Experimental Study of Bellows Duct Grouting Compactness with Quantitative Detection

2014 ◽  
Vol 716-717 ◽  
pp. 322-327 ◽  
Author(s):  
Feng Chu ◽  
Yuan Cao ◽  
Guang Zhi Qi ◽  
Lei Gao

In order to quantitatively detect the compactness of bellows duct grouting, by studying time-histories relation curve forming by ultrasonic wave transmitting in different thicknesses concrete samples. We get the acoustic time rule after ultrasonic passed through different compactness bellows duct. At the same time, establishing empty hole estimation model corresponding to the concrete samples and providing theoretical basis for judging porosity and predicting the grouting quality in the bellows duct. Meanwhile, dividing the bellows duct into five degrees complete compactness, 3/4 compactness, 1/2 compactness, 1/4 compactness, empty by setting up defects in the bellows duct, and then embedding them in concrete slab to do ultrasonic detection. The detection result shows that ultrasonic detection method can effectively quantitive estimate the grouting quality of prestressed bellows duct with establishing empty hole estimation model.

2014 ◽  
Vol 711 ◽  
pp. 461-468 ◽  
Author(s):  
Shao Lin Zhou ◽  
Feng Zhang ◽  
Yuan Cao

The ultrasonic method can be used for testing and analyzing the pore size of concrete. By studying the spectrum curves which is formed by ultrasonic transmitting at different thickness concrete panels can we get different time regular patterns of head waves formed by ultrasonic going through homogeneous concrete, compact grouting pore, grouting incompact pore, not grouting pore. All these provide a basis for predicting prestressed bellows pore grouting quality and judging whether there is interspace in pore. By artificially setting defects in bellows pore, for example, filling the pore to completely empty, 1/4 compact, 1/2 compact, 3/4 compact, fully compact and then embedding them in a concrete slab for ultrasonic testing. Test results show that the ultrasonic method can effectively evaluate the grouting quality of prestressed bellows pore.


2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Tong Wang

The compaction quality of the subgrade is directly related to the service life of the road. Effective control of the subgrade construction process is the key to ensuring the compaction quality of the subgrade. Therefore, real-time, comprehensive, rapid and accurate prediction of construction compaction quality through informatization detection method is an important guarantee for speeding up construction progress and ensuring subgrade compaction quality. Based on the function of the system, this paper puts forward the principle of system development and the development mode used in system development, and displays the development system in real-time to achieve the whole process control of subgrade construction quality.


2013 ◽  
Vol 61 (1) ◽  
pp. 111-121 ◽  
Author(s):  
T. Jankowiak ◽  
T. Łodygowski

Abstract The paper considers the failure study of concrete structures loaded by the pressure wave due to detonation of an explosive material. In the paper two numerical methods are used and their efficiency and accuracy are compared. There are the Smoothed Particle Hydrodynamics (SPH) and the Finite Element Method (FEM). The numerical examples take into account the dynamic behaviour of concrete slab or a structure composed of two concrete slabs subjected to the blast impact coming from one side. The influence of reinforcement in the slab (1, 2 or 3 layers) is also presented and compared with a pure concrete one. The influence of mesh density for FEM and the influence of important parameters in SPH like a smoothing length or a particle distance on the quality of the results are discussed in the paper


Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 567
Author(s):  
Donghun Yang ◽  
Kien Mai Mai Ngoc ◽  
Iksoo Shin ◽  
Kyong-Ha Lee ◽  
Myunggwon Hwang

To design an efficient deep learning model that can be used in the real-world, it is important to detect out-of-distribution (OOD) data well. Various studies have been conducted to solve the OOD problem. The current state-of-the-art approach uses a confidence score based on the Mahalanobis distance in a feature space. Although it outperformed the previous approaches, the results were sensitive to the quality of the trained model and the dataset complexity. Herein, we propose a novel OOD detection method that can train more efficient feature space for OOD detection. The proposed method uses an ensemble of the features trained using the softmax-based classifier and the network based on distance metric learning (DML). Through the complementary interaction of these two networks, the trained feature space has a more clumped distribution and can fit well on the Gaussian distribution by class. Therefore, OOD data can be efficiently detected by setting a threshold in the trained feature space. To evaluate the proposed method, we applied our method to various combinations of image datasets. The results show that the overall performance of the proposed approach is superior to those of other methods, including the state-of-the-art approach, on any combination of datasets.


Author(s):  
Mingliang Xu ◽  
Qingfeng Li ◽  
Jianwei Niu ◽  
Hao Su ◽  
Xiting Liu ◽  
...  

Quick response (QR) codes are usually scanned in different environments, so they must be robust to variations in illumination, scale, coverage, and camera angles. Aesthetic QR codes improve the visual quality, but subtle changes in their appearance may cause scanning failure. In this article, a new method to generate scanning-robust aesthetic QR codes is proposed, which is based on a module-based scanning probability estimation model that can effectively balance the tradeoff between visual quality and scanning robustness. Our method locally adjusts the luminance of each module by estimating the probability of successful sampling. The approach adopts the hierarchical, coarse-to-fine strategy to enhance the visual quality of aesthetic QR codes, which sequentially generate the following three codes: a binary aesthetic QR code, a grayscale aesthetic QR code, and the final color aesthetic QR code. Our approach also can be used to create QR codes with different visual styles by adjusting some initialization parameters. User surveys and decoding experiments were adopted for evaluating our method compared with state-of-the-art algorithms, which indicates that the proposed approach has excellent performance in terms of both visual quality and scanning robustness.


2013 ◽  
Vol 380-384 ◽  
pp. 1725-1728
Author(s):  
Yang Hu ◽  
Huai Yu Kang

In this paper, we Research on Propagation Numerical Simulation and damage effect of Blast Shock Waves in Subway Station by using LS-DYNA dynamic finite element calculation program , the results reproduce the formation process of the explosive flow field, and analysis the shock wave waveform, attenuation and walking pattern, provides the theoretical basis for further experimental study.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jingyao Cai ◽  
Min Hu ◽  
Zhiyang Chen ◽  
Zeng Ling

AbstractLiver fibrosis occurs in response to any etiology of chronic liver injury. Lack of appropriate clinical intervention will lead to liver cirrhosis or hepatocellular carcinoma (HCC), seriously affecting the quality of life of patients, but the current clinical treatments of liver fibrosis have not been developed yet. Recent studies have shown that hypoxia is a key factor promoting the progression of liver fibrosis. Hypoxia can cause liver fibrosis. Liver fibrosis can, in turn, profoundly further deepen the degree of hypoxia. Therefore, exploring the role of hypoxia in liver fibrosis will help to further understand the process of liver fibrosis, and provide the theoretical basis for its diagnosis and treatment, which is of great significance to avoid further deterioration of liver diseases and protect the life and health of patients. This review highlights the recent advances in cellular and molecular mechanisms of hypoxia in developments of liver fibrosis.


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