Avoidance of crude-oil contaminated sediment by the Australian seastar, Patiriella exigua (Echinodermata: Asteroidea)

This study attempted to determine whether Patiriella exigua, an Australian seastar, could detect and/or avoid oiled sediment when given an equal choice of unoiled sediment. The sediment was spiked once to produce one of three concentrations of oiled sediment used in the test chambers versus unoiled sediment. Behavioral observations were repeated over a 32 day period to test the effects of aging the oiled sediment. Results show that Patiriella exigua was capable of detecting oiled sediment and/or an oiled environment. Seastars avoided oiled sediment, with significantly higher numbers choosing either to reside on the clean sediment (p<0.05) or to travel up the glass sides of the tanks (p<0.001). Avoidance of oiled sediment increased with increasing sediment oil concentrations. Aging the oiled sediment decreased the oil content of the sediment and increased the number of seastars able to inhabit it (p<0.001). A potential narcotic effect of exposure to oiled sediment was observed.     

SAR影像中海洋浮油膜特征分割的Level Set方法

介绍了一种全新的区域影像分割技术--基于迎风格式偏微分方程（PDE）的Level Set方法进行海洋浮油膜特征提取.在该方法中,海洋浮油膜特征表示为扩散界面,影像灰度的梯度决定了界面扩散的方向和强度.界面边缘在影像灰度差异动力和曲率流的共同作用下不断向外扩散,能够有效地克服尖锐突起和裂缝等,在特征边缘趋于稳定和光滑.同时,该方法对高噪声具有一定抑制作用,适用于低对比度高噪声图像,特别是SAR图象中特征提取.以不同地区ERS-2 SAR图像中海洋浮油膜提取为例,进行方法验证,同时对传统的影像分割技术进行对比.     

Space-time visualization and analysis in the Cancer Atlas Viewer

This article describes the Cancer Atlas Viewer: free, downloadable software for the exploration of United States cancer mortality data. We demonstrate the software by exploring spatio-temporal patterns in colon cancer mortality rates for African-American and white females and males in the southeastern United States over the period 1970–1995. We compare the results of two cluster statistics: the local Moran and the local G*, through time. Overall, the two statistics reach similar conclusions for most locations. Where they disagree reveals functional differences in the kinds of local spatial variation to which the statistics are sensitive and identifies some interesting patterns in the data. There are only two persistent clusters of colon cancer mortality through time, and these are clusters of low values.This project was funded by grant CA92669 from the National Cancer Institute to BioMedware, Inc. The perspectives stated in this article are those of the authors and do not necessarily represent the official views of the National Cancer Institute. Constructive criticism from Heidi Durbeck of BioMedware, Peter Rogerson of SUNY-Buffalo, and three anonymous reviewers helped us improve the interpretation and presentation of these results.     

利用矿物成分概率神经网络法进行矿床分类

为了进一步确定量化矿床模式是否令人满意，本文对利用矿物成分概率神经网络法进行矿床分类做了检验。典型类型矿床的矿石和蚀变矿物成分存在与否被用来训练神经网络。为了降低要考虑的矿物种类，只利用至少一类矿床中矿物区占２０％以上的那些矿物。这一限制的好处在于单个或很少出现的矿物不会影响到正确分类结果。概率神经网络在贝叶斯定理基础上能定量地提供令人信服的分类度量，并且相对地对异常值不敏感。以Ｐａｒｚｅｎ密度估     

GIS与ES的结合及其应用初探

本文探讨了地理信息系统（ＧＩＳ）与专家系统（ＥＳ）结合的必要性、结合的方法以及应用于城市区划管理的ＺＯＭＡＮ系统（ＩｎｔｅｇｒａｔｉｏｎｏｆＧＩＳ＆ＥＳｆｏｒＺｏｎｉｎｇＭａｎａｇｅｍｅｎｔ）的结构、功能与应用实例。     

基扩展SQL的GIS模糊查询的表达与实现

模糊查询通常包含模糊单词和３种算子－语气算子、模糊化算子和判定化算子。通过模糊集合论，可表示这些模糊概念。在此基础上，介绍了一种扩展ＳＱＬ表在模糊查询，并将其转化为标准ＳＱＬ加以实现的方法。     

亚马逊水下三角洲底部边界层的测量

亚马逊水下三角洲底部边界层的测量Ｄ．Ａ．Ｃａｃｃｈｉｏｎｅ等近底边界层为流体剪切为直接作用于悬浮物及底床表层沉积物以形成冲刷或沉积的地带．对水下三角洲生长及结构的动力过程的认识主要借助于分析近底边界层重要的物理及沉积参数来进行的．本文我们利用ＧＥＯＰ...