Computer Science
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ISSN 1508-2806
e-ISSN: 2300-7036
Issue Date
2022
Volume
Vol. 23
Number
No. 4
Description
Journal Volume
Computer Science
Vol. 23 (2022)
Projects
Pages
Articles
FPGA-based secure and noiseless image transmission using lea and optimized bilateral filter
(Wydawnictwa AGH, 2022) Hebbale, Sunil B.; Akula, V. S. Giridhar; Baraki, Parashuram
In today's world, the transmission of secured and noiseless images is a difficult task. Therefore, effective strategies are important for securing data or secret images from attackers. Besides, denoising approaches are important for obtaining noise-free images. For this, an effective crypto-steganography method that is based on a lightweight encryption algorithm (LEA) and the modified least significant bit (MLSB) method for secured transmission is proposed. Moreover, a bilateral filter-based whale optimization algorithm (WOA) is used for image denoising. Before the image transmission, a secret image is encrypted by the LEA algorithm and embedded into the cover image using discrete wavelet transform (DWT) and MLSB techniques. After the image transmission, an extraction process is performed in order to recover the secret image. Finally, a bilateral WOA filter is used to remove the noise from the secret image. The Verilog code for the proposed model is designed and simulated in Xilinx software. Finally, the simulation results show that the proposed filtering technique results in performance that is superior to conventional bilateral and Gaussian filters in terms of the peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM).
Dynamic fuzzy model for detecting verbal violence in real time
(Wydawnictwa AGH, 2022) Campos, Obed; Pancardo, Pablo; Hernández-Nolasco, José Adán
The crime rates in Mexico have been increasing in recent years, every day, there are reports on social media and in the news where assaults and verbal aggression by criminals can be seen. Public transportation units suffer from violence that authorities have not been able to reduce despite their efforts. This is why we have developed a fuzzy logic model that can adapt to almost any scenario thanks to the dynamism that we have implemented in each of its stages. We have obtained promising results that we believe will be of great help to the authorities for detecting the exact moment in which verbal aggression that is typical of a violent assault is happening in real time. This is a tool to help the authorities, not a substitution, we are simply making use of the latest technologies that are available to us. The goal of this paper is to provide a novel method for Mexican authorities in Mexico City in order to help the actual surveillance systems make faster decisions about whether violent assaults are happening or not.
Metadata-driven data migration from object-relational database to NoSQL document-oriented database
(Wydawnictwa AGH, 2022) Aggoune, Aicha; Namoune, Mohamed Sofiane
Object-relational databases (ORDB) are powerful tools for managing complex data, but they suffer from problems of scalability and managing large-scale data. Therefore, the importance of the migration of ORDB to NoSQL derives from the fact that the large volume of data can be handled in the best way with high scalability and availability. This paper reports a metadata-driven approach for the migration of ORDB to a document-oriented NoSQL database. Our data-migration approach involves three major stages: a pre-processing stage (to extract data and a schema’s components), a processing stage (to provide data transformation), and a post-processing stage (to store migrated data as BSON documents). This approach maintains the benefits of Oracle ORDB in NoSQL MongoDB by supporting integrity constraint checking. To validate our approach, we developed the OR2DOD (object relational to document-oriented database) system, and the experimental results confirm the effectiveness of our proposal.
Group membership management framework for decentralized collaborative systems
(Wydawnictwa AGH, 2022) Opioła, Łukasz; Jarosz, Kamil; Dutka, Łukasz; Słota, Renata; Kitowski, Jacek
Scientific and commercial endeavors could benefit from cross-organizational, decentralized collaboration, which becomes the key to innovation. This work addresses one of its challenges, namely efficient access control to assets for distributed data processing among autonomous data centers. We propose a group membership management framework dedicated for realizing access control in decentralized environments. Its novelty lies in a synergy of two concepts: a decentralized knowledge base and an incremental indexing scheme, both assuming a P2P architecture, where each peer retains autonomy and has full control over the choice of peers it cooperates with. The extent of exchanged information is reduced to the minimum required for user collaboration and assumes limited trust between peers. The indexing scheme is optimized for read-intensive scenarios by offering fast queries – look-ups in precomputed indices. The index precomputation increases the complexity of update operations, but their performance is arguably sufficient for large organizations, as shown by conducted tests. We believe that our framework is a major contribution towards decentralized, cross-organizational collaboration.
Modeling and analysis of probabilistic real-time systems through integrating event-b and probabilistic model checking
(Wydawnictwa AGH, 2022) Debbi, Hichem
Event-B is a formal method that is used in the development of safety-critical systems, however, these systems may introduce uncertainty and also need to meet real-time requirements, which make the modeling and analysis of such systems a challenging task. While some works exist that try to extend Event-B with probability and over time, they fail to address both in a single framework. Besides, these works mainly addressed extending the language itself, not integrating extended Event-B with verification. In this paper, we aim to represent both probability and time in the Event-B language, and we will show how such a representation can be automatically translated into the probabilistic timed automata (PTA) that are described in the language of the PRISM probabilistic model checker. This transformation approach would allow us to analyze the probabilistic and time-bounded probabilistic reachability properties of probabilistic real-time systems through probabilistic timed CTL (PTCTL) logic.