Hamed Khorasgani

dblp:147/1281 · DBLP profile ↗
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5ranked-venue papers in the field
2as first author
2since 2021 · last 2023
0000-0002-0892-6276ORCID · corroborated

Domains — venue-derived; a paper can count in several

Big Data, Cloud & Distributed Data Systems · 4 (2 first)Data Mining & Knowledge Discovery · 1
YearPublicationVenuePosition
2023 Uncertainty Estimation for a Dual-Embedding based Entity Extraction Service
abstract
In this paper, we present our approach for quantifying uncertainty in our dual-embedding based entity extraction system. First, we review the state-of-the-art uncertainty estimation methods. We then present our entity extraction system and discuss practical challenges of applying each of the uncertainty estimation solutions to our system. Finally, we present our uncertainty estimate approach and its performance in production. Our goal is to present the challenges and concerns that one should consider while designing an uncertainty estimation solution in the real world and, therefore, help the research community to develop more practical uncertainty estimation solutions.
Hamed Khorasgani, Namrata Ghadi, Saumil Shah, Henry Zhang
IEEE Big Data1
2021 K-nearest Multi-agent Deep Reinforcement Learning for Collaborative Tasks with a Variable Number of Agents
abstract
Traditionally, the performance of multi-agent deep reinforcement learning algorithms are demonstrated and validated in gaming environments where we often have a fixed number of agents. In many industrial applications, the number of available agents can change at any given day and even when the number of agents is known ahead of time, it is common for an agent to break during the operation and become unavailable for a period of time. In this paper, we propose a new deep reinforcement learning algorithm for multi-agent collaborative tasks with a variable number of agents. We demonstrate the application of our algorithm using a fleet management simulator developed by Hitachi to generate realistic scenarios in a production site.
Hamed Khorasgani, Haiyan Wang 0003, Hsiu-Khuern Tang, Chetan Gupta 0001
IEEE BigData1
2020 A Non-linear Function-on-Function Model for Regression with Time Series Data
abstract
In the last few decades, building regression models for non-scalar variables, including time series, text, image, and video, has attracted increasing interests of researchers from the data analytic community. In this paper, we focus on a multivariate time series regression problem. Specifically, we aim to learn mathematical mappings from multiple chronologically measured numerical variables within a certain time interval S to multiple numerical variables of interest over time interval T. Prior arts, including the multivariate regression model, the Seq2Seq model, and the functional linear models, suffer from several limitations. The first two types of models can only handle regularly observed time series. Besides, the conventional multivariate regression models tend to be biased and inefficient, as they are incapable of encoding the temporal dependencies among observations from the same time series. The sequential learning models explicitly use the same set of parameters along time, which has negative impacts on accuracy. The function-on-function linear model in functional data analysis (a branch of statistics) is insufficient to capture complex correlations among the considered time series and suffer from under-fitting easily. In this paper, we propose a general functional mapping that embraces the function-on-function linear model as a special case. We then propose a non-linear function-on-function model using the fully connected neural network to learn the mapping from data, which addresses the aforementioned concerns in the existing approaches. For the proposed model, we describe in detail the corresponding numerical implementation procedures. The effectiveness of the proposed model is demonstrated through the application to two real-world problems.
Qiyao Wang, Haiyan Wang 0003, Chetan Gupta 0001, Aniruddha Rajendra Rao, Hamed Khorasgani
IEEE BigData5
2020 Dynamic Dispatching for Large-Scale Heterogeneous Fleet via Multi-agent Deep Reinforcement Learning
abstract
Dynamic dispatching is one of the core problems for operation optimization in traditional industries such as mining, as it is about how to smartly allocate the right resources to the right place at the right time. Conventionally, the industry relies on heuristics or even human intuitions which are often short-sighted and sub-optimal solutions. Leveraging the power of AI and Internet of Things (IoT), data-driven automation is reshaping this area. However, facing its own challenges such as large-scale and heterogenous trucks running in a highly dynamic environment, it can barely adopt methods developed in other domains (e.g., ride-sharing). In this paper, we propose a novel Deep Reinforcement Learning approach to solve the dynamic dispatching problem in mining. We first develop an event-based mining simulator with parameters calibrated in real mines. Then we propose an experience-sharing Deep Q Network with a novel abstract state/action representation to learn memories from heterogeneous agents altogether and realizes learning in a centralized way. We demonstrate that the proposed methods significantly outperform the most widely adopted approaches in the industry by 5.56% in terms of productivity. The proposed approach has great potential in a broader range of industries (e.g., manufacturing, logistics) which have a large-scale of heterogenous equipment working in a highly dynamic environment, as a general framework for dynamic resource allocation.
Chi Zhang 0030, Philip Odonkor, Hamed Khorasgani, Susumu Serita, Chetan Gupta 0001, Haiyan Wang 0003
IEEE BigData4
2020 Spatio-Temporal Functional Neural Networks
abstract
Explosive growth in spatio-temporal data and its wide range of applications have attracted increasing interests of researchers in the statistical and machine learning fields. The spatio-temporal regression problem is of paramount importance from both the methodology development and real-world application perspectives. Given the observed spatially encoded time series covariates and real-valued response data samples, the goal of spatio-temporal regression is to leverage the temporal and spatial dependencies to build a mapping from covariates to response with minimized prediction error. Prior arts, including the convolutional Long Short-Term Memory (CovLSTM) and variations of the functional linear models, cannot learn the spatio-temporal information in a simple and efficient format for proper model building. In this work, we propose two novel extensions of the Functional Neural Network (FNN), a temporal regression model whose effectiveness and superior performance over alternative sequential models have been proven by many researchers. The effectiveness of the proposed spatio-temporal FNNs in handling varying spatial correlations is demonstrated in comprehensive simulation studies. The proposed models are then deployed to solve a practical and challenging precipitation prediction problem in the meteorology field.
Aniruddha Rajendra Rao, Qiyao Wang, Haiyan Wang 0003, Hamed Khorasgani, Chetan Gupta 0001
DSAA4