946 research outputs found

    Multiagent Bidirectionally-Coordinated Nets: Emergence of Human-level Coordination in Learning to Play StarCraft Combat Games

    Get PDF
    Many artificial intelligence (AI) applications often require multiple intelligent agents to work in a collaborative effort. Efficient learning for intra-agent communication and coordination is an indispensable step towards general AI. In this paper, we take StarCraft combat game as a case study, where the task is to coordinate multiple agents as a team to defeat their enemies. To maintain a scalable yet effective communication protocol, we introduce a Multiagent Bidirectionally-Coordinated Network (BiCNet ['bIknet]) with a vectorised extension of actor-critic formulation. We show that BiCNet can handle different types of combats with arbitrary numbers of AI agents for both sides. Our analysis demonstrates that without any supervisions such as human demonstrations or labelled data, BiCNet could learn various types of advanced coordination strategies that have been commonly used by experienced game players. In our experiments, we evaluate our approach against multiple baselines under different scenarios; it shows state-of-the-art performance, and possesses potential values for large-scale real-world applications.Comment: 10 pages, 10 figures. Previously as title: "Multiagent Bidirectionally-Coordinated Nets for Learning to Play StarCraft Combat Games", Mar 201

    Artefacts Removal from Optical Coherence Tomography Angiography

    Get PDF
    This paper presents a new approach for artefacts removal from optical coherence tomography angiography (OCTA). The artefacts mainly arise as a result of distortion due to eye movements during OCT scanning process. These distortions manifest themselves as visible motion artefacts when doctors review the enface image of OCTA data. To remove these artefacts, firstly we perform motion registration for the captured OCT volume data and subsequently perform motion correction to obtain the registered OCT data. Next, we compute the OCTA from the registered OCT data using an enhanced correlation mapping technique. Thereafter, we compute the enface image from the OCTA data. In the next step, we attempt to locate regions where there is misalignment in the OCT frames of the various B-scans. Finally, we attempt to restore the regions where correct data is postulated to be absent. Our experimental results demonstrate the effectiveness of our proposed approach

    急性曼陀罗中毒患者临床护理观察

    Get PDF
    Mandala is used medicinally to treat cough and asthma, conscious sedation. Entire individual plant is poisonous, and the toxic substances are hyoscyamine and scopolamine and atropine, etc. It is a rare case that patients were poisoned by Mandala in clinical practice. More reports were about the cases that patients were poisoned by seeds, fruit, leaf and flower. The toxicity would stimulate and restrain the central nervous system successively, block the reactions of acetylcholine, resist and paralyze the parasympathetic nerve. The paper discusses continuous blood purification treatment and clinical nursing of mandala poisoning patients by case analysis.曼陀罗内服可用来平喘止咳,镇静麻醉。曼陀罗全株有毒,毒性物质为莨菪碱、东莨菪碱和阿托品等。在临床中遇到的曼陀罗中毒罕见。有病例报道多为误食曼陀罗种子、果实、叶、花所致,其毒性作用是对中枢神经先兴奋后抑制,阻断乙酰胆碱反应,对抗和麻痹副交感神经。本文通过病例分析,探讨如何对曼陀罗中毒患者行连续性血液净化治疗、临床护理

    Capacity Analysis and Throughput Maximization of NOMA with Nonlinear Power Amplifier Distortion

    Full text link
    In future B5G/6G broadband communication systems, non-linear signal distortion caused by the impairment of transmit power amplifier (PA) can severely degrade the communication performance, especially when uplink users share the wireless medium using non-orthogonal multiple access (NOMA) schemes. This is because the successive interference cancellation (SIC) decoding technique, used in NOMA, is incapable of eliminating the interference caused by PA distortion. Consequently, each user's decoding process suffers from the cumulative distortion noise of all uplink users. In this paper, we establish a new and tractable PA distortion signal model based on real-world measurements, where the distortion noise power is a polynomial function of PA transmit power diverging from the oversimplified linear function commonly employed in existing studies. Applying the proposed signal model, we characterize the capacity rate region of multi-user uplink NOMA by optimizing the user transmit power. Our findings reveal a significant contraction in the capacity region of NOMA, attributable to polynomial distortion noise power. For practical engineering applications, we formulate a general weighted sum rate maximization (WSRMax) problem under individual user rate constraints. We further propose an efficient power control algorithm to attain the optimal performance. Numerical results show that the optimal power control policy under the proposed non-linear PA model achieves on average 13\% higher throughput compared to the policies assuming an ideal linear PA model. Overall, our findings demonstrate the importance of accurate PA distortion modeling to the performance of NOMA and provide efficient optimal power control method accordingly.Comment: The paper has been submitted for potential journal publication

    Anthriscifolcine A, a C18-diterpenoid alkaloid

    Get PDF
    The title compound, C26H39NO7, which was isolated from Delphinium anthriscifolium var. majus, has a lycoctonine carbon skeleton containing four six-membered rings (A, B, D and E) and three five-membered rings (C, F and G). Rings A, B and E adopt chair conformation, while ring D adopts a boat conformation. Rings C and F adopt envelope conformations

    Motion Correction in Optical Coherence Tomography for Multi-modality Retinal Image Registration

    Get PDF
    Optical coherence tomography (OCT) is a recently developed non-invasive imaging modality, which is often used in ophthalmology. Because of the sequential scanning in form of A-scans, OCT suffers from the inevitable eye movement. This often leads to mis-alignment especially among consecutive B-scans, which affects the analysis and processing of the data such as the registration of the OCT en face image to color fundus image. In this paper, we propose a novel method to correct the mis-alignment among consecutive B-scans to improve the accuracy in multi-modality retinal image registration. In the method, we propose to compute decorrelation from overlapping B-scans and to detect the eye movement. Then, the B-scans with eye movement will be re-aligned to its precedent scans while the rest of B-scans without eye movement are untouched. Our experiments results show that the proposed method improves the accuracy and success rate in the registration to color fundus images

    Chemical composition and anti-cholesterol activity of tea (Camellia sinensis) flowers from albino cultivars

    Get PDF
    Albino tea cultivars are mutant tea plants with altered metabolisms. Current studies focus on the leaves while little is known about the flowers. To evaluate tea flowers from different albino cultivars, the chemical composition and anti-cholesterol activity of tea flowers from three albino cultivars (i.e., Baiye No.1, Huangjinya, and Yujinxiang) were compared. According to the results, tea flowers from Yujinxiang had more amino acids but less polyphenols than tea flowers from the other two albino cultivars. A reduced content of procyanidins and a high chakasaponins/floratheasaponins ratio were characteristics of tea flowers from Yujinxiang. In vitro anti-cholesterol activity assays revealed that tea flowers from Yujinxiang exhibited stronger activity in decreasing the micellar cholesterol solubility, but not in cholesterol esterase inhibition and bile salt binding. It was noteworthy that there were no specific differences on the chemical composition and anti-cholesterol activity between tea flowers from albino cultivars and from Jiukeng (a non-albino cultivar). These results increase our knowledges on tea flowers from different albino cultivars and help food manufacturers in the cultivar selection of tea flowers for use

    Malaria incidence from 2005–2013 and its associations with meteorological factors in Guangdong, China

    Get PDF
    Background: The temporal variation of malaria incidence has been linked to meteorological factors in many studies, but key factors observed and corresponding effect estimates were not consistent. Furthermore, the potential effect modification by individual characteristics is not well documented. This study intends to examine the delayed effects of meteorological factors and the sub-population's susceptibility in Guangdong, China. Methods: The Granger causality Wald test and Spearman correlation analysis were employed to select climatic variables influencing malaria. The distributed lag non-linear model (DLNM) was used to estimate the non-linear and delayed effects of weekly temperature, duration of sunshine, and precipitation on the weekly number of malaria cases after controlling for other confounders. Stratified analyses were conducted to identify the sub-population's susceptibility to meteorological effects by malaria type, gender, and age group. Results: An incidence rate of 1.1 cases per 1,000,000 people was detected in Guangdong from 2005-2013. High temperature was associated with an observed increase in malaria incidence, with the effect lasting for four weeks and a maximum relative risk (RR) of 1.57 (95% confidence interval (CI): 1.06-2.33) by comparing 30°C to the median temperature. The effect of sunshine duration peaked at lag five and the maximum RR was 1.36 (95% CI: 1.08-1.72) by comparing 24 hours/week to 0 hours/week. A J-shaped relationship was found between malaria incidence and precipitation with a threshold of 150 mm/week. Over the threshold, precipitation increased malaria incidence after four weeks with the effect lasting for 15 weeks, and the maximum RR of 1.55 (95% CI: 1.18-2.03) occurring at lag eight by comparing 225 mm/week to 0 mm/week. Plasmodium falciparum was more sensitive to temperature and precipitation than Plasmodium vivax. Females had a higher susceptibility to the effects of sunshine and precipitation, and children and the elderly were more sensitive to the change of temperature, sunshine duration, and precipitation. Conclusion: Temperature, duration of sunshine and precipitation played important roles in malaria incidence with effects delayed and varied across lags. Climatic effects were distinct among sub-groups. This study provided helpful information for predicting malaria incidence and developing the future warning system.School of Nursin
    corecore