Group items tagged

We are professional Electric power fittings supplier.we can suuply Electric power fittings to you.welcome to contact us.

we are Protective fittings supplier china ,if you need our products,you can contact us.Welcome to contact us.

Sound speed distribution, represented by a sound speed profile (SSP), is of great significance because the nonuniform distribution of sound speed will cause signal propagation path bending with Snell effect, which brings difficulties in precise underwater localization such as emergency rescue. Compared with conventional SSP measurement methods via the conductivity-temperature-depth (CTD) or sound-velocity profiler (SVP), SSP inversion methods leveraging measured sound field information have better real-time performance, such as matched field process (MFP), compressed sensing (CS) and artificial neural networks (ANN). Due to the difficulty in measuring empirical SSP data, these methods face with over-fitting problem in few-shot learning that decreases the inversion accuracy. To rapidly obtain accurate SSP, we propose a task-driven meta-deep-learning (TDML) framework for spatio-temporal SSP inversion. The common features of SSPs are learned through multiple base learners to accelerate the convergence of the model on new tasks, and the model's sensitivity to the change of sound field data is enhanced via meta training, so as to weaken the over-fitting effect and improve the inversion accuracy. Experiment results show that fast and accurate SSP inversion can be achieved by the proposed TDML method.

Thousands of ships fitted with 'cheat devices' to divert poisonous pollution into sea.

looking for buy agriculture irrigation pipe and drip irrigation pipe and fittings?we can supply our product with good price and quality to you.

We strictly follow the ISO9001 standard to build the "Boersen fitting'" brand,and have provided the high quality products for communication、power transmission、electrified railway construction.We will provide our best service for customers,the customer satisfaction is our pursuit,we welcome friends from all over the world to come to visit our factory.

The financial services of no credit check payday loans is only fit for the employed folk, who do not have to get hold of their low credit inspect by the finances provider via online. These financial services are accessible on online and are easiest way to get.

Despite the availability of satellite navigation systems, and ships that are awash with electronics, maritime buoyage still matters, particularly in pilotage waters where visual aids provide the best possible way of marking a channel or identifying obstructions. These days, buoys can be "intelligent" in that they have radar reflectors to help them show up on ship radars, possibly fitted with electronic beacons that show up on electronic charts and even made individually identifiable through their own Automated Identification System signatures. Buoys still remain very useful indeed.

Many marine megafauna taxa are tied to the sea surface for breathing which makes them vulnerable to vessel collisions. Sea turtles have developed efficient mechanisms to reduce surface time for breathing to a few seconds, but they can extend their surface periods to rest or to rewarm after diving into deep and colder waters. However, knowledge of collision occurrences is limited to data of turtles stranded along the coastline worldwide, whereas events occurring offshore go likely underestimated due to the sinking of carcasses. Here we performed a spatially explicit assessment to identify, for the first time, oceanic areas of higher exposure for sea turtles from maritime traffic in the Tyrrhenian Sea, Western Mediterranean. Satellite-tracking data were used to estimate utilization distributions of loggerhead turtles using Brownian bridge kernel density estimation. Maritime traffic density maps based on Automatic Identification System (AIS) data were extracted from open-access data layers, provided by the European Maritime Safety Agency, summarized, and used for the exposure analysis. Turtle occurrences were also investigated in response to vessel densities and seasonal patterns by fitting a generalized additive model to the data. Our results demonstrated that loggerhead turtles are potentially exposed to maritime traffic across the entire basin, especially in the easternmost part. The exposure varies among spring/summer and autumn/winter months. Highest turtle occurrences were found in regions primarily subjected to cargo, tanker, and passenger transportation. This study represents the first-ever effort to characterize the exposure of oceanic loggerhead turtles to maritime traffic and highlights oceanic areas of higher exposure where research and conservation efforts should be directed to understand the effective impact of this stressor on the species.