电磁频谱空间认知新范式：频谱态势

电磁频谱已经成为信息时代不可或缺的国家战略资源,面对越来越复杂的电磁频谱环境所带来的重大挑战,电磁频谱空间研究对未来频谱共享、无线电秩序管理以及电磁频谱战有着重要意义。本文从频谱态势理论模型、广域频谱态势感知、动态频谱态势生成和频谱态势高效利用4个方面,综述了对电磁频谱空间认知基础理论和关键技术的研究现状,并指出将孤立、分散、静态的频谱数据整合成一个整体、动态、关联、可视的异构数据集合是频谱态势未来的发展方向,为未来移动通信系统提升动态频谱效率、无线电秩序管理中提高恶意用户检测概率与虚警概率性能、对抗条件下增强频谱效能比,提供理论与技术支撑。     

Investigating behavioural and computational approaches for defining imprecise regions

People often communicate with reference to informally agreed places, such as “the city centre”. However, views of the spatial extent of such areas may vary, resulting in imprecise regions. We compare perceptions of Sheffield’s City Centre from a street survey to extents derived from various web-based sources. Such automated approaches have advantages of speed, cost and repeatability. We show that footprints from web sources are often in concordance with models derived from more labour-intensive methods. Notable exceptions however were found with sources advertising or selling residential property. Agreement between sources was measured by aggregating them to identify locations of consensus.     

Learning relative directions between landmarks in a desktop virtual environment

This study presents two experiments that examine howindividuals learn relative directions betweenlandmarks in a desktop virtual environment. Subjectswere presented snapshot images of different virtualenvironments containing distinguishing landmarks anda road network. Following the presentation of eachvirtual environment, subjects were given a relativedirection test. The relative direction test involvedindicating the direction of hidden landmarks fromdifferent vantage points in the environment. Half ofthese vantage points were presented during thelearning phase, while the other half were novel.Results showed that subjects learned relativedirections between landmarks equally well when sceneswere presented in either a sequential or random order.Furthermore, viewing a configuration of landmarks ina desktop virtual environment from multipleperspectives produced a viewpoint dependentrepresentation in memory. Subjects had significantlygreater response times for new viewing perspectives,as compared to previously viewed scenes. Thisviewpoint dependent representation of the environmentpersisted despite learning under conditions ofspatio-temporal discontinuity and changes to anenvironmental frame of reference.     

The influence of object size on judgments of lateral separation

The size of a previously experienced object has a significant effect on depth judgments in visually sparse environments. The present research explored whether familiar object size also significantly influences judgments of lateral separation. Experiment 1 required participants to detect changes in lateral separation using a one-shot change detection paradigm with a closer/same/farther forced-choice response. Participants accurately detected changes in lateral separation, although concurrent changes in object size significantly reduced the accuracy of their judgments such that increases (or decreases) in object size caused a relative underestimation (or overestimation) of separation. Experiment 2 replicated these results using a distance reproduction methodology. These results indicate that familiar object size exhibits a significant effect on judgments of lateral separation.     

基于认知云的无人机群组信息对抗系统

基于认知云的无人机群组信息对抗系统由长航时、低成本的电子战无人机群组和云计算网络构成。侦察无人机负责有限范围内的信息侦收，云计算网络融合无人机群感知结果，生成广域信息态势，动态制定系统层对抗策略，调度攻击无人机实施电磁频谱压制或信息接入攻击，同时评估对抗效能，实现信息攻防闭环。无人机群组抵近工作，可显著降低载荷设计复杂度，实现小型化、低功耗与有效性的统一设计。     

Learning Spatial Localization: From Rat Studies to Computational Models of the Hippocampus

In his landmark article, Richard Morris (1981) introduced a set of rat experiments intended “to demonstrate that rats can rapidly learn to locate an object that they can never see, hear, or smell provided it remains in a fixed spatial location relative to distal room cues” (p. 239). These experimental studies have greatly impacted our understanding of rat spatial cognition. In this article, we address a spatial cognition model primarily based on hippocampus place cell computation where we extend the prior Barrera–Weitzenfeld model (2008) intended to allow navigation in mazes containing corridors. The current work extends beyond the limitations of corridors to enable navigation in open arenas where a rat may move in any direction at any time. The extended work reproduces Morris's rat experiments through virtual rats that search for a hidden platform using visual cues in a circular open maze analogous to the Morris water maze experiments. We show results with virtual rats comparing them to Morris's original studies with rats.     

论权利贫困的社会认知

权利贫困是指由于制度因素所造成的对社会部分人群在政治、经济、社会和文化权利等方面的享有不足的状态，它具有客观性与必发性以及社会性和普遍性的特点。人们对贫困的认识已从狭隘的收入（经济）视角逐步扩大到政治、文化、社会等层面。学者们从社会剥夺与社会排斥理论、能力贫困理论以及一些经典的公民权利理论得到启发，逐步形成了权利贫困的观念，这是在学术界层面形成的对权利贫困的社会认知。此外，政治家对贫困问题的关注以及媒体对贫困问题的宣传和报道，将推动权利贫困的社会认知不断加深。     

Development of Landmark Knowledge at Decision Points

Two experiments investigated how people develop different landmark knowledge at decision points. Participants learned a route in a virtual city once or five times. One distinctive landmark was placed at each intersection of the route. At test, participants were released at each intersection according to the learning order and were required to determine the turning direction. At each intersection, the landmark was removed (no landmark), correctly placed (one landmark), duplicated on the other side (two identical landmarks), or misplaced from another intersection (two different landmarks) to disrupt the landmark sequence. The results suggested that humans develop different landmark knowledge (landmark knowledge for guidance, landmark knowledge for place recognition and knowledge of landmark sequence) with different navigation experience.     

Is Memory for Routes Enhanced by an Environment's Richness in Visual Landmarks?

We tested the hypothesis that a route's memorability is dependent on the frequency with which people are exposed to visual landmarks. Undergraduates learned either a route through an urban area lacking visually salient features, or a route in a neighborhood with many shops and urban objects. They were then asked to recall the learned route in the form of route directions and sketch maps. The results showed higher recall performance for the richer environment. When presented with photographs depicting scenes along the route, participants exposed to the richer environment had higher recognition scores and shorter response times than the others. The data confirm the functional role of landmarks in route memory and wayfinding.     

以生命教育为依托完善高职院校学生管理工作

介绍生命教育的基本特征,分析高职学生大学时期的主要生命特点,提出以生命教育为依托,完善高职学院学生管理工作的方法。