Quantification of different effects occurring during fatigue tests on bituminous mixtures

Quantification of different effects (nonlinearity, heating, thixotropy, and fatigue) occurring during fatigue tests on bituminous mixtures is presented in this paper. A focus is given on the nonlinearity phenomenon. Continuous fatigue tests and a test with specific protocol (called fatigue tests to estimate biasing effects) were performed in tension/compression mode on cylindrical samples of the same material. The analysis of results reveals that reversible effects (nonlinearity, heating, and thixotropy) are important (more than 90% decrease at 100,000 cycles for a strain amplitude of 100 μm/m at 10 Hz) and cannot be ignored when interpreting classical fatigue tests. The nonlinearity effects respect the time‐temperature superposition principle, and they are more pronounced at “high” temperature (at the same frequency). Direction of nonlinearity curve in the Cole‐Cole axes is shown to be independent of temperature and frequency for the considered range.     

Effects of club size in the provision of public goods. Network and congestion effects in the case of the French municipalities

The article formalizes and measures the impact of club size on the quality of the public good provided to its members. Under a general framework we describe various functional forms that allow either network or crowding effects. Mechanisms of provision are that of a political process in which both the demand and the supply sides are considered. Estimations use the whole set of French municipalities. The supply model performs better than the demand model in the case of small municipalities, while for large cities the demand model has higher explanatory power. In so far as impact of city size on the quality of club goods is concerned, crowding does appear, but it does so in different patterns. For small towns marginal congestion first decreases then increases with population. Marginal congestion is decreasing for cities of intermediate size. For larger cities no significant effects are observed. Received: 27 June 2000 / Accepted: 20 August 2001 RID="*" ID="*" We have received particularly helpful comments from the editor-in-chief and two anonymous referees. We also thank Danièle Moret-Bailly for her friendly computational assistance.     

Object-based fusion for urban tree species classification from hyperspectral,panchromatic and nDSM data

This study aims at identifying the best object-based fusion strategy that takes advantage of the complementarity of several heterogeneous airborne data sources for improving the classification of 15 tree species in an urban area (Toulouse, France). The airborne data sources are: hyperspectral Visible Near-Infrared (160 spectral bands, spatial resolution of 0.4 m) and Short-Wavelength Infrared (256 spectral bands, 1.6 m), panchromatic (14 cm), and a normalized Digital Surface Model (12.5 cm). Object-based feature and decision level fusion strategies are proposed and compared when applied to a reference site where the species are previously identified during ground truth collection. This allows the best fusion strategy to be selected with a view to introducing the method in an automatic process (tree crown delineation and species classification) on a test site, independent of the reference site used for learning. In particular, a decision level fusion is selected: based on the Support Vector Machine algorithm, Visible Near-Infrared and Short-Wavelength Infrared classifications use Minimum Noise Fraction components at the original spatial resolution, whereas panchromatic and normalized Digital Surface Model classifications use, respectively, Haralick’s and structural features computed at the object scale. After the computation of a decision profile for each source at the object level based on the classification algorithms’ membership probabilities, these decision profiles are combined and a decision rule is applied to predict the species. Focusing on the reference site, the Visible Near-Infrared exhibits the best performances with F-score values higher than 60% for 13 species out of 15. The Short-Wavelength Infrared is the most powerful for three species with F-score greater than 60% for seven common species with the Visible Near-Infrared. The panchromatic and normalized Digital Surface Model contribute marginally. The best fusion strategy (decision fusion) does not improve significantly the overall accuracy with 77% (kappa = 74%) against 75% (kappa = 72%) for the Visible Near-Infrared but in general, it improves the results for cases where complementarities have been observed. When applied to the test site and assessed for the two majority species (Tilia tomentosa and Platanus x hispanica), the selected approach gives consistent results with an overall accuracy of 63% against 55% for the Visible Near-Infrared.     

Statically detecting use after free on binary code

We present GUEB a static tool detecting Use after Free vulnerabilities on disassembled code. This tool has been evaluated on a real vulnerability in the ProFTPD application (CVE-2011-4130).     

PD-L1 Expression in 65 Conjunctival Melanomas and Its Association with Clinical Outcome

Conjunctival melanoma (CM) iss a rare and aggressive tumour that is increasing in frequency. The prognostic value of PD-L1 expression, alone or in combination with CD8 and PD-1 expression and the BRAF and NRAS status, has not been determined in CM to date. We evaluated the expression of PD-L1, CD8, PD-1 in CM and investigated whether there was an association between the expression of these markers and the BRAF and NRAS molecular profile as well as some clinico-pathological criteria. A total of sixty-five CM were assessed for PD-L1, PD-1, and CD8 expression by immunohistochemistry (IHC) and for BRAF and NRAS genomic alterations using molecular biology techniques and anti-BRAF and anti-NRAS antibodies. PD-L1 expression in tumour cells (TC) was very low or absent but detected in tumour-infiltrating immune cells (IC). A correlation was observed between the expression of PD-L1, CD8, and PD-1 in IC. No correlation between PD-L1 expression (in tumour and/or immune cells) and BRAF or NRAS mutations was observed. PD-L1 expression in IC correlated with a higher pTNM stage and PD-L1 expression in TC with worse disease-specific survival. PD-L1 expression is a potential prognostic biomarker that correlates with poor prognosis in CM patients.     

Evaluation of tone mapping operators in night-time virtual worlds

The subjective quality of a virtual world depends on the quality of displayed images. In the present paper, we address a technical aspect of image quality in virtual environments. Due to the recent development of high dynamic range (HDR) imaging in computer graphics applications, tone mapping operators (TMO) are needed in the graphic pipeline, and their impact on the final image quality needs to be tested. Previous evaluations of such operators have emphasized the fact that the specific merit of a given operator may depend on both the scene and the application. The dynamic behavior of tone mapping operators was not tested before, and we have designed two psychophysical experiments in order to assess the relevance of various TMO for a specific class of virtual worlds, outdoor scenes at night and an interactive application, to explore an outdoor virtual world at night. In a first experiment, 5 HDR video clips were tone-mapped using 8 operators from the literature, resulting in 40 videos. These 40 videos were presented to 14 subjects, which were asked to rate their realism. However, the subject’s evaluation was not a direct comparison with the HDR videos. In a second experiment, 9 HDR photographs of urban scenes at night were tone-mapped with the same 8 operators. The resulting 72 photographs were presented to 13 subjects, at the location where the photographs were taken. The subjects were asked to rate the realism of each tone-mapped image, displayed on a laptop, with respect to the physical scene they experienced. The first experiment emphasized the importance of modeling the temporal visual adaptation for a night-time application.     

Optimization of occupancy rate in dial-a-ride problems via linear fractional column generation

In this paper, we consider a dial-a-ride problem where the objective is to maximize the passenger occupancy rate. The problem arises from an on-demand transportation system developed in a rural zone in France, where the objective of encouraging people meeting is pursued. We address the solution of the problem with a column generation approach, applied to a set partitioning formulation where the objective function is fractional. Based on the literature on linear fractional programming, two methods are developed to deal with this fractional objective. Experiments permit to compare these two approaches and to evaluate the impact of the new objective compared to a standard min-cost or min-time optimization.     

Verification of Use of Peak Area for Quantitative Differential Thermal Analysis

The amount of reacting material in a sample investigated by differential thermal analysis can be determined from the peak area according to the Boersma equation, which accounts for heat flow through sample and thermocouple wires. This relation has been checked by experiment and it has been found that the use of different thermocouples for the calibrations may lead to variations of about 30%. The values obtained for heat transfer through a sample and thermocouple have been checked by comparison of computations and observation of base-line offset at the beginning of a run and exponential decay of the amount of heat dissipating out of a sample. It is shown that according to the equation it is not the total amount of reacting material that determines the peak area but merely the density of the material near the thermocouple. The sensitivity of the method for quantitative analysis is discussed in relation to the possible variations in the factors involved, namely, density and heat conductivity of the sample and heat transfer through the thermocouple.     

Confidence limits for Neyman type A-distributed events

The Neyman type A distribution, a generalised, 'contagious' Poisson distribution, finds application in a number of disciplines such as biology, physics and economy. In radiation biology, it best describes the distribution of chromosomal aberrations in cells that were exposed to neutrons, alpha radiations or heavy ions. Intriguingly, no method has been developed for the calculation of confidence limits (CLs) of Neyman type A-distributed events. Here, an algorithm to calculate the 95% CL of Neyman type A-distributed events is presented. Although it has been developed in response to the requirements of radiation biology, it can find application in other fields of research. The algorithm has been implemented in a PC-based computer program that can be downloaded, free of charge, from www.pu.kielce.pl/ibiol/neta.     

CABAS: a freely available PC program for fitting calibration curves in chromosome aberration dosimetry

The aim of biological dosimetry is to estimate the dose and the associated uncertainty to which an accident victim was exposed. This process requires the use of the maximum-likelihood method for fitting a calibration curve, a procedure that is not implemented in most statistical computer programs. Several laboratories have produced their own programs, but these are frequently not user-friendly and not available to outside users. We developed a software for fitting a linear-quadratic dose-response relationship by the method of maximum-likelihood and for estimating a dose from the number of aberrations observed. The program called as CABAS consists of the main curve-fitting and dose estimating module and modules for calculating the dose in cases of partial body exposure, for estimating the minimum number of cells necessary to detect a given dose of radiation and for calculating the dose in the case of a protracted exposure. The program is freely available at http://www.pu.kielce.pl/ibiol/cabas.