Using simulated annealing for resource allocation     

Jeroen C. J. H. Aerts  Gerard B. M. Heuvelink 《International journal of geographical information science》2013,27(6):571-587

Many resource allocation issues, such as land use- or irrigation planning, require input from extensive spatial databases and involve complex decisionmaking problems. Spatial decision support systems (SDSS) are designed to make these issues more transparent and to support the design and evaluation of resource allocation alternatives. Recent developments in this field focus on the design of allocation plans that utilise mathematical optimisation techniques. These techniques, often referred to as multi-criteria decision-making (MCDM) techniques, run into numerical problems when faced with the high dimensionality encountered in spatial applications. In this paper we demonstrate how simulated annealing, a heuristic algorithm, can be used to solve high-dimensional non-linear optimisation problems for multi-site land use allocation (MLUA) problems. The optimisation model both minimises development costs and maximises spatial compactness of the land use. Compactness is achieved by adding a non-linear neighbourhood objective to the objective function. The method is successfully applied to a case study in Galicia, Spain, using an SDSS for supporting the restoration of a former mining area with new land use.  相似文献   

Did tillage erosion play a role in millennial scale landscape development?     

Jantiene E.M. Baartman  Arnaud J.A.M. Temme  Jeroen M. Schoorl  Michiel H.A. Braakhekke  Tom Veldkamp 《地球表面变化过程与地形》2012,37(15):1615-1626

Landscape evolution models (LEMs) quantitatively simulate processes of sedimentation and erosion on millennial timescales. An important aspect of human impact on erosion is sediment redistribution due to agriculture, referred to herein as tillage erosion. In this study we aim to analyse the potential contribution of tillage erosion to landscape development using LEM LAPSUS. The model is calibrated separately for a water erosion process (i) without tillage and (ii) with tillage. The model is applied to the ~250 km² Torrealvilla case study catchment, SE Spain. We were able to simulate alternating sequences of incision and aggradation, that are important on longer (millennial) timescales. Generally, model results show that tillage erosion adds to deposition in the lower floodplain area, but neither water erosion alone nor water with tillage erosion together could exactly reproduce the observed amounts of erosion and sedimentation for the case study area. In addition, scale effects are apparent. On hillslopes, tillage may contribute importantly to erosion and may fill local depressions. If assessed on the catchment scale, sediments from tillage erosion eventually reach the lower floodplain area where they contribute to deposition. However, water erosion was observed in the model simulations to be the most important process on the catchment scale. This is the first time that tillage erosion has been explicitly included in a landscape evolution model at a millennial timescale and large catchment scale. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Development of a sustainable livelihood security model for storm-surge hazard in the coastal areas of Bangladesh   总被引：2，自引：1，他引：1  

Mahmuda Mutahara  Anisul Haque  M. Shah Alam Khan  Jeroen F. Warner  Philippus Wester 《Stochastic Environmental Research and Risk Assessment (SERRA)》2016,30(5):1301-1315

Coastal communities in Bangladesh are at great risk due to frequent cyclones and cyclone induced storm-surges, which damages inland and marine resource systems. In the present research, seven marginal livelihood groups including Farmers, Fisherman, Fry (shrimp) collectors, Salt farmers, Dry fishers, Forest resource extractors, and Daily wage labourers are identified to be extremely affected by storm- surges in the coastal area of Bangladesh. A livelihood security model was developed to investigate the security status of the coastal livelihood system in a participatory approach. In the model, livelihood security consists of five components: (1) Food, (2) Income, (3) Life & health, (4) House & properties, and (5) Water security. Analytical hierarchy process was followed to assess the livelihood security indicators based on respondents’ security options. The model was verified through direct field observation and expert judgment. The Livelihood Security Model yields a Livelihood Security Index which can be used for assessing and comparing the household security level (in %) of different livelihood groups in the storm-surge prone coastal areas. The model was applied with data from two major coastal areas (Cox’s Bazar and Satkhira) of Bangladesh and is applicable to other coastal areas having similar settings.  相似文献   

Jets from black hole X-ray binaries: testing, refining and extending empirical models for the coupling to X-rays     

R. P. Fender  J. Homan  T. M. Belloni 《Monthly notices of the Royal Astronomical Society》2009,396(3):1370-1382

In this paper we study the relation of radio emission to X-ray spectral and variability properties for a large sample of black hole X-ray binary systems. This is done to test, refine and extend – notably into the timing properties – the previously published 'unified model' for the coupling of accretion and ejection in such sources. In 14 outbursts from 11 different sources we find that in every case the peak radio flux, on occasion directly resolved into discrete relativistic ejections, is associated with the bright hard to soft state transition near the peak of the outburst. We also note the association of the radio flaring with periods of X-ray flaring during this transition in most, but not all, of the systems. In the soft state, radio emission is in nearly all cases either undetectable or optically thin, consistent with the suppression of the core jet in these states and 'relic' radio emission from interactions of previously ejected material and the ambient medium. However, these data cannot rule out an intermittent, optically thin, jet in the soft state. In attempting to associate X-ray timing properties with the ejection events we find a close, but not exact, correspondence between phases of very low integrated X-ray variability and such ejections. In fact the data suggest that there is not a perfect one-to-one correspondence between the radio, X-ray spectral or X-ray timing properties, suggesting that they may be linked simply as symptoms of the underlying state change and not causally to one another. We further study the sparse data on the reactivation of the jet during the transition back to the hard state in decay phase of outbursts, and find marginal evidence for this in one case only. In summary we find no strong evidence against the originally proposed model, confirming and extending some aspects of it with a much larger sample, but note that several aspects remain poorly tested.  相似文献   

Free oscillations of a spherical anelastic earth     

Jeroen Tromp  F. A. Dahlen 《Geophysical Journal International》1990,103(3):707-723

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Local empowerment through economic restructuring in Brazil: the case of the greater ABC region     

Andrs Rodríguez-Pose  John Tomaney  Jeroen Klink 《Geoforum》2001,32(4):1

Regional and local capacity building in Brazil, as in other Latin American countries, has traditionally been linked with democracy. Whereas periods of dictatorship usually saw the establishment of a tight grip by the centre over state and local governments, democracy has been linked to greater autonomy at the regional and local levels. The revival of regional and local governments in Brazil over the last decade and a half seems to fall into this latter category. In this paper we will argue that the advent of democracy is however not the only factor behind the recent dynamism at the sub-national level, but that economic restructuring is becoming a major force behind the adoption of more pro-active attitudes and policies by local and regional governments. We will illustrate this theory with the example of the greater ABC region, in the São Paulo metropolitan area, where economic crisis and restructuring has led to inter-municipal co-operation and the creation of a local economic development council.  相似文献   

Reconstructing 20thcentury lead pollution andsediment focusing in a peat land pool (Kempen, Belgium), via 210Pbdating     

Jeroen E. Sonke  William C. Burnett  Jurian A. Hoogewerff  Sieger R. van der Laan  Jaco Vangronsveld  D. Reide Corbett 《Journal of Paleolimnology》2003,29(1):95-107

Pb-210 dating of two metal-polluted organic sedimentcores obtained near a former pyrometallurgical zinc smelter in Lommel, Belgiumhave been used to reconstruct atmospheric lead deposition rates during the20^th century. Independent knowledge concerning historical pollutionevents and ¹³⁷Cs fall-out profiles has allowed a criticalevaluation of the CRS, CIC and CF-CS models for the ²¹⁰Pb ageinterpretation. Resulting ages for the three models suggest that, in this case,the CIC model gives the most accurate interpretation of historical pollutionevents and atmospheric lead fall-out. The ²¹⁰Pbwater-sediment flux was estimated at 141–1158Bq·m^–2·yr^–1 for one site and62–106 Bq·m^–2·yr^–1 at theother site, during the last century. The large difference illustrates thatsediment focusing was important on a small spatial scale (10 m).The direction of focusing correlates with the predominant wind direction.Maximum atmospheric lead deposition rates were found to be 1.63 ± 0.59g·m^–2·yr^–1 around 1968 AD,which is 2 orders of magnitude larger than the Belgian average in 1980 AD, and5 orders larger than Holocene atmospheric lead deposition.  相似文献   

Variational principles for surface wave propagation on a laterally heterogeneous Earth—I. Time-domain JWKB theory     

Jeroen Tromp  F. A. Dahlen 《Geophysical Journal International》1992,109(3):581-598

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Valueloading And Uncertainty In A Sector-based Differentiation Scheme For Emission Allowances     

Heleen Groenenberg  Jeroen Van Der Sluijs 《Climatic change》2005,71(1-2):75-115

The Triptych approach is a sectoral approach for differentiation of quantitative greenhouse gas emission reduction objectives. In this study we investigate the ranges in emission reduction targets that result from differences in valueladen assumptions and uncertainties in input data and parameters. In order to assess the effect of highly valueladen assumptions on resulting objectives we used two approaches. First we performed a sensitivity analysis. Then we elaborated the approach from four ideal-typical value-orientations: the administrator, the businessman, the campaigner and the survivor. For each of these value-orientations we specified corresponding sets of assumptions of highly valueladen parameters. Within each set, we also assessed uncertainties for the remaining parameters and input data. We assessed the strength and we quantified their inexactnesses with probability distribution functions. Next, we carried out Monte Carlo simulations in each of the four value-orientations to quantify error propagation from the inexactnesses in input data and parameters. We found targets for the year 2015 for Annex I countries differed up to around 20%-points over the four value-orientations. For developing countries differences in allowances were found up to the order of four. In addition, results are affected to a large extent by uncertainties in the other input data and parameters. Ranges in the outcome resulting from uncertainties are between 10 and 35%-points for Annex I countries, depending on the value-orientation chosen and between 20 and 120%-points for non-Annex I countries. However, the ranking of countries within the calculated differentiation remains roughly the same, an exception being the ranking that resulted from the businessman’s perspective. Other consistent combinations of valueladen assumptions may result in objectives that are outside the range that we based on the four value-orientations. We concluded that care should be taken when assessing valueloading in calculations schemes for emissions objectives based on a limited number of value-orientations only. Our analysis clearly underlines the relevance of making explicit policy variables in schemes for the differentiation of commitments. It is necessary to reach consensus on these variables if such schemes are to support negotiations on greenhouse gas emissions allowances.  相似文献   

Seismic tomography, adjoint methods, time reversal and banana-doughnut kernels   总被引：5，自引：0，他引：5  

Jeroen Tromp  Carl Tape  Qinya Liu 《Geophysical Journal International》2005,160(1):195-216

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