张掖市甘州区1959~2009年间城市扩展分析

利用锁眼、MSS、TM影像和地形图及其他辅助数据,提取张掖市1959、1968、1977、1986、1997、2009共6个年份的城市建成区范围和面积,利用空间重心转移模型、扩展强度指数、扩展速度指数、紧凑度指数、面积变化、城市用地扩展系数等指标,分析了近50 a来城市土地利用扩张的空间变化特征。结果表明,50 a间张掖市城市建成区扩展5.71倍,其中1986年之前属于缓慢扩展阶段,1986年之后属于快速扩展阶段。在1959~1986的27 a间,建成区面积仅扩展258.42 hm²。1986~2009年期间,随着改革开放和西部大开发战略的实施,建成区面积增加了1 995.11 hm²,是前27 a的7.73倍。1959~1977年期间,城市重心偏移量小,1977~1986年期间,虽然城市扩展面积较小,但城市主要向西和西北方向扩展,重心开始向西北偏移,偏移量较大;1977~2009年期间,由于城市向东和东北方向扩展,城市重心开始向东和东北方向偏移,偏移量都很大,最大达到629.79 m。城市紧凑度在1959~1968年间急剧下降;在1968~1997年间逐渐趋于稳定后又略有下降,1997~2009年开始慢慢上升,该市后期土地的集约化以及城市基础设施和公共资源的利用效率有所提高。城市用地扩展系数在1959~1986年期间小于1.12,城市用地规模扩展不足(1977年前后比较特殊),1986~2009年期间,城市用地扩展系数大于1.12,城市用地规模扩展过快。     

夜间灯光影像探究北京市城市发展空间特征

北京市作为中国首都,城市化发展迅猛导致诸多"城市病"问题出现。为避免城市用地的盲目扩张,给北京市未来城市用地合理规划和区域可持续发展提供科学参考,利用1992—2013年DMSP-OLS夜间灯光数据提取北京市建成区,从城市扩展的时空尺度、城市重心识别及其转移规律、城市空间形态变化及城市内部发展差异等方面对城市发展的空间特征进行研究。结果表明,近20年来北京市建成区面积不断增大,且从中心城区向外环状圈层式扩展。1992—2013年,建成区面积扩大了878km~2,21年内扩大为原来的3倍,且向东北方向扩展面积最大。城市扩展主要集中在1996—2007年,扩展面积占总研究时段的92%。整个研究时段,北京市重心向东偏北28°方向移动,城市重心从东城区转移到朝阳区,转移距离为5 000.71m。各市辖区的发展水平逐年提高,发展水平差距逐年减小;北京市空间形态在外延式和内涵式扩展之间交替变化。     

基于夜间灯光的2000—2018年成渝地区城市化过程研究

成渝城市群正逐步成为我国西部经济发展的增长极,探索其城市化时空格局对区域协调发展具有指引作用。基于2000—2018年整合夜光遥感数据提取城市群多期建成区空间范围,运用夜光规模统计、标准椭圆、位序—规模法则以及空间自相关等指标、模型定量分析了成渝区域城市化时空过程。结果表明：①灯光与统计数据配合下的建成区提取多年平均误差为1.27%,重庆、成都和绵阳市提取验证效果好;②19年间成渝各城市夜光规模显著增长,整体累计增长5.6倍,2010年后成渝城市群灯光规模扩张速度显著;③区域内各城市的位序—规模（rank-size）由高位序城市集中发展转向区域协调均衡发展,中小城市均有不同程度的扩张;④城市群规模重心位于四川资阳市安岳县,重心移动整体上以东南方向为主,空间格局整体呈现以“成都—重庆”为轴线沿西北向东南演变,空间范围逐渐扩张,说明以重庆为主的东南都市圈的社会经济形势更显著,对城市群发展更具影响力;⑤成渝城市群扩展的空间集聚程度逐渐加强,冷热点格局整体呈现冷点区占比大,热点区占比低的特征,热点区主要出现在位于成都与重庆主城区及其周边城镇。研究揭示了成渝城市群均衡发展的特征及热点区域,可作为未来城市功能规划和投资决策的参考。     

基于多源遥感数据的陕西2000～2015年城市扩展研究北大核心CSCD

夜间灯光数据已成为监测城市发展进程及空间格局演变的重要依据。利用覆盖陕西省的2000、2005、2010年3期DMSP/OLS数据及2015年无云复合NPP/VIIRS数据,结合MODIS等多源遥感数据构建VANUI、EANTLI两种指数模型,识别并提取陕西省城市建成区面积,经过对比分析后,选取较为精确的EANTLI指数重建陕西省2000～2015年城市扩展进程,并对西安市城市扩展的细节特征进行探究。结果表明:EANTLI指数在城市建成区识别与提取方面较VANUI指数稳定;2000～2015年陕西省城市扩展的不均衡性较为突出,关中各地市城市建成区面积增长速率最快,陕北次之,陕南地区较为缓慢。陕西省城市扩展的主要特征是以各地市中心城市为核心,呈同心圆或扇形模式向外蔓延;西安市城市扩展具有明显的外延性特征,城市重心逐渐向西移动,城市建成区向西北、西南方向持续扩展。     

利用夜间灯光数据的武汉城市空间格局演化

鉴于夜间灯光数据在市级尺度精度不足等问题,提出了一种基于NDVI修正的阈值提取法。在此基础上,采用空间扩展模式分析、景观格局指数、重心迁移模型方法,系统性分析近16年武汉市城市扩张时空特征,以期为武汉未来城镇建设用地布局及相关政策制定提供决策依据。研究结果表明,基于NDVI修正的阈值提取法,可用于地级市建成区提取及城市扩展研究;武汉城市扩张模式表现为以主城区为中心的面状发展为主,点状城镇发展所占比例相对较小,主要受黄陂区、新洲区的牵引;城镇发展经历了高度破碎化时期之后不断趋于集约化发展,破碎度逐步减小;武汉建成区重心移动幅度越来越大,城市化过程总体处于较快发展状态。     

近70 a天津主城区城市土地利用/覆盖变化遥感监测与时空分析

城市扩展和城市土地不同地表覆盖组合对城市生态系统服务和人居环境质量产生重要的影响。基于历史地图、遥感图像和城市规划图等多源数据通过人工数字化解译、大数据运算和混合像元分解相结合的方法发展了城市地表覆盖/土地利用数据集,从而获取了天津城市1949～2018年不同时段城市扩展过程,实现了其内部结构城市不透水面和绿地空间像元组分的遥感制图,综合分析了1949年以来天津主城区城市阶段扩展速度、扩展强度及城市不透水面和绿地空间地表覆盖类型的时空变化特征,进而揭示了社会经济因素和政策因素对其影响。研究结果表明:天津主城区城市土地面积从1949年的49.15 km~2增长到了2015年的663.39 km~2。从时间变化来看,城市扩展经历了"加速—减速—加速—减速"4个阶段;城市扩展的方式呈现以主城区填充式、沿比邻交通干线的乡镇,呈现带状扩展规律;扩展伴随城市建成区内部绿地空间比率呈现增加的趋势,表明天津主城区城市生态绿化水平总体呈现提升的状况。     

基于GIS的西安市城镇建设用地扩展研究

基于1988年TM影像、2002年ETM影像和2007年TM影像提取了西安市主城区和远郊区城镇建设用地信息,利用GIS技术对三期城镇建设用地进行了叠加得到西安市城镇扩展数据。利用主要道路交通图和行政边界图对扩展数据进行裁切,得到了西安市绕城高速内和远郊区的城镇扩展信息。运用扩展强度指数、城镇建设用地相对变化率和分形维数等模型对西安市的城镇扩展进行了分析研究。研究结果表明,研究区内的城镇建设用地面积从1988年的151 796 493.8 m2增加到2007年的365 180 608.0 m2,总体扩展了2.4倍。其中主城区的扩展主要集中在二环与绕城高速之间,二环内的城镇建设用地面积扩展速度相对较慢;西安市的3个远郊区中长安区扩展倍数最大,在1988~2007年扩展了7.39倍,其次为临潼区和阎良区;1988~2002年西安市的主城区和远郊区的分形维数都呈增加的趋势,城市边缘形态趋于复杂,而2002~2007年分形维数呈减少的趋势。西安市远郊区的城镇建设用地相对变化率高于主城区,未来城市发展的格局逐渐呈现为主城区城镇扩展速度的相对放缓和远郊区的规模不断增大的趋势。     

基于GIS的西安市城镇建设用地扩展研究

基于1988年TM影像、2002年ETM影像和2007年TM影像提取了西安市主城区和远郊区城镇建设用地信息,利用GIS技术对三期城镇建设用地进行了叠加得到西安市城镇扩展数据.利用主要道路交通图和行政边界图对扩展数据进行裁切,得到了西安市绕城高速内和远郊区的城镇扩展信息.运用扩展强度指数、城镇建设用地相对变化率和分形维数等模型对西安市的城镇扩展进行了分析研究.研究结果表明,研究区内的城镇建设用地面积从1988年的151 796 493.8 m2增加到2007年的365180 608.0 m2,总体扩展了2.4倍.其中主城区的扩展主要集中在二环与绕城高速之间,二环内的城镇建设用地面积扩展速度相对较慢;西安市的3个远郊区中长安区扩展倍数最大,在1988～2007年扩展了7.39倍,其次为临潼区和阎良区;1988～2002年西安市的主城区和远郊区的分形维数都呈增加的趋势,城市边缘形态趋于复杂,而2002～2007年分形维数呈减少的趋势.西安市远郊区的城镇建设用地相对变化率高于主城区,未来城市发展的格局逐渐呈现为主城区城镇扩展速度的相对放缓和远郊区的规模不断增大的趋势.     

基于夜间灯光数据的重庆市城市扩张研究

城市化现象是区域经济发展的重要体现,其进程反映了该地区经济发展水平。重庆自1997年直辖以来,经济得到了高速发展,城市化水平也相应迅速提高,寻找一种直观、高效的城市化表达方法,从全局上正确把握直辖以来重庆市的城市化发展成果具有重大现实意义。通过统计数据比较法对夜间灯光数据逐年提取重庆市建成区范围,再根据提取结果构建城市重心模型,计算城镇扩张速度,建立夜间灯光指数。研究发现:重庆市城镇分布在空间上呈点状分布并向四周扩张;城市化水平差异明显,其他区县远落后于主城区;城市重心由渝中区逐渐转移至渝北区内;城市扩张保持较高速度。以此为重庆市城市规划和建设提供重要参考。     

基于RS和GIS的新城区建设对城市扩展的影响研究——以徐州市为例

基于1990年、2000年、2010年三年徐州影像图,利用Erdas软件进行图像处理和监督分类,利用矩阵分析和相关分析,分别从数量和空间方向分析了徐州城市的扩展规律以及新城区在城市扩展中起到的作用。研究表明:(1)徐州城市扩展迅速,城市建设用地增加迅速,且新城区的建设在城市建设用地数量上起到决定性作用。(2)徐州城市的扩展成"年轮效应"并且首先在交通干线上发展起来,新城区的建设,直接影响到城市的发展方向。(3)新城区建设对城市建筑用地的影响:①缓解老城区城市建筑用地压力;②扩大城市建筑用地规模;③改变城市结构,有助于城市的更新和城市区划的调整。     

Intuition,Computation, and Information

Bynum (Putting information first: Luciano Floridi and the philosophy of information. NY: Wiley-Blackwell, 2010) identifies Floridi’s focus in the philosophy of information (PI) on entities both as data structures and as information objects. One suggestion for examining the association between the former and the latter stems from Floridi’s Herbert A. Simon Lecture in Computing and Philosophy given at Carnegie Mellon University in 2001, open problems in the PI: the transduction or transception, and how we gain knowledge about the world as a complex, living, information environment. This paper addresses PI across a model of interoperating levels: perception (P)—intuition (N)—computation (C)—information (I), as factored by cognitive continuity (1), temporality (2), and constitution (3). How might we begin to characterize our experience of an abstract information object across such a matrix? Chudnoff’s rationalist distinctions between perception and intuition serve as a first rung of the ladder. Turing’s brief references to the utility of intuition, in an allied, rationalist-Cartesian sense, provide the next step up to computation. Floridi provides the final link from computation to information.     

Photos,time, navigation,visualization, recommendation and interactive TV: issues and contributions

In this editorial we first present the ACM Symposium on Applied Computing (SAC) and its Multimedia and Visualization (MMV) track. Next, we introduce the papers which were selected from the MMV track at the 2009 edition of SAC to present novel results in extended versions in this special issue.     

Exploring,confirming, and randomization tests

In the context of randomization tests, this paper discusses the roles of exploratory data analysis (EDA) and confirmatory data analysis (CDA) in geoscience research. It shows: (1) how the classical methods of statistical inference can be used in EDA with nonrandom samples of data, and (2) how much of the knowledge in the geosciences is derived from EDA. The paper gives a FORTRAN IV computer program, CLASSTEST, that performs a randomization test for a multivariate analysis of variance (MANOVA) design. CLASSTEST will be useful in goescience research apart from its use in illustrating EDA and CDA.     

Linear and synchrosqueezed time–frequency representations revisited: Overview,standards of use,resolution, reconstruction,concentration, and algorithms

Time–frequency representations (TFRs) of signals, such as the windowed Fourier transform (WFT), wavelet transform (WT) and their synchrosqueezed versions (SWFT, SWT), provide powerful analysis tools. Here we present a thorough review of these TFRs, summarizing all practically relevant aspects of their use, reconsidering some conventions and introducing new concepts and procedures to advance their applicability and value. Furthermore, a detailed numerical and theoretical study of three specific questions is provided, relevant to the application of these methods, namely: the effects of the window/wavelet parameters on the resultant TFR; the relative performance of different approaches for estimating parameters of the components present in the signal from its TFR; and the advantages/drawbacks of synchrosqueezing. In particular, we show that the higher concentration of the synchrosqueezed transforms does not seem to imply better resolution properties, so that the SWFT and SWT do not appear to provide any significant advantages over the original WFT and WT apart from a more visually appealing pictures. The algorithms and Matlab codes used in this work, e.g. those for calculating (S)WFT and (S)WT, are freely available for download.     

Cross-scalar satellite phenology from ground, Landsat, and MODIS data

Phenological records constructed from global mapping satellite platforms (e.g. AVHRR and MODIS) hold the potential to be valuable tools for monitoring vegetation response to global climate change. However, most satellite phenology products are not validated, and field checking coarse scale (≥ 500 m) data with confidence is a difficult endeavor. In this research, we compare phenology from Landsat (field scale, 30 m) to MODIS (500 m), and compare datasets derived from each instrument. Landsat and MODIS yield similar estimates of the start of greenness (r² = 0.60), although we find that a high degree of spatial phenological variability within coarser-scale MODIS pixels may be the cause of the remaining uncertainty. In addition, spatial variability is smoothed in MODIS, a potential source of error when comparing in situ or climate data to satellite phenology. We show that our method for deriving phenology from satellite data generates spatially coherent interannual phenology departures in MODIS data. We test these estimates from 2000 to 2005 against long-term records from Harvard Forest (Massachusetts) and Hubbard Brook (New Hampshire) Experimental Forests. MODIS successfully predicts 86% of the variance at Harvard forest and 70% of the variance at Hubbard Brook; the more extreme topography of the later is inferred to be a significant source of error. In both analyses, the satellite estimate is significantly dampened from the ground-based observations, suggesting systematic error (slopes of 0.56 and 0.63, respectively). The satellite data effectively estimates interannual phenology at two relatively simple deciduous forest sites and is internally consistent, even with changing spatial scale. We propose that continued analyses of interannual phenology will be an effective tool for monitoring native forest responses to global-scale climate variability.     

Structural Lines, TINs, and DEMs

The standard method of building compact triangulated surface approximations to terrain surfaces (TINs) from dense digital elevation models (DEMs) adds points to an initial sparse triangulation or removes points from a dense initial mesh. Instead, we find structural lines to act as the initial skeleton of the triangulation. These lines are based on local curvature of the surface, not on the flow of water. We build TINs from DEMs with points and structural lines. These experiments show that initializing the TIN with structural lines at the correct scale creates a TIN with fewer points given a particular approximation error. Structural lines are especially effective for small numbers of points and correspondingly rougher approximations. Received December 21, 1995; revised September 24, 1999.     

VLSI芯片的可测试性、可调试性、可制造性和可维护性设计

CMOS器件进入深亚微米阶段，VLSI集成电路（IC）继续向高集成度，高速度，低功耗发展，使得IC在制造、设计、封装，测试上都面临新的挑战，测试已从IC设计流程的后端移至前端，VLSI芯片可测试性设计已成为IC设计中必不可少的一部分，本文介绍近几年来VLSI芯片可测试性设计的趋势，提出广义可测试性设计（TDMS技术）概念，即可测试试性，可调试性，可制造性和可维护性设计，并对可调试性设计方法学和广义可测试性设计的系统化方法作了简单介绍。     

Mixed reality in education, entertainment, and training

Transferring research from the laboratory to mainstream applications requires the convergence of people, knowledge, and conventions from divergent disciplines. Solutions involve more than combining functional requirements and creative novelty. To transform technical capabilities of emerging mixed reality (MR) technology into the mainstream involves the integration and evolution of unproven systems. For example, real-world applications require complex scenarios (a content issue) involving an efficient iterative pipeline (a production issue) and driving the design of a story engine (a technical issue) that provides an adaptive experience with an after-action review process (a business issue). This article describes how a multi-disciplinary research team transformed core MR technology and methods into diverse urban terrain applications. These applications are used for military training and situational awareness, as well as for community learning to significantly increase the entertainment, educational, and satisfaction levels of existing experiences in public venues.     

Similarity,precedent and argument from analogy

In this paper, it is shown (1) that there are two schemes for argument from analogy that seem to be competitors but are not, (2) how one of them is based on a distinctive type of similarity premise, (3) how to analyze the notion of similarity using story schemes illustrated by some cases, (4) how arguments from precedent are based on arguments from analogy, and in many instances arguments from classification, and (5) that when similarity is defined by means of episode schemes, we can get a clearer idea of how it integrates with the use of argument from classification and argument from precedent in case-based reasoning by using a dialogue structure.     

Advanced technology of high-resolution radar: target detection,tracking, imaging,and recognition

Ship detection from synthetic aperture radar (SAR) imagery plays a significant role in global marine surveillance. However, a desirable performance is rarely achieved when detecting small and densely clustered ship targets, and this problem is difficult to solve. Recently, convolutional neural networks (CNNs) have shown strong detection power in computer vision and are flexible in complex background conditions, whereas traditional methods have limited ability. However, CNNs struggle to detect small targets and densely clustered ones that exist widely in many SAR images. To address this problem while preserving the good properties for complex background conditions, we develop a coupled CNN for small and densely clustered SAR ship detection. The proposed method mainly consists of two subnetworks: an exhaustive ship proposal network (ESPN) for ship-like region generation from multiple layers with multiple receptive fields, and an accurate ship discrimination network (ASDN) for false alarm elimination by referring to the context information of each proposal generated by ESPN. The motivation in ESPN is to generate as many ship proposals as possible, and in ASDN, the goal is to obtain the final results accurately. Experiments are evaluated on two data sets. One is collected from 60 wide-swath Sentinel-1 images and the other is from 20 GaoFen-3 (GF-3) images. Both data sets contain many ships that are small and densely clustered. The quantitative comparison results illustrate the clear improvements of the new method in terms of average precision (AP) and F1 score by 0.4028 and 0.3045 for the Sentinel-1 data set compared with the multi-step constant false alarm rate (CFAR-MS) method. The values are verified as 0.2033 and 0.1522 for the GF-3 data set. In addition, the new method is demonstrated to be more efficient than CFAR-MS.