Contracts play an important role in business management where relationships among different parties are dictated by legal rules. Electronic contracts have emerged mostly due to technological advances and electronic trading between companies and customers. New challenges have then arisen to guarantee reliability among the stakeholders in electronic negotiations. In this scenario, automatic verification of electronic contracts appeared as an imperative support, specially the conflict detection task of multi-party contracts. The problem of checking contracts has been largely addressed in the literature, but there are few, if any, methods and practical tools that can deal with multi-party contracts using a contract language with deontic and dynamic aspects as well as relativizations, over the same formalism. In this work we present an automatic checker for finding conflicts on multi-party contracts modeled by an extended contract language with deontic operators and relativizations. Moreover a well-known case study of sales contract is modeled and automatically verified by our tool. Further, we performed practical experiments in order to evaluate the efficiency of our method and the practical tool.
This work presents a dominant point detector. The angles of the contour are characterized through local entropy produced by a rotationally symmetric smoothing. The proposed scheme uses a punctual multi-scale approach in which only the candidates are analyzed in higher scales. To preserve the angle-entropy relationship in higher scales, we propose a smoothing kernel which presents special features that ensure its steepness in every scale. It is built from the sum of two Gaussians with different openings resembling center-surround receptive fields. The outputs of the proposed method are confronted to a ground-truth found in the literature, and to popular boundary based corner detectors that used the same set of images. Results reveal that the proposed detector performs extremely well. 相似文献
The main objective of using cutting fluids in machining operations is the reduction of temperature in the cutting region to increase tool life. However, the advantages offered by cutting fluids have been strongly debated because of their negative effects on the economic aspect, the environment and the health of workers using them. A trend to solve these problems is cutting without fluid, a method named dry cutting, which has been made possible due to technological innovations. This work aims to seek conditions in which dry cutting is satisfactory compared with the flood of fluid (called here wet cutting) usually used. Aiming at this goal, several experiments were carried out varying parameters such as cutting speed, feed, depth of cut and tool material in rough turning of ABNT 1045 steel in dry and wet cutting. The analysis of the results showed that wet turning is, as expected, better for tool life. The second conclusion is that dry cutting cannot be used with large depth of cut. But the main conclusion is that, if the tool material is changed to a more wear resistant one, dry cutting can be used with results very similar to those obtained with a flood of fluid. 相似文献
This paper proposes a novel computer vision approach that processes video sequences of people walking and then recognises
those people by their gait. Human motion carries different information that can be analysed in various ways. The skeleton
carries motion information about human joints, and the silhouette carries information about boundary motion of the human body.
Moreover, binary and gray-level images contain different information about human movements. This work proposes to recover
these different kinds of information to interpret the global motion of the human body based on four different segmented image
models, using a fusion model to improve classification. Our proposed method considers the set of the segmented frames of each
individual as a distinct class and each frame as an object of this class. The methodology applies background extraction using
the Gaussian Mixture Model (GMM), a scale reduction based on the Wavelet Transform (WT) and feature extraction by Principal
Component Analysis (PCA). We propose four new schemas for motion information capture: the Silhouette-Gray-Wavelet model (SGW)
captures motion based on grey level variations; the Silhouette-Binary-Wavelet model (SBW) captures motion based on binary
information; the Silhouette–Edge-Binary model (SEW) captures motion based on edge information and the Silhouette Skeleton
Wavelet model (SSW) captures motion based on skeleton movement. The classification rates obtained separately from these four
different models are then merged using a new proposed fusion technique. The results suggest excellent performance in terms
of recognising people by their gait. 相似文献
Water Resources Management - Increasing global trends in time series of annual maximum daily streamflow (AMX) raise the concern that the safety of dams and other sensitive structures is... 相似文献
Composites of Al2O3/ZrO2 (containing 25, 50, and 75 vol% ZrO2) were prepared by mixing Al2O3 and ZrO2 suspensions. The microstructural control via two-step sintering (TSS) was the main objective of this work. For this purpose, different sintering curves were constructed, aiming to achieve the best temperature combination for the sintering steps that provides higher density and finer microstructure. The results were compared with single-step sintering (SSS). Furthermore, microhardness and fracture toughness were measured for the best TSS specimens under each composition. The results showed that the high densities were obtained, and the reduction of grain size was greater than 40% for two-step sintered specimens, compared to SSS ones. Consequently, microhardness values increased. However, fracture toughness values remained unchanged. 相似文献
In this work three mathematical models for methane steam reforming in membrane reactors were developed. The first one is a
steady state, non isothermal, non isobaric and one dimensional model derived from material and energy balances and validated
using experimental data from the literature. It is referred as full model. The influence of two different intrinsic kinetics
available, as well as, the influence of five important parameters on methane conversion (XCH4_{\mathrm{CH}_{4}}) and hydrogen recovery (YH2_{\mathrm{H}_{2}}) were parametrically evaluated through simulations. The second model, referred as meta-model, was obtained though the response
surface technique. This meta-model was included into a constrained optimization problem solved using NPSOL. The third model,
referred as a simplified model, takes into account only mass balances from the full model. Using this model, a gradient based
method (DIRCOL) was used to perform the optimization of the sum of methane conversion and hydrogen recovery. High methane
conversions and hydrogen recoveries were reached through these methodologies. 相似文献
Abstract The hydroxymethylation of Acetosolv lignin from sugarcane bagasse was studied at 40°C between 0.25 and 8 h by Fourier-transformed infrared spectroscopy (FTIR). Principal Component Analysis (PCA) of the spectra has determined that addition of formaldehyde to the lignin fragments was completed within 4 h. After that time, only condensation of the fragments occurs, leading to a resol-type crosslinked resin. PCA performed in selected regions of the FTIR spectra showed that the same results are also obtained for the stretching region of O-H and C-H within the range from 2800 to 3800 cm?1, which is not usually considered in the spectroscopic evaluations of modified lignins. 相似文献
In this study, conducting blends of poly(acrylonitrile-butadiene-styrene) and polyaniline doped with dodecylbenzene sulfonic acid were prepared by solution blending. In order to understand the electrical conduction mechanism of the samples, DC electrical conductivity measurements of the blends were carried out in the temperature range of 80–320 K. The experimental results fit well with Mott's model of three-dimensional variable range hopping conduction. The values of Mott's temperature, density of states at the Fermi energy, average hopping distance and barrier height for the composites were calculated and presented. 相似文献
Responses to global warming will be determined by social and political factors as much as by science. During the 1980s, concern about climate change has been encouraged by developments in the international arena and in the energy sector. There are some similarities between the responses to this new problem and those to the oil crises of the 1970s. Similar intellectual tools are being used to understand the appropriateness of different courses of action while there must be doubts about the durability of public and political interest. At the same time costs could fall disproportionately on different countries, particularly those in the developing world. 相似文献