Leptin and its soluble receptor (sOB-R) are important to regulation of body composition but there are no data on the developmental
variations in these plasma variables and their relationship with body composition measurements, 相似文献
The efficient application of current methods of shadow detection in video is hindered by the difficulty in defining their parameters or models and/or their application domain dependence. This paper presents a new shadow detection and removal method that aims to overcome these inefficiencies. It proposes a semi-supervised learning rule using a new variant of co-training technique for shadow detection and removal in uncontrolled scenes. The new variant both reduces the run-time through a periodical execution of a co-training process according to a novel temporal framework, and generates a more generic prediction model for an accurate classification. The efficiency of the proposed method is shown experimentally on a testbed of videos that were recorded by a static camera and that included several constraints, e.g., dynamic changes in the natural scene and various visual shadow features. The conducted experimental study produced quantitative and qualitative results that highlighted the robustness of our shadow detection method and its accuracy in removing cast shadows. In addition, the practical usefulness of the proposed method was evaluated by integrating it in a Highway Control and Management System software called RoadGuard. 相似文献
Fast and accurate moving object segmentation in dynamic scenes is the first step in many computer vision applications. In this paper, we propose a new background modeling method for moving object segmentation based on dynamic matrix and spatio-temporal analyses of scenes. Our method copes with some challenges related to this field. A new algorithm is proposed to detect and remove cast shadow. A comparative study by quantitative evaluations shows that the proposed approach can detect foreground robustly and accurately from videos recorded by a static camera and which include several constraints. A Highway Control and Management System called RoadGuard is proposed to show the robustness of our method. In fact, our system has the ability to control highway by detecting strange events that can happen like vehicles suddenly stopped in roads, parked vehicles in emergency zones or even illegal conduct such as going out from the road. Moreover, RoadGuard is capable of managing highways by saving information about the date and time of overloaded roads. 相似文献
The detection of moving objects is a crucial step for many video surveillance applications whether using a visible camera (VIS) or an infrared (IR) one. In order to profit from both types, several fusion methods were proposed in the literature: low-level fusion, medium-level fusion and high-level fusion. The first one is the most used for moving objects’ detection in IR and VIS spectra. In this paper, we present an overview of the different moving object detection methods in IR and VIS spectra and a state of the art of the low-level fusion techniques. Moreover, we propose a new method for moving object detection using low-level fusion of IR and VIS spectra. In order to evaluate quantitatively and qualitatively our proposed method, three series of experiments were carried out using two well-known datasets namely “OSU Color-Thermal Database” and “INO-Database”; the results of these evaluations show promising results and demonstrate the effectiveness of the proposed method. 相似文献
This paper reports a discrimination study based on the physico‐chemical characteristics, fatty acids and profile of volatile compounds of the seeds from seven date palm varieties (Phoenix dactylifera L.) grown in Tunisia. Date seeds contained 10.49–14.76% moisture; 6.28–11.2% fat (on a dry weight basis); 2.67–12.85% protein; 0.91–6.06% reducing sugar; 0.61–2.98% sucrose and 0.97–1.17% ash. Gas liquid chromatography revealed that the oil fraction of the date palm seeds contained eighteen fatty acids, with oleic acid (30.77–42.50%) and lauric acid (18.51–27.48%) as the main unsaturated and saturated ones. Volatile profile showed differences among varieties. In total, forty‐five compounds were identified, mainly alcohols, aldehydes and unsaturated hydrocarbons ones. This study provides evidence that the seeds of date may be a potential source of valuable nutrients with interesting functionality. 相似文献
Face recognition has become an accessible issue for experts as well as ordinary people as it is a focal non-interfering biometric modality. In this paper, we introduced a new approach to perform face recognition under varying facial expressions. The proposed approach consists of two main steps: facial expression recognition and face recognition. They are two complementary steps to improve face recognition across facial expression variation. In the first step, we selected the most expressive regions responsible for facial expression appearance using the Mutual Information technique. Such a process helps not only improve the facial expression classification accuracy but also reduce the features vector size. In the second step, we used the Principal Component Analysis (PCA) to build EigenFaces for each facial expression class. Then, a face recognition is performed by projecting the face onto the corresponding facial expression Eigenfaces. The PCA technique significantly reduces the dimensionality of the original space since the face recognition is carried out in the reduced Eigenfaces space. An experimental study was conducted to evaluate the performance of the proposed approach in terms of face recognition accuracy and spatial-temporal complexity.
Zn–Ni composite coatings were obtained by electrochemical co-deposition of TiO2 nano-particles (mean diameter 21 nm). Zn–Ni alloy coating was also produced under the same experimental conditions for comparison. The surface morphology, crystallographic structure, and the grain size of the deposits were investigated, along with the percentage of the embedded nano-particles in Zn–Ni matrix, as a function of concentration of TiO2 nano-particles in the bath. As the titania incorporation percentage is increased, a grain refinement in the nanometer region was revealed followed enhanced microhardness values and an improvement of the content of the nickel in the alloy. Annealing of all coatings at 200 °C revealed the crystallization of the matrix accompanied by a decrease of microhardness followed by stability for 24 h. The corrosion behavior of Zn–Ni/nano-TiO2 composite coatings with various amount of particle content was mainly studied by electrochemical impedance spectroscopy in 3 % NaCl. It was seen that Zn–Ni/nano-TiO2 composite coatings exhibited higher corrosion resistances comparing to Zn–Ni alloy coating and corrosion protection improved with increasing nano-TiO2 in coatings. 相似文献
In order to prepare thermally stable isosorbide-derived thermoplastic polyurethane, the synthesis of two new chiral exo–exo configured diols, prepared from isosorbide, and two types of diphenols (bisphenol A and thiodiphenol) was described. The synthesis conditions were optimized under conventional heating and microwave irradiations. To prove their suitability in polymerization, these monomers were successfully polymerized using 4,4′-diphenylmethane diisocyanate (MDI) and hexamethylene diisocyanate (HDI). Both monomers and polymers have been studied by NMR, FT-IR, TGA, DSC; intrinsic viscosity of polymers has also been determined. The results showed the effectiveness of the synthetic strategy proposed; moreover, a dramatic reduction of the reaction time and an important improvement of the monomers yield using microwave irradiation have been demonstrated. The monomers, as well as the polymers, showed excellent thermal stability both in air and nitrogen. It was also shown that the introduction of sulphur in the polyurethane backbone was effective in delaying the onset of degradation as well as the degradation rate. 相似文献
The effects of the contents of lipids, pigments, α-tocopherol and phenols were studied in relation to the antioxidant capacity
of five virgin olive oils obtained from five olive cultivars planted in Tunisia (Arbequina, Koroneiki, Leccino, Oueslati and
Chemchali). The antioxidant capacities were evaluated by two different radical scavenging activities: radical scavenging activity
by the DPPH assay (RSA-DPPH) and total antioxidant status by the ABTS test (TAA-ABTS). The highest contents of antioxidant
compounds (75.96, 10.34, 6.32, 15.39 and 241.52 mg kg−1 for oleic acid, O/L ratio, carotenes, chlorophylls and total phenols, respectively) were found for the Koroneiki cultivar
except for α-tocopherol and o-diphenols, which had the highest contents (369 and 160.7 mg kg−1, respectively) in the Leccino and Chemchali cultivars (cvs). Furthermore, the highest antioxidant capacity in virgin olive
oil was observed in the Koroneiki cultivar (0.24 mmol TE kg−1) followed by the Chemchali and Leccino cvs (0.22 and 0.13 mmol TE kg−1) for the TAA-ABTS test. However, the RSA-DPPH activity was higher for the Chemchali cultivar (19.9%) than for the Koroneiki
and Leccino cvs (18.4 and 13.5%, respectively). Correlation between these capacities and the oil composition revealed that
they were mainly influenced by the carotene content, followed by chlorophyll and phenolic contents where the ABTS test was
more pronounced. Then, the antioxidant capacity of the virgin olive oils was correlated with polar components and the lipid
profile which are important for its shelf life. 相似文献