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IntroductionStatistical methods such as empirical orthogonal functions (EOFs) are often used to model the sound speed profile (SSP). However, their statistical nature often leads to the sample dependence and physical fuzziness.MethodThis study proposes a technique for modeling the SSP from the perspective of ocean dynamics. It employs the ocean normal mode, which is the mode of fluid particles motion, to deduce perturbations in the SSP, which is called the ocean mode basis (OMB).ResultThe results of SSP reconstruction of in-situ samples showed that a few leading orders of the OMB can provide a compact representation of the SSP. Oscillations of the contours and gradient of the sound speed in thermocline were analyzed by using the first two orders of the projection coefficients of the relationship between the OMB and the baroclinic mode. As a physical model, this technique can also be used to characterize the dynamics of internal solitary waves. Furthermore, the OMB derived from archival date was used for SSP inversion. The results showed that the OMB can reconstruct SSP of a reasonable resolution without requiring in-situ samples.DiscussionCompared with statistical models, the OMB can better explain the ocean dynamics underlying variations in the SSP while requiring fewer samples.

Optical hydrogen sensors offer high sensitivity, high accuracy, and non-invasive sensing capabilities, making them promising devices in various fields, including the construction of hydrogen fuel cells, storage and transportation, and aerospace. However, to achieve better sensitivity and faster reaction times, such sensors are often constructed as nano-arrays or nano-gratings, leading to increased manufacturing costs and complexity. In this study, we propose and demonstrate a highly sensitive hydrogen sensor based on a multilayer structure. The proposed structure consists of a Pd metal film and a photonic crystal with a defect layer, in which the photonic crystal is designed by an alternating arrangement of Ta2O5 and SiO2, and the material comprising the defect layer is SiO2. With a sensitivity of up to 16,020 at 670 nm, the proposed sensor relies on the coupling of Tamm plasmon polaritons and defect modes. The electric field distribution inside the structure is also provided in order to reveal its physical mechanism. Furthermore, we investigate the effects of the thickness of the defect layer and the angle of incident light on the sensor’s performance. The study results show that the sensor has good fault tolerance in either scenario. The findings of this study open up new possibilities for hydrogen sensor applications.

In the highway intelligent monitoring system, it is difficult to find the target vehicle through millions of pictures because of the presence of fake-licensed vehicles. In order to solve this problem, a vehicle comparison and re-identification (Re-ID) system is built in this paper. By introducing Circle loss and Generalized-Mean(GeM) pooling, vehicle feature extraction and storage, vehicle comparison and vehicle search can be realized. Experimental results show that the proposed algorithm reaches 95.79% of the mean Average Precision (mAP) on the vehicle search task, which meets the requirements of practical applications.

Background: Pain is the most common cancer-related symptom, but it is often undertreated. Telemedicine is widely used in cancer treatment, but its effectiveness is uncertain. Objective: We aimed to evaluate the impact of telemedicine intervention on pain in patients with cancer. Design: Methodological quality and risk-of-bias evaluation were conducted, and the sources of heterogeneity were explored through subgroup analysis and sensitivity analysis. Data Sources and Methods: PubMed, Embase, Web of Science, Cochrane Library, and clinical trial databases were searched up to 16 August 2022. Randomized controlled trials of the impact of telemedicine intervention regarding pain in patients with cancer were included, and the results related to pain were extracted. Results: Twenty-one randomized controlled trials were selected from 1810 articles. A total of 1454 patients received telemedicine interventions, and 2213 received conventional medical services. Telemedical intervention had a positive effect on improving pain intensity [standard mean deviation (SMD) = −0.28, 95% confidence interval (CI): −0.49 to −0.06, p = 0.01] and pain interference (SMD = −0.41, 95% CI: −0.54 to −0.28, p