent multicast sparse mode （PIM-SM）, a multicast router is able to receive registration from nearby group members and redirect passing-by join requests to them. Due to the multicast router＇s support, TOMIMN organizes its group members into an overlay multicast tree efficiently, which matches the physical network topology well.     

上海长江大桥跨江段桥梁设计

上海长江大桥全长16．5km,是目前我国最大的公路与轨道交通合建的跨江桥梁。设计中根据大桥的建设条件与特点,开发与应用了公轨合建、大跨度斜拉桥、大跨度组合梁、大型预制构件、节段拼装主梁等新技术、新结构、新工艺,为大桥的建设提供了技术支撑。该文着重介绍了上海长江大桥跨江段桥梁的设计与科研。     

船用带经济器的离心式空调系统的理论分析与试验研究

为实现船舶空调系统的节能降耗,将带有经济器的离心式空调系统引入到船舶空调系统中。在定蒸发温度/变冷凝温度工况下,通过理论分析和试验研究,在验证带有经济器的离心式空调系统适用于船舶的同时,探究系统性能参数随冷凝温度的变化规律。结果表明:将带有经济器的离心式空调系统应用于船舶空调系统中是可行的;系统性能参数的理论模拟值和试验测得值随冷凝温度的变化趋势一致,理论值优于试验值,压缩机的排气温度和功率随冷凝温度的升高而增高,系统制冷量和制冷能效比(EER)随冷凝温度的升高而下降,EER介于6.87～10.14之间。     

19 000 t化学品/油船主要内外舾装设计

本文描述了19 000 t化学品/油船的锚设备、系泊设备、燃油管吊和泵吊的布置、货油舱盖和梯的设计、窗和室内梯的设计。     

Improved Anchored Neighborhood Regression Enhancement for Face Recognition

Although progress in face recognition is encouraging, the accuracy rate of face recognition remains to be increased. Since the face image quality has a positive influence on face recognition accuracy, the image enhancement methods are popular in face recognition. Most current image enhancement methods aim at improving visual appearance, but cannot improve recognition accuracy remarkably. In this paper, a feature evaluation operator is designed to overcome this problem. The operator selects patches with the best quality, and then face image is reconstructed with the selected patches. The proposed algorithm is tested on two different face recognition applications. Accuracy is raised after enhancement, and the result proves that the proposed algorithm is effective.     

龙溪口库区粉土地基上建设胶固土(石)堤防试验研究

针对龙溪口库区大量粉土地基不能直接作为堤防的持力层，且粉土废弃带来诸多环保方面不利影响等问题，开展了固化土(加石或不加石)筑堤材料的试验研究。通过一定量的胶凝材料和专用外加剂将土(石)胶结固化后，具有一定力学强度和抗渗性能等优点，胶固土(石)经过3 a泡水后未崩解，满足筑堤材料的强度要求。经过处理的粉土地基上建设胶固土(石)堤防具有创新性，新的建堤材料使粉土得到废物利用，固结材料特性比传统土石坝的散粒体材料具有更高的安全性，拓宽了建堤材料的应用范围，具有较好的推广应用价值。