Challenges to calibration: Facing an increasingly critical environment     

Olsthoorn TN  Kamps PT 《Ground water》2006,44(6):876-879

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The Harvard-Smithsonian reference atmosphere     

O. Gingerich  R. W. Noyes  W. Kalkofen  Y. Cuny 《Solar physics》1971,18(3):347-365

We present a model of the solar atmosphere in the optical depth range from ₅₀₀₀ = 10^–8 to 25. It combines an improved model of the photosphere that incorporates recent EUV observations with a new model of the quiet lower chromosphere. The latter is based on OSO 4 observations of the Lyman continuum, on infrared observations, and on eclipse electron densities.Our model differs from the Bilderberg Continuum Atmosphere (BCA) in the low chromosphere (₅₀₀₀ < 10^–4), where deviations from local thermodynamic equilibrium in hydrogen and carbon have been taken into account. It also differs in the transition region between the chromosphere and the photosphere (10^–4 < ₅₀₀₀ < 10^–2), where the temperature is lower than in the BCA, and in the convective region (₅₀₀₀ 2), where the temperature is higher than in the BCA.  相似文献   

Understanding activity scheduling and rescheduling behaviour: Theory and numerical illustration     

Chang-Hyeon Joh  Theo A. Arentze  Harry J.P. Timmermans 《GeoJournal》2001,53(4):359-371

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Integration zeitabhängiger Funktionen mittels Glimmröhren-Kippschwinger     

Theo Dahlem  D. Paffrath 《Pure and Applied Geophysics》1968,71(1):51-55

Zusammenfassung Es wird ein im wesentlichen aus einem einfachen Kippschwinger bestehender Integrator beschrieben, der es gestattet, zeitlich veränderliche Spannungen digital zu summieren. Er ist somit zur Integration von zeitlich variablen Meßgrößen, insbesondere aus Meteorologie und Geophysik, sie sich in eine der Meßgröße proportionale Spannung umsetzen lassen, geeignet. Es werden Meß- und Anwendungsbeispiele gegeben.

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Summary An integration device consisting essentially of a simple saw-tooth oscillator is described. The instrument allows to integrate arbitrary voltages variable with time. Thus it is possible to integrate measuring functions variable with time, especially in meteorology and geophysics, that are convertible into a proportional voltage. Examples of measurements and application are represented.

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An intelligent spatial land use planning support system using socially rational agents     

Seyed Morsal Ghavami  Mohammad Taleai  Theo Arentze 《International journal of geographical information science》2017,31(5):1022-1041

This research presents an intelligent planning support system based on multi-agent systems for spatial urban land use planning. The proposed system consists of two main phases: a pre-negotiation phase and an automated negotiation phase. The pre-negotiation phase involves interaction between human actors and intelligent software agents in order to elicit the actors’ social preferences. The agents employ social value orientation theory, which is rooted in social psychology, in order to model actors’ social preferences. The automated negotiation phase involves negotiation among autonomous software agents, the aim being to achieve consensus about the spatial problem on behalf of the relevant actors and using the information obtained.

This study employs a computationally effective Bayesian learning technique, along with social value orientation theory, to design socially rational intelligent agents who work on behalf of real actors. The proposed system is applied to a real world urban land use planning case study. Human actors participate in a pre-negotiation phase, and their social preferences are elicited by intelligent software agents through a number of interactions. Then, software agents come together to engage in an automated negotiation phase and eventually reach an agreement on the spatial configuration of urban land uses on behalf of the actors. The results of the study show that the proposed system is effective at performing an automated negotiation, plus that the final plan – which is the output of the automated negotiation – produces higher social utility and better spatial land use configurations for the agents.  相似文献   

Peripherality in the global container shipping network: the case of the Southern African container port system   总被引：1，自引：0，他引：1  

Darren Ronald Fraser  Theo Notteboom  César Ducruet 《GeoJournal》2016,81(1):139-151

Regional trade co-operation, economic growth and greater political stability have enabled increased container throughput and container port capacity development. Earlier academic work has indicated that the functional position of this port region in the global maritime network might be shifting from a remote region in the periphery of the network to a more intermediate position. This paper aims to analyze the changing level of peripherality and remoteness of the Southern African container port system as part of the global container shipping network. The central hypothesis is that Southern Africa has moved from a remote shipping region to a more central shipping region in the global network. The methodology consists of the calculation of network measures for Southern African ports. The changing geographical distribution of flows among the main container ports in South Africa, Namibia, Mozambique, Mauritius and Madagascar will also be explored in terms of their respective shipping services, port calling patterns, market structure (in terms of the number of active carriers) and the up-scaling of vessel and port capacity. The overall result is a mapped port hierarchical structure with a clear indication of the shifted maritime centrality of Southern African ports from 1996 to the present decade.  相似文献   

Spatial and Temporal Variations of Trace Element Contents in Xanthoria Parietina Thalli Collected in a Highly Industrialized Area in Northern France as an Element for a Future Epidemiological Study     

D. Cuny  L. Davranche  P. Thomas  M. Kempa  C. Van Haluwyn 《Journal of Atmospheric Chemistry》2004,49(1-3):391-401

This work was made in Dunkirk, which is located on the French coast, in the north, near Belgium and Great Britain. The study concerned the industrial and urban surroundings of Dunkirk and Dunkirk itself. Objectives of our study is (1) to monitor spatial patterns and temporal trends (1995–2003) of trace element (As, Cd, Hg, Ni, Pb, V, Zn) deposition and (2) to make a first evaluation of exposed population to highest metals concentrations. This work is the first step of future epidemiological investigation. In 1995, the high lead concentrations were due to industrial emissions and to traffic. Zinc and arsenic concentrations were also high and widespread in the entire studied zone, but higher near industrial area. Mercury concentrations were limited in the western part and clearly revealed the impact of waste incinerator. We did not find any significant difference between trace element contents in lichens between 1995 and 2003 except for mercury, which decreased. In 2003, the contamination by lead was more focused in the biggest metallurgical plant, which is now the predominant source for this element. The traffic impact decreased, but there was still lead remaining. For the other elements the highest concentrations were observed near the industrial zone. Highest contaminations concern 25–33% of the population, who live near industrial zone in districts where annual average incomes are the lowest. Those results confirm the needs for a further epidemiological study, which could take place in priority where population is the most exposed.  相似文献   

Contrasting responses of dimictic and polymictic lakes to environmental change: a spatial and temporal study     

Zofia Ecaterina Taranu  Dörte Köster  Roland I. Hall  Theo Charette  Francine Forrest  Les C. Cwynar  Irene Gregory-Eaves 《Aquatic Sciences - Research Across Boundaries》2010,72(1):97-115

Although comparative analyses between dimictic and polymictic lakes have noted the key role of mixing regime in governing water quality, limnologists have historically focused on dimictic lakes, leaving polymictic lakes relatively understudied. In this study, we investigated whether the effects of agricultural development on water quality differed between dimictic and polymictic lakes in a naturally nutrient-rich region of Alberta, Canada. Through a spatial limnological analysis of 36 sites, we found that the relationship between surface water total phosphorus concentration and the percent of agriculture (% Agr) in the catchments differed between dimictic and polymictic lakes, where the proportion of variance explained was much more pronounced in the dimictic (79% explained) than in the polymictic systems (7% explained). Paleolimnological analyses of subfossil chironomids in surface sediment samples (0–1 cm) from 18 of the 36 study lakes, and in sediment core profiles from the dimictic and polymictic basins of a eutrophic lake, showed that water quality differed between mixis groups. We found that the surface sediment chironomid assemblages differed significantly between polymictic and dimictic lakes. Detailed analyses of the sediment cores demonstrated that the two basin types differed in their responses to land-use change through time, as only the dimictic basin showed a parallel increase in anoxia with increasing agricultural development. We suggest that in naturally-fertile landscapes, external nutrient loading exerts a more notable effect on dimictic lakes, whereas internal nutrient loading is more important in polymictic systems.  相似文献   

Spatial mode estimation for functional random fields with application to bioturbation problem   总被引：1，自引：1，他引：0  

Sophie Dabo-Niang  Anne-Francoise Yao  Laura Pischedda  Philippe Cuny  Franck Gilbert 《Stochastic Environmental Research and Risk Assessment (SERRA)》2010,24(4):487-497

This work provides a useful tool to study the effects of bioturbation on the distribution of oxygen within sediments. We propose here heterogeneity measurements based on functional spatial mode. To obtain the mode, one usually needs to estimate the spatial probability density. The approach considered here consists in looking each observation as a curve that represents the history of the oxygen concentration at a fixed pixel.  相似文献   

Iap general circulation models: a first step towards developing a local area model for weather prediction in nigeria     

Chineke Theo Chidiezie  Li Weiping 《大气科学进展》1999,16(1):119-132

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