Real-Time Hand Gesture Recognition (HGR) has emerged as a key model of modern Human Computer Interaction (HCI) technologies, enabling touchless and intuitive interactive experiences for a wide range of HCI applications, from assistive technology, virtual and augmented reality to industrial production lines. Although AI and DL open up important opportunities, there are practical challenges to developing and deploying real-time HGR systems that are strong to issues such as computational complexity, variations in the environment, and latency. This survey reviews the state-of-the-art in real-time HGR, including recent work in and algorithmic approaches for various sensor modalities and different stages of the processing pipeline, including detection, tracking, and spatial-temporal classification, using monocular RGB cameras and multi-modal depth sensing systems. In addition, we cover applications such as sign language recognition, healthcare hygiene systems, automotive user interfaces, and human-robot collaboration (HRC), and challenges such as occlusion invariance, light variability, performance versus portability trade-offs, constraints imposed by edge-device deployment, and potential research avenues for multimodal artificial intelligence systems of the future.
After the optimal parameters of additive quaternary codes of dimension k<=3 have been determined in [1], there was some activity to settle the next case of dimension k=3.5 [2,3]. Here we complete dimensions k=3.5 and k=4. We also solve the problem of the optimal parameters of additive quaternary codes of arbitrary dimension when assuming a sufficiently large minimum distance.
This paper proposes a novel image steganographic method based on discrete Rademacher functions combined with Least Significant Bit (LSB) embedding. Unlike conventional sequential LSB techniques, which modify pixel values in a deterministic scan order, the proposed approach introduces a mathematically structured selection mechanism that governs both spatial embedding locations and, in the case of color images, channel selection. The performance of the proposed method is evaluated using standard benchmark images, including grayscale and color versions of the Lena, Tank, and Pepper datasets at a resolution of 512 × 512 pixels. The quality of stego-images is measured using Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity Index (SSIM), ensuring both pixel-level accuracy and perceptual similarity assessment. Experimental results demonstrate that the proposed method maintains PSNR values above conventional acceptability thresholds and SSIM values close to unity across various embedding rates. Comparative analysis with classical sequential LSB embedding confirms that the proposed approach achieves comparable or improved imperceptibility, particularly in color images due to distributed channel embedding. The results indicate that Rademacher-based LSB steganography offers a favorable trade-off between embedding capacity, visual quality, and security.
This article presents a methodology for the analysis and classification of communication protocols and data stream management systems used in machine-to-machine (M2M) environments. The focus is placed on non-functional characteristics such as latency, reliability, scalability, security, and message ordering, and their relevance in protocol selection across different functional domains. A comparative evaluation of established protocols - including MQTT, HTTP/1.1-3, Kafka, Pulsar, RabbitMQ, AMQP, and CoAP - is conducted based on objective criteria and existing literature. Building on this foundation, hybrid architectures are proposed that combine multiple technologies according to the criticality and technical requirements of specific scenarios. The paper offers structured recommendations for communication strategies in M2M contexts, with empirical validation planned as the subject of future work.
Minimal codes are linear codes where all non-zero codewords are minimal, i.e., whose support is not properly contained in the support of another codeword. The minimum possible length of such a $k$-dimensional linear code over $\mathbb{F}_q$ is denoted by $m(k,q)$. Here we determine $m(7,2)$, $m(8,2)$, and $m(9,2)$, as well as full classifications of all codes attaining $m(k,2)$ for $k\le 7$ and those attaining $m(9,2)$. We give improved upper bounds for $m(k,2)$ for all $10\le k\le 17$. It turns out that in many cases the attaining extremal codes have the property that the weights of all codewords are divisible by some constant $\Delta>1$. So, here we study the minimum lengths of minimal codes where we additionally assume that the weights of the codewords are divisible by $\Delta$. As a byproduct we also give a few binary linear codes improving the best known lower bound for the minimum distance.
