Benjamin D. Kraske, Anshu Saksena, A. Buczak, Zachary Sunberg
{"title":"Explanation Through Reward Model Reconciliation using POMDP Tree Search","authors":"Benjamin D. Kraske, Anshu Saksena, A. Buczak, Zachary Sunberg","doi":"10.1109/ICAA58325.2023.00027","DOIUrl":"https://doi.org/10.1109/ICAA58325.2023.00027","url":null,"abstract":"As artificial intelligence (AI) algorithms are increasingly used in mission-critical applications, promoting user-trust of these systems will be essential to their success. Ensuring users understand the models over which algorithms reason promotes user trust. This work seeks to reconcile differences between the reward model that an algorithm uses for online partially observable Markov decision (POMDP) planning and the implicit reward model assumed by a human user. Action discrepancies, differences in decisions made by an algorithm and user, are leveraged to estimate a user’s objectives as expressed in weightings of a reward function.","PeriodicalId":190198,"journal":{"name":"2023 IEEE International Conference on Assured Autonomy (ICAA)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121780935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Leveraging Compositional Methods for Modeling and Verification of an Autonomous Taxi System","authors":"A. Pinto, Anthony Corso, E. Schmerling","doi":"10.1109/ICAA58325.2023.00013","DOIUrl":"https://doi.org/10.1109/ICAA58325.2023.00013","url":null,"abstract":"We apply a compositional formal modeling and verification method to an autonomous aircraft taxi system. We provide insights into the modeling approach and we identify several research areas where further development is needed. Specifically, we identify the following needs: (1) semantics of composition of viewpoints expressed in different specification languages, and tools to reason about heterogeneous declarative models; (2) libraries of formal models for autonomous systems to speed up modeling and enable efficient reasoning; (3) methods to lift verification results generated by automated reasoning tools to the specification level; (4) probabilistic contract frameworks to reason about imperfect implementations; (5) standard high-level functional architectures for autonomous systems; and (6) a theory of higher-order contracts. We believe that addressing these research needs, among others, could improve the adoption of formal methods in the design of autonomous systems including learning-enabled systems, and increase confidence in their safe operations.","PeriodicalId":190198,"journal":{"name":"2023 IEEE International Conference on Assured Autonomy (ICAA)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127413274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pengyuan Lu, I. Ruchkin, Matthew Cleaveland, O. Sokolsky, Insup Lee
{"title":"Causal Repair of Learning-Enabled Cyber-Physical Systems","authors":"Pengyuan Lu, I. Ruchkin, Matthew Cleaveland, O. Sokolsky, Insup Lee","doi":"10.1109/ICAA58325.2023.00009","DOIUrl":"https://doi.org/10.1109/ICAA58325.2023.00009","url":null,"abstract":"Models of actual causality leverage domain knowledge to generate convincing diagnoses of events that caused an outcome. It is promising to apply these models to diagnose and repair run-time property violations in cyber-physical systems (CPS) with learning-enabled components (LEC). However, given the high diversity and complexity of LECs, it is challenging to encode domain knowledge (e.g., the CPS dynamics) in a scalable actual causality model that could generate useful repair suggestions. In this paper, we focus causal diagnosis on the input/output behaviors of LECs. Specifically, we aim to identify which subset of I/O behaviors of the LEC is an actual cause for a property violation. An important by-product is a counterfactual version of the LEC that repairs the run-time property by fixing the identified problematic behaviors. Based on this insights, we design a two-step diagnostic pipeline: (1) construct and Halpern-Pearl causality model that reflects the dependency of property outcome on the component’s I/O behaviors, and (2) perform a search for an actual cause and corresponding repair on the model. We prove that our pipeline has the following guarantee: if an actual cause is found, the system is guaranteed to be repaired; otherwise, we have high probabilistic confidence that the LEC under analysis did not cause the property violation. We demonstrate that our approach successfully repairs learned controllers on a standard OpenAI Gym benchmark.","PeriodicalId":190198,"journal":{"name":"2023 IEEE International Conference on Assured Autonomy (ICAA)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129632467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taylor Bradley, Elie Alhajjar, Nathaniel D. Bastian
{"title":"Novelty Detection in Network Traffic: Using Survival Analysis for Feature Identification","authors":"Taylor Bradley, Elie Alhajjar, Nathaniel D. Bastian","doi":"10.1109/ICAA58325.2023.00010","DOIUrl":"https://doi.org/10.1109/ICAA58325.2023.00010","url":null,"abstract":"Network Intrusion Detection Systems (NIDS) are an important component of many organizations’ cyber defense, resiliency and assurance strategies. However, one downside of these systems is their reliance on known attack signatures for detection of malicious network events. When it comes to unknown attack types and zero-day exploits, even modern machine learning based NIDS often fall short. In this paper, we introduce an unconventional approach to identifying network traffic features that influence novelty detection based on survival analysis techniques. Specifically, we combine several Cox proportional hazards models and implement Kaplan-Meier estimates to predict the probability that a classifier identifies novelty after the injection of an unknown network attack at any given time. The proposed model is successful at pinpointing PSH Flag Count, ACK Flag Count, URG Flag Count, and Down/Up Ratio as the main features to impact novelty detection via Random Forest, Bayesian Ridge, and Linear Support Vector Regression classifiers.","PeriodicalId":190198,"journal":{"name":"2023 IEEE International Conference on Assured Autonomy (ICAA)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114188201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Detecting Trojaned DNNs Using Counterfactual Attributions","authors":"Karan Sikka, Indranil Sur, Susmit Jha, Anirban Roy, Ajay Divakaran","doi":"10.1109/ICAA58325.2023.00019","DOIUrl":"https://doi.org/10.1109/ICAA58325.2023.00019","url":null,"abstract":"We target the problem of detecting Trojans or backdoors in DNNs. Such models behave normally with typical inputs but produce targeted mispredictions for inputs poisoned with a Trojan trigger. Our approach is based on a novel intuition that the trigger behavior is dependent on a few ghost neurons that are activated for both input classes and trigger pattern. We use counterfactual explanations, implemented as neuron attributions, to measure significance of each neuron in switching predictions to a counter-class. We then incrementally excite these neurons and observe that the model’s accuracy drops sharply for Trojaned models as compared to benign models. We support this observation through a theoretical result that shows the attributions for a Trojaned model are concentrated in a small number of features. We encode the accuracy patterns by using a deep temporal set encoder for trojan detection that enables invariance to model architecture and a number of classes. We evaluate our approach on four US IARPA/NIST-TrojAI benchmarks with high diversity in model architectures and trigger patterns. We show consistent gains over state-of-the-art adversarial attack based model diagnosis (+5.8%absolute) and trigger reconstruction based methods (+23.5%), which often require strong assumptions on the nature of the attack.","PeriodicalId":190198,"journal":{"name":"2023 IEEE International Conference on Assured Autonomy (ICAA)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127209070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}