Learning about physical systems from quantum-enhanced experiments, relying on a quantum memory and quantum processing, can outperform learning from experiments in which only classical memory and processing are available. Whereas quantum advantages have been established for a variety of state learning tasks, quantum process learning allows for comparable advantages only with a careful problem formulation and is less understood. We establish an exponential quantum advantage for learning an unknown $n$-qubit quantum process $\mathcal{N}$. We show that a quantum memory allows to efficiently solve the following tasks: (a) learning the Pauli transfer matrix of an arbitrary $\mathcal{N}$, (b) predicting expectation values of bounded Pauli-sparse observables measured on the output of an arbitrary $\mathcal{N}$ upon input of a Pauli-sparse state, and (c) predicting expectation values of arbitrary bounded observables measured on the output of an unknown $\mathcal{N}$ with sparse Pauli transfer matrix upon input of an arbitrary state. With quantum memory, these tasks can be solved using linearly-in-$n$ many copies of the Choi state of $\mathcal{N}$, and even time-efficiently in the case of (b). In contrast, any learner without quantum memory requires exponentially-in-$n$ many queries, even when querying $\mathcal{N}$ on subsystems of adaptively chosen states and performing adaptively chosen measurements. In proving this separation, we extend existing shadow tomography upper and lower bounds from states to channels via the Choi-Jamiolkowski isomorphism. Moreover, we combine Pauli transfer matrix learning with polynomial interpolation techniques to develop a procedure for learning arbitrary Hamiltonians, which may have non-local all-to-all interactions, from short-time dynamics. Our results highlight the power of quantum-enhanced experiments for learning highly complex quantum dynamics.
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作为量子优势的应用,对动态模拟和量子机学习(QML)的关注很大,而使用QML来增强动态模拟的可能性尚未得到彻底研究。在这里,我们开发了一个框架,用于使用QML方法模拟近期量子硬件上的量子动力学。我们使用概括范围,即机器学习模型在看不见的数据上遇到的错误,以严格分析此框架内算法的训练数据要求。这提供了一种保证,就量子和数据要求而言,我们的算法是资源有效的。我们的数字具有问题大小的有效缩放,我们模拟了IBMQ-Bogota上的Trotterization的20倍。
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现代量子机学习(QML)方法涉及在训练数据集上进行各种优化参数化量子电路,并随后对测试数据集(即,泛化)进行预测。在这项工作中,我们在培训数量为N $培训数据点后,我们在QML中对QML的普遍表现进行了全面的研究。我们表明,Quantum机器学习模型的泛化误差与$ T $培训门的尺寸在$ \ sqrt {t / n} $上缩放。当只有$ k \ ll t $ gates在优化过程中经历了大量变化时,我们证明了泛化误差改善了$ \ sqrt {k / n} $。我们的结果意味着将Unitaries编制到通常使用指数训练数据的量子计算行业的多项式栅极数量,这是一项通常使用指数尺寸训练数据的大量应用程序。我们还表明,使用量子卷积神经网络的相位过渡的量子状态的分类只需要一个非常小的训练数据集。其他潜在应用包括学习量子误差校正代码或量子动态模拟。我们的工作将新的希望注入QML领域,因为较少的培训数据保证了良好的概括。
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Cartesian impedance control is a type of motion control strategy for robots that improves safety in partially unknown environments by achieving a compliant behavior of the robot with respect to its external forces. This compliant robot behavior has the added benefit of allowing physical human guidance of the robot. In this paper, we propose a C++ implementation of compliance control valid for any torque-commanded robotic manipulator. The proposed controller implements Cartesian impedance control to track a desired end-effector pose. Additionally, joint impedance is projected in the nullspace of the Cartesian robot motion to track a desired robot joint configuration without perturbing the Cartesian motion of the robot. The proposed implementation also allows the robot to apply desired forces and torques to its environment. Several safety features such as filtering, rate limiting, and saturation are included in the proposed implementation. The core functionalities are in a re-usable base library and a Robot Operating System (ROS) ros_control integration is provided on top of that. The implementation was tested with the KUKA LBR iiwa robot and the Franka Emika Robot (Panda) both in simulation and with the physical robots.
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为了使人工代理在不断变化的环境中执行有用的任务,它们必须能够检测并适应新颖性。但是,视觉新颖性检测研究通常仅在重新利用的数据集(例如最初用于对象分类的CIFAR-10)上进行评估。这种做法将新颖性限制在不同对象类型的刻板图像上。我们建议需要新的基准来代表开放世界的挑战。我们的新型NovelCraft数据集包含图像和符号世界的多模式情节数据,该数据由代理在视频游戏世界中完成POGO-Stick组装任务。在某些情节中,我们插入可能影响游戏玩法的新颖对象。新颖性在复杂场景中的大小,位置和遮挡可能会有所不同。我们基于最新的新颖性检测和广义类别发现模型,重点是全面评估。结果暗示了未来研究的机会:了解不同类型错误的特定任务成本的模型可以更有效地检测和适应开放世界中的新颖性。
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在本文中,我们研究了多语言句子嵌入的使用,以转移跨管辖区,法律制度(普通和民法),语言和域名的审判决策功能分割的预测模型(即语境)。利用原始环境之外的语言资源的机制在AI和法律中具有显着的潜在利益,因为法律制度,语言或传统之间的差异往往阻碍了更广泛的研究结果。我们使用跨语言可转换的门控复发单元(GRUS)分析使用语言无话句子表示的使用。调查不同背景之间的转移,我们开发了一种审判决策功能分割的注释方案。我们发现模特超出了他们接受培训的背景(例如,在美国的行政决定上培训的模型可以应用于意大利的刑法决定)。此外,我们发现在多种上下文上培训模型增加了鲁棒性并在评估先前看不见的上下文时提高整体性能。最后,我们发现,从所有上下文中汇集训练数据增强了模型的上下文性能。
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With the advent of Neural Style Transfer (NST), stylizing an image has become quite popular. A convenient way for extending stylization techniques to videos is by applying them on a per-frame basis. However, such per-frame application usually lacks temporal-consistency expressed by undesirable flickering artifacts. Most of the existing approaches for enforcing temporal-consistency suffers from one or more of the following drawbacks. They (1) are only suitable for a limited range of stylization techniques, (2) can only be applied in an offline fashion requiring the complete video as input, (3) cannot provide consistency for the task of stylization, or (4) do not provide interactive consistency-control. Note that existing consistent video-filtering approaches aim to completely remove flickering artifacts and thus do not respect any specific consistency-control aspect. For stylization tasks, however, consistency-control is an essential requirement where a certain amount of flickering can add to the artistic look and feel. Moreover, making this control interactive is paramount from a usability perspective. To achieve the above requirements, we propose an approach that can stylize video streams while providing interactive consistency-control. Apart from stylization, our approach also supports various other image processing filters. For achieving interactive performance, we develop a lite optical-flow network that operates at 80 Frames per second (FPS) on desktop systems with sufficient accuracy. We show that the final consistent video-output using our flow network is comparable to that being obtained using state-of-the-art optical-flow network. Further, we employ an adaptive combination of local and global consistent features and enable interactive selection between the two. By objective and subjective evaluation, we show that our method is superior to state-of-the-art approaches.
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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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The purpose of this work was to tackle practical issues which arise when using a tendon-driven robotic manipulator with a long, passive, flexible proximal section in medical applications. A separable robot which overcomes difficulties in actuation and sterilization is introduced, in which the body containing the electronics is reusable and the remainder is disposable. A control input which resolves the redundancy in the kinematics and a physical interpretation of this redundancy are provided. The effect of a static change in the proximal section angle on bending angle error was explored under four testing conditions for a sinusoidal input. Bending angle error increased for increasing proximal section angle for all testing conditions with an average error reduction of 41.48% for retension, 4.28% for hysteresis, and 52.35% for re-tension + hysteresis compensation relative to the baseline case. Two major sources of error in tracking the bending angle were identified: time delay from hysteresis and DC offset from the proximal section angle. Examination of these error sources revealed that the simple hysteresis compensation was most effective for removing time delay and re-tension compensation for removing DC offset, which was the primary source of increasing error. The re-tension compensation was also tested for dynamic changes in the proximal section and reduced error in the final configuration of the tip by 89.14% relative to the baseline case.
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Compliance in actuation has been exploited to generate highly dynamic maneuvers such as throwing that take advantage of the potential energy stored in joint springs. However, the energy storage and release could not be well-timed yet. On the contrary, for multi-link systems, the natural system dynamics might even work against the actual goal. With the introduction of variable stiffness actuators, this problem has been partially addressed. With a suitable optimal control strategy, the approximate decoupling of the motor from the link can be achieved to maximize the energy transfer into the distal link prior to launch. However, such continuous stiffness variation is complex and typically leads to oscillatory swing-up motions instead of clear launch sequences. To circumvent this issue, we investigate decoupling for speed maximization with a dedicated novel actuator concept denoted Bi-Stiffness Actuation. With this, it is possible to fully decouple the link from the joint mechanism by a switch-and-hold clutch and simultaneously keep the elastic energy stored. We show that with this novel paradigm, it is not only possible to reach the same optimal performance as with power-equivalent variable stiffness actuation, but even directly control the energy transfer timing. This is a major step forward compared to previous optimal control approaches, which rely on optimizing the full time-series control input.
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