In this work, we study the problem of how to strike a balance between the QoS provisioning and the energy efficiency when a cooperative communication scheme is applied to a clustered wireless sensor ...network. Specifically, we first characterize the tradeoff by a multi-variable optimization problem, with the goal of balancing the outage performance and the network lifetime. Then, we horizontally decompose the problem into the concatenation of two subproblems: i) the long-haul transmit power per sensor node, and ii) the set of assisting cluster nodes. For the former one, an optimal long-haul transmit power solution is proposed based on the Lambert W function. The latter one is modeled as a coalition formation game, where the characteristic function is designed based on the combination of the former subproblem's results. Furthermore, an optimal algorithm is proposed by using a dynamic coalition formation process based on the best-reply process with trial opportunity. Extensive simulation results are presented to demonstrate the effectiveness of our proposed scheme.
This study investigated the distribution features of uranium-238 (238U), radium-226 (226Ra), thorium-232 (232Th), and potassium-40 (40K) and evaluated the associated environmental radiological ...hazards of the topsoil and river sediments in the Jinding lead-zinc (Pb-Zn) mine catchment from Southwest China. The activity concentrations of 238U, 226Ra, 232Th, and 40K ranged from 24.0 ± 2.29–60.3 ± 5.26 Bq.kg-1, from 32.5 ± 3.95–69.8 ± 3.39 Bq.kg-1, from 15.3 ± 2.24–58.3 ± 4.92 Bq.kg-1, and from 203 ± 10.2–1140 ± 27.4 Bq.kg-1, respectively. The highest activity concentrations for all these radionuclides were primarily found in the mining areas and decreased with increasing distance from the mining sites. The radiological hazard indices, including radium equivalent activity, absorbed gamma dose rate in the air, outdoor annual effective dose equivalent, annual gonadal dose equivalent, and excess lifetime cancer, revealed that the highest values were observed in the mining area and downstream, specifically in the vicinity of the ore body. These elevated values exceeded the global mean value but remained below the threshold value, suggesting that routine protection measures for Pb-Zn miners during production activities are sufficient. The correlation analysis and cluster analysis revealed strong associations between radionuclides such as 238U, 226Ra, and 232Th, indicating a common source of these radionuclides. The activity ratios of 226Ra/238U, 226Ra/232Th, and 238U/40K varied with distance, suggesting the influence of geological processes and lithological composition on their transport and accumulation. In the mining catchment areas, the variations in these activity ratios increased indicated the impact of limestone material dilution on the levels of 232Th, 40K, and 238U in the upstream region. Moreover, the presence of sulfide minerals in the mining soils contributed to the enrichment of 226Ra and the removal of 238U caused those activity ratios decreased in the mining areas. Therefore, in the Jinding PbZn deposit, the patterns of mining activities and surface runoff processes in the catchment area favored the accumulation of 232Th and 226Ra over 40K and 238U. This study provides the first case study on the geochemical distributions of natural radionuclides in a typical Mississippi Valley-type PbZn mining area and offers fundamental information on radionuclide migration and baseline radiometric data for PbZn deposits worldwide.
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•The spatial distribution features of radionuclides were firstly reported in a MVT Pb-Zn mining area.•The radiological exposure risk in the Pb-Zn mining area is lower than expected.•The distributions of 232Th, 40K and 238U were influenced by addition of limestone materials in the upstream of mining areas.•226Ra and 232Th were greatly accumulated relative to 40K and 238U in the downstream of mining areas.
Abstract Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) poses a major threat to the global swine industry, yet effective prevention and control measures remain elusive. This study ...unveils Nitazoxanide (NTZ) as a potent inhibitor of PRRSV both in vitro and in vivo. Through High-Throughput Screening techniques, 16 potential anti-PRRSV compounds are identified from a library comprising FDA-approved and pharmacopeial drugs. We show that NTZ displays strong efficacy in reducing PRRSV proliferation and transmission in a swine model, alleviating viremia and lung damage. Additionally, Tizoxanide (TIZ), the primary metabolite of NTZ, has been identified as a facilitator of NMRAL1 dimerization. This finding potentially sheds light on the underlying mechanism contributing to TIZ’s role in augmenting the sensitivity of the IFN-β pathway. These results indicate the promising potential of NTZ as a repurposed therapeutic agent for Porcine Reproductive and Respiratory Syndrome (PRRS). Additionally, they provide valuable insights into the antiviral mechanisms underlying NTZ’s effectiveness.
This article investigates the problem of distributed channel selection in opportunistic spectrum access (OSA) networks with partially overlapping channels (POC) using a game-theoretic learning ...algorithm. Compared with traditional non-overlapping channels (NOC), POC can increase the full-range spectrum utilization, mitigate interference and improve the network throughput. However, most existing POC approaches are centralized, which are not suitable for distributed OSA networks. We formulate the POC selection problem as an interference mitigation game. We prove that the game has at least one pure strategy NE point and the best pure strategy NE point minimizes the aggregate interference in the network. We characterize the achievable performance of the game by presenting an upper bound for aggregate interference of all NE points. In addition, we propose a simultaneous uncoupled learning algorithm with heterogeneous exploration rates to achieve the pure strategy NE points of the game. Simulation results show that the heterogeneous exploration rates lead to faster convergence speed and the throughput improvement gain of the proposed POC approach over traditional NOC approach is significant. Also, the proposed uncoupled learning algorithm achieves satisfactory performance when compared with existing coupled and uncoupled algorithms.
Recent advances of information technology and the low cost of computing devices make it possible to collect end users' true thermal sensations at the building operation stage. This enables us to ...build personalized thermal comfort model from a new aspect. This paper proposes a data-driven method to describe the personalized thermal comfort in ordinary office environment. The model structure shows the condition of heat balance of human body, with four personalized coefficients estimated by on-line voting data. The adjustable coefficients provide the freedom to capture the personal differences in thermal comfort requirement. In contrast, the well-known PMV model is only an average model, which cannot reflect such differences. The model performance is evaluated by a field experiment study. A personal energy saving potential analysis is also presented as one of the applications. Both the experiment results and simulation results demonstrate the high accuracy of the data-driven model and the feasibility of the application in investigating personal energy saving potentials.
•A learning model structure is developed to describe personalized thermal comfort.•The structure is based on human body thermal balance.•The model has satisfying performance in regression and prediction.•A case study demonstrates the applicability in analysis of personal energy saving.
This article explores the use of network-connected unmanned aerial vehicle (UAV) communications as a compelling solution to achieve high-rate information transmission and support ultra-reliable UAV ...remote command and control. We first discuss the use cases of UAVs and the resulting communication requirements, accompanied with a flexible architecture for network-connected UAV communications. Then, the signal transmission and interference characteristics are theoretically analyzed, and subsequently we highlight the design and optimization considerations, including antenna design, nonorthogonal multiple access communications, as well as network selection and association optimization. Finally, case studies are provided to show the feasibility of network-connected UAV communications.
We determined the concentrations and radiocarbon (14C) compositions of black carbon (BC) in the sediments of the East China Sea (ECS). The BC concentrations, which were in the range of 0.30–1.52mg/g, ...accounted for 12–65% of the total organic carbon (TOC). The distribution of BC in ECS sediments was controlled by factors such as grain size, distance from the coast, and deposition rate. Radiocarbon measurements of BC yielded ages of 6350–10,440 years before present (BP), suggesting that the percentage of BC derived from biomass combustion was in the range of 29–48%. The BC burial flux in sediments of the ECS was estimated to be ∼1.39×106t/yr, which was similar to burial fluxes reported for shelf sediments in other areas. However, the magnitude of the total BC sink was far greater than that of any other shelf regions studied to date, indicating the global importance of BC accumulation in the ECS, and the magnitude of BC input from large rivers (e.g., the Changjiang). The riverine delivery of BC to the ECS (73%) was far greater than that of atmospheric flux (27%). Further study of the BC cycle and the interactions of BC with other organic compounds in marginal seas was required to better understand the role of BC in the global carbon cycle.
This paper is focused on the investigation of fatigue failure mechanism for TC17 with surface roughness, which is the quantitative expression of surface micro-scratch. First, the designed fatigue ...tests for TC17 with different surface conditions are carried out to investigate the mechanism of fatigue failure behavior for TC17 with surface roughness. A modified formula is developed to evaluate the fatigue limit of TC17. Then, with the comprehensive application of S-N curve models and test results, the new finding of model parameters is adopted, leading to a fatigue life model of TC17 with surface roughness. Study of fatigue evaluation model of TC17 with surface roughness is significant in theoretical and engineering fatigue study.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Spectrum auction is one of the most effective solutions to allocate the spectrum resource following the market rules and has attracted much attention from both academia and industry. However, most of ...the existing studies assume that the spectrum buyers' demands are homogeneous and the interference relationship is fixed without any change with the variation of spectrum. Furthermore, the economical efficiency of auction outcome has not drawn enough attention. That motivates us to design an auction scheme to jointly consider the multi-demand of buyers, heterogeneous spectrum, and economical efficiency. In this paper, we propose a novel overlapping coalition formation-based double auction, called VERACITY, to address this problem. The auctioneer groups the conflict free buyers into the same coalition and allows a buyer to join multiple coalitions based on the heterogeneous demand. Dynamic overlapping coalition formation implemented by the auctioneer is to find the approximately optimal coalition structure corresponding to the economical efficiency outcome, i.e., maximizing the social welfare. Furthermore, we prove that VERACITY is individually rational, budget balanced, truthful, and economically efficient. Simulation results are presented to show the convergence and effectiveness of the proposed VERACITY.
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