浅谈有线数据通信及其应用前景

介绍数据通信的构成原理、交换方式及其适用范围;有线数据通信的分类,并展望未来美好的应用前景。     

牵引变电所新型电能综合监测装置的研究

电能综合监测装置通过对牵引变电所的电压、电流进行同步采集、计算,确定电能和负荷统计参数,进而得出牵引变压器的容量利用状况和损耗。介绍了该装置的主要功能,技术参数和计算公式,并从提高变压器的容量利用率和充分利用主变寿命方面探讨了牵引变电所经济运行管理的可行性。     

客运决策支持系统数据仓库模型的研究与应用

铁路客运决策支持系统是铁路信息化的必然产物，本文结合客票系统和18点速报提供的数据源，进行了客运决策支持系统的数据模型设计，并研究设计出了一套数据仓库系统设计可借鉴的数据模型设计方法，运用这些方法解决了维表和事实表的关系识别，事实表存储以及如何捕捉数据变化等几个难题。     

决策支持物流管理信息系统的设计与开发

介绍了决策支持系统的概念及其内容，分析了在物流管理信息系统基础上实施决策支持系统的必要性和可行性，并针对库存问题研制了决策支持系统，研究了决策支持在物流企业中的实际应用．利用现代的信息分析技术，把决策支持系统应用于信息系统，将管理信息系统延伸为决策支持下的管理系统，为企业决策者提供决策支持，提高企业核心竞争力．     

大坡度斜井断面测量

介绍海南某工程大坡度斜井净空断面测量方法。通过数据采集,进行坐标转换,能够方便地计算出测点超欠挖。现场测量表明:该方法经济实用,能达到事半功倍的效果。     

基于Vague集和GIS的铁通运营决策支持系统

铁通运营决策支持系统的应用使铁通公司决策智能化,提高了决策的质量和效率.介绍了系统设计和功能结构,阐述了数据仓库技术、GIS技术在Vague集决策支持系统中的应用.该系统实现了数据库管理,问题分析,专家决策等功能.     

数据挖掘技术在乳化器故障诊断中的应用

决策树是一个类似于流程图的树结构,主要用途是提取分类规则,进行分类预测。该文针对乳化炸药生产过程中的乳化器维护面临的实际问题,提出了用决策树算法对反映设备状态属性的数据进行挖掘,发现故障数据中存在的规律,并以规则的形式表现出来,从而为乳化器的维护提供决策信息。结果表明,采用决策树方法所得出的规则是正确的,并能正确用于故障的分类工作。     

Seasonal variability of the Black Sea chlorophyll-a concentration

The optimal spectral decomposition (OSD) method is used to reconstruct seasonal variability of the Black Sea horizontally averaged chlorophyll-a concentration from data collected during the NATO SfP-971818 Black Sea Project in 1980–1995. During the reconstruction, quality control is conducted to reduce errors caused by measurement accuracy, sampling strategy, and irregular data distribution in space and time. A bi-modal structure with winter/spring (February–March) and fall (September–October) blooms is uniquely detected and accurately documented. The chlorophyll-a enriched zone rises to 15 m depth in winter and June, and deepens to 40 m in April and 35 m in August. The June rise of the chlorophyll-a enriched zone is accompanying by near-continuous reduction of upper layer maximum chlorophyll-a concentration.     

现行公路工程竣工资料归档管理办法存在的问题和解决办法探讨

公路工程竣工资料归档工作是工程建设与管理的重要内容,但由于现行管理办法尚有一些不合理之处和在认识上存在一些误区,导致在实践中,一方面造成资料规模过大,增加了管理成本;另一方面却降低了资料的档案属性和利用价值。本文拟从施工技术管理和档案管理两个专业角度,就如何提高在工程建设中资料收集工作的有效性,增加档案资料的档案价值方面,进行初步的探讨。     

Sequential data assimilation in an upwelling influenced estuary

We have evaluated the impact of assimilating chlorophyll, nitrate, phosphate, silicate and ammonium into a coupled 1D hydrodynamic ecosystem model (GOTM-ERSEM) in an upwelling influenced estuary. The assimilation method chosen is the Ensemble Kalman Filter (EnKF), which has been demonstrated to improve field estimates of key variables (chlorophyll, nutrients) for bulk algal bloom prediction. The 1D model has been set up for a central station inside the Ría de Vigo (Spain). Data from bi-weekly surveys are used to constrain the model. Temperature and salinity profiles are used to ensure the correct representation of the water structure through a relaxation scheme. Chlorophyll extracts and nutrients at three depths are assimilated sequentially during 1 year simulation (1991). The assimilation period includes episodes of active upwelling and downwelling. All five assimilated variables are successfully constrained and represent a large improvement on the reference simulation (without assimilation). Small divergences can be related to poorly resolved physical processes in the model. The assimilation was further evaluated by comparing observed biomass partitioning with model results. Diatoms accounted for the largest biomass update and the largest improvement in terms of percentage of variance explained (R²). This is particularly significant as they represent the 46% of the yearly integrated observed biomass of the planktonic autotrophs. Nonetheless the R² value was low for all phytoplankton groups. Bacteria and nanoflagellates showed an improvement with respect to their yearly Root Mean Square (RMS), while the other functional groups worsen or remained unaffected. Chlorophyll assimilation was responsible for most of the impact on the phytoplankton biomass with small contributions from the silicate. It had minor impact on the updates of nutrients which in turn corrected the state variables related to the detrital pool. In this current setting, combined assimilation of chlorophyll and nutrients is not sufficient to produce a skillful simulation of the phytoplankton succession.