地理社交网络位置推荐

地理社交网络将地理位置信息融合进传统社交网络,将人们的现实生活和虚拟世界的生活连接在一起。作为地理社交网络的一个重要应用,位置推荐可以向人们推荐其可能感兴趣的位置,为人们的出行提供参考,极大地便利了人们的生活。在此背景下,论文研究了地理社交网络位置推荐的基本概念,分析了位置推荐常用的方法,描述了典型的数据集及推荐效果的评估方法,指出了位置推荐面临的主要问题,并展望了未来可能的研究方向,为相关领域的研究提供参考。     

航空加权网络抗毁性综合评估方法

根据目前网络抗毁性研究中指标单一、网络无权等不足,针对航空网络的特点,以流量为边权,提出了一种多指标的航空网络抗毁性评估方法。基于网络吞吐量、相似权网络流量、节点相邻边权重分布分别构建了鲁棒性度量、网络效率度量、网络适应性度量。最后通过建立西北地区航空网络进行仿真,结果表明:西北地区航空网络具有与星型网络相似的性能,鲁棒性较差,网络效率较好,咸阳和乌鲁木齐作为中心节点,具有较好的主抗性能。实验结果证明了该评估方法的有效性。     

基于SAR的装备维修手册生成技术

保障性分析记录(Supportability Analysis Record,SAR)是维修手册编写的基础数据来源,针对传统纸质维修手册存在的缺陷以及维修手册编写中SAR的利用率不高等问题,提出了以保障性分析记录建立底层数据环境直接生成维修手册的设计思想,构建了基于SAR的装备维修手册生成技术框架,突破了基于XML的SAR表示技术。该框架充分利用SAR数据生成维修手册,提高了分析数据的可重用性,避免了重复分析,降低了工作量,提高了维修手册生成效率。     

水面光电探测技术研究进展分析与展望

文章围绕水面光电探测技术,对该技术的内涵特点、适用范围以及主要用途进行了概括介绍．对近些年来国外在水面光电探测技术方面的发展进行了梳理,分析列举了光电探测技术发展的若干趋势,并分析了目前国内外技术间存在的差距,最后对发展我军水面光电探测技术值得重点关注的研究方向进行了分析并提出了自己的建议。     

Should competing firms reveal their capacity?

In this article, we explore when firms have an incentive to hide (or reveal) their capacity information. We consider two firms that aim to maximize profits over time and face limited capacity. One or both of the firms have private information on their own capacity levels, and they update their beliefs about their rival's capacity based on their observation of the other firm's output. We focus on credible revelation mechanisms—a firm may signal its capacity through overproduction, compared to its myopic production levels. We characterize conditions when high‐capacity firms may have the incentive and capability to signal their capacity levels by overproduction. We show that prior beliefs about capacity play a crucial, and surprisingly complex, role on whether the firm would prefer to reveal its capacity or not. A surprising result is that, despite the fact that it may be best for the high‐capacity firm to overproduce to reveal its capacity when capacity information is private, it may end up with more profits than if all capacity information were public knowledge in the first place. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

速度加姿态匹配的捷联惯导在线标定路径设计

捷联惯导误差参数的时变性对导航精度的影响很大,需要进行在外场条件下的在线标定.逆向运用PWCS可观测性分析理论,分析了“速度+姿态”匹配条件下惯导12个误差参数(陀螺和加速度计的零偏及刻度系数误差)完全可观测的条件,提出了车载惯导在线标定的路径设计原则,最后仿真验证了所设计原则的有效性.     

学习迁移理论指导下的分层式课堂活动研究

在大学的英语课堂,学生在课堂活动中的有效参与直接影响到教学效果。这就要求教师以创新的教学方式来提高学生的参与度和主动性。以学习迁移理论为依据,提出分层次实施课堂教学活动,阐释了分层式课堂活动的设计与应用,对其优势进行了分析,以期对贯彻“因材施教”教学理念起到参考作用。     

Reaction degree of composition B explosive with multi-layered compound structure protection subjected to detonation loading

The explosive reaction degree and protection from explosions are concerns in the military field.In this work,the reaction degree of the composition B explosive was investigated experimentally.Multi-layered compound structures were used as barriers to weaken the blast loads.A comprehensive experiment using a high-speed camera and image processing techniques,side witness plates,and bottom witness plates was presented.Using the experimental fragment velocities,fragment piercing patterns,and damage characteristics,the reaction degree of the explosive impeded by different multi-layered com-pound structures could be precisely differentiated.Reaction parameters of the explosive obstructed by compound structures were obtained by theoretical analysis and numerical simulations.Unlike the common method in which the explosive reaction degree is only distinguished based on the initial pressure amplitude transmitted into the explosive,a following shock wave reflected from the side steel casing was also considered.Different detonation growth paths in the explosive formed.Therefore,all these shock wave propagation characteristics must be considered to analyze the explosive response impeded by compound structures.     

Thermodynamics and performance of Al/CuO nanothermite with different storage time

The storage stability of energetic materials is important for its application. Here, the storage stability of Al/CuO nanothermite, which was prepared by electrospray method and stored with different storage time, was systematically researched. The activation energy of Al/CuO nanothermite was calculated by differential scanning calorimetry (DSC). The ignition temperature and the curve pressure history of Al/CuO nanothermite was measured using ignition temperature measuring device and constant-volume pressurization tests, respectively. Further, the thermites were characterized by X-ray Diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and Transmission electron microscopy (TEM). The results show that the morphology of the thermites did not change significantly. The activation energy was decreased from 254.1 kJ/mol to 181.8 kJ/mol after storage for 13 months. When stored for 0, 7 and 13 months, the peak pressures of Al/CuO nanothermite were 685.8 kPa, 626.3 kPa and 625.5 kPa, respectively. In addition to the ignition temperature, it was 775 ℃, 739 ℃ and 754 ℃, respectively. This result indicated that the ignition and combustion properties of Al/CuO nano-thermite are obviously reduced when stored for a long time, at room temperature.     

指挥自动化系统可生存性研究

可生存性是指当一个系统在受到攻击、出现错误或发生紧急事件时仍然能够完成其任务的一种能力.指挥自动化系统是现代战争中部队战斗力的倍增器.在信息化战争条件下,传统的安全策略将不能保证指挥自动化系统的生存能力.通过介绍可生存性思想,分析指挥自动化系统及子系统的特点和存在的问题,提出了利用可生存性设计指挥自动化系统的基本原则.