这项研究提出了一种基于深度学习的超声(US)图像引导放射疗法的跟踪方法。拟议的级联深度学习模型由注意力网络,基于掩模区域的卷积神经网络(Mask R-CNN)和长期短期记忆(LSTM)网络组成。注意网络从美国图像到可疑的具有里程碑意义的运动区域,以减少搜索区域。然后,面膜R-CNN在减少区域中产生多个利益区域(ROI)建议,并通过三个网络头确定拟议的地标:边界框回归,提案分类和地标分段。 LSTM网络对连续的图像框架之间的时间关系建模,以进行边界框回归和建议分类。为了合并最终建议,根据顺序框架之间的相似性设计选择方法。该方法在肝脏美国跟踪数据集中测试了医疗图像计算和计算机辅助干预措施(MICCAI)2015年的挑战,其中有三位经验丰富的观察者注释了地标,以获得其平均位置。在24个鉴于我们具有地面真相的序列的24个序列上,所有地标的平均跟踪误差为0.65 +/- 0.56毫米,所有地标的误差均在2 mm之内。我们进一步测试了从测试数据集中的69个地标上提出的模型,该模型具有与训练模式相似的图像模式,从而导致平均跟踪误差为0.94 +/- 0.83 mm。我们的实验结果表明,我们提出的方法使用US图像跟踪肝解剖学地标的可行性和准确性,为放射治疗期间的主动运动管理提供了潜在的解决方案。
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在神经元网络中,使用本地信息单独更新,允许完全分散的学习。相反,人工神经网络(ANN)中的元件通常使用中央处理器同时更新。在这里,我们调查最近引入的分散,物理驱动的学习网络中异步学习的可行性和影响。我们表明,在理想化模拟中,Desynchization Learing Processe不会降低各种任务的性能。在实验中,Des同步实际上通过允许系统更好地探索解决方案的离散状态空间来实现性能。我们在随机梯度下降中的异步和迷你批处理之间绘制了类比,并表明它们对学习过程具有类似的影响。 des同步学习过程将物理驱动的学习网络建立为真正完全分布式的学习机器,在部署中提高更好的性能和可扩展性。
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自由呼吸的心脏MRI计划是呼吸持有的Cine MRI协议的竞争替代方案,使适用于儿科和其他不能屏住呼吸的人群。因为来自切片的数据顺序获取,所以心脏/呼吸运动模式可能对每个切片不同;目前的自由呼吸方法对每个切片进行独立恢复。除了不能利用切片间冗余之外,需要手动干预或复杂的后处理方法来对准恢复后的图像进行量化。为了克服这些挑战,我们提出了一种无监督的变分深歧管学习方案,用于多层动态MRI的联合对准和重建。该方案共同了解深网络的参数以及捕获特定对象的K-T空间数据的运动引起的动态变化的每个切片的潜在矢量。变形框架最小化表示中的非唯一性,从而提供改进的对准和重建。
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Biological systems and processes are networks of complex nonlinear regulatory interactions between nucleic acids, proteins, and metabolites. A natural way in which to represent these interaction networks is through the use of a graph. In this formulation, each node represents a nucleic acid, protein, or metabolite and edges represent intermolecular interactions (inhibition, regulation, promotion, coexpression, etc.). In this work, a novel algorithm for the discovery of latent graph structures given experimental data is presented.
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This paper presents a machine learning approach to multidimensional item response theory (MIRT), a class of latent factor models that can be used to model and predict student performance from observed assessment data. Inspired by collaborative filtering, we define a general class of models that includes many MIRT models. We discuss the use of penalized joint maximum likelihood (JML) to estimate individual models and cross-validation to select the best performing model. This model evaluation process can be optimized using batching techniques, such that even sparse large-scale data can be analyzed efficiently. We illustrate our approach with simulated and real data, including an example from a massive open online course (MOOC). The high-dimensional model fit to this large and sparse dataset does not lend itself well to traditional methods of factor interpretation. By analogy to recommender-system applications, we propose an alternative "validation" of the factor model, using auxiliary information about the popularity of items consulted during an open-book exam in the course.
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Real-world robotic grasping can be done robustly if a complete 3D Point Cloud Data (PCD) of an object is available. However, in practice, PCDs are often incomplete when objects are viewed from few and sparse viewpoints before the grasping action, leading to the generation of wrong or inaccurate grasp poses. We propose a novel grasping strategy, named 3DSGrasp, that predicts the missing geometry from the partial PCD to produce reliable grasp poses. Our proposed PCD completion network is a Transformer-based encoder-decoder network with an Offset-Attention layer. Our network is inherently invariant to the object pose and point's permutation, which generates PCDs that are geometrically consistent and completed properly. Experiments on a wide range of partial PCD show that 3DSGrasp outperforms the best state-of-the-art method on PCD completion tasks and largely improves the grasping success rate in real-world scenarios. The code and dataset will be made available upon acceptance.
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Optical coherence tomography (OCT) captures cross-sectional data and is used for the screening, monitoring, and treatment planning of retinal diseases. Technological developments to increase the speed of acquisition often results in systems with a narrower spectral bandwidth, and hence a lower axial resolution. Traditionally, image-processing-based techniques have been utilized to reconstruct subsampled OCT data and more recently, deep-learning-based methods have been explored. In this study, we simulate reduced axial scan (A-scan) resolution by Gaussian windowing in the spectral domain and investigate the use of a learning-based approach for image feature reconstruction. In anticipation of the reduced resolution that accompanies wide-field OCT systems, we build upon super-resolution techniques to explore methods to better aid clinicians in their decision-making to improve patient outcomes, by reconstructing lost features using a pixel-to-pixel approach with an altered super-resolution generative adversarial network (SRGAN) architecture.
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The Government of Kerala had increased the frequency of supply of free food kits owing to the pandemic, however, these items were static and not indicative of the personal preferences of the consumers. This paper conducts a comparative analysis of various clustering techniques on a scaled-down version of a real-world dataset obtained through a conjoint analysis-based survey. Clustering carried out by centroid-based methods such as k means is analyzed and the results are plotted along with SVD, and finally, a conclusion is reached as to which among the two is better. Once the clusters have been formulated, commodities are also decided upon for each cluster. Also, clustering is further enhanced by reassignment, based on a specific cluster loss threshold. Thus, the most efficacious clustering technique for designing a food kit tailored to the needs of individuals is finally obtained.
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Using Structural Health Monitoring (SHM) systems with extensive sensing arrangements on every civil structure can be costly and impractical. Various concepts have been introduced to alleviate such difficulties, such as Population-based SHM (PBSHM). Nevertheless, the studies presented in the literature do not adequately address the challenge of accessing the information on different structural states (conditions) of dissimilar civil structures. The study herein introduces a novel framework named Structural State Translation (SST), which aims to estimate the response data of different civil structures based on the information obtained from a dissimilar structure. SST can be defined as Translating a state of one civil structure to another state after discovering and learning the domain-invariant representation in the source domains of a dissimilar civil structure. SST employs a Domain-Generalized Cycle-Generative (DGCG) model to learn the domain-invariant representation in the acceleration datasets obtained from a numeric bridge structure that is in two different structural conditions. In other words, the model is tested on three dissimilar numeric bridge models to translate their structural conditions. The evaluation results of SST via Mean Magnitude-Squared Coherence (MMSC) and modal identifiers showed that the translated bridge states (synthetic states) are significantly similar to the real ones. As such, the minimum and maximum average MMSC values of real and translated bridge states are 91.2% and 97.1%, the minimum and the maximum difference in natural frequencies are 5.71% and 0%, and the minimum and maximum Modal Assurance Criterion (MAC) values are 0.998 and 0.870. This study is critical for data scarcity and PBSHM, as it demonstrates that it is possible to obtain data from structures while the structure is actually in a different condition or state.
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Over the past decade, neural networks have been successful at making predictions from biological sequences, especially in the context of regulatory genomics. As in other fields of deep learning, tools have been devised to extract features such as sequence motifs that can explain the predictions made by a trained network. Here we intend to go beyond explainable machine learning and introduce SEISM, a selective inference procedure to test the association between these extracted features and the predicted phenotype. In particular, we discuss how training a one-layer convolutional network is formally equivalent to selecting motifs maximizing some association score. We adapt existing sampling-based selective inference procedures by quantizing this selection over an infinite set to a large but finite grid. Finally, we show that sampling under a specific choice of parameters is sufficient to characterize the composite null hypothesis typically used for selective inference-a result that goes well beyond our particular framework. We illustrate the behavior of our method in terms of calibration, power and speed and discuss its power/speed trade-off with a simpler data-split strategy. SEISM paves the way to an easier analysis of neural networks used in regulatory genomics, and to more powerful methods for genome wide association studies (GWAS).
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