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IMS security solutions
Porubský, Tomáš ; Rášo, Ondřej (referee) ; Mácha, Tomáš (advisor)
In the first part of my master's thesis the network architecture of IMS (IP Multimedia Subsystem) is presented. The database of subscribers HSS (Home Subscriber Server) and SLF (Subscription Locator Function), as well as a SIP CSCF servers (Call Session Control Functions) process a SIP signalization and an AS application server performing services, etc. I focus on the registration of subscribers in the IMS network with a list of transmitted messages and description of each interface that is used in this network. The most important interfaces, which I described here, are Gm, Mw, Cx, Dx and Sh. Then I focused on security in IMS problems, which are divided into categories of access security and network security. After that is the implementation of IMS network in an open source Open IMS Core System considered under the Linux operating system. Here is the problem description from the actual system installation, through the configuration of all necessary elements of the network to the communication party itself. The communication analysis in the initial registration process and in subsequent communications is described. Finally I created laboratory exercises with a focus on the Open IMS Core System, where students learn about architecture and principle of networks based on IMS technology operation, with individual elements necessary for the operation of the network and their configuration. Students also test simple captured traffic analysis.
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SDL model for Source Specific Multicast
Záň, Stanislav ; Skořepa, Michal (referee) ; Šimek, Milan (advisor)
This work deals with questions of IP net communication, with using metod Source-Specific Multicast. It focused on questions of registration, unregistration and administration of clients in multicast group and IGMP protocol, which is made for this communication. Work deals also about problems of signalization between source of data and clients of multicast group.In the introduction of this work questions of communications in multicast are analyse. I tis followed by the chapter focused on the specific metod of multicast – Source Specific Multicast (SSM). Next chapter is based on the protocols in SSM, which are used for distribution of data stream in source to clients direction and also in the reverse direction. The net chapter deals with signalization of communication in SSM. It specializes for reflection and summarization metods, which are used here. This chapter also shows basic matematics formules for sending signalization packets and proposes other solutions and ways for simplify communication and minimalize delay, which is for signallization very important. After that, the work deals with differences between these two metods of signalization. The aplicationis builded in practical part of work from the knowlidge of theory from previous chapters and it simulates the real communication between data source and clients situated to multicast group. This communication is explained in MSC diagrams. The aplication also simulates both used metods of signalization and real count of cients in multicast group. The results of simulation are interpreted in the last part of work.
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Possibilities of connecting the Asterisk softswitch to the 4th generation PBX
Halamík, Zdeněk ; Krajsa, Ondřej (referee) ; Šilhavý, Pavel (advisor)
This master’s thesis dissertate the possibilities of the linkage between Asterisk softswitch and the 4th generation private branch exchange. This should create a new generation’s network, so-called NGN, by the convergence of existing telecommunication networks with an IP computer network. This master’s thesis is divided into several chapters. In introduction is described the evolution of the private branch exchanges as well as the principles of the voice digitizing, codecs and signaling commonly used in both TDM and VoIP networks. The main aim of this project is the configuration of Asterisk software exchange for connection with PBX Alcatel 4400 as well as public phone network PSTN. Another goal of this master’s thesis was the configuration of Alcatel PBX and diagnostics of CCS and CAS signaling on E1 interface. In conclusion there are summarized advantages of NGN networks and their utilization in the future.
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Converged solution of speech services
Mácha, Tomáš ; Kovář, Petr (referee) ; Novotný, Vít (advisor)
Development in VoIP technology is connected with the rapid growth of quality and data rate of the Internet connection. The application of the VoIP technology has become one of the key areas in telecommunication and networking. The main task of this thesis was to explore the questions of IP telephony and voice transmission over data networks according to H.323, SIP and Cisco architectures. Next focus was on designing and implementing experimental workplaces of mentioned architectures and their converged solutions. The purpose of the first chapter is to introduce the theory background of architectures required for implementation of real-time services in data networks and their comparison. The key objectives of the second and third part are to design and implement experimental workplaces containing signaling and proxy servers and hardware or software IP phones of several architectures. Illustration examples of different network topologies are included to demonstrate designed and realized VoIP solutions. Several tests of established communication are done using a packet analyzer. These tests examine duplex data transmission over IP. This article also contains two laboratory exercises designed according to gained practical experiences. The laboratory exercises provide an overview of theory and clearly indicate the possibilities of IP telephony.
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Is Leonardo DiCaprio good investment?
Kopecký, Daniel ; Melzochová, Jitka (advisor) ; Čermáková, Klára (referee)
This thesis researches whether there is an effect of casting Leonardo DiCaprio or other star actors in a film on the revenue of the given film and what the effect is, respectively. The data consists of a sample of 905 films screened between 2005-2015 in the United States of America and Canada. The results estimated by the method of least squares indicate that star actors have a positive influence on revenue. The presence of a financialy successful actor means 12% increase in revenue. On the other hand, Oscar-awarded actors influence revenue to a lesser degree. The hypothesis about Leonardo DiCaprios influence could not be either confirmed or denied. Other factors researched were e.g. budget, ratings, whether there is a sequel or director, among others. The variable with the most positive influence is budget; the existence of a sequel is the second most decisive factor.
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Are we watching good movies? The impact of audience rating on attendance and revenues of Czech movies
Žofčák, Jakub ; Stroukal, Dominik (advisor) ; Babin, Jan (referee)
Based on regression analysis and data set of 314 Czech movies from period 2003--2013, this thesis examines the hypothesis, that there is positive relationship between success of those movies (measured by attendance and revenues) and users rating in Česko-Slovenská filmová databáze. This hypothesis was confirmed by model presented in this thesis -- one percent increase in users rating is in relationship with increased attendance by 1,45% and revenues by 1,39%. Similar links between explained variables and other factors are also proved. As significant factor are proved favorite actress (but not favorite actors), favorite directors, Český lev awards and specific movie genre (action movies, fairy-tales and comedy). This thesis' contribution consists not only in application of chosen method on Czech environment, but also in economic explanation of positive relationship of certain specific variables in context of Czech movie industry. Among those specific variables associated with attendance and revenues is production of director Zdeněk Troška.
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Tick sialostatins L and L2 differentially influence dendritic cell responses to Borrelia spirochetes
PÁLENÍKOVÁ, Jana
Transmission of pathogens by ticks is greatly supported by tick saliva released during feeding. Dendritic cells (DC) act as immunological sentinels and interconnect the innate and adaptive immune system. They control polarization of the immune response towards Th1 or Th2 phenotype. We investigated whether salivary cystatins from the hard tick Ixodes scapularis, sialostatin L (Sialo L) and sialostatin L2 (Sialo L2), influence mouse dendritic cells exposed to Borrelia burgdorferi and relevant Toll-like receptor ligands.
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Adverse Effects of Monetary Policy Signalling
Matějů, Jakub ; Filáček, Jan
Assuming information asymmetry between private agents and the central bank about the state of the economy, an unexpected change in interest rates signals the central bank’s perceived state of the economy and facilitates an update of private expectations in an adverse, perhaps unintended way. This “updating channel” might counteract the standard transmission from interest rates to inflation and output. We develop a simple model laying down a theoretical basis for the adverse effects of monetary policy signalling. We also detect the presence of the updating channel in private forecasts of inflation in a cross-country sample of selected OECD countries.
Fulltext:  PDF
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Strategies in pay-per-bid auctions
Podešva, Jiří ; Svoboda, Miroslav (advisor) ; Dudáková, Tereza (referee)
In this paper I analyze pay-per-bid auctions. On the bids made in auctions I research strategies of players. I confirmed the hypothesis that players timed signal bids. I have demonstrated that shortening the interval extension auction decreases signaling in the auctions. Then I haven't demonstrated reduction signaling in beginner auctions. I also concluded, that the benefits in form of restoration of half used coupons for the player who was at the second place, doesn't increase the average number of bids made in auctions. My final conclusion is that the auctions with cheaper goods introduce on average higher returns for auctioneer than the auctions with more expensive goods.
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