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921.
The effect of peak shifts on the performance of a Kalman filter multicomponent analysis algorithm hasbeen investigated.A series of Gaussian test systems were employed to characterize the concentrationestimation errors and the morphology of the on-line residuals(the innovations sequence).Both forwardand reverse filters were used in the generation of the innovations sequences.It was found that thedifference between the forward and reverse innovations sequences gave an accurate indication of thedirection and magnitude of the peak shift.A series of overlapped two-component systems were alsoinvestigated.Again,a correlation between the difference innovations and the degree of the responseshift was observed.The behavior of the Katman filter in fitting the shifted fluorescence emissionspectrum of benzo[a]pyrene was also examined.The response for henzo[a]pyrene in cyclohexanesolution was compared to that obtained on the surface of a reversed phase thin layer chromatographyplate.A red shift of 4 nm was detected for the surface spectrum by observing the difference innovationssequence.This approach holds promise for correction of response shifts in multicomponent systems. 相似文献
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Cidália C. Fonte Nuno Martinho 《International journal of geographical information science》2017,31(12):2382-2400
The validation of land use/land cover (LULC) maps is usually performed using a reference database consisting of a sample of points or regions to which the ‘real’ class is assigned. This assignment is usually performed by specialists using photointerpretation (PI) of high-resolution imagery and/or field visits, which are time consuming and expensive processes. The aim of this article is to assess if the data available in the collaborative project OpenStreetMap (OSM) may be used as a source of data to assist the creation of these reference databases, reducing the time spent and costs associated with their generation. For this aim, two case studies were used, where the validation of the Global Monitoring for Environment and Security Urban Atlas (UA) was performed. The used methodology requires the harmonization of the data available in OSM with the UA nomenclature, and the subsequent creation of a LULC map from the OSM data. This map was then compared to UA to assess the similarity of the regions mapped in both. To test the usefulness of OSM data to assess the accuracy of UA, a sample of points was created and two reference databases generated, one assigning the data extracted automatically from OSM to the points where these data were available, and PI for the remaining points, and the other using only PI. The accuracy assessment of UA for the two case studies was then made building confusion matrixes and computing accuracy indicators. The results showed that for the two study areas, only low percentages of points had to be photo interpreted in the first reference database (respectively, 12% and 2% for the two study areas), decreasing the work load considerably. The results obtained with both reference databases are comparable for level 1 classes. For level 2 classes, worse results were obtained for some classes, showing that the OSM data used are not enough to create reliable reference data. 相似文献
926.
不动产征收前后价值变化研究对于不动产征收主体博弈分析具有重要的意义,也为不动产征收补偿价格评估提供了理论支持。主要通过城乡不动产征收前后价值变化以及被征收人利益损害的分析,探讨了不同目的下的中国不动产征收主体博弈模型及行为选择。研究认为:(1)基于预期收益原则的不动产征收价格评估为不动产征收补偿与征收增值收益分配提供了理论依据;(2)基于公共目的性征收分析表明被征收人的权益保护很大程度上依赖于政府的角色定位,基于非公共目的性征收分析表明由于增值利益分配的零和博弈冲突以及政府的惯性强势思维,对现有政策体制不可避免地带来一系列冲突;(3)基于公共目的性划分的不动产征收与国家收购两种类型有利于区别制定不动产征收政策,从而促进土地资源的合理流动与优化配置。 相似文献
927.
This study presents an integrated provenance record for ancient forearc strata in southern Alaska. Paleocene–Eocene sedimentary and volcanic strata >2000 m thick in the southern Talkeetna Mountains record nonmarine sediment accumulation in a remnant forearc basin. In these strata, igneous detritus dominates conglomerate and sandstone detrital modes, including plutonic and volcanic clasts, plagioclase feldspar, and monocrystalline quartz. Volcanic detritus is more abundant and increases upsection in eastern sandstone and conglomerate. U‐Pb ages of >1600 detrital zircons from 19 sandstone samples document three main populations: 60–48 Ma (late Paleocene–Eocene; 14% of all grains), 85–60 Ma (late Cretaceous–early Paleocene; 64%) and 200–100 Ma (Jurassic–Early Cretaceous; 11%). Eastern sections exhibit the broadest distribution of detrital ages, including a principal population of late Paleocene–Eocene ages. In contrast, central and western sections yield mainly late Cretaceous–early Paleocene detrital ages. Collectively, our results permit reconstruction of individual fluvial drainages oriented transverse to a dissected arc. Specifically, new data suggest: (1) Detritus was eroded from volcanic‐plutonic sources exposed along the arcward margin of the sampled forearc basin fill, primarily Jurassic–Paleocene magmatic‐arc plutons and spatially limited late Paleocene–Eocene volcanic centers; (2) Eastern deposystems received higher proportions of juvenile volcanic detritus through time from late Paleocene–Eocene volcanic centers, consistent with emplacement of a slab window beneath the northeastern part of the basin during spreading‐ridge subduction; (3) Western deposystems transported volcanic‐plutonic detritus from Jurassic–Paleocene remnant arc plutons and local eruptive centers that flanked the northwestern part of the basin; (4) Diagnostic evidence of sediment derivation from accretionary‐prism strata exposed trenchward of the basin fill is lacking. Our results provide geologic evidence for latest Cretaceous–early Paleocene exhumation of arc plutons and marine forearc strata followed by nonmarine sediment accumulation and slab‐window magmatism. This inferred history supports models that invoke spreading‐ridge subduction beneath southern Alaska during Paleogene time, providing a framework for understanding a mature continental‐arc/forearc‐basin system modified by ridge subduction. Conventional provenance models predict reduced input of volcanic detritus to forearc basins during progressive exhumation of the volcanic edifice and increasing exposure of subvolcanic plutons. In contrast, our results show that forearc basins influenced by ridge subduction may record localized increases in juvenile volcanic detritus during late‐stage evolution in response to accumulation of volcanic sequences formed from slab‐window eruptive centers. 相似文献
928.
Bridging organizations facilitate a range of governance processes, including cooperation and social learning, and are theorized to be a key component of robust governance systems. In this article, we use node removal simulations to test structural hypotheses of robustness in a regional water governance network in Central America. We investigate the response of network measures supporting core governance processes to the targeted removal of bridging organizations and other actors, which we compare to random and centrality-based simulations. The results indicate removing bridging organizations has a greater impact on the network than any other type of actor, suggesting bridging organizations are critical to the robustness of the governance system. Furthermore, network structures supporting cooperation may be less robust than structures facilitating social learning. We conclude with policy implications of the research findings as they relate to the exit problem in governance systems with a large presence of international development actors. 相似文献
929.
The practice of gathering and harvesting wild foods has seen renewed interest in recent decades. In addition to contributing to food security and food sovereignty, foraging plays a role in promoting socioecological resilience and creating communities of belonging. However, foraging is generally prohibited by regulations governing public lands in the United States and elsewhere. The growth in food forests suggests public policymakers and land managers’ may be interested in reconsidering this broad prohibition of foraging but require an information base to do so. While a body of research on foraging exists, news media coverage of foraging represents an additional, readily available source of input. As a consequence, framings of foraging in media coverage likely influence managers’ deliberations on this practice. The current paper uses automated content analysis to understand how the practice of gathering and consuming wild foods is framed in print and digital news media, and how these depictions have varied in a 15-year period that includes the Great Recession. Our results show that prevalent framings of foraging represent it variously as a self-provisioning practice or a source of luxury commodities and experiences, with economic uncertainty appearing to affect the frequency of each framing by news media sources. Given managers’ ease of access to them, these distinct framings may influence future regulatory landscapes of foraging. 相似文献
930.
А. T. Barabanov 《Geography and Natural Resources》2016,37(2):106-113
An analysis is made of the chief causes for degradation of agricultural lands: exhaustive agricultural land use, poor planning quality of land use management, deforestation, low volumes of forest planting and reforestation, and a high degree of plowing of lands. The principles of adaptive-landscape generation and land use practices are substantiated on the basis of a system approach to the exploitation of the natural-resource potential and a package of anti-degradation measures. The structure flowchart is given for the model of adaptive-landscape generation as developed on the basis of assessing the natural-climatic conditions, land resources, the degree of land degradation, and analyzing the set of indicators and criteria for a classification of landscapes. It is found that the key elements of the adaptive-landscape organization of land use on slopes are a typization of lands, the determination of the land use pattern, and the employment of technologies, methods and measures to ensure a normal functioning of agroecosystems. The following groups of lands are identified: gentle near-watershed slopes with a steepness of up to 2–3°; near-network lands, the lower boundary of which runs along the edge of the hydrographic network, and lands on the hydrographic network. The schematic of the organization of a large balka catchment is provided. 相似文献