Enabling underwater wireless communications to conveniently interconnect various deployed devices for data transmission, information sharing, and networking is among the most crucial issues in marine networks. Apart from conventional acoustic, optical, electromagnetic techniques, magnetic induction (MI) communication, as a promising alternative, has drawn significant attentions recently due its inherent advantages predictable channel responses, negligible propagation delay, competitive...

Existing works have explored anchor deployment for autonomous underwater vehicles (AUVs) localization under the assumption that sound propagates straightly at a constant speed. Considering acoustic waves propagate along bent curves varying speeds in practice, it becomes much more challenging to determine proper configuration. In this paper, taking practical variability of speed into account, we investigate anchor-AUV geometry problem 3-D time-of-flight-based scenario from perspective...

Existing works have widely studied relay-aided underwater acoustic networks under some specialized relay distributions, e.g., equidistant and rectangular-grid. In this paper, we investigate two fundamental problems that which conditions a should be deployed where to deploy it if necessary in terms of the energy delay performance linear networks. To address these problems, first accurately approximate complicated effective bandwidth transmit power logarithm domain formulate an minimization...

Abstract Multi-objective genetic algorithms (MOGAs) are widely used for multi-reservoir systems’ optimization due to their high efficiency and fast convergence. However, the computational cost grows exponentially with expansion of systems increased dimensions problems, posing a great challenge operations. Therefore, it is important find suitable efficient multi-objective algorithm system optimization. In this study, three representative MOGAs were selected, namely Non-dominated Sorting...

Optimization design of centrifugal pump is a typical multiobjective optimization (MOO) problem. This paper presents an MOO with five decision variables and three objective functions, set pumps various impeller shroud shapes are studied by CFD numerical simulations. The important performance indexes for such as head, efficiency, required net positive suction head (NPSHr) investigated, the results indicate that geometry shape has strong effect on pump's indexes. Based these, radial basis...

This letter proposes an OFDM backscatter system that supports multi-tag concurrent transmission to improve spectral efficiency. Our key insight is a single subcarrier in signals sufficient decode the data of tag employs symbol-level modulation, leaving dozens subcarriers underutilized and redundant. Hence, by exploring equivalent channel contains cascaded data, we exploit redundancy for parallel decoding. Moreover, propose low-overhead estimation scheme channel. Experimental results show our...

We propose and experimentally demonstrate a novel all-optical microwave filter with high frequency selectivity. It is based on recirculating delay line (RDL) loop in which semiconductor optical amplifier (SOA) followed by tunable narrowband 1 × 2 10:90 coupler. Converted signal used as negative tap generated through wavelength conversion employing the cross-gain modulation (XGM) of amplified spontaneous emission (ASE) spectrum SOA. The converted circulating RDL can realize quality factor (Q)...

Abstract The optimized operation of an inter-basin water transfer system is a widely used approach to achieving regional resource allocation. costs transfers vary considerably, depending on the composition source, target audience and route distance transfer. This study proposes multi-scenario optimization model for transfer-supply systems that balances cost–benefit relationships. A two-objective first established including minimizing sum squared supply deficits cost transfers. Three...

Research on the co-optimization of soft robotic design and control requires rapid means for real-world validation. Existing creation pipelines do not allow swift prototyping robots to quickly test various configurations policies. This work proposes a pipeline iterative fabrication miniaturized modular silicone-elastomer-based fish. The allows simple iterations fishes with varying assist current research efforts development optimization methods. proposed fish can serve as standardized...

ABSTRACT Mathematical programming methods and modern intelligent algorithms are used to solve the optimized operation models of water storage projects. Classical mathematical prone curse dimensionality when size system increases. Intelligent improve computational efficiency a certain extent, but still suffer from defects such as unstable solutions easy fall into local optimizers. In this article, segmented trial-and-error algorithm is proposed obtain global optimizer while considering...

A measurement of carrier recovery time in semiconductor optical amplifiers (SOAs) based on dual pumps four-wave mixing (FWM) is presented. The results show the 91 ps, 79 ps and 63 at 120 mA, 180 mA 240 respectively, which agree to our expectation. experimental conversion efficiency keeps constant when spacing two varies within a small range.

Abstract A virtual space-time diversity soft direct-adaptation turbo euqalization (SDATEQ) is proposed for single-input-single-output (SISO) underwater acoustic (UWA) communications based on fractionally-spaced decision-feedback equalizer (SFSDFE) and time-reversal mirror (VTRM). The SFSDFE combined with recursive least-squares (RLS) algorithm employed to achieve space increases the mutual information (MI) of iterations faster convergence. Bidirectional structure VTRM exploited mitigate...

Marine-controlled source electromagnetic transmitter is an important equipment for the investigation of marine geology and exploration oil, gas, mineral resources in recent years. There are some problems from direct current–direct current (DC–DC) converter high power transmitter, load light, when output relatively small, lagging-leg switching cannot easily achieve zero voltage (ZVS), conversion efficiency heat requires improvement. This paper proposes a small ZVS circuits marine-controlled...

To providing an effective thruster for Solar-powered Autonomous Underwater Vehicle (SAUV), a new-style vectored is proposed. According to Lagrange equation, the dynamics equation of attained. Through designing solid model with 3D software and analyzing ADAMS, characteristics kinematics are acquired then problem additionally turning motion caused by rolling resolved. The design theory parameters SAUV will be supplied above-mentioned research.

We experimentally demonstrate all-optical clock recovery (CR) from the nonreturn-to-zero (NRZ) data without any preprocess measure. Multi-quantum-well (MQW) Fabry-Pérot semiconductor optical amplifier (FP-SOA) acts as dual role including both format converter and device. To achieve amplitude equalization of recovered pulses, a self-nonlinear polarization switching (SNPS) FP-SOA, two controllers (PCs) one beam splitter (PBS) is employed. Using presented scheme, stable low jitter 35.80 GHz...

This paper presents the theoretical development of negotiation a multi-underwater glider problem, where is called agent. Negotiation key point in multi-agent (multi-underwater glider) system, which aims to accomplish cooperation and coordination. How cooperate coordinate effectively remains be one most urgent problems study system too. The article mainly discusses how maintain coordination system. First, it introduces structure system; secondly, has raised function as realize cooperation. At...