可拍照的分子显示了可以使用光访问的两个或多个异构体形式。将这些异构体的电子吸收带分开是选择性解决特定异构体并达到高光稳态状态的关键,同时总体红色转移带来的吸收带可以限制因紫外线暴露而限制材料损害,并增加了光疗法应用中的渗透深度。但是,通过合成设计将这些属性工程为系统仍然是一个挑战。在这里,我们提出了一条数据驱动的发现管道,用于由数据集策划和使用高斯过程的多任务学习支撑的分子照片开关。在对电子过渡波长的预测中,我们证明了使用来自四个Photoswitch转变波长的标签训练的多输出高斯过程(MOGP)产生相对于单任务模型的最强预测性能,并且在操作上超过了时间依赖时间依赖性的密度理论(TD) -dft)就预测的墙壁锁定时间而言。我们通过筛选可商购的可拍摄分子库来实验验证我们提出的方法。通过此屏幕,我们确定了几个图案,这些基序显示了它们的异构体的分离电子吸收带,表现出红移的吸收,并且适用于信息传输和光电学应用。我们的策划数据集,代码以及所有型号均可在https://github.com/ryan-rhys/the-photoswitch-dataset上提供
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对于大型小分子的大型库,在考虑一系列疾病模型,测定条件和剂量范围时,详尽的组合化学筛选变得不可行。深度学习模型已实现了硅的最终技术,以预测协同得分。但是,药物组合的数据库对协同剂有偏见,这些结果不一定会概括分布不足。我们采用了使用深度学习模型的顺序模型优化搜索来快速发现与癌细胞系相比的协同药物组合,而与详尽的评估相比,筛查要少得多。在仅3轮ML引导的体外实验(包括校准圆圈)之后,我们发现,对高度协同组合进行了查询的一组药物对。进行了另外两轮ML引导实验,以确保趋势的可重复性。值得注意的是,我们重新发现药物组合后来证实将在临床试验中研究。此外,我们发现仅使用结构信息生成的药物嵌入开始反映作用机理。
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对任何大数据集的初始分析都可以分为两个阶段:(1)识别共同趋势或模式以及(2)识别偏离这些趋势的异常或异常值。我们专注于检测具有新内容的观察结果的目标,这可以提醒我们数据集中的工件,或者可能发现以前未知现象的发现。为了帮助解释和诊断这些选定的观察的新颖方面,我们建议使用产生解释的新颖性检测方法。在大图像数据集的背景下,这些解释应突出显示给定图像的哪个方面是新的(颜色,形状,纹理,内容),以人为易懂的形式。我们提出了Demud-Vis,这是通过使用卷积神经网络(CNN)提取图像特征来提供新图像内容可视化解释的第一种方法,该方法使用重建误差来检测新内容,并转换上的跨跨网络来转换。 CNN功能表示返回图像空间。我们在来自ImageNet,淡水流和火星表面的各种图像上演示了这种方法。
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While the brain connectivity network can inform the understanding and diagnosis of developmental dyslexia, its cause-effect relationships have not yet enough been examined. Employing electroencephalography signals and band-limited white noise stimulus at 4.8 Hz (prosodic-syllabic frequency), we measure the phase Granger causalities among channels to identify differences between dyslexic learners and controls, thereby proposing a method to calculate directional connectivity. As causal relationships run in both directions, we explore three scenarios, namely channels' activity as sources, as sinks, and in total. Our proposed method can be used for both classification and exploratory analysis. In all scenarios, we find confirmation of the established right-lateralized Theta sampling network anomaly, in line with the temporal sampling framework's assumption of oscillatory differences in the Theta and Gamma bands. Further, we show that this anomaly primarily occurs in the causal relationships of channels acting as sinks, where it is significantly more pronounced than when only total activity is observed. In the sink scenario, our classifier obtains 0.84 and 0.88 accuracy and 0.87 and 0.93 AUC for the Theta and Gamma bands, respectively.
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There are multiple scales of abstraction from which we can describe the same image, depending on whether we are focusing on fine-grained details or a more global attribute of the image. In brain mapping, learning to automatically parse images to build representations of both small-scale features (e.g., the presence of cells or blood vessels) and global properties of an image (e.g., which brain region the image comes from) is a crucial and open challenge. However, most existing datasets and benchmarks for neuroanatomy consider only a single downstream task at a time. To bridge this gap, we introduce a new dataset, annotations, and multiple downstream tasks that provide diverse ways to readout information about brain structure and architecture from the same image. Our multi-task neuroimaging benchmark (MTNeuro) is built on volumetric, micrometer-resolution X-ray microtomography images spanning a large thalamocortical section of mouse brain, encompassing multiple cortical and subcortical regions. We generated a number of different prediction challenges and evaluated several supervised and self-supervised models for brain-region prediction and pixel-level semantic segmentation of microstructures. Our experiments not only highlight the rich heterogeneity of this dataset, but also provide insights into how self-supervised approaches can be used to learn representations that capture multiple attributes of a single image and perform well on a variety of downstream tasks. Datasets, code, and pre-trained baseline models are provided at: https://mtneuro.github.io/ .
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Rigorous guarantees about the performance of predictive algorithms are necessary in order to ensure their responsible use. Previous work has largely focused on bounding the expected loss of a predictor, but this is not sufficient in many risk-sensitive applications where the distribution of errors is important. In this work, we propose a flexible framework to produce a family of bounds on quantiles of the loss distribution incurred by a predictor. Our method takes advantage of the order statistics of the observed loss values rather than relying on the sample mean alone. We show that a quantile is an informative way of quantifying predictive performance, and that our framework applies to a variety of quantile-based metrics, each targeting important subsets of the data distribution. We analyze the theoretical properties of our proposed method and demonstrate its ability to rigorously control loss quantiles on several real-world datasets.
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The ability to convert reciprocating, i.e., alternating, actuation into rotary motion using linkages is hindered fundamentally by their poor torque transmission capability around kinematic singularity configurations. Here, we harness the elastic potential energy of a linear spring attached to the coupler link of four-bar mechanisms to manipulate force transmission around the kinematic singularities. We developed a theoretical model to explore the parameter space for proper force transmission in slider-crank and rocker-crank four-bar kinematics. Finally, we verified the proposed model and methodology by building and testing a macro-scale prototype of a slider-crank mechanism. We expect this approach to enable the development of small-scale rotary engines and robotic devices with closed kinematic chains dealing with serial kinematic singularities, such as linkages and parallel manipulators.
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This paper considers a combination of actuation tendons and measurement strings to achieve accurate shape sensing and direct kinematics of continuum robots. Assuming general string routing, a methodical Lie group formulation for the shape sensing of these robots is presented. The shape kinematics is expressed using arc-length-dependent curvature distributions parameterized by modal functions, and the Magnus expansion for Lie group integration is used to express the shape as a product of exponentials. The tendon and string length kinematic constraints are solved for the modal coefficients and the configuration space and body Jacobian are derived. The noise amplification index for the shape reconstruction problem is defined and used for optimizing the string/tendon routing paths, and a planar simulation study shows the minimal number of strings/tendons needed for accurate shape reconstruction. A torsionally stiff continuum segment is used for experimental evaluation, demonstrating mean (maximal) end-effector absolute position error of less than 2% (5%) of total length. Finally, a simulation study of a torsionally compliant segment demonstrates the approach for general deflections and string routings. We believe that the methods of this paper can benefit the design process, sensing and control of continuum and soft robots.
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Image classification with small datasets has been an active research area in the recent past. However, as research in this scope is still in its infancy, two key ingredients are missing for ensuring reliable and truthful progress: a systematic and extensive overview of the state of the art, and a common benchmark to allow for objective comparisons between published methods. This article addresses both issues. First, we systematically organize and connect past studies to consolidate a community that is currently fragmented and scattered. Second, we propose a common benchmark that allows for an objective comparison of approaches. It consists of five datasets spanning various domains (e.g., natural images, medical imagery, satellite data) and data types (RGB, grayscale, multispectral). We use this benchmark to re-evaluate the standard cross-entropy baseline and ten existing methods published between 2017 and 2021 at renowned venues. Surprisingly, we find that thorough hyper-parameter tuning on held-out validation data results in a highly competitive baseline and highlights a stunted growth of performance over the years. Indeed, only a single specialized method dating back to 2019 clearly wins our benchmark and outperforms the baseline classifier.
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The availability of frequent and cost-free satellite images is in growing demand in the research world. Such satellite constellations as Landsat 8 and Sentinel-2 provide a massive amount of valuable data daily. However, the discrepancy in the sensors' characteristics of these satellites makes it senseless to use a segmentation model trained on either dataset and applied to another, which is why domain adaptation techniques have recently become an active research area in remote sensing. In this paper, an experiment of domain adaptation through style-transferring is conducted using the HRSemI2I model to narrow the sensor discrepancy between Landsat 8 and Sentinel-2. This paper's main contribution is analyzing the expediency of that approach by comparing the results of segmentation using domain-adapted images with those without adaptation. The HRSemI2I model, adjusted to work with 6-band imagery, shows significant intersection-over-union performance improvement for both mean and per class metrics. A second contribution is providing different schemes of generalization between two label schemes - NALCMS 2015 and CORINE. The first scheme is standardization through higher-level land cover classes, and the second is through harmonization validation in the field.
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