Incorporating external knowledge into the response generation process is essential to building more helpful and reliable dialog agents. However, collecting knowledge-grounded conversations is often costly, calling for a better pre-trained model for grounded dialog generation that generalizes well w.r.t. different types of knowledge. In this work, we propose KPT (Keyword-guided Pre-Training), a novel self-supervised pre-training method for grounded dialog generation without relying on extra knowledge annotation. Specifically, we use a pre-trained language model to extract the most uncertain tokens in the dialog as keywords. With these keywords, we construct two kinds of knowledge and pre-train a knowledge-grounded response generation model, aiming at handling two different scenarios: (1) the knowledge should be faithfully grounded; (2) it can be selectively used. For the former, the grounding knowledge consists of keywords extracted from the response. For the latter, the grounding knowledge is additionally augmented with keywords extracted from other utterances in the same dialog. Since the knowledge is extracted from the dialog itself, KPT can be easily performed on a large volume and variety of dialogue data. We considered three data sources (open-domain, task-oriented, conversational QA) with a total of 2.5M dialogues. We conduct extensive experiments on various few-shot knowledge-grounded generation tasks, including grounding on dialog acts, knowledge graphs, persona descriptions, and Wikipedia passages. Our comprehensive experiments and analyses demonstrate that KPT consistently outperforms state-of-the-art methods on these tasks with diverse grounding knowledge.
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Blind image super-resolution (Blind-SR) aims to recover a high-resolution (HR) image from its corresponding low-resolution (LR) input image with unknown degradations. Most of the existing works design an explicit degradation estimator for each degradation to guide SR. However, it is infeasible to provide concrete labels of multiple degradation combinations (\eg, blur, noise, jpeg compression) to supervise the degradation estimator training. In addition, these special designs for certain degradation, such as blur, impedes the models from being generalized to handle different degradations. To this end, it is necessary to design an implicit degradation estimator that can extract discriminative degradation representation for all degradations without relying on the supervision of degradation ground-truth. In this paper, we propose a Knowledge Distillation based Blind-SR network (KDSR). It consists of a knowledge distillation based implicit degradation estimator network (KD-IDE) and an efficient SR network. To learn the KDSR model, we first train a teacher network: KD-IDE$_{T}$. It takes paired HR and LR patches as inputs and is optimized with the SR network jointly. Then, we further train a student network KD-IDE$_{S}$, which only takes LR images as input and learns to extract the same implicit degradation representation (IDR) as KD-IDE$_{T}$. In addition, to fully use extracted IDR, we design a simple, strong, and efficient IDR based dynamic convolution residual block (IDR-DCRB) to build an SR network. We conduct extensive experiments under classic and real-world degradation settings. The results show that KDSR achieves SOTA performance and can generalize to various degradation processes. The source codes and pre-trained models will be released.
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The 1$^{\text{st}}$ Workshop on Maritime Computer Vision (MaCVi) 2023 focused on maritime computer vision for Unmanned Aerial Vehicles (UAV) and Unmanned Surface Vehicle (USV), and organized several subchallenges in this domain: (i) UAV-based Maritime Object Detection, (ii) UAV-based Maritime Object Tracking, (iii) USV-based Maritime Obstacle Segmentation and (iv) USV-based Maritime Obstacle Detection. The subchallenges were based on the SeaDronesSee and MODS benchmarks. This report summarizes the main findings of the individual subchallenges and introduces a new benchmark, called SeaDronesSee Object Detection v2, which extends the previous benchmark by including more classes and footage. We provide statistical and qualitative analyses, and assess trends in the best-performing methodologies of over 130 submissions. The methods are summarized in the appendix. The datasets, evaluation code and the leaderboard are publicly available at https://seadronessee.cs.uni-tuebingen.de/macvi.
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在微创手术中,视频分析的手术工作流程分割是一个经过深入研究的主题。常规方法将其定义为多类分类问题,其中各个视频帧被归因于手术期标签。我们引入了一种新颖的加强学习公式,以用于离线相过渡检索。我们没有尝试对每个视频框架进行分类,而是确定每个相转换的时间戳。通过构造,我们的模型不会产生虚假和嘈杂的相变,而是相邻的相位块。我们研究了该模型的两种不同配置。第一个不需要在视频中处理所有帧(在2个不同的应用程序中仅<60%和<20%的帧),而在最新的精度下略微产生结果。第二个配置处理所有视频帧,并以可比的计算成本优于最新技术。 We compare our method against the recent top-performing frame-based approaches TeCNO and Trans-SVNet on the public dataset Cholec80 and also on an in-house dataset of laparoscopic sacrocolpopexy.我们同时执行基于框架的(准确性,精度,召回和F1得分),也可以对我们的算法进行基于事件的(事件比率)评估。
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医学图像分析中使用的深度学习模型很容易由于其黑盒性质而引起的可靠性问题。为了阐明这些黑盒模型,先前的作品主要集中在识别输入特征对诊断的贡献,即功能归因。在这项工作中,我们探讨了反事实解释,以确定模型依赖于诊断的模式。具体而言,我们研究了胸部X射线内变化特征对分类器输出的影响,以了解其决策机制。我们利用一种基于样式的方法(StyleEx)来通过操纵其潜在空间中的特定潜在方向来为胸部X射线射线创建反事实解释。此外,我们建议本本芬大大减少生成解释的计算时间。我们在放射科医生的帮助下临床评估反事实解释的相关性。我们的代码公开可用。
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基于密度的分布(OOD)检测最近显示了检测OOD图像的任务不可靠。基于各种密度比的方法实现了良好的经验性能,但是方法通常缺乏原则性的概率建模解释。在这项工作中,我们建议在建立基于能量的模型并采用不同基础分布的新框架下统一基于密度比的方法。在我们的框架下,密度比可以看作是隐式语义分布的非均衡密度。此外,我们建议通过类比率估计直接估计数据样本的密度比。与最近的工作相比,我们报告了有关OOD图像问题的竞争结果,这些工作需要对任务进行深层生成模型的培训。我们的方法使一个简单而有效的途径可以解决OOD检测问题。
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预测短期交互会话的下一个交互是基于会话的推荐中的一个具有挑战性的任务。几乎所有现有的作品都依赖于项目转换模式,并在建模用户偏好时忽略用户历史会话的影响,这通常会导致非个性化推荐。此外,基于现有的个性化会话的推荐人仅基于当前用户的会话捕获用户首选项,而是忽略来自其他用户的历史会话的有用物品转换模式。为了解决这些问题,我们提出了一种新颖的异构全球图形神经网络(HG-GNN)以以微妙的方式利用所有会话的物品过渡,以便更好地推断用户偏好与当前和历史会话。为了有效利用所有用户的所有会话转换,我们提出了一种新的异构全局图,该图包含会话,用户项交互和全局共同发生项目的项目转换。此外,为了综合地从会话中捕获用户偏好,我们建议通过两个图形增强偏好编码器学习来自全局图的两个用户表示。具体地,我们在异构全球图上设计一种新的异构图形神经网络(HGNN),以了解具有丰富语义的长期用户偏好和项目表示。基于HGNN,我们提出了当前偏好编码器和历史偏好编码器,分别捕获来自当前和历史会话的不同级别的用户偏好。为实现个性化建议,我们将用户当前偏好和历史利益的表示集成到生成最终用户首选项表示。三个真实数据集的广泛实验结果表明,我们的模型优于其他最先进的方法。
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学习脱消自然语言的表示对于许多NLP任务至关重要,例如,条件文本生成,样式转移,个性化对话系统等。已经广泛研究了类似的问题,以其他形式的数据,例如图像和视频。然而,自然语言的离散性质使得脱屑更具挑战性(例如,无法轻易实现数据空间的操纵)。受到信息理论的启发,我们提出了一种新的方法,有效地体现了案文的解散表示,没有任何关于语义的监督。派生和利用新的相互信息上限以测量风格和内容之间的依赖。通过最小化该上限,提出的方法将嵌入式和内容嵌入到两个独立的低维空间中。条件文本生成和文本式转移的实验表明了在内容和风格保存方面的高质量。
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Conditional variational models, using either continuous or discrete latent variables, are powerful for open-domain dialogue response generation. However, previous works show that continuous latent variables tend to reduce the coherence of generated responses. In this paper, we also found that discrete latent variables have difficulty capturing more diverse expressions. To tackle these problems, we combine the merits of both continuous and discrete latent variables and propose a Hybrid Latent Variable (HLV) method. Specifically, HLV constrains the global semantics of responses through discrete latent variables and enriches responses with continuous latent variables. Thus, we diversify the generated responses while maintaining relevance and coherence. In addition, we propose Conditional Hybrid Variational Transformer (CHVT) to construct and to utilize HLV with transformers for dialogue generation. Through fine-grained symbolic-level semantic information and additive Gaussian mixing, we construct the distribution of continuous variables, prompting the generation of diverse expressions. Meanwhile, to maintain the relevance and coherence, the discrete latent variable is optimized by self-separation training. Experimental results on two dialogue generation datasets (DailyDialog and Opensubtitles) show that CHVT is superior to traditional transformer-based variational mechanism w.r.t. diversity, relevance and coherence metrics. Moreover, we also demonstrate the benefit of applying HLV to fine-tuning two pre-trained dialogue models (PLATO and BART-base).
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Complex dialogue mappings (CDM), including one-to-many and many-to-one mappings, tend to make dialogue models generate incoherent or dull responses, and modeling these mappings remains a huge challenge for neural dialogue systems. To alleviate these problems, methods like introducing external information, reconstructing the optimization function, and manipulating data samples are proposed, while they primarily focus on avoiding training with CDM, inevitably weakening the model's ability of understanding CDM in human conversations and limiting further improvements in model performance. This paper proposes a Sentence Semantic \textbf{Seg}mentation guided \textbf{C}onditional \textbf{V}ariational \textbf{A}uto-\textbf{E}ncoder (SegCVAE) method which can model and take advantages of the CDM data. Specifically, to tackle the incoherent problem caused by one-to-many, SegCVAE uses response-related prominent semantics to constrained the latent variable. To mitigate the non-diverse problem brought by many-to-one, SegCVAE segments multiple prominent semantics to enrich the latent variables. Three novel components, Internal Separation, External Guidance, and Semantic Norms, are proposed to achieve SegCVAE. On dialogue generation tasks, both the automatic and human evaluation results show that SegCVAE achieves new state-of-the-art performance.
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