机器学习理论中的主要开放问题之一是表征过度参数化的政权中的概括,在该制度中,大多数传统的概括范围变得不一致。在许多情况下,它们的失败可以归因于掩盖训练算法与基础数据分布之间的关键相互作用。为了解决这一缺点,我们提出了一个名为兼容性的概念,该概念以与数据相关的和算法相关的方式定量地表征了概括。通过考虑整个训练轨迹并专注于早期迭代的迭代术,兼容性充分利用了算法信息,因此可以提供更好的概括保证。我们通过理论上研究与梯度下降过度参数化的线性回归设置的兼容性来验证这一点。具体而言,我们执行与数据相关的轨迹分析,并在这种设置下得出足够的兼容性条件。我们的理论结果表明,从兼容性的意义上讲,概括性对问题实例的限制明显弱,而不是上次迭代分析。
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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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机器学习(ML)研究通常集中在模型上,而最突出的数据集已用于日常的ML任务,而不考虑这些数据集对基本问题的广度,困难和忠诚。忽略数据集的基本重要性已引起了重大问题,该问题涉及现实世界中的数据级联以及数据集驱动标准的模型质量饱和,并阻碍了研究的增长。为了解决此问题,我们提出Dataperf,这是用于评估ML数据集和数据集工作算法的基准软件包。我们打算启用“数据棘轮”,其中培训集将有助于评估相同问题的测试集,反之亦然。这种反馈驱动的策略将产生一个良性的循环,该循环将加速以数据为中心的AI。MLCommons协会将维护Dataperf。
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在使用多模式贝叶斯后部分布时,马尔可夫链蒙特卡罗(MCMC)算法难以在模式之间移动,并且默认变分或基于模式的近似推动将低估后不确定性。并且,即使找到最重要的模式,难以评估后部的相对重量。在这里,我们提出了一种使用MCMC,变分或基于模式的模式的并行运行的方法,以便尽可能多地击中多种模式或分离的区域,然后使用贝叶斯堆叠来组合这些用于构建分布的加权平均值的可扩展方法。通过堆叠从多模式后分布的堆叠,最小化交叉验证预测误差的结果,并且代表了比变分推断更好的不确定度,但它不一定是相当于渐近的,以完全贝叶斯推断。我们呈现理论一致性,其中堆叠推断逼近来自未衰退的模型和非混合采样器的真实数据生成过程,预测性能优于完全贝叶斯推断,因此可以被视为祝福而不是模型拼写下的诅咒。我们展示了几个模型家庭的实际实施:潜在的Dirichlet分配,高斯过程回归,分层回归,马蹄素变量选择和神经网络。
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重要的加权是调整蒙特卡洛集成以说明错误分布中抽取的一种一般方法,但是当重要性比的右尾巴较重时,最终的估计值可能是高度可变的。当目标分布的某些方面无法通过近似分布捕获,在这种情况下,可以通过修改极端重要性比率来获得更稳定的估计。我们提出了一种新的方法,该方法使用拟合模拟重要性比率的上尾的广义帕累托分布来稳定重要性权重。该方法在经验上的性能要比现有方法稳定重要性采样估计值更好,包括稳定的有效样本量估计,蒙特卡洛误差估计和收敛诊断。提出的帕累托$ \ hat {k} $有限样本收敛率诊断对任何蒙特卡洛估计器都有用。
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The recent increase in public and academic interest in preserving biodiversity has led to the growth of the field of conservation technology. This field involves designing and constructing tools that utilize technology to aid in the conservation of wildlife. In this article, we will use case studies to demonstrate the importance of designing conservation tools with human-wildlife interaction in mind and provide a framework for creating successful tools. These case studies include a range of complexities, from simple cat collars to machine learning and game theory methodologies. Our goal is to introduce and inform current and future researchers in the field of conservation technology and provide references for educating the next generation of conservation technologists. Conservation technology not only has the potential to benefit biodiversity but also has broader impacts on fields such as sustainability and environmental protection. By using innovative technologies to address conservation challenges, we can find more effective and efficient solutions to protect and preserve our planet's resources.
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A Digital Twin (DT) is a simulation of a physical system that provides information to make decisions that add economic, social or commercial value. The behaviour of a physical system changes over time, a DT must therefore be continually updated with data from the physical systems to reflect its changing behaviour. For resource-constrained systems, updating a DT is non-trivial because of challenges such as on-board learning and the off-board data transfer. This paper presents a framework for updating data-driven DTs of resource-constrained systems geared towards system health monitoring. The proposed solution consists of: (1) an on-board system running a light-weight DT allowing the prioritisation and parsimonious transfer of data generated by the physical system; and (2) off-board robust updating of the DT and detection of anomalous behaviours. Two case studies are considered using a production gas turbine engine system to demonstrate the digital representation accuracy for real-world, time-varying physical systems.
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Knowledge graph embedding (KGE), which maps entities and relations in a knowledge graph into continuous vector spaces, has achieved great success in predicting missing links in knowledge graphs. However, knowledge graphs often contain incomplete triples that are difficult to inductively infer by KGEs. To address this challenge, we resort to analogical inference and propose a novel and general self-supervised framework AnKGE to enhance KGE models with analogical inference capability. We propose an analogical object retriever that retrieves appropriate analogical objects from entity-level, relation-level, and triple-level. And in AnKGE, we train an analogy function for each level of analogical inference with the original element embedding from a well-trained KGE model as input, which outputs the analogical object embedding. In order to combine inductive inference capability from the original KGE model and analogical inference capability enhanced by AnKGE, we interpolate the analogy score with the base model score and introduce the adaptive weights in the score function for prediction. Through extensive experiments on FB15k-237 and WN18RR datasets, we show that AnKGE achieves competitive results on link prediction task and well performs analogical inference.
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Temporal sentence grounding (TSG) aims to identify the temporal boundary of a specific segment from an untrimmed video by a sentence query. All existing works first utilize a sparse sampling strategy to extract a fixed number of video frames and then conduct multi-modal interactions with query sentence for reasoning. However, we argue that these methods have overlooked two indispensable issues: 1) Boundary-bias: The annotated target segment generally refers to two specific frames as corresponding start and end timestamps. The video downsampling process may lose these two frames and take the adjacent irrelevant frames as new boundaries. 2) Reasoning-bias: Such incorrect new boundary frames also lead to the reasoning bias during frame-query interaction, reducing the generalization ability of model. To alleviate above limitations, in this paper, we propose a novel Siamese Sampling and Reasoning Network (SSRN) for TSG, which introduces a siamese sampling mechanism to generate additional contextual frames to enrich and refine the new boundaries. Specifically, a reasoning strategy is developed to learn the inter-relationship among these frames and generate soft labels on boundaries for more accurate frame-query reasoning. Such mechanism is also able to supplement the absent consecutive visual semantics to the sampled sparse frames for fine-grained activity understanding. Extensive experiments demonstrate the effectiveness of SSRN on three challenging datasets.
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We introduce Argoverse 2 (AV2) - a collection of three datasets for perception and forecasting research in the self-driving domain. The annotated Sensor Dataset contains 1,000 sequences of multimodal data, encompassing high-resolution imagery from seven ring cameras, and two stereo cameras in addition to lidar point clouds, and 6-DOF map-aligned pose. Sequences contain 3D cuboid annotations for 26 object categories, all of which are sufficiently-sampled to support training and evaluation of 3D perception models. The Lidar Dataset contains 20,000 sequences of unlabeled lidar point clouds and map-aligned pose. This dataset is the largest ever collection of lidar sensor data and supports self-supervised learning and the emerging task of point cloud forecasting. Finally, the Motion Forecasting Dataset contains 250,000 scenarios mined for interesting and challenging interactions between the autonomous vehicle and other actors in each local scene. Models are tasked with the prediction of future motion for "scored actors" in each scenario and are provided with track histories that capture object location, heading, velocity, and category. In all three datasets, each scenario contains its own HD Map with 3D lane and crosswalk geometry - sourced from data captured in six distinct cities. We believe these datasets will support new and existing machine learning research problems in ways that existing datasets do not. All datasets are released under the CC BY-NC-SA 4.0 license.
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