An algorithm for power transmission line fault detection based on improved YOLOv4 model.

In response to the escalating demand for real-time and accurate fault detection in power transmission lines, this paper undertook an optimization of the existing YOLOv4 network. This involved the substitution of the main feature extraction network within the original YOLOv4 model with a lighter EfficientNet network. Additionally, the inclusion of Grouped Convolution modules in the feature pyramid structure replaced conventional convolution operations. The resulting model not only reduced model parameters but also effectively ensured detection accuracy. Moreover, in enhancing the model's reliability, data augmentation techniques were employed to bolster the robustness of the power transmission line fault detection algorithm. This optimization further utilized the DIoU loss function to stabilize target box regression. Comparative experiments demonstrated the improved YOLOv4 model's superior performance in terms of loss function optimization while significantly enhancing detection speed under equivalent configurations. The parameter capacity was reduced by 81%, totaling merely 43.65 million, while the frame rate surged by 85% to achieve 24 frames per second. These experimental findings validate the effectiveness of the algorithm.

[Influence of immunization dose schemes on the immune response to anti-tetrodotoxin vaccine].

OBJECTIVE: To study the relationship between the immune response of anti-tetrodotoxin vaccine, including its dose-response, and to select optimal immunization dose so as to enhance antitoxic effect of the anti-tetrodotoxin vaccine. METHODS: Tetrodotoxin (TTX) was coupled to Tachypleus tridentatus hemocyanin (TTH) chemically to form artificial antigen (TTX-TTH), and with which Balb/c mice were immunized. Influence of different immunization doses [100 microg as the higher (H) and 25 microg as the lower (L) dose group] on the protective effects of TTX vaccine was compared. The quality of antisera and effects of vaccine in anti-TTX poisoning were observed. RESULTS: The sera antibody quality increased more quickly in group L than that in group H after immunization. The dose at which the half of immunized mice survived when challenged once with TTX were 16 x LD (1 LD = 13.5 microg/kg, i.p.) in group L and 11 x LD in group H. When TTX was used time and again, the half of immunized mice could tolerate as high as 40 x LD and 22 x LD of accumulated dose, and the maximum tolerable cumulated dose was 104 x LD and 90 x LD for group L and H respectively. The scheme L was better both in antibody quality and effect of protecting against TTX toxicity than that in scheme H. CONCLUSIONS: The experimental vaccine of TTX could effectively protect animal from TTX intoxication. The lower immunization dose in this study is selected as the optimal immunization scheme.

[Toxicity of tetrodotoxin towards mice and rabbits].

The toxicity of tetrodotoxin(TTX) in Kunming mice and rabbits was investigated in this study. The median lethal doses (LD50) were 10.7, 12.5, 532 micrograms/kg for intraperitoneal (i.p.), subcutaneous (s.c.) and intragastric (ig) administration of toxin respectively in mice and, it was found that the male mice was more sensitive to TTX than the female was. TTX toxic doses for both intramuscular (i.m.) and intravenous (i.v.) administration via injection in rabbits were reported first time and the minimal lethal doses(MLD) were 5.3, 3.1 micrograms/kg and wholly lethal doses(LD) were 5.8, 3.8 micrograms/kg for i.m. and i.v. injection respectively. TTX-intoxication symptoms and characteristics were described in both animal species and in different administrations of toxin. TTX was found to be about fifty times less toxic and to have more delayed death occurrence to mice via oral route than that via i.p. injection, providing, more likely, a favorable potential for the cure of actual TTX-poisoning victims.