大多数人工智能(AI)研究都集中在高收入国家,其中成像数据,IT基础设施和临床专业知识丰富。但是,在需要医学成像的有限资源环境中取得了较慢的进步。例如,在撒哈拉以南非洲,由于获得产前筛查的机会有限,围产期死亡率的率很高。在这些国家,可以实施AI模型,以帮助临床医生获得胎儿超声平面以诊断胎儿异常。到目前为止,已经提出了深度学习模型来识别标准的胎儿平面,但是没有证据表明它们能够概括获得高端超声设备和数据的中心。这项工作研究了不同的策略,以减少在高资源临床中心训练并转移到新的低资源中心的胎儿平面分类模型的域转移效果。为此,首先在丹麦的一个新中心对1,008例患者的新中心进行评估,接受了1,008名患者的新中心,后来对五个非洲中心(埃及,阿尔及利亚,乌干达,加纳和马拉维进行了相同的表现),首先在丹麦的一个新中心进行评估。 )每个患者有25名。结果表明,转移学习方法可以是将小型非洲样本与发达国家现有的大规模数据库相结合的解决方案。特别是,该模型可以通过将召回率提高到0.92 \ pm 0.04 $,同时又可以维持高精度。该框架显示了在临床中心构建可概括的新AI模型的希望,该模型在具有挑战性和异质条件下获得的数据有限,并呼吁进行进一步的研究,以开发用于资源较少的国家 /地区的AI可用性的新解决方案。
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The task of locating and classifying different types of vehicles has become a vital element in numerous applications of automation and intelligent systems ranging from traffic surveillance to vehicle identification and many more. In recent times, Deep Learning models have been dominating the field of vehicle detection. Yet, Bangladeshi vehicle detection has remained a relatively unexplored area. One of the main goals of vehicle detection is its real-time application, where `You Only Look Once' (YOLO) models have proven to be the most effective architecture. In this work, intending to find the best-suited YOLO architecture for fast and accurate vehicle detection from traffic images in Bangladesh, we have conducted a performance analysis of different variants of the YOLO-based architectures such as YOLOV3, YOLOV5s, and YOLOV5x. The models were trained on a dataset containing 7390 images belonging to 21 types of vehicles comprising samples from the DhakaAI dataset, the Poribohon-BD dataset, and our self-collected images. After thorough quantitative and qualitative analysis, we found the YOLOV5x variant to be the best-suited model, performing better than YOLOv3 and YOLOv5s models respectively by 7 & 4 percent in mAP, and 12 & 8.5 percent in terms of Accuracy.
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The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.
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In this paper, deep-learning-based approaches namely fine-tuning of pretrained convolutional neural networks (VGG16 and VGG19), and end-to-end training of a developed CNN model, have been used in order to classify X-Ray images into four different classes that include COVID-19, normal, opacity and pneumonia cases. A dataset containing more than 20,000 X-ray scans was retrieved from Kaggle and used in this experiment. A two-stage classification approach was implemented to be compared to the one-shot classification approach. Our hypothesis was that a two-stage model will be able to achieve better performance than a one-shot model. Our results show otherwise as VGG16 achieved 95% accuracy using one-shot approach over 5-fold of training. Future work will focus on a more robust implementation of the two-stage classification model Covid-TSC. The main improvement will be allowing data to flow from the output of stage-1 to the input of stage-2, where stage-1 and stage-2 models are VGG16 models fine-tuned on the Covid-19 dataset.
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种植植被是降低沉积物转移率的实用解决方案之一。植被覆盖的增加可降低环境污染和沉积物的运输速率(STR)。由于沉积物和植被相互作用复杂,因此预测沉积物的运输速率具有挑战性。这项研究旨在使用新的和优化的数据处理方法(GMDH)的新版本(GMDH)预测植被覆盖的沉积物传输速率。此外,这项研究介绍了一种用于预测沉积物传输速率的新集合模型。模型输入包括波高,波速,密度覆盖,波力,D50,植被盖的高度和盖茎直径。独立的GMDH模型和优化的GMDH模型,包括GMDH Honey Badger算法(HBA)GMDH大鼠群群算法(RSOA)VGMDH正弦余弦算法(SCA)和GMDH颗粒swarm swarm优化率(GMDH-PSO),用于预测沉积率(GMDH-PSO) 。作为下一步,使用独立的GMDH的输出来构建集合模型。合奏模型的MAE为0.145 m3/s,而GMDH-HBA,GMDH-RSOA,GMDH-SCA,GMDH-PSOA和GMDH的MAE在测试水平为0.176 M3/s,0.312 M3/s,0.367/s,0.367 M3/s,0.498 m3/s和0.612 m3/s。集合模型的Nash Sutcliffe系数(NSE),GMDH-HBA,GMDH-RSOA,GMDH-SCA,GMDH-PSOA和GHMDH分别为0.95 0.93、0.89、0.89、0.86、0.86、0.82和0.76。此外,这项研究表明,植被覆盖的沉积物运输速率降低了90%。结果表明,合奏和GMDH-HBA模型可以准确预测沉积物的传输速率。根据这项研究的结果,可以使用IMM和GMDH-HBA监测沉积物的传输速率。这些结果对于管理和规划大盆地的水资源很有用。
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在本文中,我们分析了具有基于视觉导航的无人机(UAV)的时间延迟动力学对控制器设计的影响。时间延迟是网络物理系统中不可避免的现象,并且对无人机的控制器设计和轨迹产生具有重要意义。时间延迟对无人机动态的影响随着基于视力较慢的导航堆栈的使用而增加。我们表明,文献中的现有模型不包括时间延迟,不适合控制器调整,因为一个微不足道的解决方案始终存在错误的解决方案。我们确定的微不足道的解决方案表明,使用无限控制器的利益来实现最佳性能,这与实际发现相矛盾。我们通过引入无人机的新型非线性时间延迟模型来避免这种缺点,然后获得与每个UAV控制回路相对应的一组线性解耦模型。分析了角度和高度动力学的线性时间延迟模型的成本函数,与无延迟模型相反,我们显示了有限的最佳控制器参数的存在。由于使用了时间延迟模型,我们在实验上表明,所提出的模型准确地表示系统稳定性限制。由于时间延迟的考虑,我们使用基于视觉探视的无人机(VO)导航,在跟踪峰值速度为2.09 m/s的lemsistate轨迹时,我们实现了RMSE 5.01 cm的跟踪结果,这与最新-艺术。
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这项研究是有关阿拉伯历史文档的光学特征识别(OCR)的一系列研究的第二阶段,并研究了不同的建模程序如何与问题相互作用。第一项研究研究了变压器对我们定制的阿拉伯数据集的影响。首次研究的弊端之一是训练数据的规模,由于缺乏资源,我们的3000万张图像中仅15000张图像。另外,我们添加了一个图像增强层,时间和空间优化和后校正层,以帮助该模型预测正确的上下文。值得注意的是,我们提出了一种使用视觉变压器作为编码器的端到端文本识别方法,即BEIT和Vanilla Transformer作为解码器,消除了CNNs以进行特征提取并降低模型的复杂性。实验表明,我们的端到端模型优于卷积骨架。该模型的CER为4.46%。
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联邦学习(FL)引起了人们对在存储在多个用户中的数据中启用隐私的机器学习的兴趣,同时避免将数据移动到偏离设备上。但是,尽管数据永远不会留下用户的设备,但仍然无法保证隐私,因为用户培训数据的重大计算以训练有素的本地模型的形式共享。最近,这些本地模型通过不同的隐私攻击(例如模型反演攻击)构成了实质性的隐私威胁。作为一种补救措施,通过保证服务器只能学习全局聚合模型更新,而不是单个模型更新,从而开发了安全汇总(SA)作为保护佛罗里达隐私的框架。尽管SA确保没有泄漏有关单个模型更新超出汇总模型更新的其他信息,但对于SA实际上可以提供多少私密性fl,没有正式的保证;由于有关单个数据集的信息仍然可以通过在服务器上计算的汇总模型泄漏。在这项工作中,我们对使用SA的FL的正式隐私保证进行了首次分析。具体而言,我们使用共同信息(MI)作为定量度量,并在每个用户数据集的信息上可以通过汇总的模型更新泄漏有关多少信息。当使用FEDSGD聚合算法时,我们的理论界限表明,隐私泄漏量随着SA参与FL的用户数量而线性减少。为了验证我们的理论界限,我们使用MI神经估计量来凭经验评估MNIST和CIFAR10数据集的不同FL设置下的隐私泄漏。我们的实验验证了FEDSGD的理论界限,随着用户数量和本地批量的增长,隐私泄漏的减少,并且随着培训回合的数量,隐私泄漏的增加。
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由于其在非洲以外的40多个国家 /地区的迅速传播,最近的蒙基托克斯爆发已成为公共卫生问题。由于与水痘和麻疹的相似之处,蒙基托斯在早期的临床诊断是具有挑战性的。如果不容易获得验证性聚合酶链反应(PCR)测试,那么计算机辅助检测蒙基氧基病变可能对可疑病例的监视和快速鉴定有益。只要有足够的训练示例,深度学习方法在自动检测皮肤病变中有效。但是,截至目前,此类数据集尚未用于猴蛋白酶疾病。在当前的研究中,我们首先开发``Monkeypox皮肤病变数据集(MSLD)。用于增加样本量,并建立了3倍的交叉验证实验。在下一步中,采用了几种预训练的深度学习模型,即VGG-16,Resnet50和InceptionV3用于对Monkeypox和Monkeypox和Monkeypox和其他疾病。还开发了三种型号的合奏。RESNET50达到了82.96美元(\ pm4.57 \%)$的最佳总体准确性,而VGG16和整体系统的准确性达到了81.48美元(\ pm6.87 \%)$和$ 79.26(\ pm1.05 \%)$。还开发了一个原型网络应用程序作为在线蒙基蛋白筛选工具。虽然该有限数据集的初始结果是有希望的,但需要更大的人口统计学多样化的数据集来进一步增强性增强性。这些的普遍性 楷模。
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肿瘤浸润淋巴细胞(TIL)的定量已被证明是乳腺癌患者预后的独立预测因子。通常,病理学家对含有tils的基质区域的比例进行估计,以获得TILS评分。乳腺癌(Tiger)挑战中肿瘤浸润淋巴细胞旨在评估计算机生成的TILS评分的预后意义,以预测作为COX比例风险模型的一部分的存活率。在这一挑战中,作为Tiager团队,我们已经开发了一种算法,以将肿瘤与基质与基质进行第一部分,然后将肿瘤散装区域用于TILS检测。最后,我们使用这些输出来生成每种情况的TILS分数。在初步测试中,我们的方法达到了肿瘤 - 细胞瘤的加权骰子评分为0.791,而淋巴细胞检测的FROC得分为0.572。为了预测生存,我们的模型达到了0.719的C索引。这些结果在老虎挑战的初步测试排行榜中获得了第一名。
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