VoIP Security

Internetová telefonie se dnes stává stále oblíbenější alternativou klasické telefonní služby. Důvodem může být její cena a také dostupnost. S oblíbeností rostou ale také rizika případného zneužití přenášených informací. Způsobů, jak zabezpečit VoIP komunikaci, se nabízí několik. Tato práce je věnována především jednomu, kterým je využití Secure RTP. Bude provedena jeho implementace do softwarové telefonní ústředny Asterisk a ověřena funkčnost zkušebními hovory i analýzou siťového provozu.Internet telephony becomes still more popular option to common telephone service. Reason may be it's price as well as availability. With growing popularity grows the risk of unauthorized use of transferred data too. There are several ways to secure VoIP communication. This bachelor's thesis talk about one of many, which is use of Secure RTP. There will be made it's implementation in the software telephone exchange Asterisk and tested functionality by trial talks and analysis of network traffic as well.

New approach to evaluate the TOWS matrix and its application in a mining company

SWOT analyses and the closely related TOWS matrix are frequent starting points for an organization to develop its strategy. The paper deals with the evaluation of the TOWS matrix and presents three novel approaches to evaluate the different factors of the TOWS matrix, namely (1) approach to evaluate the factors with identical weights; (2) approach to evaluate factors with their weights determined within the different quadrants of the TOWS matrix; and (3) approach to evaluate factors with weights determined within the whole TOWS matrix. The third approach has two variants. The proposed approaches to evaluate the TOWS matrix were tested on a SWOT analysis of a significant mining company in the Czech Republic. The results imply that the strategy W-T (weaknesses-threats) is recommended in three cases, while the strategy S-T (strengths-threats) is recommended once. The paper may be valuable for managers responsible for strategic planning.Web of Science118121303129

The algorithm by Ferson et al. is surprisingly fast: An NP-hard optimization problem solvable in almost linear time with high probability

We start with the algorithm of Ferson et al. (\emph{Reliable computing} {\bf 11}(3), p.~207--233, 2005), designed for solving a certain NP-hard problem motivated by robust statistics. First, we propose an efficient implementation of the algorithm and improve its complexity bound to $O(n \log n+n\cdot 2^\omega)$, where $\omega$ is the clique number in a certain intersection graph. Then we treat input data as random variables (as it is usual in statistics) and introduce a natural probabilistic data generating model. On average, we get $2^\omega = O(n^{1/\log\log n})$ and $\omega = O(\log n / \log\log n)$. This results in average computing time $O(n^{1+\epsilon})$ for $\epsilon > 0$ arbitrarily small, which may be considered as ``surprisingly good'' average time complexity for solving an NP-hard problem. Moreover, we prove the following tail bound on the distribution of computation time: ``hard'' instances, forcing the algorithm to compute in time $2^{\Omega(n)}$, occur rarely, with probability tending to zero faster than exponentially with $n \rightarrow \infty$

Artificial intelligence, creativity and education: finding a new perspective

This review study aims to clarify the relationship between creativity development and artificial intelligence in education. Although this is a media-emphasised topic and individual technology projects (ChatGPT, Dalee-2, Midjourney) are part of educational activities, a more comprehensive analysis of the specific emphasis on creativity still needs to be provided. The study's novelty lies in synthesising current knowledge and forming recommendations about the relationship between creativity and AI in education. The study analyses 16 documents from the Web of Science database and, based on these, identifies six broad categories for critical reflection on the phenomenon of educational practice: the need to rethink the educational environment, goals and objectives, the emphasis on AI literacy, the focus on topics related to the future and its problems, the importance of developing theoretical conceptualisation of problems and abstract models in the curriculum, the connection with computational thinking, and the integration into the whole curriculum instead of isolated courses

The history of chatbots: the journey from psychological experiment to educational object

Chatbots represent a strong and distinctive theme in the current literature on technology in education. What is lacking, however, is an analysis of them in terms of historical development or deeper historical-discursive classification. This paper focuses on the history of chatbots and places it in the context of a critical reflection on studies focusing on chatbots as educational objects between 2006-2021. It offers an analysis of each study and places them in the context of the development of the field as a whole. The study identifies three vital discourses that can be identified in the development of chatbots from a historical perspective - Turing-oriented, Searle-oriented and educational interaction-oriented

MOOCs as part of the university curriculum: A case study

Massive Open Online Courses (MOOCs) sind seit 2012 ein fester Bestandteil der Bildungslandschaft. In den letzten zehn Jahren haben sie einerseits eine massive Entwicklung erfahren, die mit dem Aufkommen von Plattformen wie Coursera, edX, Udemy oder FutureLearn verbunden ist. Gleichzeitig ist jedoch klar geworden, dass sie nicht als Ersatz für die traditionelle formale Universitätsausbildung angesehen werden können. Am Fachbereich für Informationsstudien und Bibliothekswesen der Masaryk-Universität werden MOOCs den Studierenden als Teil eines bestimmten Kurses angeboten, in dem sie Unterstützung und Feedback erhalten. Das Lernen ist auch mit Credits verbunden, was die Motivation der Studierenden, den Kurs zu absolvieren, erhöht. Die Forschung wird mit Daten aus Fragebögen in der ersten Woche und am Ende des Kurses arbeiten (n=18). Auf der Grundlage der Daten werden wir Erkenntnisse für die Durchführung anderer ähnlicher Kurse anbieten. Die Unterstützung durch die Universität in Form von Motivation und einem Gefühl der Sicherheit ist entscheidend. Die Studierenden weisen hohe Abschlussquoten auf, wenn sie den Kurs als Teil ihres Lehrplans belegen. Andererseits nennen sie ihre Unfähigkeit, gut mit der Zeit umzugehen und ihre Aufgaben zu organisieren, als ein wesentliches Hindernis.Massive Open Online Courses (MOOCs) have been widely part of the educational landscape since 2012. Over the last decade, they have seen, on the one hand, a massive development associated with the emergence of platforms such as Coursera, edX, Udemy or FutureLearn. Still, at the same time, it has become clear that they cannot be considered as a substitute for traditional formal university education. At the Department of Information Studies and Library Science at Masaryk University, MOOCs are offered to students as part of a particular course in which they receive support and feedback. The learning is also linked to credits, which increases students' motivation to complete the course. The research will work with data from questionnaires in the first week and at the end of the course (n=18). The research will offer insights for running other similar courses based on the data. University support in terms of motivation and a sense of security is crucial. Students show high completion rates if they study the course as part of their curriculum. On the other hand, they name their inability to work well with time and organise their tasks as a significant barrier

Cyberspace as a Metaphor of Being Online or a Particular form of Space Organization?

Cyberspace gradually becomes a place (state, space) in which more and more interactions between users take place. The boundaries between online and offline are progressively being washed away, and it will be increasingly important to be able to work with it adequately for research in pedagogy and historiography. I aimed to create an empirical probe into how the term “cyberspace” works by students of the Faculty of Arts of Masaryk University in Brno, or how they perceive it. For the research, I used the study of metaphors

Creation of a 13-Item Bedside Dysphagia Screening Test

Dysphagia is a common problem that affects people with many health conditions and that can have serious complications. Various dysphagia screening tests exist; however, their creation was associated with certain weaknesses, e.g. none of them used “objective” instrumental tests (e.g., videofluoroscopy or flexible endoscopic examination of swallowing, FEES) in all patients to verify the results. In addition, most dysphagia screening tests were developed for stroke patients. The purpose of this study was to fill this gap. Our research included not only patients with stroke but also patients with other neurological and otorhinolaryngologic conditions. We tested 33 physical examination items in 44 patients and analyzed the results by comparing them to FEES results. Our study is the first one that performed this kind of comparison in all the patients enrolled in the study. Data mining was used to create a 13-item dysphagia screening test that has 88.2% sensitivity

Proctoring as a journey to quality education? A critical review of the literature

The paper aims to analyse the current professional discourse and to map the current views and attitudes of proctoring online exam formats across the globe. The entire theoretical delineation focuses mainly on college or university formats. We introduce the international context in the first part and then discuss the analysis of the texts found in the review study at Scopus and Web of Science databases. The study results in a comprehensive summary of the positive and negative implementation aspects of proctoring. We also reach a new categorisation of the different methods used to control proctoring online exams. The study should provide synthesising findings with easy applicability. Our results may be valuable for educational institutions or others interested in online learning and online proctoring processes, not only when considering implementation