地理信息系统GIS(Geographic Information System,GIS)是计算机和信息系统技术在地理科学中的运用、发展的产物,因此其发展不仅受到GIS应用和需求的推动,同时也受到计算机和信息科学技术的影响。随着计算机、网络、数据库等技术的发展...
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地理信息系统GIS(Geographic Information System,GIS)是计算机和信息系统技术在地理科学中的运用、发展的产物,因此其发展不仅受到GIS应用和需求的推动,同时也受到计算机和信息科学技术的影响。随着计算机、网络、数据库等技术的发展以及应用的不断深化,GIS技术的发展呈现出新的特点和趋势,基于互联网的WebGIS就是其中之一。WebGIS是将Web技术应用于GIS技术开发的产物,是一个交互式的、分布式的、动态的地理信息系统。WebGIS以其易用性、开放性、全球性等特性,广泛的应用于传统的国土、环境等政府管理领域,以及导航、抢险救灾、LBS(基于位置的服务)、城市设施管理等和人们生活息息相关的方面。WebGIS的兴起和发展的需要,众多的GIS厂家都发展了自己的商业WebGIS产品如ESRI公司的IMS产品系列、MapInfo公司的MapXtrme产品系列、SuperMap IS、Geo-Surf等。但商业WebGIS产品由于可扩展性较弱、价格普遍昂贵、数据和操作共享困难等不足,难以满足低成本和高定制性的需求。基于开源软件的WebGIS由于其灵活和低成本等特性越来越受到开发者和公司的重视,涌现出许多成熟的产品。互联网的发展和移动终端的普遍,涌现出许多社交平台和软件,如QQ、微信(WeChat)、BBS、博客(Blog)等。人们交流的需要每天会通过这些软件和平台记录和分享身边发生的事,产生大量的数据。通过网络爬虫对这些数据的获取和筛选可以获得许多人们分享的和位置相关的信息,并借助WebGIS系统实现可视化可以帮助居民了解身边发生的事,为人们的生活提供方便。本文基于***和开源技术对这样的WebGIS系统进行研究和开发。首先对Web和WebGIS的发展和应用状况进行讨论,其次介绍系统搭建的相关技术支持,网络爬虫、***、开源软件、系统的架构等,最后对系统进行详细的设计,通过网络爬虫对数据的获取以及系统功能的展示,实现了系统对多种数据源的显示、基本操作、Popup实现等功能。
This paper describes the development of a prototype speech-controlled cloud-based wheelchair platform. The control of the platform is implemented using a low-cost WebKit Speech API in the cloud. The description of the...
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This paper describes the development of a prototype speech-controlled cloud-based wheelchair platform. The control of the platform is implemented using a low-cost WebKit Speech API in the cloud. The description of the cloud-based wheelchair control system is provided. In addition to the voice control, a GUI is implemented, which works in a web browser as well as on mobile devices providing live video streaming. Development was done in two phases: first, a small, initial prototype was developed and, second, a full size prototype was build. The accuracy of the speech recognition system was estimated as ranging from approximately 60% to up to 97%, dependent on the speaker. The speech-controlled system latency was measured as well as the latency when the control is provided via touch on a so-called smart device. Measured latencies ranged from 0.4 s to 1.3 s. The platform was also clinically tested, providing promising results of cloud-based speech recognition for further implementation. The developed platform is based on a Quad Core ARM Mini PC GK802 running Ubuntu Linux and an Arduino UNO Microcontroller. Software development was done in JavaScript/ECMA Script, applying ***. (C) 2015 Elsevier B.V. All rights reserved.
Deprecation is used by developers to discourage the usage of certain features of a software system. Prior studies have focused on the deprecation of source code features, such as API methods. With the advent of softwa...
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Deprecation is used by developers to discourage the usage of certain features of a software system. Prior studies have focused on the deprecation of source code features, such as API methods. With the advent of software ecosystems, package managers started to allow developers to deprecate higher-level features, such as package releases. This study examines how the deprecation mechanism offered by the npm package manager is used to deprecate releases that are published in the ecosystem. We propose two research questions. In our first RQ, we examine how often package releases are deprecated in npm, ultimately revealing the importance of a deprecation mechanism to the package manager. We found that the proportion of packages that have at least one deprecated release is 3.7 percent and that 66 percent of such packages have deprecated all their releases, preventing client packages to migrate from a deprecated to a replacement release. Also, 31 percent of the partially deprecated packages do not have any replacement release. In addition, we investigate the content of the deprecation messages and identify five rationales behind the deprecation of releases, namely: withdrawal, supersession, defect, test, and incompatibility. In our second RQ, we examine how client packages adopt deprecated releases. We found that, at the time of our data collection, 27 percent of all client packages directly adopt at least one deprecated release and that 54 percent of all client packages transitively adopt at least one deprecated release. The direct adoption of deprecated releases is highly skewed, with the top 40 popular deprecated releases accounting for more than half of all deprecated releases adoption. As a discussion that derives from our findings, we highlight the rudimentary aspect of the deprecation mechanism employed by npm and recommend a set of improvements to this mechanism. These recommendations aim at supporting client packages in detecting deprecated releases, understanding
The purpose of the work is to provide high-quality study of foreign languages in the conditions of distance education. To achieve this goal it is necessary to perform the following tasks: to analyze and select technol...
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The purpose of the work is to provide high-quality study of foreign languages in the conditions of distance education. To achieve this goal it is necessary to perform the following tasks: to analyze and select technologies for the development of server and client part of the service;. determine the requirements for the service;design the service according to certain requirements;implement the service, using selected technologies;analyze the results..
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