渠道水文数据仓库的分析

水文资料整合已经成为未来水文单位进一步发展的必经之路,水文单位需要进一步的发展和提高,就需要进行数据整合.文章采用数据整合技术,针对渠道水文信息数据存在的海量、复杂、时空性等一系列特点,以数据仓库、数据挖掘、数据整合、基本单元数据等几个方面建立分析流程,建设成统一的数据集成平台.随着数据管理、数据分析等技术的完善,以数据整合技术为基础的水文信息综合数据库体系将走向实用化.     

切片工具在网页中的应用

切片工具是平面设计软件自带的一个平面图像切割工具,将美工效果图转换为网页效果图的一个重要的工具,在互联网高度发展的今天,平面设计软件与网页制作软件相结合,设计与制作网页已经成为主流。着重讲解切片工具的作用与优点、切割网页的原则,以及使用案例解释使用切片制作网页。     

基于DW的空军通信装备技术保障DSS的框架研究

针对空军通信装备技术保障存在能力不足、决策支持手段落后等现状,提出了基于数据仓库(data warehouse,DW)的空军通信装备技术保障决策支持系统(decision support system,DSS)并构建了其整体架构,完成了系统DW设计,建构了系统元数据和数据抽取、转换、加载(extract,transform,load,ETL)的ETL模型,最后简述了系统的开发过程。该系统能有效地将通信装备技术保障数据转化为科学的决策信息,提高空军通信装备技术保障的效能。     

基于数据仓库的城市规划决策支持系统的研究和应用

目前我国城市规划管理部门积累了大量数据资源,但传统数据处理方式很难将其有效转换为支持管理决策的信息。研究认为,数据仓库作为一门新兴技术,其应用于城市规划管理将有助于解决传统数据处理的瓶颈问题。本文提出了一种基于数据仓库的城市规划决策支持系统的设计方法和构造模型,通过该系统,可使管理部门对很多规划信息进行比对、整合并作出正确决策,从而进一步提高城市规划管理决策的科学性和规范性。     

基于数据仓库的装备体系数据建模方法

分析装备体系数据仓库使用的基本特点,提出装备体系数据仓库的总体框架和数据集市。建立以基础数据维、元数据维和模型维为基础的三维数据模型立方体结构,给出其结构之间的逻辑关系并进行形式化描述,提出一种“阶梯式”的元数据管理模式。通过一个模型运行的示例介绍模型计算的实现方法。     

知识管理与决策支持系统

知识管理是现代企业管理理论发展的新阶段,传统的信息管理手段面临严峻的考验,已无法满足知识管理的需求。本文分析了决策支持系统在知识管理中的地位和作用,提出了基于知识管理的决策支持系统模型,并且对实现这种系统的关键技术进行了分析和评价。     

Droplet size and morphology analyses of dry liquid

Dry water is a free-flowing powder consisting of numerous solid particle-stabilized water droplets with typical sizes and volumes of 10^?6–10^?4 m and 10^?3–10³ pL, respectively. We describe the first characterization of dry water stabilized with hydrophobic silica nanoparticles, by using laser diffraction droplet size distribution analysis. The water droplet dimensions were measured to be a few tens of micrometers in air, by using the laser diffraction method. These dimensions correspond well with measurements by both laser diffraction and optical microscopy methods for a Pickering-type water-in-n-dodecane emulsion prepared by dispersing dry water in n-dodecane. Optical microscopy confirmed that the dry water consisted of flocs of non-spherical water droplets, and the flocs ranged in size from a few tens of micrometers to a few millimeters in air. On the basis of these results, the flocs of water droplets were proposed to dissociate into individual water droplets under the air blast during droplet size measurement by the laser diffraction method. It was also confirmed that pressurizing the dry water between two glass slides led to encapsulated water leaking from the silica nanoparticle shells. This on-demand pressure-sensitive water leak phenomenon shows a possible usage of the dry waters as a material delivery carrier.     

一种UWB通信、测距系统的数据链路层协议设计

针对基于DW1000芯片方案,搭建室内定位、测距系统的场合,为UWB通信系统设计一种数据链路层协议。主要阐述了该协议的架构设计,包括数据链路层系统中节点的部署、各类合作对象之间的动态交互、对象内部的工作状态转换,并使用统一建模语言(UML)对系统进行具体描述。     

A methodology for the performance evaluation of an experimental desiccant cooling system

An experimental investigation was conducted in an open cycle desiccant cooling system (DCS) operating on the ventilation mode in the laboratory site [M. Yıldırım, An experimental investigation on heat and mass transfer in a desiccant cooling system, PhD thesis, Gaziantep University, Turkey (2002). [1]]. Although the operation of DCS is presumably affected by the design of primary components of rotary regenerator (RR) and desiccant wheel (DW) the methodology used in the analysis of experimental data is presented in this paper to set a different approach for the performance evaluation of similar systems.

The rotational speeds of RR and DW (N_RR and N_DW), air mass flow rate (m_a) in process and regeneration lines, and the regeneration temperature (T_R) were defined as operation parameters. Meanwhile coefficient of performance (COP) and cooling capacity (CC) of the system were called as the performance parameters. The system operation with a variety of experimental conditions resulted in an extensive data set covering the ranges of N_RR, N_DW, m_a and T_R as 5 rpm ≤ N_RR ≤ 20 rpm, 0.1 rpm ≤ N_DW ≤ 0.4 rpm, 0.05 kg/s ≤ m_a ≤ 0.139 kg/s and 60 °C ≤ T_R ≤ 90 °C, respectively. The interactive influence of the operation parameters was determined through the realization of the psychrometric cycle in deviation from an ideal cycle. A dimensional analysis based on a trial and error procedure was followed to determine the functional relationship of COP and CC.

The proposed correlations between COP and CC and the introduced system performance parameter (PP) were determined to be a sole function of m_a independent of N_RR, N_DW and T_R in their covered ranges.     

数据仓库技术在国土资源信息系统中的应用探讨

探讨了把数据仓库技术引入到国土资源信息系统中，建立国家国土资源信息系统网络的构想及实现方法。