Bucharest
On the use of chaotic dynamics for mobile network design and analysis: towards a trace data generator
Rosalie, Martin, Chaumette, Serge
In this context, defining and analysing their mobility is particularly important. A mobility model describes the behaviour of an entity considering its capacities, possible moves and speed. The mobility models are described either analytically at the individual level, or by the interactions between the parts of the system (between UAVs, UAVs and planes, UAVs and points to survey, etc.). The resulting behaviours described with these simple rules can induce the emergence of a global intelligent behaviour. Inversely, from the resulting behaviour of such a swarm, these initial simple rules are hard to discover.
Smart Home Environment Modelled with a Multi-Agent System
Rasras, Mohammad, Marin, Iuliana, Radu, Serban
A smart home can be considered a place of residence that enables the management of appliances and systems to help with day-to-day life by automated technology. In the current paper is described a prototype that simulates a contextaware environment, developed in a designed smart home. The smart home environment has been simulated using three agents and five locations in a house. The context-aware agents behave based on predefined rules designed for daily activities. Our proposal aims to reduce operational cost of running devices. In the future, monitors of health aspects belonging to home residents will sustain their healthy life daily. Keywords: smart home, multi-agent system, K-Nearest Neighbor algorithm, K-Means Clustering algorithm 1. Introduction Smart home, also known as an intelligent house, incorporates special devices that manage house features.
FedRight: An Effective Model Copyright Protection for Federated Learning
Chen, Jinyin, Li, Mingjun, Li, Mingjun, Zheng, Haibin
Federated learning (FL), an effective distributed machine learning framework, implements model training and meanwhile protects local data privacy. It has been applied to a broad variety of practice areas due to its great performance and appreciable profits. Who owns the model, and how to protect the copyright has become a real problem. Intuitively, the existing property rights protection methods in centralized scenarios (e.g., watermark embedding and model fingerprints) are possible solutions for FL. But they are still challenged by the distributed nature of FL in aspects of the no data sharing, parameter aggregation, and federated training settings. For the first time, we formalize the problem of copyright protection for FL, and propose FedRight to protect model copyright based on model fingerprints, i.e., extracting model features by generating adversarial examples as model fingerprints. FedRight outperforms previous works in four key aspects: (i) Validity: it extracts model features to generate transferable fingerprints to train a detector to verify the copyright of the model. (ii) Fidelity: it is with imperceptible impact on the federated training, thus promising good main task performance. (iii) Robustness: it is empirically robust against malicious attacks on copyright protection, i.e., fine-tuning, model pruning, and adaptive attacks. (iv) Black-box: it is valid in the black-box forensic scenario where only application programming interface calls to the model are available. Extensive evaluations across 3 datasets and 9 model structures demonstrate FedRight's superior fidelity, validity, and robustness.
Traffic4cast at NeurIPS 2022 -- Predict Dynamics along Graph Edges from Sparse Node Data: Whole City Traffic and ETA from Stationary Vehicle Detectors
Neun, Moritz, Eichenberger, Christian, Martin, Henry, Spanring, Markus, Siripurapu, Rahul, Springer, Daniel, Deng, Leyan, Wu, Chenwang, Lian, Defu, Zhou, Min, Lumiste, Martin, Ilie, Andrei, Wu, Xinhua, Lyu, Cheng, Lu, Qing-Long, Mahajan, Vishal, Lu, Yichao, Li, Jiezhang, Li, Junjun, Gong, Yue-Jiao, Grötschla, Florian, Mathys, Joël, Wei, Ye, Haitao, He, Fang, Hui, Malm, Kevin, Tang, Fei, Kopp, Michael, Kreil, David, Hochreiter, Sepp
The global trends of urbanization and increased personal mobility force us to rethink the way we live and use urban space. The Traffic4cast competition series tackles this problem in a data-driven way, advancing the latest methods in machine learning for modeling complex spatial systems over time. In this edition, our dynamic road graph data combine information from road maps, $10^{12}$ probe data points, and stationary vehicle detectors in three cities over the span of two years. While stationary vehicle detectors are the most accurate way to capture traffic volume, they are only available in few locations. Traffic4cast 2022 explores models that have the ability to generalize loosely related temporal vertex data on just a few nodes to predict dynamic future traffic states on the edges of the entire road graph. In the core challenge, participants are invited to predict the likelihoods of three congestion classes derived from the speed levels in the GPS data for the entire road graph in three cities 15 min into the future. We only provide vehicle count data from spatially sparse stationary vehicle detectors in these three cities as model input for this task. The data are aggregated in 15 min time bins for one hour prior to the prediction time. For the extended challenge, participants are tasked to predict the average travel times on super-segments 15 min into the future - super-segments are longer sequences of road segments in the graph. The competition results provide an important advance in the prediction of complex city-wide traffic states just from publicly available sparse vehicle data and without the need for large amounts of real-time floating vehicle data.
Romania PM unveils AI 'adviser' to tell him what people think in real time
Romania's prime minister has presented his "new honorary adviser" – an artificial intelligence assistant named "Ion" that Nicolae Ciuca hailed as the first of its type. Developed by Romanian researchers, Ion's main task will be to scan social networks to inform the government "in real time of Romanians' proposals and wishes", Ciuca said on Wednesday. The liberal minister said the latest member of his entourage – a mirror-like structure with beeping interface – marked "an international first", describing Ion as "the first government adviser to use artificial intelligence". "Hi, you gave me life and my role is now to represent you, like a mirror," Ion's calm voice said at the launch. "What should I know about Romania?" Ion "will use technology and artificial intelligence to capture opinions in society" using "data publicly available on social networks", according to a government document detailing the project.
CONTAIN: A Community-based Algorithm for Network Immunization
Coban, Özgur, Truică, Ciprian-Octavian, Apostol, Elena-Simona
The adoption of advanced digital technologies has transformed and evolved social media, which in turn enhanced the connectivity and awareness of our society. Along with these advancements, digitalization also created a favorable environment for the diffusion of misinformation [9, 22, 27, 26] (i.e., the unintentional spread of false information), disinformation (i.e., the intentional spread of false information), and hate speech (i.e., the intentional spread of malicious content expressing hate and violence). Conversely, research in network analysis has advanced, proposing various ideas for network immunization strategies [30, 4, 15, 31, 16]. Given a social network, consider how the content produced from a node spreads in the network. This is known as information diffusion, and it has shown to be a crucial field of research in network analysis - as an example, how the political ideas of a politician influence a social network [1].
Mapping Wordnets on the Fly with Permanent Sense Keys
Most of the major databases on the semantic web have links to Princeton WordNet (PWN) synonym set (synset) identifiers, which differ for each PWN release, and are thus incompatible between versions. On the other hand, both PWN and the more recent Open English Wordnet (OEWN) provide permanent word sense identifiers (the sense keys), which can solve this interoperability problem. We present an algorithm that runs in linear time, to automatically derive a synset mapping between any pair of Wordnet versions that use PWN sense keys. This allows to update old WordNet links, and seamlessly interoperate with newer English Wordnet versions for which no prior mapping exists. By applying the proposed algorithm on the fly, at load time, we combine the Open Multilingual Wordnet (OMW 1.4, which uses old PWN 3.0 identifiers) with OEWN Edition 2021, and obtain almost perfect precision and recall. We compare the results of our approach using respectively synset offsets, versus the Collaborative InterLingual Index (CILI version 1.0) as synset identifiers, and find that the synset offsets perform better than CILI 1.0 in all cases, except a few ties.
RAMM: Retrieval-augmented Biomedical Visual Question Answering with Multi-modal Pre-training
Yuan, Zheng, Jin, Qiao, Tan, Chuanqi, Zhao, Zhengyun, Yuan, Hongyi, Huang, Fei, Huang, Songfang
Vision-and-language multi-modal pretraining and fine-tuning have shown great success in visual question answering (VQA). Compared to general domain VQA, the performance of biomedical VQA suffers from limited data. In this paper, we propose a retrieval-augmented pretrain-and-finetune paradigm named RAMM for biomedical VQA to overcome the data limitation issue. Specifically, we collect a new biomedical dataset named PMCPM which offers patient-based image-text pairs containing diverse patient situations from PubMed. Then, we pretrain the biomedical multi-modal model to learn visual and textual representation for image-text pairs and align these representations with image-text contrastive objective (ITC). Finally, we propose a retrieval-augmented method to better use the limited data. We propose to retrieve similar image-text pairs based on ITC from pretraining datasets and introduce a novel retrieval-attention module to fuse the representation of the image and the question with the retrieved images and texts. Experiments demonstrate that our retrieval-augmented pretrain-and-finetune paradigm obtains state-of-the-art performance on Med-VQA2019, Med-VQA2021, VQARAD, and SLAKE datasets. Further analysis shows that the proposed RAMM and PMCPM can enhance biomedical VQA performance compared with previous resources and methods. We will open-source our dataset, codes, and pretrained model.
MCWDST: a Minimum-Cost Weighted Directed Spanning Tree Algorithm for Real-Time Fake News Mitigation in Social Media
Truică, Ciprian-Octavian, Apostol, Elena-Simona, Nicolescu, Radu-Cătălin, Karras, Panagiotis
With the accelerated technology adoption by a growing number of users, social media have become the main medium for the dissemination of information on current news and events. While these new media bring several benefits (e.g., a large number of consumers reached, instant and continuous updates on one's topics of interest), they also enable the spread of harmful information in the form of fake news, and may thus polarize public discourse regarding critical topics (e.g., elections [32], vaccination [30], health hazards [24]) and threaten democratic values [35]. Because of its detrimental effects on society at large, the fake news phenomenon has been studied by scientists and practitioners alike; fake news is defined as news articles that intentionally contain verifiably false misleading information inconsistent with factual reality [2, 23, 46, 10, 4, 13, 43]. To mitigate the threat of fake news, journalists have started to manually classify news and offer websites with fact-checking mechanisms that provide a verdict regarding its veracity, such as PolitiFact (https://www.politifact.com/)
SSMTL++: Revisiting Self-Supervised Multi-Task Learning for Video Anomaly Detection
Barbalau, Antonio, Ionescu, Radu Tudor, Georgescu, Mariana-Iuliana, Dueholm, Jacob, Ramachandra, Bharathkumar, Nasrollahi, Kamal, Khan, Fahad Shahbaz, Moeslund, Thomas B., Shah, Mubarak
A self-supervised multi-task learning (SSMTL) framework for video anomaly detection was recently introduced in literature. Due to its highly accurate results, the method attracted the attention of many researchers. In this work, we revisit the self-supervised multi-task learning framework, proposing several updates to the original method. First, we study various detection methods, e.g. based on detecting high-motion regions using optical flow or background subtraction, since we believe the currently used pre-trained YOLOv3 is suboptimal, e.g. objects in motion or objects from unknown classes are never detected. Second, we modernize the 3D convolutional backbone by introducing multi-head self-attention modules, inspired by the recent success of vision transformers. As such, we alternatively introduce both 2D and 3D convolutional vision transformer (CvT) blocks. Third, in our attempt to further improve the model, we study additional self-supervised learning tasks, such as predicting segmentation maps through knowledge distillation, solving jigsaw puzzles, estimating body pose through knowledge distillation, predicting masked regions (inpainting), and adversarial learning with pseudo-anomalies. We conduct experiments to assess the performance impact of the introduced changes. Upon finding more promising configurations of the framework, dubbed SSMTL++v1 and SSMTL++v2, we extend our preliminary experiments to more data sets, demonstrating that our performance gains are consistent across all data sets. In most cases, our results on Avenue, ShanghaiTech and UBnormal raise the state-of-the-art performance bar to a new level.