The geography of crime fear: A pilot study exploring event-based perceptions of risk using mobile technology

The current pilot study explores whether mobile technology can be leveraged in survey research to gather meaningful context-dependent data on fear of crime and risk perception formation. A series of Ecological Momentary Assessments (EMAs) were administered to students enrolled at an Australian University (N = 20), using a smartphone application. Analysis of data collected from participants in their everyday activity spaces a) show strong internal consistency among multiple measures of crime fear; b) indicate that perceptual measures of social cohesion are significant predictors of victimisation worry; and c) support most hypothesised associations between concepts contained in contemporary models of crime fear. Unfortunately, some aspects of the pilot study design could not be implemented as planned, which have implications for future research. Specifically, we found that triggering participant's surveys based on their location (rather than time), produced data that was not conducive to robust place-based analysis. In spite of this limitation, we offer alternative means of measuring the effects of place on fear of crime using mobile devices.     

Large-scale vulnerability assessments for natural hazards

This article examines the process by which vulnerability analysis takes place at the state level for State Hazard Mitigation Plans, as required by the Disaster Mitigation Act of 2000. The methods developed by the Center for Hazards Research and Policy Development at the University of Louisville are described, followed by a brief discussion on issues and challenges. A key finding in this article is the need to understand the impact and role of vulnerability analysis on planning and policy-making at the state and local level, as it applies to the investment of funding and resources in hazard mitigation. Recommendations for policy as well as directions in future research are offered in conclusion.     

应用CGDPA评估中国大陆地区IMERG的降水估计精度

应用国家气象信息中心基于地面雨量计的逐日降水分析产品CGDPA (China Gauge-Based Daily Precipitation Analysis)为基准数据,采用定量和分类评分指标分析了2014年9月—2015年8月中国大陆地区全球降水观测GPM (Global Precipitation M easurement)多星集成降水产品IM ERG (Integrated M ulti-satellite Retrievals for GPM)的精度。结果表明:1) IMERG日平均降水量能够较好地反映我国降水量的空间分布特点(局部地区偏低),季节平均降水强度的空间分布与CGDPA具有较好的一致性(尤其中东部和南部)。2) IMERG与CGDPA日平均降水量的相关系数在大部分地区介于0. 2～0. 5,只有少数地区超过0. 6,局部地区甚至出现负相关。3) IM ERG在中国大陆东部的降水估计精度明显优于西部,但东部绝大部分地区IMERG日降水量比CGDPA偏低10%～30%,甚至更低。4) IMERG与CGDPA降水概率密度相差最大的是微量降雨,其次是中雨,其他降水强度则相差很小。5)各季节IMERG探测降水的准确率POD都比较低,空报率FAR则比较高,临界成功指数CSI也比较低。     

西藏加查地区某水电站坝址区隐伏断裂研究

该水电站坝址区位于Ⅱ、Ⅲ级阶地平台上,被第四系松散沉积物覆盖,为探明下面是否发育有隐伏断层,本文首先研究从区域构造变形规律和坝址区周边基岩断层发育特征出发,结合断层气(氡气和地气)测量技术发现13号测点氡气和地气均出现异常,因此判断该阶地下面发育有一条规模较小的隐伏断层,走向近东西向,倾角较陡,对该处工程稳定性影响不大。也为今后该地区的隐伏断裂研究提供借鉴意义。     

伽马能谱法测量水中226Ra最短平衡时间的确定

伽马(γ)能谱法测量水中226Ra,在制样过程中天然放射性核素衰变链遭到破坏,一般规定样品放射性平衡期为3～4周后测定。通过试验证明,样品天然放射性核素衰变链最终达到平衡的最短时间为11d,测量结果在允许误差范围内,满足测量精度。     

JSCORS系统在太湖底泥勘探测量中的应用

从分析JSCORS系统技术特点入手,阐述了JSCORS系统的使用流程,并以竺山湖及西沿岸区北段底泥勘探测量为例叙述了在此工程中的使用过程,从使用过程中体会到JSCORS的系统在勘探测量中的巨大作用,因其覆盖范围广、效率高、劳动强度底、使用简便等特点在勘探测量单位广泛推广,JSCORS系统的使用是对勘探测量技术的又一次提升。     

IMU/DGPS辅助车载CCD及激光扫描仪三维数据采集与建模

三维信息快速采集是真实场景建模与三维虚拟现实技术的关键。本文提出了一种基于激光扫描仪、线/面阵CCD相机及GPS与IMU等多种传感器融合的车载移动式数据快速采集系统。各传感器安置在车内稳定平台上并随车保持一致的运动姿态。通过对GPS和IMU数据进行卡尔曼(Kalman)滤波,可推测出整个系统及各传感器的位置和最佳姿态估计;从扫描仪点云数据可提取出街道场景中事物的三维几何信息;线阵CCD相机用于获取路面带状地物等线性特征;面阵CCD采集街道两侧面状纹理信息,从而快速获得城市目标的地理坐标和三维建模信息,由此可重建城市路面街道的三维真实场景。     

信息化水平的八种测算方法

20世纪 80年代以来 ,信息技术对人类文明的影响超过了其他任何高新技术 ,信息化正成为经济增长的重要驱动力。信息化水平的测算始于 2 0世纪 6 0年代 ,可以说一些理论模型或方法目前已比较成熟 ,不少测算早已被世界各国所采用     

Advances in Measurement Techniques and Statistics Features

Rain Drop Size Distribution (DSD) is one of the key parameters to micro physical process and macro dynamical structure of precipitation. It provides useful information for understanding the mechanisms of precipitation formation and development. Conventional measurement techniques include momentum method, flour method, filtering paper, raindrop camera and immersion method. In general, the techniques havelarge measurement error, heavy workload, and low efficiency. Innovation of disdrometer is a remarkable progress in DSD observation. To date, the major techniques are classified into impacting, optical and acoustic disdrometers, which are automated and more convenient and accurate. The impacting disdrometer transforms the momentum of raindrops into electric impulse, which are easy to operate and quality assured but with large errors for extremely large or small raindrops. The optical disdrometer measures rainfall diameter and its velocity in the same time, but cannot distinguish the particles passing through sampling area simultaneously. The acoustic disdrometer determines DSD from the raindrop impacts on water body with a high temporal resolution but easily affected by wind. In addition, the Doppler can provide DSD with polarimetric techniques for large area while it is affected by updrafts, downdrafts and horizontal winds.DSD has meteorological features, which can be described with the Marshall Palmer (M-P), the Gamma, the lognormal or the normalized models. The M P model is suitable for steady rainfall, usually used for weak and moderate rainfall. The gamma model is proposed for DSD at high rain rate. The lognormal model is widely applied for cloud droplet analysis, but not appropriate for DSD with a broad spectrum. The normalized model is free of assumptions about the shape of the DSD. For practical application, statistical comparison is necessary for selection of a most suitable model. Meteorologically, convective rain has a relatively narrow and smooth DSD spectrum usually described by the M P model. Stratiform rain has a broad DSD spectrum described with the Gamma model. Stratocumulus mixed rain has relatively large drop diameter but small mean size usually described by the Gamma model. The continent rainfall is altitude dependent and it differs from the maritime cloud rainfalls in terms of rain rate and drop diameter. Overall, the meteorological features are useful to improve our understanding of precipitation formation but also important to development of precipitation retrieval techniques with a high accuracy.