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211.
JIANG Ren-jie QI Fei-hu XU Li WU Guo-rong ZHU Kai-hua 《浙江大学学报(A卷英文版)》2007,8(4):568-574
This paper proposes a learning-based method for text detection and text segmentation in natural scene images. First, the input image is decomposed into multiple connected-components (CCs) by Niblack clustering algorithm. Then all the CCs including text CCs and non-text CCs are verified on their text features by a 2-stage classification module, where most non-text CCs are discarded by an attentional cascade classifier and remaining CCs are further verified by an SVM. All the accepted CCs are output to result in text only binary image. Experiments with many images in different scenes showed satisfactory performance of our proposed method. 相似文献
212.
INTRODUCTION There is increased need in recent years for strengthening or rehabilitation of existing reinforced concrete structures adversely affected by overloading, construction material deterioration, seismic loads, structural deformation, etc. An effective method for increasing the shear capacity of reinforced concrete columns is the use of externally bonded carbon fiber reinforced plastic (CFRP) systems (ACI, 2002). FRP systems were first applied to reinforced concrete col-umns i… 相似文献
213.
K. R. Shivanna 《Resonance》2016,21(11):1007-1018
After the pollen grain reaches the stigma through outsourced agents (pollinators), the next step before fertilization is to select the right type of pollen. Similar to a marriage in human beings, fiowering plants also have evolved elaborate screening process to select the right pollen grains and to reject the wrong ones. Even after initial screening for the right pollen, the pistil imposes a tough competition amongst them, comparable to a swayamvara of Indian mythology, to select the best available pollen. Flowering plants have evolved into a matriarchal society. The selection of the male partner is totally the prerogative of the mother (pistil); the boy (pollen grain) and the girl (ovule) has no say in this selection. 相似文献
214.
Sovichea Lay Hai-ning Yu Bao-xiang Hu Sheng-rong Shen 《Journal of Zhejiang University. Science. B》2016,17(6):465-475
A pre-treatment methodology for clenbuterol hydrochloride (CLEN) isolation and enrichment in a complex matrix environment was developed through exploiting molecularly imprinted polymers (MIPs). CLEN-imprinted polymers were synthesized by the combined use of ally-β-cyclodextrin (ally-β-CD) and methacrylic acid (MAA), allyl-β-CD and acrylonitrile (AN), and allyl-β-CD and methyl methacrylate (MMA) as the binary functional monomers. MAA-linked allyl-β-CD MIPs (M-MAA) were characterized by Fourier transform-infrared (FT-IR) spectroscopy and a scanning electron microscope (SEM). Based upon the results, M-MAA polymers generally proved to be an excellent selective extraction compared to its references: AN-linked allyl-β-CD MIPs (M-AN) and MMA-linked allyl-β-CD MIPs (M-MMA). M-MAA polymers were eventually chosen to run through a molecularly imprinted solid-phase extraction (MISPE) micro-column to enrich CLEN residues spiked in pig livers. A high recovery was achieved, ranging from 91.03% to 96.76% with relative standard deviation (RSD) ≤4.45%. 相似文献
215.
Hui-ping Lin Jun Lin Juan Li Jing-hong Xu Christian Mehl 《Journal of Zhejiang University. Science. B》2016,17(11):864-873
Resin-dentin bond degradation is a major cause of restoration failures. The major aim of the current study was to evaluate the impact of a remineralization medium on collagen matrices of hybrid layers of three different adhesive resins using nanotechnology methods. Coronal dentin surfaces were prepared from freshly extracted premolars and bonded to composite resin using three adhesive resins (FluoroBond II, Xeno-III-Bond, and iBond). From each tooth, two central slabs were selected for the study. The slabs used as controls were immersed in a simulated body fluid (SBF). The experimental slabs were immersed in a Portland cement-based remineralization medium that contained two biomimetic analogs (biomineralization medium (BRM)). Eight slabs per group were retrieved after 1, 2, 3, and 4 months, respectively and immersed in Rhodamine B for 24 h. Confocal laser scanning microscopy was used to evaluate the permeability of hybrid layers to Rhodamine B. Data were analyzed by analysis of variance (ANOVA) and Tukey’s honest significant difference (HSD) tests. After four months, all BRM specimens exhibited a significantly smaller fluorescent area than SBF specimens, indicating a remineralization of the hybrid layer (P≤0.05). A clinically applicable biomimetic remineralization delivery system could potentially slow down bond degradation. 相似文献
216.
Rachel J. Bar Stephanie E. Cassin Michelle M. Dionne 《European Journal of Sport Science》2016,16(3):325-335
A substantial amount of evidence suggests that collegiate and elite athletes involved in weight-sensitive sports are at greater risk of developing eating disorders (EDs) than the general population. With the limited effectiveness of treatment for EDs, prevention of EDs has been broadly considered in the literature. The present paper reviewed the existing literature on ED prevention programmes for athletes in order to determine the current status of prevention programmes and recommend future directions. The available literature suggests that selective, primary interventions with multiple targets and an interactive multimodal approach appear most effective. Current challenges in the field, including lack of longitudinal research, hesitation by the sport community to be involved in ED research and poor cross-field communication and collaboration, are also explored. The lack of dissemination of evidence-based prevention programmes and the simultaneous promotion of prevention programmes that have not yet been empirically examined are also discussed. Based on these observations future directions are recommended. 相似文献
217.
218.
An excellent airfoil with a high lift-to-drag ratio may decrease oil consumption and enhance the voyage. Based on NACA 0012, an improved airfoil is explored in this paper. The class/shape function transformation has been proved to be a good method for airfoil parameterization, and in this paper it is modified to improve imitation accuracy. The computational fluid dynamics method is applied to obtain numerically the aerodynamic parameters of the parameterized airfoil, and the result is proved credible by comparison with available experimental data in the open literature. A polynomial-based response surface model and the uniform Latin hypercube sampling method are employed to decrease computational cost. Finally, the nonlinear programming by quadratic Lagrangian method is utilized to modify the multi-island genetic algorithm, which has an improved optimization effect than the method used on its own. The obtained result shows that the modified class/shape function transformation method produces a better imitation of an airfoil in the nose and tail regions than the original method, and that it will satisfy the tolerance zone of the model in a wind tunnel. The response surface model based on the uniform Latin hypercube sampling method gives an accurate prediction of the lift-to-drag ratio with changes in the design variables. The numerical result of the flow around the airfoil shows reasonable agreement with the experimental data graphically and quantitatively. Ultimately, an airfoil with better capacity than the original one is acquired using the multi-island genetic algorithm based nonlinear programming by quadratic Lagrangian optimization method. The pressure contours and lift-to-drag ratio along with the attack angle have been compared with those of the original airfoil, and the results demonstrate the strength of the optimized airfoil. The process for exploring an improved airfoil through parameterization to optimization is worth referencing in future work. 相似文献
219.
Shujie Liu Xianxuan Xu James H. Stronge 《Educational Assessment, Evaluation and Accountability》2016,28(2):161-177
Teacher performance evaluation currently is receiving unprecedented attention from policy makers, scholars, and practitioners worldwide. This study is one of the few studies of teacher perceptions regarding teacher performance measures that focus on China. We employed a quantitative dominant mixed research design to investigate Chinese teachers’ preferences for teacher performance measures and the possible reasons for their preferences. Considering the quantitative results, the surveyed Chinese teachers identified fulfillment of additional roles, collaboration with faculty and staff, and students’ test scores as the most important measures for performance evaluation. Qualitatively, the most important measures that the surveyed teachers reported were the teacher’s morality, workload, and students’ test scores. 相似文献
220.
Jordan J. Smith Philip J. Morgan Ronald C. Plotnikoff David F. Stodden David R. Lubans 《Journal of sports sciences》2016,34(8):772-779
The purpose of this study was to examine the mediating effect of resistance training skill competency on percentage of body fat, muscular fitness and physical activity among a sample of adolescent boys participating in a school-based obesity prevention intervention. Participants were 361 adolescent boys taking part in the Active Teen Leaders Avoiding Screen-time (ATLAS) cluster randomised controlled trial: a school-based program targeting the health behaviours of economically disadvantaged adolescent males considered “at-risk” of obesity. Body fat percentage (bioelectrical impedance), muscular fitness (hand grip dynamometry and push-ups), physical activity (accelerometry) and resistance training skill competency were assessed at baseline and post-intervention (i.e., 8 months). Three separate multi-level mediation models were analysed to investigate the potential mediating effects of resistance training skill competency on each of the study outcomes using a product-of-coefficients test. Analyses followed the intention-to-treat principle. The intervention had a significant impact on the resistance training skill competency of the boys, and improvements in skill competency significantly mediated the effect of the intervention on percentage of body fat and the combined muscular fitness score. No significant mediated effects were found for physical activity. Improving resistance training skill competency may be an effective strategy for achieving improvements in body composition and muscular fitness in adolescent boys. 相似文献