XAI

XAI
  • 文章类型: Journal Article
    尽管现有几种使用标准单模光纤(SMF)进行分布式传感(温度和应变)的技术,补偿或解耦这两种效应对于许多应用是强制性的。目前,大多数去耦技术需要特殊的光纤,并且很难使用高空间分辨率的分布式技术来实现,例如OFDR。因此,这项工作的目的是研究解耦温度和应变的读出的相位和偏振分析仪OFDR(Φ-PA-OFDR)的SMF采取的可行性。为此,读数将使用几种机器学习算法进行研究,其中包括深度神经网络。这一目标背后的动机是当前在应变和温度变化的情况下广泛使用光纤传感器的障碍,由于当前开发的传感方法的耦合依赖性。而不是使用其他类型的传感器或甚至其他询问方法,这项工作的目的是分析可用的信息,以开发一种能够同时提供应变和温度信息的传感方法。
    Despite several existing techniques for distributed sensing (temperature and strain) using standard Single-Mode optical Fiber (SMF), compensating or decoupling both effects is mandatory for many applications. Currently, most decoupling techniques require special optical fibers and are difficult to implement with high-spatial-resolution distributed techniques, such as OFDR. Therefore, this work\'s objective is to study the feasibility of decoupling temperature and strain out of the readouts of a phase and polarization analyzer OFDR (ϕ-PA-OFDR) taken over an SMF. For this purpose, the readouts will be subjected to a study using several machine learning algorithms, among them Deep Neural Networks. The motivation that underlies this target is the current blockage in the widespread use of Fiber Optic Sensors in situations where both strain and temperature change, due to the coupled dependence of currently developed sensing methods. Instead of using other types of sensors or even other interrogation methods, the objective of this work is to analyze the available information in order to develop a sensing method capable of providing information about strain and temperature simultaneously.
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  • 文章类型: Journal Article
    背景:深度学习在医学成像诊断或股票交易等分类任务中提供了巨大的优势,尤其是与人类水平的表现相比,并且可以是在社区参与研究(CEnR)中对不同级别进行分类的可行选择。CEnR是学术界和社区合作伙伴之间的合作方法,旨在开展与社区需求相关的研究,同时融合各种形式的专业知识。在深度学习和人工智能(AI)领域,训练多个模型以获得最高的验证准确性是常见的做法;然而,它可能会过度适应特定的数据集,而不能很好地推广到现实世界的人群,这会产生偏见和潜在危险的算法决策问题。因此,如果我们计划让人类决策自动化,有必要为这些强大的无法解释的模型创建技术和详尽的评估过程,以确保我们不会合并和盲目信任不良的AI模型来做出现实世界的决策。
    目的:我们的目的是进行一项评估研究,以了解我们从以前的研究中得出的最准确的基于变压器的模型是否可以模仿我们自己的分类谱来跟踪CEnR研究,以及使用校准的置信度分数是否有意义。
    方法:我们比较了3位领域专家的结果,他对来自我们大学机构审查委员会数据库的45项研究的样本进行了分类,与来自3个先前训练的基于变压器的模型的那些,以及调查校准后的置信度分数是否可以成为将AI用于复杂决策系统的支持角色的可行技术。
    结果:我们的研究结果表明,某些模型通过高置信度分数对其性能进行了高估,尽管没有达到最高的验证准确性。
    结论:未来的研究应该以更大的样本量进行,以更有效地推广结果。尽管我们的研究解决了深度学习模型中偏差和过度拟合的问题,有必要进一步探索方法,让领域专家更信任我们的模型。在确定我们的AI模型的能力水平时,使用校准的置信度分数可能是一种误导性指标。
    BACKGROUND: Deep learning offers great benefits in classification tasks such as medical imaging diagnostics or stock trading, especially when compared with human-level performances, and can be a viable option for classifying distinct levels within community-engaged research (CEnR). CEnR is a collaborative approach between academics and community partners with the aim of conducting research that is relevant to community needs while incorporating diverse forms of expertise. In the field of deep learning and artificial intelligence (AI), training multiple models to obtain the highest validation accuracy is common practice; however, it can overfit toward that specific data set and not generalize well to a real-world population, which creates issues of bias and potentially dangerous algorithmic decisions. Consequently, if we plan on automating human decision-making, there is a need for creating techniques and exhaustive evaluative processes for these powerful unexplainable models to ensure that we do not incorporate and blindly trust poor AI models to make real-world decisions.
    OBJECTIVE: We aimed to conduct an evaluation study to see whether our most accurate transformer-based models derived from previous studies could emulate our own classification spectrum for tracking CEnR studies as well as whether the use of calibrated confidence scores was meaningful.
    METHODS: We compared the results from 3 domain experts, who classified a sample of 45 studies derived from our university\'s institutional review board database, with those from 3 previously trained transformer-based models, as well as investigated whether calibrated confidence scores can be a viable technique for using AI in a support role for complex decision-making systems.
    RESULTS: Our findings reveal that certain models exhibit an overestimation of their performance through high confidence scores, despite not achieving the highest validation accuracy.
    CONCLUSIONS: Future studies should be conducted with larger sample sizes to generalize the results more effectively. Although our study addresses the concerns of bias and overfitting in deep learning models, there is a need to further explore methods that allow domain experts to trust our models more. The use of a calibrated confidence score can be a misleading metric when determining our AI model\'s level of competency.
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  • 文章类型: Journal Article
    背景:数字即时自适应干预(JITAI)可以减少年轻人的暴饮暴食事件(BDE:女性/男性每次饮用4/5以上饮料),但需要针对时间和内容进行优化。在BDE之前的几个小时内及时提供支持信息可以改善干预效果。
    目标:我们确定了开发机器学习模型以准确预测未来的可行性。也就是说,同一天,使用智能手机传感器数据的BDE前1至6小时。我们旨在确定周末和工作日与BDE相关的信息最丰富的电话传感器功能,分别,来确定解释预测模型性能的关键特征。
    方法:我们收集了75名具有危险饮酒行为的年轻人(21-25岁;平均值=22.4,SD=1.9)的电话传感器数据,他们报告了超过14周的饮酒行为。这项二级分析的参与者参加了一项临床试验。我们开发了测试不同算法的机器学习模型(例如,XGBoost,决策树)使用智能手机传感器数据(例如,加速度计,GPS)。我们测试了从饮酒开始的各种“预测距离”时间窗口(更接近:1小时;到远处:6小时)。我们还测试了各种分析时间窗口(即,要分析的数据量),饮酒前1至12小时,因为这决定了计算模型需要存储在手机上的数据量。可解释的AI(XAI)用于探索对BDE有贡献的信息最多的电话传感器功能之间的相互作用。
    结果:XGBoost模型在预测即将到来的当天BDE方面表现最好,周末准确率为95.0%,工作日准确率为94.3%(F1评分分别为0.95和0.94)。这个XGBoost模型需要12-和9-小时的电话传感器数据在3-和6-小时的预测距离从饮酒开始,在周末和工作日,分别,在预测当天的BDE之前。用于BDE预测的信息最多的电话传感器功能是时间(例如,一天中的时间)和GPS派生的,如回转半径(行程指标)。关键特征之间的交互(例如,一天的时间,GPS派生的功能)有助于当天BDE的预测。
    结论:我们证明了智能手机传感器数据和机器学习的可行性和潜在用途,可以准确预测年轻人中即将发生的(当天)BDE。预测模型提供了“机会窗口”,并采用了XAI,我们确定了“关键贡献特征”以在BDE发作之前触发JITAI,有可能降低年轻人患BDE的可能性。
    BACKGROUND: Digital just-in-time adaptive interventions can reduce binge-drinking events (BDEs; consuming ≥4 drinks for women and ≥5 drinks for men per occasion) in young adults but need to be optimized for timing and content. Delivering just-in-time support messages in the hours prior to BDEs could improve intervention impact.
    OBJECTIVE: We aimed to determine the feasibility of developing a machine learning (ML) model to accurately predict future, that is, same-day BDEs 1 to 6 hours prior BDEs, using smartphone sensor data and to identify the most informative phone sensor features associated with BDEs on weekends and weekdays to determine the key features that explain prediction model performance.
    METHODS: We collected phone sensor data from 75 young adults (aged 21 to 25 years; mean 22.4, SD 1.9 years) with risky drinking behavior who reported their drinking behavior over 14 weeks. The participants in this secondary analysis were enrolled in a clinical trial. We developed ML models testing different algorithms (eg, extreme gradient boosting [XGBoost] and decision tree) to predict same-day BDEs (vs low-risk drinking events and non-drinking periods) using smartphone sensor data (eg, accelerometer and GPS). We tested various \"prediction distance\" time windows (more proximal: 1 hour; distant: 6 hours) from drinking onset. We also tested various analysis time windows (ie, the amount of data to be analyzed), ranging from 1 to 12 hours prior to drinking onset, because this determines the amount of data that needs to be stored on the phone to compute the model. Explainable artificial intelligence was used to explore interactions among the most informative phone sensor features contributing to the prediction of BDEs.
    RESULTS: The XGBoost model performed the best in predicting imminent same-day BDEs, with 95% accuracy on weekends and 94.3% accuracy on weekdays (F1-score=0.95 and 0.94, respectively). This XGBoost model needed 12 and 9 hours of phone sensor data at 3- and 6-hour prediction distance from the onset of drinking on weekends and weekdays, respectively, prior to predicting same-day BDEs. The most informative phone sensor features for BDE prediction were time (eg, time of day) and GPS-derived features, such as the radius of gyration (an indicator of travel). Interactions among key features (eg, time of day and GPS-derived features) contributed to the prediction of same-day BDEs.
    CONCLUSIONS: We demonstrated the feasibility and potential use of smartphone sensor data and ML for accurately predicting imminent (same-day) BDEs in young adults. The prediction model provides \"windows of opportunity,\" and with the adoption of explainable artificial intelligence, we identified \"key contributing features\" to trigger just-in-time adaptive intervention prior to the onset of BDEs, which has the potential to reduce the likelihood of BDEs in young adults.
    BACKGROUND: ClinicalTrials.gov NCT02918565; https://clinicaltrials.gov/ct2/show/NCT02918565.
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  • 文章类型: Journal Article
    识别面部表情一直是科学界的目标。自从人工智能兴起以来,卷积神经网络(CNN)已经成为识别面部表情的流行,作为图像可以直接用作输入。当前的CNN模型可以实现高识别率,但是他们不知道他们的推理过程。可解释人工智能(XAI)已被开发为一种帮助解释机器学习模型获得的结果的手段。处理图像时,最常用的XAI技术之一是LIME。LIME突出显示图像中有助于分类的区域。作为LIME的替代品,CEM方法出现了,以自然的方式提供对人类分类的解释:除了强调什么足以证明分类是合理的,它还确定了维护它应该缺少什么,并将其与另一种分类区分开来。这项研究提供了将LIME和CEM应用于复杂图像(例如面部表情图像)的比较结果。虽然CEM可以用来解释图像描述的结果,减少了数量的特征,当处理具有大量特征的图像时,LIME将是选择的方法。
    Recognizing facial expressions has been a persistent goal in the scientific community. Since the rise of artificial intelligence, convolutional neural networks (CNN) have become popular to recognize facial expressions, as images can be directly used as input. Current CNN models can achieve high recognition rates, but they give no clue about their reasoning process. Explainable artificial intelligence (XAI) has been developed as a means to help to interpret the results obtained by machine learning models. When dealing with images, one of the most-used XAI techniques is LIME. LIME highlights the areas of the image that contribute to a classification. As an alternative to LIME, the CEM method appeared, providing explanations in a way that is natural for human classification: besides highlighting what is sufficient to justify a classification, it also identifies what should be absent to maintain it and to distinguish it from another classification. This study presents the results of comparing LIME and CEM applied over complex images such as facial expression images. While CEM could be used to explain the results on images described with a reduced number of features, LIME would be the method of choice when dealing with images described with a huge number of features.
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  • 文章类型: Journal Article
    在本文中,讨论了识别不良事件的问题。这些事件在历史数据中可能表现不佳,从过去的例子中学习主要是不可能的。所讨论的问题是在两个用例的背景下考虑的,其中分析了无线传感器收集的振动和温度测量。这些用例包括燃煤电厂的破碎机和钢铁厂转炉的龙门架。的意识,由于与工业界的合作,需要一个系统,在冷启动条件下工作,不会淹没机器操作员的警报是提出一种新的预测性维护方法的动机。所提出的解决方案基于离群值识别方法。这些方法被应用于被转换成多维特征向量的所收集的数据。所提出的解决方案的新颖性源于创建减少假阳性警报的方法,它被应用于识别不良事件的系统。这种方法是基于系统对分析数据的适应性,与调度员的互动,以及XAI(eXplainable人工智能)方法的使用。在多个数据集上进行的实验表明,与独立的离群值检测方法的性能相比,所提出的方法平均将误报减少了90.25%。获得的结果允许将开发的方法实施到在实际工业设施中运行的系统。所进行的研究对于具有冷启动问题的系统可能是有价值的,其中频繁的警报可能导致用户对系统的劝阻和忽视。
    In this paper, the problem of the identification of undesirable events is discussed. Such events can be poorly represented in the historical data, and it is predominantly impossible to learn from past examples. The discussed issue is considered in the work in the context of two use cases in which vibration and temperature measurements collected by wireless sensors are analysed. These use cases include crushers at a coal-fired power plant and gantries in a steelworks converter. The awareness, resulting from the cooperation with industry, of the need for a system that works in cold start conditions and does not flood the machine operator with alarms was the motivation for proposing a new predictive maintenance method. The proposed solution is based on the methods of outlier identification. These methods are applied to the collected data that was transformed into a multidimensional feature vector. The novelty of the proposed solution stems from the creation of a methodology for the reduction of false positive alarms, which was applied to a system identifying undesirable events. This methodology is based on the adaptation of the system to the analysed data, the interaction with the dispatcher, and the use of the XAI (eXplainable Artificial Intelligence) method. The experiments performed on several data sets showed that the proposed method reduced false alarms by 90.25% on average in relation to the performance of the stand-alone outlier detection method. The obtained results allowed for the implementation of the developed method to a system operating in a real industrial facility. The conducted research may be valuable for systems with a cold start problem where frequent alarms can lead to discouragement and disregard for the system by the user.
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