亚洲男人的天堂2018av,欧美草比,久久久久久免费视频精选,国色天香在线看免费,久久久久亚洲av成人片仓井空

主題: Learning Term Discrimination

摘要: 文檔索引是有效信息檢索(IR)的關鍵組件。經過諸如詞干和停用詞刪除之類的預處理步驟之后,文檔索引通常會存儲term-frequencies(tf)。與tf(僅反映一個術語在文檔中的重要性)一起,傳統的IR模型使用諸如反文檔頻率(idf)之類的術語區分值(TDV)在檢索過程中偏向于區分性術語。在這項工作中,我們建議使用淺層神經網絡學習TDV,以進行文檔索引,該淺層神經網絡可以近似TF-IDF和BM25等傳統的IR排名功能。我們的建議在nDCG和召回方面均優于傳統方法,即使很少有帶有正標簽的查詢文檔對作為學習數據。我們學到的TDV用于過濾區分度為零的詞匯,不僅可以顯著降低倒排索引的內存占用量,而且可以加快檢索過程(BM25的速度提高了3倍),而不會降低檢索質量。

付費5元查看完整內容

相關內容

SIGIR是一個展示信息檢索領域中各種新技術和新成果的重要國際論壇。

主題: Learning Colour Representations of Search Queries

摘要: 圖像搜索引擎依賴于適當設計的排名功能,這些功能可以捕獲內容語義的各個方面以及歷史上的流行。在這項工作中,我們考慮了色彩在相關性匹配過程中的作用。觀察到很大一部分用戶查詢具有與之相關的固有顏色,這促使我們開展工作。雖然某些查詢包含明確的顏色提及(例如“黑色汽車”和“黃色雛菊”),但其他查詢卻包含隱式的顏色概念(例如“天空”和“草”)。此外,顏色的基礎查詢不是到單一顏色的映射,而是顏色空間中的分布。例如,對“樹”的搜索往往會在綠色和棕色之間形成雙峰分布。我們利用歷史點擊數據為搜索查詢生成顏色表示,并提出一種遞歸神經網絡架構,將看不見的查詢編碼到顏色空間中。我們還展示了如何從印象日志中的交叉模式相關性排序器中學習該嵌入,在印象日志中單擊了結果圖像的子集。我們證明了查詢圖像顏色距離功能的使用可改善排名性能,該性能通過用戶對點擊圖像和跳過圖像的偏好來衡量。

付費5元查看完整內容

內容感知的推薦方法對于向新用戶提供有意義的推薦是必不可少的。我們提出了一種基于內容感知神經哈希的協同過濾方法,它為用戶和項生成二進制哈希碼,這樣就可以利用高效的漢明距離估計用戶項相關性。NeuHash-CF被建模為一個自動編碼器架構,由兩個用于生成用戶和項哈希碼的聯合哈希組件組成。受語義哈希的啟發,項目哈希組件直接從項目的內容信息(即,它以相同的方式生成冷啟動和可見項哈希碼)。這與現有的最先進的模型形成了對比,后者分別處理兩個項目的情況。用戶哈希碼是通過學習用戶嵌入矩陣,直接基于用戶id生成的。我們通過實驗證明,在冷啟動推薦設置中,NeuHash-CF的性能顯著優于最先進的基線,最高可達12%的NDCG和13%的MRR,而在所有項目都在訓練時出現的標準設置中,NeuHash-CF和MRR的性能均可達4%。我們的方法使用2-4倍的更短的哈希碼,同時獲得與現有技術相同或更好的性能,因此也可以顯著減少存儲空間。

付費5元查看完整內容

本文綜述了元學習在圖像分類、自然語言處理和機器人技術等領域的應用。與深度學習不同,元學習使用較少的樣本數據集,并考慮進一步改進模型泛化以獲得更高的預測精度。我們將元學習模型歸納為三類: 黑箱適應模型、基于相似度的方法模型和元學習過程模型。最近的應用集中在將元學習與貝葉斯深度學習和強化學習相結合,以提供可行的集成問題解決方案。介紹了元學習方法的性能比較,并討論了今后的研究方向。

付費5元查看完整內容

題目: Learning Representations For Images With Hierarchical Labels

摘要:

圖像分類已經得到了廣泛的研究,但是除了傳統的圖像標簽對之外,在使用非常規的外部指導來訓練這些模型方面的工作還很有限。在本文中,我們提出了一組利用類標簽引起的語義層次信息的方法。在論文的第一部分,我們將標簽層次知識注入到任意的分類器中,并通過實驗證明,將這些外部語義信息與圖像的視覺語義相結合,可以提高整體性能。在這個方向上更進一步,我們使用自然語言中流行的基于保留順序的嵌入模型來更明確地建模標簽-標簽和標簽-圖像的交互,并將它們裁剪到計算機視覺領域來執行圖像分類。盡管在本質上與之相反,在新提出的、真實世界的ETH昆蟲學收集圖像數據集上,注入層次信息的CNN分類器和基于嵌入的模型都優于不可知層次的模型。

付費5元查看完整內容

元學習已被提出作為一個框架來解決具有挑戰性的小樣本學習設置。關鍵的思想是利用大量相似的小樣本任務,以學習如何使基學習者適應只有少數標記的樣本可用的新任務。由于深度神經網絡(DNNs)傾向于只使用少數樣本進行過度擬合,元學習通常使用淺層神經網絡(SNNs),因此限制了其有效性。本文提出了一種新的學習方法——元轉移學習(MTL)。具體來說,“meta”是指訓練多個任務,“transfer”是通過學習每個任務的DNN權值的縮放和變換函數來實現的。此外,我們還介紹了作為一種有效的MTL學習課程的困難任務元批處理方案。我們使用(5類,1次)和(5類,5次)識別任務,在兩個具有挑戰性的小樣本學習基準上進行實驗:miniImageNet和Fewshot-CIFAR100。通過與相關文獻的大量比較,驗證了本文提出的HT元批處理方案訓練的元轉移學習方法具有良好的學習效果。消融研究還表明,這兩種成分有助于快速收斂和高精度。

地址:

//arxiv.org/abs/1812.02391

代碼:

付費5元查看完整內容

Active learning from demonstration allows a robot to query a human for specific types of input to achieve efficient learning. Existing work has explored a variety of active query strategies; however, to our knowledge, none of these strategies directly minimize the performance risk of the policy the robot is learning. Utilizing recent advances in performance bounds for inverse reinforcement learning, we propose a risk-aware active inverse reinforcement learning algorithm that focuses active queries on areas of the state space with the potential for large generalization error. We show that risk-aware active learning outperforms standard active IRL approaches on gridworld, simulated driving, and table setting tasks, while also providing a performance-based stopping criterion that allows a robot to know when it has received enough demonstrations to safely perform a task.

Despite huge success in the image domain, modern detection models such as Faster R-CNN have not been used nearly as much for video analysis. This is arguably due to the fact that detection models are designed to operate on single frames and as a result do not have a mechanism for learning motion representations directly from video. We propose a learning procedure that allows detection models such as Faster R-CNN to learn motion features directly from the RGB video data while being optimized with respect to a pose estimation task. Given a pair of video frames---Frame A and Frame B---we force our model to predict human pose in Frame A using the features from Frame B. We do so by leveraging deformable convolutions across space and time. Our network learns to spatially sample features from Frame B in order to maximize pose detection accuracy in Frame A. This naturally encourages our network to learn motion offsets encoding the spatial correspondences between the two frames. We refer to these motion offsets as DiMoFs (Discriminative Motion Features). In our experiments we show that our training scheme helps learn effective motion cues, which can be used to estimate and localize salient human motion. Furthermore, we demonstrate that as a byproduct, our model also learns features that lead to improved pose detection in still-images, and better keypoint tracking. Finally, we show how to leverage our learned model for the tasks of spatiotemporal action localization and fine-grained action recognition.

Generative Adversarial Networks (GANs) can produce images of surprising complexity and realism, but are generally modeled to sample from a single latent source ignoring the explicit spatial interaction between multiple entities that could be present in a scene. Capturing such complex interactions between different objects in the world, including their relative scaling, spatial layout, occlusion, or viewpoint transformation is a challenging problem. In this work, we propose to model object composition in a GAN framework as a self-consistent composition-decomposition network. Our model is conditioned on the object images from their marginal distributions to generate a realistic image from their joint distribution by explicitly learning the possible interactions. We evaluate our model through qualitative experiments and user evaluations in both the scenarios when either paired or unpaired examples for the individual object images and the joint scenes are given during training. Our results reveal that the learned model captures potential interactions between the two object domains given as input to output new instances of composed scene at test time in a reasonable fashion.

With the development of deep learning, Deep Metric Learning (DML) has achieved great improvements in face recognition. Specifically, the widely used softmax loss in the training process often bring large intra-class variations, and feature normalization is only exploited in the testing process to compute the pair similarities. To bridge the gap, we impose the intra-class cosine similarity between the features and weight vectors in softmax loss larger than a margin in the training step, and extend it from four aspects. First, we explore the effect of a hard sample mining strategy. To alleviate the human labor of adjusting the margin hyper-parameter, a self-adaptive margin updating strategy is proposed. Then, a normalized version is given to take full advantage of the cosine similarity constraint. Furthermore, we enhance the former constraint to force the intra-class cosine similarity larger than the mean inter-class cosine similarity with a margin in the exponential feature projection space. Extensive experiments on Labeled Face in the Wild (LFW), Youtube Faces (YTF) and IARPA Janus Benchmark A (IJB-A) datasets demonstrate that the proposed methods outperform the mainstream DML methods and approach the state-of-the-art performance.

北京阿比特科技有限公司