A lightweight autonomous MAV for indoor search and rescue

Micro Aerial Vehicles (MAVs) have great potentials to be applied for indoor search and rescue missions. In this paper, we propose a modular lightweight design of an autonomous MAV with integrated hardware and software. The MAV is equipped with the 2D laser scanner, camera, mission computer and flight controller, running all the computation onboard in real time. The onboard perception system includes a laser‐based SLAM module and a custom‐designed visual detection module. A dual Kalman filter design provides robust state estimation by multiple sensor fusion. Specifically, the fusion module provides robust altitude measurement in the circumstance of surface changing. In addition, indoor‐outdoor transition is explicitly handled by the fusion module. In order to efficiently navigate through obstacles and adapt to multiple tasks, a task tree‐based mission planning method is seamlessly integrated with path planning and control modules. The MAV is capable of searching and rescuing victims from unknown indoor environments effectively. It was validated by our award‐winning performance at the 2017 International Micro Air Vehicle Competition (IMAV 2017), held in Toulouse, France. The performance video is available on https://youtu.be/8H19ppS_VXM .     

A survey and taxonomy on virtual data center embedding

The Journal of Supercomputing - Data center network virtualization is being considered as a promising technology to provide a performance guarantee for cloud computing applications. One important...     

A Potent Mimetic of the Siglec-8 Ligand 6’-Sulfo-Sialyl Lewisx

Siglecs are members of the immunoglobulin gene family containing sialic acid binding N-terminal domains. Among them, Siglec-8 is expressed on various cell types of the immune system such as eosinophils, mast cells and weakly on basophils. Cross-linking of Siglec-8 with monoclonal antibodies triggers apoptosis in eosinophils and inhibits degranulation of mast cells, making Siglec-8 a promising target for the treatment of eosinophil- and mast cell-associated diseases such as asthma. The tetrasaccharide 6’-sulfo-sialyl Lewis^x has been identified as a specific Siglec-8 ligand in glycan array screening. Here, we describe an extended study enlightening the pharmacophores of 6’-sulfo-sialyl Lewis^x and the successful development of a high-affinity mimetic. Retaining the neuraminic acid core, the introduction of a carbocyclic mimetic of the Gal moiety and a sulfonamide substituent in the 9-position gave a 20-fold improved binding affinity. Finally, the residence time, which usually is the Achilles tendon of carbohydrate/lectin interactions, could be improved.     

LNG冷量优化集成利用技术

我国将相继在沿海地区建成多个LNG接收站，每年将进口数以千万吨计的LNG，同时携带数着巨额冷量，而这些冷量可用于发电、空气分离、制造干冰、低温冷库等众多领域。基于国外LNG冷量利用现状，指出我国即将展开和实施此项技术还存在着：过程火用损较大，缺乏系统、全面的LNG冷量利用技术的研发指导机制，以及宏观调控力度薄弱等问题，进而提出了发展LNG冷量的集成利用方案，可为此类技术的研发利用提供新思路。以福建即将进口的LNG为例，模拟了空气分离与干冰制备的集成工艺流程，结果表明：福建每年进口的260×10⁴t LNG可以冷却290×10⁴t空气，相当于60000 m³/h的氧气制备规模，还可以生产100×10⁴t的干冰，其过程火用损较小；其剩余的高温位冷量可应用于低温冻结库或冰灯等项目，这对主体装置的实施效果和过程火用损的影响较小。该技术的优点在于可灵活控制冷却空气的液化率，基本不用冷却循环水，流程简单，设备投资少，能耗低等。     

Assay of oral vaccination of dogs against rabies in Tunisia with the vaccinal strain SADBern

The possibility of immunizing dogs orally against rabies, using SADBern, an attenuated strain, was tested on dogs in the field in Tunisia. This strain induced high neutralizing antibody titres and conferred to all vaccinated dogs total resistance against a challenge with a Maghrebian strain. However, an excretion of virus of vaccinal origin was observed in one dog, hampering the use of SADBern in dogs. Nevertheless, this work demonstrates for the first time that dogs in developing countries, especially those which are inaccessible to parenteral vaccination, could be efficiently immunized against rabies by the oral route.     

基于过程能量综合优化的延迟焦化装置扩大生产能力改造策略

根据延迟焦化流程的特点，分析了延迟焦化装置扩大生产能力的瓶颈，探讨了基于能量综合优化的装置扩能解除瓶颈的策略方法，基于过程能量综合优化，运用流程模拟技术，通过配套的加热炉优化，分馏塔操作优化，换热网络柔性设计等手段，实现了装置扩大生产能力的目的，并运用所提出的策略对某延迟焦化装置进行了基于能量系统优化的扩能改造，在原流程与设备的基础上，装置处理量增大18．2％，装置物耗，能耗大幅度降低，改造设备投资少，说明能量综合优化对工艺装置扩能改造具有重要意义。     

A new boundary finite element method for fluid–structure interaction problems

In order to study problems on fluid–structure interaction, we have used a mixed formulation which couples the classical functional of the structure with a new variational formulation by integral equations for the fluid. This formulation has the advantage over the finite element methods of avoiding the discretization of the fluid domain. Furthermore, unlike collocation methods, the explicit calculation of the Hadamard finite part of the singular integrals is avoided. This leads after discretization by boundary finite elements to a small and symmetrical algebraic system. Typical examples are presented that demonstrate the efficiency of this variational formulation by studying the sound transmission through a baffled plane structure and through a flexible panel backed by a rigid cavity. These include the calculation of the transmission loss factor and the determination of which modes dominate the noise transmission. Good agreement is obtained between numerical results and analytical results found in the literature.     

Performance comparison of space-time block coded and cyclic delay diversity MC-CDMA systems

Spatial diversity is a widely applied technique for enhancing wireless system performance since it greatly reduces the detrimental effects of multipath fading. Space-time block codes have been considered the best choice for transmit diversity in narrowband environments, but their use in broadband channels is questionable due to their inability to pick up multipath diversity. However, when used in conjunction with an MC-CDMA system, they achieve not only full spatial but also variable multipath diversity depending on the employed spreading. In comparison, cyclic delay diversity is an attractive approach to achieve spatial and multipath diversity. Its simplicity and conformability with current standards makes it desirable for multicarrier systems. Previous studies suggest that CDD is only advantageous with an outer channel code for OFDM systems. In this article, we compare STBCs and CDD applied to an MC-CDMA system in terms of complexity and performance. It is shown that for an MC-CDMA system, CDD benefits from spreading and channel coding that makes it very competitive with STBCs, particularly since it is applicable to any number of transmit antennas with no loss in rate.