arXiv subjects

Sushanta Das

Publications and source records attributed to Sushanta Das.

6 recordsLinked to original sources

arXiv2026

PRISM: An Agentic Multi-Model Architecture for Proactive Safety in Autonomous Transportation Systems

Autonomous and intelligent transportation systems operate in complex urban environments where safety depends on interactions among vehicle behavior, environmental conditions, and vulnerable road users (VRUs) such as pedestrians and cyclists. Most advanced driver assistance systems (ADAS) employ reactive mechanisms that activate only after hazards have emerged, a critical limitation underscored by rising VRU fatalities in the United States. This study introduces PRISM (Proactive Risk Intelligence and Safety Management), an agentic multi-model safety architecture that transitions from reactive crash avoidance to proactive, continuous risk management. PRISM employs inverse crash-probability modeling to convert binary crash classifiers into dynamic, interpretable safety scores. Three specialized models addressing trajectory kinematics, environmental risk, and VRU interaction operate concurrently, coordinated by a reasoning layer incorporating reinforcement learning, contextual memory, and feature-level attribution. The system provides graduated safety interventions across four tiers, from silent monitoring to emergency alerts. Unlike rule-based systems with static thresholds, PRISM dynamically adjusts safety parameters in real time. Validated across 1,296 scenarios from three naturalistic driving datasets without dataset-specific retraining, the system yielded a mean safety score of 68 out of 100, classified 77.6% of scenarios as advisory, and flagged a near-miss rate of 3.8%, with 11% of scenarios escalating to intervention or emergency response. Feature attribution consistently identified trajectory risk and VRU proximity as primary safety factors. PRISM provides a unified, interpretable framework for proactive transportation safety with emphasis on VRU risk reduction in dense urban environments.

cs.MA↗

arXiv2026

Real-Time Driver Safety Scoring Through Inverse Crash Probability Modeling

Road crashes remain a leading cause of preventable fatalities. Existing prediction models predominantly produce binary outcomes, which offer limited actionable insights for realtime driver feedback. These approaches often lack continuous risk quantification, interpretability, and explicit consideration of vulnerable road users (VRUs), such as pedestrians and cyclists. This research introduces SafeDriver-IQ, a framework that transforms binary crash classifiers into continuous 0-100 safety scores by combining national crash statistics with naturalistic driving data from autonomous vehicles. The framework fuses National Highway Traffic Safety Administration (NHTSA) crash records with Waymo Open Motion Dataset scenarios, engineers domain-informed features, and incorporates a calibration layer grounded in transportation safety literature. Evaluation across 15 complementary analyses indicates that the framework reliably differentiates high-risk from low-risk driving conditions with strong discriminative performance. Findings further reveal that 87% of crashes involve multiple co-occurring risk factors, with non-linear compounding effects that increase the risk to 4.5x baseline. SafeDriver-IQ delivers proactive, explainable safety intelligence relevant to advanced driver-assistance systems (ADAS), fleet management, and urban infrastructure planning. Beyond the specific application, the inverse modeling paradigm is domain-agnostic. Any binary risk classifier can be converted into a continuous, explainable safety-scoring system using the same pipeline without retraining. This framework shifts the focus from reactive crash counting to real-time risk prevention.

cs.LG↗

arXiv2025

PBPU Elastomer Network Architecture Determination via Corresponding States Analysis of Mechanical Behavior

In this work we examine the effect of R=[NCO]/[OH] in the R=<1 regime, on the resultant structural topology of polybutadiene polyurethane (PBPU) elastomer networks based on hydroxy-terminated polybutadiene (HTPB). We employ stress-elongation behavior and its modeling, as a tool. We examine this property via a combination of our model for the finite chain phantom networks incorporating the HTPB structural information, with the slip-tube model from the literature, suitably modified phenomenologically. We implement a further normalized Mooney-Rivlin (MR) representation (corresponding deformation states plots), to remove any magnitude bias on the model parameters. The now revealed curvatures of all the MR plots, in turn, reveals the non-correlation between the chain size and crosslink density. This discrepancy occurs due to the R-dependent majority presence of network defects due to sol effects (as obtained from swelling experiments) and non-load bearing pendant branches on the load-bearing network chains.

cond-mat.soft↗

arXiv2024

Defining Ideal Phantom Polymer Networks

Elastomers are modeled as networks with $\phi $-functional junctions containing $N$ ideal, $n$-segment, freely jointed chains (FJCs) per unit volume (p.u.v.). Our compact model of the exact FJC length probability density (Treloar, 1975), accurately yields their exact distribution moments (Flory, 1969). The governing geometry of fluctuations of $N_X = 2N/\phi$ junctions p.u.v., parametrically maps their $\lambda$(elongation ratio)-dependent distribution to an equivalent FJC consisting of $n_{f\phi} = (n/\phi)(1-\Lambda)$ segments, where $\Lambda = (1/3n)(\lambda^2 + 2/\lambda))$. The resulting elastic pre-factor, $N_{\text{eff}}kT = (N - \eta N_X)kT$, with junction effectiveness $\eta = \phi(1-\Lambda)/(\phi-\Lambda)$, defines ideal phantom networks

cond-mat.soft↗

arXiv2018

Regulatory Options and Technical Challenges for the 5.9 GHz Spectrum: Survey and Analysis

In 1999, the Federal Communications Commission (FCC) allocated 75 MHz in the 5.9 GHz ITS Band (5850-5925 MHz) for use by Dedicated Short Range Communications (DSRC) to facilitate information transfer between equipped vehicles and roadside systems. This allocation for DSRC in the ITS band has been a co-primary allocation while the band is shared with the Fixed Satellite Service (FSS), fixed microwave service, amateur radio services and other Federal users authorized by the National Telecommunications and Information Administration (NTIA). In recent time, Cellular V2X (C-V2X), introduced in 3GPP Release 14 LTE standard, has received significant attention due to its perceived ability to deliver superior performance with respect to vehicular safety applications. There is a strong momentum in the industry for C-V2X to be considered as a viable alternative to DSRC and accordingly, to operate in the ITS spectrum. In another recent notice, the FCC is soliciting input for a proposed rulemaking to open up more bandwidth for unlicensed Wi-Fi devices, mainly based on the 802.11ac standard. The FCC plans to work with the Department of Transportation (DoT), and the automotive and communications industries to evaluate potential sharing techniques in the ITS band between DSRC and Wi-Fi devices. This paper analyzes the expected scenarios that might emerge from FCC and the National Highway Traffic Safety Administration (NHTSA) regulation options and identifies the technical challenge associated with each scenario. We also provide a literature survey and find that many of resulting technical challenges remain open research problems that need to be addressed. We conclude that the most challenging issue is related to the interoperability between DSRC and C-V2X in the 5.9 GHz band and the detection and avoidance of harmful adjacent and co-channel interference.

eess.SP↗

arXiv2018

Multiple Access in Cellular V2X: Performance Analysis in Highly Congested Vehicular Networks

Vehicle-to-everything (V2X) communication enables vehicles, roadside vulnerable users, and infrastructure facilities to communicate in an ad-hoc fashion. Cellular V2X (C-V2X), which was introduced in the 3rd generation partnership project (3GPP) release 14 standard, has recently received significant attention due to its perceived ability to address the scalability and reliability requirements of vehicular safety applications. In this paper, we provide a comprehensive study of the resource allocation of the C-V2X multiple access mechanism for high-density vehicular networks, as it can strongly impact the key performance indicators such as latency and packet delivery rate. Phenomena that can affect the communication performance are investigated and a detailed analysis of the cases that can cause possible performance degradation or system limitations, is provided. The results indicate that a unified system configuration may be necessary for all vehicles, as it is mandated for IEEE 802.11p, in order to obtain the optimum performance. In the end, we show the inter-dependence of different parameters on the resource allocation procedure with the aid of our high fidelity simulator.

cs.NI↗