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91.
Planning Geotechnical Investigation Using ANFIS 总被引:2,自引:2,他引:0
Bojan Žlender Primož Jelušič Djamalddine Boumezerane 《Geotechnical and Geological Engineering》2012,30(4):975-989
Engineering experience may be written in mathematical form by using adaptive network-based fuzzy inference system (ANFIS). In this article we propose a method to use engineering experience and build a model, which can be used as a systematic decision support tool for engineers dealing with new problems. Planning geotechnical investigations is based on experience, which are used to obtain optimal number of investigation points, field and laboratory tests. To achieve this objective we define minimum number of investigation points and several input parameters which could increase or decrease the number of investigation points. The expert’s evaluations were put in a table, from which we generate the basis of the system. The paper presents a concept for planning geotechnical investigation for buildings using ANFIS and practical examples show its usefulness. 相似文献
92.
This paper describes the implementation of process-based models reflecting relative groundwater nitrate vulnerability of the
shallow alluvial Lower Savinja Valley (LSV) aquifer in Slovenia. A spatially explicit identification of the potentially vulnerable
priority areas within groundwater bodies at risk from a chemical point of view is being required for cost-effective measures
and monitoring planning. The shallow LSV unconfined aquifer system consists of high-permeable Holocene and middle- to low-permeable
Pleistocene gravel and sand, with a maximum thickness of about 30 m, mainly covered by shallow eutric fluvisoils or variously
deep eutric cambisoil. The hydrogeological parameters, e.g. the depth to the groundwater, hydrological role of the topographic
slope, etc. usually used in different point count schemes are, in the case of the lowland aquifer and shallow groundwater,
spatially very uniform with low variability. Furthermore, the parametric point count methods are generally not able to illustrate
and analyze important physical processes, and validation of the results is difficult and expensive. Instead of a parametric
point count scheme, we experimentally used the Arc-WofE extension for weights-of-evidence (WofE) modelling. All measurement
locations with a concentration higher than the value of 20 mg NO3
− per litre of groundwater have been considered as training points (173), and the three process-based models generalized output
layers of groundwater recharge (GROWA), nitrate leached from the soil profile (SWAT) and groundwater flow velocity (FEFLOW),
served as evidential themes. The technique is based on the Bayesian idea of phenomena occurrences probability before (prior
probability) and after consideration of any evidential themes (posterior probability), which were measured by positive and
negative weights as an indication of the association between a phenomena and a prediction pattern. The response theme values
describe the relative probability that a 100 × 100 m spatial unit will have a groundwater nitrate concentration higher than
the training points’ limit values with regard to prior probability value. The lowest probability of groundwater nitrate occurrence
is in the parts of the LSV aquifer, which are known as anoxic condition areas with very likely denitrification processes.
The cross-validation of the dissolved oxygen and dissolved nitrate response theme confirmed the accuracy of the groundwater
nitrate prediction. The WofE model results very clearly indicate regional groundwater nitrate distribution and enable spatial
prediction of the probability for increased groundwater nitrate concentration in order to plan the groundwater nitrate reduction
measures and optimize the programme for monitoring the effects of these measures. 相似文献
93.
Mesozooplankton spatial distribution and community structure in the South Adriatic Sea during two winters (2015, 2016)
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Whereas the data on mesozooplankton in the epipelagic offshore Mediterranean Sea are extensive, less information is available about plankton in the deeper layers. The present study aims to describe the vertical and horizontal structure and distribution of mesozooplankton species and their associations down to 1,200 m in the water of the Southern Adriatic Sea. Zooplankton were sampled using a Nansen net of 200‐μm mesh size during two cruises in the winters of 2015 and 2016, extending from the coast to the open sea. In total, 203 zooplankton taxa were identified. The community was dominated by copepods, representing between 67% and 91% of the total abundance. The highest total densities were recorded in the upper layers where a high proportion (up to 36%) of appendicularians was also observed in the first sampled year. Five groups of samples were determined based on their community structure. In 2015 communities were distinct between the 0 and 50 m layer and the underlying one (50–100 m), whereas in 2016 epipelagic waters were inhabited by a more uniform mesozooplankton community. The mesopelagic and deep‐water fauna, especially copepods, showed a relatively stable composition in both sampling years Overall, our study confirms the oligotrophic character of the Southern Adriatic, with occasional density outbreaks of appendicularians under favourable conditions. 相似文献
94.
Implications for behavior of volatile elements during impacts—Zinc and copper systematics in sediments from the Ries impact structure and central European tektites
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Zuzana Rodovská Tomáš Magna Karel Žák Chizu Kato Paul S. Savage Frédéric Moynier Roman Skála Josef Ježek 《Meteoritics & planetary science》2017,52(10):2178-2192
Moldavites are tektites genetically related to the Ries impact structure, located in Central Europe, but the source materials and the processes related to the chemical fractionation of moldavites are not fully constrained. To further understand moldavite genesis, the Cu and Zn abundances and isotope compositions were measured in a suite of tektites from four different substrewn fields (South Bohemia, Moravia, Cheb Basin, Lusatia) and chemically diverse sediments from the surroundings of the Ries impact structure. Moldavites are slightly depleted in Zn (~10–20%) and distinctly depleted in Cu (>90%) relative to supposed sedimentary precursors. Moreover, the moldavites show a wide range in δ66Zn values between 1.7 and 3.7‰ (relative to JMC 3‐0749 Lyon) and δ65Cu values between 1.6 and 12.5‰ (relative to NIST SRM 976) and are thus enriched in heavy isotopes relative to their possible parent sedimentary sources (δ66Zn = ?0.07 to +0.64‰; δ65Cu = ?0.4 to +0.7‰). In particular, the Cheb Basin moldavites show some of the highest δ65Cu values (up to 12.5‰) ever observed in natural samples. The relative magnitude of isotope fractionation for Cu and Zn seen here is opposite to oxygen‐poor environments such as the Moon where Zn is significantly more isotopically fractionated than Cu. One possibility is that monovalent Cu diffuses faster than divalent Zn in the reduced melt and diffusion will not affect the extent of Zn isotope fractionation. These observations imply that the capability of forming a redox environment may aid in volatilizing some elements, accompanied by isotope fractionation, during the impact process. The greater extent of elemental depletion, coupled with isotope fractionation of more refractory Cu relative to Zn, may also hinge on the presence of carbonyl species of transition metals and electromagnetic charge, which could exist in the impact‐induced high‐velocity jet of vapor and melts. 相似文献
95.
Paper presents a reanalysis of four stratospheric particles registered in the Cosmic Dust Catalogs (CDC). Two particles have been classifed in the NASA Johnson Space Centre (JSC) in Houston as natural, terrestrial contaminants and the origin of the other two particles was found questionable, probably cosmic. Present study has confirmed these conclusions; however some new additional features in the chemical analysis have been found which can finally determine the classification of the particles with unclear origin. 相似文献
96.
Study of groundwaters using the environmental tritium and hydrochemical data in the Belgrade region 总被引:2,自引:1,他引:1
M. Hadžišehović M Župančić N. Miljević D. Paligorić M. Komatina 《Environmental Geology》1990,15(1):13-29
A study of tritium content and some physicochemical parameters has been performed in order to investigate interconnection between surface and atmospheric waters and underground waters in Belgrade area. Samples of the precipitation at Zeleno Brdo-Belgrade meteorological station, the Danube and the Sava river water, and underground water (Ranney wells and piezometers) have been analyzed. The3H content, the content of dissolved ions, total hardness, and electrical conductivity have been measured. The tritium data show existence of two water strata in the aquifer. The upper stratum (about 16 m thick) contains older water (mean monthly3H concentration of 17 TU) and has weak interaction with the river and the precipitation. Below this stratum lies the principal water bearing stratum, strongly connected with the river with the3H concentration similar to that of surface water (mean monthly3H concentration of 50 TU) and spreading out through the entire aquifer. The contribution of the Sava river water and the two water layers at the Ranney well are calculated starting with the hydrological aquifer model, which supposes that three water components are mixed in the pumped Ranney well water. According to calculation results using the3H concentration and physicochemical characteristics as parameters, more than 70 percent of the water pumped by the Ranney well (in 1983) comes from the Sava with a time delay of less that 15 days.Properties of tritium distribution in precipitation, river waters, and underground water in the Belgrade region are established from the results of measurements of3H concentrations in the period 1976–1983. 相似文献
97.
Sixty-one blue spectrograms of TX UMa were obtained in the years 1969–1970, mainly in phases close to the primary minimum of the eclipsing system. The radial velocity curve displays clear rotational effect from which much higher than synchronous rotational velocity of the blue (B8V) component has been formally derived. However, this discrepancy is probably due to the presence of the tenous accretion disk around the primary. The disk is apparently fed by the intermittent mass transfer as indicated by the occasional changes of orbital period of the system. From all available radial velocity data an improved set of spectroscopic orbital elements is derived. The behaviour of the spectral lines in and out of the primary minimum is compared. Metallic lines of the cold (F7IV) secondary component are clearly seen exclusively in phases 0.988 to 0.012.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain. 相似文献
98.
Observations of internal structure and development of four helical prominences are presented. We assume that the helically twisted fine structure threads are outlining magnetic field lines and we found that it is possible to describe the magnetic fields by the uniform twist configuration, with the twists ranging between 2 and 7. The estimated lower limits for the magnetic fields were about 20 G which give lower limits for the currents flowing along the prominences in the range between 2 × 1010 A and 2 × 1011 A and current densities at the axis of the prominences about 10-4 A m-2. The upper limit of electron drift velocity could be estimated as 1 m s-1, which is far below the critical velocities for the onset of plasma microinstabilities.The stability of the studied prominences is discussed and the criteria for the onset of eruptive instability are established for a prominence modelled as a twisted and elliptically curved magnetic flux tube which is anchored in the photosphere and affected by its mirror-current. The eruption starts when the prominence attains a critical height which must be larger than half of the footpoint separation and depends on the values of twist, radius, and footpoint distance of the magnetic flux tube. The observed examples of eruptive prominences agree very well with the predictions. Possible applications to the two-ribbon flare process are outlined.Properties of stable cylindrical prominences in equilibrium are analyzed and a criterion for the distinction between the Kuperus-Raadu and Kippenhahn-Schlüter types of prominences is proposed. According to established criteria, two of the studied prominences were of the Kuperus-Raadu type, while the other two were of the Kippenhahn-Schlüter type. 相似文献
99.
Curdin Derungs Tanja Samardžić 《International journal of geographical information science》2018,32(5):856-873
Data-driven GIScience shows a growing interest in making spatial information from large text data. In this paper, we quantify and thus evaluate the relation between text frequency and properties of the outer-text, geographic setting by comparing text frequencies of mountain names to the respective geomorphometric characteristics. We focus on some 2000 unique mountain names that appear some 50,000 times in a large compilation of texts on Swiss alpine history. The results on the full data set suggest only a weak relation: only 5–10% of the variation in the text frequency being explained by the respective geomorphometric characteristics. However, an analysis of multiple scales allows us to identify a Simpson’s Paradox. What appears to be ‘noise’ in the analysis of all mountains in the whole of Switzerland shows significant local signals. Small spatial extents, found all over Switzerland, can show considerably strong correlations between text frequency and spatial prominence, with up to 90% of the total variation explained. We argue that our findings have practical implications for data-driven GIScience. Retrieving meaningful spatial information from text might only be possible if the spatial scale of analysis reflects the spatial scale described in the input text documents. 相似文献
100.
In the southwestern Carpathians of SW Romania and E Serbia calc-alkaline Upper Cretaceous-Paleogene subduction related magmatic rocks occur in two main zones. The Ridanj-Krepoljin belt (E Serbia) represents the southern part of the western zone. In this belt Early Maastrichtian dacites and subordinate andesites occur, but there are indications of an unexposed granodioritic (?) magmatism about 60 Ma old. Pb-Zn-Ag and only subordinate Cu mineralization is associated with this igneous activity. The Timok magmatic complex (E Serbia) composed of Upper Cretaceous (-Paleocene?) andesites and analogue intrusives represents the eastern zone south of the Danube. Associated with this magmatism are Cu (+Au) and very subordinate Zn (±Pb) mineralization. To the north (SW Romania) in both zones mainly intrusive bodies (diorites, quartz diorites, granodiorites, monzonites) of Campanian-Paleocene age are exposed. Porphyry copper (+Mo) and in north Pb-Zn (±Cu) mineralization are related to those intrusives. The petrological and geochemical features of all these calc-alkaline rocks are very similar. It appears, however, that the associated polymetallic and the copper mineralization are both spatially and vertically separated. 相似文献