arXiv subjects

Ruikang Wang

Publications and source records attributed to Ruikang Wang.

4 recordsLinked to original sources

arXiv2024

Fairness-aware Age-of-Information Minimization in WPT-Assisted Short-Packet Data Collection for mURLLC

The technological landscape is rapidly evolving toward large-scale systems. Networks supporting massive connectivity through numerous Internet of Things (IoT) devices are at the forefront of this advancement. In this paper, we examine Wireless Power Transfer (WPT)-enabled networks, where a server requires to collect data from these IoT devices to compute a task with massive Ultra-Reliable and Low-Latency Communication (mURLLC) services.} We focus on information freshness, using Age-of-Information (AoI) as the key performance metric. Specifically, we aim to minimize the maximum AoI among IoT devices by optimizing the scheduling policy. Our analytical findings demonstrate the convexity of the problem, enabling efficient solutions. We introduce the concept of AoI-oriented cluster capacity and analyze the relationship between the number of supported devices and network AoI performance. Numerical simulations validate our proposed approach's effectiveness in enhancing AoI performance, highlighting its potential for guiding the design of future IoT systems requiring mURLLC services.

cs.IT↗

arXiv2023

Non-contact acoustic micro-tapping optical coherence elastography for quantification of corneal anisotropic elasticity: in vivo rabbit study

Purpose. To demonstrate accurate measurement of corneal elastic moduli in vivo with non-contact and non-invasive optical coherence elastography. Methods. Elastic properties (in-plane Young's modulus E and both in-plane, u, and out-of-plane, G, shear moduli) of rabbit cornea were quantified in vivo using non-contact dynamic Acoustic micro-Tapping Optical Coherence Elastography (AuT-OCE). The IOP-dependence of measured mechanical properties was explored in extracted whole globes following in vivo measurement. A nearly-incompressible transverse isotropic (NITI) model was used to reconstruct moduli from AuT-OCE data. Independently, cornea elastic moduli were also measured ex vivo with traditional, destructive mechanical tests (tensile extensometry and shear rheometry). Results. Our study demonstrates strong anisotropy of corneal elasticity in rabbits. The in-plane Young's modulus, computer as E=3u, was in the range of 20-44 MPa, whereas the out-of-plane shear modulus was in the range of 34-261 kPa. Both pressure-dependent ex vivo OCE and destructive mechanical tests performed on the same samples within an hour of euthanasia strongly support the results of AuT-OCE measurements. Conclusions. Non-contact AuT-OCE can non-invasively quantify cornea anisotropic elastic properties in vivo. Translational Relevance. As OCT is broadly accepted in Ophthalmology, these results suggest the potential for rapid translation of AuT-OCE into clinical practice. In addition, AuT-OCE can likely improve diagnostic criteria of ectatic corneal diseases, leading to early diagnosis, reduced complications, customized surgical treatment, and personalized biomechanical models of the eye.

physics.med-ph↗

arXiv2022

Non-contact acoustic micro-tapping optical coherence elastography for evaluating biomechanical changes in the cornea following UV/riboflavin collagen cross linking: ex vivo human study

Purpose: To evaluate changes in the anisotropic elastic properties of ex vivo human cornea treated with UV cross-linking (CXL) using non-contact acoustic micro-tapping Optical Coherence Elastography (AuT-OCE) Design: AuT performed on normal and CXL ex vivo human donor cornea Methods: Elastic properties of normal and UV CXL treated human corneas were quantified using non-contact acoustic micro-tapping Optical Coherence Elastography (AuT-OCE) Main Outcome Measures: Corneal elastic moduli (in-plane Young's, E, and out-of-plane shear, G) can be evaluated in both normal and CXL treated tissues, as well as during the CXL procedure using non-contact AuT-OCE. Results: CXL induced a significant increase in both the tensile and shear moduli in human cornea. The mean in the paired study (pre- and post-, n=7) of the in-plane Young's modulus, E=3u, increased from 19 MPa to 43 MPa while the out-of-plane shear modulus, G, increased from 188 kPa to 673 kPa. Mechanical tests in a subgroup support CXL-induced cornea moduli changes and generally agree with AuT-OCE. Conclusions: The human cornea is a highly anisotropic material where in-plane mechanical properties are very different from those out-of-plane. Non-contact AuT-OCE can measure changes in the anisotropic elastic properties in human cornea as a result of UV-CXL.

physics.med-ph↗

arXiv2021

Delineating corneal elastic anisotropy in a porcine model using non-contact optical coherence elastography and ex vivo mechanical tests

Objective: To compare non-contact acoustic micro-tapping optical coherence elastography (AuT-OCE) with destructive mechanical tests to confirm corneal elastic anisotropy. Design: Ex vivo, laboratory study with non-contact AuT-OCE followed by mechanical rheometry and extensometry. Subjects: Inflated cornea of whole-globe porcine eyes. Methods: A non-contact transducer was used to launch mechanical waves in the cornea that were imaged with phase-sensitive OCT at physiologically relevant pressures. Reconstruction of both Young's modulus (E) and out-of-plane shear modulus (G) in the cornea from experimental data was performed using a model of a nearly incompressible transversally isotropic (NITI) medium. Samples were then excised and parallel plate rheometry was performed to measure the shear modulus G. Corneal samples were then subjected to strip extensomety to measure the Young's modulus. Main Outcome Measures: Strong corneal anisotropy was confirmed with both AuT-OCE and mechanical tests, with the Young's and shear moduli differing by over an order of magnitude. These results show that AuT-OCE can quantify both moduli with a non-contact, non-invasive, clinically translatable technique.

physics.bio-ph↗