arXiv subjects

Zuohua Zhang

Publications and source records attributed to Zuohua Zhang.

3 recordsLinked to original sources

arXiv2022

Joint Optimization and Statistical Inference for Zero-th Order Simulation Optimization

We consider stochastic optimization problems with the dual tasks of (i) effectively finding the optimizer and (ii) reliably conducting statistical inference for the optimal objective function value. We find that classical simulation optimization and stochastic optimization algorithms, despite of their fast convergence rates to the optimizer under strong convexity assumptions, may not come with a valid central limit theorem (CLT) with a vanishing bias. This non-vanishing bias can harm statistical inference and the construction of asymptotically valid confidence intervals. We fix this issue by providing a new stochastic optimization algorithm that on one hand maintains the same fast convergence rate and on the other hand permits the establishment of a valid CLT with vanishing bias. We discuss practical implementations of the proposed algorithm and conduct numerical experiments to illustrate the theoretical findings.

stat.ME↗

arXiv2019

ProductNet: a Collection of High-Quality Datasets for Product Representation Learning

ProductNet is a collection of high-quality product datasets for better product understanding. Motivated by ImageNet, ProductNet aims at supporting product representation learning by curating product datasets of high quality with properly chosen taxonomy. In this paper, the two goals of building high-quality product datasets and learning product representation support each other in an iterative fashion: the product embedding is obtained via a multi-modal deep neural network (master model) designed to leverage product image and catalog information; and in return, the embedding is utilized via active learning (local model) to vastly accelerate the annotation process. For the labeled data, the proposed master model yields high categorization accuracy (94.7% top-1 accuracy for 1240 classes), which can be used as search indices, partition keys, and input features for machine learning models. The product embedding, as well as the fined-tuned master model for a specific business task, can also be used for various transfer learning tasks.

cs.LG↗

arXiv2019

Reference Product Search

For a product of interest, we propose a search method to surface a set of reference products. The reference products can be used as candidates to support downstream modeling tasks and business applications. The search method consists of product representation learning and fingerprint-type vector searching. The product catalog information is transformed into a high-quality embedding of low dimensions via a novel attention auto-encoder neural network, and the embedding is further coupled with a binary encoding vector for fast retrieval. We conduct extensive experiments to evaluate the proposed method, and compare it with peer services to demonstrate its advantage in terms of search return rate and precision.

stat.ML↗