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Enhanced Fish Detection in Underwater Video Using Wavelet-Based Color Correction and Machine Learning
Published in Monika Mangla, Subhash K. Shinde, Vaishali Mehta, Nonita Sharma, Sachi Nandan Mohanty, Handbook of Research on Machine Learning, 2022
Jitendra P. Sonawane, Mukesh D. Patil, Gajanan K. Birajdar
Imaging in an underwater environment is generally affected by poor visibility, low contrast, and color degradation because of light attenuation in water. The attenuation of light is caused by absorption and scattering. In water, attenuation of light impacts the general execution of the framework for the underwater environment. As the light entering in medium gets collided with molecules/particles present in the water, the incident light gets reflected, refracted, or scattered depending on the wavelength of the incident wave. Forward scattering results in blurring of signal, whereas backward scattering limits the contrast of the images, which then consolidates the impacts on the quality of video received at the processing end [1].
The self-healing properties and mechanism of the cracked fly ash-based engineered geopolymer composites (FA-EGC): effects of water and temperature
Published in Journal of Sustainable Cement-Based Materials, 2023
Xiaolu Guo, Shuting Yuan, Xinhao Liu
According to our previous studies [47], the effect of cracking ages (i.e. 3 days, 7 days, 14 days, and 28 days) on the self–healing of FA-EGC was evaluated by crack characteristics, tensile properties, and water absorption, which showed that there was an optimum self–healing effect of FA-EGC samples when cracking age is 7 days. Therefore, after pre-tensioning to the strain of 2% at the age of 7 day (Figure 2), the prepared samples with preloaded cracks were exposed into four different environments and self-healed for different ages to simulate real service environments: (1) Air: the samples were placed in the laboratory directly to simulate the indoor environment; (2) Wet-dry cycles (w/d): in one cycle, the samples were submerging in water for 12 h and then drying in air for 12 h to simulate the outdoor environment with rain and sunshine alternating; (3) 20 °C water: the samples were submerging in water at room temperature (about 20 °C) to simulate the underwater environment in subtropical regions such as Shanghai, China, etc.; (4) 40 °C water: the samples were submerging in 40 °C water to simulate the underwater environment in tropical regions such as Hainan, China, etc. (Figure 2). Moreover, three samples were cured in each curing condition.
Finite-time flocking and collision avoidance for second-order multi-agent systems
Published in International Journal of Systems Science, 2020
Hongliang Liu, Xiao Wang, Xiang Li, Yicheng Liu
It is well known that collision avoiding is a very important issue in our real life. For example, each bird in a group adjusts its state to guarantee collision avoiding with its neighbours when they fly in the sky. Hence, in any situation where the described phenomenon involves flocking of multi-agents, one should naturally consider the collision avoidance. In fact, collision avoidance control has been widely applied in engineering field. Take autonomous underwater vehicles (short for AUVs) for an example, in order to complete the special tasks, such as oceanographic surveys, deep sea inspections or ocean exploration, we not only require AUVs to form a desired formation in a finite-time but also require them not to collide with each other in the complicated underwater environment. Therefore, the issue of collision avoiding plays a key role on the practical applications. Nevertheless, according to the authors' observation, there are few results on collision avoiding in the multi-agent systems (Ahn, Choi, Ha, & Lee, 2012; Carrillo, Choi, Mucha, & Peszek, 2017; Cucker & Dong, 2010, 2011) and there are still many challenges remained. To the best of our knowledge, there is no result dealing with collision avoiding in finite time flocking for the second-order multi-agent system in the literature so far.
Efficiency of solar PV panel by the application of coconut fibres saturated by earthen clay pot water
Published in Environmental Technology, 2021
R. Rajasekar, P. Prasannaa, R. Ramkumar
Sheeba et al. [7], to improve the efficiency of PV cells, had experimentally carried out a study through the operation of temperature reduction. The panel temperature was reduced by placing the panel in the underwater environment at various depths and flow rates of water and achieved a maximum efficiency of 21.6%. According to the Coir Board [8], the coir pith constitute 50%–70% of the husk. It is a very high and compressible material, which holds water by six to eight times than its weight. It also acts as an excellent moisture retentive material even after drying.