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Security of wireless computer networks
Jelínek, Martin ; Pelka, Tomáš (referee) ; Doležel, Radek (advisor)
The master's thesis deals with the issue of Wireless Local Area Network (WLAN) from the viewpoint of the security and functional principle of security mechanisms. The transition to the issue concerning the security is accompanied by the methods of wireless data transmission operating on the level of physical layer (FHSS, DSSS, OFDM, MIMO), which is followed by the summary of individual 802.11 standards. The next part deals with the issue of shared transmission medium (CSMA/CA), influence of interference and correcting mechanisms (RTS/CTS). Within the security, the principles of the authentication along with the commonly used methods of security (WEP, WPA, WPA2) are described in detail. The first part concerning security deals with the security in the form of the WEP protocol, which is considered insufficient nowadays and points out the imperfect implementation and the consequent risks. The following part describes the security in the form of WPA which eliminates the implementation weaknesses of the previous WEP security protocol. The description of commonly used mechanisms of authentication (PSK, 802.1x), required temporary key management (PTK, GTK), data integrity (MIC) and encryption which uses TKIP protocol are also included. The last part, possible WLAN security, is aimed at the full support of 802.11i standard, which is called WPA2 (sometimes RSN). That part describes the basic encryption security element CCMP, which is based on the AES block cipher modes. The practical part of the thesis deals with the security verification of current wireless networks. In the process of verification the accessible HW means and programming tools of Open Source Software (OSS) are used. By means of verification it has been pointed out that there are possible security risks resulting from the security method which has been used. Also several recommendations how to reduce the security risks of the used method to minimum are mentioned.
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Analyze of Open Source solutions for a small and middle size companies
Veselý, Jakub ; Veselý, Petr (referee) ; Dydowicz, Petr (advisor)
The object of this Bachelor‘s thesis is to describe the current software situation among small and medium companies and to demonstrate the possibilities of Open Source applications compared to closed source software. The possibilities of Open Software are clarified in terms of testing and studies. Case tudies show the potential of OSS/FS implementation in real environment. This work discovers the main benefits and disadvantages of Open Software and the reasons for their hitherto small usage.
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Network server performance when communicating with a great number of clients
Mašín, Jan ; Pelka, Tomáš (referee) ; Komosný, Dan (advisor)
The aim is to create a simulation system between two computers of the server-client type to generace the process to server while usany UDP protocol: to set different parameters of the generated process (size of paquet, interval of sending) and evaluace the server-sources consumption (memory), to work out the outcomes in a well-organized manner. There have been tested two servers (each of different output) and operational systéme Windows XP, Windows Server 2003, Linux Mandriva 8.0 and Linux Fedora 7, each of these had been installed on the servers with different outputs. The generated process is carried out with usaje of the paquet generator made in the programming language C++.Two different programmes needed have been created, one of them for klient(paquet generation in OS Windows), its aim is to generate the paquets, the sekond on efor server (functional version working in OS Linux had had to be made) receiving the generated paquets. Evaulation of the source-consumption was carried out by two monitoring programs, one of them suited for OS Windows, the other for OS Linux. Both programs safe the information about procesor-work and operational memory into a text dokument which is very simple and fast way for searching the information. The measured values show charts and graphs that express the efficiency of separate OSs or, in case of need, servers of different outputs are able to handle the generated paquets and how do the alterations of the paquet generator affect the source efficiency( paquet size and paquet-sending interval).
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Control plane analysis in 4th generation mobile networks
Hajn, Pavel ; Novotný, Vít (referee) ; Krkoš, Radko (advisor)
The thesis is focused on the description of LTE system in terms of signaling on interfaces of LTE and EPC subsystems, such as UE initial network connection. The next section describes the types of diagnostic methods for mobile networks using OSS, drive testing and flow analysis. The thesis also aims at description of key performance indicators (RSRP, RSSI, etc.) and the proposal for measuring of the LTE network physical layer and the data transmission speed.
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Control plane analysis in 4th generation mobile networks
Hajn, Pavel ; Novotný, Vít (referee) ; Krkoš, Radko (advisor)
The thesis is focused on the description of LTE system in terms of signaling on interfaces of LTE and EPC subsystems, such as UE initial network connection. The next section describes the types of diagnostic methods for mobile networks using OSS, drive testing and flow analysis. The thesis also aims at description of key performance indicators (independent service QoS parameters and the KPI for the radio part of the network). Part of the network measurement includes a description of the driver settings and views for analysis. It is also described the implementation of measuring and evaluating the results.
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Server clustering techniques
Čech, Martin ; Polívka, Michal (referee) ; Pelka, Tomáš (advisor)
The work is given an analysis of Open Source Software (further referred as OSS), which allows use and create computer clusters. It explored the issue of clustering and construction of clusters. All installations, configuration and cluster management have been done on the operating system GNU / Linux. Presented OSS makes possible to compile a storage cluster, cluster with load distribution, cluster with high availability and computing cluster. Different types of benchmarks was theoretically analyzed, and practically used for measuring cluster’s performance. Results were compared with others, eg. the TOP500 list of the best clusters available online. Practical part of the work deals with comparing performance computing clusters. With several tens of computational nodes has been established cluster, where was installed package OpenMPI, which allows parallelization of calculations. Subsequently, tests were performed with the High Performance Linpack, which by calculation of linear equations provides total performance. Influence of the parallelization to algorithm PEA was also tested. To present practical usability, cluster has been tested by program John the Ripper, which serves to cracking users passwords. The work shall include the quantity of graphs clarifying the function and mainly showing the achieved results.
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Usage of OSS/FS in enterprise network
Sobotka, Ondřej ; Hošek, Jiří (referee) ; Kříž, Jiří (advisor)
This bachelor's thesis describes propose and realization of a new evidence/reclaim system. It uses only software with an available source code – licensed as Open Source or Free Software. Main purposes are to streamline and simplify common processes in service department, for example inserting, printing, editing and listing of reclaims, creating reports, automatic executing of repeated operation and etc. Among other aims of this thesis rank accessing to the reclaim database via internet and application of security rules for an access to and work with system. MySQL server was chosen as the database system, as the HTTP server was chosen Apache. Programming languages HTML, CSS, JavaScript, PHP and SQL were used for development. Theoretical observation are mentioned first followed by analyzation of the former state in the service department and sumarization of found problems. Next key part contains detailed steps solving these problems and resulting benefits.
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The OSS in Vietnam during the Second World War
Do, Phuong Thuy ; Bečka, Jan (advisor) ; Pondělíček, Jiří (referee)
The United States engagement in Vietnam began during the Second World War. With military bases established in China, the U.S. took part in fighting the Japanese troops in the Pacific theatre. When France surrendered to Nazi Germany in 1940, Japan would take over the French Indochina and the war would spread to Vietnam as well. In order to collect intelligence on Japanese targets, the Americans needed to operate secret services on the ground. After the Japanese coup de main in 1945, they would eventually partner with Ho Chi Minh and his organization Viet Minh. The Office of Strategic Services (OSS), the wartime predecessor of the CIA, provided intelligence training and equipment, while the Viet Minh would assist with valuable information on Japanese troops. To some extent, the OSS helped Ho Chi Minh and Viet Minh accede to power in Vietnam after the war.
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HelenOS sound subsystem
Veselý, Ján ; Děcký, Martin (advisor) ; Libič, Peter (referee)
The work examines options for a modern daemon centered audio stack for HelenOS. It studies four different audio architectures; ALSA, OSS, JACK, and PulseAUdio. Each of them implements different approaches to providing general purpose audio support. Champion of every approach is analyzed, its strengths and weaknesses assessed. Based on the results of the analysis, different approaches for HelenOS audio stack are examined and the most promising one implemented. Complete audio stack is implemented, including an audio device driver, and a demonstrator audio application. Direction of future work and improvements is discussed at the end.
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Flood Loss Modelling
Podlaha, Adam ; Hladný, Josef (advisor) ; Langhammer, Jakub (referee) ; Reidinger, Josef (referee)
Conclusions Floods (cunently the most frequently registered type of natural hazard) are considered tohave mosily negative and therefore important effe factors coming from three main compone *rr "";;;'"!]; r] rjrr*^*;:,r::::,,:;Throughout human history, changes have occurred I changes with a greater rever of significance nuu.ut*tn the Hazard component' However, Expo.rure and Vulnerabiliry fronts. Insurance .,",*.'Tj;::.:ť,L':i|j:'f J],.:;distributing the adverse risks of flooding. Reinsuran transfer. Flood Loss modr oraLossExceedancer.".m*;xi:;jiil:,il:il:il*::l;:TJ ighly interdisciplinary approach. using GIS and statistical analysis toors and with the support of various datasets amethodology for creating a series offlood extents (incruding a software sorution) for differentrecunence intervars was proposed' Emproying techniques described in this thesis, a set ofstochastic events can be generated and the losses associated with them carcurated. Amethodorogy dealing with the off-floodprain rosses estimation has arso been developed. Themethods introduced have been appried in rear cases and have been used in the currentinsurance market for several years. The rong term goar of devetoping flood moders is the mitigation of future flood losses. Thiscan be achieved through a better understanding of the flood |oss...
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