Relay-assisted free-space optical (FSO) communication systems are exploited as a means to mitigate the limiting effects of turbulence induced atmospheric scintillation. However, conventional ground relays stationary, and their optimal placement is not always feasible. Due mobility flexibility, unmanned aerial vehicles (UAVs) provide new opportunities for FSO relaying systems. In this paper, hovering UAV-based serial decode-and-forward system investigated. channel modelling such system, four...

The Western Black Sea (WBS) is now an area of active petroleum exploration, and several seismic surveys have been acquired to support the ongoing activity. Seismic imaging in WBS challenging due presence complex overburden, such as canyons, shallow gas channels, stratigraphy. Such overburden complexities create amplitude dimming wipeouts images cause structural distortions reservoir units. Conventional velocity model building migration methods are not optimal for addressing challenges....

Elastic properties from seismic data are important to determine subsurface hydrocarbon presence and have become increasingly for detailed reservoir characterization that aids derisk specific prospects. Traditional techniques extract elastic typically use linear inversion of imaged products (migrated angle stacks). In this research, we attempt get closer Tarantola's visionary goal full-wavefield (FWI) by directly obtaining 3D shot-gather with limited well information. First, present a...

Channel capacity bounds are derived for a point-to-point indoor visible light communications (VLC) system with signal-dependent Gaussian noise. Considering both illumination and communication, the non-negative input of VLC is constrained by peak average optical intensity constraints. Two scenarios taken into account: one scenario has constraints, other only constraint. For two scenarios, we derive closed-from expressions lower upper bounds. Specifically, bound using variational method...

In this paper we present initial results of applying Time-Reversed Acoustics (TRA) technology to salt-dome flank, seismic imaging. We created a set synthetic traces representing multilevel, walkaway VSP for model composed simplified Gulf Mexico vertical-velocity gradient and an embedded salt dome. first applied the concepts TRA create redatummed without having perform velocity analysis, moveout corrections, or complicated processing. Each trace approximates output zero-offset, downhole...

BACKGROUND AND OBJECTIVES: Aimed to investigate the safety, accuracy, and efficacy of stereo electroencephalography (SEEG) in children various ages, with particular emphasis on those younger than 3 years. There is limited guidance regarding whether SEEG can conducted very young children. METHODS: This retrospective study was between July 2018 August 2022. It involved 88 patients who underwent 99 robot-assisted procedures at our center. The were categorized into groups based their age time...

In this study, we investigate the impact of different wave‐mode separation approaches on TTI anisotropic elastic reverse time migration (RTM). We tested cheap but less accurate Helmholtz decomposition method as well expensive more pseudo‐derivative a simple 2D model. Our study shows that stacking operator associated with RTM algorithm can naturally remove most leaking‐mode artifacts generated by in media. Therefore, for purposes kinematic imaging, it is practically acceptable to use mode...

We describe a new shortcut strategy for imaging the sediments and salt edge around flank through an overburden canopy. tested its performance capabilities on 2D synthetic acoustic seismic data from Gulf of Mexico style model. first redatumed surface shots, using interferometry, walkaway vertical profile survey as if source receiver pairs had been located in borehole at positions receivers. This process creates effective downhole shot gathers by completely moving shots canopy, without any...

Electroencephalogram- (EEG-) based brain-computer interface (BCI) systems usually utilize one type of changes in the dynamics brain oscillations for control, such as event-related desynchronization/synchronization (ERD/ERS), steady state visual evoked potential (SSVEP), and P300 potentials. There is a recent trend to detect more than these signals system create hybrid BCI. However, this case, EEG data were always divided into groups analyzed by separate processing procedures. As result,...

We use the synthetic elastic Marmousi‐II ocean bottom cable (OBC) dataset to compare results from reverse‐time migration (RTM) and acoustic RTM. applied RTM pressure data horizontal vertical particle velocity for simulated OBC at sea bottom. The show clear improvement on P‐wave images compared images.

The Vp/Vs ratio can often be a good lithology indicator for variety of depositional environments. sands tends to lower than shales, irrespective fluid. Integration estimates with other seismic volumes reduce the risk associated predicting reservoir presence. In several instances, also used as input populating seismically constrained geologic models. this study we demonstrate feasibility applying elastic Full Wavefield Inversion (FWI) generate high-resolution ratio, using 3D marine streamer...

The use of acoustic FWI as a velocity model building tool has by now been well-documented in numerous publications. vast majority the published studies share two characteristics: (i) is only using refracted arrivals and very low frequencies, typically less than 10 Hz; (ii) models generated with are used to produce better migrations, but do not possess resolution be directly interpretable. We present here an field data application, that differs from common practice substantial ways: input...

We investigated the applicability of using Time Reversed Acoustics (TRA) technique, and thus whole waveform recorded signal, to locate microseismic events in a reservoir monitoring system (Lu, 2007). Reservoir has attracted lot attention over last twenty years. One challenges is locating that result from fluid injection fracturing processes. Conventionally, seismic event located arrival times P S phases. The picking could potentially be very time‐consuming difficult certain situations,...

Tight gas reservoirs are problematic to produce, often requiring multiple stages of hydraulic fracturing in order create connected pathways through which hydrocarbons may flow. In this paper, we propose a new methodology characterize the quality fractures. Using synthetic VSP and microseismic data, test concept that rock volume containing open, gas-filled fractures will scatter seismic energy more profusely than closed, nonproductive By measuring amount scattered time-lapse 3D study taken...

In previous studies, the receivers in indoor visible light communication (VLC) were usually fixed. However, reality, VLC have random locations and orientations. Therefore, it is important to consider these factors for performance analysis VLC. this paper, we a typical system with fixed transmitter receiver. Two types of are investigated: (1) those location (2) orientation. Based on established model, statistical characteristics channel obtained, closed-form expressions average capacity...

Background and objectivesThis case report investigates the application of intermittent Theta-Burst Stimulation (iTBS) in aphasia rehabilitation following a right hemisphere stroke.Case presentationA 52-year-old Chinese male with Broca's post-stroke was treated iTBS. His progress evaluated using Functional Near-Infrared Spectroscopy (fNIRS) behavioral assessments. Significant language function improvement noted, fNIRS showing increased activation language-related cortical areas altered...

Abstract Background Quantitative evaluation of position control ability in stroke patients is needed. Here we report a demonstration assessment and test-retest reliability during squat-stand activity on new system hemiparetic controls. Methods Sixty-two healthy adults thirty-four hemiparetics were enrolled. All the participants required to complete five repeated activities under three different conditions: partial weight support, standard bearing, resistance. The adults’ test was twice...

This paper focuses on an unmanned aerial vehicle (UAV) assisted hybrid free-space optical (FSO)/radio frequency (RF) communication system. Considering the rate imbalance between FSO and RF links, a buffer is employed at UAV. Initially, theoretical models of energy consumption throughput are obtained for Based these models, expression efficiency derived. Then, nonconvex trajectory optimization problem formulated by maximizing system under constraint, velocity acceleration start-end position...

The vibration signal of rolling bearings is a nonlinear and non-stationary signal, which affected by the working condition change background noise, reliability traditional feature extraction methods fault identification low. In order to effectively extract vectors improve accuracy identification, we propose new diagnosis method based on noise eliminated ensemble empirical mode decomposition robust unsupervised selection with local preservation (NEEEMD-RUSLP) binary tree least squares twin...

Background: Cerebral ischemic stroke (CIS) is a common cerebrovascular disease. The purpose of this study was to investigate the potential mechanism hypoxia and immune-related genes in CIS. Methods: All data were downloaded from public databases. Hub mRNAs identified by differential expression analysis, WGCNA analysis machine learning. used construct classification models. Pearson correlation analyze between hub immune cell infiltration. Finally, SAP30 selected for verification HMC3 cells....