Adaptive Three Layer Hybrid Reconfigurable Intelligent Surface for 6G Wireless Communication: Trade-offs and Performance

A potential candidate technology for the development of future 6G networks has been recognized as Reconfigurable Intelligent Surface (RIS). However, due to the variation in radio link quality, traditional passive RISs only accomplish a minimal signal gain in situations with strong direct links between user equipment (UE) and base station (BS). In order to get over this fundamental restriction of smaller gain, the idea of active RISs might be a suitable solution. In contrast to current passive RIS, which simply reflects and directs signals without any additional amplification, active RISs have the ability to enhance reflected signals by the incorporation of amplifiers inside its elements. However, with additional amplifiers, apart from the relatively complex attributes of RIS-assisted arrangements, the additional energy consumption of such technologies is often disregarded. So, there might be a tradeoff between the additional energy consumption for the RIS technologies and the overall gain acquired by deploying this potential advancement. The objective of this work is to provide a primary idea of a three-layer hybrid RIS-assisted configuration that is responsive to both active and passive RIS, as well as an additional dormant or inactive state. The single RIS structure should be capable of adjusting its overall configuration in response to fluctuations in transmit power and radio link quality. Furthermore, our fabricated passive RIS-assisted structure verifies a portion of the proposed idea, with simulations highlighting its advantages over standalone passive or active RIS-assisted technologies.Comment: Accepted for presentation and publication at the 8th IEEE Asia Pacific Conference on Wireless and Mobile (APWiMob) Conferenc

IMECE 2005-83000 AN EFFICIENT VOLUMETRIC-ERROR MEASUREMENT METHOD FOR FIVE-AXIS MACHINE TOOLS

ABSTRACT Accurate measurement of volumetric errors plays an important role for error compensation for multi-axis machines. The error measurements for volumetric errors of five-axis machines are usually very complex and costly than that for three-axis machines. In this study, a direct and simple measurement method using telescoping ball-bar system for volumetric errors for different types of five-axis machines was developed. The method using two-step measurement methodology and incorporating with derived error models, can quickly determine the five degrees-of-freedom (DOF) volumetric errors of five-axis machine tools. Comparing to most of the current used measurement methods, the proposed method provides the advantages of low cost, high efficiency, easy setup, and high accuracy

Analytic formulations for one-dimensional decay of rectangular homoepitaxial islands during coarsening on anisotropic fcc (110) surfaces

Submonolayer homoepitaxial fcc (110) systems display behavior reflecting strong anisotropy at lower temperatures, including one-dimensional decay during Ostwald ripening of rectangular islands maintaining constant width in the 〈001〉 direction. To appropriately describe this behavior, we first develop a refined continuum Burton-Cabrera-Frank formalism, which accounts for a lack of equilibration of island shape and importantly also for inhibited incorporation of adatoms at almost-faceted 〈1̄10〉 island edges through effective kinetic coefficients. This formalism is shown to describe accurately the adatom diffusion fluxes between islands and thus island evolution for a complex experimental island configuration, as confirmed by matching results from realistic atomistic simulations for this configuration. This approach also elucidates basic dependencies of flux on island geometry and temperature. Second, a further refinement is presented incorporating separate terrace and edge adatom density fields either in a continuum setting or alternatively in a spatially discrete diffusion equation setting. The second approach allows more flexibility and accuracy in accounting for edge-diffusion kinetics including corner rounding, a lack of equilibration of the edge adatom density atisland edges, and the effect of rare kinks onisland edges. Significantly, it suggests facile two-way corner rounding at the island periphery during island decay, contrasting the previous picture

Integrating Chinese Herbal Medicine into Conventional Care Was Related to Lower Risk of Sarcopenia Among Rheumatid Arthritis Patients: A Retrospective, Population-Based Study

Objective: Sarcopenia is a frequently observed comorbidity of rheumatoid arthritis (RA) due to the chronic activation of the innate immune system. Accumulating evidence has indicated that Chinese herbal medicine (CHM) safely suppresses proinflammatory pathways and controls inflammation-associated disease, but its effect in reducing the risk of developing sarcopenia among RA subjects has not been established. We conducted a population-level cohort study to compare the sarcopenia risk in patients with RA who use or do not use CHM. Methods: Using claims from a nationwide insurance database, we recruited patients with newly diagnosed RA and without sarcopenia between 2002 and 2010. Propensity score matching was applied to randomly select sets of CHM users and non-CHM users to compare the sarcopenia risk until the end of 2013. The risk of new-onset sarcopenia was assessed using the Cox proportional hazards model. Results: As compared to non-CHM users, those receiving CHM treatment had a lower incidence of sarcopenia (7.69 vs 9.83 per 1000 person-years). CHM was correlated with a decreased chance of sarcopenia after controlling for potential covariates. Notably, use of CHM for more than two years may diminish the risk of getting sarcopenia by about 47% when taken as prescribed. Prescriptions of several herbal formulae may benefit the reduction of sarcopenia risk, such as Yan-Hu-Suo, Bei-Mu, Da-Huang, Huang Qin, Ping-Wei- San (PWS), Shu-Jing-Huo-Xue-Tang (SJHXT) and Chuan-Xiong-Cha-Tiao-San (CXCTS). Conclusion: This study produced new evidence as it is the first to show that the longer duration of CHM use was correlated to reduced risk of sarcopenia in a dose-dependent manner, implying that CHM treatment could be embraced as a routine care strategy for preventing sarcopenia

Use of Chinese Herbal Medicine Was Related to Lower Risk of Osteoporotic Fracture in Sarcopenia Patients: Evidence from Population-Based Health Claims

Introduction: With population aging, sarcopenia and its accompanying risk of osteoporotic fracture has drawn increased attention. Nowadays, while Chinese herbal medicine (CHM) is often used as complementary therapy for many medical conditions, its effect against likelihood of osteoporotic fracture among sarcopenia subjects was not fully elucidated yet. We therefore conducted a population-level study to compare osteoporotic fracture risk for sarcopenia persons with or without CHM use. Methods: Using the patient record from a nationwide insurance database, we recruited persons with newly diagnosed sarcopenia and simultaneously free of osteoporotic fracture between 2000 and 2010. Propensity score matching was then applied to randomly select sets of CHM users and non-CHM users. All of them were tracked until end of 2013 to measure the incidence and adjusted hazard ratios (HRs) for new new-onset fracture in multivariable Cox proportional hazards model. Results: Compared to non-CHM users, the CHM users indeed had a lower incidence of osteoporotic fracture (121.22 vs 156.61 per 1000 person-years). Use of CHM correlated significantly with a lower fracture likelihood after adjusting for potential covariates, and those receiving CHM treatment for more than two years experienced a remarkably lower risk by 73%. Uses of several herbal formulae were correlated to reduced risk of osteoporotic fracture, such as Caulis Spatholobi, Xuduan, Duzhong, Danshen, Shu-Jing-Huo-Xue- Tang, Du-Huo-Ji-Sheng-Tang, Shao-Yao-Gan-Cao-Tang, and Shen-Tong-Zhu-Yu -Tang. Conclusion: Our study depicted that cumulative CHM exposure was inversely associated with osteoporotic fracture risk in a duration-dependent manner, implying that CHM treatment may be embraced as routine care in preventing incident osteoporotic fracture

Spin Relaxation in Single Layer Graphene with Tunable Mobility

Graphene is an attractive material for spintronics due to theoretical predictions of long spin lifetimes arising from low spin-orbit and hyperfine couplings. In experiments, however, spin lifetimes in single layer graphene (SLG) measured via Hanle effects are much shorter than expected theoretically. Thus, the origin of spin relaxation in SLG is a major issue for graphene spintronics. Despite extensive theoretical and experimental work addressing this question, there is still little clarity on the microscopic origin of spin relaxation. By using organic ligand-bound nanoparticles as charge reservoirs to tune mobility between 2700 and 12000 cm2/Vs, we successfully isolate the effect of charged impurity scattering on spin relaxation in SLG. Our results demonstrate that while charged impurities can greatly affect mobility, the spin lifetimes are not affected by charged impurity scattering.Comment: 13 pages, 5 figure

Adding Chinese Herbal Medicine to Routine Care is Associated With a Lower Risk of Rheumatoid Arthritis Among Patients With Asthma: A Population-Based Retrospective Cohort Study

Objective: Due to the shared pathogenesis of asthma and rheumatoid arthritis (RA), patients with asthma were found to have a higher risk of RA. While the benefits and safety of Chinese herbal medicine (CHM) for asthma have been reported, the scientific evidence regarding its effect on RA is limited. This longitudinal cohort study aimed to determine the relation between CHM use and RA risk in patients with asthma. Methods: Using the nationwide claims data, we enrolled 33,963 patients 20–80 years of age who were newly diagnosed with asthma and simultaneously free of RA between 2000 and 2007. From this sample, we utilized propensity score matching to create sets of participants as treatment and control groups, which comprised 13,440 CHM users and 13,440 non-CHM users. The incidence rate and hazard ratio (HR) for RA between the two groups were estimated at the end of 2013. A Cox proportional hazards model was constructed to examine the impact of the CHM use on the risk of RA. Results: The cumulative incidence of RA was substantially lower in the CHM user group. In the follow-up period, 214 patients in the CHM user group (1.92 per 1,000 person-years) and 359 patients in the non-CHM user group (2.92 per 1,000 person-years) developed RA (adjusted HR = 0.63, 95% confidence interval: 0.54–0.75). Of the commonly-prescribed formulae, nine CHM products were associated with a lower RA risk: Xiao-Qing-Long-Tang, Ma-Xing-Gan-Shi-Tang, Ding-Chuan-Tang, Xin-Yi-Qing-Fei-Tang, Bei Mu, Jie Geng, Xing Ren, Da Huang, and San Chi. Conclusion: This study found that patients with asthma who received CHM treatment, in addition to the conventional therapy, had a lower risk of RA. Use of CHM treatment may be integrated into conventional therapy to reduce subsequent RA risk among asthma patients