地理标记语言的分组密码算法加密     

张立朝 《测绘科学》2017,42(2)

针对地理标记语言面向数据、可理解性等特点带来的信息安全隐患,该文从安全性的角度对地理标记语言文档加密进行分析,进而提出了一种地理标记语言文档的加密与签名相结合的安全加密方案,以解决地理标记语言文档在描述、存储以及传输过程中的安全问题。该方案首先使用密钥分发协议将密钥分发给通信双方,然后使用高级加密标准算法对文档加密,同时使用RSA算法对文档进行数字签名,进而实现地理标记语言文档高安全性加密。最后,对该方案进行安全性测试,结果表明该方案具有较好的安全性能和实现效率。  相似文献   

Personalized sightseeing tours: a model for visits in art museums     

Mayeul Mathias  Fen Zhou  Juan-Manuel Torres-Moreno  Didier Josselin  Marie-Sylvie Poli  Andréa Carneiro Linhares 《International journal of geographical information science》2017,31(3):591-616

This article describes a method to provide adapted visit tours in art museums according to the preferences expressed by the visitor and exhibits prestige. It is based on a dual approach with, on the one hand an automatic textual analysis of the official information available online (labels of exhibits) that allows to rank the exhibit attractiveness for a standard museum visitor. On the other hand, individual preferences are also taken into account to adapt the visit according to the personal cultural awareness of the visitor. We use operations research to solve a routing optimization problem, aiming at finding a visit tour with time constraints and maximization of the visitor satisfaction. Depending on the instance size and the problem scale, an integer linear programming (ILP) model and a greedy algorithm are proposed to recommend personalized visit tours and applied on two museums: ‘Musée de l’Orangerie’ in Paris and ‘National Gallery’ in London. The obtained results show that it is possible to recommend a good tour to visitors of an art museum by taking into account the common prestige of the exhibits and the individual interests, joining automatic text summarization and routing optimization in a limited geographical space.  相似文献   

基于径流形成原理的若干洪水预报理论述评          下载免费PDF全文

芮孝芳 《水科学进展》1992,3(3):233-240

对基于径流形成原理的洪水预报理论的近代研究成就作了较为系统的述评,并对其未来的发展作了一定的预示.  相似文献   

《京都议定书》缔约国履约相关状况及其驱动因素初步分析     

段晓男  曲建升  曾静静  刘莉娜 《世界地理研究》2016,(4):8-16

基于《联合国气候变化框架公约》和国际能源署的相关数据,评估了《京都议定书》缔约国温室气体减排方面的进展情况。研究发现,受金融危机等经济活动的影响,2008年~2011年期间各国温室气体排放量呈现动态变化的趋势。从国别排放看,伞形国家的碳排放量自1990年始,总体上呈增加的趋势,实现减排目标基本无望;欧盟国家整体完成了8%的减排目标,但各个国家完成情况不尽相同;经济转型国家减排幅度最大。通过能源利用强度和碳排放强度两个指标分析减排力度较大国家的排放轨迹,发现欧盟国家主要通过能源结构的调整(表现为煤炭比重下降和天然气比重上升)和外贸转移排放实现排放强度的降低,而经济转型国家的排放变化主要缘于其经济社会结构的变化。总体来看,缔约国的能源消费结构和利用方式基本稳定,能源利用强度与碳排放强度降低趋缓,在现有能源消费结构下减排潜力有限。  相似文献   

GPS接收机与PC机间串口通信的实现   总被引：8，自引：1，他引：8  

公丕波  郝金明  朱伟刚 《海洋测绘》2005,25(3):35-37,41

简要介绍了当前流行的几种串口通信程序开发模式以及GPS接收机广泛采用的NMEA0183通信协议，设计了串口通信类CSerialPortGPS，该类能够实现GPS接收机与Pc机问的串口通信，并且能够对遵循NMEA0183协议的GPS数据进行数据校验和数据提取，并成功地将该类应用到了车载定位导航系统的开发中。  相似文献   

一种工业计算机局部网络通信协议     

游华 《中国海洋大学学报(自然科学版)》1994,(Z2)

介绍了一种用于工业现场的计算机局部网络通信协议．详细介绍了网络的硬件结构和与之相配合的软件设计．同时，对其中关键技术如介质存取控制方式，数据的ＤＭＡ存取，缓冲区的分配与管理等作了重点说明．  相似文献   

A spatially distributed Clark’s unit hydrograph based hybrid hydrologic model (Distributed-Clark)     

Younghyun Cho  Venkatesh M. Merwade 《水文科学杂志》2013,58(10):1519-1539

ABSTRACT

A hybrid hydrologic model (Distributed-Clark), which is a lumped conceptual and distributed feature model, was developed based on the combined concept of Clark’s unit hydrograph and its spatial decomposition methods, incorporating refined spatially variable flow dynamics to implement hydrological simulation for spatially distributed rainfall–runoff flow. In Distributed-Clark, the Soil Conservation Service (SCS) curve number method is utilized to estimate spatially distributed runoff depth and a set of separated unit hydrographs is used for runoff routing to obtain a direct runoff flow hydrograph. Case studies (four watersheds in the central part of the USA) using spatially distributed (Thiessen polygon-based) rainfall data of storm events were used to evaluate the model performance. Results demonstrate relatively good fit to observed streamflow, with a Nash-Sutcliffe efficiency (E_NS) of 0.84 and coefficient of determination (R²) of 0.86, as well as a better fit in comparison with outputs of spatially averaged rainfall data simulations for two models including HEC-HMS.  相似文献   

Geospatially based distributed rainfall‐runoff modelling for simulation of internal and outlet responses in a semi‐forested lower Himalayan watershed     

RAAJ Ramsankaran  U. C. Kothyari  S. K. Ghosh  A. Malcherek  K. Murugesan 《水文研究》2012,26(9):1405-1426

This study presents a Geographic Information System (GIS)‐based distributed rainfall‐runoff model for simulating surface flows in small to large watersheds during isolated storm events. The model takes into account the amount of interception storage to be filled using a modified Merriam ( 1960 ) approach before estimating infiltration by the Smith and Parlange ( 1978 ) method. The mechanics of overland and channel flow are modelled by the kinematic wave approximation of the Saint Venant equations which are then numerically solved by the weighted four‐point implicit finite difference method. In this modelling the watershed was discretized into overland planes and channels using the algorithms proposed by Garbrecht and Martz ( 1999 ). The model code was first validated by comparing the model output with an analytical solution for a hypothetical plane. Then the model was tested in a medium‐sized semi‐forested watershed of Pathri Rao located in the Shivalik ranges of the Garhwal Himalayas, India. Initially, a local sensitivity analysis was performed to identify the parameters to which the model outputs like runoff volume, peak flow and time to peak flow are sensitive. Before going for model validation, calibration was performed using the Ordered‐Physics‐based Parameter Adjustment (OPPA) method. The proposed Physically Based Distributed (PBD) model was then evaluated both at the watershed outlet as well as at the internal gauging station, making this study a first of its kind in Indian watersheds. The results of performance evaluation indicate that the model has simulated the runoff hydrographs reasonably well within the watershed as well as at the watershed outlet with the same set of calibrated parameters. The model also simulates, realistically, the temporal variation of the spatial distribution of runoff over the watershed and the same has been illustrated graphically. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

PXE协议和Ghost工具在机房管理中的应用     

蔺冰 《成都信息工程学院学报》2007,22(3):327-329

为保证计算机房的软件系统使用率,利用3Com公司的DABS、Syrnantec公司的Ghost、Microsoft公司的windows Server等提供的软件、工具及服务,完成基于PXE协议网络启动和Ghost多播方式对计算机的软件系统克隆.该应用可以方便、快捷、简单的进行计算机房的软件批量管理.  相似文献   

一种基于非曼哈顿结构的Over-The-Cell布线算法研究     

许飞  汤银英  虞厥邦 《成都信息工程学院学报》2007,22(1):55-59

提出了一种基于非曼哈顿结构的单元上（Over-The-Cell，OTC）布线算法。算法第一次在单元上布线中采用非曼哈顿布线结构，并根据算法特点提出了线网和边相关系数的概念。实践证明，得益于单元区线网选择时对线网和边相关系数的应用，算法和传统标准单元详细布线算法相比，可以进一步降低通道高度和减少通孔数量。  相似文献