cross-entropy

交叉熵
  • 文章类型: Journal Article
    非欧几里得数据,例如社交网络和文档之间的引用关系,具有节点和结构信息。图卷积网络(GCN)可以自动学习节点特征和节点之间的关联信息。图卷积网络的核心思想是利用边缘信息聚合节点信息,从而生成新的节点特征。在更新节点特征时,有两个核心影响因素。一个是中心节点的相邻节点的数量;另一个是相邻节点对中心节点的贡献。由于以前的GCN方法没有同时考虑相邻节点对中心节点的数量和不同贡献,我们设计了自适应注意力机制(AAM)。为了进一步增强模型的表示能力,我们利用多头图卷积(MHGC)。最后,我们采用交叉熵(CE)损失函数来描述节点类别的预测结果与地面实况(GT)之间的差异。结合反向传播,这最终实现了节点的准确分类。基于AAM,MHGC,CE,我们设计了新颖的图形自适应注意力网络(GAAN)。实验表明,分类精度在Cora上取得了突出的性能,Citeseer,和发布的数据集。
    Non-Euclidean data, such as social networks and citation relationships between documents, have node and structural information. The Graph Convolutional Network (GCN) can automatically learn node features and association information between nodes. The core ideology of the Graph Convolutional Network is to aggregate node information by using edge information, thereby generating a new node feature. In updating node features, there are two core influencing factors. One is the number of neighboring nodes of the central node; the other is the contribution of the neighboring nodes to the central node. Due to the previous GCN methods not simultaneously considering the numbers and different contributions of neighboring nodes to the central node, we design the adaptive attention mechanism (AAM). To further enhance the representational capability of the model, we utilize Multi-Head Graph Convolution (MHGC). Finally, we adopt the cross-entropy (CE) loss function to describe the difference between the predicted results of node categories and the ground truth (GT). Combined with backpropagation, this ultimately achieves accurate node classification. Based on the AAM, MHGC, and CE, we contrive the novel Graph Adaptive Attention Network (GAAN). The experiments show that classification accuracy achieves outstanding performances on Cora, Citeseer, and Pubmed datasets.
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  • 文章类型: Journal Article
    现有的基于分割的场景文本检测方法大多需要复杂的后处理,后处理操作与培训过程分离,这大大降低了检测性能。以前的方法,DBNet,成功地简化了后处理,并将后处理集成到分割网络中。然而,模型的训练过程历时1200个时期,缺乏对各种尺度文本的敏感性,导致一些文本实例被错过。考虑到以上两个问题,设计了双曲正切二值化文本检测网络(HTBNet)。首先,我们提出了双曲正切(HTB)的二值化,通过优化,分割网络可以通过将纪元的数量从1200减少到600来加快初始收敛速度。由于同一尺度特征图中不同通道的特征集中于图像中不同区域的信息,为了更好地表示图像中所有对象的重要特征,我们设计了多尺度频道注意力(MSCA)。同时,考虑到图像中的多尺度对象不能同时检测,我们提出了一个新的模块,名为带通道和空间的融合模块(FMCS),可以融合通道和空间维度的多尺度特征图。最后,我们采用交叉熵作为损失函数,衡量预测值和地面真理之间的差异。实验结果表明,HTBNet,与轻质型号相比,在Total-Text(F-measure:86.0%,FPS:30)和MSRA-TD500(F测量:87.5%,FPS:30).
    The existing segmentation-based scene text detection methods mostly need complicated post-processing, and the post-processing operation is separated from the training process, which greatly reduces the detection performance. The previous method, DBNet, successfully simplified post-processing and integrated post-processing into a segmentation network. However, the training process of the model took a long time for 1200 epochs and the sensitivity to texts of various scales was lacking, leading to some text instances being missed. Considering the above two problems, we design the text detection Network with Binarization of Hyperbolic Tangent (HTBNet). First of all, we propose the Binarization of Hyperbolic Tangent (HTB), optimized along with which the segmentation network can expedite the initial convergent speed by reducing the number of epochs from 1200 to 600. Because features of different channels in the same scale feature map focus on the information of different regions in the image, to better represent the important features of all objects in the image, we devise the Multi-Scale Channel Attention (MSCA). Meanwhile, considering that multi-scale objects in the image cannot be simultaneously detected, we propose a novel module named Fused Module with Channel and Spatial (FMCS), which can fuse the multi-scale feature maps from channel and spatial dimensions. Finally, we adopt cross-entropy as the loss function, which measures the difference between predicted values and ground truths. The experimental results show that HTBNet, compared with lightweight models, has achieved competitive performance and speed on Total-Text (F-measure:86.0%, FPS:30) and MSRA-TD500 (F-measure:87.5%, FPS:30).
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  • 文章类型: Journal Article
    背景:MRI图像上的膀胱癌(BC)分割是确定是否存在肌肉浸润的第一步。本研究旨在评估三种深度学习(DL)模型在多参数MRI(mp-MRI)图像上的肿瘤分割性能。
    方法:我们研究了53例膀胱癌患者。膀胱肿瘤在T2加权(T2WI)的每个切片上进行分割,扩散加权成像/表观扩散系数(DWI/ADC),和在3TeslaMRI扫描仪上采集的T1加权对比增强(T1WI)图像。我们训练了Unet,MAnet,和PSPnet使用三个损失函数:交叉熵(CE),骰子相似系数损失(DSC),和病灶丢失(FL)。我们使用DSC评估了模型性能,Hausdorff距离(HD),和预期校准误差(ECE)。
    结果:具有CE+DSC损失函数的MAnet算法在ADC上给出了最高的DSC值,T2WI,和T1WI图像。PSPnet与CE+DSC在ADC上获得了最小的HDs,T2WI,和T1WI图像。总体上,ADC和T1WI的分割精度优于T2WI。在ADC图像上,带FL的PSPnet的ECE最小,而在T2WI和T1WI上使用CE+DSC的MAnet是最小的。
    结论:与Unet相比,根据评估指标的选择,具有混合CEDSC损失函数的MAnet和PSPnet在BC分割中显示出更好的性能。
    BACKGROUND: Bladder cancer (BC) segmentation on MRI images is the first step to determining the presence of muscular invasion. This study aimed to assess the tumor segmentation performance of three deep learning (DL) models on multi-parametric MRI (mp-MRI) images.
    METHODS: We studied 53 patients with bladder cancer. Bladder tumors were segmented on each slice of T2-weighted (T2WI), diffusion-weighted imaging/apparent diffusion coefficient (DWI/ADC), and T1-weighted contrast-enhanced (T1WI) images acquired at a 3Tesla MRI scanner. We trained Unet, MAnet, and PSPnet using three loss functions: cross-entropy (CE), dice similarity coefficient loss (DSC), and focal loss (FL). We evaluated the model performances using DSC, Hausdorff distance (HD), and expected calibration error (ECE).
    RESULTS: The MAnet algorithm with the CE+DSC loss function gave the highest DSC values on the ADC, T2WI, and T1WI images. PSPnet with CE+DSC obtained the smallest HDs on the ADC, T2WI, and T1WI images. The segmentation accuracy overall was better on the ADC and T1WI than on the T2WI. The ECEs were the smallest for PSPnet with FL on the ADC images, while they were the smallest for MAnet with CE+DSC on the T2WI and T1WI.
    CONCLUSIONS: Compared to Unet, MAnet and PSPnet with a hybrid CE+DSC loss function displayed better performances in BC segmentation depending on the choice of the evaluation metric.
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  • 文章类型: Journal Article
    交叉熵损失在训练许多深度神经网络中至关重要。在这种情况下,我们在各种相关的发散函数之间显示了许多新颖而强烈的相关性。特别是,我们证明,在某些情况下,(a)交叉熵与鲜为人知的三角发散几乎完全相关,并且(b)交叉熵与从其导出softmax的对数上的欧几里德距离密切相关。这些观察的结果如下。首先,三角散度可以用作交叉熵的更便宜的替代方案。第二,logit可以用作欧几里得空间中的特征,该特征与分类过程具有很强的协同作用。这证明了使用欧几里得距离超过日志作为相似性度量的合理性,在使用softmax和交叉熵训练网络的情况下。我们通过经验观察来建立这些相关性,由包含许多强相关的发散函数的数学解释支持。
    Cross-entropy loss is crucial in training many deep neural networks. In this context, we show a number of novel and strong correlations among various related divergence functions. In particular, we demonstrate that, in some circumstances, (a) cross-entropy is almost perfectly correlated with the little-known triangular divergence, and (b) cross-entropy is strongly correlated with the Euclidean distance over the logits from which the softmax is derived. The consequences of these observations are as follows. First, triangular divergence may be used as a cheaper alternative to cross-entropy. Second, logits can be used as features in a Euclidean space which is strongly synergistic with the classification process. This justifies the use of Euclidean distance over logits as a measure of similarity, in cases where the network is trained using softmax and cross-entropy. We establish these correlations via empirical observation, supported by a mathematical explanation encompassing a number of strongly related divergence functions.
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  • 文章类型: Journal Article
    该研究的目的是提出一种使用专用于微阵列数据集的区间建模的多类集成分类器。使用了为组成分类器的单个预测值创建不确定性区间,然后使用区间值聚合函数聚合获得的区间的方法。提出的异构分类采用随机森林,支持向量机,和多层感知器作为分量分类器,利用交叉熵选择最优分类器。此外,应用间隔的顺序来确定对象的决策类。根据优化所考虑的集成分类器的性能来测试所应用的区间值聚合函数。所提出的模型的质量,优于其他知名和组件分类器,通过比较验证,证明了交叉熵在集成模型构建中的有效性。
    The purpose of the study is to propose a multi-class ensemble classifier using interval modeling dedicated to microarray datasets. An approach of creating the uncertainty intervals for the single prediction values of constituent classifiers and then aggregating the obtained intervals with the use of interval-valued aggregation functions is used. The proposed heterogeneous classification employs Random Forest, Support Vector Machines, and Multilayer Perceptron as component classifiers, utilizing cross-entropy to select the optimal classifier. Moreover, orders for intervals are applied to determine the decision class of an object. The applied interval-valued aggregation functions are tested in terms of optimizing the performance of the considered ensemble classifier. The proposed model\'s quality, superior to other well-known and component classifiers, is validated through comparison, demonstrating the efficacy of cross-entropy in ensemble model construction.
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  • 文章类型: Journal Article
    钢表面通常显示出复杂的纹理图案,可能类似于缺陷,在准确识别实际缺陷方面构成了挑战。因此,建立一个高鲁棒性的缺陷检测模型至关重要。提出了一种基于正则化YOLO框架的钢材红外图像缺陷检测方法。首先,协调注意力(CA)嵌入在C2F框架中,利用轻量级的注意模块来增强骨干网络的特征提取能力。其次,颈部部分设计结合了双向特征金字塔网络(BiFPN),用于多尺度特征图的加权融合。这将创建一个名为BiFPN-Concat的模型,这增强了特征融合能力。最后,模型的损失函数进行正则化,提高模型的泛化性能。实验结果表明,该模型参数只有3.03M,然而,在NEU-DET数据集上达到80.77%的mAP@0.5,在ECTI数据集上达到99.38%。这表示比基准模型提高了2.3%和1.6%,分别。此方法非常适合使用红外图像对钢铁进行无损检测的工业检测应用。
    Steel surfaces often display intricate texture patterns that can resemble defects, posing a challenge in accurately identifying actual defects. Therefore, it is crucial to develop a highly robust defect detection model. This study proposes a defect detection method for steel infrared images based on a Regularized YOLO framework. Firstly, the Coordinate Attention (CA) is embedded within the C2F framework, utilizing a lightweight attention module to enhance the feature extraction capability of the backbone network. Secondly, the neck part design incorporates the Bi-directional Feature Pyramid Network (BiFPN) for weighted fusion of multi-scale feature maps. This creates a model called BiFPN-Concat, which enhances feature fusion capability. Finally, the loss function of the model is regularized to improve the generalization performance of the model. The experimental results indicate that the model has only 3.03 M parameters, yet achieves a mAP@0.5 of 80.77% on the NEU-DET dataset and 99.38% on the ECTI dataset. This represents an improvement of 2.3% and 1.6% over the baseline model, respectively. This method is well-suited for industrial detection applications involving non-destructive testing of steel using infrared imagery.
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  • 文章类型: Journal Article
    纵向和时间到事件数据的联合模型通常用于计算在精确医学的许多应用中使用的动态个性化预测。影响这些预测准确性的关节模型的两个组成部分是纵向轨迹的形状和将纵向结果历史与事件危险联系起来的功能形式。找到一个明确的模型,为所有受试者和后续时间产生准确的预测可能是具有挑战性的,特别是在考虑多个纵向结果时。在这项工作中,我们使用超级学习的概念,避免选择单一的模型。特别是,我们指定从具有不同规格的关节模型库计算的动态预测的加权组合。选择权重以使用V折交叉验证来优化预测准确性度量。我们使用预期的二次预测误差和预期的预测交叉熵作为预测准确性度量。在模拟研究中,我们发现超级学习方法产生的结果与Oracle模型非常相似,这是测试数据集中性能最好的模型。所有提出的方法都在免费提供的R包JMbayes2中实现。
    Joint models for longitudinal and time-to-event data are often employed to calculate dynamic individualized predictions used in numerous applications of precision medicine. Two components of joint models that influence the accuracy of these predictions are the shape of the longitudinal trajectories and the functional form linking the longitudinal outcome history to the hazard of the event. Finding a single well-specified model that produces accurate predictions for all subjects and follow-up times can be challenging, especially when considering multiple longitudinal outcomes. In this work, we use the concept of super learning and avoid selecting a single model. In particular, we specify a weighted combination of the dynamic predictions calculated from a library of joint models with different specifications. The weights are selected to optimize a predictive accuracy metric using V-fold cross-validation. We use as predictive accuracy measures the expected quadratic prediction error and the expected predictive cross-entropy. In a simulation study, we found that the super learning approach produces results very similar to the Oracle model, which was the model with the best performance in the test datasets. All proposed methodology is implemented in the freely available R package JMbayes2.
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  • 文章类型: Journal Article
    问题匹配是基于检索的对话系统中的基本任务,该系统评估查询与问题之间的相似性。不幸的是,现有的方法侧重于提高一般领域中文本相似度的准确性,不适应金融领域。财务问题匹配有两个关键问题:(1)如何准确地对财务句子的上下文表示进行建模?(2)如何在话语中准确地表示财务关键短语?为了解决这些问题,本文提出了一种新颖的金融知识增强网络(FinKENet),该网络将金融知识显着地注入到上下文文本中。具体来说,我们提出了一个多级编码器来提取句子级特征和金融短语级特征,可以更准确地表示句子和财务短语。此外,我们提出了一种金融共同关注适配器,以结合句子特征和金融关键词特征。最后,我们设计了一个多级相似度解码器来计算查询和问题之间的相似度。此外,提出了一种基于交叉熵的损失函数,用于模型优化。实验结果证明了该方法在蚂蚁金服问题匹配数据集上的有效性。特别是,Recall评分从73.21%提高到74.90%(绝对1.69%)。
    Question matching is the fundamental task in retrieval-based dialogue systems which assesses the similarity between Query and Question. Unfortunately, existing methods focus on improving the accuracy of text similarity in the general domain, without adaptation to the financial domain. Financial question matching has two critical issues: (1) How to accurately model the contextual representation of a financial sentence? (2) How to accurately represent financial key phrases in an utterance? To address these issues, this paper proposes a novel Financial Knowledge Enhanced Network (FinKENet) that significantly injects financial knowledge into contextual text. Specifically, we propose a multi-level encoder to extract both sentence-level features and financial phrase-level features, which can more accurately represent sentences and financial phrases. Furthermore, we propose a financial co-attention adapter to combine sentence features and financial keyword features. Finally, we design a multi-level similarity decoder to calculate the similarity between queries and questions. In addition, a cross-entropy-based loss function is presented for model optimization. Experimental results demonstrate the effectiveness of the proposed method on the Ant Financial question matching dataset. In particular, the Recall score improves from 73.21% to 74.90% (1.69% absolute).
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  • 文章类型: Journal Article
    在许多国家,管理渔业的可持续性目标通常以承载能力的固定百分比表示。尽管这样一个简单的量化目标很有吸引力,一个意想不到的后果可能是不同年龄的生物量比例显著倾斜,从他们在无收获条件下的情况来看。在广泛使用的年龄结构模型的框架内,我们提出了“年龄平衡收获”的新定量定义,该定义考虑了相对于未捕捞种群的年龄组组成。我们表明,如果我们收获任何鱼类,就不可能实现完美的年龄平衡政策。然而,每一个重要的收获政策都有一个有利于年轻人的特殊结构。为了量化年龄失衡的程度,我们提出了一个交叉熵函数。我们提出了一个优化问题,旨在达到“年龄平衡的稳态”,要有足够的产量。我们证明,通过牺牲少量产量,可以实现近乎平衡的收获政策。这些发现通过提供有关权衡和收获政策建议的见解,对可持续渔业管理具有重要意义。
    In many countries, sustainability targets for managed fisheries are often expressed in terms of a fixed percentage of the carrying capacity. Despite the appeal of such a simple quantitative target, an unintended consequence may be a significant tilting of the proportions of biomass across different ages, from what they would have been under harvest-free conditions. Within the framework of a widely used age-structured model, we propose a novel quantitative definition of \"age-balanced harvest\" that considers the age-class composition relative to that of the unfished population. We show that achieving a perfectly age-balanced policy is impossible if we harvest any fish whatsoever. However, every non-trivial harvest policy has a special structure that favours the young. To quantify the degree of age-imbalance, we propose a cross-entropy function. We formulate an optimisation problem that aims to attain an \"age-balanced steady state\", subject to adequate yield. We demonstrate that near balanced harvest policies are achievable by sacrificing a small amount of yield. These findings have important implications for sustainable fisheries management by providing insights into trade-offs and harvest policy recommendations.
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  • 文章类型: Journal Article
    深度神经网络在遥感影像分析中取得了巨大的成就,以前的研究表明,深度神经网络表现出令人难以置信的脆弱性对抗性的例子,这引起了人们对区域安全和生产安全的担忧。在本文中,提出了一种基于潜在表示指导的对抗式去噪方法,用于遥感图像场景分类。在训练阶段,我们训练一个变分自动编码器来只使用干净的数据集重建数据。在测试时间,我们首先使用变分自动编码器计算重建图像与参考图像之间的归一化互信息,并通过离散余弦变换进行去噪。根据图像质量评估的结果选择性地利用重建的图像。然后,根据重建损失迭代更新当前图像的潜在表示,以逐步消除对抗噪声的影响。因为去噪器的训练只涉及干净的数据,该方法对未知对抗噪声具有更强的鲁棒性。在场景分类数据集上的实验结果表明了该方法的有效性。此外,在图像分类任务中,与最先进的对抗防御方法相比,该方法具有更好的鲁棒性。
    Deep neural networks have made great achievements in remote sensing image analyses; however, previous studies have shown that deep neural networks exhibit incredible vulnerability to adversarial examples, which raises concerns about regional safety and production safety. In this paper, we propose an adversarial denoising method based on latent representation guidance for remote sensing image scene classification. In the training phase, we train a variational autoencoder to reconstruct the data using only the clean dataset. At test time, we first calculate the normalized mutual information between the reconstructed image using the variational autoencoder and the reference image as denoised by a discrete cosine transform. The reconstructed image is selectively utilized according to the result of the image quality assessment. Then, the latent representation of the current image is iteratively updated according to the reconstruction loss so as to gradually eliminate the influence of adversarial noise. Because the training of the denoiser only involves clean data, the proposed method is more robust against unknown adversarial noise. Experimental results on the scene classification dataset show the effectiveness of the proposed method. Furthermore, the method achieves better robust accuracy compared with state-of-the-art adversarial defense methods in image classification tasks.
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