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91.
Tuyet Le-Anh Jorge Villalobos Jacky Estublier 《Electronic Notes in Theoretical Computer Science》2003,82(5):164
Reusability is the holly grail of software engineers. But reusability requires powerful composition mechanisms since the pieces to compose have no reason to match perfectly. Unfortunately, the composition mechanisms available today, mostly method call and component assembly are rather primitive. This paper shows what is the current state of the art in software composition, showing that there is little composition flexibility at code level, even using workflow approaches.The approach presented here claims that composition requires reasoning at different levels of abstraction. Workflow support is first decoupled from real tools, using abstract tool modeling. Contracts have been included to increase the independence between process and tools. Then, we have introduced conceptual abstractions linked by contract to real tools. Finally, we show that it is possible to define composition at the abstract level.The resulting system shows very high adaptability capabilities. Experience shows, however, that to be practical, this approach requires adapted framework and specialized tools. This paper shows the experience gained in implementing many versions of such a framework. The current system is currently in industrial use. 相似文献
92.
Gilles Celeux Author Vitae Author Vitae Jorge Marques Author Vitae 《Pattern recognition》2004,37(9):1841-1853
Many recent tracking algorithms rely on model learning methods. A promising approach consists of modeling the object motion with switching autoregressive models. This article is involved with parametric switching dynamical models governed by an hidden Markov Chain. The maximum likelihood estimation of the parameters of those models is described. The formulas of the EM algorithm are detailed. Moreover, the problem of choosing a good and parsimonious model with BIC criterion is considered. Emphasis is put on choosing a reasonable number of hidden states. Numerical experiments on both simulated and real data sets highlight the ability of this approach to describe properly object motions with sudden changes. The two applications on real data concern object and heart tracking. 相似文献
93.
Development of an Active Thermoplastic Film with Oxygen Scavengers Made of Activated Carbon and Sodium Erythorbate 下载免费PDF全文
Ronald Joven Angela Garcia Andrea Arias Jorge Medina 《Packaging Technology and Science》2015,28(2):113-121
An active thermoplastic film made of low‐density polyethylene (LDPE) filled with oxygen scavengers made of powdered activated carbon (PAC) impregnated with sodium erythorbate (SE) was developed for packaging applications. Initial tests indicated that the impregnation of PAC with SE enhanced the heat resistance of SE, thereby allowing processing at temperatures typical of LDPE manufacturing. Subsequently, LDPE films with PAC/SE particles were manufactured in coupons that represented a typical juice package, and experiments indicated that these films absorbed 3.57 mg of oxygen in 11 days. This amount corresponded to 80% the concentration of oxygen in the headspace of the package. Furthermore, findings indicated that active particles alone have 10 times higher oxygen absorption capacity than the active LDPE film. Finally, the physical properties of the film were characterized by microscopy where oxygen scavengers showed a good dispersion within the matrix. However, 20 wt.% of these active particles decreased tensile strength of the film by 53%. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
94.
Camila Reyes Estefanía Nova-Lamperti Daniel Duran-Sandoval Daniela Rojas Jorge Gajardo Enrique Guzman-Gutierrez Camila Bustos-Ruiz Valeska Ormazbal Felipe A. Zúiga Carlos Escudero Claudio Aguayo 《International journal of molecular sciences》2022,23(13)
Oxidized low-density lipoprotein (ox-LDL) is the most harmful form of cholesterol associated with vascular atherosclerosis and hepatic injury, mainly due to inflammatory cell infiltration and subsequent severe tissue injury. Lox-1 is the central ox-LDL receptor expressed in endothelial and immune cells, its activation regulating inflammatory cytokines and chemotactic factor secretion. Recently, a Lox-1 truncated protein isoform lacking the ox-LDL binding domain named LOXIN has been described. We have previously shown that LOXIN overexpression blocked Lox-1-mediated ox-LDL internalization in human endothelial progenitor cells in vitro. However, the functional role of LOXIN in targeting inflammation or tissue injury in vivo remains unknown. In this study, we investigate whether LOXIN modulated the expression of Lox-1 and reduced the inflammatory response in a high-fat-diet mice model. Results indicate that human LOXIN blocks Lox-1 mediated uptake of ox-LDL in H4-II-E-C3 cells. Furthermore, in vivo experiments showed that overexpression of LOXIN reduced both fatty streak lesions in the aorta and inflammation and fibrosis in the liver. These findings were associated with the down-regulation of Lox-1 in endothelial cells. Then, LOXIN prevents hepatic and aortic tissue damage in vivo associated with reduced Lox-1 expression in endothelial cells. We encourage future research to understand better the underlying molecular mechanisms and potential therapeutic use of LOXIN. 相似文献
95.
The development and computational implementation, on a multibody dynamics environment, of a constitutive relation to model
bushing elements associated with mechanical joints used in the models of road and rail vehicles is presented here. These elements
are used to eliminate vibrations in vehicles, due to road irregularities, to allow small misalignment of axes, to reduce noise
from the transmission, or to decrease wear of the mechanical joints. Bushings are made of a special rubber, used generally
in energy dissipation, which presents a nonlinear viscoelastic relationship between the forces and moments and their corresponding
displacements and rotations. In the methodology proposed here a finite element model of the bushing is developed in the framework
of the finite element code ABAQUS to obtain the constitutive relations of displacement/rotation versus force/moment for different
loading cases. The bushing is modeled in a multibody code as a nonlinear restrain that relates the relative displacements
between the bodies connected with the joint reaction forces, and it is represented by a matrix constitutive relation. The
basic ingredients of the multibody model are the same vectors and points relations used to define kinematic constraints in
any multibody formulation. One particular, and relevant, characteristic of the formulation now presented is its ability to
represent standard kinematic joints, clearance, and bushing joints just by defining appropriate constitutive relations. Spherical,
revolution, cylindrical, and translational bushing joints are modeled, implemented, and demonstrated through the simulation
of two multibody models of a road vehicle, one with perfect kinematic joints for the suspension sub-systems, and other with
bushing joints. The tests conducted include an obstacle avoidance maneuver and a vehicle riding over bumps. It is shown that
the bushing models for vehicle multibody models proposed here are accurate and computationally efficient so that they can
be included in the vehicle models leading reliable simulations. 相似文献
96.
This paper proposes a sliding window approach, whose length and time shift are dynamically adaptable in order to improve model confidence, speed and segmentation accuracy in human action sequences. Activity recognition is the process of inferring an action class from a set of observations acquired by sensors. We address the temporal segmentation problem of body part trajectories in Cartesian Space in which features are generated using Discrete Fast Fourier Transform (DFFT) and Power Spectrum (PS). We pose this as an entropy minimization problem. Using entropy from the classifier output as a feedback parameter, we continuously adjust the two key parameters in a sliding window approach, to maximize the model confidence at every step. The proposed classifier is a Dynamic Bayesian Network (DBN) model where classes are estimated using Bayesian inference. We compare our approach with our previously developed fixed window method. Experiments show that our method accurately recognizes and segments activities, with improved model confidence and faster convergence times, exhibiting anticipatory capabilities. Our work demonstrates that entropy feedback mitigates variability problems, and our method is applicable in research areas where action segmentation and classification is used. A working demo source code is provided online for academical dissemination purposes, by requesting the authors. 相似文献
97.
Fluorescent protein tomography scanner for small animal imaging 总被引:2,自引:0,他引:2
Zacharakis G Ripoll J Weissleder R Ntziachristos V 《IEEE transactions on medical imaging》2005,24(7):878-885
Microscopy of fluorescent proteins has enabled unprecedented insights into visualizing gene expression in living systems. Imaging deeper into animals, however, has been limited due to the lack of accurate imaging methods for the visible. We present a novel system designed to perform tomographic imaging of fluorescent proteins through whole animals. The tomographic method employed a multiangle, multiprojection illumination scheme, while detection was achieved using a highly sensitive charge-coupled device camera with appropriate filters. Light propagation was modeled using a modified solution to the diffusion equation to account for the high absorption and high scattering of tissue at the visible wavelengths. We show that the technique can quantitatively detect fluorescence with sub millimeter spatial resolution both in phantoms and in tissues. We conclude that the method could be applied in tomographic imaging of fluorescent proteins for in vivo targeting of different diseases and abnormalities. 相似文献
98.
Jorge Lopez-Tello Maria Angeles Jimenez-Martinez Esteban Salazar-Petres Ritik Patel Amy L. George Richard G. Kay Amanda N. Sferruzzi-Perri 《International journal of molecular sciences》2022,23(11)
Pregnancy is characterized by adaptations in the function of several maternal body systems that ensure the development of the fetus whilst maintaining health of the mother. The renal system is responsible for water and electrolyte balance, as well as waste removal. Thus, it is imperative that structural and functional changes occur in the kidney during pregnancy. However, our knowledge of the precise morphological and molecular mechanisms occurring in the kidney during pregnancy is still very limited. Here, we investigated the changes occurring in the mouse kidney during pregnancy by performing an integrated analysis involving histology, gene and protein expression assays, mass spectrometry profiling and bioinformatics. Data from non-pregnant and pregnant mice were used to identify critical signalling pathways mediating changes in the maternal kidneys. We observed an expansion of renal medulla due to proliferation and infiltration of interstitial cellular constituents, as well as alterations in the activity of key cellular signalling pathways (e.g., AKT, AMPK and MAPKs) and genes involved in cell growth/metabolism (e.g., Cdc6, Foxm1 and Rb1) in the kidneys during pregnancy. We also generated plasma and urine proteomic profiles, identifying unique proteins in pregnancy. These proteins could be used to monitor and study potential mechanisms of renal adaptations during pregnancy and disease. 相似文献
99.
María Irene Cerezo-Corts Juan Germn Rodríguez-Castillo Dulce Adriana Mata-Espinosa Estela Isabel Bini Jorge Barrios-Payan Zyanya Lucia Zatarain-Barrn Juan Manuel Anzola Fernanda Cornejo-Granados Adrian Ochoa-Leyva Patricia Del Portillo Martha Isabel Murcia Rogelio Hernndez-Pando 《International journal of molecular sciences》2022,23(9)
100.
Jorge Barrios Alain Piétrus Gonzalo Joya Aymée Marrero Héctor de Arazoza 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2013,17(2):239-253
In this paper we deal with the application of differential inclusions to modeling nonlinear dynamical systems under uncertainty in parameters. In this case, differential inclusions seem to be better suited to modeling practical situations under uncertainty and imprecision than formulations by means of fuzzy differential equations. We develop a practical algorithm to approximate the reachable sets of a class of nonlinear differential inclusion, which eludes the computational problems of a previous set-valued version of the Heun’s method. Our algorithm is based on a complete discretization (time and state space) of the differential inclusion and it suits hardware features, handling the memory used by the method in a controlled fashion during all iterations. As a case of study, we formulate a differential inclusion to model an epidemic outbreak of dengue fever under Cuban conditions. The model takes into account interaction of human and mosquito populations as well as vertical transmission in the mosquito population. It is studied from the theoretical point of view to apply the Practical Algorithm. Also, we estimate the temporal evolution of the different human and mosquito populations given by the model in the Dengue 3 epidemic in Havana 2001, through the computation of the reachable sets using the Practical Algorithm. 相似文献