A NEW RECEPTOR MODEL:A DIRECT TRILINEAR DECOMPOSITION FOLLOWED BY A MATRIX RECONSTRUCTION

In many cases,monitoring data for ambient airborne particles can be organized in the form of a three-way data table with one way for chemical species,one for sampling periods and one for sites.A directtrilinear decomposition followed by a matrix reconstruction(DTDMR)is developed to analyze such adata table as a whole.The three-way data set is composed into three two-way matrices by a direct trilineardecomposition(DTD).The column vectors of each of the matrices are called‘source profiles’,‘emissionpatterns’and‘site coefficients’respectively.Particulate sources are identified by examining both theirsource profiles and emission patterns.After the sources have been identified,emission patterns and sitecoefficients are used to produce a three-way matrix that gives estimates of mass contributions of sourcesto the samples collected at every site in every period.By simulation study,not only has the method beenverified,but a good indicator has been found that shows the number of factors(i.e.sources)in thesystem.Unlike other receptor models,DTDMR does not require source profile data and does not involvetrial-and-error procedures.Since DTDMR identifies sources based on variations in two dimensions,it hasa higher potential to distinguish two sources that have similar chemical compositions.The DTDMRmodel has provided excellent results with simulated data and has been applied in a real world three-waydata set.     

A review of A Teacher's Handbook on Energy

Abstract

A Teacher's Handbook on Energy, prepared under the direction of the Governor's Energy Advisory Council in consultation with the Texas Education Agency, January 1977.     

地理研究者的地图空间认知过程

地理研究者的地图空间认知过程，经历了地图的感知觉阶段、心象形成阶段、心象记忆对比分析阶段和认知思维（提出问题、解决问题）阶段。其对地图的认知带有强烈的目的性，已有的心象地图（地理空间概念）对地图空间认知有重要的影响。知觉过程经历了先自上而下后自下而上的两个阶段，是两个阶段的有机结合；心象地图的形成过程是概括地物图形特点、抽取地物组成元素及其组织关系的过程；心象地图的记忆则是构成心象的元素和组织这些元素的关系分别编码储存的过程；认知思维是根据地理空间概念进行判断、推理的过程，是地理研究者认知地图空间的核心；心象地图（地理空间概念）则是认知思维的基础。