共查询到20条相似文献，搜索用时 234 毫秒
1.
Kirat Kamal Sampang Rai 《湿地科学》2006,4(2):87-90
Traditional culture bears a dynamic,cosmologi-cal vision in the wetland ecology and its biodiversityconservation in Nepal.The role of culture and rela-tionship in wetland biodiversity protection and wiseuse has not well been documented yet.Wetlands likeri… 相似文献
2.
I.MesozoicEraVolcanicAchvityDlepre-Tertlalyl11etal11olphicbase111entisOnlyexposedalongtheeastemflankoftheBackboneRangeoftl1eCentraIRangeinTaiwan(Figurel).Overlpngthebasen1e11t,tl1estratumofTertiarytoQuaten1alysysten11sexposed(Flgure2).Deposltlonofthepre-TertlaryrocksprobablybopninPen1llanperiodandextendedintoMesozoic.Theserockswerelatertectonizedandlnotal1lorPhosedinlateMesozoictil11earldtl1el11aJororogenic111ovelnentisnamedYenshanlllovelnent(t1ieNanaoorogenylnTaiwan).A:lthe111eta11… 相似文献
3.
STANLEY N.DEMING JOHN A.PALASOTA JOSEPHINE M.PALASOTA Department of Chemistry University of Houston Calhoun Ro Houston TX - U.S.A. 《地理学报(英文版)》1991,(3)
Chemometrics is defined as the application of mathematical and statistical methods to chemical systems.Systems theory is seen to be useful for organizing and categorizing the inputs to and outputs fromchemical systems.Advances in measurement science in the 1950s and 1960s,particularly in analyticalchemistry,created a need for a multivariate approach to data analysis.Early chemometrics emphasizedthe use of structure-finding methods for existing data sets.In many instances,data sets can be obtainedfrom designed experiments.Such data sets are more likely to contain the desired information and the datacan usually be acquired at less cost.Renewed interest in statistical process control will provide many new,more robust data sets in the future. 相似文献
4.
Several multivariate methods are now available for the calibration of second-order or hyphenatedinstruments(e.g.GC/MS).When applied to bilinear data,it has been shown that calibration can beperformed in the presence of unknown interferences-a significant advantage over first-order calibration.In this paper,non-bilinear rank annihilation(NBRA),a method which has the potential of handling,second-order non-bi-linear data,is studied through theoretical analysis and computer simulation.It isfound that the second-order advantage can be carried over to non-bilinear data if a property defined asnet analyte rank(NAR)holds for the analyte of interest.The net analyte signal(NAS)is definedaccordingly for second-order calibration and the analogy to and difference from lower-order calibrationare discussed.With NAS,some analytical figures of merit such as signal-to noise ratio,selectivity,sensitivity and limit of determination can be calculated for second order calibration.An application toMS/MS data is also given. 相似文献
6.
《The Professional geographer》2013,65(3):288-295
Analyses of the geography of British elections have typically stressed the continuity in patterns of party support. This paper challenges that conclusion. Employing an alternative method of analysis, it identifies significant regional trends in the Conservative and Labour vote between 1950 and 1983. Pro-Labour trends in Scotland and Northwest England are contrasted with secular changes favoring the Conservatives in non-metropolitan Southern England. These long-term trends have not been associated with growing regional polarization in party support. While the findings are specific to Britain, the method of assessing electoral change might be usefully applied to patterns in other countries. 相似文献
7.
HANNAN RASMUSSEN RHODES DONALD E.MYERS Department of Applied Mathematics University of Arizon Tucson AZ U.S.A. 《地理学报(英文版)》1991,(3)
Correspondence analysis(CA)was applied to lakewater data in order to study the effects of acidicdeposition on the geochemical composition of lakes in the Adirondacks.The lake chemistry dataanalyzed were taken from the Eastern Lake Survey-Phase I(ELS-I)conducted by the U.S.Environmental Protection Agency.CA was used to identify‘outlying’lake samples as well as‘superfluous’and‘unresolved’analytes.Correlational relationship among analytes were also examined. 相似文献
8.
《The Professional geographer》2013,65(3):321-326
A regret frequently expressed at International Geographical Congresses concerns the lack of summary information about the nature of geographic research in the host country. During a discussion of this point with members of the Association of Japanese Geographers, the idea of publishing a series of reports on various aspects of Japanese research surfaced. The concept was later enthusiastically supported by the United States National Committee for the International Geographical Union. This first report, “Historical Geography in Japan,” has been modified for the benefit of the English-speaking readers of THE PROFESSIONAL GEOGRAPHER. Although the reports will be of particular interest to those planning to attend the 1980 IGC in Tokyo, they should prove of general interest as well.—H. Jesse Walker, Member, U.S. National Committee, IGU. 相似文献
9.
RECENT DEVELOPMENTS IN MULTIVARIATE CALIBRATION 总被引：1，自引：0，他引：1
B.R.KOWALSKI M.B.SEASHOLTZ Laboratory for Chemometrics BG- University of Washington Seattle WA U.S.A. 《地理学报(英文版)》1991,(3)
With the goal of understanding global chemical processes,environmental chemists have some of the mostcomplex sample analysis problems.Multivariate calibration is a tool that can be applied successfully inmany situations where traditional univariate analyses cannot.The purpose of this paper is to reviewmultivariate calibration,with an emphasis being placed on the developments in recent years.The inverseand classical models are discussed briefly,with the main emphasis on the biased calibration methods.Principal component regression(PCR)and partial least squares(PLS)are discussed,along with methodsfor quantitative and qualitative validation of the calibration models.Non-linear PCR,non-linear PLSand locally weighted regression are presented as calibration methods for non-linear data.Finally,calibration techniques using a matrix of data per sample(second-order calibration)are discussed briefly. 相似文献
10.
TheLoessPlateauarealocatedinti1eMiddleReachesoftheYellowffiver(MRYR)isti1ecradleoftheCltinesenationandthesourceoftheancientcivilization.However,dun11galongpenodoftime,unreasonablelanduse,rapidpopulationgrowthandsenousmptiol1damagemadetheoriginalcriticaIenvirorunentevenworsened,deePlyichuencingtheeconowhcdeveloPmrmandtheimProvementoflocalpeople'slivingstandard.Thege0graplticalenvirorul1entisaco11unonandnecessaryextemalcondition.Wthsocialprogressandsciatificandtechnicaldevelopn1Cnt,theconn… 相似文献
11.
CheSalmahM.R WahizatulAfzanA. 《湿地科学》2004,2(3):184-191
Odonata larvae and adults were collected from fourteen sites of various habitats including rivers, rice fields, mountain streams, freshwater and peat swamps, oil palm, sugarcane and rubber plantations and lake. Out of 51 species recorded, Libellulidae made up the most dominant of 10 families followed by Gomphidae and Coenagrionidae. Other families were less common. Riverine and stream ecosystems were the most diverse, both with six families and 19 and 13 species respectively. In the rice fields, Libellulidae and Coenagrionidae were represented by 17 and seven species respectively. The poorest fauna of Odonata was recorded from a lake system. A few of libellulids were found to be pollution tolerant and widespread in distribution. Many odonate species were restricted to preferred habitats or water parameter gradients that could be used as bioindicators of respective habitats or parameters. 相似文献
12.
Compositional data arise naturally in several branches of science,including chemistry,geology,biology,medicine,ecology and manufacturing design.In chemistry,these constrained data seem to occur typicallywhen raw data are normalized or when output is obtained from a constrained estimation procedure,suchas might be used in a source apportionment problem.It is important not only for chemists to be awarethat the usual multivariate statistical techniques are not applicable to constrained data,but also to haveaccess to appropriate techniques as they become available.The currently available methodology is dueprincipally to Aitchison and is based on log-normal models.This paper suggests new parametric andnon-parametric approaches to significantly improve the existing methodology.In the parametric setting,some recent work of Rayens and Srinivasan is extended and a practical regression model is proposed.In the development of the non-parametric approach,minimum distance methods coupled withmultivariate bootstrap techniques are used to obtain point and region estimators. 相似文献
13.
《The Professional geographer》2013,65(3):278-282
The effects of intra-farm distance on farm income have not been previously tested in North America. European studies are inconclusive as they use data taken from bookkeeping accounts for the farm as a whole. This paper calls for field-to-field farm analyses that combine internal movement costs with costs of production, yields, and farm-gate prices. In a study applying this method to Manitoba grain farms, it was found that adjustments in the organization and intensity of farming offset the effects of distance on net income. 相似文献
14.
Orthogonal rotations,e.g,the varimax rotation,are common practice in factor analysis.However,theterm varimax rotation does not refer to a unique procedure,since several different types of rotation arepossible.In this paper six different types of rotation are examined(raw varimax of loadings,normalvarimax of loadings,raw and normal varimax of scores,eigenvalue-weighted varimax of loadings andArthur varimax)from both a theoretical and practical point of view.It can be concluded that an adequateapplication of these methods can often simplify the interpretation of the calculated factors. 相似文献
15.
《地理学报(英文版)》1978,(1)
ABSTRACT According to repeated measurements at the fixed station, geomorphological in-vestigation, documentary records and recalls of the local residents, the Batura Glacier's terminus has undergone many changes during the- Quaternary and recent time. 相似文献
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17.
Hjh Dulima Jali 《湿地科学》2003,1(1):40-50
Given that organic soil is a complex substrate and there are many environmental factors which directly or indirectly control its decomposition processes, the use of standard substrate simplify the system in that the effect of substrate quality could be eliminated and influence of certain environmental conditions such as edaphic factors, acidity and moisture could be focused on. In addition to the forest floor, decomposition potential down the peat profile can also be examined. Cotton strip assay was used to estimate decomposition potentials in tropical peat swamp occupied by different Shorea Albida peat swamp forest communities, The 'Alan Batu' , the ' Alan Bunga' , the 'Alan Padang' and the ' mixed Alan' forest communities.Greatest decay rates on the peat surface took place during the wet period. The moist condition of the wet months appeared to favour the growth and stimulate activities of decomposer population and soil invertebrates. Generally, 50% of cotton tensile loss is achieved after four weeks 相似文献
18.
《地理学报(英文版)》1995,(3)
Modemurbanmpaphy0fChinabopnitsrapiddevelOPmentinthenudl970sandreachedahightideinthel980sduetothefonnationofanewresearchclimatehighlyfavorabletOthestudoftheChinesecitiessincetherefOrmofeconowhcsystemandOPedngtothe0utsideworid.Therapiddevelopmentcouldbeiden… 相似文献
19.
Gu Chaolin 《地理学报(英文版)》1995,(1)
IntroduchonSincelg49,Chinahaschosel1thesociaIistsyste111il1tl1eIlgl1tofMaI\isl11.Itl1asplacedemphasisonti1epnn1aryindustry(eq.agriCulture)andh1esec0ndaryindtlstry(eg.themanufaCtunngindustry)andoverlookedthedeveloplnentofthetertiaryindustry(eqtherealestate… 相似文献
20.
PHILIP J.BROWN 《地理学报(英文版)》1992,(3)
Modern scanning(near-)infrared reflectance/absorption(NIR)spectroscopes measure the absorptions orreflectances at a sequence of around 1000 wavelengths.Training data may consist of 10-100 carefullydesigned sample mixtures for which the true composition of the mixture is either known by formulationor accurately determined by wet chemistry.In future one wishes to predict the true composition fromthe spectrum.In this paper we compare a simple wavelength selection approach with methods whichretain all the wavelengths.It offers a powerful yet simple technique for choosing those wavelengths thatare specific to each pure component as against the other components(including the medium)for thevarying compositions.In the presence of a defined range of ingredients it thus chooses wavelengths whichare highly selective for each particular component.It has the added advantage of selecting wavelengthswhich are little effected by interaction effects and consequent non-linearities.The calibration data used consist of 125 observations of three sugars,each varying at five levels in afull 5~3 design.The validation set consists of 21 further samples specially selected to have compositionsoutside the range of the training sample.The selection methods perform much better on this predictionset than methods which retain all the wavelengths,700 in this case.The leave-one-out cross-validationinternal to the calibration data would point to the opposite finding and suggests that such cross-validations may be overly flattering to techniques such as partial least squares and may encourageoverfitting.After selection,simple straightforward least squares methods may be used,eschewing theneed for‘shrinkage’methods such as partial least squares or ridge regression. 相似文献