美国和全球的两个主要死亡原因是中风和心肌梗塞。两者的根本原因是由破裂或侵蚀的不稳定的动脉粥样硬化斑块释放的,这些斑块阻塞了心脏(心肌梗塞)或大脑(中风)的血管。临床研究表明,在斑块破裂或侵蚀事件中,斑块组成比病变大小更重要。为了确定斑块组成,计算了3D心血管免疫荧光图像的各种细胞类型的斑块病变。但是,手动计算这些细胞是昂贵的,耗时的,并且容易发生人为错误。手动计数的这些挑战激发了对自动化方法进行定位和计算图像中细胞的需求。这项研究的目的是开发一种自动方法,以最少的注释工作在3D免疫荧光图像中准确检测和计数细胞。在这项研究中,我们使用弱监督的学习方法使用点注释来训练悬停网络分割模型,以检测荧光图像中的核。使用点注释的优点是,与像素的注释相比,它们需要更少的精力。为了使用点注释训练悬停的网络模型,我们采用了一种普遍使用的群集标记方法,将点注释转换为精确的细胞核二进制掩模。传统上,这些方法从点注释产生了二进制面具,使该物体周围的区域未标记(通常在模型训练中被忽略)。但是,这些区域可能包含重要信息,有助于确定细胞之间的边界。因此,我们在这些区域使用了熵最小化的损失函数,以鼓励模型在未标记区域上输出更自信的预测。我们的比较研究表明,使用我们的弱训练的悬停网络模型...
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While inferring common actor states (such as position or velocity) is an important and well-explored task of the perception system aboard a self-driving vehicle (SDV), it may not always provide sufficient information to the SDV. This is especially true in the case of active emergency vehicles (EVs), where light-based signals also need to be captured to provide a full context. We consider this problem and propose a sequential methodology for the detection of active EVs, using an off-the-shelf CNN model operating at a frame level and a downstream smoother that accounts for the temporal aspect of flashing EV lights. We also explore model improvements through data augmentation and training with additional hard samples.
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濒危语言的用户努力在数字化介导的世界中蓬勃发展。我们开发了一种自动化方法,用于评估ISO 639认可的每种语言在数字语言支持方面的表现。该评估是基于从143个数字工具的网站上删除支持语言的名称,以代表数字技术可以支持语言的各种方式。该方法使用Mokken量表分析来生成可解释的模型,以量化数字语言支持并在全球范围内监视它。
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在我们最近在加纳被动饮食监测的饮食评估现场研究中,我们收集了超过25万件野外图像。该数据集是一种持续的努力,旨在通过被动监控摄像头技术在低收入和中等收入国家中准确测量单个食物和营养摄入量。目前的数据集涉及加纳农村地区和城市地区的20个家庭(74个受试者),研究中使用了两种不同类型的可穿戴摄像机。一旦开始,可穿戴摄像机会不断捕获受试者的活动,该活动会产生大量的数据,以便在进行分析之前清洁和注释。为了简化数据后处理和注释任务,我们提出了一个新颖的自学学习框架,以将大量以自我为中心的图像聚集到单独的事件中。每个事件都由一系列时间连续和上下文相似的图像组成。通过将图像聚集到单独的事件中,注释者和营养师可以更有效地检查和分析数据,并促进随后的饮食评估过程。在带有地面真实标签的固定测试套装上验证,拟议的框架在聚集质量和分类准确性方面优于基准。
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Designing experiments often requires balancing between learning about the true treatment effects and earning from allocating more samples to the superior treatment. While optimal algorithms for the Multi-Armed Bandit Problem (MABP) provide allocation policies that optimally balance learning and earning, they tend to be computationally expensive. The Gittins Index (GI) is a solution to the MABP that can simultaneously attain optimality and computationally efficiency goals, and it has been recently used in experiments with Bernoulli and Gaussian rewards. For the first time, we present a modification of the GI rule that can be used in experiments with exponentially-distributed rewards. We report its performance in simulated 2- armed and 3-armed experiments. Compared to traditional non-adaptive designs, our novel GI modified design shows operating characteristics comparable in learning (e.g. statistical power) but substantially better in earning (e.g. direct benefits). This illustrates the potential that designs using a GI approach to allocate participants have to improve participant benefits, increase efficiencies, and reduce experimental costs in adaptive multi-armed experiments with exponential rewards.
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Modelling and forecasting real-life human behaviour using online social media is an active endeavour of interest in politics, government, academia, and industry. Since its creation in 2006, Twitter has been proposed as a potential laboratory that could be used to gauge and predict social behaviour. During the last decade, the user base of Twitter has been growing and becoming more representative of the general population. Here we analyse this user base in the context of the 2021 Mexican Legislative Election. To do so, we use a dataset of 15 million election-related tweets in the six months preceding election day. We explore different election models that assign political preference to either the ruling parties or the opposition. We find that models using data with geographical attributes determine the results of the election with better precision and accuracy than conventional polling methods. These results demonstrate that analysis of public online data can outperform conventional polling methods, and that political analysis and general forecasting would likely benefit from incorporating such data in the immediate future. Moreover, the same Twitter dataset with geographical attributes is positively correlated with results from official census data on population and internet usage in Mexico. These findings suggest that we have reached a period in time when online activity, appropriately curated, can provide an accurate representation of offline behaviour.
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The visual dimension of cities has been a fundamental subject in urban studies, since the pioneering work of scholars such as Sitte, Lynch, Arnheim, and Jacobs. Several decades later, big data and artificial intelligence (AI) are revolutionizing how people move, sense, and interact with cities. This paper reviews the literature on the appearance and function of cities to illustrate how visual information has been used to understand them. A conceptual framework, Urban Visual Intelligence, is introduced to systematically elaborate on how new image data sources and AI techniques are reshaping the way researchers perceive and measure cities, enabling the study of the physical environment and its interactions with socioeconomic environments at various scales. The paper argues that these new approaches enable researchers to revisit the classic urban theories and themes, and potentially help cities create environments that are more in line with human behaviors and aspirations in the digital age.
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Existing federated classification algorithms typically assume the local annotations at every client cover the same set of classes. In this paper, we aim to lift such an assumption and focus on a more general yet practical non-IID setting where every client can work on non-identical and even disjoint sets of classes (i.e., client-exclusive classes), and the clients have a common goal which is to build a global classification model to identify the union of these classes. Such heterogeneity in client class sets poses a new challenge: how to ensure different clients are operating in the same latent space so as to avoid the drift after aggregation? We observe that the classes can be described in natural languages (i.e., class names) and these names are typically safe to share with all parties. Thus, we formulate the classification problem as a matching process between data representations and class representations and break the classification model into a data encoder and a label encoder. We leverage the natural-language class names as the common ground to anchor the class representations in the label encoder. In each iteration, the label encoder updates the class representations and regulates the data representations through matching. We further use the updated class representations at each round to annotate data samples for locally-unaware classes according to similarity and distill knowledge to local models. Extensive experiments on four real-world datasets show that the proposed method can outperform various classical and state-of-the-art federated learning methods designed for learning with non-IID data.
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This is paper for the smooth function approximation by neural networks (NN). Mathematical or physical functions can be replaced by NN models through regression. In this study, we get NNs that generate highly accurate and highly smooth function, which only comprised of a few weight parameters, through discussing a few topics about regression. First, we reinterpret inside of NNs for regression; consequently, we propose a new activation function--integrated sigmoid linear unit (ISLU). Then special charateristics of metadata for regression, which is different from other data like image or sound, is discussed for improving the performance of neural networks. Finally, the one of a simple hierarchical NN that generate models substituting mathematical function is presented, and the new batch concept ``meta-batch" which improves the performance of NN several times more is introduced. The new activation function, meta-batch method, features of numerical data, meta-augmentation with metaparameters, and a structure of NN generating a compact multi-layer perceptron(MLP) are essential in this study.
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The existing methods for video anomaly detection mostly utilize videos containing identifiable facial and appearance-based features. The use of videos with identifiable faces raises privacy concerns, especially when used in a hospital or community-based setting. Appearance-based features can also be sensitive to pixel-based noise, straining the anomaly detection methods to model the changes in the background and making it difficult to focus on the actions of humans in the foreground. Structural information in the form of skeletons describing the human motion in the videos is privacy-protecting and can overcome some of the problems posed by appearance-based features. In this paper, we present a survey of privacy-protecting deep learning anomaly detection methods using skeletons extracted from videos. We present a novel taxonomy of algorithms based on the various learning approaches. We conclude that skeleton-based approaches for anomaly detection can be a plausible privacy-protecting alternative for video anomaly detection. Lastly, we identify major open research questions and provide guidelines to address them.
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