基于时空自动机的CPS建模与验证     

赵文明  陈仪香  张敏 《科技通报》2015,(1)

为了描述信息物理融合系统(cyber-physical systems,CPS)的时空一致性,一种实时规范语言STe C已经提出[1],CPS的设计和实现能否满足时空一致性显得十分重要。文中对混成自动机进行了扩展,提出了具有位置驱动特点的时空自动机。文中提出了基于时空自动机的CPS建模与验证框架。在框架中,首先使用STe C语言对CPS进行了描述并使用时空自动机对CPS进行建模。文中采用的形式化验证方法为微分动态逻辑(differential dynamic logic,DL),其操作模型为HP(hybrid program)。利用DL可以将所建模型转换为对应的HP。结合得到的HP对验证的CPS属性进行规约,最后使用定理证明器Ke Ymaera对属性进行自动化验证。  相似文献   

A Strategy for the Management,Preservation, and Reutilization of Geographical Information Based on the Lifecycle of Geospatial Data: An Assessment and a Proposal Based on Experiences from Spain and Europe     

Maria C. Porcal-Gonzalo 《Journal of Map & Geography Libraries》2015,11(3):289-329

In recent years, there has been a growing recognition of the fact that the proper management of information has to include concern for its preservation and future re-use. This ambition is particularly significant for geospatial data. The primary aim of this article is to define the European and Spanish frameworks for the preservation and reutilization of geographical information, with the ultimate goal of proposing an articulated, lifecycle-based data management model. With this, the intent is to shed some light on a complex, difficult and ever-evolving subject.

The article is divided into two main parts. The first part begins with a conceptual justification for geospatial data management and continues by synthesizing the current normative and technological framework for the preservation and reutilization of geographical information. Within this context, the implementation of Spatial Data Infrastructures (SDI) in Spain is evaluated. The second part begins with a case study from Spain that aims to identify different agents and flows that influence the lifecycle of geographical data, as well as the strengths and weaknesses found in each stage of the process under examination. Finally, the foregoing ideas are used in order to propose a SDI-related system for the management of geographical information.  相似文献   

Action at an attentional distance: A study of children's reasoning about causes and effects involving spatial and attentional discontinuity     

Tina A. Grotzer  S. Lynneth Solis 《科学教学研究杂志》2015,52(7):1003-1030

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湖南省工业集聚的空间关联性研究     

陈赤平  罗运辉  张紫琴 《湖南师范大学社会科学学报》2015,(3):109-117

湖南省各市州的工业总产值之间在空间上存在相关性,工业发展水平相近的市域有显著的集聚特性,但不同地区集聚程度存在显著差异。长株潭是我省工业发展的核心增长极,也是工业发展的热点区域;湘南部分地区和湘西地区是全省工业发展的“凹地”,处于工业集聚的边缘地带;工业发展的冷点区则集中在西北的市州。湖南省未来工业空间集聚格局,应该以长株潭为核心集聚区域,以连接长株潭与四大次级增长圈的交通道路和经济成长带为轴线,逐步向周边拓展,从而形成圈层状工业空间集聚结构。  相似文献   

辽宁省第三产业重心与经济重心的变动及其关系     

关伟  曹佳宾 《辽宁师范大学学报(社会科学版)》2015,(2):181-187

运用区域重心的概念和计算方法,利用辽宁省14个地级市2000—2012年国内生产总值(GDP)、第三产业生产总值,计算出辽宁省各年第三产业重心、经济重心坐标及移动距离,分析出重心移动方向,定量地表示第三产业、经济区域差异的动态变化,从而对第三产业分布和经济分布的演变关系进行比较分析。结果表明:第三产业重心和经济重心位于辽宁省几何中心的东南面,第三产业分布和经济发展呈现不均衡性;第三产业重心、经济重心迁移方向基本一致,总体有缓慢向西南方向迁移的趋势,第三产业重心迁移的幅度大于经济重心,第三产业和经济的不协调性有所增长;第三产业重心、经济重心在经纬度上均呈现较高的正相关性,经济重心偏移与第三产业重心偏移的相互影响程度较高。  相似文献   

黑水靺鞨地理分布研究综述     

王禹浪  王俊铮 《哈尔滨学院学报》2015,(4)

黑水靺鞨是隋唐时期活跃于我国东北地区的一支重要的少数民族,曾与唐朝、渤海等政权发生过密切的联系,在隋唐东北亚世界中扮演着重要角色。自隋朝黑水靺鞨始见于文献开始,直至渤海国灭亡,它一直以强大的姿态存在于东北亚地区,是女真完颜部的直系祖先。学术界对黑水靺鞨地理分布进行了深入的研究,文章旨在对这一领域的研究成果予以梳理整合,归纳研究特点和不足。  相似文献   

需求不确定情况下沿海燃料油供应鲁棒优化     

刘炬  钟铭  黄梦思  陈江涛  张宇涵 《上海海事大学学报》2019,40(4):33-39

针对沿海地区燃料油供应问题,制定燃料油配送方案,设计配送航线和配送量使运输成本和库存成本最小,同时考虑需求不确定的情况,使需求发生一定变动时原方案依旧可行。与不考虑需求不确定的供应方案相比,使用鲁棒优化方法得到的结果可靠性更强,发生缺货的可能更小。由于需求不确定情况下存在的二次约束严重影响模型的求解效率,提出一种两阶段求解方法来分解问题,使求解效率得到明显提高。对于存在需求不确定情况的供应系统,决策者使用该鲁棒优化模型时,可以根据风险偏好并通过调整参数最大限度地提高供应方案的可靠性。  相似文献   

我国体育彩票销售额的空间异质性及影响因素分析          下载免费PDF全文

王成龙 《河北体育学院学报》2019,33(6):41-48

收集2013—2017年我国31个省份体育彩票销售额的面板数据和2017年各省份社会发展指标的相关数据，运用探索性空间数据分析方法（ESDA），对31个省份体育彩票销售额的空间异质性特征及影响因素进行研究。全局空间自相关分析结果表明，体育彩票销售额具有明显的空间聚集性，且呈显著的空间正相关性。经分析，发现31个省份体育彩票销售额不均衡，东部沿海省份的销售额高于西部省份，提出应重点关注西部地区的体育彩票事业发展。31个省份体育彩票销售呈现出以次冷区域为主，个别热点区域和次热区域相结合的特点，说明我国体育彩票销售的区域性寡占市场特征较明显，提出应加强省份间的沟通交流，促进各区域联动均衡发展。在影响因素方面，人均GDP、体育场地面积对体育彩票销售额具有显著性影响，其中人均GDP对南方的影响大于北方，体育场地面积对东北地区的影响大于西南地区，提出应进一步加大对体育场地建设的投入力度，以促进我国体育彩票事业的发展。  相似文献   

Spatial Planning and its Need for National and Regional Bibliographies of Grey Literature     

Christian Erlinger 《Cataloging & classification quarterly》2019,57(1):59-72

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Guiding Low Spatial Ability Individuals through Visual Cueing: The Dual Importance of Where and When to Look     

Victoria A. Roach  Graham M. Fraser  James H. Kryklywy  Derek G.V. Mitchell  Timothy D. Wilson 《Anatomical sciences education》2019,12(1):32-42

Research suggests that spatial ability may predict success in complex disciplines including anatomy, where mastery requires a firm understanding of the intricate relationships occurring along the course of veins, arteries, and nerves, as they traverse through and around bones, muscles, and organs. Debate exists on the malleability of spatial ability, and some suggest that spatial ability can be enhanced through training. It is hypothesized that spatial ability can be trained in low-performing individuals through visual guidance. To address this, training was completed through a visual guidance protocol. This protocol was based on eye-movement patterns of high-performing individuals, collected via eye-tracking as they completed an Electronic Mental Rotations Test (EMRT). The effects of guidance were evaluated using 33 individuals with low mental rotation ability, in a counterbalanced crossover design. Individuals were placed in one of two treatment groups (late or early guidance) and completed both a guided, and an unguided EMRT. A third group (no guidance/control) completed two unguided EMRTs. All groups demonstrated an increase in EMRT scores on their second test (P < 0.001); however, an interaction was observed between treatment and test iteration (P = 0.024). The effect of guidance on scores was contingent on when the guidance was applied. When guidance was applied early, scores were significantly greater than expected (P = 0.028). These findings suggest that by guiding individuals with low mental rotation ability “where” to look early in training, better search approaches may be adopted, yielding improvements in spatial reasoning scores. It is proposed that visual guidance may be applied in spatial fields, such as STEMM (science, technology, engineering, mathematics and medicine), surgery, and anatomy to improve student's interpretation of visual content. Anat Sci Educ. © 2018 American Association of Anatomists.  相似文献