知识图形问题应答(kgqa)涉及使用自然语言查询从知识图(kg)中检索事实。 KG是由关系相关的实体组成的策划事实集。某些事实还包括形成时间kg(tkg)的时间信息。虽然许多自然问题涉及显式或隐含的时间限制,但TKGS上的问题应答(QA)是一个相对未开发的地区。现有解决方案主要是为简单的时间问题设计,可以通过单个TKG事实直接回答。本文提出了一种全面的嵌入式框架,用于回答TKGS的复杂问题。我们的方法被称为时间问题推理(TempoQR)利用TKG Embeddings将问题与其指的特定实体和时间范围进行地面。它通过使用三个专用模块增强与上下文,实体和时空信息的问题嵌入问题。第一个计算给定问题的文本表示,第二个将其与所涉及的实体的实体嵌入物组合,第三个生成特定于特定于问题的时间嵌入。最后,基于变换器的编码器学习用问题表示来融合生成的时间信息,该问题表示用于答案预测。广泛的实验表明,TempoQR在最先进的方法上通过25-45个百分点提高了25--45个百分点,并且它将更好地概括到未经说明的问题类型。
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This paper describes important considerations and challenges associated with online reinforcement-learning based waveform selection for target identification in frequency modulated continuous wave (FMCW) automotive radar systems. We present a novel learning approach based on satisficing Thompson sampling, which quickly identifies a waveform expected to yield satisfactory classification performance. We demonstrate through measurement-level simulations that effective waveform selection strategies can be quickly learned, even in cases where the radar must select from a large catalog of candidate waveforms. The radar learns to adaptively select a bandwidth for appropriate resolution and a slow-time unimodular code for interference mitigation in the scene of interest by optimizing an expected classification metric.
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感知,规划,估算和控制的当代方法允许机器人在不确定,非结构化环境中的远程代理中稳健运行。此进度现在创造了机器人不仅在隔离,而且在我们的复杂环境中运行的机器人。意识到这个机会需要一种高效且灵活的媒介,人类可以与协作机器人沟通。自然语言提供了一种这样的媒体,通过对自然语言理解的统计方法的重大进展,现在能够解释各种自由形式命令。然而,大多数当代方法需要机器人环境的详细,现有的空间语义地图,这些环境模拟了话语可能引用的可能引用的空间。因此,当机器人部署在新的,先前未知或部分观察到的环境中时,这些方法发生故障,特别是当环境的心理模型在人类运营商和机器人之间不同时。本文提供了一种新的学习框架的全面描述,允许现场和服务机器人解释并正确执行先验未知,非结构化环境中的自然语言指令。对于我们的方法而不是我们的语言作为“传感器” - 在话语中隐含的“传感器” - 推断的空间,拓扑和语义信息,然后利用这些信息来学习在潜在环境模型上的分布。我们将此分布纳入概率,语言接地模型中,并在机器人的动作空间的象征性表示中推断出分布。我们使用模仿学习来确定对环境和行为分布的原因的信仰空间政策。我们通过各种导航和移动操纵实验评估我们的框架。
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我们提出了置信度序列 - 置信区间序列,其均匀地随时间均匀 - 用于基于I.I.D的流的完整,完全有序集中的任何分布的量级。观察。我们提供用于跟踪固定定量的方法并同时跟踪所有定量。具体而言,我们提供具有小常数的明确表达式,其宽度以尽可能快的$ \ SQRT {t} \ log \ log t} $率,以及实证分布函数的非渐近浓度不等式以相同的速率均匀地持续持续。后者加强了Smirnov迭代对数的实证过程法,延长了DVORETZKY-KIEFER-WOLFOITZ不等式以均匀地保持一段时间。我们提供了一种新的算法和样本复杂性,用于在多武装强盗框架中选择具有大约最佳定量的臂。在仿真中,我们的方法需要比现有方法更少五到五十的样品。
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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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We consider infinite horizon Markov decision processes (MDPs) with fast-slow structure, meaning that certain parts of the state space move "fast" (and in a sense, are more influential) while other parts transition more "slowly." Such structure is common in real-world problems where sequential decisions need to be made at high frequencies, yet information that varies at a slower timescale also influences the optimal policy. Examples include: (1) service allocation for a multi-class queue with (slowly varying) stochastic costs, (2) a restless multi-armed bandit with an environmental state, and (3) energy demand response, where both day-ahead and real-time prices play a role in the firm's revenue. Models that fully capture these problems often result in MDPs with large state spaces and large effective time horizons (due to frequent decisions), rendering them computationally intractable. We propose an approximate dynamic programming algorithmic framework based on the idea of "freezing" the slow states, solving a set of simpler finite-horizon MDPs (the lower-level MDPs), and applying value iteration (VI) to an auxiliary MDP that transitions on a slower timescale (the upper-level MDP). We also extend the technique to a function approximation setting, where a feature-based linear architecture is used. On the theoretical side, we analyze the regret incurred by each variant of our frozen-state approach. Finally, we give empirical evidence that the frozen-state approach generates effective policies using just a fraction of the computational cost, while illustrating that simply omitting slow states from the decision modeling is often not a viable heuristic.
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While the capabilities of autonomous systems have been steadily improving in recent years, these systems still struggle to rapidly explore previously unknown environments without the aid of GPS-assisted navigation. The DARPA Subterranean (SubT) Challenge aimed to fast track the development of autonomous exploration systems by evaluating their performance in real-world underground search-and-rescue scenarios. Subterranean environments present a plethora of challenges for robotic systems, such as limited communications, complex topology, visually-degraded sensing, and harsh terrain. The presented solution enables long-term autonomy with minimal human supervision by combining a powerful and independent single-agent autonomy stack, with higher level mission management operating over a flexible mesh network. The autonomy suite deployed on quadruped and wheeled robots was fully independent, freeing the human supervision to loosely supervise the mission and make high-impact strategic decisions. We also discuss lessons learned from fielding our system at the SubT Final Event, relating to vehicle versatility, system adaptability, and re-configurable communications.
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Machine learning is the dominant approach to artificial intelligence, through which computers learn from data and experience. In the framework of supervised learning, for a computer to learn from data accurately and efficiently, some auxiliary information about the data distribution and target function should be provided to it through the learning model. This notion of auxiliary information relates to the concept of regularization in statistical learning theory. A common feature among real-world datasets is that data domains are multiscale and target functions are well-behaved and smooth. In this paper, we propose a learning model that exploits this multiscale data structure and discuss its statistical and computational benefits. The hierarchical learning model is inspired by the logical and progressive easy-to-hard learning mechanism of human beings and has interpretable levels. The model apportions computational resources according to the complexity of data instances and target functions. This property can have multiple benefits, including higher inference speed and computational savings in training a model for many users or when training is interrupted. We provide a statistical analysis of the learning mechanism using multiscale entropies and show that it can yield significantly stronger guarantees than uniform convergence bounds.
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Implicit Neural Representations (INR) have recently shown to be powerful tool for high-quality video compression. However, existing works are limiting as they do not explicitly exploit the temporal redundancy in videos, leading to a long encoding time. Additionally, these methods have fixed architectures which do not scale to longer videos or higher resolutions. To address these issues, we propose NIRVANA, which treats videos as groups of frames and fits separate networks to each group performing patch-wise prediction. This design shares computation within each group, in the spatial and temporal dimensions, resulting in reduced encoding time of the video. The video representation is modeled autoregressively, with networks fit on a current group initialized using weights from the previous group's model. To further enhance efficiency, we perform quantization of the network parameters during training, requiring no post-hoc pruning or quantization. When compared with previous works on the benchmark UVG dataset, NIRVANA improves encoding quality from 37.36 to 37.70 (in terms of PSNR) and the encoding speed by 12X, while maintaining the same compression rate. In contrast to prior video INR works which struggle with larger resolution and longer videos, we show that our algorithm is highly flexible and scales naturally due to its patch-wise and autoregressive designs. Moreover, our method achieves variable bitrate compression by adapting to videos with varying inter-frame motion. NIRVANA achieves 6X decoding speed and scales well with more GPUs, making it practical for various deployment scenarios.
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