现实世界中人类流动性数据集的最新扩散促进了轨迹预测,需求预测,旅行时间估计和异常检测方面的地理空间和运输研究。但是,这些数据集还可以更广泛地对复杂的人类流动系统进行描述性分析。我们正式将生命分析模式定义为在线无监督异常检测的自然,可解释的扩展,我们不仅监视数据流的异常数据流,而且随着时间的推移会明确提取正常模式。为了学习生活的模式,我们在需要时适应了(GWR)的(GWR)从计算生物学和神经机构的研究到地理空间分析的新领域。与自组织图(SOM)有关的生物学启发的神经网络,在GPS流上迭代时会逐渐构建一组“记忆”或原型流量模式。然后,它将每个新观察结果与其先前的经验进行比较,从而诱导了在线,无监督的聚类和数据的异常检测。我们从Porto出租车数据集中挖掘出利益的模式,包括主要的公共假期和新发现的运输异常,例如节日和音乐会,据我们所知,这些疾病以前尚未在先前的工作中得到认可或报道。我们预计,在许多领域,包括智能城市,自动驾驶汽车以及城市规划和管理等许多领域,可以逐步学习正常和异常的道路运输行为的能力将是有用的。
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Humans and animals have the ability to continually acquire, fine-tune, and transfer knowledge and skills throughout their lifespan. This ability, referred to as lifelong learning, is mediated by a rich set of neurocognitive mechanisms that together contribute to the development and specialization of our sensorimotor skills as well as to long-term memory consolidation and retrieval. Consequently, lifelong learning capabilities are crucial for computational systems and autonomous agents interacting in the real world and processing continuous streams of information. However, lifelong learning remains a long-standing challenge for machine learning and neural network models since the continual acquisition of incrementally available information from non-stationary data distributions generally leads to catastrophic forgetting or interference. This limitation represents a major drawback for state-of-the-art deep neural network models that typically learn representations from stationary batches of training data, thus without accounting for situations in which information becomes incrementally available over time. In this review, we critically summarize the main challenges linked to lifelong learning for artificial learning systems and compare existing neural network approaches that alleviate, to different extents, catastrophic forgetting. Although significant advances have been made in domain-specific learning with neural networks, extensive research efforts are required for the development of robust lifelong learning on autonomous agents and robots. We discuss well-established and emerging research motivated by lifelong learning factors in biological systems such as structural plasticity, memory replay, curriculum and transfer learning, intrinsic motivation, and multisensory integration.
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Time series anomaly detection has applications in a wide range of research fields and applications, including manufacturing and healthcare. The presence of anomalies can indicate novel or unexpected events, such as production faults, system defects, or heart fluttering, and is therefore of particular interest. The large size and complex patterns of time series have led researchers to develop specialised deep learning models for detecting anomalous patterns. This survey focuses on providing structured and comprehensive state-of-the-art time series anomaly detection models through the use of deep learning. It providing a taxonomy based on the factors that divide anomaly detection models into different categories. Aside from describing the basic anomaly detection technique for each category, the advantages and limitations are also discussed. Furthermore, this study includes examples of deep anomaly detection in time series across various application domains in recent years. It finally summarises open issues in research and challenges faced while adopting deep anomaly detection models.
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需要了解和预测车辆的行为是运输领域中的公共和私人目标的基础,包括城市规划和管理,乘车共享服务以及智能运输系统。个人的喜好和预期目的地在整天,周和年中各不相同:例如,酒吧在晚上最受欢迎,海滩在夏天最受欢迎。尽管有这一原则,我们注意到葡萄牙波尔图的流行基准数据集的最新研究充其量只能通过纳入时间信息来提高预测性能的边际改善。我们提出了一种基于HyperNetworks的方法,该方法是一种元学习的变体(“学习学习”),其中神经网络学会根据输入来改变自己的权重。在我们的情况下,负责目标预测的权重有所不同,尤其是输入轨迹的时间。时间条件的权重显着改善了模型相对于消融研究和可比较的工作的误差,我们证实了我们的假设,即时间知识应改善对车辆预期目的地的预测。
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“轨迹”是指由地理空间中的移动物体产生的迹线,通常由一系列按时间顺序排列的点表示,其中每个点由地理空间坐标集和时间戳组成。位置感应和无线通信技术的快速进步使我们能够收集和存储大量的轨迹数据。因此,许多研究人员使用轨迹数据来分析各种移动物体的移动性。在本文中,我们专注于“城市车辆轨迹”,这是指城市交通网络中车辆的轨迹,我们专注于“城市车辆轨迹分析”。城市车辆轨迹分析提供了前所未有的机会,可以了解城市交通网络中的车辆运动模式,包括以用户为中心的旅行经验和系统范围的时空模式。城市车辆轨迹数据的时空特征在结构上相互关联,因此,许多先前的研究人员使用了各种方法来理解这种结构。特别是,由于其强大的函数近似和特征表示能力,深度学习模型是由于许多研究人员的注意。因此,本文的目的是开发基于深度学习的城市车辆轨迹分析模型,以更好地了解城市交通网络的移动模式。特别是,本文重点介绍了两项研究主题,具有很高的必要性,重要性和适用性:下一个位置预测,以及合成轨迹生成。在这项研究中,我们向城市车辆轨迹分析提供了各种新型模型,使用深度学习。
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Continual Learning (CL) is a field dedicated to devise algorithms able to achieve lifelong learning. Overcoming the knowledge disruption of previously acquired concepts, a drawback affecting deep learning models and that goes by the name of catastrophic forgetting, is a hard challenge. Currently, deep learning methods can attain impressive results when the data modeled does not undergo a considerable distributional shift in subsequent learning sessions, but whenever we expose such systems to this incremental setting, performance drop very quickly. Overcoming this limitation is fundamental as it would allow us to build truly intelligent systems showing stability and plasticity. Secondly, it would allow us to overcome the onerous limitation of retraining these architectures from scratch with the new updated data. In this thesis, we tackle the problem from multiple directions. In a first study, we show that in rehearsal-based techniques (systems that use memory buffer), the quantity of data stored in the rehearsal buffer is a more important factor over the quality of the data. Secondly, we propose one of the early works of incremental learning on ViTs architectures, comparing functional, weight and attention regularization approaches and propose effective novel a novel asymmetric loss. At the end we conclude with a study on pretraining and how it affects the performance in Continual Learning, raising some questions about the effective progression of the field. We then conclude with some future directions and closing remarks.
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人工智能(AI)和机器学习(ML)在网络安全挑战中的应用已在行业和学术界的吸引力,部分原因是对关键系统(例如云基础架构和政府机构)的广泛恶意软件攻击。入侵检测系统(IDS)使用某些形式的AI,由于能够以高预测准确性处理大量数据,因此获得了广泛的采用。这些系统托管在组织网络安全操作中心(CSOC)中,作为一种防御工具,可监视和检测恶意网络流,否则会影响机密性,完整性和可用性(CIA)。 CSOC分析师依靠这些系统来决定检测到的威胁。但是,使用深度学习(DL)技术设计的IDS通常被视为黑匣子模型,并且没有为其预测提供理由。这为CSOC分析师造成了障碍,因为他们无法根据模型的预测改善决策。解决此问题的一种解决方案是设计可解释的ID(X-IDS)。这项调查回顾了可解释的AI(XAI)的最先进的ID,目前的挑战,并讨论了这些挑战如何涉及X-ID的设计。特别是,我们全面讨论了黑匣子和白盒方法。我们还在这些方法之间的性能和产生解释的能力方面提出了权衡。此外,我们提出了一种通用体系结构,该建筑认为人类在循环中,该架构可以用作设计X-ID时的指南。研究建议是从三个关键观点提出的:需要定义ID的解释性,需要为各种利益相关者量身定制的解释以及设计指标来评估解释的需求。
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Concept drift primarily refers to an online supervised learning scenario when the relation between the input data and the target variable changes over time. Assuming a general knowledge of supervised learning in this paper we characterize adaptive learning process, categorize existing strategies for handling concept drift, overview the most representative, distinct and popular techniques and algorithms, discuss evaluation methodology of adaptive algorithms, and present a set of illustrative applications. The survey covers the different facets of concept drift in an integrated way to reflect on the existing scattered state-of-the-art. Thus, it aims at providing a comprehensive introduction to the concept drift adaptation for researchers, industry analysts and practitioners.
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AI的一个关键挑战是构建体现的系统,该系统在动态变化的环境中运行。此类系统必须适应更改任务上下文并持续学习。虽然标准的深度学习系统实现了最先进的静态基准的结果,但它们通常在动态方案中挣扎。在这些设置中,来自多个上下文的错误信号可能会彼此干扰,最终导致称为灾难性遗忘的现象。在本文中,我们将生物学启发的架构调查为对这些问题的解决方案。具体而言,我们表明树突和局部抑制系统的生物物理特性使网络能够以特定于上下文的方式动态限制和路由信息。我们的主要贡献如下。首先,我们提出了一种新颖的人工神经网络架构,该架构将活跃的枝形和稀疏表示融入了标准的深度学习框架中。接下来,我们在需要任务的适应性的两个单独的基准上研究这种架构的性能:Meta-World,一个机器人代理必须学习同时解决各种操纵任务的多任务强化学习环境;和一个持续的学习基准,其中模型的预测任务在整个训练中都会发生变化。对两个基准的分析演示了重叠但不同和稀疏的子网的出现,允许系统流动地使用最小的遗忘。我们的神经实现标志在单一架构上第一次在多任务和持续学习设置上取得了竞争力。我们的研究揭示了神经元的生物学特性如何通知深度学习系统,以解决通常不可能对传统ANN来解决的动态情景。
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操作网络通常依靠机器学习模型来进行许多任务,包括检测异常,推断应用程序性能和预测需求。然而,不幸的是,模型精度会因概念漂移而降低,从而,由于从软件升级到季节性到用户行为的变化,功能和目标预测之间的关系会发生变化。因此,缓解概念漂移是操作机器学习模型的重要组成部分,尽管它很重要,但在网络或一般的回归模型的背景下,概念漂移并未得到广泛的探索。因此,对于当前依赖机器学习模型的许多常见网络管理任务,如何检测或减轻它并不是一件好事。不幸的是,正如我们所展示的那样,通过使用新可用的数据经常重新培训模型可以充分缓解概念漂移,甚至可以进一步降低模型的准确性。在本文中,我们表征了美国主要大都市地区的大型蜂窝网络中的概念漂移。我们发现,概念漂移发生在许多重要的关键性能指标(KPI)上,独立于模型,训练集大小和时间间隔,因此需要采用实用方法来检测,解释和减轻它。为此,我们开发了特征(叶)的局部误差近似。叶检测到漂移;解释最有助于漂移的功能和时间间隔;并使用遗忘和过度采样来减轻漂移。我们使用超过四年的蜂窝KPI数据来评估叶子与行业标准的缓解方法。在美国,我们对主要的细胞提供商进行的初步测试表明,LEAF在各种KPI和模型上都是有效的。叶子始终优于周期性,并触发重新培训,同时还要降低昂贵的重新经营操作。
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预测性编码提供了对皮质功能的潜在统一说明 - 假设大脑的核心功能是最小化有关世界生成模型的预测错误。该理论与贝叶斯大脑框架密切相关,在过去的二十年中,在理论和认知神经科学领域都产生了重大影响。基于经验测试的预测编码的改进和扩展的理论和数学模型,以及评估其在大脑中实施的潜在生物学合理性以及该理论所做的具体神经生理学和心理学预测。尽管存在这种持久的知名度,但仍未对预测编码理论,尤其是该领域的最新发展进行全面回顾。在这里,我们提供了核心数学结构和预测编码的逻辑的全面综述,从而补充了文献中最新的教程。我们还回顾了该框架中的各种经典和最新工作,从可以实施预测性编码的神经生物学现实的微电路到预测性编码和广泛使用的错误算法的重新传播之间的紧密关系,以及对近距离的调查。预测性编码和现代机器学习技术之间的关系。
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Graph learning is a popular approach for performing machine learning on graph-structured data. It has revolutionized the machine learning ability to model graph data to address downstream tasks. Its application is wide due to the availability of graph data ranging from all types of networks to information systems. Most graph learning methods assume that the graph is static and its complete structure is known during training. This limits their applicability since they cannot be applied to problems where the underlying graph grows over time and/or new tasks emerge incrementally. Such applications require a lifelong learning approach that can learn the graph continuously and accommodate new information whilst retaining previously learned knowledge. Lifelong learning methods that enable continuous learning in regular domains like images and text cannot be directly applied to continuously evolving graph data, due to its irregular structure. As a result, graph lifelong learning is gaining attention from the research community. This survey paper provides a comprehensive overview of recent advancements in graph lifelong learning, including the categorization of existing methods, and the discussions of potential applications and open research problems.
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The literature on machine learning in the context of data streams is vast and growing. However, many of the defining assumptions regarding data-stream learning tasks are too strong to hold in practice, or are even contradictory such that they cannot be met in the contexts of supervised learning. Algorithms are chosen and designed based on criteria which are often not clearly stated, for problem settings not clearly defined, tested in unrealistic settings, and/or in isolation from related approaches in the wider literature. This puts into question the potential for real-world impact of many approaches conceived in such contexts, and risks propagating a misguided research focus. We propose to tackle these issues by reformulating the fundamental definitions and settings of supervised data-stream learning with regard to contemporary considerations of concept drift and temporal dependence; and we take a fresh look at what constitutes a supervised data-stream learning task, and a reconsideration of algorithms that may be applied to tackle such tasks. Through and in reflection of this formulation and overview, helped by an informal survey of industrial players dealing with real-world data streams, we provide recommendations. Our main emphasis is that learning from data streams does not impose a single-pass or online-learning approach, or any particular learning regime; and any constraints on memory and time are not specific to streaming. Meanwhile, there exist established techniques for dealing with temporal dependence and concept drift, in other areas of the literature. For the data streams community, we thus encourage a shift in research focus, from dealing with often-artificial constraints and assumptions on the learning mode, to issues such as robustness, privacy, and interpretability which are increasingly relevant to learning in data streams in academic and industrial settings.
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Understanding how biological neural networks carry out learning using spike-based local plasticity mechanisms can lead to the development of powerful, energy-efficient, and adaptive neuromorphic processing systems. A large number of spike-based learning models have recently been proposed following different approaches. However, it is difficult to assess if and how they could be mapped onto neuromorphic hardware, and to compare their features and ease of implementation. To this end, in this survey, we provide a comprehensive overview of representative brain-inspired synaptic plasticity models and mixed-signal CMOS neuromorphic circuits within a unified framework. We review historical, bottom-up, and top-down approaches to modeling synaptic plasticity, and we identify computational primitives that can support low-latency and low-power hardware implementations of spike-based learning rules. We provide a common definition of a locality principle based on pre- and post-synaptic neuron information, which we propose as a fundamental requirement for physical implementations of synaptic plasticity. Based on this principle, we compare the properties of these models within the same framework, and describe the mixed-signal electronic circuits that implement their computing primitives, pointing out how these building blocks enable efficient on-chip and online learning in neuromorphic processing systems.
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在智能交通系统中,交通拥堵异常检测至关重要。运输机构的目标有两个方面:监视感兴趣领域的一般交通状况,并在异常拥堵状态下定位道路细分市场。建模拥塞模式可以实现这些目标,以实现全市道路的目标,相当于学习多元时间序列(MTS)的分布。但是,现有作品要么不可伸缩,要么无法同时捕获MTS中的空间信息。为此,我们提出了一个由数据驱动的生成方法组成的原则性和全面的框架,该方法可以执行可拖动的密度估计来检测流量异常。我们的方法在特征空间中的第一群段段,然后使用条件归一化流以在无监督的设置下在群集级别识别异常的时间快照。然后,我们通过在异常群集上使用内核密度估计器来识别段级别的异常。关于合成数据集的广泛实验表明,我们的方法在召回和F1得分方面显着优于几种最新的拥塞异常检测和诊断方法。我们还使用生成模型来采样标记的数据,该数据可以在有监督的环境中训练分类器,从而减轻缺乏在稀疏设置中进行异常检测的标记数据。
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Current learning machines have successfully solved hard application problems, reaching high accuracy and displaying seemingly "intelligent" behavior. Here we apply recent techniques for explaining decisions of state-of-the-art learning machines and analyze various tasks from computer vision and arcade games. This showcases a spectrum of problem-solving behaviors ranging from naive and short-sighted, to wellinformed and strategic. We observe that standard performance evaluation metrics can be oblivious to distinguishing these diverse problem solving behaviors. Furthermore, we propose our semi-automated Spectral Relevance Analysis that provides a practically effective way of characterizing and validating the behavior of nonlinear learning machines. This helps to assess whether a learned model indeed delivers reliably for the problem that it was conceived for. Furthermore, our work intends to add a voice of caution to the ongoing excitement about machine intelligence and pledges to evaluate and judge some of these recent successes in a more nuanced manner.
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在基于人工神经网络的终身学习系统中,最大的障碍之一是在遇到新信息时无法保留旧知识。这种现象被称为灾难性遗忘。在本文中,我们提出了一种新型的连接主义架构,即顺序的神经编码网络,在从数据点流中学习时忘记了,并且与当今的网络不同,它不会通过流行的错误反向传播来学习。基于预测性处理的神经认知理论,我们的模型以生物学上可行的方式适应了突触,而另一个神经系统学会了指导和控制这种类似皮层的结构,模仿了一些基础神经节的某些任务连续控制功能。在我们的实验中,我们证明了与标准神经模型相比,我们的自组织系统经历的遗忘大大降低,表现优于先前提出的方法,包括基于排练/数据缓冲的方法,包括标准(SplitMnist,SplitMnist,Split Mnist等) 。)和定制基准测试,即使以溪流式的方式进行了训练。我们的工作提供了证据表明,在实际神经元系统中模仿机制,例如本地学习,横向竞争,可以产生新的方向和可能性,以应对终身机器学习的巨大挑战。
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我们提出了一种新的四管齐下的方法,在文献中首次建立消防员的情境意识。我们构建了一系列深度学习框架,彼此之叠,以提高消防员在紧急首次响应设置中进行的救援任务的安全性,效率和成功完成。首先,我们使用深度卷积神经网络(CNN)系统,以实时地分类和识别来自热图像的感兴趣对象。接下来,我们将此CNN框架扩展了对象检测,跟踪,分割与掩码RCNN框架,以及具有多模级自然语言处理(NLP)框架的场景描述。第三,我们建立了一个深入的Q学习的代理,免受压力引起的迷失方向和焦虑,能够根据现场消防环境中观察和存储的事实来制定明确的导航决策。最后,我们使用了一种低计算无监督的学习技术,称为张量分解,在实时对异常检测进行有意义的特征提取。通过这些临时深度学习结构,我们建立了人工智能系统的骨干,用于消防员的情境意识。要将设计的系统带入消防员的使用,我们设计了一种物理结构,其中处理后的结果被用作创建增强现实的投入,这是一个能够建议他们所在地的消防员和周围的关键特征,这对救援操作至关重要在手头,以及路径规划功能,充当虚拟指南,以帮助迷彩的第一个响应者恢复安全。当组合时,这四种方法呈现了一种新颖的信息理解,转移和综合方法,这可能会大大提高消防员响应和功效,并降低寿命损失。
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尽管人工神经网络(ANN)取得了重大进展,但其设计过程仍在臭名昭著,这主要取决于直觉,经验和反复试验。这个依赖人类的过程通常很耗时,容易出现错误。此外,这些模型通常与其训练环境绑定,而没有考虑其周围环境的变化。神经网络的持续适应性和自动化对于部署后模型可访问性的几个领域至关重要(例如,IoT设备,自动驾驶汽车等)。此外,即使是可访问的模型,也需要频繁的维护后部署后,以克服诸如概念/数据漂移之类的问题,这可能是繁琐且限制性的。当前关于自适应ANN的艺术状况仍然是研究的过早领域。然而,一种自动化和持续学习形式的神经体系结构搜索(NAS)最近在深度学习研究领域中获得了越来越多的动力,旨在提供更强大和适应性的ANN开发框架。这项研究是关于汽车和CL之间交集的首次广泛综述,概述了可以促进ANN中充分自动化和终身可塑性的不同方法的研究方向。
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这篇理论文章研究了如何在计算机中构建类似人类的工作记忆和思维过程。应该有两个工作记忆存储,一个类似于关联皮层中的持续点火,另一个类似于大脑皮层中的突触增强。这些商店必须通过环境刺激或内部处理产生的新表示不断更新。它们应该连续更新,并以一种迭代的方式进行更新,这意味着在下一个状态下,应始终保留一组共同工作中的某些项目。因此,工作记忆中的一组概念将随着时间的推移逐渐发展。这使每个状态都是对先前状态的修订版,并导致连续的状态与它们所包含的一系列表示形式重叠和融合。随着添加新表示形式并减去旧表示形式,在这些更改过程中,有些保持活跃几秒钟。这种持续活动,类似于人工复发性神经网络中使用的活动,用于在整个全球工作区中传播激活能量,以搜索下一个关联更新。结果是能够朝着解决方案或目标前进的联想连接的中间状态链。迭代更新在这里概念化为信息处理策略,一种思想流的计算和神经生理决定因素以及用于设计和编程人工智能的算法。
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