基于K-means和SOM的水下传感器数据采集方法

随着海洋资源勘探和海洋污染物监控工作的开展，水文数据的监测和采集等已经成为重要的研究方向。其中，水下无线传感器网络在水文数据采集过程中起着举足轻重的作用。本文研究的是水下无线传感器二维监测网络模型中，传感器节点数据采集的问题，其设计方法是通过自组织映射（Self-organizing mapping，SOM）对传感器节点进行路径最优化处理，结合优化的路径图形和K-means算法找到路径内部聚合点，利用聚合点和传感器的节点得到传感器通信半径内的数据采集点，最后通过SOM得到水下机器人（Autonomous underwater vehicle，AUV）到各个数据采集点采集数据的最优路径。经过实验验证，在水下1 200 m×1 750 m范围内布置52个传感器节点的情景下，数据采集点相比于传感器节点路径规划采用相同的采集顺序得到的路径优化了6.7%；对数据采集点重新进行自组织路径规划得到的路径比传感器结点路径的最优解提高了12.2%。增加传感器节点的数量，其结果也大致相同，因此采用该方法可以提高水下机器人采集数据的效率。     

Emergence of collective changes in travel direction of starling flocks from individual birds' fluctuations

One of the most impressive features of moving animal groups is their ability to perform sudden coherent changes in travel direction. While this collective decision can be a response to an external alarm cue, directional switching can also emerge from the intrinsic fluctuations in individual behaviour. However, the cause and the mechanism by which such collective changes of direction occur are not fully understood yet. Here, we present an experimental study of spontaneous collective turns in natural flocks of starlings. We employ a recently developed tracking algorithm to reconstruct three-dimensional trajectories of each individual bird in the flock for the whole duration of a turning event. Our approach enables us to analyse changes in the individual behaviour of every group member and reveal the emergent dynamics of turning. We show that spontaneous turns start from individuals located at the elongated tips of the flocks, and then propagate through the group. We find that birds on the tips deviate from the mean direction of motion much more frequently than other individuals, indicating that persistent localized fluctuations are the crucial ingredient for triggering a collective directional change. Finally, we quantitatively verify that birds follow equal-radius paths during turning, the effects of which are a change of the flock''s orientation and a redistribution of individual locations in the group.     

Fractal properties of spectrum characteristics of electromagnetic radiation under failure of rocks and structural materials

The fractal characteristics of an electromagnetic radiation signal image in a frequency range are calculated. It is shown that the fractal dimension of time section of the signal can serve as a characteristic that the failure surface has formed. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 55–68, March–April, 2007.     

城市生态系统的生态调控研究

城市生态系统是生态系统中最为复杂的类型,借助于先进的科学理论对其进行分析,是城市生态系统研究的发展趋势。本文试图将当代科学前沿理论——自组织理论的观点应用于城市生态系统中,探究系统自组织演化的条件、动力和途径,以期从不同侧面来探索城市生态系统的可持续发展,促进城市生态系统的良性循环。     

路线选择行为的分支模型

本文提出了基于自组织理论的路线选择的模型,研究了存在实时交通信息条件下司机路线选择行为的演化规律,讨论了模型参数,分析了模型的稳定性,为宏观分析交通信息系统的效果提供了有益的思路和结论。     

建筑设计生成艺术的应用实验

介绍鹿特丹的KCAP和阿姆斯特丹的OAP工程团队以及苏黎士联邦理工学院的CAAD研究组运用生成技术合作完成的荷兰格罗宁根市火车站站前广场工程,探索生成艺术在建筑设计工程领域中应用的可行性及前景。     

Artist intermediaries in Berlin: cultural intermediation as an interscalar strategy of self-organizational survival

This paper argues that intermediation is both a valuable form of occupational self-organization for professional artists and a political act of embedding with socio-spatial ramifications at different local, urban, and global scales. A case study of events organized in Berlin by the interdisciplinary cultural centre Zentrum für Kunst und Urbanistik demonstrates how artists strategically practice intermediation as modes of autopoietic and dissipative self-organization and as an interscalar survival strategy. These artist intermediaries add improvisational flexibility to the state’s understanding of Verstetigung (sustainable anchoring that fosters a reliable relationship between urban policymakers and cultural producers) and challenge neoliberal urban development logics that instrumentalize creativity.     

离散元中破碎自组织对颗粒破碎影响研究

从数学领域的阿波罗填充法入手,建立了4种破碎自组织,并借助线性膨胀法保证破碎前后质量守恒。在此基础上,开展了不同破碎自组织的数值试验,研究了破碎自组织对级配演化以及材料的宏细观力学特性等的影响。结果表明:颗粒级配曲线的分形维数和颗粒间的平均应力随破碎自组织中颗粒数目增多而下降,而相对破碎率B_r和材料的压缩性随自组织中颗粒数目增多而增大。加载过程中的法向接触和接触力玫瑰图表明,自组织中颗粒数目愈多,材料的各向异性程度愈低,颗粒法向接触数目愈多,而法向接触力愈小。另外,配位数及接触力的概率密度也与破碎自组织存在密切联系。     

自组织与自组织城市

自组织理论和方法在当代城市地理学和规划理论的前沿领域有着非常重要而深刻的应用 ,这方面的研究工作已经有30多年的历史乃至更早。文章评介了自组织城市理论、模型和自组织城市规划思想与方法 ,解释了自组织概念的基本含义 ,分别介绍了自组织城市研究的 7个重要领域 :耗散城市、协同城市、混沌城市、分形城市、细胞城市、沙堆城市以及FACS和IRN城市 ,讨论了基于自组织研究的空间复杂性问题     

Lessons from a Minimal Genome: What Are the Essential Organizing Principles of a Cell Built from Scratch?

One of the primary challenges facing synthetic biology is reconstituting a living system from its component parts. A particularly difficult landmark is reconstituting a self-organizing system that can undergo autonomous chromosome compaction, segregation, and cell division. Here, we discuss how the syn3.0 minimal genome can inform us of the core self-organizing principles of a living cell and how these self-organizing processes can be built from the bottom up. The review underscores the importance of fundamental biology in rebuilding life from its molecular constituents.