基于时空临近重复效应的犯罪热点特征及成因分析——以北京市抢劫案件为例

时空临近重复效应是犯罪活动的一种重要时空特征。为深入研究犯罪热点的特征及其形成原因,论文以北京市内城六区2012—2014年抢劫案件为例,通过核密度估计、时空临近重复计算及定义时空临近重复案件链等方法分析了犯罪热点的案件构成,并从犯罪人因素和环境因素等方面对犯罪热点内的案件特征结构进行了分析。结果表明：北京市内城六区的抢劫案件存在有“a”“b”“c”三个主要的空间热点,并且热点内的大部分案件均具有显著的时空临近重复效应;其中热点“a”位于双井、劲松一带,热点“c”位于南四环大红门桥一带,且2个热点内案件的犯罪人特征在一致性程度上高于环境类特征,表明热点的形成源于犯罪人在热点区域内重复作案的可能性较大;而热点“b”位于东南三环的分钟寺地区,热点内案件的环境类特征在一致性程度上高于犯罪人特征,表明该热点的形成为不同犯罪人在热点区域内集中作案的可能性较高。研究对警务部门开展针对性的犯罪打击和防控有一定的支撑作用。     

京津冀城市群产业空间重构与优化调控

科学解析京津冀城市群产业空间重构不仅有助于深化产业空间演化相应理论,也是服务京津冀协同发展国家战略的必然要求。论文从全球价值链视角出发,基于社会经济统计数据与全国工业企业库数据,采用经校正的产业比重变动方法对京津冀城市群产业空间重构进行了解析,并据此提出优化调控对策。主要结论有：① 产业空间重构是推动城市群发育与成熟的重要动力,其中嵌入全球价值链并持续攀升是推动城市群高级化的基础动力,而内部产业空间重构则是完善产业合作网络、推动城市群一体化的重要途径,此外,资源环境承载力与全球化、郊区化的交互是形成双“C”字形空间格局的基础与支撑;② 在国际产业空间重构方面,目前天津市为承接核心,北京次之,其余城市发展则相对滞后;③ 在城市群内部产业空间重构方面,由北京—天津—唐山—沧州围成的内“C”字形范围是产业空间重构的核心区,不同类型产业表现出不同的驱动特征,其中纺织服装业表现为全球价值链主导下的市场驱动,化学产业表现为环境管制与水资源依赖的双重作用,钢铁产业表现为明显的政府主导,医药制造业则表现为全球价值链主导下的政府调控;④ 京津冀城市群的内“C”字形地区应侧重产业升级,外“C”字形地区则重点关注生态环境保护与产业转型,以内“C”引领外“C”,以外“C”保障内“C”,双“C”联动,以保障京津冀协同发展战略的顺利实现。     

多尺度视角下的产业价值链与空间升级研究框架与展望

改革开放以来,在出口导向的产业发展模式驱动下,中国积极加入全球化进程并快速实现产业升级。进入21世纪后,在面临成本上升和制度环境变化等诸多危机和挑战的情况下,中国制造业开始了新一轮的产业升级。这从根本上重塑了产业组织和空间结构,改变着中国制造业在地方、区域乃至全球出口市场中的角色功能和影响力。基于文献分析,论文将产业升级划分为价值链升级和空间升级2种模式,并分别从全球、国家、区域、地方、企业等多尺度视角下探讨了中国产业升级的机制及其影响,得出以下主要结论：① 价值链升级和空间升级现象相互依赖、相互作用,是产业升级的2个侧面,综合两者的分析框架能更全面地反映中国产业升级的现状;② 中国产业在升级模式上体现了复杂多样性,已有研究关注的产业升级模式较为单一,未来应更加关注中国产业升级路径和方式的非线性、复杂性和多元性特征;③ 中国产业升级是由全球、国家、区域、地方、企业等多重尺度力量相互耦合下共同驱动的,透过多元地理尺度融合的分析框架解读产业价值链升级和空间升级机制,才能更好地理解中国产业的发展和赶超之路。     

一种新型Semi-Spar式海上风机平台系泊系统优化分析

参考英国的Kincardine风机采用的新式的Semi-Spar概念,结合spar式基础和半潜式基础的特点,提出了一种新式海上浮式风机平台模型,并基于三维势流理论,利用AQWA软件进行水动力计算,验证新式平台可靠性。分析了在风、浪、流荷载联合作用下,锚链竖向夹角、系缆数量对风机浮式平台运动性能和系泊张力的影响,对系泊系统进行优化,并验证极端工况下的可靠性。结果证明风机平台水平运动和纵摇运动幅值较小,但垂荡幅值略大,而通过减小锚链竖向夹角可以控制平台运动响应幅值,增加系缆数量可以同时减小系泊张力大小。计算结果证明了新型Semi-Spar式海上风机平台可行性,为浮式风机平台及系泊系统的设计提供参考。     

A mini-review on the microbial continuum:consideration of a link between judicious consumption of a varied diet of macroalgae and human health and nutrition

As the primordial,prokaryotic inhabitants on Earth,microbial entities were responsible for significant influences on the pathways taken in the development of life as we know it.The manifestation of numerous pathologies in humans is considered to be intrinsically associated with microbial dysbiosis in the gut(i.e.a poorly balanced microbiota).Such adverse health conditions include obesity,chronic fatigue syndrome,cancer,cardiovascular issues,neurological disorders,colitis,irritable bowel syndrome(IBS),and rheumatoid arthritis.Endosymbiotic events at the single cell level took place billions of years ago,eventually leading to eukaryotes,photosynthesis,and multicellularity.Macroalgae(seaweeds)were amongst the first organisms to develop these characteristics.Microbes and macroalgae interacted in a pattern of co-evolution,a process that applies to most,if not all living organisms.It is recognized that the normal human microbiome consists of over a trillion microorganisms,including about 2000 commensal bacterial species typically stationed in the gut.Many of these live in the colon,where they function in the digestion of foods,releasing bio-available nutrients,bioactive molecules,and various metabolites.They mediate communication signals between the gut and the brain,and promote the normal development of immune function,metabolic activities,behaviour,and neurological stability.As very early humans foraged for food,some would have benefi tted from coastal diets,rich in seaweeds and associated microbes.Such diets would have consistently provided all the nutrients essential for survival and growth,and as such,could have conveyed competitive advantages and contributed to enhanced cognitive sophistication.This mini-review article highlights studies regarding the health benefits of dietary fibres and the production of short chain fatty acids(SCFA).Insights are off ered regarding the positive effects the inclusion of macroalgae into the standard,Western diet can deliver in terms of providing appropriate fodder for those microbial populations deemed beneficial to human health and wellness.     

Linked Boundary Functions: Examining the Role of ‘Research for Development’ Organizations in Integrating Levels of Resource Governance

Natural resource management practices such as community-based resource management (CBRM) are well-established bottom-up approaches to developing adaptive governance systems. Less is understood about how communities involved in such processes can attract top-down support without compromising their credibility or salience. We tested the usefulness of the linked boundary functions concept – boundary chains – for explaining the role of “research for development” (R4D) organizations in the integration of bottom-up community resource governance and top-down policy and legislative governance. We used the Australian Centre for Agricultural Research (ACIAR) in the Solomon Islands as a case study to probe the role of R4D organizations in this regard. The linked boundary functions concept proved useful in exploring the active functions of R4D organizations as actors that lend credibility, salience, and legitimacy to community-based governance initiatives. The concept of linked boundary functions or boundary chains can contribute to the current discussion in the complexity-aware theory of change and open new avenues for boundary management that enable the development of integrated resource governance in complex development contexts. This article contributes to the existing literature on the boundary spanning activities of R4D organizations.     

A map-matching algorithm dealing with sparse cellular fingerprint observations

ABSTRACT

The widespread availability of mobile communication makes mobile devices a resource for the collection of data about mobile infrastructures and user mobility. In these contexts, the problem of reconstructing the most likely trajectory of a device on the road network on the basis of the sequence of observed locations (map-matching problem) turns out to be particularly relevant. Different contributions have demonstrated that the reconstruction of the trajectory of a device with good accuracy is technically feasible even when only a sparse set of GNSS positions is available. In this paper, we face the problem of coping with sparse sequences of cellular fingerprints. Compared to GNSS positions, cellular fingerprints provide coarser spatial information, but they work even when a device is missing GNSS positions or is operating in an energy saving mode. We devise a new map-matching algorithm, that exploits the well-known Hidden Markov Model and Random Forests to successfully deal with noisy and sparse cellular observations. The performance of the proposed solution has been tested over a medium-sized Italian city urban environment by varying both the sampling of the observations and the density of the fingerprint map as well as by including some GPS positions into the sequence of fingerprint observations.     

连云港近岸海域环境演变与生态修复对策研究

近岸海域环境演变及其发展趋势与人类活动密切相关.近岸海域的环境保护与生态修复措施的选择要求综合考虑多种影响因素,作者以连云港近岸海域为研究对象,在对连云港近岸海域进行综合性生态环境调查的基础上,运用因果链分析法,阐述了社会经济发展因素与环境演变之间的关系,确定了影响近岸海域环境变化的主要因子,对造成这些因子变化的直接原因、间接原因、驱动因素和涉及主体进行了深入分析,并提出了生态修复对策措施.     

基于Freeman编码的遥感影像直角型房屋半自动提取方法研究

通过分析遥感影像中直角型房屋特点,本文提出一种新的房屋提取方法:利用Freeman编码推导出常见直角型房屋代码,使得每一种形状房屋都具有惟一编号,且编号不随房屋大小、方位及位置改变而改变,利用Hough变换提取房屋角点并剔除伪角点,最后利用模式匹配方法获得各个角点之间的连接关系。实验结果表明该方法具有较强的抗噪性,能有效提取影像中直角型房屋。     

一种基于优先级动态调整的802.11e MAC协议

针对802.11eMAC协议不能良好地处理不同类型业务的节点间的公平性问题,提出一种基于优先级动态调整的802.11eMAC协议(P-MAC)。该协议网络中接入业务根据优先级设置权重系数,通过自适应调整业务权重系数,使不同业务均能公平地接入网络,从而保障业务的公平性问题。仿真结果表明:P-MAC协议相比于802.11eMAC协议,低业务数据流接入信道的机会增大了8%,与此同时,整个网络的平均吞吐量并未有所下降。