Study on stud performance of steel UHPC composite structure based on temperature

The stress and deformation of the specimen under static load and temperature load coupling are deduced by simulation. With the help of finite element software ABAQUS, the user subroutines DFLUX and FILM are called to introduce the temperature field, so as to realize the analysis and Research on the stress, displacement, PEEQ, arrangement and load slip curve of the stud under different action conditions. The results show that based on the existence of temperature stress, the service performance of studs under coupling action is significantly lower than that under static action alone, and the proportion of shear performance of studs in different rows is different. Through the research and analysis of the above phenomena, it can provide reference value for the research of temperature on the performance of studs in composite bridge deck and prolong the service life of bridge deck.

Action Recognition Using a Spatial-Temporal Network for Wild Felines

Behavior analysis of wild felines has significance for the protection of a grassland ecological environment. Compared with human action recognition, fewer researchers have focused on feline behavior analysis. This paper proposes a novel two-stream architecture that incorporates spatial and temporal networks for wild feline action recognition. The spatial portion outlines the object region extracted by Mask region-based convolutional neural network (R-CNN) and builds a Tiny Visual Geometry Group (VGG) network for static action recognition. Compared with VGG16, the Tiny VGG network can reduce the number of network parameters and avoid overfitting. The temporal part presents a novel skeleton-based action recognition model based on the bending angle fluctuation amplitude of the knee joints in a video clip. Due to its temporal features, the model can effectively distinguish between different upright actions, such as standing, ambling, and galloping, particularly when the felines are occluded by objects such as plants, fallen trees, and so on. The experimental results showed that the proposed two-stream network model can effectively outline the wild feline targets in captured images and can significantly improve the performance of wild feline action recognition due to its spatial and temporal features.

Analysis of the Spatial Behaviour of Masonry Bridges Via Hierarchical FEM Modelling: the Devil’s Bridge

The contribution of the fill to the global behavior of masonry vaulted bridges may be primarily significant. Nevertheless, ordinary analyses conducted on masonry bridges usually consider only the main structural vaulted elements. The paper reports some results obtained through a numerical simulation developed on a FEM model of an ancient bridge, the Devil’s bridge on Sele river at Barrizzo, in the Campania region. The study is aimed at showing how the fill may be contributing with a significant static action , changing the real carrying capacity of the bridge as regards applied loads. The study allows to highlight the spatial behavior of the single components and of the overall structure as well, in terms of stresses and deformed configurations under the self- weight and the accidental loads.

Exploiting Motion Information from Unlabeled Videos for Static Image Action Recognition

Static image action recognition, which aims to recognize action based on a single image, usually relies on expensive human labeling effort such as adequate labeled action images and large-scale labeled image dataset. In contrast, abundant unlabeled videos can be economically obtained. Therefore, several works have explored using unlabeled videos to facilitate image action recognition, which can be categorized into the following two groups: (a) enhance visual representations of action images with a designed proxy task on unlabeled videos, which falls into the scope of self-supervised learning; (b) generate auxiliary representations for action images with the generator learned from unlabeled videos. In this paper, we integrate the above two strategies in a unified framework, which consists of Visual Representation Enhancement (VRE) module and Motion Representation Augmentation (MRA) module. Specifically, the VRE module includes a proxy task which imposes pseudo motion label constraint and temporal coherence constraint on unlabeled videos, while the MRA module could predict the motion information of a static action image by exploiting unlabeled videos. We demonstrate the superiority of our framework based on four benchmark human action datasets with limited labeled data.

Structure and protective properties of epoxy-polyester powder coatings containing curing accelerator

As a result of the study, the effect of curing accelerators (heterocyclic amine and zinc-containing accelerator) on the structure, physico-mechanical and protective properties of coatings based on powder epoxy-polyester compositions was established. The introduction of accelerators into the compositions affects the depth and speed of the curing process of film formers and provides the possibility to reduce the curing temperature. It has been established that the use of heterocyclic amine accelerator is more effective than a zinc-containing catalyst. For compositions containing heterocyclic amine, a decrease in gel time and an increase in the complex of physico-mechanical and protective characteristics of the coatings are observed, which were evaluated for the resistance of the coatings to the static action of a 3 % solution of sodium chloride. It is shown that changes in the protective properties of coatings, depending on the composition, correlate with the structural parameters of the polymer film and are due to the formation of the spatial structure of the polymer with different cross-link density. The use of mixtures of the investigated curing accelerators leads to an increase in the density of the polymer spatial network. This provides high protective properties of coatings to the action of aggressive electrolytes by reducing the permeability of corrosive media into the coating material. For 5000 hours of testing there are no pockets of corrosion under a film and no significant disruption of the continuity of the coatings (bubbles, peeling, wrinkling and cracking) in comparison with the basic compositions that do not contain accelerators.

The effects of integrating goal setting and reading strategy instruction on English reading proficiency and learning motivation: A quasi-experimental study

An English as a Foreign Language (EFL) reading class was transformed by integrating goal setting with reading strategy instruction for one academic year. This intervention class was compared to a traditionally taught class to determine whether any differences in terms of motivation towards learning English and reading proficiency would be found. The goals set by the intervention class were analyzed to determine (1) whether they were met and (2) what actions were performed to reach those goals. In addition, it was further investigated whether adolescent Taiwanese students are willing to be taught English reading using an approach incorporating goal setting and reading strategy instruction. Results indicate that goal setting integrated reading strategy instruction seems to be more effective in increasing reading proficiency and learner motivation than the traditional approach as well as encouraging learner autonomy and self-efficacy. Analysis of the actions performed by the intervention group to meet goals revealed two sub-groups of learners: static action students and dynamic action students. Data analysis further indicated the actions performed by dynamic action students consisted of more diverse and concrete learning strategies whereas static action students performed mostly classroom-centered review. Pedagogical implications of the results and future research directions are discussed.