COMPUTER SCIENCE (CN-csci)

Permanent URI for this communityhttps://repo.agh.edu.pl/handle/AGH/102745

Adres wydawniczy: Kraków : Wydawnictwa AGH, 2004-
O czasopiśmie: http://csci.agh.edu.pl/
ISSN: 1508-2806 e-ISSN: 2300-7036
DOI: http://dx.doi.org/10.7494/csci

The main areas of interest of the journal are theoretical aspects of computer science, soft computing, HPC, cloud and distributed processing and simulation, multimedia systems and computer graphics, and natural language processing.

New! Aktualny numer: 2025 - Vol. 26 - No. 4

Roczniki i numery

Browse

Now showing 1 - 20 of 562

Access status: Open Access ,
A blackboard system for generating poetry
(Wydawnictwa AGH, 2016) Misztal-Radecka, Joanna; Indurkhya, Bipin
We present a system to generate poems based on the information extracted from input text such as blog posts. Our design uses the blackboard architecture, in which independent specialized modules cooperate during the generation process by sharing a common workspace known as the blackboard. Each module is responsible for a particular task while generating poetry. Our implementation incorporates modules that retrieve information from the input text, generate new ideas, or select the best partial solutions. These distinct modules (experts) are implemented as diverse computational units that make use of lexical resources, grammar models, sentiment-analyzing tools, and languageprocessing algorithms. A control module is responsible for scheduling actions on the blackboard. We argue that the blackboard architecture is a promising way of simulating creative processes because of its flexibility and compliance with the Global Workspace Theory of mind. The main contribution of this work is the design and prototype implementation of an extensible platform for a poetry-generating system that may be further extended by incorporating new experts as well as some existing poetrygenerating systems as parts of the blackboard architecture. We claim that this design provides a powerful tool for combining many of the existing efforts in the domain of automatic poetry generation.
Access status: Open Access ,
A cellular automata models of evolution of transportation networks
(Wydawnictwa AGH, 2002) Topa, Paweł; Paszkowski, Mariusz
We present a new approach to modelling of transportation networks. Supply of resources and their influence on the evolution of the consuming environment is a principal problem considered. We present two concepts, which are based on cellular automata paradigm. In the first model SCAMAN (Simple Cellular Automata Model of Anastomosing Network), the system is represented by a 2D mesh of elementary cells. The rules of interaction between them are introduced for modelling of the waterflow and other phenomena connected with anastomosing river. Due to limitations of SCAMAN model, we introduce a supplementary model. The MANGraCA (Model of Anastomosing Network with Graph of Cellular Automata) model beside the classical mesh of automata, introduces an additional structure: the graph of cellular automata, which represents the network pattern. Finally we discuss the prospective applications of the models. The concepts of future implementation are also presented.
Access status: Open Access ,
A client-based encryption model for secure data storing in publicly available storage systems
(Wydawnictwa AGH, 2019) Retinger, Marek
This document presents a conceptual model of a system for protecting thedata stored in publicly available data storage systems. The main idea was toapply encryption on both the client and server sides that would consequentlyhave a significant impact on data security. The compatibility with existingsystems allows us to deploy the solution fast and at a low cost. The testsconducted on a simplified implementation have confirmed the solution’s validity,and they have shown some possible performance issues as compared to theclassical system (which can be easily bypassed).
Access status: Open Access ,
A compile-time deadlock detection pattern
(2007) Korzycki, Michał
The paper presents the application of the trait technique in generic programming for compiletime deadlock detection and prevention in multihreaded applications.
Access status: Open Access ,
A crisis management approach to mission survivability in computational multi-agent systems
(Wydawnictwa AGH, 2010) Byrski, Aleksander; Kisiel-Dorohinicki, Marek; Carvalho, Marco
In this paper we present a biologically-inspired approach for mission survivability (considered as the capability of fulfilling a task such as computation) that allows the system to be aware of the possible threats or crises that may arise. This approach uses the notion of resources used by living organisms to control their populations. We present the concept of energetic selection in agent-based evolutionary systems as well as the means to manipulate the configuration of the computation according to the crises or user's specific demands.
Access status: Open Access ,
A density-based method for the identification of disjoint and non-disjoint clusters with arbitrary and non-spherical shapes
(Wydawnictwa AGH, 2021) Ben Ncir, Chiheb-Eddine
The ability of clustering methods to build both disjoint and non-disjoint partitionings of data has become an important issue in unsupervised learning. Although this problem has been studied during the last decades resulting in several proposed overlapping clustering methods in the literature, most of existing methods fail to look for clusters having arbitrary and non-spherical shapes. In addition, most of these existing methods require to pre-configure the number of clusters in prior, which is not a trivial task in real life application of clustering. To solve all these issues, we propose in this work a new density based overlapping clustering method, referred to as OC-DD, which is able to detect both disjoint and non-disjoint partitioning even when boundaries between clusters have complex separations with arbitrary forms and shapes. The proposed method is based on density and distances to detect highly dense regions and connected groups in data without the necessity to pre-configure the number of clusters. Experiments performed on artificial and real multi-labeled datasets have shown the effectiveness of the proposed method compared to the existing ones.
Access status: Open Access ,
A DHCR_SmartNet: a smart Devanagari handwritten character recognition using level-wised CNN architecture
(Wydawnictwa AGH, 2022) Deore, Shalaka Prasad
Handwritten script recognition is a vital application of the machine-learning domain. Applications like automatic license plate detection, pin-code detection, and historical document management increases attention toward handwritten script recognition. English is the most widely spoken language in India, hence, there has been a lot of research into identifying a script using a machine. Devanagari is a popular script that is used by a large number of people on the Indian subcontinent. In this paper, a level-wised efficient transfer-learning approach is presented on the VGG16 model of a convolutional neural network (CNN) for identifying isolated Devanagari handwritten characters. In this work, a new dataset of Devanagari characters is presented and made accessible to the public. This newly created dataset is comprised of 5800 samples for 12 vowels, 36 consonants, and 10 digits. Initially, a simple CNN is implemented and trained on this new small dataset. During the next stage, a transfer-learning approach is implemented on the VGG16 model, and during the last stage, the efficient fine-tuned VGG16 model is implemented. The obtained accuracy of the fine-tuned model’s training and testing came to 98.16% and 96.47%, respectively.
Access status: Open Access ,
A nature-inspired hybrid partitional clustering method based on grey wolf optimization and JAYA algorithm
(Wydawnictwa AGH, 2023) Shial, Gyanaranjan; Saho, Sabita; Panigrahi, Sibarama
This paper presents a hybrid meta-heuristic algorithm that uses the grey wolf optimization (GWO) and the JAYA algorithm for data clustering. The idea is to use the explorative capability of the JAYA algorithm in the exploitative phase of GWO to form compact clusters. Here, instead of using only one best and one worst solution for generating offspring, the three best wolves (alpha, beta and delta) and three worst wolves of the population are used. So, the best and worst wolves assist in moving towards the most feasible solutions and simultaneously it helps to avoid from worst solutions, this enhances the chances of trapping at local optimal solutions. The superiority of the proposed algorithm is compared with five promising algorithms, namely, the sine-cosine (SCA),GWO, JAYA, particle swarm optimization (PSO), and k-means algorithms.The performance of the proposed algorithm is evaluated for 23 benchmark mathematical problems using the Friedman and Nemenyi hypothesis tests. Additionally, the superiority and robustness of our proposed algorithm is tested for 15 data clustering problems by using both Duncan's multiple range test and the Nemenyi hypothesis test.
Access status: Open Access ,
A new approach to storing dynamic data in relational databases using JSON
(Wydawnictwa AGH, 2018) Piech, Mateusz; Marcjan, Robert
JavaScript Object Notation was originally designed to transfer data. However, it soon found another use as a way to persist data in NoSQL databases. Recently, the most popular relational databases introduced JSON as native column type, which makes it easier to store and query dynamic database schema. In this paper, we review the currently popular techniques of storing data with a dynamic model with a large number of relationships between entities in relational databases. We focus on creating a simple dynamic schema with JSON in the most popular relational databases and we compare it with well-known EAV/CR data model and the document database. The results of precisely selected tests in the field of Criminal Data suggest that the use of JSON in dynamic database schema greatly simplifies queries and reduces their execution time compared to widely used approaches.
Access status: Open Access ,
A new approach to the rule-based systems design and implementation process
(2004) Nalepa, Grzegorz J.
The paper discusses selected problems encountered in practical rule-based systems (RBS) design and implementation. To solve them XTT, a new visual knowledge representation is introduced. Then a complete, integrated RBS design, implementation and analysis methodology is presented. This methodology is supported by a visual CASE tool called Mirella.The main goal is to move the design procedure to a more abstract, logical level, where knowledge specification is based on use of abstract rule representation. The design specification is automatically translated into Prolog code, so the designer can focus on logical specification of safety and reliability. On the other hand, system formal aspects are automatically verified on-line during the design, so that its verifiable characteristics are preserved.
Access status: Open Access ,
A note on hardness of multiprocessor scheduling with scheduling solution space tree
(Wydawnictwa AGH, 2023) Dwibedy, Debasis; Mohanty, Rakesh
We study the hardness of the non-preemptive scheduling problem of a list of independent jobs on a set of identical parallel processors with a makespan minimization objective. We make a maiden attempt to explore the combinatorial structure of the problem by introducing a scheduling solution space tree (SSST) as a novel data structure. We formally define and characterize the properties of SSST through our analytical results. We show that the multiprocessor scheduling problem is $\cal {NP}$-complete with an alternative technique using SSST and weighted scheduling solution space tree (WSSST) data structures. We propose a non-deterministic polynomial-time algorithm called magic scheduling (MS) based on the reduction framework. We also define a new variant of multiprocessor scheduling by including the user as an additional input parameter, which we called the multiuser multiprocessor scheduling problem (MUMPSP). We also show that MUMPSP is $\cal {NP}$-complete. We conclude the article by exploring several non-trivial research challenges for future research investigations.
Access status: Open Access ,
A novel adaptive checkpointing method based on information obtained from workflow structure
(Wydawnictwa AGH, 2016) Kail, Eszter; Kacsuk, Péter; Kozlovszky, Miklós
Scientific workflows are data- and compute-intensive, thus, they may run for days or even weeks on parallel and distributed infrastructures such as grids, supercomputers, and clouds. In these high-performance computing infrastructures, the number of failures that can arise during scientific-workflow enact- ment can be high, so the use of fault-tolerance techniques is unavoidable. The most-frequently used fault-tolerance technique is taking checkpoints from time to time, when failure is detected, the last consistent state is restored. One of the most-critical factors that has great impact on the effectiveness of the checkpointing method is the checkpointing interval. In this work, we propose a Static (Wsb) and an Adaptive (AWsb) Workflow Structure Based checkpointing algorithm. Our results showed that, compared to the optimal checkpointing strategy, the static algorithm may decrease the checkpointing overhead by as much as 33% without affecting the total processing time of workflow execution. The adaptive algorithm may further decrease this overhead while keeping the overall processing time at its necessary minimum.
Access status: Open Access ,
A novel approach to automated behavioral diagram assessment using label similarity and subgraph edit distance
(Wydawnictwa AGH, 2021) Fauzan, Reza; Siahaan, Daniel Oranova; Rochimah, Siti; Triandini, Evi
The Unified Modeling Language (UML) is one of the standard languages that are used in modeling software, therefore, UML is widely taught in many universities. Generally, teachers assign students to build UML diagram designs based on a predetermined project, however, the assessment of such assignments can be challenging, and teachers may be inconsistent in assessing their students’ answers. Thus, automated UML diagram assessment becomes essential to maintaining assessment consistency. This study uses a behavioral diagram as the object of research, since it is a commonly taught UML diagram. The behavioral diagram can show a dynamic view of the software. This study proposes a new approach to automatically assessing the similarity of behavior diagrams as reliably as experts do. We divide the assessment into two portions: semantic assessment, and structural assessment. Label similarity is used to calculate semantic assessment, while subgraph edit distance is used to calculate structural assessment. The results suggest that the proposed approach is as reliable as an expert in assessing the similarity between two behavior diagrams. The observed agreement value suggests a strong agreement between the use of experts and the proposed approach.
Access status: Open Access ,
A novel hybrid deep learning approach for 3D object detection and tracking in autonomous driving
(Wydawnictwa AGH, 2024) Dheepika, PS; Umadevi, V
Recently Object detection and tracking using fusion of LiDAR and RGB camera for the autonomous vehicle environment is a challenging task. The existing works initiates several object detection and tracking frameworks using Artificial Intelligence (AI) algorithms. However, they were limited with high false positives and computation time issues thus lacking the performance of autonomous driving environment. The existing issues are resolved by proposing Hybrid Deep Learning based Multi Object Detection and Tracking (HDL-MODT) using sensor fusion methods. The proposed work performs fusion of solid state LiDAR, Pseudo LiDAR, and RGB camera for improving detection and tracking quality. At first, the multi-stage preprocessing is done in which noise removal is performed using Adaptive Fuzzy Filter (A-Fuzzy). The pre-processed fused image is then provided for instance segmentation to reduce the classification and tracking complexity. For that, the proposed work adopts Lightweight General Adversarial Networks (LGAN). The segmented image is provided for object detection and tracking using HDL. For reducing the complexity, the proposed work utilized VGG-16 for feature extraction which forms the feature vectors. The features vectors are then provided for object detection using YOLOv4. Finally, the detected objects were tracked using Improved Unscented Kalman Filter (IUKF) and mapping the vehicles using time based mapping by considering their RFID, velocity, location, dimension and unique ID. The simulation of the proposed work is carried out using MATLAB R2020a simulation tool and performance of the proposed work is compared with several metrics that show that the proposed work outperforms than the existing works.
Access status: Open Access ,
A parallel algorithm of icsym forcomplexsymmetric linear systems in quantum chemistry
(Wydawnictwa AGH, 2018) Zhang, Yingchun; Lv, Quanyi; Xiao, Manyu; Xie, Gongnan; Breitkopf, Piotr
Computational effort is a common issue for solving large-scale complex symmetric linear systems, particularly in quantum chemistry applications. In order to alleviate this problem, we propose a parallel algorithm of improved conjugate gradient-type iterative (ICSYM). Using three-term recurrence relation and or- thogonal properties of residual vectors to replace the tridiagonalization process of classical CSYM, which allows to decrease the degree of the reduce-operator from two to one communication at each iteration and to reduce the amount of vector updates and vector multiplications. Several numerical examples are implemented to show that high performance of proposed improved version is obtained both in convergent rate and in parallel efficiency.
Access status: Open Access ,
A parallel approach for metaheuristics solving the labs problem using CPU and GPU
(Wydawnictwa AGH, 2025) Żurek, Dominik; Piętak, Kamil; Pietroń, Marcin; Kisiel-Dorohinicki, Marek
This paper contributes to solving the low autocorrelation binary sequence (LABS) problem that remains an open hard-optimization problem with many applications. The current direction of research is focused on developing algorithms dedicated to parallel architectures such as GPGPU or multi-core CPUs. The paper follows this direction and proposes new heuristics developed from the steepest-descent local search algorithm that extends the notion of a neighborhood of a given sequence. The introduced algorithms utilize the parallel nature of multicore CPUs and provide an effective method for solving the LABS problem. The efficiency levels of SDSL and the new algorithm are presented; to ensure an effective comparison, they were both implemented in the same manner. The comparison shows that exploring the larger neighborhood improves the efficiency of the search method.
Access status: Open Access ,
A physical model of quantum bit behavior based on a programmable FPGA integrated circuit
(Wydawnictwa AGH, 2024) Długopolski, Jacek; Sadowski, Marcin; Suleja, Wawrzyniec
The rapidly developing field of quantum computing and the ongoing lack of widely available quantum computers create the need for scientists to build their simulators. However, mathematical simulation of such circuits usually ignores many aspects and problems found in real quantum systems. In this article, the authors describe a quantum bit emulator based on FPGA integrated circuits. In this case, FPGA technology provides real-time massive parallelism of the modeled physical phenomena. The modeled QUBIT is represented using a Bloch sphere. Its quantum state is set and modified only by precise pulses of an electrical signal, and with the help of similar pulses, it manifests its current state in real time. The constructed QUBIT was additionally equipped with decoherence mechanisms and with circuits that intentionally respond to internal and external noises that distort its current quantum state. This article presents and discusses how such a physically built emulator works.
Access status: Open Access ,
A proposal of digital contents copyright protection by using blockmarking technique
(Wydawnictwa AGH, 2024) Lê, Danh Tai; Tạ, Minh Thanh
Recently, blockmarking technique \cite{blockmarking} is proposed for a new hybrid model based on the combination of blockchain and watermarking method. In this model, it not only achieves the goal of image copyright protection but also stores the image into the blockchain network such as IPFS system. In this paper, we propose a new DRM system by inheriting the idea of blockmarking. The copyright contents can be distributed via IPFS blockchain, then be restored by using the reconstruction license for each legal user. Also, in our method, based on the reconstruction licenses, the distributed contents can be reconstructed from IPFS with various watermarking patterns. It helps us can manage the legal users and trace the traitor if a dispute occurs. The experimental results show that our method successfully achieved the purpose of digital copyright protection.
Access status: Open Access ,
A proposition of knowledge management methodology for the purpose of reasoning with the use of an upper-ontology
(2007) Szymański, Kamil; Dobrowolski, Grzegorz; Koźlak, Jarosław; Zygmunt, Anna
This article describes a proposition of knowledge organization for the purpose of reasoning using an upper-ontology. It presents a model of integrated ontologies architecture which consists of a domain ontologies layer with instances, a shared upper-ontology layer with additional rules and a layer of ontologies mapping concrete domain ontologies with the upper-ontology. Thanks to the upper-ontology, new facts were concluded from domain ontologies during the reasoning process. A practical realization proposition is given as well. It is based on some popular Semantic Web technologies and tools, such as OWL, SWRL, nRQL, Protege and Racer.
Access status: Open Access ,
A routing algorithm and a router architecture for 3D NoC
(Wydawnictwa AGH, 2019) Kanagasabapathi, Somasundaram; Calicut, Chythanya
In recent years, the enhancement of microchip technologies has enabled large scale Systems-on-Chip (SoC). Due to sharp increase in number of processing elements, SoC faces various challenges in design and testing. Network on Chip (NoC) is an alternative technology to overcome the challenges in SoC design and testing. NoC emerged as a key architecture that allows one to optimize the parameters like power and area. In spite of its applications, NoC faces some real time challenges like designing an optimum topology, routing scheme and application mappings. In this paper, we address the main three issues on NoC, namely, designing of an optimal topology, routing algorithm and a router design for the topology. First, we propose a topology and a routing algorithm. We prove that our recursive network topology is Hamiltonian connected and we propose an algorithm for data packet transmissions, which is free from cyclic deadlocks and the algorithm maximizes the congestion factor. Our experimental results show that the proposed topology gives better performance in terms of average latency and power than the other topologies. Finally, we propose a router architecture for our 3D-NoC. The router architecture is based on shared buffers. Also, our experimental results indicate that the proposed router architecture consumes less area and power than the Virtual Channel architecture.