2024

Integrating Graceful Degradation and Recovery through Requirement-driven Adaptation.
By Chu, S., Koe, J., Garlan, D. and Kang, E.
In arXiv preprint arXiv:2401.09678, 2024.
```
@article{chu2024integrating,
  title = {Integrating Graceful Degradation and Recovery through Requirement-driven Adaptation},
  author = {Chu, Simon and Koe, Justin and Garlan, David and Kang, Eunsuk},
  journal = {arXiv preprint arXiv:2401.09678},
  year = {2024}
}
```
```
Chu, Simon and Koe, Justin and Garlan, David and Kang, Eunsuk, "Integrating Graceful Degradation and Recovery through Requirement-driven Adaptation," arXiv preprint arXiv:2401.09678 , 2024.
```

2023

Follow The Rules: Online Signal Temporal Logic Tree Search for Guided Imitation Learning in Stochastic Domains.

By Aloor, J.J., Patrikar, J., Kapoor, P., Oh, J. and Scherer, S.

In 2023 IEEE International Conference on Robotics and Automation (ICRA), pp. 1320–1326, 2023.

@inproceedings{10160953,
  author = {Aloor, Jasmine Jerry and Patrikar, Jay and Kapoor, Parv and Oh, Jean and Scherer, Sebastian},
  booktitle = {2023 IEEE International Conference on Robotics and Automation (ICRA)},
  title = {Follow The Rules: Online Signal Temporal Logic Tree Search for Guided Imitation Learning in Stochastic Domains},
  year = {2023},
  volume = {},
  number = {},
  pages = {1320-1326},
  doi = {10.1109/ICRA48891.2023.10160953},
  url = {https://ieeexplore.ieee.org/abstract/document/10160953},
  html = {https://ieeexplore.ieee.org/abstract/document/10160953},
  altmetric = {248277},
  dimensions = {true},
  selected = {true}
}

Seamlessly integrating rules in Learning-from-Demonstrations (LfD) policies is a critical requirement to enable the real-world deployment of AI agents. Recently, Signal Temporal Logic (STL) has been shown to be an effective language for encoding rules as spatio-temporal constraints. This work uses Monte Carlo Tree Search (MCTS) as a means of integrating STL specification into a vanilla LfD policy to improve constraint satisfaction. We propose augmenting the MCTS heuristic with STL robustness values to bias the tree search towards branches with higher constraint satisfaction. While the domain-independent method can be applied to integrate STL rules online into any pre-trained LfD algorithm, we choose goal-conditioned Generative Adversarial Imitation Learning as the offline LfD policy. We apply the proposed method to the domain of planning trajectories for General Aviation aircraft around a non-towered airfield. Results using the simulator trained on real-world data showcase 60 percent improved performance over baseline LfD methods that do not use STL heuristics.

Aloor, Jasmine Jerry and Patrikar, Jay and Kapoor, Parv and Oh, Jean and Scherer, Sebastian, "Follow The Rules: Online Signal Temporal Logic Tree Search for Guided Imitation Learning in Stochastic Domains,"  2023 IEEE International Conference on Robotics and Automation (ICRA), 2023.

FoundLoc: Vision-based Onboard Aerial Localization in the Wild. 2023

@misc{he2023foundloc,
  title = {FoundLoc: Vision-based Onboard Aerial Localization in the Wild},
  author = {He, Yao and Cisneros, Ivan and Keetha, Nikhil and Patrikar, Jay and Ye, Zelin and Higgins, Ian and Hu, Yaoyu and Kapoor, Parv and Scherer, Sebastian},
  year = {2023},
  eprint = {2310.16299},
  archiveprefix = {arXiv},
  primaryclass = {cs.RO},
  url = {https://arxiv.org/abs/2310.16299},
  html = {https://arxiv.org/abs/2310.16299},
  altmetric = {248277},
  dimensions = {true},
  selected = {true}
}

Robust and accurate localization for Unmanned Aerial Vehicles (UAVs) is an essential capability to achieve autonomous, long-range flights. Current methods either rely heavily on GNSS, face limitations in visual-based localization due to appearance variances and stylistic dissimilarities between camera and reference imagery, or operate under the assumption of a known initial pose. In this paper, we developed a GNSS-denied localization approach for UAVs that harnesses both Visual-Inertial Odometry (VIO) and Visual Place Recognition (VPR) using a foundation model. This paper presents a novel vision-based pipeline that works exclusively with a nadir-facing camera, an Inertial Measurement Unit (IMU), and pre-existing satellite imagery for robust, accurate localization in varied environments and conditions. Our system demonstrated average localization accuracy within a 20-meter range, with a minimum error below 1 meter, under real-world conditions marked by drastic changes in environmental appearance and with no assumption of the vehicle’s initial pose. The method is proven to be effective and robust, addressing the crucial need for reliable UAV localization in GNSS-denied environments, while also being computationally efficient enough to be deployed on resource-constrained platforms.

He, Yao and Cisneros, Ivan and Keetha, Nikhil and Patrikar, Jay and Ye, Zelin and Higgins, Ian and Hu, Yaoyu and Kapoor, Parv and Scherer, Sebastian, "FoundLoc: Vision-based Onboard Aerial Localization in the Wild,"  , 2023.

Investigating Robustness in Cyber-Physical Systems: Specification-Centric Analysis in the face of System Deviations.

By *Changjian, Z., *Kapoor, P., Meira-Goes, R., Kang, E., Garlan, D., Ganlath, A., Mishra, S. and Ammar, N.

In Under Submission, 2023.

@article{kapoor2023predicting,
  title = {Investigating Robustness in Cyber-Physical
  Systems: Specification-Centric Analysis in the face
  of System Deviations},
  author = {*Changjian, Zhang and *Kapoor, Parv and Meira-Goes, Romulo and Kang, Eunsuk and Garlan, David and Ganlath, Akila and Mishra, Shatadal and Ammar, Nejib},
  journal = {Under Submission},
  year = {2023},
  url = {https://arxiv.org/abs/2311.07462},
  html = {https://arxiv.org/abs/2311.07462},
  altmetric = {248277},
  dimensions = {true},
  selected = {true}
}


    The adoption of cyber-physical systems (CPS) is on the rise in complex physical environments, encompassing domains such as autonomous vehicles, the Internet of Things (IoT), and smart cities. A critical attribute of CPS is robustness, denoting its capacity to operate safely despite potential disruptions and uncertainties in the operating environment. This paper proposes a novel specification-based robustness, which characterizes the effectiveness of a controller in meeting a specified system requirement, articulated through Signal Temporal Logic (STL) while accounting for possible deviations in the system. This paper also proposes the robustness falsification problem based on the definition, which involves identifying minor deviations capable of violating the specified requirement. We present an innovative two-layer simulation-based analysis framework designed to identify subtle robustness violations. To assess our methodology, we devise a series of benchmark problems wherein system parameters can be adjusted to emulate various forms of uncertainties and disturbances. Initial evaluations indicate that our falsification approach proficiently identifies robustness violations, providing valuable insights for comparing robustness between conventional and reinforcement learning (RL)-based controllers

*Changjian, Zhang and *Kapoor, Parv and Meira-Goes, Romulo and Kang, Eunsuk and Garlan, David and Ganlath, Akila and Mishra, Shatadal and Ammar, Nejib, "Investigating Robustness in Cyber-Physical
Systems: Specification-Centric Analysis in the face
of System Deviations," Under Submission , 2023.

Safe Planning through Incremental Decomposition of Signal Temporal Logic.
By Kapoor, P., Meira-Goes, R. and Kang, E.
In Nasa Formal Methods (NFM) 2024, 2023.
```
@article{kapoor2023incr,
  title = {Safe Planning through Incremental Decomposition of Signal Temporal Logic},
  author = {Kapoor, Parv and Meira-Goes, Romulo and Kang, Eunsuk},
  journal = {Nasa Formal Methods (NFM) 2024},
  year = {2023}
}
```
```
Kapoor, Parv and Meira-Goes, Romulo and Kang, Eunsuk, "Safe Planning through Incremental Decomposition of Signal Temporal Logic," Nasa Formal Methods (NFM) 2024 , 2023.
```
Towards Safe ML-Based Systems in Presence of Feedback Loops.
By Biswas, S., She, Y. and Kang, E.
In Proceedings of the 1st International Workshop on Dependability and Trustworthiness of Safety-Critical Systems with Machine Learned Components, pp. 18–21, 2023.
```
@inproceedings{biswas2023towards,
  title = {Towards Safe ML-Based Systems in Presence of Feedback Loops},
  author = {Biswas, Sumon and She, Yining and Kang, Eunsuk},
  booktitle = {Proceedings of the 1st International Workshop on Dependability and Trustworthiness of Safety-Critical Systems with Machine Learned Components},
  pages = {18--21},
  year = {2023}
}
```
```
Biswas, Sumon and She, Yining and Kang, Eunsuk, "Towards Safe ML-Based Systems in Presence of Feedback Loops,"  Proceedings of the 1st International Workshop on Dependability and Trustworthiness of Safety-Critical Systems with Machine Learned Components, 2023.
```
On tolerance of discrete systems with respect to transition perturbations.
By Meira-Góes, R., Kang, E., Lafortune, S. and Tripakis, S.
In Discrete Event Dynamic Systems, vol. 33, no. 4, pp. 395–424, 2023.
```
@article{meira2023tolerance,
  title = {On tolerance of discrete systems with respect to transition perturbations},
  author = {Meira-G{\'o}es, R{\^o}mulo and Kang, Eunsuk and Lafortune, St{\'e}phane and Tripakis, Stavros},
  journal = {Discrete Event Dynamic Systems},
  volume = {33},
  number = {4},
  pages = {395--424},
  year = {2023},
  publisher = {Springer}
}
```
```
Meira-Góes, Rômulo and Kang, Eunsuk and Lafortune, Stéphane and Tripakis, Stavros, "On tolerance of discrete systems with respect to transition perturbations," Discrete Event Dynamic Systems , 2023.
```
Robustification of behavioral designs against environmental deviations.
By Zhang, C., Saluja, T., Meira-Góes, R., Bolton, M., Garlan, D. and Kang, E.
In 2023 IEEE/ACM 45th International Conference on Software Engineering (ICSE), pp. 423–434, 2023.
```
@inproceedings{zhang2023robustification,
  title = {Robustification of behavioral designs against environmental deviations},
  author = {Zhang, Changjian and Saluja, Tarang and Meira-G{\'o}es, R{\^o}mulo and Bolton, Matthew and Garlan, David and Kang, Eunsuk},
  booktitle = {2023 IEEE/ACM 45th International Conference on Software Engineering (ICSE)},
  pages = {423--434},
  year = {2023},
  organization = {IEEE}
}
```
```
Zhang, Changjian and Saluja, Tarang and Meira-Góes, Rômulo and Bolton, Matthew and Garlan, David and Kang, Eunsuk, "Robustification of behavioral designs against environmental deviations,"  2023 IEEE/ACM 45th International Conference on Software Engineering (ICSE), 2023.
```

Safe Environmental Envelopes of Discrete Systems.

By Meira-Góes, R., Dardik, I., Kang, E., Lafortune, S. and Tripakis, S.

In Computer Aided Verification, Cham, pp. 326–350, 2023.

@inproceedings{Goes:2023,
  author = {Meira-G{\'o}es, R{\^o}mulo and Dardik, Ian and Kang, Eunsuk and Lafortune, St{\'e}phane and Tripakis, Stavros},
  editor = {Enea, Constantin and Lal, Akash},
  title = {Safe Environmental Envelopes of Discrete Systems},
  booktitle = {Computer Aided Verification},
  year = {2023},
  publisher = {Springer Nature Switzerland},
  address = {Cham},
  pages = {326--350},
  isbn = {978-3-031-37706-8}
}

A safety verification task involves verifying a system against a desired safety property under certain assumptions about the environment. However, these environmental assumptions may occasionally be violated due to modeling errors or faults. Ideally, the system guarantees its critical properties even under some of these violations, i.e., the system is robust against environmental deviations. This paper proposes a notion of robustness as an explicit, first-class property of a transition system that captures how robust it is against possible deviations in the environment. We modeled deviations as a set of transitions that may be added to the original environment. Our robustness notion then describes the safety envelope of this system, i.e., it captures all sets of extra environment transitions for which the system still guarantees a desired property. We show that being able to explicitly reason about robustness enables new types of system analysis and design tasks beyond the common verification problem stated above. We demonstrate the application of our framework on case studies involving a radiation therapy interface, an electronic voting machine, a fare collection protocol, and a medical pump device.

Meira-Góes, Rômulo and Dardik, Ian and Kang, Eunsuk and Lafortune, Stéphane and Tripakis, Stavros, "Safe Environmental Envelopes of Discrete Systems,"  Computer Aided Verification, 2023.

Fortis: A Tool for Analysis and Repair of Robust Software Systems.

By Zhang, C., Dardik, I., Meira-Góes, R., Garlan, D. and Kang, E.

In Formal Methods in Computer-Aided Design, FMCAD 2023, Ames, IA, USA, October 24-27, 2023, pp. 1–9, 2023.

@inproceedings{Zhang:2023,
  author = {Zhang, Changjian and Dardik, Ian and Meira{-}G{\'{o}}es, R{\^{o}}mulo and Garlan, David and Kang, Eunsuk},
  editor = {Nadel, Alexander and Rozier, Kristin Yvonne},
  title = {Fortis: {A} Tool for Analysis and Repair of Robust Software Systems},
  booktitle = {Formal Methods in Computer-Aided Design, {FMCAD} 2023, Ames, IA, USA,
  
                    October 24-27, 2023},
  pages = {1--9},
  publisher = {{IEEE}},
  year = {2023},
  url = {https://doi.org/10.34727/2023/isbn.978-3-85448-060-0\_31},
  doi = {10.34727/2023/ISBN.978-3-85448-060-0\_31},
  timestamp = {Wed, 13 Dec 2023 14:38:51 +0100},
  biburl = {https://dblp.org/rec/conf/fmcad/ZhangDMGK23.bib},
  bibsource = {dblp computer science bibliography, https://dblp.org}
}

Zhang, Changjian and Dardik, Ian and Meira-Góes, Rômulo and Garlan, David and Kang, Eunsuk, "Fortis: A Tool for Analysis and Repair of Robust Software Systems,"  Formal Methods in Computer-Aided Design, FMCAD 2023, Ames, IA, USA,

                  October 24-27, 2023, 2023.

2022

Challenges in Close-Proximity Safe and Seamless Operation of Manned and Unmanned Aircraft in Shared Airspace.

By Patrikar, J., Dantas, J., Ghosh, S., Kapoor, P., Higgins, I., Aloor, J.J., Navarro, I., Sun, J., Stoler, B., Hamidi, M. and others.

In IEEE International Conference on Robotics and Automation (ICRA), 2022.

@article{patrikar2022challenges,
  title = {Challenges in Close-Proximity Safe and Seamless Operation of Manned and Unmanned Aircraft in Shared Airspace},
  author = {Patrikar, Jay and Dantas, Joao and Ghosh, Sourish and Kapoor, Parv and Higgins, Ian and Aloor, Jasmine J and Navarro, Ingrid and Sun, Jimin and Stoler, Ben and Hamidi, Milad and others},
  journal = {IEEE International Conference on Robotics and Automation (ICRA)},
  year = {2022},
  url = {https://arxiv.org/abs/2211.06932},
  html = {https://arxiv.org/abs/2211.06932},
  altmetric = {248277},
  dimensions = {true},
  selected = {true}
}

We propose developing an integrated system to keep autonomous unmanned aircraft safely separated and behave as expected in conjunction with manned traffic. The main goal is to achieve safe manned-unmanned vehicle teaming to improve system performance, have each (robot/human) teammate learn from each other in various aircraft operations, and reduce the manning needs of manned aircraft. The proposed system anticipates and reacts to other aircraft using natural language instructions and can serve as a co-pilot or operate entirely autonomously. We point out the main technical challenges where improvements on current state-of-the-art are needed to enable Visual Flight Rules to fully autonomous aerial operations, bringing insights to these critical areas. Furthermore, we present an interactive demonstration in a prototypical scenario with one AI pilot and one human pilot sharing the same terminal airspace, interacting with each other using language, and landing safely on the same runway. We also show a demonstration of a vision-only aircraft detection system.

Patrikar, Jay and Dantas, Joao and Ghosh, Sourish and Kapoor, Parv and Higgins, Ian and Aloor, Jasmine J and Navarro, Ingrid and Sun, Jimin and Stoler, Ben and Hamidi, Milad and others, "Challenges in Close-Proximity Safe and Seamless Operation of Manned and Unmanned Aircraft in Shared Airspace," IEEE International Conference on Robotics and Automation (ICRA) , 2022.

Requirements Engineering for Feedback Loops in Software-Intensive Systems.
By Kang, E. and Meira-Góes, R.
In 2022 IEEE 30th International Requirements Engineering Conference Workshops (REW), pp. 2–5, 2022.
```
@inproceedings{kang2022requirements,
  title = {Requirements Engineering for Feedback Loops in Software-Intensive Systems},
  author = {Kang, Eunsuk and Meira-G{\'o}es, R{\^o}mulo},
  booktitle = {2022 IEEE 30th International Requirements Engineering Conference Workshops (REW)},
  pages = {2--5},
  year = {2022},
  organization = {IEEE}
}
```
```
Kang, Eunsuk and Meira-Góes, Rômulo, "Requirements Engineering for Feedback Loops in Software-Intensive Systems,"  2022 IEEE 30th International Requirements Engineering Conference Workshops (REW), 2022.
```
Feature Interactions on Steroids: On the Composition of ML Models.
By Apel, S., Kästner, C. and Kang, E.
In IEEE Software, vol. 39, no. 3, pp. 120–124, 2022.
```
@article{apel2022feature,
  title = {Feature Interactions on Steroids: On the Composition of ML Models},
  author = {Apel, Sven and K{\"a}stner, Christian and Kang, Eunsuk},
  journal = {IEEE Software},
  volume = {39},
  number = {3},
  pages = {120--124},
  year = {2022},
  publisher = {IEEE}
}
```
```
Apel, Sven and Kästner, Christian and Kang, Eunsuk, "Feature Interactions on Steroids: On the Composition of ML Models," IEEE Software , 2022.
```

2021

Self-adaptive machine learning systems: Research challenges and opportunities.
By Casimiro, M., Romano, P., Garlan, D., Moreno, G.A., Kang, E. and Klein, M.
In European Conference on Software Architecture, pp. 133–155, 2021.
```
@inproceedings{casimiro2021self,
  title = {Self-adaptive machine learning systems: Research challenges and opportunities},
  author = {Casimiro, Maria and Romano, Paolo and Garlan, David and Moreno, Gabriel A and Kang, Eunsuk and Klein, Mark},
  booktitle = {European Conference on Software Architecture},
  pages = {133--155},
  year = {2021},
  organization = {Springer}
}
```
```
Casimiro, Maria and Romano, Paolo and Garlan, David and Moreno, Gabriel A and Kang, Eunsuk and Klein, Mark, "Self-adaptive machine learning systems: Research challenges and opportunities,"  European Conference on Software Architecture, 2021.
```
AlloyMax: bringing maximum satisfaction to relational specifications.
By Zhang, C., Wagner, R., Orvalho, P., Garlan, D., Manquinho, V., Martins, R. and Kang, E.
In Proceedings of the 29th ACM Joint Meeting on European Software Engineering Conference and Symposium on the Foundations of Software Engineering, pp. 155–167, 2021.
```
@inproceedings{zhang2021alloymax,
  title = {AlloyMax: bringing maximum satisfaction to relational specifications},
  author = {Zhang, Changjian and Wagner, Ryan and Orvalho, Pedro and Garlan, David and Manquinho, Vasco and Martins, Ruben and Kang, Eunsuk},
  booktitle = {Proceedings of the 29th ACM Joint Meeting on European Software Engineering Conference and Symposium on the Foundations of Software Engineering},
  pages = {155--167},
  year = {2021}
}
```
```
Zhang, Changjian and Wagner, Ryan and Orvalho, Pedro and Garlan, David and Manquinho, Vasco and Martins, Ruben and Kang, Eunsuk, "AlloyMax: bringing maximum satisfaction to relational specifications,"  Proceedings of the 29th ACM Joint Meeting on European Software Engineering Conference and Symposium on the Foundations of Software Engineering, 2021.
```

2020

A behavioral notion of robustness for software systems.
By Zhang, C., Garlan, D. and Kang, E.
In Proceedings of the 28th ACM Joint Meeting on European Software Engineering Conference and Symposium on the Foundations of Software Engineering, pp. 1–12, 2020.
```
@inproceedings{zhang2020behavioral,
  title = {A behavioral notion of robustness for software systems},
  author = {Zhang, Changjian and Garlan, David and Kang, Eunsuk},
  booktitle = {Proceedings of the 28th ACM Joint Meeting on European Software Engineering Conference and Symposium on the Foundations of Software Engineering},
  pages = {1--12},
  year = {2020}
}
```
```
Zhang, Changjian and Garlan, David and Kang, Eunsuk, "A behavioral notion of robustness for software systems,"  Proceedings of the 28th ACM Joint Meeting on European Software Engineering Conference and Symposium on the Foundations of Software Engineering, 2020.
```

2019

Trade-off-oriented development: making quality attribute trade-offs first-class.
By Dürschmid, T., Kang, E. and Garlan, D.
In 2019 IEEE/ACM 41st International Conference on Software Engineering: New Ideas and Emerging Results (ICSE-NIER), pp. 109–112, 2019.
```
@inproceedings{durschmid2019trade,
  title = {Trade-off-oriented development: making quality attribute trade-offs first-class},
  author = {D{\"u}rschmid, Tobias and Kang, Eunsuk and Garlan, David},
  booktitle = {2019 IEEE/ACM 41st International Conference on Software Engineering: New Ideas and Emerging Results (ICSE-NIER)},
  pages = {109--112},
  year = {2019},
  organization = {IEEE}
}
```
```
Dürschmid, Tobias and Kang, Eunsuk and Garlan, David, "Trade-off-oriented development: making quality attribute trade-offs first-class,"  2019 IEEE/ACM 41st International Conference on Software Engineering: New Ideas and Emerging Results (ICSE-NIER), 2019.
```