Accuracy at the top is a special class of binary classification problems where the performance is evaluated only on a small number of relevant (top) samples. Applications include information retrieval systems or processes with manual (expensive) postprocessing. This leads to minimizing the number of irrelevant samples above a threshold. We consider classifiers in the form of an arbitrary (deep) network and propose a new method DeepTopPush for minimizing the loss function at the top. Since the threshold depends on all samples, the problem is non-decomposable. We modify the stochastic gradient descent to handle the non-decomposability in an end-to-end training manner and propose a way to estimate the threshold only from values on the current minibatch and one delayed value. We demonstrate the excellent performance of DeepTopPush on visual recognition datasets and two real-world applications. The first one selects a small number of molecules for further drug testing. The second one uses real malware data, where we detected 46\% malware at an extremely low false alarm rate of $10^{-5}$.
Top-N-Rank: A Scalable List-wise Ranking Method for Recommender Systems
Pennsylvania State University(宾夕法尼亚州立大学);South China University of Technology(华南理工大学)
我们提出了Top-N-Rank,一种新颖的列表式学习排名模型,用于可靠地推荐N个排名靠前的项目。所提出的模型优化了广泛使用的折扣累积增益(DCG)目标函数的变体,其在两个重要方面不同于DCG:(i)它将DCG的评估仅限于排名列表中的前N个项目,从而消除了低排名项目对学习的排名函数的影响;以及(ii)它结合了允许模型利用具有不同可靠性或可信度级别的多种类型的隐式反馈的权重。由于得到的目标函数是非光滑的,因此优化具有挑战性,我们考虑使用传统的S形函数和校正线性单元(ReLU)对目标函数进行两个光滑近似。我们提出了一个家庭的学习排名算法(Top-N-Rank),工作与任何光滑的目标函数。然后,引入了一个更有效的变体Top-N-Rank.ReLU,该变体有效地利用了ReLU函数的性质,将Top-N-Rank的计算复杂性从用户评分的平均项目数的二次降低到线性。我们使用两个广泛使用的基准测试,即MovieLens数据集和Amazon Video Games数据集的实验结果表明:(i)目标函数的“top-N截断”大大提高了前N个推荐的排名质量;(ii)与使用sigmoid相比,使用ReLU来平滑目标函数在排名质量和运行时间方面都有显着改善;以及(iii)Top-N-Rank.ReLU在排名质量方面大大优于表现良好的列表式排名方法。
HATA: Trainable and Hardware-Efficient Hash-Aware Top-k Attention for Scalable Large Model Inference
University of Science and Technology of China(中国科学技术大学);Institute of Artificial Intelligence(人工智能研究院);Hefei Comprehensive National Science Center(合肥综合性国家科学中心);Huawei Technologies(华为技术有限公司);Peking University(北京大学)