{"title":"FIRM-Tree: A Multidimensional Index Structure for Reprogrammable Flash Memory","authors":"Shin-Ting Wu;Pin-Jung Chen;Po-Chun Huang;Wei-Kuan Shih;Yuan-Hao Chang","doi":"10.1109/TCAD.2024.3445809","DOIUrl":"https://doi.org/10.1109/TCAD.2024.3445809","url":null,"abstract":"For many emerging data-centric computing applications, it is a key capability to efficiently store, manage, and access multidimensional data. To achieve this, many multidimensional index data structures have been proposed. However, when existing multidimensional index data structures are maintained on modern nonvolatile memories (NVMs), such as NAND flash memory, they often face challenges in effective management of multidimensional data and handling of memory medium peculiarities, such as the write-once property and the need for block reclamation of NAND flash memory. Without appropriate management, these challenges often result in serious amplification of the read/write traffic, which degrades the performance of multidimensional data structures. Motivated by the urgent needs of efficient multidimensional index data structures on modern NVMs, we propose the FIRM-tree, a time-efficient and space-economic index data structure for multidimensional point data on NAND flash memory. Unique to the prior work, the FIRM-tree holistically utilizes RAM and flash memory space, and dedicatedly leverages the page reprogrammability of modern NAND flash memory, to enhance data access performance and flash management overheads. We then verify our proposal through analytical and experimental studies, where the results are quite encouraging.","PeriodicalId":13251,"journal":{"name":"IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems","volume":"43 11","pages":"3600-3613"},"PeriodicalIF":2.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Harun Teper;Daniel Kuhse;Mario Günzel;Georg von der Brüggen;Falk Howar;Jian-Jia Chen
{"title":"Thread Carefully: Preventing Starvation in the ROS 2 Multithreaded Executor","authors":"Harun Teper;Daniel Kuhse;Mario Günzel;Georg von der Brüggen;Falk Howar;Jian-Jia Chen","doi":"10.1109/TCAD.2024.3446865","DOIUrl":"https://doi.org/10.1109/TCAD.2024.3446865","url":null,"abstract":"The robot operating system 2 (ROS 2) is a widely used collection of tools and libraries for building robot applications. It is designed to be flexible and easy to use when creating complex robot systems with many interacting components.Since its alpha version release in 2015, ROS 2 provides two options in a multithreading operating system, namely the single-threaded executor and the multithreaded executor. The single-threaded executor is starvation-free by design (i.e., every task is eventually executed) even in over-utilized systems, since the set of eligible task instances (called wait set) is only refilled once all the task instances in the wait set are executed. The multithreaded executor extends this mechanism to multiple threads that manage the wait set collaboratively. While intuitively this extension preserves the starvation-free property, and analyses for the multithreaded executor even build upon this assumption, the multithreaded executor has not been shown to be starvation-free.In this work, we examine the mechanism of the multithreaded executor in ROS 2 and demonstrate that it is prone to starvation, i.e., some tasks may never be executed even in under-utilized systems. This indicates risks for multithreaded executors in the current ROS 2 design and further leads to counterexamples to the state-of-the-art response-time analyses by Jiang et al. (RTSS 2022) and Sobhani et al. (RTAS 2023). We propose a minimal change in the software architecture of the ROS 2 multithreaded executor to enable starvation- and deadlock-free behavior. We empirically test that we prevent starvation in concrete ROS 2 system configurations, and show that our solution incurs a negligible overhead using the autoware reference benchmark. Moreover, we prove that our solution is starvation- and deadlock-free using formal proofs and model checking.","PeriodicalId":13251,"journal":{"name":"IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems","volume":"43 11","pages":"3588-3599"},"PeriodicalIF":2.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10745787","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Efficient Discovery of Actual Causality Using Abstraction Refinement","authors":"Arshia Rafieioskouei;Borzoo Bonakdarpour","doi":"10.1109/TCAD.2024.3448299","DOIUrl":"https://doi.org/10.1109/TCAD.2024.3448299","url":null,"abstract":"Causality is the relationship where one event contributes to the production of another, with the cause being partly responsible for the effect and the effect partly dependent on the cause. In this article, we propose a novel and effective method to formally reason about the causal effect of events in engineered systems, with application for finding the root-cause of safety violations in embedded and cyber-physical systems. We are motivated by the notion of actual causality by Halpern and Pearl, which focuses on the causal effect of particular events rather than type-level causality, which attempts to make general statements about scientific and natural phenomena. Our first contribution is formulating discovery of actual causality in computing systems modeled by transition systems as an satisfiability modulo theory solving problem. Since datasets for causality analysis tend to be large, in order to tackle the scalability problem of automated formal reasoning, our second contribution is a novel technique based on abstraction refinement that allows identifying for actual causes within smaller abstract causal models. We demonstrate the effectiveness of our approach (by several orders of magnitude) using three case studies to find the actual cause of violations of safety in 1) a neural network controller for a mountain car; 2) a controller for a Lunar Lander obtained by reinforcement learning; and 3) an MPC controller for an F-16 autopilot simulator.","PeriodicalId":13251,"journal":{"name":"IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems","volume":"43 11","pages":"4274-4285"},"PeriodicalIF":2.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142636466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hyper Parametric Timed CTL","authors":"Masaki Waga;Étienne André","doi":"10.1109/TCAD.2024.3443704","DOIUrl":"https://doi.org/10.1109/TCAD.2024.3443704","url":null,"abstract":"Hyperproperties enable simultaneous reasoning about multiple execution traces of a system and are useful to reason about noninterference, opacity, robustness, fairness, observational determinism, etc. We introduce hyper parametric timed computation tree logic (HyperPTCTL), extending hyperlogics with timing reasoning and, notably, parameters to express unknown values. We mainly consider its nest-free fragment, where the temporal operators cannot be nested. However, we allow extensions that enable counting actions and comparing the duration since the most recent occurrence of specific actions. We show that our nest-free fragment with this extension is sufficiently expressive to encode the properties, e.g., opacity, (un)fairness, or robust observational (non)determinism. We propose semi-algorithms for the model checking and synthesis of parametric timed automata (TAs) (an extension of TAs with timing parameters) against this nest-free fragment with the extension via reduction to the PTCTL model checking and synthesis. While the general model checking (and thus synthesis) problem is undecidable, we show that a large part of our extended (yet nest-free) fragment is decidable, provided the parameters only appear in the property, not in the model. We also exhibit additional decidable fragments where the parameters within the model are allowed. We implemented our semi-algorithms on the top of the IMITATOR model checker and performed experiments. Our implementation supports most of the nest-free fragments (beyond the decidable classes). The experimental results highlight our method’s practical relevance.","PeriodicalId":13251,"journal":{"name":"IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems","volume":"43 11","pages":"4286-4297"},"PeriodicalIF":2.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142636468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Habeeb;Deepak D’Souza;Kamal Lodaya;Pavithra Prabhakar
{"title":"Interval Image Abstraction for Verification of Camera-Based Autonomous Systems","authors":"P. Habeeb;Deepak D’Souza;Kamal Lodaya;Pavithra Prabhakar","doi":"10.1109/TCAD.2024.3448306","DOIUrl":"https://doi.org/10.1109/TCAD.2024.3448306","url":null,"abstract":"We propose an abstraction-refinement-based algorithm for the problem of verifying the safety of a camera-based autonomous system in a synthetic 3D-scene, based on the notion of interval images. An interval image is an abstract data structure that represents a set of images in a 3D-scene. We give a computer graphics style rendering algorithm to efficiently compute interval images from a given region. Our proposed abstraction-refinement algorithm leverages recent abstract interpretation tools for neural networks. We have implemented and evaluated the proposed technique on complex 3D-scenes, demonstrating its effectiveness and scalability in comparison with earlier techniques.","PeriodicalId":13251,"journal":{"name":"IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems","volume":"43 11","pages":"4310-4321"},"PeriodicalIF":2.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142636559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Navid Hashemi;Lars Lindemann;Jyotirmoy V. Deshmukh
{"title":"Statistical Reachability Analysis of Stochastic Cyber-Physical Systems Under Distribution Shift","authors":"Navid Hashemi;Lars Lindemann;Jyotirmoy V. Deshmukh","doi":"10.1109/TCAD.2024.3438072","DOIUrl":"https://doi.org/10.1109/TCAD.2024.3438072","url":null,"abstract":"Reachability analysis is a popular method to give safety guarantees for stochastic cyber-physical systems (SCPSs) that takes in a symbolic description of the system dynamics and uses set-propagation methods to compute an overapproximation of the set of reachable states over a bounded time horizon. In this article, we investigate the problem of performing reachability analysis for an SCPS that does not have a symbolic description of the dynamics, but instead is described using a digital twin model that can be simulated to generate system trajectories. An important challenge is that the simulator implicitly models a probability distribution over the set of trajectories of the SCPS; however, it is typical to have a sim2real gap, i.e., the actual distribution of the trajectories in a deployment setting may be shifted from the distribution assumed by the simulator. We thus propose a statistical reachability analysis technique that, given a user-provided threshold \u0000<inline-formula> <tex-math>$1-epsilon $ </tex-math></inline-formula>\u0000, provides a set that guarantees that any trajectory during deployment lies in this set with probability not smaller than this threshold. Our method is based on three main steps: 1) learning a deterministic surrogate model from sampled trajectories; 2) conducting reachability analysis over the surrogate model; and 3) employing robust conformal inference (CI) using an additional set of sampled trajectories to quantify the surrogate model’s distribution shift with respect to the deployed SCPS. To counter conservatism in reachable sets, we propose a novel method to train surrogate models that minimizes a quantile loss term (instead of the usual mean squared loss), and a new method that provides tighter guarantees using CI using a normalized surrogate error. We demonstrate the effectiveness of our technique on various case studies.","PeriodicalId":13251,"journal":{"name":"IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems","volume":"43 11","pages":"4250-4261"},"PeriodicalIF":2.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142636374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Approximate Conformance Checking for Closed-Loop Systems With Neural Network Controllers","authors":"P. Habeeb;Lipsy Gupta;Pavithra Prabhakar","doi":"10.1109/TCAD.2024.3445813","DOIUrl":"https://doi.org/10.1109/TCAD.2024.3445813","url":null,"abstract":"In this article, we consider the problem of checking approximate conformance of closed-loop systems with the same plant but different neural network (NN) controllers. First, we introduce a notion of approximate conformance on NNs, which allows us to quantify semantically the deviations in closed-loop system behaviors with different NN controllers. Next, we consider the problem of computationally checking this notion of approximate conformance on two NNs. We reduce this problem to that of reachability analysis on a combined NN, thereby, enabling the use of existing NN verification tools for conformance checking. Our experimental results on an autonomous rocket landing system demonstrate the feasibility of checking approximate conformance on different NNs trained for the same dynamics, as well as the practical semantic closeness exhibited by the corresponding closed-loop systems.","PeriodicalId":13251,"journal":{"name":"IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems","volume":"43 11","pages":"4322-4333"},"PeriodicalIF":2.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142636560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"CaBaFL: Asynchronous Federated Learning via Hierarchical Cache and Feature Balance","authors":"Zeke Xia;Ming Hu;Dengke Yan;Xiaofei Xie;Tianlin Li;Anran Li;Junlong Zhou;Mingsong Chen","doi":"10.1109/TCAD.2024.3446881","DOIUrl":"https://doi.org/10.1109/TCAD.2024.3446881","url":null,"abstract":"Federated learning (FL) as a promising distributed machine learning paradigm has been widely adopted in Artificial Intelligence of Things (AIoT) applications. However, the efficiency and inference capability of FL is seriously limited due to the presence of stragglers and data imbalance across massive AIoT devices, respectively. To address the above challenges, we present a novel asynchronous FL approach named CaBaFL, which includes a hierarchical cache-based aggregation mechanism and a feature balance-guided device selection strategy. CaBaFL maintains multiple intermediate models simultaneously for local training. The hierarchical cache-based aggregation mechanism enables each intermediate model to be trained on multiple devices to align the training time and mitigate the straggler issue. In specific, each intermediate model is stored in a low-level cache for local training and when it is trained by sufficient local devices, it will be stored in a high-level cache for aggregation. To address the problem of imbalanced data, the feature balance-guided device selection strategy in CaBaFL adopts the activation distribution as a metric, which enables each intermediate model to be trained across devices with totally balanced data distributions before aggregation. Experimental results show that compared to the state-of-the-art FL methods, CaBaFL achieves up to 9.26X training acceleration and 19.71% accuracy improvements.","PeriodicalId":13251,"journal":{"name":"IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems","volume":"43 11","pages":"4057-4068"},"PeriodicalIF":2.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Backdoor Attacks on Safe Reinforcement Learning-Enabled Cyber–Physical Systems","authors":"Shixiong Jiang;Mengyu Liu;Fanxin Kong","doi":"10.1109/TCAD.2024.3447468","DOIUrl":"https://doi.org/10.1109/TCAD.2024.3447468","url":null,"abstract":"Safe reinforcement learning (RL) aims to derive a control policy that navigates a safety-critical system while avoiding unsafe explorations and adhering to safety constraints. While safe RL has been extensively studied, its vulnerabilities during the policy training have barely been explored in an adversarial setting. This article bridges this gap and investigates the training time vulnerability of formal language-guided safe RL. Such vulnerability allows a malicious adversary to inject backdoor behavior into the learned control policy. First, we formally define backdoor attacks for safe RL and divide them into active and passive ones depending on whether to manipulate the observation. Second, we propose two novel algorithms to synthesize the two kinds of attacks, respectively. Both algorithms generate backdoor behaviors that may go unnoticed after deployment but can be triggered when specific states are reached, leading to safety violations. Finally, we conduct both theoretical analysis and extensive experiments to show the effectiveness and stealthiness of our methods.","PeriodicalId":13251,"journal":{"name":"IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems","volume":"43 11","pages":"4093-4104"},"PeriodicalIF":2.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bank on Compute-Near-Memory: Design Space Exploration of Processing-Near-Bank Architectures","authors":"Rafael Medina;Giovanni Ansaloni;Marina Zapater;Alexandre Levisse;Saeideh Alinezhad Chamazcoti;Timon Evenblij;Dwaipayan Biswas;Francky Catthoor;David Atienza","doi":"10.1109/TCAD.2024.3442989","DOIUrl":"https://doi.org/10.1109/TCAD.2024.3442989","url":null,"abstract":"Near-DRAM computing strategies advocate for providing computational capabilities close to where data is stored. Although this paradigm can effectively address the memory-to-processor communication bottleneck, it also presents new challenges: The strict resource constraints in the memory periphery demand careful tailoring of architectural elements. We herein propose a novel framework and methodology to explore compute-near-memory designs that interface to DRAM memory banks, demonstrating the area, energy, and performance tradeoffs subject to the architectural configuration. We exemplify this methodology by conducting two studies on compute-near-bank designs: 1) analyzing the interaction between control and data resources, and 2) exploring the integration of processing units with different DRAM standards. According to our study, the optimal size ratios between instruction and data capacity vary from \u0000<inline-formula> <tex-math>$2times $ </tex-math></inline-formula>\u0000 to \u0000<inline-formula> <tex-math>$4times $ </tex-math></inline-formula>\u0000 across benchmarks from representative application domains. The retrieved Pareto-optimal solutions from our framework improve state-of-the-art designs, e.g., achieving a 50% performance increase on matrix operations with 15% energy overhead relative to the FIMDRAM design. In addition, the exploration of DRAM shows the interplay between available internal bandwidth, performance, and area overhead. For example, a threefold increase in bandwidth rises performance by 47% across workloads at a 34% extra area cost.","PeriodicalId":13251,"journal":{"name":"IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems","volume":"43 11","pages":"4117-4129"},"PeriodicalIF":2.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}