雷达信号成形规律的样本体系描述方法

针对多功能雷达工作在搜索方式时,其工作模式的转换以及同一模式下的脉冲信号均有规律可循的工作特点,提出一种基于雷达信号成形规律的样本体系描述技术。该方法利用多功能雷达工作模式的转换规律和脉冲本身的时频域参数变化规律,建立搜索模式转换样本、脉冲样本图和样本脉冲的层级数学模型,对多功能雷达脉冲信号成形规律进行提取和准确描述。仿真实验表明,样本体系描述技术不仅能够提取其对应的复杂体制雷达工作模式和脉冲信号,而且对噪声环境具有较好的适应能力。     

Efficient synthesis of 4D antenna arrays using a bitwise evolutionary genetic algorithm

In this paper, a bitwise evolutionary genetic algorithm (GA) is proposed to synthesize the power patterns of 4D antenna arrays efficiently. Within the binary optimized time sequences of 4D antenna arrays, the genes of 1 and 0 represent switch‐on and switch‐off period of antennas, respectively. Gene retention probability, which relates to the fitness values of each individual in the whole group, is proposed to evaluate how good each gene is. With the proposed gene retention probability, the crossover operator in traditional GA is replaced with a new method to generate the next generation. The proposed algorithm is applied to the synthesis of 4D antenna arrays with binary optimized time sequences, and the performance of the proposed algorithm is compared with that of traditional GA on the condition of the same parameter settings. The comparison results show that bitwise evolutionary GA improves the optimization efficiency significantly, which reduces the computation time as much as 85% on average of the traditional GA with the same goal. Copyright © 2014 John Wiley & Sons, Ltd.     

The Difficulties of Designing Future Coastlines in the Face of Climate Change

This paper adopts two perspectives. The first is a framing process aimed at defining and examining the conditions for adopting adaptive coastal governance. The second applies to relevant themes of changing coastal policy, central to the testing of adaptive coastal governance, namely cooperative science, risk-sensitive planning, socially fair insurance cover and effective ways to design, finance and engage with local communities over actual coastal change. We illuminate both missions through case studies in North Norfolk (England) and Portugal, all notably affected by coastal change. In England and Portugal, there is a broad understanding and acceptance of the likely effects of climate change. This recognition encourages debates over risk-averse planning, the design of proactive insurance cover, creative relocation of endangered property and new ways of predicting and paying for coastal adjustment. Yet, moving from a basic willingness to engage with coastal change to actual practices of landscape adjustment through such policy shifts is proving very difficult. In this research, we find that coastal landscapes are lived experiences, resigned acceptances of inevitable change and hopeful imaginings. Coastal management institutions are not geared to resolving this incompatibility and this paper explains why.     

The development of corporate social responsibility in the Australian construction industry

In the Australian construction industry, large companies develop corporate social responsibility (CSR) in order to maintain an image of being a good corporate citizen. CSR relevant to the construction industry is defined including the following activities: moral obligation to be a good citizen; sustainability; reputation; relationship with employees and unions; relationship with suppliers and community representatives; and commitment to reporting on CSR. CSR is then examined through 85 interviews conducted with members of boards of directors, suppliers, employees, customers and community representatives of 17 large corporations. In order to be recognized as a socially responsible business, the corporations should: apply a corporate governance structure that takes into consideration working environment concerns; improve their sustainability, occupational health and safety measures, relationships with suppliers and commitment to local community protection and engagement.     

Commercial Gentrification and Entrepreneurial Governance in Shanghai: A Case Study of Taikang Road Creative Cluster

Commercial gentrification—based on the adaptive reuse of historic dwellings for upscale shopping, dining and culture—is emerging as a new model of neighbourhood regeneration in China. Through an analysis of Shanghai's urban restructuring and a case study of Taikang Road Creative Cluster, this article demonstrates that entrepreneurial local government is a key facilitator. Conscious of the synergistic value of restored urban heritage with conspicuous consumption, tourism and even the creative industries, local officials have utilised their urban planning authority to open up urban heritage to a host of gentrifiers including businesses, artists and creative firms. In terms of social outcomes, some local residents have capitalised on inflated property values and gained the opportunity to move out of poverty. Nevertheless, socially exclusive outcomes have also been evident, as commercialisation eroded the living environment of rural migrants and other poor residents.     

Self-cleaning and colour-preserving efficiency of photocatalytic concrete: case study of the Jubilee Church in Rome

ABSTRACT

The Jubilee Church in the south-eastern outskirts of Rome is one of the first buildings constructed with super white reinforced concrete with self-cleaning photocatalytic cement. However, 16 years after the opening of the building, the self-cleaning and colour-preserving properties arising from the titania particles (TiO2) within the concrete mix are not meeting the design requirements and the concrete is showing premature evidence of decay. While the form of the decay is affecting the appearance of the building and not its structural soundness, the ageing pattern of the building's components is resulting in a high maintenance cost, one not easily affordable within the ordinary budget supported by a small parish. This study comprises the first comprehensive step in understanding the causes of the accelerated ageing pattern of the concrete, highlighting methods to improve the long-term durability of the concrete and therefore reduce the cost of its maintenance. Moreover, this research offered the opportunity to test the durability and the effectiveness of the TiO₂ in the real conditions on an actual building featuring non-standard geometries. The findings highlight how the ageing pattern directly connects with the geometry of the building and inadequate consideration of the local weathering at the design stage.     

运河古镇传统空间格局的图解初探——以常州市孟城、万绥两镇为例

以常州市新北区孟城、万绥两座运河古镇为例,探寻古镇传统空间格局的解析方法。以点、线、面、自然基底四要素为切入点,从构成要素和组合方式两方面对比分析了在传统条件和现实状况下古镇空间构成要素的分布特征与组合方式之异同,以期了解古镇传统空间格局特质,并为日后的保护管控及规划提供依据。     

桩墙式挡土结构的变形模式及其识别

基坑挡土结构的侧向变形数据是反映基坑工程安全与环境控制的重要指标之一。由于现场地质条件与施工过程的复杂性,实际发生的挡土结构变形与设计计算结果在变形值大小及分布形态上存在差异。基于工程经验及挡土结构的受力变形原理,总结归纳了挡土结构典型的变形模式及其特征,在此基础上,基于贝叶斯概率准则实现对挡土结构实测变形的整体模式及局部模式识别。依此不仅可判明实际施工工况的变化或可能存在的工程缺陷,同时由于其可以提供非正常变形模式的预警,从而弥补了现行规范中仅以变形大小和速率为预警指标的不足,对于提高信息化施工的准确性和及时性具有重要意义。     

向心取类与人地合宜——基于传统思维方式的《园冶》“相地”篇析读

作为兴造的首要环节,"相地"篇在《园冶》全书中至为重要。文章从中国传统层次性的空间秩序认知出发,通过宅园与别墅园的区分,解读该篇六种用地的分类;并进一步在传统关联性思维背景下,分析计成对"地有异宜"和"人有异宜"的考量以及意境的营造与体验,尝试分析文本本身对"相地合宜"的表达与阐释,深入挖掘该篇蕴藏的设计内涵。     

Planning in the Ethno-culturally Diverse City: A Comment

This article examines how major retailers, in their attempts to secure sites for very large stores (over 7000 m2 sales area), have had to adopt new strategies in order to overcome resistance from local authority and central government retail planning policy. These strategies include recycling of old retail developments with ‘open A1 consent’, participation in urban regeneration projects and development or redevelopment of ‘district shopping centres’ in urban areas. Discussion of these strategies reveals weaknesses and inconsistencies in retail planning policy in the UK.