ia-PNCC: Noise Processing Method for Underwater Target Recognition Convolutional Neural Network

Underwater target recognition is a key technology for underwater acoustic countermeasure.How to classify and recognize underwater targets according to the noise information of underwater targets has been a hot topic in the field of underwater acoustic signals.In this paper,the deep learning model is applied to underwater target recognition.Improved anti-noise Power-Normalized Cepstral Coefficients(ia-PNCC)is proposed,based on PNCC applied to underwater noises.Multitaper and normalized Gammatone filter banks are applied to improve the anti-noise capacity.The method is combined with a convolutional neural network in order to recognize the underwater target.Experiment results show that the acoustic feature presented by ia-PNCC has lower noise and are wellsuited to underwater target recognition using a convolutional neural network.Compared with the combination of convolutional neural network with single acoustic feature,such as MFCC(Mel-scale Frequency Cepstral Coefficients)or LPCC(Linear Prediction Cepstral Coefficients),the combination of the ia-PNCC with a convolutional neural network offers better accuracy for underwater target recognition.

PMS-Sorting:A New Sorting Algorithm Based on Similarity

Borda sorting algorithm is a kind of improvement algorithm based on weighted position sorting algorithm,it is mainly suitable for the high duplication of search results,for the independent search results,the effect is not very good and the computing method of relative score in Borda sorting algorithm is according to the rule of the linear regressive,but position relationship cannot fully represent the correlation changes.aimed at this drawback,the new sorting algorithm is proposed in this paper,named PMS-Sorting algorithm,firstly the position score of the returned results is standardized processing,and the similarity retrieval word string with the query results is combined into the algorithm,the similarity calculation method is also improved,through the experiment,the improved algorithm is superior to traditional sorting algorithm.

Effect of the exposure to suspended solids on the enzymatic activity in the bivalve Sinonovacula constricta

Aquatic animals are susceptible to sudden changes of their living environment but they adopt strategies to cope with adverse environmental challenges.Contamination by suspended solids,often associated with a dramatic change in the concentrations of important water-quality variables is a frequent occurrence in China's coastal waters and estuaries.Here we studied the impact of suspended solids on the activities of the antioxidant enzymes superoxide dismutase(SOD)and catalase(CAT),as well as adenosine triphosphates(including Na^(+)K^(+)-ATPase,Mg^(++)-ATPase,Ca^(++)-ATPase)and H^(+)K^(+)-ATPase in the gills and visceral mass tissues of the molluscan bivalve Sinonovacula constricta exposed(4,8,12,16,20,and 24 days)to various concentrations of suspended solids.Our results showed that the antioxidant enzymes cooperated closely to effectively scavenge superoxide anion free radicals and H2O2(which can ultimately inhibit gill activity)through the modification of SOD and/or CAT enzymatic activities.ATPases activity(considered to be a sensitive indicator of toxicity)could play an effective role in the maintenance of functional integrity of the plasma membranes as well as some other intracellular functions.After the exposure,a decrease in the Nat K^(+)-ATPase,Mg^(++)-ATPase,and Ca^(++)-ATPase activity of the gills was observed suggesting that they were inhibited by the treatments.These results also indicated that,from day 4 to day 16,exposure to high concentrations of suspended solids had an inhibitory effect on the activity of H^(+)-K^(+)-ATPase in the visceral mass of S.constricta.However,after a period of adaptation the H^(+)-K^(+)-ATPase activity was restored to original levels.Our results suggest that long-term exposure to high levels of suspended solids disturb osmoregulation,gastric acid secretion and digestion,cause oxidative damage,as a consequence of antioxidant enzymes inactivation which eventually damages the gills,affect the food intake and transformation,ultimately resulting in systems failure and eventually death.