Current Organizations / Institutes

The organizations/institutes from the scholar's latest article


Mirabela-Melinda Medvei has a total of 16 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Semi-supervised zero-knowledge federated learning for intelligent transportation systems

    by Mirabela-Melinda Medvei, Miruna-Mihaela Modiga, Iuliani Aciobăniței, Nicolae Ţăpuş

    Privacy-preserving machine learning in Vehicular Ad Hoc Networks (VANETs) must address sensitive on-board data, limited ground-truth annotations, and verifiable model-update integrity. This paper proposes ZK-FL, a decentralized federated learning framework for Intelligent Transportation Systems (ITS) scene classification that combines semi-supervised pseudo-labeling, zk-SNARK-based update validation, and Hyperledger Besu blockchain auditability. Vehicles train local models, quantize the resulting updates, and generate zero-knowledge proofs demonstrating that distributed update probes satisfy a predefined norm-boundedness constraint. Road-Side Units (RSUs) verify the proofs before aggregation and anchor the corresponding audit metadata on-chain. The framework is evaluated on the BDD100K and Mapillary Vistas v2 datasets under multiple non-IID data distributions and five aggregation methods: FedAvg, Norm Clipping, Median, Trimmed Mean, and Krum. Since Mapillary Vistas does not provide scene-level annotations, two scene-label generation strategies, including a semi-supervised pseudo-labeling approach, are introduced. Experimental results demonstrate effective scene classification, verifiable update integrity, and practical proof-generation and verification, supporting the feasibility of privacy-preserving federated learning for ITS.

  • Open Access

    ITS-Vision: Autonomous Vehicles as Mobile Surveillance Nodes in Intelligent Transportation Systems—A Conceptual Framework and Proof-of-Concept Prototype

    by Mirabela-Melinda Medvei, Denis Georgian Gurău, Mihai Coca

    Crime surveillance in urban environments faces increasing challenges due to dynamic conditions and the demand for real-time monitoring. This paper investigates the use of video data from autonomous vehicles to enhance situational awareness in public spaces through deep learning models optimized for edge processing. High-resolution vehicle-mounted cameras serve as mobile surveillance units capable of real-time object detection, human action recognition, and anomaly detection, bridging the gap between autonomous mobility and urban monitoring. Building on this vision, we introduce ITS-Vision, a generic framework that operationalizes these use cases, enabling autonomous vehicles to function as mobile, context-aware sensing platforms. To validate this approach, we develop prototypes for key ITS-Vision components: a fight detection module using a fine-tuned X3D model, suspect identification via MediaPipe for detection combined with FaceNet for embedding extraction, and a dangerous items detection module using a fine-tuned YOLOv11n model. Due to the limited availability of real-world autonomous vehicle video datasets, experiments were conducted in controlled laboratory environments, demonstrating the feasibility of the proposed architecture and algorithms under simulated conditions. Future work will focus on collecting dedicated datasets and advancing the models toward deployment in real urban scenarios.

  • Open Access

    RoRED: A Romanian Relation Extraction Dataset

    by George-Andrei Dima, Ilie Cosmin Bilțan, Mirabela-Melinda Medvei, Luciana Morogan

    Relation extraction is an important task for structuring information from unstructured text. However, the Romanian language still lacks dedicated datasets and benchmarks for this task. To address this gap, we introduce RoRED, a Romanian relation extraction dataset built by combining two complementary data construction strategies: translating existing high-quality English resources and applying distant supervision to native Romanian Wikipedia data. We leverage a powerful open-source large language model to automatically translate English examples into Romanian. For the native subset, we align Romanian Wikipedia entities with Wikidata relations to obtain naturally occurring Romanian examples. To better reflect real-world relation extraction scenarios, we also introduce synthetic negative examples generated using existing Romanian named entity recognition models. Finally, we validate the dataset by fine-tuning and evaluating multiple baseline models. Our strongest model, LUKE-RoRED, achieves a macro-F1 score of 0.8744 on the RoRED test set, demonstrating that the dataset can support relation extraction for Romanian. Overall, RoRED provides a strong first native benchmark for Romanian relation extraction.

  • Task Load Balancing in the Vehicular Edge Computing Layer Using Traffic Prediction

    by Mirabela Medvei, Ștefania Ștefănescu, George-Andrei Dima

  • Open Access

    SSTIR: Harnessing Multimodal Large-Language Models for Semi-Structured Traffic Incident Reports

    by Mirabela-Melinda Medvei, George-Andrei Dima, Stefania Stefanescu

  • Open Access

    DeepSIGNAL-ITS—Deep Learning Signal Intelligence for Adaptive Traffic Signal Control in Intelligent Transportation Systems

    by Mirabela Melinda Medvei, Alin-Viorel Bordei, Ștefania Loredana Niță, Nicolae Țăpuș

    Urban traffic congestion remains a major contributor to vehicle emissions and travel inefficiency, prompting the need for adaptive and intelligent traffic management systems. In response, we introduce DeepSIGNAL-ITS (Deep Learning Signal Intelligence for Adaptive Lights in Intelligent Transportation Systems), a unified framework that leverages real-time traffic perception and learning-based control to optimize signal timing and reduce congestion. The system integrates vehicle detection via the YOLOv8 architecture at roadside units (RSUs) and manages signal control using Proximal Policy Optimization (PPO), guided by global traffic indicators such as accumulated vehicle waiting time. Secure communication between RSUs and cloud infrastructure is ensured through Transport Layer Security (TLS)-encrypted data exchange. We validate the framework through extensive simulations in SUMO across diverse urban settings. Simulation results show an average 30.20% reduction in vehicle waiting time at signalized intersections compared to baseline fixed-time configurations derived from OpenStreetMap (OSM). Furthermore, emissions assessed via the HBEFA-based model in SUMO reveal measurable reductions across pollutant categories, underscoring the framework’s dual potential to improve both traffic efficiency and environmental sustainability in simulated urban environments.


  • Open Access

    RESFIT: A Reputation and Security Monitoring Platform for IoT Applications

    by Ștefan-Ciprian Arseni, Bogdan-Cosmin Chifor, Mihai Coca, Mirabela Medvei, Ion Bica, Ioana Matei

    The fast-paced adoption of smart devices has changed the Internet of Things (IoT) landscape, leading to the growth of smart environments and inclusion in many aspects of our society. In IoT applications, data collected from sensors and mobile devices are aggregated, processed, and analyzed to extract useful information and develop intelligent services. If the collected data is not trustworthy due to the damage or malicious input of some sensors, the quality of the service will be impacted. For reliable data collection and mining, it is mandatory to define robust security and trust models, suitable for the IoT application context. In this paper, we propose RESFIT, a platform that implements a reputation-based trust mechanism and an advanced application level firewall to cope with the above mentioned issues. Having a gateway-centric architecture, the proposed platform ensures minimal resource consumption at the node layer, and an integrated overview and control of the system state, through the cloud component and smartphone management application.