Journal of Information and Organizational Sciences

231-246

Authors: Karlo Babić; Francesco Guerra; Sanda Martinčić-Ipšić; Ana Meštrović

Measuring the semantic similarity of texts has a vital role in various tasks from the field of natural language processing. In this paper, we describe a set of experiments we carried out to evaluate and compare the performance of different approaches for measuring the semantic similarity of short texts. We perform a comparison of four models based on word embeddings: two variants of Word2Vec (one based on Word2Vec trained on a specific dataset and the second extending it with embeddings of word senses), FastText, and TF-IDF. Since these models provide word vectors, we experiment with various methods that calculate the semantic similarity of short texts based on word vectors. More precisely, for each of these models, we test five methods for aggregating word embeddings into text embedding. We introduced three methods by making variations of two commonly used similarity measures. One method is an extension of the cosine similarity based on centroids, and the other two methods are variations of the Okapi BM25 function. We evaluate all approaches on the two publicly available datasets: SICK and Lee in terms of the Pearson and Spearman correlation. The results indicate that extended methods perform better from the original in most of the cases.

257-273

Authors: Sofiane Boukelkoul; Ramdane Maamri

This paper presents a DSDEVS-based model “Dynamic Structure Discrete Event System specification” for modeling and simulating business processes with dynamic structure regarding to different contexts. Consequently, this model, formally, improves the reuse of configurable business processes. Thus, the proposed model allows the analysts to personalize their configurable business processes in a sound manner by verifying a set of structure properties, such as, the lack of synchronization and the deadlock by means of simulation. The implementation was done in DEVS-Suite simulator, which is based on DEVSJAVA models.

297-316

Authors: Michal Čerňanský; Ladislav Huraj; Marek Šimon

The paper focuses on design, background and experimental results of real environment of DDoS attacks. The experimental testbed is based on employment of a tool for IT automation to perform DDoS attacks under monitoring. DDoS attacks are still serious threat in both IPv4 and IPv6 networks and creation of simple tool to test the network for DDoS attack and to allow evaluation of vulnerabilities and DDoS countermeasures of the networks is necessary. In proposed testbed, Ansible orchestration tool is employed to perform and coordinate DDoS attacks. Ansible is a powerful tool and simplifies the implementation of the test environment. Moreover, no special hardware is required for the attacks execution, the testbed uses existing infrastructure in an organization. The case study of implementation of this environment shows straightforwardness to create a testbed comparable with a botnet with ten thousand bots. Furthermore, the experimental results demonstrate the potential of the proposed environment and present the impact of the attacks on particular target servers in IPv4 and IPv6 networks.

331-344

Authors: Paweł Kossecki

Common problem in valuation of telecommunication companies is finding comparable data and markets for valuation. The aim of this work was to identify comparable markets for the telecommunication market in Europe. A method for comparison of the markets based on the Multivariate Statistical Analysis was presented. The study covers twenty-two European countries. Using taxonomic measures, these countries were divided into five groups, taking into account the following variables: average monthly service cost of the fixed Internet, average cost of the mobile usage, and average cost of the fixed telephony usage. Within individual groups, the costs of telecommunications services are less diverse than in the entire population; their members can be considered comparable markets. The same method can be used for comparing markets in cases of enterprise valuations in the telecommunication sector, and also in analysis of their level of development.

365-382

Authors: Artur Soboń; Mirosław Kurkowski; Sylwia Stachowiak

Keeping the proper security level of ciphers used in communication networks is today a very important problem. Cryptanalysts ensure a constant need for improvement complexity and ciphers' security by trying to break them. Sometimes they do not instantly try to break the strongest version of the cipher, but they are looking for weaknesses by splitting it and independently checking all algorithm components. Often cryptanalysts also attempt to break cipher by using its weaker version or configuration. There are plenty of mechanisms and approaches to cryptanalysis to solve those challenges. One of them is SAT-based method, that uses logical encoding. In this article, we present our wide analysis and new experimental results of SAT-based, direct cryptanalysis of the RC5 cipher. To perform such actions on the given cipher, we initially create a propositional logical formula, that describes and represents the entire RC5 algorithm. The second step is to randomly generate key and plaintext. Then we determine the ciphertext. In the last step of our computations, we use SAT-solvers. They are particularly designed tools for checking the satisfiability of the Boolean formulas. In our research, we make cryptanalysis of RC5 cipher in the case with plaintext and ciphertext. To get the best result, we compared many SAT-solvers and choose several. Some of them were relatively old, but still very efficient and some were modern and popular.

33-50

Authors: Ivan Dunđer

Machine translation is increasingly becoming a hot research topic in information and communication sciences, computer science and computational linguistics, due to the fact that it enables communication and transferring of meaning across different languages. As the Croatian language can be considered low-resourced in terms of available services and technology, development of new domain-specific machine translation systems is important, especially due to raised interest and needs of industry, academia and everyday users. Machine translation is not perfect, but it is crucial to assure acceptable quality, which is purpose-dependent. In this research, different statistical machine translation systems were built – but one system utilized domain adaptation in particular, with the intention of boosting the output of machine translation. Afterwards, extensive evaluation has been performed – in form of applying several automatic quality metrics and human evaluation with focus on various aspects. Evaluation is done in order to assess the quality of specific machine-translated text.

83-112

Authors: Nur Zarifah Dhabitah Mahat, Mohd Hafiz Hanafiah

This paper aims to examine the impact of TripAdvisor reviews on behavioural intentions, basing on travellers' trust towards the e-WOM reviews. Four factors are proposed for building travellers’ trust and behavioural intentions: information quality, credibility, adoption and usefulness. Trust is expected to mediate the relationship between eWOM attributes and travellers’ behavioural intention. Data from 410 travellers were analysed using Partial Least Square-Structural Equation Modeling (PLS-SEM), and the findings show that TripAdvisor e-WOM attributes (information credibility, adoption and usefulness) significantly influence the traveller's trust. Besides, traveller behavioural intention was influenced considerably by TripAdvisor eWOM information credibility and usefulness. Lastly, trust in e-WOM significantly mediates travellers' behavioural intention. This paper confirms the importance of eWOM in the context of the tourism industry and travellers' trust and behaviour towards online review, which altered how consumers behave before deciding to travel.

141-156

Authors: Bambang Agus Pramuka, Margani Pinasti

Cloud technology is now becoming a valuable resource, as it provides cost-saving business technology. Businesses exist to earn a profit by keeping their capital and expenses low. In an attempt to address the issue, this study employs structural equation model to complement literature on users' technology acceptance behavior. The framework of the study was based on the technology acceptance model (TAM) to better understand the adoption of cloud computing by small businesses owners. This study looks at the perception and attitudes of small businesses (SMEs) towards cloud technology based accounting information systems, therefore, their intention to adopt the technology. Result support the view that perceived usefulness, ease of use and credibility positively influenced SMEs' attitudes towards cloud-based accounting information systems and therefore their intention to adopt the technology. The result enhances literature in the field of cloud-based accounting systems for small businesses.

171-184

Authors: Alexander Vanyushkin, Leonid Graschenko

The article discusses the evaluation of automatic keyword extraction algorithms (AKEA) and points out AKEA’s dependence on the properties of the test collection for effectiveness. As a result, it is difficult to compare different algorithms who’s tests were based on various test datasets. It is also difficult to predict the effectiveness of different systems for solving real-world problems of natural language processing (NLP). We take in to consideration a number of characteristics, such as the text length distribution in words and the method of keyword assignment. Our analysis of publicly available analytical exposition text which is typical for the keywords extraction domain revealed that their length distributions are very regular and described by the lognormal form. Moreover, most of the article lengths range between 400 and 2500 words. Additionally, the paper presents a brief review of eleven corpora that have been used to evaluate AKEA’s.

199-209

Authors: JIOS

The Journal of Information and Organizational Sciences (JIOS) upholds the highest standards of publication ethics and takes all possible measures against any publication malpractices.