丽江-大理地区地壳稳定性评价

采用模糊数学综合评判法，对丽江-大理地区的地壳稳定性作定量评价，认为该区地壳稳定性可划分为三类，各亚类地壳稳定性不均一。     

A Review of: “Geographic Information Systems for Geoscientists—Modelling with GIS”

Distances from points to closest shorelines in a given direction are used, for example, in some models for estimating wave exposure. Such distances, also called fetch lengths, can be determined using standard geographic information systems. However, performance may be a problem if these distances are required for a great number of study points. Two new algorithms for determining fetch lengths for study points in the same directions are presented in this paper. It is assumed that the two‐dimensional map is stored in vector format, i.e. shorelines of islands and mainland are stored as polygons. The first algorithm works on a set of undirected line segments derived from the shoreline polygons. The other works on a raster representation of the map. The algorithm saves memory by postponing the rasterisation until necessary. Both of the new algorithms have superior efficiency to a previously reported algorithm when the number of study points is large.     

雷州半岛南部土壤肥力综合评价及空间变异

通过测定雷州半岛南部845个耕地土壤样品pH、有机质、全氮、有效磷、速效钾、碱解氮的含量,采用层次分析法确定各肥力评价指标权重,应用模糊数学法对该区域耕地土壤肥力进行综合评价,并利用ArcGIS 9.2软件对土壤肥力空间变异进行分析.结果表明:雷州半岛南部土壤有机质、全氮、有效磷、速效钾、碱解氮平均值分别为26.18 g/kg、1.48 g/kg 、34.63 mg/kg、158.57 mg/kg、133.17 mg/kg;土壤速效磷的变异系数最高,为103.14%,属强变异性,有机质、速效钾、碱解氮、全氮的变异系数属中等变异性,pH值的变异系数最小.土壤肥力总体水平处于中等偏低;从空间分布来看,土壤肥力中部高,东北、西南部相对较低     

浙江省气温空间分布的数学模型及其在植茶热量适宜带划分中的应用

本文根据浙江省除海岛县外的59个气象站站址的气温等资料,应用多元统计原理,建立了浙江省地面气温空间分布的数学模型、从而得到我省地面气温空间分布的递变规律性。据此,根据茶树对热量条件的要求,将我省划分为五个植茶热量适宜带,从而推演出我省各植茶热量适宜带的分布规律。     

军用车辆运动速度数学模型

本文以军事地形分析应用为背景,分析了决定军用(轮式、履带)车辆运动速度的主要因素;以动力平衡为基础,建立了各有关因素与运动速度之间的函数关系,给出了求解方法,并指出了实际运用时应注意的问题。试算表明,该方法计算结果与试验统计数据基本吻合。     

南海污损生物生态研究进展

污损生物的附着会降低航速增加燃料消耗,增大动力载荷效应,阻塞排水管道,影响水产养殖,给人类生产生活带来很大危害。本文综合叙述了南海污损生物的调查方法及群落结构特点,并对下一阶段的研究重点进行了探讨,以期为进一步的工作提供参考和依据。     

A review of: “National Transfer Format,Release 1.0, January, 1987.” By THE WORKING PARTY TO PRODUCE NATIONAL STANDARDS FOR THE TRANSFER OF NATIONAL DIGITAL MAP DATA. (Southampton: The NTF Secretariat,Ordnance Survey, 1987. [Pp. 191: appendices and looseleaf annex.]

Metonymically used location names (toponyms) refer to other, related entities and thus possess a meaning different from their literal, geographic sense. Metonymic uses are to be treated differently to improve the performance of geographic information retrieval (GIR). Statistics on toponym senses show that 75.06% of all location names are used in their literal sense, 17.05% are used metonymically, and 7.89% have a mixed sense. This article presents a method for disambiguating location names in texts between literal and metonymic senses, based on shallow features.

The evaluation of this method is two‐fold. First, we use a memory‐based learner (TiMBL) to train a classifier and determine standard evaluation measures such as F‐score and accuracy. The classifier achieved an F‐score of 0.842 and an accuracy of 0.846 for identifying toponym senses in a subset of the CoNLL (Conference on Natural Language Learning) data.

Second, we perform retrieval experiments based on the GeoCLEF data (newspaper article corpus and queries) from 2005 and 2006. We compare searching location names in a database index containing both their literal and metonymic senses with searching in an index containing their literal senses only. Evaluation results indicate that removing metonymic senses from the index yields a higher mean average precision (MAP) for GIR. In total, we observed a significant gain in MAP: an increase from 0.0704 to 0.0715 MAP for the GeoCLEF 2005 data, and an increase from 0.1944 to 0.2100 MAP for the GeoCLEF 2006 data.     

A rough set approach to the discovery of classification rules in spatial data

This paper proposes a novel rough set approach to discover classification rules in real‐valued spatial data in general and remotely sensed data in particular. A knowledge induction process is formulated to select optimal decision rules with a minimal set of features necessary and sufficient for a remote sensing classification task. The approach first converts a real‐valued or integer‐valued decision system into an interval‐valued information system. A knowledge induction procedure is then formulated to discover all classification rules hidden in the information system. Two real‐life applications are made to verify and substantiate the conceptual arguments. It demonstrates that the proposed approach can effectively discover in remotely sensed data the optimal spectral bands and optimal rule set for a classification task. It is also capable of unraveling critical spectral band(s) discerning certain classes. The framework paves the road for data mining in mixed spatial databases consisting of qualitative and quantitative data.     

数学形态学在二值数字图像断续线形目标恢复上的应用

特征提取中,由于地物特征的差异及其它因素的影响,提取的目标大多是非连续的,这将导致提取的目标与实际情况不符合,若不进行恢复,势必影响对目标性质的认识和应用。本文基于数学形态学方法,首先对二值图像中非连续的线性目标进行了分析和处理,然后对结构元素的选取和分解进行了阐述。最后的实验结果表明,该方法效果较好。     

Geomoney: An option on frost, going long on clouds

The paper adopts a cultural economy approach to explore the emergence of a market in so-called weather derivatives, referred to in the paper as a form of ‘geomoney’. These are specially designed financial products that allow firms to protect their profits against the impact of changing weather conditions. The paper approaches the emergence of this market, and the issues its growth raises, in three interlinked stages. Weather derivatives are located amongst the hybrid collective that is contemporary finance and are analysed through the conceptual apparatus afforded by a cultural economy approach to finance. The paper employs this analytical line to examine the assumptions and models that enable the weather to be turned into a risk and then be transported and traded within capital markets. Through specific examples of weather products together with a discussion of the International Finance Corporation’s recent involvement in this market, the paper suggests something of the ‘world making’ capabilities of finance theory and the politics of finance often hidden beneath the mathematical models. The paper concludes by highlighting not only the usefulness of a cultural economy of finance to geographers but, in light of the examples discussed, the need for cultural economy to recognise and to engage critically in its analysis the politics that such a conceptual approach to the making of financial markets exposes.