A learning-based method to detect and segment text from scene images

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.     

Shear capacity of reinforced concrete columns strengthened with CFRP sheet

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…     

Molecularly imprinted polymers as the extracted sorbents of clenbuterol ahead of liquid chromatographic determination

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%.     

In vitro remineralization of hybrid layers using biomimetic analogs

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.     

A study of airfoil parameterization,modeling, and optimization based on the computational fluid dynamics method

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.     

Chinese middle school teachers’ preferences regarding performance evaluation measures

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.     

Biomechanical characteristics of adults walking forward and backward in water at different stride frequencies

The aim of this study was to examine spatiotemporal characteristics and joint angles during forward and backward walking in water at low and high stride frequency. Eight healthy adults (22.1 ± 1.1 years) walked forward and backward underwater at low (50 pulses) and high frequency (80 pulses) at the xiphoid process level with arms crossed at the chest. The main differences observed were that the participants presented a greater speed (0.58 vs. 0.85 m/s) and more asymmetry of the step length (1.24 vs. 1.48) at high frequency whilst the stride and step length (0.84 vs. 0.7 m and 0.43 vs. 0.35 m, respectively) were lower compared to low frequency (P < 0.05). Support phase duration was higher at forward walking than backward walking (61.2 vs. 59.0%). At initial contact, we showed that during forward walking, the ankle and hip presented more flexion than during backward walking (ankle: 84.0 vs. 91.8º and hip: 22.8 vs. 8.0º; P < 0.001). At final stance, the knee and hip were more flexed at low frequency than at high frequency (knee: 150.0 vs. 157.0º and hip: ?12.2 vs. –14.5º; P < 0.001). The knee angle showed more flexion at forward walking (134.0º) than backward walking (173.1º) (P < 0.001). In conclusion, these results show how forward and backward walking in water at different frequencies differ and contribute to a better understanding of this activity in training and rehabilitation.     

Bedingungen der Bindungswirkung inkrementeller Normen in Fußballvereinen

Sports clubs depend on the pooling of resources by their members. The supportive distribution of the resources within a club is facilitated in particular by the effectiveness of incremental standards. A basic prerequisite for a fair distribution of resources is a minimum of community spirit among the members. Based on a nationwide survey of football clubs and an ordinal logistic regression model, factors were determined that reflect the extent of the community spirit within a club. The opening up of the club by payment to players and perceived problems with acquiring and binding of volunteers are associated with a reduction of community spirit. In contrast, the perception that the club activities can be continued in the long term shows a positive correlation to a highly developed community spirit.     

A channel distortion model for video over lossy packet networks

Error-resilient video communication over lossy packet networks is often designed and operated based on models for the effect of losses on the reconstructed video quality. This paper analyzes the channel distortion for video over lossy packet networks and proposes a new model that, compared to previous models, more accurately estimates the expected mean-squared error distortion for different packet loss patterns by accounting for inter-frame error propagation and the correlation between error frames. The accuracy of the proposed model is validated with JVT/H.264 encoded standard test sequences and previous frame concealment, where the proposed model provides an obvious accuracy gain over previous models.