Computational model

计算模型
  • 文章类型: Journal Article
    人工智能方法和技术创造性地支持开发和改进选择用于聚合物材料加工的切碎机的方法的过程。这允许优化选择标准的实现,这可能不仅包括与切碎效率和回收质量相关的指标,还包括能源消耗。本文的目的是选择具有独立规则提取的基于人工智能(AI)的分析方法,即,基于数据的方法(机器学习-ML)。这项研究考虑了描述切碎过程的真实数据集(特征矩阵1982行×40列),包括用于优化碎纸机能效参数的能耗。1982年的每个记录在一个。csv文件(特征向量)有40个数字除以逗号。数据被分成一个学习集(70%的数据),测试集(20%的数据),和一个验证集(10%的数据)。交叉验证显示最佳模型为LbfgsLogisticRegressionOva(0.9333)。这促进了智能切碎方法的基础的发展,在工业4.0范式中对聚合物材料的加工和回收进行了高水平的创新。
    Artificial intelligence methods and techniques creatively support the processes of developing and improving methods for selecting shredders for the processing of polymer materials. This allows to optimize the fulfillment of selection criteria, which may include not only indicators related to shredding efficiency and recyclate quality but also energy consumption. The aim of this paper is to select methods of analysis based on artificial intelligence (AI) with independent rule extraction, i.e., data-based methods (machine learning-ML). This study took into account real data sets (feature matrix 1982 rows × 40 columns) describing the shredding process, including energy consumption used to optimize the parameters for the energy efficiency of the shredder. Each of the 1982 records in a .csv file (feature vector) has 40 numbers divided by commas. The data were divided into a learning set (70% of the data), a testing set (20% of the data), and a validation set (10% of the data). Cross-validation showed that the best model was LbfgsLogisticRegressionOva (0.9333). This promotes the development of the basis for an intelligent shredding methodology with a high level of innovation in the processing and recycling of polymer materials within the Industry 4.0 paradigm.
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  • 文章类型: Published Erratum
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  • 文章类型: Journal Article
    目的:视网膜电图(ERG)是所有水平的视网膜光处理的总和反应,并在基础加工途径中表现出几个深刻的非线性。ERG的准确计算模型很重要,两者都是为了理解视网膜光传导到生态有用信号的多重过程,以及它们对视网膜疾病机制的识别和表征的诊断能力。有,然而,很少有ERG波形的计算模型,也没有一个能说明它随着时间的推移的全部特征。
    方法:本研究采用神经分析方法对ERG波形进行建模,定义为基于视网膜神经元发射器动力学的主要特征的计算模型。
    结果:从与Hood和Birch相同的一般原理出发,阐述了人类棒ERG的当前神经分析模型(VisNeurosci8(2):107-126,1992),但结合了Robson和Frishman对ERG产生的早期非线性阶段的最新理解(Prog视网膜眼Res39:1-22,2014)。因此,在Hood和Birch模型所基于的ERG闪光强度系列的六个不同波形特征中,它提供了比以前的杆响应模型更好的匹配。
    结论:神经分析方法扩展了以前的ERG分量波模型,并且可以被构造为提供ERG波形的整个时间进程的准确表征。因此,该方法有望促进对光响应的视网膜动力学的理论理解。
    OBJECTIVE: The electroretinogram (ERG) is the summed response from all levels of the retinal processing of light, and exhibits several profound nonlinearities in the underlying processing pathways. Accurate computational models of the ERG are important, both for understanding the multifold processes of light transduction to ecologically useful signals by the retina, and for their diagnostic capabilities for the identification and characterization of retinal disease mechanisms. There are, however, very few computational models of the ERG waveform, and none that account for the full extent of its features over time.
    METHODS: This study takes the neuroanalytic approach to modeling the ERG waveform, defined as a computational model based on the main features of the transmitter kinetics of the retinal neurons.
    RESULTS: The present neuroanalytic model of the human rod ERG is elaborated from the same general principles as that of Hood and Birch (Vis Neurosci 8(2):107-126, 1992), but incorporates the more recent understanding of the early nonlinear stages of ERG generation by Robson and Frishman (Prog Retinal Eye Res 39:1-22, 2014). As a result, it provides a substantially better match than previous models of rod responses in six different waveform features of the ERG flash intensity series on which the Hood and Birch model was based.
    CONCLUSIONS: The neuroanalytic approach extends previous models of the component waves of the ERG, and can be structured to provide an accurate characterization of the full timecourse of the ERG waveform. The approach thus holds promise for advancing the theoretical understanding of the retinal kinetics of the light response.
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  • 文章类型: Journal Article
    简介:诊所越来越需要易于部署的管状替代品来恢复输尿管和血管等结构的功能。尽管对各种材料进行了广泛的探索,合成和生物,最佳解决方案仍然难以捉摸。借鉴丰富的文学经验,迫切需要一种替代品,它不仅通过提供必要的信号和生长因子来模仿天然组织,而且还表现出适当的机械弹性和行为。方法:本研究旨在通过环和膜屈曲测试表征其天然构型的生物力学特性来评估猪输尿管的潜力。为了评估机械测试前后的组织形态以及将插入材料本构描述中的组织微观结构的最终改变,对样品进行组织学染色。进行了相应的计算分析,以模拟实验活动,以确定本构材料参数。结果:肌肉和胶原纤维没有任何损伤,仅在机械测试后压实,被证明了。实验测试(环和膜弯曲测试)显示了材料和几何形状的非线性以及天然猪输尿管的粘弹性行为。计算模型描述了输尿管组织的力学行为,材料模型可行。讨论:该分析将有助于将来与脱细胞组织进行比较,以评估细胞去除的侵袭性及其对微观结构的影响。计算模型可以为在后续模拟中进行管状替换的情况下预测请求的可靠工具奠定基础。
    Introduction: Clinics increasingly require readily deployable tubular substitutes to restore the functionality of structures like ureters and blood vessels. Despite extensive exploration of various materials, both synthetic and biological, the optimal solution remains elusive. Drawing on abundant literature experiences, there is a pressing demand for a substitute that not only emulates native tissue by providing requisite signals and growth factors but also exhibits appropriate mechanical resilience and behaviour. Methods: This study aims to assess the potential of porcine ureters by characterizing their biomechanical properties in their native configuration through ring and membrane flexion tests. In order to assess the tissue morphology before and after mechanical tests and the eventual alteration of tissue microstructure that would be inserted in material constitutive description, histological staining was performed on samples. Corresponding computational analyses were performed to mimic the experimental campaign to identify the constitutive material parameters. Results: The absence of any damages to muscle and collagen fibres, which only compacted after mechanical tests, was demonstrated. The experimental tests (ring and membrane flexion tests) showed non-linearity for material and geometry and the viscoelastic behaviour of the native porcine ureter. Computational models were descriptive of the mechanical behaviour ureteral tissue, and the material model feasible. Discussion: This analysis will be useful for future comparison with decellularized tissue for the evaluation of the aggression of cell removal and its effect on microstructure. The computational model could lay the basis for a reliable tool for the prediction of solicitation in the case of tubular substitutions in subsequent simulations.
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  • 文章类型: Journal Article
    人们的集体表现比个人更好,一种被称为集体利益的现象。为了追求利益,他们可以从以前的行为中学习,知道应该重视谁的初始意见,并发展将其视为集体的倾向。这种学习可能会影响人与人之间的大脑交流。为了测试这些假设,这项研究招募了参与者dyads进行感知任务,他们首先做出个人决定,然后做出集体决定。当个体决策存在分歧与分歧时,探索了参与者之间增强的人际大脑同步(IBS)协议。计算模型显示,参与者的二元发展了采用更高能力参与者的二元倾向,不是能力较低的人,作为他们的集体决定。大脑分析揭示了额极区域增强的IBS,运动前区域,门上回,和右颞叶顶叶连接。在没有校正的情况下,运动前IBS与二元倾斜和集体利益呈负相关。格兰杰因果关系分析进一步支持二元倾向与大脑间交流的负相关。这项研究强调了二元组合学会权衡个人的决定,导致二元倾斜,并探索相关的大脑间交流,提供对集体决策动态的见解。
    People perform better collectively than individually, a phenomenon known as the collective benefit. To pursue the benefit, they may learn from previous behaviors, come to know whose initial opinion should be valued, and develop the inclination to take it as the collective one. Such learning may affect interpersonal brain communication. To test these hypotheses, this study recruited participant dyads to conduct a perceptual task on which they made individual decisions first and then the collective one. The enhanced interpersonal brain synchronization (IBS) between participants was explored when individual decisions were in disagreement vs. agreement. Computational modeling revealed that participant dyads developed the dyad inclination of taking the higher-able participants\', not the lower-able ones\' decisions as their collective ones. Brain analyses unveiled the enhanced IBS at frontopolar areas, premotor areas, supramarginal gyri, and right temporal-parietal junctions. The premotor IBS correlated negatively with dyad inclination and collective benefit in the absence of correction. The Granger causality analyses further supported the negative relation of dyad inclination with inter-brain communication. This study highlights that dyads learn to weigh individuals\' decisions, resulting in dyad inclinations, and explores associated inter-brain communication, offering insights into the dynamics of collective decision-making.
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  • 文章类型: Journal Article
    目标:尽管人工耳蜗(CI)设备在过去几十年中得到了广泛使用和技术改进,仍需要进一步研究CI刺激的生物电基础。由不同CI制造商实施的各种刺激模式共存,但他们真正的临床益处仍不清楚,可能是由于所报告的高受试者间变异性,这使得CI结果的预测和刺激参数的最佳拟合具有挑战性。在这项研究中,开发了一个非常详细的完整的头部模型,其中包括耳蜗和电极阵列,以模拟耳蜗内电压和耳蜗外电流路径通过头部inCI刺激。
    方法:基于有限元方法的模拟是在单极,双极,三极,和部分三极模式,以及根尖,中间,和基础电极。模拟的变量包括:耳蜗内电压,电场(EF)衰减,头皮上的电势和通过头部的耳蜗外电流。为了更好地理解CI副作用,如面神经刺激,由耳蜗的寄生电流泄漏引起的,特别强调面神经EF的分析。
    结果:该模型合理地预测了以前在CI用户中报告的EF值和趋势。已经确定了通过头部和脑组织的新的相关耳蜗外电流通路。模拟结果还显示了在不同刺激模式和电极下,通过面神经的不同节段的EF的大小和分布的差异。依赖于神经和骨组织的电导率。
    结论:全头模型证明了对CI刺激中的耳蜗内和耳蜗外EF进行建模的有用工具。我们的发现可以证明对未来实验研究的设计有用,以对比刺激不同电极和CI模式时的FNS机制。开发的全头模型可免费供CI社区进一步研究和使用。
    OBJECTIVE: Despite the widespread use and technical improvement of cochlear implant (CI) devices over past decades, further research into the bioelectric bases of CI stimulation is still needed. Various stimulation modes implemented by different CI manufacturers coexist, but their true clinical benefit remains unclear, probably due to the high inter-subject variability reported, which makes the prediction of CI outcomes and the optimal fitting of stimulation parameters challenging. A highly detailed full head model that includes a cochlea and an electrode array is developed in this study to emulate intracochlear voltages and extracochlear current pathways through the head in CI stimulation.
    METHODS: Simulations based on the finite element method were conducted under monopolar, bipolar, tripolar, and partial tripolar modes, as well as for apical, medial, and basal electrodes. Variables simulated included: intracochlear voltages, electric field (EF) decay, electric potentials at the scalp and extracochlear currents through the head. To better understand CI side effects such as facial nerve stimulation, caused by spurious current leakage out from the cochlea, special emphasis is given to the analysis of the EF over the facial nerve.
    RESULTS: The model reasonably predicts EF magnitudes and trends previously reported in CI users. New relevant extracochlear current pathways through the head and brain tissues have been identified. Simulated results also show differences in the magnitude and distribution of the EF through different segments of the facial nerve upon different stimulation modes and electrodes, dependent on nerve and bone tissue conductivities.
    CONCLUSIONS: Full head models prove useful tools to model intra and extracochlear EFs in CI stimulation. Our findings could prove useful in the design of future experimental studies to contrast FNS mechanisms upon stimulation of different electrodes and CI modes. The full-head model developed is freely available for the CI community for further research and use.
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  • 文章类型: Journal Article
    脑深部电刺激(DBS)已成为晚期帕金森病(PD)的有效干预措施,但DBS的确切机制尚不清楚。在这次审查中,我们讨论星展银行的历史,基底神经节(BG)的解剖结构和内部结构,PD中BG的异常病理变化,以及计算模型如何帮助理解和推进DBS。我们还描述了两种类型的模型:数学理论模型和临床预测模型。数学理论模型模拟BG的神经元或神经网络,以阐明DBS背后的机械原理,虽然临床预测模型更多地关注患者的预后,帮助适应每个患者的治疗计划和推进新的电极设计。最后,我们提供对未来技术的见解和展望。
    Deep brain stimulation(DBS) has become an effective intervention for advanced Parkinson\'s disease(PD), but the exact mechanism of DBS is still unclear. In this review, we discuss the history of DBS, the anatomy and internal architecture of the basal ganglia (BG), the abnormal pathological changes of the BG in PD, and how computational models can help understand and advance DBS. We also describe two types of models: mathematical theoretical models and clinical predictive models. Mathematical theoretical models simulate neurons or neural networks of BG to shed light on the mechanistic principle underlying DBS, while clinical predictive models focus more on patients\' outcomes, helping to adapt treatment plans for each patient and advance novel electrode designs. Finally, we provide insights and an outlook on future technologies.
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  • 文章类型: Journal Article
    类别学习理论通常集中在基础类别结构如何影响学习者获得的类别表示。然而,关于其他因素如何影响学习和利用表征以及表征在学习过程中如何变化的研究有限。我们使用了一个新颖的“5/5”分类任务,该任务是从经过充分研究的5/4任务开发的,并增加了一个刺激,以澄清5/4原型中的歧义。我们使用包括计算建模在内的多种方法来识别参与者是否根据样本或原型表示进行分类。我们发现,总的来说,对于我们使用的刺激(类似机器人的示意性刺激),学习的最佳特点是使用原型。最重要的是,我们发现原型和范例策略的相对使用在学习过程中发生了变化,随着样本表示的使用减少,原型表示跨块增加。
    Theories of category learning have typically focused on how the underlying category structure affects the category representations acquired by learners. However, there is limited research as to how other factors affect what representations are learned and utilized and how representations might change across the time course of learning. We used a novel \"5/5\" categorization task developed from the well-studied 5/4 task with the addition of one more stimulus to clarify an ambiguity in the 5/4 prototypes. We used multiple methods including computational modeling to identify whether participants categorized on the basis of exemplar or prototype representations. We found that, overall, for the stimuli we used (schematic robot-like stimuli), learning was best characterized by the use of prototypes. Most importantly, we found that relative use of prototype and exemplar strategies changed across learning, with use of exemplar representations decreasing and prototype representations increasing across blocks.
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  • 文章类型: Journal Article
    公平是人类社会的基本价值,个人担心对自己和他人的不公平。然而,一场持久的辩论集中在自我不公平和他人不公平是否会引起共同或不同的神经心理过程。为了解决这个问题,我们将三人最后通牒游戏与计算建模和先进的神经影像分析技术相结合,认知,以及对自我和他人不公平的神经模式。我们的行为和计算结果表明,参与者对自我不公平的关注程度高于其他不公平。此外,自我不公平持续激活大脑区域,如前脑岛,背侧前扣带皮质,和背外侧前额叶皮层,跨越包含单变量激活的各种空间尺度,局部多元模式,和全脑多变量模式。这些区域在与基于公平的决策相关的情感和认知过程中建立了良好的联系。相反,其他不公平主要涉及枕中回。总的来说,我们的研究结果有力地支持了自我不公平和他人不公平之间不同的神经计算特征.
    Fairness is a fundamental value in human societies, with individuals concerned about unfairness both to themselves and to others. Nevertheless, an enduring debate focuses on whether self-unfairness and other-unfairness elicit shared or distinct neuropsychological processes. To address this, we combined a three-person ultimatum game with computational modeling and advanced neuroimaging analysis techniques to unravel the behavioral, cognitive, and neural patterns underlying unfairness to self and others. Our behavioral and computational results reveal a heightened concern among participants for self-unfairness over other-unfairness. Moreover, self-unfairness consistently activates brain regions such as the anterior insula, dorsal anterior cingulate cortex, and dorsolateral prefrontal cortex, spanning various spatial scales that encompass univariate activation, local multivariate patterns, and whole-brain multivariate patterns. These regions are well-established in their association with emotional and cognitive processes relevant to fairness-based decision-making. Conversely, other-unfairness primarily engages the middle occipital gyrus. Collectively, our findings robustly support distinct neurocomputational signatures between self-unfairness and other-unfairness.
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  • 文章类型: Journal Article
    背景:经颅电刺激(tES)通过附着在头皮上的表面电极在大脑中产生电场(或电流密度)。临床意义已被证明,尽管具有中等和不均匀的结果,部分原因是缺乏对所输送电流的控制。在过去的十年里,计算电场分析允许使用精确的解剖头部模型来估计和优化电场。这篇综述考察了最近的TES计算研究,在医疗应用中采用计算电场分析作为标准化程序的技术方面提供全面的背景。方法:设计了特定的搜索策略,以从WebofScience数据库中检索论文。论文最初是根据标题和摘要的正确性进行筛选的,然后根据其全部内容进行筛选,共进行了57项研究。结果:在电场的个人和人群水平分析中确定了最近的趋势,包括来自非神经典型个体的头部模型。还总结了先进的优化技术,这些技术可以对所需的聚焦度和电场方向进行高度控制。越来越多的证据表明,计算估计的电场与实际实验中观察到的响应之间存在相关性。结论:计算管道和优化算法已达到一定程度的成熟度,为改进tES实验设计和支持临床研究的响应的后验分析提供了理论基础。
    Background: Transcranial electrical stimulation (tES) generates an electric field (or current density) in the brain through surface electrodes attached to the scalp. Clinical significance has been demonstrated, although with moderate and heterogeneous results partly due to a lack of control of the delivered electric currents. In the last decade, computational electric field analysis has allowed the estimation and optimization of the electric field using accurate anatomical head models. This review examines recent tES computational studies, providing a comprehensive background on the technical aspects of adopting computational electric field analysis as a standardized procedure in medical applications. Methods: Specific search strategies were designed to retrieve papers from the Web of Science database. The papers were initially screened based on the soundness of the title and abstract and then on their full contents, resulting in a total of 57 studies. Results: Recent trends were identified in individual- and population-level analysis of the electric field, including head models from non-neurotypical individuals. Advanced optimization techniques that allow a high degree of control with the required focality and direction of the electric field were also summarized. There is also growing evidence of a correlation between the computationally estimated electric field and the observed responses in real experiments. Conclusions: Computational pipelines and optimization algorithms have reached a degree of maturity that provides a rationale to improve tES experimental design and a posteriori analysis of the responses for supporting clinical studies.
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