Cognitive radio resource allocation based on coupled chaotic genetic algorithm   总被引：1，自引：0，他引：1  

俎云霄  周杰  曾昶畅 《海洋学报(英文版)》2010,29(11)

A coupled chaotic genetic algorithm for cognitive radio resource allocation which is based on genetic algorithm and coupled Logistic map is proposed. A fitness function for cognitive radio resource allocation is provided. Simulations are conducted for cognitive radio resource allocation by using the coupled chaotic genetic algorithm, simple genetic algorithm and dynamic allocation algorithm respectively. The simulation results show that, compared with simple genetic and dynamic allocation algorithm, coupled chaotic genetic algorithm reduces the total transmission power and bit error rate in cognitive radio system, and has faster convergence speed.  相似文献   

出行认知约束下的最优路径规划方法     

张帅毅  李永树  刘刚 《测绘科学》2013,38(3)

基于城市交通与城市形态结构的密切关系,本文探讨了环形城市形态下的城市交通网模型,并提出了结合大众出行认知特征的城市交通最优路径规划方法。为检验本文方法的有效性,利用成都市路网数据对本方法与传统路径规划方法进行了对比实验,结果表明本文方法所规划路径更适应实际状况,可有效地降低时间消耗、较好地符合层次空间推理机制。  相似文献   

The fractal nature of maps and mapping     

Bin Jiang 《International journal of geographical information science》2013,27(1):159-174

A fractal can be simply understood as a set or pattern in which there are far more small things than large ones, for example, far more small geographic features than large ones on the earth surface, or far more large-scale maps than small-scale maps for a geographic region. This article attempts to argue and provide evidence for the fractal nature of maps and mapping. It is the underlying fractal structure of geographic features, either natural or man-made, that make reality mappable, large-scale maps generalizable, and cities imageable. The fractal nature is also what underlies the beauty of maps. After introducing some key fractal concepts such as recursion, self-similarity, scaling ratio, and scaling exponent, this article demonstrates that fractal thought is rooted in long-standing map-making practices such as series maps subdivision, visual hierarchy, and Töpfer’s radical law. Drawing on previous studies on head/tail breaks, mapping can be considered a head/tail breaks process; that is to divide things around an average, according to their geometric, topological and/or semantic properties, into the head (for those above the average) and the tail (for those below the average), and recursively continue the dividing process for the head for map generalization, statistical mapping, and cognitive mapping. Given the fractal nature of maps and mapping, cartography should be considered a perfect combination of science and art, and scaling must be formulated as a law of cartography or that of geography in general.  相似文献   

PERIODIC MARKETS: COMMENTS ON SPATIAL-TEMPORAL RELATIONSHIPS     

《The Professional geographer》2013,65(2):147-151

This work examines the use of an annually updated metropolitan data system as a tool for evaluating benign racial location policies during the first year of the Section 8 Existing Rent Supplement program. Case-study evidence shows that the rent supplement program (with benign locational policies) is ineffective in reducing the isolation faced by minority groups, and that the information used to monitor compliance of the program with benign locational policies lags badly behind the true state of affairs. As a result, new areas of racial concentration have been encouraged and augmented.  相似文献   

教学环境、认知语境、元语用意识与语用失误     

黎政  胡春华 《广东海洋大学学报》2005,25(2):142-146

国内一些学者虽已对语用失误的原因进行过相当多的剖析,中国学生作为学习外语的一个群体,在语用失误的原因上有着更深层的原因,即宏观上的中国外语教学环境、微观上的认知语境误导、元语用意识干扰。对语用失误的深层研究将有助于培养中国学生的语用能力和推动我国外语教学的发展。  相似文献   

空间认知模式及其应用   总被引：7，自引：1，他引：7  

鲁学军  秦承志  张洪岩  程维明 《遥感学报》2005,9(3):277-285

从对不同空间模型的对比与分析入手,结合空间认知行为、神经系统科学和认知心理学的有关研究成果,对空间认知模式进行了研究。研究表明,“空间”的一般表现形式分为感知空间、认知空间和符号空间3种,不同的空间表现形式具有不同的空间认知方式;根据空间认知方式的差异,空间认知模式包括空间特征感知、空间对象认知、空间格局认知3个层次,而空间特征、空间对象则是空间认知模式构成的两个基本单位。文章以大华北地区为实验区域,通过对该区域强震发生空间的格局分析,进一步阐述了空间认知模式及其应用。  相似文献   

Framework of Pattern Recognition Model Based on the Cognitive Psychology     

WANGShugen 《地球空间信息科学学报》2002,5(2):74-78

According to the fundamental theory of visual cognition mechanism and cognitive psychology,the visual pattern recognition model is introduced briefly.Three pattern recognition models,i.e.template-based matching model,prototype-based matching model and feature-based matching model are built and discussed separately.In addition,the influence of object background information and visual focus point to the result of pattern recognition is also discussed with the example of recognition for fuzzy letters and figures.  相似文献   

Exploiting Illusory Grid Lines for Object-Location Memory Performance in Urban Topographic Maps     

Frank Dickmann  Dennis Edler  Anne-Kathrin Bestgen  Lars Kuchinke 《The Cartographic journal》2017,54(3):242-253

In order to be successful in spatial orientation tasks, people need to recall locations and configurations of spatial objects from their memory. This understanding of geographic space often arises from experience with cartographic media representing topographic and topological information by graphic symbols. Learning spatial information from graphic media is influenced by different perception-based grouping effects distorting the accuracy of spatial object-positions and their relations. Such geometric inaccuracies can be softened by adding a grid layer, which regionalizes the map and can be used as an additional orientation pattern. This grid layer usually consists of solid lines and overlays semantic information. The present paper reports the results of two empirical studies on object-location memory (OLM) performance. In these studies, the amount of visual detail of the grid layer was reduced. By positioning the grid layer below specific urban topographic objects (study 1), the grid pattern was graphically interrupted. These interrupted grid lines were completed by cognitive completion mechanisms (illusory grid lines) described in the Gestalt principles of closure and continuation. The second experiment examined the maximum grid line gap that is closed by cognitive line completion and keeps an advantage for OLM (study 2).  相似文献   

Learning Spatial Information from Maps: Can Orientation-Specificity Be Overcome?*     

Alan M. MacEachren 《The Professional geographer》1992,44(4):431-443

Maps that facilitate learning and navigating through an environment will influence the form and content of cognitive representations developed of that environment. Cognitive representations derived from maps have been demonstrated to exhibit orientation-specificity, a bias toward the orientation at which the map was studied, while cognitive representations derived directly from the environment appear to be orientation-free. An experiment was conducted to test the hypothesis that multi-orientation map presentation can eliminate the usual orientation-specificity. Results support the hypothesis but suggest that elimination of orientation-specificity will come at the cost of decreased accuracy in the cognitive representation obtained and/or slower access to the stored information.  相似文献   

地图学技术发展中的几点理论思考     

孟丽秋 《测绘学院学报》2006,(2)

文中分析总结了地图表达形式、价值能力、评价标准、设计者和使用者相互关系以及符号认知规律等的历史演变,提出在当今的全球网络时代,地图学理论工作者和地图系统研发者有责任重新定义地图的范畴并采用可用性作为地图的评价标准。就地图科学的发展趋势而言,作者以为3维仿真虚拟地理环境的普及给地图学提供了新的生长点,而正在兴起的3维非仿真虚拟地理环境将进一步保持和发扬传统地图的科学价值并使可视化技术走向可视化学。  相似文献