2,414 research outputs found
Learning quadratic games on networks
Individuals, or organizations, cooperate with or compete against one another in a wide range of practical situations. Such strategic interactions are often modeled as games played on networks, where an individual’s payoff depends not only on her action but also on that of her neighbors. The current literature has largely focused on analyzing the characteristics of network games in the scenario where the structure of the network, which is represented by a graph, is known beforehand. It is often the case, however, that the actions of the players are readily observable while the underlying interaction network remains hidden. In this paper, we propose two novel frameworks for learning, from the observations on individual actions, network games with linear-quadratic payoffs, and in particular, the structure of the interaction network. Our frameworks are based on the Nash equilibrium of such games and involve solving a joint optimization problem for the graph structure and the individual marginal benefits. Both synthetic and real-world experiments demonstrate the effectiveness of the proposed frameworks, which have theoretical as well as practical implications for understanding strategic interactions in a network environment
Classification of Overlapped Audio Events Based on AT, PLSA, and the Combination of Them
Audio event classification, as an important part of Computational Auditory Scene Analysis, has attracted much attention. Currently, the classification technology is mature enough to classify isolated audio events accurately, but for overlapped audio events, it performs much worse. While in real life, most audio documents would have certain percentage of overlaps, and so the overlap classification problem is an important part of audio classification. Nowadays, the work on overlapped audio event classification is still scarce, and most existing overlap classification systems can only recognize one audio event for an overlap. In this paper, in order to deal with overlaps, we innovatively introduce the author-topic (AT) model which was first proposed for text analysis into audio classification, and innovatively combine it with PLSA (Probabilistic Latent Semantic Analysis). We propose 4 systems, i.e. AT, PLSA, AT-PLSA and PLSA-AT, to classify overlaps. The 4 proposed systems have the ability to recognize two or more audio events for an overlap. The experimental results show that the 4 systems perform well in classifying overlapped audio events, whether it is the overlap in training set or the overlap out of training set. Also they perform well in classifying isolated audio events
Prediction of mechanical properties of composite materials based on convolutional neural network-long and short-term memory neural network
Convolutional neural networks (CNNs) have the advantage of processing complex images and extracting feature information from the images, while long and short term memory networks (LSTMs) are good at processing data with sequential features. In this paper, based on the deep material network, we propose to apply the CNN-LSTM neural network model to the prediction of mechanical properties of carbon fibre composites. Then the experimental results are compared with the model prediction results, and the results show that the CNN-LSTM prediction of the mechanical properties of carbon fibre composites is within 5% of the corresponding tensile mechanical experimental results, which proves the accuracy of the CNN-LSTM neural network model in the prediction of the mechanical properties of carbon fibre composites
An efficient method for reliability-based design optimization of structures under random excitation by mapping between reliability and operator norm
Reliability-based design optimization (RBDO) can fulfill both reliability and economic requirements by considering the stochastic properties of structure and excitation. However, the computational efficiency of this optimization is hindered by the nested loops involved in reliability analysis and optimization processes. In order to overcome this limitation, a novel method is proposed for structures subjected to random excitation, which is based on the mapping between operator norm and reliability index. This approach necessitates effectuating the transformation of the optimization objective from reliability indexes to operator norms with a small number of samples, thereby eliminating the laborious process of nested loops. It can effectively solve design optimization problems with reliability constraints, particularly for structures with explicit structural response under random excitation. Four examples are presented to demonstrate the effectiveness and applicability of the proposed method
Effect of Na doping on flux pinning of YBa1.9Na0.1Cu3O7-d
We have prepared Na-doped YBa2Cu3Oy (YBa1.9Na0.1Cu3Oy +40mol%Y211) (YBNCO)
and Na-free YBa2Cu3Oy (YBCO) samples by the Melt-Textured Growth (MTG) method
to study the effect of doped Na ion on flux pinning. The ac susceptibility
curves (acs) as well as the hysteresis loops were measured for the samples.
Then the effective pinning energy (U(T,Hdc,J)), irreversibility line (Hirr(T))
and critical current density (jc(Hdc)) were determined, where T, Hdc and J are
temperature, dc magnetic field and current density, respectively. We found
that, with Na doping, the Hirr(T) line shifted to lower temperature while the
Jc(Hdc) and U(T,Hdc,J) became smaller. It indicates that the Na ions play a
negative role in the flux pinning of YBCO. The appearance of the second peak in
the Jc(Hdc) curves and the enhancement of anisotropy in YBNCO further support
this finding.Comment: 7 pages, 7figures. Submited to Physica.
The Association Between Mitochondrial tRNAGlu Variants and Hearing Loss: A Case-Control Study
Xuejiao Yu,1 Sheng Li,2 Qinxian Guo,3 Jianhang Leng,3 Yu Ding3 1Department of Clinical Laboratory, Quzhou People’s Hospital, the Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou, Zhejiang Province, 324000, People’s Republic of China; 2Department of Otolaryngology, Quzhou People’s Hospital, the Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou, Zhejiang Province, 324000, People’s Republic of China; 3Central Laboratory, Hangzhou First People’s Hospital, Hangzhou, Zhejiang Province, 310006, People’s Republic of ChinaCorrespondence: Xuejiao Yu, Department of Clinical Laboratory, Quzhou People’s Hospital, the Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou, People’s Republic of China, Email [email protected] Yu Ding, Central Laboratory, Hangzhou First People’s Hospital, Hangzhou City, Zhejiang Province, 310006, People’s Republic of China, Email [email protected]: This study aimed to examine the frequencies of mt-tRNAGlu variants in 180 pediatric patients with non-syndromic hearing loss (NSHL) and 100 controls.Methods: Sanger sequencing was performed to screen for mt-tRNAGlu variants. These mitochondrial DNA (mtDNA) pathogenic mutations were further assessed using phylogenetic conservation and haplogroup analyses. We also traced the origins of the family history of probands carrying potential pathogenic mtDNA mutations. Mitochondrial functions including mtDNA content, ATP and reactive oxygen species (ROS) were examined in cells derived from patients carrying the mt-tRNAGlu A14692G and CO1/tRNASer(UCN) G7444A variants and controls.Results: We identified four possible pathogenic variants: m.T14709C, m.A14683G, m.A14692G and m.A14693G, which were found in NSHL patients but not in controls. Genetic counseling suggested that one child with the m.A14692G variant had a family history of NSHL. Sequence analysis of mtDNA suggested the presence of the CO1/tRNASer(UCN) G7444A and mt-tRNAGlu A14692G variants. Molecular analysis suggested that, compared with the controls, patients with these variants exhibited much lower mtDNA copy numbers, ATP production, whereas ROS levels increased (p< 0.05 for all), suggesting that the m.A14692G and m.G7444A variants led to mitochondrial dysfunction.Conclusion: mt-tRNAGlu variants are important risk factors for NSHL.Plain Language Summary: The main aim of our study was to explore the association between the mt-tRNAGlu variants and hearing loss. We found that m.T14709C, m.A14683G, m.A14692G and m.A14693G variants were associated with hearing impairments, these variants localized at extremely conserved nucleotides of mt-tRNAGlu and may result a failure in tRNA metabolism, furthermore, patients with mt-tRNAGlu variants exhibited much lower levels of mtDNA copy number, ATP as compared with controls, whereas ROS increased. As a result, mt-tRNAGlu variants may serve as biomarkers for mitochondrial deafness, and screening for tRNAGlu variants is recommended for early detection and diagnosis of mitochondrial deafness.Keywords: deafness, mitochondrial tRNAGlu variants, pediatrics, tRNA metabolis
Vibration control of offshore wind turbine under multiple hazards using single variable-stiffness tuned mass damper
With high flexibility and low damping, offshore wind turbines (OWTs) are prone to external vibrations such as wind, wave and earthquake, either attacked individually or as combined loading cases. This study proposes a semi-active variable-stiffness tuned mass damper (VSTMD) with magnetorheological elastomer (MRE) materials to mitigate undesired dynamic responses of OWT. A jacket supported OWT with MRE-TMD installed at the top of the tower is adopted as an example to demonstrate the effectiveness of the proposed design under multiple hazards. A semi-active frequency tracing algorithm is proposed through which the current-dependent stiffness of MRE-TMD is controlled by tracking the acceleration of OWT tower. The numerical results demonstrate that the semi-active MRE-TMD can effectively attenuate the dynamic responses of OWT under multi-hazard loadings, and it outperforms the passive TMD in reducing the peak and RMS displacements of tower structure. Robustness analysis of semi-active MRE-TMD is also validated by considering OWT sudden loss of partial stiffness under multiple-loadings
Acceleration of 60 MeV proton beams in the commissioning experiment of SULF-10 PW laser
We report the experimental results of the commissioning phase in the 10 PW
laser beamline of Shanghai Superintense Ultrafast Laser Facility (SULF). The
peak power reaches 2.4 PW on target without the last amplifying during the
experiment. The laser energy of 72\pm 9 J is directed to a focal spot of ~6
{\mu}m diameter (FWHM) in 30 fs pulse duration, yielding a focused peak
intensity around 2.0 \times 10^{21} W/cm^2. First laser-proton acceleration
experiment is performed using plain copper and plastic targets. High-energy
proton beams with maximum cut-off energy up to 62.5 MeV are achieved using
copper foils at the optimum target thickness of 4 {\mu}m via target normal
sheath acceleration (TNSA). For plastic targets of tens of nanometers thick,
the proton cut-off energy is approximately 20 MeV, showing ring-like or
filamented density distributions. These experimental results reflect the
capabilities of the SULF-10 PW beamline, e.g., both ultrahigh intensity and
relatively good beam contrast. Further optimization for these key parameters is
underway, where peak laser intensities of 10^{22}-10^{23} W/cm^2 are
anticipated to support various experiments on extreme field physics.Comment: 20 pages, 8 figures, regular article, This article has been submitted
to "High Power Laser Science and Engineering
Improving Lower Limb Function and Frailty in Frail Older Patients with Acute Myocardial Infarction After Percutaneous Coronary Intervention: A Randomized Controlled Study of Neuromuscular Electrical Stimulation
Xiamin Pu,1 Houqiang Huang,2 Xiaolei Zhao,3 Feng Liu,1 Yebo Leng,4 Ya Deng,5 Lingyi Huang,5 Xingchen Zhou,5 Fen Xu,1 Yongli Huang,6 Shengmin Guo2 1Department of Cardiovascular Medicine, The Affiliated Hospital, Southwest Medical University, Luzhou, 646000, People’s Republic of China; 2Department of Nursing, The Affiliated Hospital, Southwest Medical University, Luzhou, 646000, People’s Republic of China; 3Department of Hematology, The Affiliated Hospital, Southwest Medical University, Luzhou, 646000, People’s Republic of China; 4Department of Orthopedics, The Affiliated Hospital, Southwest Medical University, Luzhou, 646000, People’s Republic of China; 5School of Nursing, Southwest Medical University, Luzhou, 646000, People’s Republic of China; 6Department of Outpatient, The Affiliated Hospital, Southwest Medical University, Luzhou, People’s Republic of ChinaCorrespondence: Shengmin Guo, Department of Nursing, The Affiliated Hospital, Southwest Medical University, Luzhou, 646000, People’s Republic of China, Tel +86-13980255653, Email [email protected]: A global public health problem, frailty is closely associated with poor prognosis after percutaneous coronary intervention (PCI) in older patients with acute myocardial infarction (AMI). Although exercise intervention is the most commonly used method to reverse and alleviate frailty, its application is restricted in patients with acute myocardial infarction following PCI due to cardiovascular instability and autonomic imbalance. Consequently, there is a need for a new practical intervention to address frailty syndrome in these patients.Purpose: This study aimed to investigate the effect of neuromuscular electrical stimulation in frail older AMI patients post-PCI.Patients and Methods: A single-blind, randomized controlled trial was carried out in the Department of Cardiovascular Medicine from March to October 2023. A total of 100 eligible participants were randomly divided into two groups: experimental (n = 50) and control (n = 50) groups, respectively. Both groups received usual care. The experimental group underwent neuromuscular electrical stimulation (NMES) on bilateral quadriceps and gastrocnemius muscles for 30 minutes daily from day 1 to day 7 after surgery. The primary outcomes measured included the frailty score, lower limb muscle strength, and lower limb muscle quality. Secondary outcomes included the activities of daily living score, inflammatory markers, and length of hospital stay. All participants were included in an intention-to-treat analysis after the study ended.Results: The frailty scores of the two groups exhibited a gradual decrease over time, and the scores of the experimental group were lower than those of the control group at 4 and 7 days after surgery (P< 0.001). Concurrently, the lower limb muscle strength showed an increasing trend over the time in the experimental group and a decreasing trend in the control group, and the scores of the experimental group surpassed those of the control group (p< 0.001). Moreover, a statistical difference was observed in the lower limb muscle mass across the groups after 7 days postoperatively compared with baseline on both sides (p< 0.05).Conclusion: Neuromuscular electrical stimulation has the potential to enhance lower limb function and alleviate frailty in elderly patients with acute myocardial infarction after PCI. These findings introduce a novel intervention approach for frailty management in the elderly population.Keywords: acute myocardial infarction, older, frailty, neuromuscular electrical stimulation, PC
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