Linear and nonlinear impairments in underwater wireless optical communication (UWOC) systems caused by the limited bandwidth nonlinearity of devices severely degrade system performance. In this paper, we propose a sparse Volterra series model-based post equalizer with greedy algorithms to mitigate inter-symbol interference (ISI) UWOC system. A variable step size generalized orthogonal matching pursuit (VSgOMP) algorithm that combines (gOMP) adaptive method is proposed employed compress low...

We propose and experimentally demonstrate an underwater wireless optical communication (UWOC) system using a 520-nm laser diode (LD) 32-quadrature amplitude modulation (32-QAM) single carrier signals. To mitigate the inter-symbol interference (ISI), frequency domain equalizer combined with time-domain decision feedback noise predictor is employed at receiver. However, this structure cannot apply channel coding conjunctively. Therefore, interleaver/deinterleaver pair applied to handle...

Due to the proliferation of underwater vehicles and sensors, wireless optical communication (UWOC) is a key enabler for ocean exploration with strong reliance on short-range bandwidth-intensive communications. A stable link primary importance UWOC. compact, low-power, low-cost acquisition, pointing, tracking (APT) system proposed experimentally demonstrated realign within 0.04 s, even when UWOC transmitter receiver are in relative motion. The successfully achieves rapid auto-alignment...

To deal with the challenges posed by generational differences in China’s sustainable consumption transition, this study’s pioneers using a mixed-methods approach data mining and literature research to classify Chinese residents into four generations based on perspective. We developed conceptual model of conducted an empirical study structured interviews multi-stage random sampling approach. The results highlight significant distinct influencing mechanisms among regarding perceptions...

The transmission distance, alignment requirement and stability of underwater wireless optical communication (UWOC) systems are usually difficult to trade off. In this article, ensure that the spot at receiver end has sufficient power uniform distribution, transmitter a UWOC system is designed based on single-color light-emitting diode (LED) array with beam shaping system. lens group-based scheme not only extends but still maintains easy-alignment nature LED-based link. At receiver, diversity...

In this paper, a quasi-omnidirectional transmitter is proposed and demonstrated for underwater wireless optical communication (UWOC) using the photoluminescence of perovskite quantum dots (QDs). The transmitter, without complex driving circuits, compact reliable thanks to lens-free design. system performance tested in 50-m swimming pool with water attenuation coefficient 0.38 dB/m. maximum data rates on-off-keying (OOK) signals over 10-m 20-m transmission distances can reach 60 Mbps 40 Mbps,...

The usage of Python idioms is popular among developers in a formative study 101 idiom performance related questions on Stack Overflow, we find that often get confused about the impact and use anecdotal toy code or rely personal project experience which contradictory outcomes. There has been no large-scale, systematic empirical evidence to reconcile these debates. In paper, create large synthetic dataset with 24,126 pairs non-idiomatic functionally-equivalent idiomatic for nine unique...

In this paper, a region-merging-based method is proposed for fast segmentation of amplitude-format synthetic aperture radar (SAR) images. It combines the existing initial partition by applying watershed transform to thresholded ratio edge strength map with region merging using new cost relative common boundary length penalty (RCBLP) and nearest neighbor graph (NNG) search minimal on adjacency (RAG). A statistical similarity measure, which scale-invariant approximately constant false alarm...

Volumetric videos offer a unique interactive experience and have the potential to enhance social virtual reality telepresence. Streaming volumetric multiple users remains challenge due its tremendous requirements of network computation resources. In this paper, we develop MuV2, an edge-assisted multi-user mobile video streaming system support important use cases such as tens students simultaneously consuming content in classroom. MuV2 achieves high scalability good quality through three...

5G Stand-Alone (SA) deployment is crucial for unlocking the full potential of 5G, providing significant improvements to mobile user experience and enabling development new applications. As operators start rolling out SA-5G market, there remains a lack comprehensive measurement studies, leaving many questions about its capabilities. To this end, we conducted timely in-field study in April 2023, covering two major US cities where T-Mobile has designated as dominant default radio access...

In order to reduce turbulence-induced scintillation and deal with alignment problems, a 2×2 multiple-input multiple-output (MIMO) underwater wireless optical communication (UWOC) system is proposed experimentally demonstrated. With help of the large divergence angle light beams field view (FOV) detectors, effect high-density air bubbles greatly eliminated. Simulation experimental results confirm that, in most intensity-modulation/direct-detection (IM/DD) MIMO-UWOC systems, repetition coding...

A pulsed fiber master oscillator power amplifier (MOPA), which is combined with second harmonic generation (SHG) and modulated by directly changing the current of low-power seed laser, designed in this paper to overcome 'green gap' semiconductor lasers difficulty obtaining high-power wide-bandwidth driving circuits. To decrease guard slot increase data rate a high-order pulse position modulation (PPM) system, pre-pulse shaping (PPS) utilized fluctuation power, caused gain dynamics...

It is vital for a city to monitor water quality in real time since the of has profound effect on residents' health. Unfortunately, it impossible human water's chemical composition frequently, which an impossibly demanding task, let alone time. Thus, taking advantage highly efficient system can be excellent solution. In this paper, we created called Real-time Intelligent Monitoring System Water Quality, enables responsive potential outbreak contamination and protect residents. The capable...

API developers have been working hard to evolve APIs provide more simple, powerful, and robust libraries. Although evolution has studied for multiple domains, such as Web Android development, deep learning frameworks not yet studied. It is very clear how why in frameworks, these are being heavily used industry. To fill this gap, we conduct a large-scale in-depth study on the of Tensorflow 2, which currently most popular framework. We first extract 6,329 changes by mining documentation 2...

In this study, a novel control strategy of three‐inline array tethered spacecraft formation is proposed, based on simplified non‐linear model around the equilibrium point. The stability analysed by using an interconnected system approach which deeply reveals coupling characteristic among three spacecraft. It shown that both individual laws and effects can achieve stability. problems fault‐tolerant fault propagation are further discussed. Simulation results validate effectiveness proposed methods.

The link alignment in underwater wireless optical communication (UWOC) systems is a knotty problem. diffractive deep neural network (D <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> NN) has shown great potential accomplishing tasks all optically these years. In this paper, 6-layer D NN proposed to alleviate the difficulties UWOC systems. Simulation results demonstrate that method can focus incident light with tilt angles from 0° 60°...

Application program interface (API) mapping is the key to success of code migration. Leveraging API documentation map APIs has been explored by previous studies, and recently, code-based learning approaches have become mainstream approach shown better results. However, often require a large amount training data (e.g., projects implemented using multiple languages or datasets), which are not widely available. In contrast, usually available, but we observed that much information in...

With the continuous evolution of online education, educational chatbots have become an indispensable help between teachers and learners. Due to unified answers, it is hard for replace part teacher's work, which should be more efficient than textbooks when retrieving knowledge establishing emotional connections. In this paper, we propose AI-based chatbot paradigm that introduces context recognition, learning experience, emotion management improve learners' confidence through dialogue template...