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171.
In recent years methods have been developed to extract the seaward landfast ice edge from series of remote sensing images, with most of them relying on incoherent change detection in optical, infrared, or radar amplitude imagery. While such approaches provide valuable results, some still lack the required level of robustness and all lack the ability to fully automate the detection and mapping of landfast ice over large areas and long time spans. This paper introduces an alternative approach to mapping landfast ice extent that is based on coherent processing of interferometric L-band Synthetic Aperture Radar (SAR) data. The approach is based on a combined interpretation of interferometric phase pattern and interferometric coherence images to extract the extent and stability of landfast ice. Due to the low complexity of the base imagery used for landfast ice extraction, significant improvements in automation and reduction of required manual interactions by operators can be achieved. A performance analysis shows that L-band interferometric SAR (InSAR) data enable the mapping of landfast ice with high robustness and accuracy for a wide range of environmental conditions. 相似文献
172.
Users expect applications to successfully cope with the expansion of information as necessitated by the continuous inclusion of novel types of content. Given that such content may originate from ‘not‐seen thus far’ data collections and/or data sources, the challenging issue is to achieve the return of investment on existing services, adapting to new information without changing existing business‐logic implementation. To address this need, we introduce DOLAR (Data Object Language And Runtime), a service‐neutral framework which virtualizes the information space to avoid invasive, time‐consuming, and expensive source‐code extensions that frequently break applications. Specifically, DOLAR automates the introduction of new business‐logic objects in terms of the proposed virtual ‘content objects’. Such user‐specified virtual objects align to storage artifacts and help realize uniform ‘store‐to‐user’ data flows atop heterogeneous sources, while offering the reverse ‘user‐to‐store’ flows with identical effectiveness and ease of use. In addition, the suggested virtual object composition schemes help decouple business logic from any content origin, storage and/or structural details, allowing applications to support novel types of items without modifying their service provisions. We expect that content‐rich applications will benefit from our approach and demonstrate how DOLAR has assisted in the cost‐effective development and gradual expansion of a production‐quality digital library. Experimentation shows that our approach imposes minimal overheads and DOLAR‐based applications scale as well as any underlying datastore(s). Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
173.
研究了一种基于SPI通信的便携式电子膨胀阀控制器设计.该设计采用主控制板和按键显示板两个独立单片机系统的架构,且两个单片机系统之间应用SPI通信进行实时数据交换.详细介绍了SPI通信技术以及Atmega16单片机的SPI通信接口,并给出该便携式电子膨胀阀控制器的SPI通信部分的软件流程图. 相似文献
174.
基于概念扩充的中文文本过滤模型 总被引:8,自引:0,他引:8
1 前言今天,以因特网为主体的信息高速公路仍在不断普及和发展,因特网上蕴涵的海量信息远远超过人们的想象,面对这样的信息汪洋大海,人们往往感到束手无策,无所适从,出现所谓的“信息过载”问题。如何帮助人们有效地选择和利用所感兴趣的信息,同时保证人们在信息选择方面的个人隐私权利?这已成为学术界和企业界所十分关注的焦点。因此,信息过滤技术应 相似文献
175.
176.
Chi‐Woo Kim Chang‐Oh Jeong Jean‐Ho Song Hyung‐Guel Kim 《Journal of the Society for Information Display》2001,9(3):139-143
Abstract— TFT‐LCD panels for notebook‐PC applications requires a thin and light form factor, low power consumption, and good display quality, whereas the desktop monitor has different requirements such as large panel size, wide viewing angle, high resolution, brightness, etc. However, for the fifth‐generation of mass production, current panel technologies have to improve in order to cope with these requirements. In this article, various approaches to the manufacturing technologies of next‐generation TFT‐LCDs are discussed. 相似文献
177.
基于概念的中文文本可视化表示机制 总被引:1,自引:0,他引:1
为了浏览因特网上日益增多的在线中文文本,本文给出了基于概念的中文文本可视化表示机制,以直观的方式组织和表示文本及文本集,其基本思想是:首先在概念扩充的基础上,进行文本分类,然后,利用本文提出的提出的文本特征抽取方法和摘要方法,获取广西类别、广西、广西正文的标记的信息,通过类别,文本、有选择地浏览文本。 相似文献
178.
中文文本过滤的信息分流机制 总被引:17,自引:2,他引:15
在文本过滤中信息分流是提高过滤效率的有力的手段,为此,提出了一种新的中文文本过滤的信息分流机制.其基本思路是在概念扩充基础上,将不同用户的信息需求组织为树状结构,使其共同的部分成为共享分支,依据提出的侧面相似度和侧面匹配率来实现文本与模板的定量匹配,减弱传统的布尔模型对文本与模板匹配的严格限制,也弥补向量空间模型单纯数量化的不足,更加全面地反映用户的信息需求,试验表明该机制能够明显地提高过滤效率。 相似文献
179.
180.
Simulations of extensional flow in microrheometric devices 总被引:1,自引:0,他引:1
Mónica S. N. Oliveira Lucy E. Rodd Gareth H. McKinley Manuel A. Alves 《Microfluidics and nanofluidics》2008,5(6):809-826
We present a detailed numerical study of the flow of a Newtonian fluid through microrheometric devices featuring a sudden
contraction–expansion. This flow configuration is typically used to generate extensional deformations and high strain rates.
The excess pressure drop resulting from the converging and diverging flow is an important dynamic measure to quantify if the
device is intended to be used as a microfluidic extensional rheometer. To explore this idea, we examine the effect of the
contraction length, aspect ratio and Reynolds number on the flow kinematics and resulting pressure field. Analysis of the
computed velocity and pressure fields show that, for typical experimental conditions used in microfluidic devices, the steady
flow is highly three-dimensional with open spiraling vortical structures in the stagnant corner regions. The numerical simulations
of the local kinematics and global pressure drop are in good agreement with experimental results. The device aspect ratio
is shown to have a strong impact on the flow and consequently on the excess pressure drop, which is quantified in terms of
the dimensionless Couette and Bagley correction factors. We suggest an approach for calculating the Bagley correction which
may be especially appropriate for planar microchannels.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献