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Comparisons of measured and model-predicted atmospheric copper concentrations show a severe underestimation of the observed concentrations by the models. This underestimation may be (partly) due to underestimated emissions of copper to air. Since the phase out of asbestos brake lining material, the composition of brake lining material has changed and may contain up to ∼15% copper. This makes brake wear from vehicles potentially an important source of atmospheric (particulate) copper concentrations. In this paper, we reassess the copper emissions due to exhaust emissions and brake wear from road transport. Overall, our reassessments result in an estimate of total copper emission to air in UNECE-Europe of 4.0-5.5 ktonnes yr-1, which is substantially higher than the previous estimate of 2.8 ktonnes yr-1. Copper concentrations over Europe are calculated with the LOTOS-EUROS model using the revised emission data as model input. The results show that the revised emission estimates are a major step towards gap closure of predicted versus observed copper concentrations in ambient air. Brake wear emissions may be responsible for 50-75% of the total copper emissions to air for most of Western Europe. The hypothesis that road transport is an important source of copper emissions is tested and confirmed by (1) reviewing available literature data of chemically speciated PM data from road tunnel studies and (2) the gradient observed in copper concentrations from ambient PM monitoring going from rural sites to street stations. The literature review and observational data suggest that the majority of the emitted PM10 brake wear particles is in the PM2.5-10 size range. The results of this study indicate that modification of brake lining composition is an important mitigation option to reduce copper exposure of the population in Western Europe. © 2007 Elsevier Ltd. All rights reserved.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:22:23Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:45:54Z : No. of bitstreams: 1 2-s2.0-36549018192.pdf: 990563 bytes, checksum: 2db10f19c763a71ca98bf6218ee934d3 (MD5) Made available in DSpace on 2014-05-27T11:22:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-01-01 In this paper is presented a region-based methodology for Digital Elevation Model segmentation obtained from laser scanning data. The methodology is based on two sequential techniques, i.e., a recursive splitting technique using the quad tree structure followed by a region merging technique using the Markov Random Field model. The recursive splitting technique starts splitting the Digital Elevation Model into homogeneous regions. However, due to slight height differences in the Digital Elevation Model, region fragmentation can be relatively high. In order to minimize the fragmentation, a region merging technique based on the Markov Random Field model is applied to the previously segmented data. The resulting regions are firstly structured by using the so-called Region Adjacency Graph. Each node of the Region Adjacency Graph represents a region of the Digital Elevation Model segmented and two nodes have connectivity between them if corresponding regions share a common boundary. Next it is assumed that the random variable related to each node, follows the Markov Random Field model. This hypothesis allows the derivation of the posteriori probability distribution function whose solution is obtained by the Maximum a Posteriori estimation. Regions presenting high probability of similarity are merged. Experiments carried out with laser scanning data showed that the methodology allows to separate the objects in the Digital Elevation Model with a low amount of fragmentation. Universidade Estadual Paulista Faculdade de Ciências e Tecnologia Programa de Pós-Graduação em Ciências Cartográficas, Rua Roberto Simonsen, 305, Presidente Prudente, SP Universidade Estadual Paulista Faculdade de Ciências e Tecnologia Departamento de Cartografia, Rua Roberto Simonsen, 305, Presidente Prudente, SP Universidade Estadual Paulista Faculdade de Ciências e Tecnologia Departamento de Matemática, Estatística e Computação, Rua Roberto Simonsen, 305, Presidente Prudente, SP Universidade Estadual Paulista Faculdade de Ciências e Tecnologia Programa de Pós-Graduação em Ciências Cartográficas, Rua Roberto Simonsen, 305, Presidente Prudente, SP Universidade Estadual Paulista Faculdade de Ciências e Tecnologia Departamento de Cartografia, Rua Roberto Simonsen, 305, Presidente Prudente, SP Universidade Estadual Paulista Faculdade de Ciências e Tecnologia Departamento de Matemática, Estatística e Computação, Rua Roberto Simonsen, 305, Presidente Prudente, SP

The main objective of the present study is to investigate Turkey's fossil fuels demand, projection and supplies by giving the structure of the Turkish industry and Turkish economic conditions. This present study develops several scenarios to analyze fossil fuels; such as, coal, oil and natural gas consumption and make future projections based on Genetic Algorithm (GA) notion, and examines the effect of the design parameters on the fossil fuels utilization values. The models developed in the nonlinear form are applied to the coal, oil and natural gas demand of Turkey. Several Genetic Algorithm Demand Estimation Models (GA-DEM) are developed to estimate the future coal, oil and natural gas demand values based on population, Gross National Product (GNP), import, export figures. It may be concluded that the proposed models can be used as an alternative solution and estimation techniques for the future fossil fuel utilization values of any country. Oil is the most important fuel in Turkey, contributing 43% of the Total Primary Energy Supply (TPES), followed by coal (almost 30% of TPES) and natural gas (11.8%). In the study, coil, oil and natural gas consumption of Turkey are projected. Estimation shows that the coal, oil and natural gas consumption values may increase 2.82, 1.73 and 4.83 times from 2000 to 2020. Copyright © 2007 by ASME.

Radiocarbon levels in annual plants provide a means to map out regional and continental-scale fossil fuel plumes in surface air. We collected corn (Zea mays) across North America during the summer of 2004. Plants from mountain regions of western North America showed the smallest influence of fossil fuel-derived CO2 with a mean Δ14C of 66.3‰ ±1.7‰. Plants from eastern North America and from the Ohio-Maryland region showed a larger fossil fuel influence with a mean Δ14C of 58.8‰ ± 3.9‰ and 55.2‰ ± 2.3‰, respectively, corresponding to 2.7 ppm ± 1.5 ppm and 4.3 ppm ± 1.0 ppm of added fossil fuel CO2 relative to the mountain west. A model–data comparison suggests that surveys of annual plant Δ14C can provide a useful test of atmospheric mixing in transport models that are used to estimate the spatial distribution of carbon sources and sinks.

In this article we show that brake wear from road traffic vehicles is an important source of atmospheric (participate) copper concentrations in Europe. Consequently, brake wear also contributes significantly to deposition fluxes of copper to surface waters. We estimated the copper emission due to brake wear to be 2.4 kiloton per year. For comparison, the official database for Europe (without brake wear) totals 2.6 kiloton per year. In Western Europe the brake wear emissions dominate the total emission of copper. Using the spatially resolved emission data, copper distributions over Europe were calculated with the LOTOS-EUROS model. Without brake wear the model underestimates observed copper concentrations by a factor of 3, which is in accordance with other studies. Including the brake wear emissions largely removes the bias. We find that 75% of the atmospheric copper input in the North Sea may be due to brake wear. We estimate that about 25% of the total copper input in the Dutch part of the North Sea stems from brake wear. Although the estimated brake wear copper emission is associated with a large uncertainty, it significantly improves our understanding of the copper cycle in the environment. © IWA Publishing 2007.

This study explores the potential of integrating two different artificial intelligence techniques, namely neural network and fuzzy logic, effectively to model the rainfall-runoff process from rainfall and runoff information. The integration is achieved through representing fuzzy system computations in a generic artificial neural network (ANN) architecture, which is functionally equivalent to a fuzzy inference system. The model is initialized by a hyperellipsoidal fuzzy clustering (HEC) procedure, which identifies suitable numbers of fuzzy if-then rules through proper partition of the input space. The parameters of the membership functions are optimized using a nonlinear optimization procedure. The consequent functions are chosen to be linear in their parameters, and a standard least squares error method is employed for parameter estimation. The proposed model is tested on two case studies: Narmada basin in India and Kentucky basin in the United States. The results are highly encouraging as the model is able to explain more than 92% of the variance. The performance of the proposed model is found to be comparable to that of an adaptive neural based fuzzy inference system (ANFIS) developed for both the basins. The number of parameters in the proposed model is fewer compared to ANFIS, and the former can be trained in lesser time. It is also observed that the proposed model simulates the peak flow better than ANFIS. Overall, the study suggests that the proposed model can potentially be a viable alternative to ANFIS for use as an operational tool for rainfall runoff modeling purposes. Copyright 2007 by the American Geophysical Union.

Most estimates of sea spray aerosol source functions have used indirect means to infer the rate of production as a function of wind speed. Only recently has the technology become available to make high frequency measurements of aerosol spectra suitable for direct eddy correlation determination of the sea spray particle flux. This was accomplished in this study by combining a newly developed fast aerosol particle counter with an ultrasonic anemometer which allowed for eddy covariance measurements of size-segregated particle fluxes. The aerosol instrument is the Compact Lightweight Aerosol Spectrometer Probe (CLASP) - capable of measuring 8-channel size spectra for mean radii between 0.15 and 3.5 μm at 10 Hz. The first successful measurements were made during the Waves, Air Sea Fluxes, Aerosol and Bubbles (WASFAB) field campaign in October 2005 in Duck (NC, USA). The method and initial results are presented and comparisons are made with recent sea spray source functions from the literature.

A genetic algorithm rainfall intensity (GARI) model has been developed and used to predict the intensities for given return period. It is a one-step solution procedure that may not require any mathematical transformation. The problem formulation is given and the genetic algorithm solution of the problem is presented. The results show that the proposed GARI model can be used to solve the rainfall intensity-duration-frequency relations with lowest mean-squared error between measured and predicted intensities. Predicted intensities are in good agreement between measured and predicted values for given return periods. Copyright (c) 2006 John Wiley & Sons, Ltd.

The rapid and continuing changes in travel and mobility needs in India over the last decade necessitates the development and use of dynamic models for travel demand forecasting rather than cross-sectional models. In this context, this paper investigates mode choice dynamics among workers in Chennai city, India over a period of five years (1999-2004). Dynamics in mode choice is captured at four levels: exogenous variable change, state-dependence, changes in users' sensitivity to attributes, and unobserved error terms. The results show that the dynamic models provide a substantial improvement (of over 500 log-likelihood points and ?2 increases from 44% to 68%) over the cross-sectional model. The performance was compared using two illustrative policy scenarios with important methodological and practical implications. The results indicate that cross-sectional models tend to provide inflated estimates of potential improvement measures. Improving the Level of Service (LOS) alone will not produce the anticipated benefits to transit agencies, as it fails to overcome the persistent inertia captured in the state-dependence factors. The results and models have important applications in the context of growing motorization and congestion management in developing countries. � Springer Science+Business Media, LLC 2007.

One of the most critical lessons of the recent earthquakes is the need for seismic planning for lifelines, with appropriate supplies and back up systems for emergency repair and restoration. Seismic planning, however requires physical loss estimations before the earthquakes occur. Buried pipeline damage correlations are critical part of loss estimation procedures applied to lifelines for future earthquakes. We review the existing pipeline damage relationships only for ground shaking (transient ground deformations) in the light of recent developments and evaluate them with Denizli City, Turkey water supply system. Eight scenario earthquakes with four different earthquake magnitudes between M6 and M7 caused by two different fault ruptures (Pamukkale and Karakova-Akhan Faults) were used. Analyses were performed by using Geographical Information Systems (GIS). This high number of different scenario earthquakes made it possible to compare the pipeline damage relationships at different ground shaking levels. Pipeline damage estimations for Denizli City were calculated for each damage relationship and earthquake scenario. Relative effects of damage relationships and scenario earthquakes on the results were compared and discussed. The results were presented separately for brittle, ductile, and all pipelines. It was shown that the variation in ductile pipeline damage estimations by various relationships was higher than the variation in brittle pipeline damage estimations for a particular scenario earthquake. © Springer 2006.

In this article we show that brake wear from road traffic vehicles is an important source of atmospheric (participate) copper concentrations in Europe. Consequently, brake wear also contributes significantly to deposition fluxes of copper to surface waters. We estimated the copper emission due to brake wear to be 2.4 kiloton per year. For comparison, the official database for Europe (without brake wear) totals 2.6 kiloton per year. In Western Europe the brake wear emissions dominate the total emission of copper. Using the spatially resolved emission data, copper distributions over Europe were calculated with the LOTOS-EUROS model. Without brake wear the model underestimates observed copper concentrations by a factor of 3, which is in accordance with other studies. Including the brake wear emissions largely removes the bias. We find that 75% of the atmospheric copper input in the North Sea may be due to brake wear. We estimate that about 25% of the total copper input in the Dutch part of the North Sea stems from brake wear. Although the estimated brake wear copper emission is associated with a large uncertainty, it significantly improves our understanding of the copper cycle in the environment. © IWA Publishing 2007.

This paper empirically studies the effects of service offshoring on white-collar employment, using data for more than 100 US occupations over the period 1997--2006. A model of firm behaviour based on separability allows derivation of the labour demand elasticity with respect to service offshoring for each occupation. Estimation is performed with quasi-maximum likelihood, to account for high degrees of censoring in the employment variable. The estimated elasticities are then related to proxies for the skill level and the degree of tradability of the occupations. Results suggest that service offshoring is skill-biased, because it increases employment in more skilled occupations relative to less skilled occupations. At a given skill level, however, service offshoring penalizes tradable occupations relative to non-tradable occupations. Copyright , Wiley-Blackwell.

Bu çalışmada, Zonguldak’ta Rüzgâr hızı, Hava sıcaklığı, Toprak sıcaklığı, Deklinasyon açısının sinüsü, Nem miktarı, Güneş ışınımı alımının gün uzunluğuna oranı ve Aylık ortalama atmosfer dışı güneş ışınımı gibi meteorolojik ve coğrafi parametrelerinin aylık ortalama güneş ışınımı şiddeti ile aralarındaki ilişkiler araştırılmıştır. Bu etkilerin belirlenebilmesi için Zonguldak iline ait 1995 ile 2004 yılları arasındaki on yıllık aylık ortalamalar halindeki yedi veriye lineer ve çoklu lineer regresyon analizi uygulanarak modeller geliştirilmiştir. Geliştirilen modeller arasından en yüksek ve en düşük korelâsyona sahip olan modeller seçilerek Ocak/2005 ve Aralık/2005 arasındaki toplam güneş ışınımının aylık ortalamaları hesaplanmış ve 2005 yılında ölçülmüş olan veriler ile karşılaştırılmıştır. Ölçülen değerler ile hesaplanan değerler arasında ortalama % 6’lık bir sapma olduğu tespit edilmiştir. In this study, the relationships between, monthly average solar radiation and some meteorological and geographical parameters of Zonguldak such as; wind velocity, air temperature, soil temperature, sinus of declination angle, humidity, the ratio of solar irradiation to daytime length, and monthly average of extraterrestrial solar radiation were investigated. To determine these effects, some models were developed by applying multiple linear regression analysis on seven data of monthly average belonging to ten years of Zonguldak from 1995 to 2004. Among the developed models, the ones with the highest and the lowest correlation were chosen and then the monthly average of total solar radiation between January/2005 and December/2005 were estimated, and were compared with the data measured in 2005. An average deviation 6% is determined between the measured and estimated values.

Estimation of probability distribution and return periods of flood peak flows is needed for the planning, design, and management of flood control. Much of the research on at-site and regional flood frequency analysis has focused on the determination of the best probability distribution. The first objective of this study was to determine, evaluate and compare the goodness of fit of popular probability distribution functions (PDFs) to sequences of annual maximum stream-flows measured in West Mediterranean river basins of Turkey. Besides Gumbel distribution, which is generally preferred because of its simplicity and generality in extreme hydrologic data, distributions like Pareto, Log-logistic, Pearson Type III, Log-Pearson Type III, Log-normal with two and three parameters, and Generalized Extreme Value distributions are applied to the series of annual floods with time periods ranging from 20 to 61 years for 37 gauging stations. Another objective of the study was to compare and evaluate the parameter estimation methods and goodness of fit tests for the basins. For parameter estimation, the traditionally used method of moments and, recently widely used, that of probability weighted moments were used. To make an evaluation of the suitability of the parameters obtained by both methods to the data, detailed chi-square (parametric) tests were applied twice with equal-length intervals, equal-probability intervals and Kolmogorov-Smirnov (non-parametric) goodness-of-fit tests. The results demonstrated that when chi-square goodness of fit test is applied for both parameter estimation methods (moments and probability weighted moment methods), Gumbel probability distribution was obtained as the best fitting one to the floods in West Mediterranean river basins in Turkey, according to chi-square test with equal-probability and equal-length class intervals for both of the methods. Besides, the application of chi-square goodness of fit test for both parameter estimations with average chi-square approach resulted in Log-Pearson Type III for both with equal class intervals as optimal distribution. Similar results were obtained for chi-square distribution with equal probability approach. Log-Pearson Type III distribution was the best suitable one for each of the parameter estimation methods in Kolmogorov-Smirnov goodness of fit test. These results indicated that it may be more appropriate to use Log-Pearson Type III distribution instead of the widely used Gumbel distribution for probability distribution modeling of extreme values in West Mediterranean river basins. © by PSP 2007.

Comparisons of measured and model-predicted atmospheric copper concentrations show a severe underestimation of the observed concentrations by the models. This underestimation may be (partly) due to underestimated emissions of copper to air. Since the phase out of asbestos brake lining material, the composition of brake lining material has changed and may contain up to ∼15% copper. This makes brake wear from vehicles potentially an important source of atmospheric (particulate) copper concentrations. In this paper, we reassess the copper emissions due to exhaust emissions and brake wear from road transport. Overall, our reassessments result in an estimate of total copper emission to air in UNECE-Europe of 4.0-5.5 ktonnes yr-1, which is substantially higher than the previous estimate of 2.8 ktonnes yr-1. Copper concentrations over Europe are calculated with the LOTOS-EUROS model using the revised emission data as model input. The results show that the revised emission estimates are a major step towards gap closure of predicted versus observed copper concentrations in ambient air. Brake wear emissions may be responsible for 50-75% of the total copper emissions to air for most of Western Europe. The hypothesis that road transport is an important source of copper emissions is tested and confirmed by (1) reviewing available literature data of chemically speciated PM data from road tunnel studies and (2) the gradient observed in copper concentrations from ambient PM monitoring going from rural sites to street stations. The literature review and observational data suggest that the majority of the emitted PM10 brake wear particles is in the PM2.5-10 size range. The results of this study indicate that modification of brake lining composition is an important mitigation option to reduce copper exposure of the population in Western Europe. © 2007 Elsevier Ltd. All rights reserved.

In the context of environmental protection, the transfer of aerosols to vegetative canopies must be properly estimated, since aerosols constitute a preferential transport pathway for atmospheric pollution (bacteriological, chemical or radioactive). In order to properly assess the transport of pollutants, it is essential to accurately determine their dry deposition fluxes. Previous studies conducted around a nuclear site showed that the deposition prediction models do not yield an accurate representation of measured radionuclide activity (mainly 106Ru) in grasses, with observed discrepancies probably attributable to an underestimate of the dry deposition velocities. In addition, the literature mentions uncertainties in the order of two decades for the deposition velocities of particles larger than 1 urn, and little experimental data is available for submicronic particles. In order to reduce these uncertainties and choose a suitable model, a series of experiments to measure the dry deposition velocities of aerosols has been scheduled for 2005-2007. This document presents the method used and the results obtained for a fine aerosol (0.24 μm) dispersed over a prairie under neutral or unstable meteorological conditions. The technique used consists of generating a monodispersed fluorescein aerosol. The fluorescein concentration is measured in the grass and air by spectrofluorimetry and used to obtain the dry deposition velocities. A second approach using natural radioactivity (214Pb) and gamma spectrophotometry measurements has enabled the confirmation of the results obtained. The mean deposition velocities measured in this first series of experiments for a prairie-type substrate vary between 4 10-4 and 2 10-3 m.s-1. The comparison with the Slinn, Zhang and Wesely models shows that the first of these underestimates the deposition velocities by a factor of 5 to 20 and the other two more accurately represent the experimental measurements, with model/measurement discrepancies of generally less than 2.

We present a method for estimating monthly burned area globally at 1° spatial resolution using Terra MODIS data and ancillary vegetation cover information. Using regression trees constructed for 14 different global regions, MODIS active fire observations were calibrated to burned area estimates derived from 500-m MODIS imagery based on the assumption that burned area is proportional to counts of fire pixels. Unlike earlier methods, we allow the constant of proportionality to vary as a function of tree and herbaceous vegetation cover, and the mean size of monthly cumulative fire-pixel clusters. In areas undergoing active deforestation, we implemented a subsequent correction based on tree cover information and a simple measure of fire persistence. Regions showing good agreement between predicted and observed burned area included Boreal Asia, Central Asia, Europe, and Temperate North America, where the estimates produced by the regression trees were relatively accurate and precise. Poorest agreement was found for southern-hemisphere South America, where predicted values of burned area are both inaccurate and imprecise; this is most likely a consequence of multiple factors that include extremely persistent cloud cover, and lower quality of the 500-m burned area maps used for calibration. Application of our approach to the nine remaining regions yielded comparatively accurate, but less precise, estimates of monthly burned area. We applied the regional regression trees to the entire archive of Terra MODIS fire data to produce a monthly global burned area data set spanning late 2000 through mid-2005. Annual totals derived from this approach showed good agreement with independent annual estimates available for nine Canadian provinces, the United States, and Russia. With our data set we estimate the global annual burned area for the years 2001-2004 to vary between 2.97 million and 3.74 million km2, with the maximum occurring in 2001. These coarse-resolution burned area estimates may serve as a useful interim product until long-term burned area data sets from multiple sensors and retrieval approaches become available.

Different estimation methods for covariance parameters in meta-analyses can result in conflicting p-values concerning the test of treatment effect. We propose a valid method to overcome this problem at least partially by introducing a new estimator for the standard deviation of the common treatment difference.

Models have played an important role in scientific research for a long time. The crop models try to simulate the functioning of the atmosphere-soil-plant system with the help of computers. These models can be effective tools in research, education and solving agricultural and environmental protection related problems. The 4M package includes a crop model and several accessories that help to operate the model. The 4M crop model is a daily-step, deterministic model that simulates the water and nutrient balance of the soil, the soil-plant interactions and the plant development and growth. To mention some examples: (1) The package can be used in education to carry out 'zero-cost' virtual agricultural experiments and to challenge and enhance the system oriented thinking of the students. (2) In research it can be used for designing experiments and estimating the present and future characteristics of the investigated system. (3) In practical applications the package can be used to prepare agro-technological advise (fertilization, irrigation, etc.) for farmers, and to carry out economical analyses on farm level.

Hatchling sex ratios in the loggerhead turtle (Caretta caretta) were estimated by placing electronic temperature recorders in 21 nests at Fethiye beach during 2000-2002. Over the seasons, the mean temperature in the middle third of the incubation period ranged from 26.7 to 32.1°C, and incubation periods ranged from 49 to 67 days. Based on the mean temperatures during the middle third of the incubation period, and on histologically sexed dead hatchlings, the sex ratios of hatchlings at Fethiye beach were roughly equal, i.e. 60-65% of the hatchlings were females. This contrasts with the highly female-skewed sex ratios in loggerhead turtles elsewhere; Fethiye has a relatively high proportion of male hatchlings. For endangered sea turtles, the knowledge of hatchling sex ratios at different beaches, coupled with appropriate conservation measures, can make an important contribution to their survival. © Springer-Verlag 2006.

International audience; A frontier estimation method for a set of points on a plane is proposed, being optimal in L 1-norm on a given class of β-Holder boundary functions under β ∈ (0, 1]. The estimator is defined as sufficiently regular linear combination of kernel functions centered in the sample points, which covers all these points and whose associated support is of minimal surface. The linear combination weights are calculated via solution of the related linear programming problem. The L 1-norm of the estimation error is demonstrated to be convergent to zero with probability one, with the optimal rate of convergence.

Una de las principales aportaciones del análisis de datos de panel es que permite medir efectos y comportamientos que no es posible identificar en datos puros de series temporales o de corte transversal. Cuando se plantea la cuestión de cuál es la especificación más adecuada a nuestra situación de estudio con datos de panel, o cuál el método de estimación más apropiado, los contrastes de hipótesis suponen una herramienta útil que permite dar soporte o rechazar determinados supuestos. La doble dimensionalidad de los conjuntos de datos de panel permite en algunos casos adaptar los contrastes de hipótesis ya planteados para alguna de sus dos dimensiones, y en otros, ha requerido el planteamiento de tests propios de los datos de panel. En este trabajo se recogen algunos de los contrastes más frecuentes que pueden plantearse cuando se trabaja con datos de panel, y se presenta una aplicación al estudio de los efectos de la inversión pública federal mexicana, con datos de los estados mexicanos durante el periodo 1970-2000.

This paper describes the use of stochastic search processes that are the basis of genetic algorithms (GAs), in developing Turkey's electric energy estimation. The industrial sector electricity consumptions and the totals are estimated, based on the basic indicators of the gross national product, population, import and export figures. Two different non-linear estimation models are developed using GA. Developed models are validated with actual data, while future estimation of electricity demand is projected between 2002 and 2025. It may be concluded that the both GAs can possibly be applied to estimate electric energy consumption. (C) 2004 Elsevier Ltd. All rights reserved.

This article proposes new models for estimating transport demand using a genetic algorithm (GA) approach. Based on population, gross national product and number of vehicles, four forms of the genetic algorithm transport planning (GATP) model are developed - one exponential and the others taking quadratic forms - and applied to Turkey. The best fit models in terms of minimum total average relative errors in the test period are selected for future estimation. Demand management strategies are proposed based on three scenarios: restricting private car use, restricting truck use and the simultaneous management of private car use and goods movement. Results show that the GATP model may be used to estimate transport demand in terms of passenger-kilometers traveled (pass-km), vehicle-kilometers traveled (veh-km) and ton-kilometers completed (ton-km). Results also show that the third scenario - simultaneous restrictions on private car use and goods movement - could reduce total veh-km by about 35% by 2025 in this study of Turkish rural roads. C1 Pamukkale Univ, Fac Engn, Dept Civil Engn, TR-20017 Denizli, Turkey.

L'ensilage de maïs est largement utilisé pour l'alimentation des ruminants à haut potentiel ; sa valeur alimentaire est le principal facteur influençant les performances des animaux. L'étude des sources de variation et la mise en évidence des critères qui conditionnent la qualité des maïs fourragers est nécessaire pour sélectionner les variétés de demain. Pendant 34 ans, 2 383 mesures de digestibilité d'ensilages de maïs portant sur 478 hybrides ont été réalisées à l'INRA de Lusignan. Ces mesures avec moutons castrés standards ont porté sur tous les types d'hybrides : précoces, tardifs, inscrits, expérimentaux ou encore mutants bm3. La variabilité de la valeur énergétique des ensilages est très importante et elle est fortement conditionnée par la digestibilité des parois (CUDndf). Si le maïs a une valeur énergétique moyenne de 0,89 UFL, les valeurs mesurées vont de 0,74 à 1,01 UFL. Les hybrides précoces sont plus digestibles que les hybrides tardifs ; les variétés récentes sont en moyenne moins digestibles que les variétés anciennes. Enfin, la mise au point d'outils de prédiction de la digestibilité in vivo de la matière organique ou du NDF, utilisables en routine, devraient permettre aux sélectionneurs de proposer des variétés avec des valeurs alimentaires plus élevées., The feeding value of maize silage, which is equal to the product of the voluntary intake by the digestibility, is the main factor influencing the performance of livestock. It is necessary to study the sources of its variation and show the factors responsible for the quality of forage maize in order to breed to-morrow's cultivars. For 34 years, from 1958 to 2002, 2383 measurements of digestibility of maize silage were carried out on 478 hybrids at the INRA station in Lusignan. These measurements, made with standard castrated rams, concerned all types of hybrids : early heading, late heading, registrated, experimental, and also bm3 mutants. Results show a very large variation in the energy value of the silages, linked to the hybrid utilized, and under the strong influence of cell-wall digestibility (CUDndf). On average, the energy value of maize is 0.89 UFL (fodder unit fort milk), but the measured values ranged from 0.74 to 1.01 UFL. Various comparisons showed for instance that the early-heading hybrids are more digestible than the late heading ones, and that the more recent cultivars are on average less digestible than the old ones. Lastly, new tools for the prediction of the in vivo digestibility of the organic matter, or of the NDF, should give the breeders the possibility of creating cultivars with better feeding values.

Un test d'évaluation de la résistance des plantules de luzerne (M. sativa) au puceron du pois a été appliqué à différents écotypes et cultivars de Medicago annuelles. La mortalité des plantules notée le 27ème jour d'une infestation aphidienne contrôlée (infestations avec 150 mg d'aphides à deux reprises séparées d'une semaine avec arrêt de l'infestation après 13 jours) et la matière sèche des plantes survivantes à cet instant, constituent les critères de résistance. Nous avons estimé, sur la base de la variabilité des résultats que six répétitions de barquettes contenant 50 plantules permettent de différencier des accessions présentant des différences de mortalité des plantules de 20%. La variabilité génétique étudiée a porté sur les espèces M. truncatula, M. italica et M. littoralis, et a intégré la plante hôte d'origine des pucerons (la luzerne ou le pois). Sur la base de critères biochimiques (allozymes), ces deux origines aphidiennes se sont révélées très différentes. Les accessions de Medicago annuelles testées s'avèrent toutes résistantes au puceron du pois prélevé sur le pois (mortalité des plantules inférieures à 15%), mais présentent des niveaux de résistance très contrastés (de 2.7% à 98.6% de plantules mortes) lorsqu'on les confronte aux aphides provenant de la luzerne. Les paramètres biologiques des aphides (survie des insectes et taux de reproduction) sont affectés par les accessions résistantes., A standardized seedling test of lucerne (Medicago sativa L.) resistance to the pea aphid (Acyrthosiphon pisum Harris) was applied to several annual Medicago species. A unit consisted in a tray containing a soil mixture in which 50 seedlings of the same accession were transferred at the cotyledon stage. A fixed biomass of 150 mg aphids at D and at D+7 was used to infest the seedlings, and aphid multiplication was stopped at D+13. At the end of the test, at D+27, accessions were ranked according to two criteria, seedling survival and dry matter of the surviving seedlings. We calculated that 6 replicates (6 units) per accession were enough to distinguish accessions differing by 20% in seedling mortality. In a preliminary test, 46 accessions of Medicago truncatula, Medicago littoralis, Medicago italica were tested on the basis of 1 replicate per accession. Ten accessions were then chosen among the most resistant accessions to investigate the effect of aphid host plant (lucerne, pea) on plant resistance. Previous studies had shown the existence of host races in A. pisum. Taking into account allozyme polymorphism at four loci and colour polymorphism, we have shown that aphid populations on pea were composed of one predominant genotype, while aphid populations on alfalfa were composed of 3 to 4 genotypes different from the one observed on pea. Seedling tests with aphids from pea revealed that all accessions were resistant to the pea aphid (seedling mortality < 15%), while variability of accession resistance was high with aphids collected in alfalfa (seedling mortality ranged from 2,7% to 98,6%). Biological tests on the effect of the resistant accessions on aphid survival and reproduction showed that these criteria were both affected by plant resistance.

In this paper, we examine the relationships between health care visits to general practitioners, public sector specialists and private sector specialists using data from Italy, which has a mixed public-private health care system. We develop a simultaneous equations model that allows for the discreteness of measures of utilization and estimate this model using maximum simulated likelihood. Once common unobserved heterogeneity is properly accounted for, general practitioners, public specialists and private specialists are found to be substitute sources of medical care. In contrast, a naive model finds they are complements.

Este documento estima modelos lineales y no-lineales de correccion de errores para los precios spot de cuatro tipos de cafe. En concordancia con las leyes economicas, se encuentra evidencia que cuando los precios estan por encima de su nivel de equilibrio, retornan a este mas lentamente que cuando estan por debajo. Esto puede reflejar el hecho que, en el corto plazo, para los paises productores de cafe es mas facil restringir la oferta para incrementar precios, que incrementarla para reducirlos. Ademas, se encuentra evidencia que el ajuste es mas rapido cuando las desviaciones del equilibrio son mayores. Los pronosticos que se obtienen a partir de los modelos de correccion de errores no lineales y asimetricos considerados en el trabajo, ofrecen una leve mejoria cuando se comparan con los pronosticos que resultan de un modelo de paseo aleatorio.

In der vorliegenden Arbeit wurden verschiedene Methoden der Milchleistungsprüfung (MLP) bei dreimaligem Melken getestet. Mit Hilfe von Modellentwicklungen und dem Test verschiedener Schätzverfahren wurde das Ziel verfolgt, den hohen Arbeitsaufwand zur MLP beim dreimal täglichen Melken zu reduzieren und trotzdem hinreichend genaue Prüfergebnisse zu garantieren. Dazu wurden Untersuchungen in zwei Milchviehbetrieben vorgenommen, die jeweils etwa 400 Kühe dreimal täglich in einem Intervall von 8:8:8 Stunden melkten. Es wurden am MLP-Tag zusätzlich zur obligatorischen Mischprobe aus allen drei Gemelken (Standardmethode) die Milchinhaltsstoffe jedes Einzelgemelkes analysiert und die Gemelksmengen erfasst. Die Untersuchungen ergaben, dass sich trotz gleicher Zwischenmelkzeiten die Mittelwerte sowohl der Milchmengen als auch der Inhaltsstoffe Fett und Eiweiß signifikant voneinander unterschieden. Dabei wiesen die Milchmengen und Inhaltsstoffe des Mittagsgemelkes die geringsten Unterschiede bzw. die höchsten Korrelationen zur Tagesgesamtleistung auf. Ein signifikanter Einfluss der Laktationsnummer und des Laktationsmonates auf die Schätzung der Tagesmilchmenge bzw. des Fett- und Eiweißgehaltes konnte nachgewiesen werden. Im Ergebnis des Vergleiches aller getesteten Schätzverfahren wurden für die Verwendung zweier Gemelke generell höhere Schätzgenauigkeiten erreicht als bei Einbeziehung lediglich eines Gemelkes in die Hochrechnung. Die alleinige Nutzung des Mittagsgemelkes ergab jedoch ähnlich hohe Schätzgenauigkeiten und erfordert einen deutlich geringeren Arbeitsaufwand. Die Methode der einfachen linearen Regression innerhalb von Klassen nach Laktation und Laktationsmonat führte zu den höchsten Übereinstimmungen in Bezug auf die wahren Tagesleistungen. Das Verfahren der MLP mit einem konstanten monatlichen Prüfgemelk (nur mittags) ergab höhere Genauigkeiten als ein monatlicher Wechsel der Probegemelke. Für die Praxis können folgende Empfehlungen gegeben werden: 1. Anhand der eigenen Ergebnisse ist ein Melkintervall von 8:8:8 Stunden anzustreben. 2. Unter den Bedingungen gleicher Zwischenmelkzeiten sollte die Probenahme aus dem Mittagsgemelk erfolgen, ohne das Prüfgemelk monatlich zu wechseln. 3. Die eigenen Auswertungen ergaben, dass sowohl der Eiweiß-, Laktose-, Zell- als auch der Harnstoffgehalt des Mittagsgemelkes hohe Übereinstimmungen zur Tagesgesamtleistung aufwiesen und demzufolge ohne Korrektur auf die Tagesleistung übertragen werden können. 4. Im Vergleich zu den anderen Inhaltsstoffen wurden für den Fettgehalt der Milch deutlich größere Variationen festgestellt. Der Fettgehalt des Mittagsgemelkes wies aber auch hier die höchsten Übereinstimmungen mit der Tagesgesamtleistung auf. Eine Korrektur zur Hochrechnung auf die Tagesleistung ist jedoch notwendig. 5. Obwohl zwischen der Milchmenge des Mittagsgemelkes und der Tagesgesamtleistung eine hohe Korrelation besteht, sollten bei vorhandener automatischer Milchmengenmessung alle Gemelke in die Prüfung einbezogen werden. Ist dies nicht möglich, bedarf auch die Milchmenge einer Korrektur zur Hochrechnung auf die Tagesleistung. Das aus dieser Arbeit abgeleitete alternative Verfahren der MLP bei dreimaligem Melken wurde indessen von der ADR anerkannt, vom ICAR genehmigt und ist offiziell zugelassen., Various methods of milk recording for 3-times milking per day have been tested in this study. The aim of the work was to expand models for estimating daily yield from only one or two milkings per cow and day. Comparisons of different models were made to select the highest accuracy of prediction. But also practicability was taken into consideration. Investigations were made on two dairy farms each milking 400 cows 3-times daily with an milking interval of 8:8:8 hours. In addition to a mixture of all three milking samples (obligatory sample for the standard method) a separate sample from each of the three milkings was taken and analysed. Single milk yields were registered, too. The results documented significant differences between yields of milk and contents of fat and protein per milking despite equal milking intervals. Milk yields were highest at morning milking and lowest in the evening. The lowest differences in relation to the whole daily yield were found for the midday milking. This milking also had the highest correlation with daily yield. A significant influence of number and stage of lactation was established for the estimation of daily milk yield and fat and protein content, respectively. In the result of the comparison between all estimation methods generally better accuracies have been found for including two out of three milkings per day than including only one milking for estimating daily yield. But using only midday milking proved similar high precision and requires smaller expense of work and cost. Method of simple linear regression within classes of lactation number and lactation stage led to the highest correspondences in relation to the true daily yield. The testing method which included only midday samples each month (without changing) resulted in higher accuracies than a monthly change between all three milkings (morning/midday/evening). The following recommendations can be given for practice: 1. On the basis of results a milking interval of 8:8:8 hours is to prefer. 2. Under conditions of equal times between milkings samples should be taken from midday milking. 3. The corrected method with midday milking has to be used. Each month only midday milking has to be sampled and analysed, without an alternating sampling of milkings. 4. The results showed that under conditions of equal milking intervals there were high correspondences between contents of protein, lactose, somatic cell count, and urea of the midday sample and the mixed sample of all milkings per day. To estimate daily yields, here no correction is necessary. 5. The content of fat varied extremely within cow and day in comparison with other components. Midday milking showed highest correspondences with daily yield, too. But here a correction is necessary. 6. Even though there is a high correlation between milk yield of the midday milking and the whole yield of the day it is advisable to include all milking yields of the test day if automatic equipment for measuring milk yield is available. Otherwise a correction of milk yield of midday milkings is necessary, too. The in this study recommended alternative method of milk recording under conditions of 3-times daily milking is meanwhile accepted by ICAR as well as registered in Germany.

Proceedings on CD-ROM.; International audience; In spite of the fact that disaggregate modelling has undergone considerable development in the last twenty years, many studies are still based on aggregate modelling. In France, for example, aggregate models are still in much more common use than disaggregate models, even for modal split. The estimation of aggregate models is still therefore an important issue.In France, for most studies it is possible to use behavioural data from household surveys, which are conducted every ten years in most French conurbations. These household surveys provide data on the socioeconomic characteristics both of individuals and the households to which they belong and data on modal choice for all the trips made the day before the survey. The sampling rate is generally of 1% of the population, which gives about 50,000 trips for a conurbation of 1 million inhabitants. However, matrices that contain several hundred rows and columns are frequently used. We therefore have to construct several modal matrices that contain more than 10,000 cells (in the case of a small matrix with only 100 rows) with less than 50,000 trips (to take the above example). Obviously, the matrices will contain a large number of empty cells and the precision of almost all the cells will be very low. It is consequently not possible to estimate the model at this level of zoning.The solution which is generally chosen is to aggregate zones. This must comply with two contradictory objectives:- the number of zones must be as small as possible in order to increase the number of surveyed trips that can be used during estimation and hence the accuracy of the O-D matrices for trips conducted on each mode;- the zones must be as small as possible in order to produce accurate data for the explanatory variables such as the generalized cost for each of the transport modes considered. When the size of the zone increases, it is more difficult to evaluate the access and regress time for public transport and there are several alternative routes with different travel times between each origin zone and each destination. Therefore more uncertainty is associated with the generalized cost that represents the quality of service available between the two zones. The generally adopted solution is to produce a weighted average of all the generalized costs computed from the most disaggregated matrix. However, there is no guarantee that this weighted mean will be accurate for the origin-destination pair in question.When the best compromise has been made, some of the matrix cells are generally empty or suffer from an insufficient level of precision. To deal with this problem we generally keep only the cells for which the data is sufficiently precise by selecting those cells in which the number of surveyed trips exceeds a certain threshold. However, this process involves rejecting part of the data which cannot be used for estimation purposes. When a fairly large number of zones is used, the origin destination pairs which are selected for the estimation of the model mainly involve trips that are performed in the centre of the conurbation or radial trips between the centre and the suburbs. These origin-destination pairs are also those for which public transport's share is generally the highest. The result is to reduce the variance of the data and therefore the quality of the estimation.To cope with this problem we propose a different aggregation process which makes it possible to retain all the trips and use a more disaggregate zoning system. The principle of the method is very simple. We shall apply the method to the model most commonly used for modal split, which is the logit model. When there are only two modes of transport, the share of each mode is obtained directly from the difference in the utility between the two modes with the logit function. We can therefore aggregate the origin-destination pairs for which the difference between the utility of the two modes is very small in order to obtain enough surveyed trips to ensure sufficient data accuracy. This process is justified by the fact that generally the data used to calculate the utility of each mode is as accurate or even more accurate at a more disaggregate level of zoning. The problem with this method is that the utility function coefficients have to be estimated at the same time as the logit model. An iterative process is therefore necessary. The steps of the method are summarised below:- selection of initialization values for the utility function coefficients for the two transport modes in order to intitialize the iteration process. These values can, for example, be obtained from a previous study or calibration performed according to the classical method described in Section 1.2;- the utility for each mode is computed on the basis of the above coefficients, followed by the difference in the utility for each O-D pair in the smallest scale zoning system for which explanatory variables with an adequate level of accuracy are available (therefore with very limited zonal aggregation or even none at all);- the O-D pairs are classified on the basis of increasing utility difference;- the O-D pairs are then aggregated. This is done on the basis of closeness of utility difference. The method involves taking the O-D link with the smallest utility difference then combining it with the next O-D pair (in order of increasing utility difference). This process is continued until the number of surveyed trips in the grouping is greater than a threshold value that is decided on the basis of the level of accuracy that is required for trip flow estimation. When this threshold is reached the construction of the second grouping is commenced, and so on and so forth until each O-D pair has been assigned to a group;- for each new class of O-D pairs it is necessary to compute the values of the explanatory variables which make up the utility functions for each class. This value is obtained on the basis of the weighted average of the values for each O-D pair in the class;- a new estimation of the utility function coefficients.This process is repeated until the values of the utility function coefficients converge. We have tested this method for the Lyon conurbation with data from the most recent household travel survey conducted in 1995/96. We have conducted a variety of tests in order to identify the best application of the method and to test the stability of the results. It would seem that this method always produces better results than the more traditional method that involves zoning aggregation. The paper presents both the methodology and the results obtained from different aggregation methods. In particular, we analyse how the choice of zoning system affects the results of the estimation.

Delivering software on time, within budget, and to an agreed level of quality is crucial for the business reputation and competitiveness of many organisations. Accurate estimates are essential for a better project planning, tracking, and control and pave the way for successful product delivery. This calls for support in software cost estimation, since many software companies are working within tight schedules and finish their projects behind schedule and budget, if they finish them at all. This is because the estimation of cost for software projects leads to many practical measurement and modelling difficulties. To overcome limitations, this research proposes an enhancement of the method Optimised Set Reduction (OSR) to solve estimation problems. The goal is to provide an estimation method that overcomes the main drawbacks of other methods and that produces models with an accuracy comparable to other commonly used models. The OSR method is originally defined to solve classification problems and is based on machine learning and robust statistics (Briand et al., 1992). It exploits the rigor of statistical modelling and still generates easy-to-interpret, rule-based models.