526 research outputs found

    Real-time Optimal Resource Allocation for Embedded UAV Communication Systems

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    We consider device-to-device (D2D) wireless information and power transfer systems using an unmanned aerial vehicle (UAV) as a relay-assisted node. As the energy capacity and flight time of UAVs is limited, a significant issue in deploying UAV is to manage energy consumption in real-time application, which is proportional to the UAV transmit power. To tackle this important issue, we develop a real-time resource allocation algorithm for maximizing the energy efficiency by jointly optimizing the energy-harvesting time and power control for the considered (D2D) communication embedded with UAV. We demonstrate the effectiveness of the proposed algorithms as running time for solving them can be conducted in milliseconds.Comment: 11 pages, 5 figures, 1 table. This paper is accepted for publication on IEEE Wireless Communications Letter

    Energy harvesting based two-way full-duplex relaying network over a Rician fading environment: performance analysis

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    Full-duplex transmission is a promising technique to enhance the capacity of communication systems. In this paper, we propose and investigate the system performance of an energy harvesting based two-way full-duplex relaying network over a Rician fading environment. Firstly, we analyse and demonstrate the analytical expressions of the achievable throughput, outage probability, optimal time switching factor, and symbol error ratio of the proposed system. In the second step, the effect of various parameters of the system on its performance is presented and investigated. In the final step, the analytical results are also demonstrated by Monte Carlo simulation. The numerical results proved that the analytical results and the simulation results agreed with each other.Web of Science68112311

    Multisource power splitting energy harvesting relaying network in half-duplex system over block Rayleigh fading channel: System performance analysis

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    Energy harvesting and information transferring simultaneously by radio frequency (RF) is considered as the novel solution for green-energy wireless communications. From that point of view, the system performance (SP) analysis of multisource power splitting (PS) energy harvesting (EH) relaying network (RN) over block Rayleigh-fading channels is presented and investigated. We investigate the system in both delay-tolerant transmission (DTT), and delay-limited transmission (DLT) modes and devices work in the half-duplex (HD) system. In this model system, the closed-form (CF) expressions for the outage probability (OP), system throughput (ST) in DLT mode and for ergodic capacity (EC) for DTT mode are analyzed and derived, respectively. Furthermore, CF expression for the symbol errors ratio (SER) is demonstrated. Then, the optimal PS factor is investigated. Finally, a Monte Carlo simulation is used for validating the analytical expressions concerning with all system parameters (SP).Web of Science81art. no. 6

    Copyright in Universities: An Exploratory Study from Vietnam

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    International law and the laws of most nations today acknowledge and safeguard the intellectual property rights of both organizations and individuals. This recognition serves to stimulate innovative and creative endeavors, facilitate the dissemination of scientific, technological, cultural, and artistic advancements, foster economic and societal development, and enhance the overall quality of life. Intellectual property assumes a critical role as a driving force behind innovation and creativity, fostering the growth of a nation's intellectual assets in terms of both quantity and value. This, in turn, contributes to bolstering creative capabilities and fostering a healthy competitive environment. Nevertheless, intellectual property rights violations are not uncommon, particularly in the context of higher education institutions in Vietnam. In this article, the authors employ qualitative research methods, following the "three-step test" outlined in the Berne Convention of 1971 for the protection of literary and artistic works, in conjunction with the stipulations of Vietnamese Intellectual Property Law. The results of this examination aid in the identification and location of infringements on the author's rights, such as inappropriate citation and plagiarism within university settings. Subsequently, the authors propose various solutions, which include legal adjustments, strategies for managing intellectual property, the establishment of cross-sectoral and inter-university networks, and the regulation of the responsibilities of scientific councils. These measures are intended to mitigate instances of intellectual property rights violations within Vietnamese universities in the present day. Keywords: Copyright, three-step test, intellectual property rights, infringement, universities… DOI: 10.7176/JLPG/137-02 Publication date:October 31st 202

    Risk Factors for IN-Hospital Seizure and New-Onset Epilepsy in Coiling and Clipping Treatment of Aneurysmal Subarachnoid Hemorrhage

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    OBJECTIVE: To identify risk factors associated with in-hospital seizures and new-onset epilepsy in patients with aneurysmal subarachnoid hemorrhage (SAH) who underwent coiling embolization or clipping surgery. METHODS: This retrospective descriptive study included 195 patients diagnosed with aneurysmal SAH and treated with coiling embolization or clipping surgery between January 2018 and June 2022. RESULTS: Among the 195 patients meeting inclusion criteria, 9 experienced an onset seizure at the time of SAH. In-hospital seizures were observed in 33 patients, of which 24 were electrographic seizures detected in 24 patients with suspected subclinical seizures. After 12 months of follow-up, 11 patients met criteria for diagnosis of epilepsy. The incidence of epilepsy after discharge at 12 months was 2.41% in the coiling group and 8.03% in the clipping group. The risk of in-hospital seizures was significantly higher in the clipping group (P = 0.007), although the difference was not statistically significant after 12 months of follow-up (P = 0.121). CONCLUSIONS: Epilepsy following aneurysmal SAH was relatively common. Clipping surgery and brain edema emerged as independent predictive factors for in-hospital seizures, while onset seizures and in-hospital seizures were identified as independent predictors of epilepsy during follow-up. Patients presenting with these risk factors may benefit from long-term electroencephalogram monitoring and should be considered for prophylactic antiepileptic drugs. Additionally, lumbar drainage proved effective in improving both early and late epileptic outcomes in the group with Fisher grades 3 and 4

    An evaluation of sulphur topdressing strategies in Eastland pastures : a thesis presented in partial fulfilment for the requirements for the degree of Master of Agricultural Science in Soil Science at Massey University

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    Two sampling surveys for soil and herbage, one in autumn and the second in the following spring, were carried out to assess the pasture sulphur status in the Eastland area of the North Island. A preliminary glasshouse experiment using ryegrass as an indicator plant was also conducted to determine which soil test method best estimated the plant available sulphur pool in the soils covered by the survey. In comparison with calcium chloride extractable sulphur, soil sulphur extracted with calcium phosphate solution was shown to relate well to the yield response of ryegrass. Thus a calcium phosphate extractant was used as the criterion of soil sulphur status in the survey. In most of the soils surveyed, the levels of phosphate-extractable sulphur tended to decrease with depth down to 30 cm and were not constant throughout the year. Levels were lower in spring than in autumn, possibly due to the leaching loss of sulphate and the slow mineralisation rate of soil organic sulphur during winter. The decrease in soil sulphate levels during winter was observed even at sites with low annual rainfall (900 - 1000 mm) and in soils with anion retention capacities as high as 70% as measured by the phosphate retention test. Although the levels of Olsen extractable soil phosphorus also tended to decrease over winter, this decrease in available phosphorus was not nearly as great as for sulphate, suggesting that sulphate, being the more weakly adsorbed anion, had been leached more readily. Soil sulphur levels in autumn also reflected the sulphur fertiliser history more markedly than those in spring, thus providing further evidence of sulphate leaching during winter. The results obtained from the herbage survey were consistent with those derived from the glasshouse study and soil survey in showing that the sulphur status of pasture herbage, whether expressed in terms of total sulphur, sulphate or N:S ratios was generally lower in spring than in autumn. The lower sulphur status of soil and herbage in spring suggests that if sulphur deficiencies do occur in the Eastland pastures, they may be most apparent in early spring. To confirm the suspected spring sulphur deficiency observed in the survey, five field trials were laid down in the spring of the following year on soils belonging to three New Zealand soil groups: a yellow-grey earth, an intergrade between yellow-grey and yellow-brown earths and a yellow-brown pumice soil. Significant yield responses to spring application of sulphur were recorded at three out of the five sites. These sulphur-responsive sites included both those where there had been no recent application of sulphate-containing fertiliser and also those which had received regular autumn applications of sulphate at rates of 25 to 33 kg S hā¹ annum̄¹. Spring application of sulphur-free nitrogen fertiliser greatly increased dry matter yield but did not appear to aggravate the effect of sulphur deficiency on pasture growth at the sulphur-deficient sites, as evidenced by the fact that yield responses to sulphur application in the presence of nitrogen fertiliser were of similar or lower magnitude than those obtained with sulphur in the absence of nitrogen fertiliser. However, spring application of sulphur-free nitrogen led to very wide N:S ratios (18:1 to 23:1) in mixed herbage at two sulphur-deficient sites. In such situations, there may be a decrease in the nutritive value of the extra feed produced by a tactical application of nitrogen fertiliser

    Learning from Pixels with Expert Observations

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    In reinforcement learning (RL), sparse rewards can present a significant challenge. Fortunately, expert actions can be utilized to overcome this issue. However, acquiring explicit expert actions can be costly, and expert observations are often more readily available. This paper presents a new approach that uses expert observations for learning in robot manipulation tasks with sparse rewards from pixel observations. Specifically, our technique involves using expert observations as intermediate visual goals for a goal-conditioned RL agent, enabling it to complete a task by successively reaching a series of goals. We demonstrate the efficacy of our method in five challenging block construction tasks in simulation and show that when combined with two state-of-the-art agents, our approach can significantly improve their performance while requiring 4-20 times fewer expert actions during training. Moreover, our method is also superior to a hierarchical baseline.Comment: Accepted at IROS-2023 (Detroit, USA), the first two authors contributed equall

    Power beacon-assisted energy harvesting in a half-duplex communication network under co-channel interference over a Rayleigh fading environment: Energy efficiency and outage probability analysis

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    In this time, energy efficiency (EE), measured in bits per Watt, has been considered as an important emerging metric in energy-constrained wireless communication networks because of their energy shortage. In this paper, we investigate power beacon assisted (PB) energy harvesting (EH) in half-duplex (HD) communication network under co-channel Interferer over Rayleigh fading environment. In this work, we investigate the model system with the time switching (TS) protocol. Firstly, the exact and asymptotic form expressions of the outage probability (OP) are analyzed and derived. Then the system EE is investigated and the influence of the primary system parameters on the system performance. Finally, we verify the correctness of the analytical expressions using Monte Carlo simulation. Finally, we can state that the simulation and analytical results are the same.Web of Science1213art. no. 257

    Prevalence of trichinellosis and cysticercosis in indigenous pigs from ethnic minorities for selected communes in the Central Highlands (Dak Lak)

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    Traditionally applied free grazing/roaming of pigs is a known risks factor for selected zoonoses such trichinellosis and cysticercosis which have the potential to cause long lasting health problems in affected humans with sporadic complications such as fatal encephalitis. The ban of free grazing in pigs due to recent policy changes may have contributed to a decrease of both zoonoses and consequently making pork from local or wild pigs safer for the consumer. Despite of the ban some farmers might still use free roaming management at least partly for certain age classes of their pigs. Information on the presence of these zoonoses in pigs produced by ethnic groups is lacking or not updated. Therefore, a serological survey was carried out to provide base line information on the presence of cysticercosis and/or trichinellosis in native pigs in selected communes of the Central Highlands as being part of the Cross CRP project “Scoping study to evaluate the potential of integrated indigenous pig systems to improve livelihoods and safe pork consumption for poor ethnic minority smallholders in the Central Highlands of Vietnam”. While the serological sampling was implemented by WASI all laboratory analysis were carried out by NIVR, a research institute with known experience on the diagnosis for both zoonoses in Vietnam. In addition NIVR provided a training on sample collection and storage
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