pattern detection

模式检测
  • 文章类型: Journal Article
    神经科学是一门快速发展的学科,旨在揭示人类大脑和思想的复杂运作。脑肿瘤,从非癌到恶性,由于存在100多种不同类型,因此构成了重大的诊断挑战。有效的治疗取决于早期对这些肿瘤的精确检测和分割。我们介绍了一种采用二进制卷积神经网络(BCNN)的尖端深度学习方法来解决这个问题。该方法用于分割10种最常见的脑肿瘤类型,并且是对仅限于分割四种类型的当前模型的显着改进。我们的方法从获取MRI图像开始,然后是详细的预处理阶段,其中图像使用自适应阈值方法和形态学运算进行二进制转换。这将为下一步准备数据,这是分割。分割识别肿瘤类型并根据其等级(等级I至等级IV)对其进行分类,并将其与健康脑组织区分开。我们还策划了一个独特的数据集,包括专门用于本研究的6,600张脑部MRI图像。我们提出的模型实现的整体性能为99.36%。我们模型的有效性被其卓越的性能指标所强调,达到99.40%的准确度,99.32%精度,99.45%召回,和一个99.28%的F-Measure在分割任务。
    Neuroscience is a swiftly progressing discipline that aims to unravel the intricate workings of the human brain and mind. Brain tumors, ranging from non-cancerous to malignant forms, pose a significant diagnostic challenge due to the presence of more than 100 distinct types. Effective treatment hinges on the precise detection and segmentation of these tumors early. We introduce a cutting-edge deep-learning approach employing a binary convolutional neural network (BCNN) to address this. This method is employed to segment the 10 most prevalent brain tumor types and is a significant improvement over current models restricted to only segmenting four types. Our methodology begins with acquiring MRI images, followed by a detailed preprocessing stage where images undergo binary conversion using an adaptive thresholding method and morphological operations. This prepares the data for the next step, which is segmentation. The segmentation identifies the tumor type and classifies it according to its grade (Grade I to Grade IV) and differentiates it from healthy brain tissue. We also curated a unique dataset comprising 6,600 brain MRI images specifically for this study. The overall performance achieved by our proposed model is 99.36%. The effectiveness of our model is underscored by its remarkable performance metrics, achieving 99.40% accuracy, 99.32% precision, 99.45% recall, and a 99.28% F-Measure in segmentation tasks.
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  • 文章类型: Journal Article
    背景:来自多个提供者的电子健康记录(EHR)数据通常表现出重要但令人费解和复杂的模式,患者发现这些模式难以识别和解释。然而,现有的面向患者的应用程序缺乏能力,以结合自动模式检测健壮和支持使患者的EHR数据的意义。此外,没有办法组织EHR数据的有效方式,适合病人的需要,使他们在现实生活中更可操作的设置。这些缺点往往导致患者健康状况的扭曲和不完整的图片,这可能导致次优的决策和行动,使患者处于危险之中。
    目的:我们的主要目标是调查患者的态度,需要,并使用有关自动支持的场景,以在他们的EHR数据中显示重要模式,并提供组织它们最适合患者需求的手段。
    方法:我们对14名参与者进行了一项探究式研究。在尖端应用的背景下提出,着重强调独立的EHR数据感知,叫做发现,我们将高级模型用于新功能,这些功能应该支持自动识别重要数据模式,并提供建议-警报-以及根据患者需求组织医疗记录的方法,就像相册里的照片一样.使用反身主题分析方法分析了合并的录音笔录和研究中的笔记。
    结果:警报和集合可用于提高认识,反射,规划,尤其是基于证据的患者-提供者沟通。此外,患者需要精心设计的自动模式检测,并提供安全可行的建议,为潜在威胁和积极进展提供了量身定制的警报环境。此外,患者希望贡献自己的数据(例如,进度笔记)和日志感觉,每日观察,和测量,以丰富含义,并使警报和集合更容易感知。根据调查结果,我们将警报重命名为报告,以更中性的语气,并提供了更深入地将报告上下文化的设计含义,以提高可操作性;自动生成更快速和详尽组织EHR数据的集合;使患者生成的各种格式的数据输入能够支持更粗略的组织,更丰富的模式检测,并从经验中学习;并使用报告和收藏来提高效率,可靠,以及共同的患者-提供者沟通。
    结论:患者需要有一种灵活而丰富的方式来组织和注释他们的EHR数据;从这些数据中获得积极和消极的见解;并在临床访问中或通过消息传递与他们的医生分享这些工件,以建立明确的目标的共享心理模型。商定的优先事项,和可行的行动。
    BACKGROUND: Electronic health record (EHR) data from multiple providers often exhibit important but convoluted and complex patterns that patients find hard and time-consuming to identify and interpret. However, existing patient-facing applications lack the capability to incorporate automatic pattern detection robustly and toward supporting making sense of the patient\'s EHR data. In addition, there is no means to organize EHR data in an efficient way that suits the patient\'s needs and makes them more actionable in real-life settings. These shortcomings often result in a skewed and incomplete picture of the patient\'s health status, which may lead to suboptimal decision-making and actions that put the patient at risk.
    OBJECTIVE: Our main goal was to investigate patients\' attitudes, needs, and use scenarios with respect to automatic support for surfacing important patterns in their EHR data and providing means for organizing them that best suit patients\' needs.
    METHODS: We conducted an inquisitive research-through-design study with 14 participants. Presented in the context of a cutting-edge application with strong emphasis on independent EHR data sensemaking, called Discovery, we used high-level mock-ups for the new features that were supposed to support automatic identification of important data patterns and offer recommendations-Alerts-and means for organizing the medical records based on patients\' needs, much like photos in albums-Collections. The combined audio recording transcripts and in-study notes were analyzed using the reflexive thematic analysis approach.
    RESULTS: The Alerts and Collections can be used for raising awareness, reflection, planning, and especially evidence-based patient-provider communication. Moreover, patients desired carefully designed automatic pattern detection with safe and actionable recommendations, which produced a well-tailored and scoped landscape of alerts for both potential threats and positive progress. Furthermore, patients wanted to contribute their own data (eg, progress notes) and log feelings, daily observations, and measurements to enrich the meaning and enable easier sensemaking of the alerts and collections. On the basis of the findings, we renamed Alerts to Reports for a more neutral tone and offered design implications for contextualizing the reports more deeply for increased actionability; automatically generating the collections for more expedited and exhaustive organization of the EHR data; enabling patient-generated data input in various formats to support coarser organization, richer pattern detection, and learning from experience; and using the reports and collections for efficient, reliable, and common-ground patient-provider communication.
    CONCLUSIONS: Patients need to have a flexible and rich way to organize and annotate their EHR data; be introduced to insights from these data-both positive and negative; and share these artifacts with their physicians in clinical visits or via messaging for establishing shared mental models for clear goals, agreed-upon priorities, and feasible actions.
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  • 文章类型: Journal Article
    最初,“无意义”和随机产生的声音可以通过曝光来学习。研究证明了这一点,如果随机确定的声音模式的重复与以前的试验中出现的声音相同,则可以更好地检测到它们。这个实验提出了关于这种学习的两个新问题。首先,熟悉重复检测上下文之外的声音是否有助于以后的表现?第二,当重复与干扰因素交织时,熟悉是否会增强性能?首先训练听众以将同步复杂音调序列(持续时间为210毫秒)的独特模式与具有相似质量的其他音调序列(熟悉阶段)进行分类。然后,他们的任务是在4.2s长的摘录(重复检测阶段)中检测与类似干扰物交错的重复模式呈现。熟悉模式(FamiliarFixed-FF),一个不熟悉的模式,在整个过程中保持固定(不熟悉的固定-UF),或在每个试验中唯一确定的模式(不熟悉的未固定-UU)可以重复呈现。与UF和UU模式相比,FF模式以更快的速度学习,并实现了更高的重复检测灵敏度。同样,FF模式还显示出比UF模式更陡的响应时间(RTs)学习斜率。数据表明,对“无意义”声音模式的熟悉程度(即,没有重复)即使在存在干扰物的情况下也可以促进重复检测。熟悉的影响在学习的潜力中变得最为明显。
    Initially \"meaningless\" and randomly generated sounds can be learned over exposure. This is demonstrated by studies where repetitions of randomly determined sound patterns are detected better if they are the same sounds presented on previous trials than if they are novel. This experiment posed two novel questions about this learning. First, does familiarization with a sound outside of the repetition detection context facilitate later performance? Second, does familiarization enhance performance when repeats are interleaved with distracters? Listeners were first trained to categorize a unique pattern of synchronous complex tone trains (210 ms in duration) from other tone trains with similar qualities (familiarization phase). They were then tasked to detect repeated pattern presentations interleaved with similar distracters in 4.2 s long excerpts (repetition detection phase). The familiarized pattern (Familiar Fixed - FF), an unfamiliar pattern that remained fixed throughout (Unfamiliar Fixed - UF), or patterns that were uniquely determined on each trial (Unfamiliar Unfixed - UU) could be presented as repeats. FF patterns were learned at a faster rate and achieved higher repetition detection sensitivity than UF and UU patterns. Similarly, FF patterns also showed steeper learning slopes in their response times (RTs) than UF patterns. The data show that familiarity with a \"meaningless\" sound pattern on its own (i.e., without repetition) can facilitate repetition detection even in the presence of distracters. Familiarity effects become most apparent in the potential for learning.
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  • 文章类型: Journal Article
    物联网(IoT)范式不断发展,和许多不同的物联网设备,如智能手机和智能电器,广泛应用于智慧工业和智慧城市。这种模式的好处是显而易见的,但是这些物联网环境带来了新的挑战,例如检测和打击针对网络物理系统的网络安全攻击。本文通过结合使用机器学习(ML)技术和复杂事件处理(CEP)来解决这些物联网系统中安全攻击的实时检测。在这方面,过去,我们提出了一种将ML与CEP集成在一起的智能架构,并且允许定义事件模式,以便不仅实时检测特定的物联网安全攻击,还有以前没有定义的新型攻击。我们目前的担忧,以及本文的主要目的,是为了确保架构不一定链接到特定的供应商技术,并且可以使用其他供应商技术实现,同时保持其正确的功能。我们还着手评估和比较替代实现的性能和优势。这就是为什么提出的体系结构是通过使用来自不同供应商的技术来实现的:首先,Mule企业服务总线(ESB)和EsperCEP引擎;其次,带有SiddhiCEP引擎的WSO2ESB。这两种实现都经过了性能和压力方面的测试,本文对它们进行了比较和讨论。获得的结果表明,这两种实现都是合适和有效的,但它们之间也存在显著差异:当架构使用两个消息代理主题并比较不同类型的事件时,基于Mule的架构会更快,当存在单个主题和一个事件类型时,基于WSO2的速度更快,系统工作量大。
    The Internet of Things (IoT) paradigm keeps growing, and many different IoT devices, such as smartphones and smart appliances, are extensively used in smart industries and smart cities. The benefits of this paradigm are obvious, but these IoT environments have brought with them new challenges, such as detecting and combating cybersecurity attacks against cyber-physical systems. This paper addresses the real-time detection of security attacks in these IoT systems through the combined used of Machine Learning (ML) techniques and Complex Event Processing (CEP). In this regard, in the past we proposed an intelligent architecture that integrates ML with CEP, and which permits the definition of event patterns for the real-time detection of not only specific IoT security attacks, but also novel attacks that have not previously been defined. Our current concern, and the main objective of this paper, is to ensure that the architecture is not necessarily linked to specific vendor technologies and that it can be implemented with other vendor technologies while maintaining its correct functionality. We also set out to evaluate and compare the performance and benefits of alternative implementations. This is why the proposed architecture has been implemented by using technologies from different vendors: firstly, the Mule Enterprise Service Bus (ESB) together with the Esper CEP engine; and secondly, the WSO2 ESB with the Siddhi CEP engine. Both implementations have been tested in terms of performance and stress, and they are compared and discussed in this paper. The results obtained demonstrate that both implementations are suitable and effective, but also that there are notable differences between them: the Mule-based architecture is faster when the architecture makes use of two message broker topics and compares different types of events, while the WSO2-based one is faster when there is a single topic and one event type, and the system has a heavy workload.
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  • 文章类型: Journal Article
    马尔可夫模型由于其固有的捕获隐藏在序列数据中的复杂时间依存关系的能力而被广泛用于分类序列聚类和分类。现有的马尔可夫模型基于下一个状态的概率取决于由连续状态组成的先前上下文/模式的隐含假设。这种限制阻碍了模型,因为一些模式,被噪音干扰,可能在连续形式中不够频繁,但经常以稀疏的形式出现,不能利用隐藏在顺序数据中的信息。稀疏模式对应于模式中的第一个和最后一个之间的一个或一些状态被通配符替换的模式,该通配符可以由状态集中的值的子集匹配。在本文中,我们提出了一个新的模型,推广了传统的马尔可夫方法,使其能够处理稀疏模式和自适应处理稀疏模式的长度,即允许具有可变通配符的可变长度模式。模型,称为动态阶数马尔可夫模型(DOMM),允许在序列和一组序列/簇之间导出新的相似性度量。DOMM从次频繁模式构建稀疏模式,这些模式包含被噪声掩盖的重要统计信息。要实现DOMM,我们提出了一种基于概率后缀树(PST)的稀疏模式检测器(SPD),能够发现稀疏和连续模式,然后我们开发了一个分裂的聚类算法,名为DMSC,用于分类序列聚类的动态顺序马尔可夫模型。在现实世界数据集上的实验结果表明了所提出的模型的有希望的性能。
    Markov models are extensively used for categorical sequence clustering and classification due to their inherent ability to capture complex chronological dependencies hidden in sequential data. Existing Markov models are based on an implicit assumption that the probability of the next state depends on the preceding context/pattern which is consist of consecutive states. This restriction hampers the models since some patterns, disrupted by noise, may be not frequent enough in a consecutive form, but frequent in a sparse form, which can not make use of the information hidden in the sequential data. A sparse pattern corresponds to a pattern in which one or some of the state(s) between the first and last one in the pattern is/are replaced by wildcard(s) that can be matched by a subset of values in the state set. In this paper, we propose a new model that generalizes the conventional Markov approach making it capable of dealing with the sparse pattern and handling the length of the sparse patterns adaptively, i.e. allowing variable length pattern with variable wildcards. The model, named Dynamic order Markov model (DOMM), allows deriving a new similarity measure between a sequence and a set of sequences/cluster. DOMM builds a sparse pattern from sub-frequent patterns that contain significant statistical information veiled by the noise. To implement DOMM, we propose a sparse pattern detector (SPD) based on the probability suffix tree (PST) capable of discovering both sparse and consecutive patterns, and then we develop a divisive clustering algorithm, named DMSC, for Dynamic order Markov model for categorical sequence clustering. Experimental results on real-world datasets demonstrate the promising performance of the proposed model.
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  • 文章类型: Journal Article
    The predictable rhythmic structure is important to most ecologically relevant sounds for humans, such as is found in the rhythm of speech or music. This study addressed the question of how rhythmic predictions are maintained in the auditory system when there are multiple perceptual interpretations occurring simultaneously and emanating from the same sound source. We recorded the electroencephalogram (EEG) while presenting participants with a tone sequence that had two different tone feature patterns, one based on the sequential rhythmic variation in tone duration and the other on sequential rhythmic variation in tone intensity. Participants were presented with the same sound sequences and were instructed to listen for the intensity pattern (ignore fluctuations in duration) and press a response key to detected pattern deviants (attend intensity pattern task); to listen to the duration pattern (ignore fluctuations in intensity) and make a button press to duration pattern deviants (attend duration pattern task), and to watch a movie and ignore the sounds presented to their ears (attend visual task). Both intensity and duration patterns occurred predictably 85% of the time, thus the key question involved evaluating how the brain treated the irrelevant feature patterns (standards and deviants) while performing an auditory or visual task. We expected that task-based feature patterns would have a more robust brain response to attended standards and deviants than the unattended feature patterns. Instead, we found that the neural entrainment to the rhythm of the standard attended patterns had similar power to the standard of the unattended feature patterns. In addition, the infrequent pattern deviants elicited the event-related brain potential called the mismatch negativity component (MMN). The MMN elicited by task-based feature pattern deviants had a similar amplitude to MMNs elicited by unattended pattern deviants that were unattended because they were not the target pattern or because the participant ignored the sounds and watched a movie. Thus, these results demonstrate that the brain tracks multiple predictions about the complexities in sound streams and can automatically track and detect deviations with respect to these predictions. This capability would be useful for switching attention rapidly among multiple objects in a busy auditory scene.
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  • 文章类型: Journal Article
    The promise of neuromorphic computing to develop ultra-low-power intelligent devices lies in its ability to localize information processing and memory storage in synaptic circuits much like the synapses in the brain. Spiking neural networks modeled using high-resolution synapses and armed with local unsupervised learning rules like spike time-dependent plasticity (STDP) have shown promising results in tasks such as pattern detection and image classification. However, designing and implementing a conventional, multibit STDP circuit becomes complex both in terms of the circuitry and the required silicon area. In this work, we introduce a modified and hardware-friendly STDP learning (named adaptive STDP) implemented using just 4-bit synapses. We demonstrate the capability of this learning rule in a pattern recognition task, in which a neuron learns to recognize a specific spike pattern embedded within noisy inhomogeneous Poisson spikes. Our results demonstrate that the performance of the proposed learning rule (94% using just 4-bit synapses) is similar to the conventional STDP learning (96% using 64-bit floating-point precision). The models used in this study are ideal ones for a CMOS neuromorphic circuit with analog soma and synapse circuits and mixed-signal learning circuits. The learning circuit stores the synaptic weight in a 4-bit digital memory that is updated asynchronously. In circuit simulation with Taiwan Semiconductor Manufacturing Company (TSMC) 250 nm CMOS process design kit (PDK), the static power consumption of a single synapse and the energy per spike (to generate a synaptic current of amplitude 15 pA and time constant 3 ms) are less than 2 pW and 200 fJ, respectively. The static power consumption of the learning circuit is less than 135 pW, and the energy to process a pair of pre- and postsynaptic spikes corresponding to a single learning step is less than 235 pJ. A single 4-bit synapse (capable of being configured as excitatory, inhibitory, or shunting inhibitory) along with its learning circuitry and digital memory occupies around 17,250 μm2 of silicon area.
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  • 文章类型: Journal Article
    UNASSIGNED: To define criteria for determining when preimplantation genetic testing for aneuploidy (PGT-A) results are suggestive of a potential balanced chromosomal rearrangement in the egg or sperm source and warrant karyotyping.
    UNASSIGNED: Performance evaluation of criteria developed to assess PGT-A results for patterns of imbalances suggestive of a balanced chromosomal rearrangement in the egg or sperm source.
    UNASSIGNED: A single PGT-A laboratory and multiple in vitro fertilization centers.
    UNASSIGNED: Reproductive couples who underwent routine PGT-A testing.
    UNASSIGNED: Karyotyping of reproductive couples for whom patterns of imbalances observed in PGT-A results suggested a balanced chromosomal rearrangement in the egg or sperm source.
    UNASSIGNED: Correct or incorrect flagging of predicted translocation in either the egg or sperm source based on chromosome analysis.
    UNASSIGNED: Proposed criteria correctly predicted a balanced reciprocal translocation in 97% of cases (n = 33), a (13;14) Robertsonian translocation in all cases (n = 3), and an inversion in all cases (n = 2). Other criteria evaluated were determined to be ineffective because of relatively low occurrences that met the criteria and/or low predictive value.
    UNASSIGNED: Our results showed that the proposed criteria were effective for evaluating patterns of imbalances observed in PGT-A results suggestive of a potential chromosomal rearrangement in the egg or sperm source. Our proposed criteria can be employed by clinicians in the in vitro fertilization setting in combination with a patient\'s reproductive history to identify PGT-A patients who are likely carriers of balanced chromosomal rearrangements.
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  • 文章类型: Journal Article
    光谱PCA(sPCA),与经典PCA相比,提供了在特定频带内识别有组织的时空模式并提取动态模式的优势。然而,在PC的频率分辨率和鲁棒性之间不可避免的权衡导致对噪声和过拟合的高灵敏度,这限制了对sPCA结果的解释。我们在这里提出了sPCA的简单非参数实现,使用连续解析Morlet小波作为具有良好频率分辨率的交叉谱矩阵的鲁棒估计器。为了提高结果的可解释性,特别是当同一频带内存在几种相似振幅的模式时,我们提出了复值特征向量的旋转,以优化它们的空间规律性(平滑性)。所开发的方法,称为旋转光谱PCA(RSPCA),在模拟传播波的合成数据上进行了测试,即使数据中存在高水平的噪声,也显示出令人印象深刻的性能。适用于全球历史地势高度(GPH)和海面温度(SST)每日时间序列,该方法准确地捕获了GPH和SST以及SST中低频(2-7年周期性)的厄尔尼诺-南方涛动(ENSO)中高频(3-60天周期)的大气Rossby波模式。在高频下,rsPCA成功地解混了识别的波,揭示具有强大传播动力学的空间相干模式。
    Spectral PCA (sPCA), in contrast to classical PCA, offers the advantage of identifying organized spatiotemporal patterns within specific frequency bands and extracting dynamical modes. However, the unavoidable trade-off between frequency resolution and robustness of the PCs leads to high sensitivity to noise and overfitting, which limits the interpretation of the sPCA results. We propose herein a simple nonparametric implementation of sPCA using the continuous analytic Morlet wavelet as a robust estimator of the cross-spectral matrices with good frequency resolution. To improve the interpretability of the results, especially when several modes of similar amplitude exist within the same frequency band, we propose a rotation of the complex-valued eigenvectors to optimize their spatial regularity (smoothness). The developed method, called rotated spectral PCA (rsPCA), is tested on synthetic data simulating propagating waves and shows impressive performance even with high levels of noise in the data. Applied to global historical geopotential height (GPH) and sea surface temperature (SST) daily time series, the method accurately captures patterns of atmospheric Rossby waves at high frequencies (3-60-day periods) in both GPH and SST and El Niño-Southern Oscillation (ENSO) at low frequencies (2-7-yr periodicity) in SST. At high frequencies the rsPCA successfully unmixes the identified waves, revealing spatially coherent patterns with robust propagation dynamics.
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  • 文章类型: Journal Article
    While anomaly detection is very important in many domains, such as in cybersecurity, there are many rare anomalies or infrequent patterns in cybersecurity datasets. Detection of infrequent patterns is computationally expensive. Cybersecurity datasets consist of many features, mostly irrelevant, resulting in lower classification performance by machine learning algorithms. Hence, a feature selection (FS) approach, i.e., selecting relevant features only, is an essential preprocessing step in cybersecurity data analysis. Despite many FS approaches proposed in the literature, cooperative co-evolution (CC)-based FS approaches can be more suitable for cybersecurity data preprocessing considering the Big Data scenario. Accordingly, in this paper, we have applied our previously proposed CC-based FS with random feature grouping (CCFSRFG) to a benchmark cybersecurity dataset as the preprocessing step. The dataset with original features and the dataset with a reduced number of features were used for infrequent pattern detection. Experimental analysis was performed and evaluated using 10 unsupervised anomaly detection techniques. Therefore, the proposed infrequent pattern detection is termed Unsupervised Infrequent Pattern Detection (UIPD). Then, we compared the experimental results with and without FS in terms of true positive rate (TPR). Experimental analysis indicates that the highest rate of TPR improvement was by cluster-based local outlier factor (CBLOF) of the backdoor infrequent pattern detection, and it was 385.91% when using FS. Furthermore, the highest overall infrequent pattern detection TPR was improved by 61.47% for all infrequent patterns using clustering-based multivariate Gaussian outlier score (CMGOS) with FS.
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