Computer Science
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ISSN 1508-2806
e-ISSN: 2300-7036
Issue Date
2018
Volume
Vol. 19
Number
No. 1
Description
Reviewed by: Janusz Bobulski, Milan Rusko, Flavia Micota, Jaroslaw Rudy, Daniela Zaharie, Carlos Cotta, Jiuchuan Jiang, Michal Wrzeszcz, Bruno Veloso, Emir Huseyin Ozder, Javier Alonso, Vijai Kumar
Journal Volume
Computer Science
Vol. 19 (2018)
Projects
Pages
Articles
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.
New genetic algorithm based on dissimilarities and similarities
(Wydawnictwa AGH, 2018) Al-Jawadi, Radhwan; Studniarski, Marcin; Younus, Aisha
Optimization is essential for nding suitable answers to real life problems. In particular, genetic (or more generally, evolutionary) algorithms can provide satisfactory approximate solutions to many problems to which exact analytcal results are not accessible. In this paper we present both theoretical and experimental results on a new genetic algorithm called Dissimilarity and Simlarity of Chromosomes (DSC). This methodology constructs new chromosomes starting with the pairs of existing ones by exploring their dissimilarities and similarities. To demonstrate the performance of the algorithm, it is run on 17 two-dimensional, one four-dimensional and two ten-dimensional optimization problems described in the literature, and compared with the well-known GA, CMA-ES and DE algorithms. The results of tests show the superiority of our strategy in the majority of cases.
Audio-visual speech processing system for Polish applicable to human-computer interaction
(Wydawnictwa AGH, 2018) Jadczyk, Tomasz
This paper describes audio-visual speech recognition system for Polish language and a set of performance tests under various acoustic conditions. We first present the overall structure of AVASR systems with three main areas: audio features extraction, visual features extraction and subsequently, audiovisual speech integration. We present MFCC features for audio stream with standard HMM modeling technique, then we describe appearance and shape based visual features. Subsequently we present two feature integration techniques, feature concatenation and model fusion. We also discuss the results of a set of experiments conducted to select best system setup for Polish, under noisy audio conditions. Experiments are simulating human-computer interaction in computer control case with voice commands in difficult audio environments. With Active Appearance Model (AAM) and multistream Hidden Markov Model (HMM) we can improve system accuracy by reducing Word Error Rate for more than 30%, comparing to audio-only speech recognition, when Signal-to-Noise Ratio goes down to 0 dB.
Decision support system of discount pricing analysis using method of elimination et choix traduisant la realite (ELECTRE)
(Wydawnictwa AGH, 2018) Agustine, Victor Wiley; Lucas, Thomas
The development of e-commerce site operators in Indonesia is now faced with intense competition for defending the market segment, especially regarding how e-commerce sites are attracting consumers through specic marketing strategies. This study implements a decision support system approach to help marketers to determine price discount alternatives using the Elimination et Choix Traduisant la Realite (ELECTRE) method. The ELECTRE method is widely recognized for having good performance in analyzing customer behavior criteria, however, there is little information about discount analysis using the ELECTRE method. This study implements a method for consumer behavior simulation that can be aected by the criteria to make a purchase on a simulated e-commerce website. Our model estimates three parts of the matrices' analysis: (a) average value of discounted price (DP), (b) average value of pro- duct brand (PB), and (c) average value of purchase decision (PD). We used these as the main alternatives, e.g., price discounts as rst alternative (A1), brand discount as second alternative (A2), and purchase discount as third alternative (A3). Based on the results of the dominant aggregation matrix, the study found that the results are dominated by brand discount (A2). In other words, it is recommended for the decision maker to focus their discount on certain brands more precisely as a marketing strategy than price discount or purchase discount.
Emergence of population structure in socio-cognitively inspired ant colony optimization
(Wydawnictwa AGH, 2018) Byrski, Aleksander; Świderska, Ewelina; Łasisz, Jakub; Kisiel-Dorohinicki, Marek; Lenaerts, Tom; Samson, Dana; Indurkhya, Bipin
A metaheuristic proposed by us recently, Ant Colony Optimization (ACO) hybridized with socio-cognitive inspirations, turned out to generate interesting results compared to classic ACO. Even though it does not always find better solutions to the considered problems, it usually finds sub-optimal solutions usually. Moreover, instead of a trial-and-error approach to configure the parameters of the ant species in the population, in our approach, the actual structure of the population emerges from predefined species-to-species ant migration strategies. Experimental results of our approach are compared against classic ACO and selected socio-cognitive versions of this algorithm.