When Backpressure Meets Predictive Scheduling

Motivated by the increasing popularity of learning and predicting human user behavior in communication and computing systems, in this paper, we investigate the fundamental benefit of predictive scheduling, i.e., predicting and pre-serving arrivals, in controlled queueing systems. Based on a lookahead window prediction model, we first establish a novel equivalence between the predictive queueing system with a \emph{fully-efficient} scheduling scheme and an equivalent queueing system without prediction. This connection allows us to analytically demonstrate that predictive scheduling necessarily improves system delay performance and can drive it to zero with increasing prediction power. We then propose the \textsf{Predictive Backpressure (PBP)} algorithm for achieving optimal utility performance in such predictive systems. \textsf{PBP} efficiently incorporates prediction into stochastic system control and avoids the great complication due to the exponential state space growth in the prediction window size. We show that \textsf{PBP} can achieve a utility performance that is within $O(\epsilon)$ of the optimal, for any $\epsilon>0$, while guaranteeing that the system delay distribution is a \emph{shifted-to-the-left} version of that under the original Backpressure algorithm. Hence, the average packet delay under \textsf{PBP} is strictly better than that under Backpressure, and vanishes with increasing prediction window size. This implies that the resulting utility-delay tradeoff with predictive scheduling beats the known optimal $[O(\epsilon), O(\log(1/\epsilon))]$ tradeoff for systems without prediction

Spin alignment of vector mesons from quark dynamics in a rotating medium

Vorticities in heavy-ion collisions (HICs) are supposed to induce spin alignment and polarization phenomena of quarks and mesons. In this work, we analyze the spin alignment of vector mesons $\phi$ and $\rho$ induced by rotation from quark dynamics in the framework of the Nambu-Jona-Lasinio (NJL) model. The rotating angular velocity induces mass splitting of spin components for vector $\phi,\rho$ mesons $M_{\phi,\rho}(\Omega)\simeq M_{\phi,\rho}(\Omega=0)-s_{z}\Omega$. This behavior contributes to the spin alignment of vector mesons $\phi,\rho$ in an equilibrium medium and naturally explains the negative deviation of $\rho_{00}-1/3$ for vector mesons. Incidentally, the positive deviation of $\rho_{00}-1/3$ under the magnetic field can also be easily understood from quark dynamics.Comment: 12 pages, 8 figure

Ginkgetin aglycone exerts anti-osteoporotic effect via regulation of NOX4/Akt/PI3K pathway

Purpose: To investigate the protective effect of Ginkgetin aglycone (GA) on ovariectomy-induced osteoporosis in rats, as well as the mechanism of action involved. Methods: Adult female Wistar rats (n = 40) were separated into four group: normal control, ovariectomy (OVR), 100 mg GA/kg dose, and 200 mg GA/kg dose. The rats were ovariectomized using standard procedures, except for those in normal control group. Rats in the two treatment groups received 100 or 200 mg GA/kg orally for a period of 12 weeks. Biochemical assays were performed on the urine and blood. Markers of bone formation and mediators of inflammation were assessed. Bone microarchitectural changes were examined using micro-CT scanner, while Western blotting was used to determine the expressions of NOX4, NF-κB p65, PI3K, Akt and JNK proteins in rat femurs. Results: Phosphorus and calcium levels in the serum varied among different groups. Levels of calcium, phosphorus and creatinine decreased (p < 0.01) significantly to a greater extent in the urine of GA group than in that of OVR group (p < 0.05). Interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α) and osteocalcin (OC) levels and the activity of alkaline phosphatase (ALP) decreased more in GA group than in OVR group. In GA-treated group, bone mineral density (BMD) was enhanced in a dose dependent manner than OVR group (p < 0.05). Treatment with GA ameliorated altered bone microarchitecture in OVR rats. Treatment of osteoporotic rats with GA led to significant and dosedependent decrease in the expressions of JNK, NOX4, NF-κB p65 and PI3K, and (p < 0.05) increase in the expression of Akt in femur tissue. Conclusion: In conclusion, result of study proves the anti-osteoporotic activity of GA is exerted via regulation of NOX4/PI3K/Akt pathway

Assessment of Long-Term Watershed Management on Reservoir Phosphorus Concentrations and Export Fluxes.

Source water nutrient management to prevent eutrophication requires critical strategies to reduce watershed phosphorus (P) loadings. Shanxi Drinking-Water Source Area (SDWSA) in eastern China experienced severe water quality deterioration before 2010, but showed considerable improvement following application of several watershed management actions to reduce P. This paper assessed the changes in total phosphorus (TP) concentrations and fluxes at the SDWSA outlet relative to watershed anthropogenic P sources during 2005⁻2016. Overall anthropogenic P inputs decreased by 21.5% over the study period. Domestic sewage, livestock, and fertilizer accounted for (mean ± SD) 18.4 ± 0.6%, 30.1 ± 1.9%, and 51.5 ± 1.5% of total anthropogenic P inputs during 2005⁻2010, compared to 24.3 ± 2.7%, 8.8 ± 10.7%, and 66.9 ± 8.0% for the 2011⁻2016 period, respectively. Annual average TP concentrations in SDWSA decreased from 0.041 ± 0.019 mg/L in 2009 to 0.025 ± 0.013 mg/L in 2016, a total decrease of 38.2%. Annual P flux exported from SDWSA decreased from 0.46 ± 0.04 kg P/(ha·a) in 2010 to 0.25 ± 0.02 kg P/(ha·a) in 2016, a decrease of 44.9%. The success in reducing TP concentrations was mainly due to the development of domestic sewage/refuse collection/treatment and improved livestock management. These P management practices have prevented harmful algal blooms, providing for safe drinking water

Casing Pipe Damage Detection with Optical Fiber Sensors: A Case Study in Oil Well Constructions

Casing pipes in oil well constructions may suddenly buckle inward as their inside and outside hydrostatic pressure difference increases. For the safety of construction workers and the steady development of oil industries, it is critically important to measure the stress state of a casing pipe. This study develops a rugged, real-time monitoring, and warning system that combines the distributed Brillouin Scattering Time Domain Reflectometry (BOTDR) and the discrete fiber Bragg grating (FBG) measurement. The BOTDR optical fiber sensors were embedded with no optical fiber splice joints in a fiber-reinforced polymer (FRP) rebar and the FBG sensors were wrapped in epoxy resins and glass clothes, both installed during the segmental construction of casing pipes. In situ tests indicate that the proposed sensing system and installation technique can survive the downhole driving process of casing pipes, withstand a harsh service environment, and remain intact with the casing pipes for compatible strain measurements. The relative error of the measured strains between the distributed and discrete sensors is less than 12%. The FBG sensors successfully measured the maximum horizontal principal stress with a relative error of 6.7% in comparison with a cross multipole array acoustic instrument