Search Results for author: Naira Hovakimyan

Found 56 papers, 12 papers with code

Towards a Robust Retrieval-Based Summarization System

1 code implementation29 Mar 2024 ShengJie Liu, Jing Wu, Jingyuan Bao, Wenyi Wang, Naira Hovakimyan, Christopher G Healey

SummRAG is an example of our goal of defining structured methods to test the capabilities of an LLM, rather than addressing issues in a one-off fashion.

Retrieval

The New Agronomists: Language Models are Experts in Crop Management

1 code implementation28 Mar 2024 Jing Wu, Zhixin Lai, Suiyao Chen, Ran Tao, Pan Zhao, Naira Hovakimyan

A novel aspect of our approach is the conversion of these state variables into more informative language, facilitating the language model's capacity to understand states and explore optimal management practices.

Language Modelling Management +2

Residual-based Language Models are Free Boosters for Biomedical Imaging

1 code implementation26 Mar 2024 Zhixin Lai, Jing Wu, Suiyao Chen, Yucheng Zhou, Naira Hovakimyan

In this study, we uncover the unexpected efficacy of residual-based large language models (LLMs) as part of encoders for biomedical imaging tasks, a domain traditionally devoid of language or textual data.

Robust Model Based Reinforcement Learning Using $\mathcal{L}_1$ Adaptive Control

no code implementations21 Mar 2024 Minjun Sung, Sambhu H. Karumanchi, Aditya Gahlawat, Naira Hovakimyan

Unlike model-free approaches, MBRL algorithms learn a model of the transition function using data and use it to design a control input.

Model-based Reinforcement Learning reinforcement-learning

Proto-MPC: An Encoder-Prototype-Decoder Approach for Quadrotor Control in Challenging Winds

no code implementations27 Jan 2024 Yuliang Gu, Sheng Cheng, Naira Hovakimyan

Quadrotors are increasingly used in the evolving field of aerial robotics for their agility and mechanical simplicity.

Meta-Learning Model Predictive Control

ReConTab: Regularized Contrastive Representation Learning for Tabular Data

no code implementations28 Oct 2023 Suiyao Chen, Jing Wu, Naira Hovakimyan, Handong Yao

In response to this challenge, we introduce ReConTab, a deep automatic representation learning framework with regularized contrastive learning.

Contrastive Learning Feature Engineering +2

Robust Adaptive MPC Using Uncertainty Compensation

no code implementations24 Sep 2023 Ran Tao, Pan Zhao, Ilya Kolmanovsky, Naira Hovakimyan

The performance bounds provided by the L1AC are then used to tighten the state and control constraints of the actual system, and a model predictive controller is designed for the nominal system with the tightened constraints.

Model Predictive Control

Learning Tube-Certified Control Using Robust Contraction Metrics

1 code implementation14 Sep 2023 Vivek Sharma, Pan Zhao, Naira Hovakimyan

In this paper, for nonlinear systems subject to bounded disturbances, we present a framework for jointly learning a robust nonlinear controller and a contraction metric using a novel disturbance rejection objective that certifies a universal $\mathcal L_\infty$ gain bound using NNs for user-specified variables.

GenCo: An Auxiliary Generator from Contrastive Learning for Enhanced Few-Shot Learning in Remote Sensing

no code implementations27 Jul 2023 Jing Wu, Naira Hovakimyan, Jennifer Hobbs

We demonstrate the effectiveness of our method in improving few-shot learning performance on two key remote sensing datasets: Agriculture-Vision and EuroSAT.

Contrastive Learning Earth Observation +3

Coordinated Path Following of UAVs over Time-Varying Digraphs Connected in an Integral Sense

no code implementations13 Jul 2023 Hyungsoo Kang, Isaac Kaminer, Venanzio Cichella, Naira Hovakimyan

This paper presents a new connectivity condition on the information flow between UAVs to achieve coordinated path following.

Coordinated Path Following of UAVs using Event-Triggered Communication over Time-Varying Networks with Digraph Topologies

no code implementations13 Jul 2023 Hyungsoo Kang, Isaac Kaminer, Venanzio Cichella, Naira Hovakimyan

In this article, a novel time-coordination algorithm based on event-triggered communications is proposed to achieve coordinated path-following of UAVs.

Backup Plan Constrained Model Predictive Control with Guaranteed Stability

no code implementations9 Jun 2023 Ran Tao, Hunmin Kim, Hyung-Jin Yoon, Wenbin Wan, Naira Hovakimyan, Lui Sha, Petros Voulgaris

To include this new safety concept in control problems, we formulate a feasibility maximization problem aiming to maximize the feasibility of the primary and alternative missions.

Autonomous Vehicles Computational Efficiency +1

An Information-Theoretic Analysis of Discrete-Time Control and Filtering Limitations by the I-MMSE Relationships

no code implementations18 Apr 2023 Neng Wan, Dapeng Li, Naira Hovakimyan, Petros G. Voulgaris

Fundamental limitations or performance trade-offs/limits are important properties and constraints of control and filtering systems.

Extended Agriculture-Vision: An Extension of a Large Aerial Image Dataset for Agricultural Pattern Analysis

1 code implementation4 Mar 2023 Jing Wu, David Pichler, Daniel Marley, David Wilson, Naira Hovakimyan, Jennifer Hobbs

First, we generate and release an improved version of the Agriculture-Vision dataset (Chiu et al., 2020b) to include raw, full-field imagery for greater experimental flexibility.

Benchmarking Contrastive Learning +2

Balanced Training for Sparse GANs

1 code implementation NeurIPS 2023 Yite Wang, Jing Wu, Naira Hovakimyan, Ruoyu Sun

We also introduce a new method called balanced dynamic sparse training (ADAPT), which seeks to control the BR during GAN training to achieve a good trade-off between performance and computational cost.

$\mathcal{L}_1$Quad: $\mathcal{L}_1$ Adaptive Augmentation of Geometric Control for Agile Quadrotors with Performance Guarantees

no code implementations14 Feb 2023 Zhuohuan Wu, Sheng Cheng, Pan Zhao, Aditya Gahlawat, Kasey A. Ackerman, Arun Lakshmanan, Chengyu Yang, Jiahao Yu, Naira Hovakimyan

Quadrotors that can operate safely in the presence of imperfect model knowledge and external disturbances are crucial in safety-critical applications.

Certified Robust Control under Adversarial Perturbations

no code implementations4 Feb 2023 Jinghan Yang, Hunmin Kim, Wenbin Wan, Naira Hovakimyan, Yevgeniy Vorobeychik

Autonomous systems increasingly rely on machine learning techniques to transform high-dimensional raw inputs into predictions that are then used for decision-making and control.

Decision Making

Safe and Efficient Reinforcement Learning Using Disturbance-Observer-Based Control Barrier Functions

no code implementations30 Nov 2022 Yikun Cheng, Pan Zhao, Naira Hovakimyan

Safety filters, e. g., based on control barrier functions (CBFs), provide a promising way for safe RL via modifying the unsafe actions of an RL agent on the fly.

Computational Efficiency Efficient Exploration +4

Safety Embedded Stochastic Optimal Control of Networked Multi-Agent Systems via Barrier States

no code implementations8 Oct 2022 Lin Song, Pan Zhao, Neng Wan, Naira Hovakimyan

This paper presents a novel approach for achieving safe stochastic optimal control in networked multi-agent systems (MASs).

Optimizing Crop Management with Reinforcement Learning and Imitation Learning

no code implementations20 Sep 2022 Ran Tao, Pan Zhao, Jing Wu, Nicolas F. Martin, Matthew T. Harrison, Carla Ferreira, Zahra Kalantari, Naira Hovakimyan

Moreover, the partial-observation management policies are directly deployable in the real world as they use readily available information.

Imitation Learning Management +2

Synergistic Redundancy: Towards Verifiable Safety for Autonomous Vehicles

no code implementations4 Sep 2022 Ayoosh Bansal, Simon Yu, Hunmin Kim, Bo Li, Naira Hovakimyan, Marco Caccamo, Lui Sha

The synergistic safety layer uses only verifiable and logically analyzable software to fulfill its tasks.

Autonomous Driving

Verifiable Obstacle Detection

1 code implementation30 Aug 2022 Ayoosh Bansal, Hunmin Kim, Simon Yu, Bo Li, Naira Hovakimyan, Marco Caccamo, Lui Sha

Perception of obstacles remains a critical safety concern for autonomous vehicles.

Autonomous Driving

Integrated Adaptive Control and Reference Governors for Constrained Systems with State-Dependent Uncertainties

no code implementations5 Aug 2022 Pan Zhao, Ilya Kolmanovsky, Naira Hovakimyan

The proposed framework leverages an L1 adaptive controller (L1AC) that estimates and compensates for the uncertainties, and provides guaranteed transient performance, in terms of uniform bounds on the error between actual states and inputs and those of a nominal (i. e., uncertainty-free) system.

Path Integral Methods with Stochastic Control Barrier Functions

no code implementations23 Jun 2022 Chuyuan Tao, Hyung-Jin Yoon, Hunmin Kim, Naira Hovakimyan, Petros Voulgaris

In this paper, we utilize Stochastic Control Barrier Functions (SCBFs) constraints to limit sample regions in the sample-based algorithm, ensuring safety in a probabilistic sense and improving sample efficiency with a stochastic differential equation.

Optimizing Nitrogen Management with Deep Reinforcement Learning and Crop Simulations

no code implementations21 Apr 2022 Jing Wu, Ran Tao, Pan Zhao, Nicolas F. Martin, Naira Hovakimyan

Nitrogen (N) management is critical to sustain soil fertility and crop production while minimizing the negative environmental impact, but is challenging to optimize.

Management reinforcement-learning +1

Simplified Analysis on Filtering Sensitivity Trade-offs in Continuous- and Discrete-Time Systems

no code implementations8 Apr 2022 Neng Wan, Dapeng Li, Lin Song, Naira Hovakimyan

A simplified analysis is performed on the Bode-type filtering sensitivity trade-off integrals, which capture the sensitivity characteristics of the estimate and estimation error with respect to the process input and estimated signal in continuous- and discrete-time linear time-invariant filtering systems.

Protective Mission against a Highly Maneuverable Rogue Drone Using Defense Margin Strategy

no code implementations29 Mar 2022 Minjun Sung, Christophe Johannes Hiltebrandt-McIntosh, Hunmin Kim, Naira Hovakimyan

We introduce a new concept of defense margin to complement an existing strategy and construct a control strategy that successfully solves our problem.

Guaranteed Nonlinear Tracking in the Presence of DNN-Learned Dynamics With Contraction Metrics and Disturbance Estimation

no code implementations15 Dec 2021 Pan Zhao, Ziyao Guo, Aditya Gahlawat, Hyungsoo Kang, Naira Hovakimyan

This paper presents an approach to trajectory-centric learning control based on contraction metrics and disturbance estimation for nonlinear systems subject to matched uncertainties.

Control Barrier Function Augmentation in Sampling-based Control Algorithm for Sample Efficiency

no code implementations12 Nov 2021 Chuyuan Tao, Hunmin Kim, HyungJin Yoon, Naira Hovakimyan, Petros Voulgaris

For a nonlinear stochastic path planning problem, sampling-based algorithms generate thousands of random sample trajectories to find the optimal path while guaranteeing safety by Lagrangian penalty methods.

Constrained Attack-Resilient Estimation of Stochastic Cyber-Physical Systems

no code implementations25 Sep 2021 Wenbin Wan, Hunmin Kim, Naira Hovakimyan, Petros Voulgaris

In this paper, a constrained attack-resilient estimation algorithm (CARE) is developed for stochastic cyber-physical systems.

Generalization of Safe Optimal Control Actions on Networked Multi-Agent Systems

no code implementations21 Sep 2021 Lin Song, Neng Wan, Aditya Gahlawat, Chuyuan Tao, Naira Hovakimyan, Evangelos A. Theodorou

The control action composition is achieved by taking a weighted mixture of the existing controllers according to the contribution of each component task.

$\mathcal{L}_1$ Adaptive Augmentation for Geometric Tracking Control of Quadrotors

2 code implementations14 Sep 2021 Zhuohuan Wu, Sheng Cheng, Kasey A. Ackerman, Aditya Gahlawat, Arun Lakshmanan, Pan Zhao, Naira Hovakimyan

This paper introduces an $\mathcal{L}_1$ adaptive control augmentation for geometric tracking control of quadrotors.

Tube-Certified Trajectory Tracking for Nonlinear Systems With Robust Control Contraction Metrics

1 code implementation9 Sep 2021 Pan Zhao, Arun Lakshmanan, Kasey Ackerman, Aditya Gahlawat, Marco Pavone, Naira Hovakimyan

This paper presents an approach towards guaranteed trajectory tracking for nonlinear control-affine systems subject to external disturbances based on robust control contraction metrics (CCM) that aims to minimize the $\mathcal L_\infty$ gain from the disturbances to nominal-actual trajectory deviations.

Motion Planning valid

$\mathcal{L}_1$ Adaptive Control with Switched Reference Models: Application to Learn-to-Fly

no code implementations19 Aug 2021 Steven Snyder, Pan Zhao, Naira Hovakimyan

Learn-to-Fly (L2F) is a new framework that aims to replace the traditional iterative development paradigm for aerial vehicles with a combination of real-time aerodynamic modeling, guidance, and learning control.

Robustifying Reinforcement Learning Policies with $\mathcal{L}_1$ Adaptive Control

no code implementations4 Jun 2021 Yikun Cheng, Pan Zhao, Manan Gandhi, Bo Li, Evangelos Theodorou, Naira Hovakimyan

A reinforcement learning (RL) policy trained in a nominal environment could fail in a new/perturbed environment due to the existence of dynamic variations.

reinforcement-learning Reinforcement Learning (RL)

Backup Plan Constrained Model Predictive Control

no code implementations27 Mar 2021 Hunmin Kim, HyungJin Yoon, Wenbin Wan, Naira Hovakimyan, Lui Sha, Petros Voulgaris

To incorporate this new safety concept in control problems, we formulate a feasibility maximization problem that adopts additional (virtual) input horizons toward the alternative missions on top of the input horizon toward the primary mission.

Computational Efficiency Model Predictive Control

Distributed Algorithms for Linearly-Solvable Optimal Control in Networked Multi-Agent Systems

no code implementations18 Feb 2021 Neng Wan, Aditya Gahlawat, Naira Hovakimyan, Evangelos A. Theodorou, Petros G. Voulgaris

Distributed algorithms for both discrete-time and continuous-time linearly solvable optimal control (LSOC) problems of networked multi-agent systems (MASs) are investigated in this paper.

Residue Density Segmentation for Monitoring and Optimizing Tillage Practices

no code implementations9 Feb 2021 Jennifer Hobbs, Ivan Dozier, Naira Hovakimyan

"No-till" and cover cropping are often identified as the leading simple, best management practices for carbon sequestration in agriculture.

Management Probabilistic Deep Learning

Detection and Prediction of Nutrient Deficiency Stress using Longitudinal Aerial Imagery

no code implementations17 Dec 2020 Saba Dadsetan, Gisele Rose, Naira Hovakimyan, Jennifer Hobbs

Next, we construct our proposed spatiotemporal architecture, which combines a UNet with a convolutional LSTM layer, to accurately detect regions of the field showing NDS; this approach has an impressive IOU score of 0. 53.

Semantic Segmentation

Cooperative Path Integral Control for Stochastic Multi-Agent Systems

no code implementations30 Sep 2020 Neng Wan, Aditya Gahlawat, Naira Hovakimyan, Evangelos A. Theodorou, Petros G. Voulgaris

Local control actions that rely only on agents' local observations are designed to optimize the joint cost functions of subsystems.

Compositionality of Linearly Solvable Optimal Control in Networked Multi-Agent Systems

no code implementations28 Sep 2020 Lin Song, Neng Wan, Aditya Gahlawat, Naira Hovakimyan, Evangelos A. Theodorou

The proposed approach achieves both the compositionality and optimality of control actions simultaneously within the cooperative MAS framework in both discrete- and continuous-time in a sample-efficient manner, which reduces the burden of re-computation of the optimal control solutions for the new task on the MASs.

f-Divergence Variational Inference

no code implementations NeurIPS 2020 Neng Wan, Dapeng Li, Naira Hovakimyan

This paper introduces the $f$-divergence variational inference ($f$-VI) that generalizes variational inference to all $f$-divergences.

Stochastic Optimization Variational Inference

Contraction $\mathcal{L}_1$-Adaptive Control using Gaussian Processes

no code implementations8 Sep 2020 Aditya Gahlawat, Arun Lakshmanan, Lin Song, Andrew Patterson, Zhuohuan Wu, Naira Hovakimyan, Evangelos Theodorou

We present $\mathcal{CL}_1$-$\mathcal{GP}$, a control framework that enables safe simultaneous learning and control for systems subject to uncertainties.

Gaussian Processes

SL1-Simplex: Safe Velocity Regulation of Self-Driving Vehicles in Dynamic and Unforeseen Environments

no code implementations4 Aug 2020 Yanbing Mao, Yuliang Gu, Naira Hovakimyan, Lui Sha, Petros Voulgaris

Due to the high dependence of vehicle dynamics on the driving environments, the proposed Simplex leverages the finite-time model learning to timely learn and update the vehicle model for $\mathcal{L}_{1}$ adaptive controller, when any deviation from the safety envelope or the uncertainty measurement threshold occurs in the unforeseen driving environments.

Autonomous Vehicles

L1-GP: L1 Adaptive Control with Bayesian Learning

no code implementations L4DC 2020 Aditya Gahlawat, Pan Zhao, Andrew Patterson, Naira Hovakimyan, Evangelos Theodorou

We present L1-GP, an architecture based on L1 adaptive control and Gaussian Process Regression (GPR) for safe simultaneous control and learning.

GPR regression

Learning Probabilistic Intersection Traffic Models for Trajectory Prediction

no code implementations5 Feb 2020 Andrew Patterson, Aditya Gahlawat, Naira Hovakimyan

The safety of these agents is dependent on their ability to predict collisions with other vehicles' future trajectories for replanning and collision avoidance.

Collision Avoidance Object Recognition +2

Multi-Spectral Visual Odometry without Explicit Stereo Matching

no code implementations23 Aug 2019 Weichen Dai, Yu Zhang, Donglei Sun, Naira Hovakimyan, Ping Li

Moreover, the proposed method can also provide a metric 3D reconstruction in semi-dense density with multi-spectral information, which is not available from existing multi-spectral methods.

3D Reconstruction Stereo Matching +2

Intent-Aware Probabilistic Trajectory Estimation for Collision Prediction with Uncertainty Quantification

no code implementations4 Apr 2019 Andrew Patterson, Arun Lakshmanan, Naira Hovakimyan

We show that the uncertainty region for obstacle positions can be expressed in terms of a combination of polynomials generated with Gaussian process regression.

Uncertainty Quantification

Proximity Queries for Absolutely Continuous Parametric Curves

3 code implementations13 Feb 2019 Arun Lakshmanan, Andrew Patterson, Venanzio Cichella, Naira Hovakimyan

In motion planning problems for autonomous robots, such as self-driving cars, the robot must ensure that its planned path is not in close proximity to obstacles in the environment.

Robotics Computational Geometry Graphics

Hidden Markov Model Estimation-Based Q-learning for Partially Observable Markov Decision Process

no code implementations17 Sep 2018 Hyung-Jin Yoon, Donghwan Lee, Naira Hovakimyan

The objective is to study an on-line Hidden Markov model (HMM) estimation-based Q-learning algorithm for partially observable Markov decision process (POMDP) on finite state and action sets.

Q-Learning

Cannot find the paper you are looking for? You can Submit a new open access paper.