Anomaly-based network intrusion detection methods

The article deals with detection of network anomalies. Network anomalies include everything that is quite different from the normal operation. For detection of anomalies were used machine learning systems. Machine learning can be considered as a support or a limited type of artificial intelligence. A machine learning system usually starts with some knowledge and a corresponding knowledge organization so that it can interpret, analyse, and test the knowledge acquired. There are several machine learning techniques available. We tested Decision tree learning and Bayesian networks. The open source data-mining framework WEKA was the tool we used for testing the classify, cluster, association algorithms and for visualization of our results. The WEKA is a collection of machine learning algorithms for data mining tasks

Modely operačních zesilovačů pro simulační programy elektronických obvodů

Import 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta elektrotechniky a informatiky. Katedra (454) elektronik

Variant Plans of Connection of the New 110/22 kV Substation, Opava into Medium Voltage Network

Import 11/07/2012Tato diplomová práce se zabývá problematikou zapojení nové transformátorové stanice 110/22 kV do stávající sítě vysokého napětí města Opavy a jeho okolí. V první části práce je popsána základní teorie elektrických sítí včetně jedné z možných metod výpočtu ustáleného chodu elektrických sítí. V jedné z dalších kapitol je stručně popsán výpočtový program Daisy Bizon, ve kterém probíhaly výpočty ustáleného chodu sítě. Jedna z části práce se zabývá popsáním stávajícího stavu sítě 22 kV oblasti Opavy včetně výpočtu ustáleného chodu sítě se zaměřením na výkonovou bilanci sítě. Hlavní část práce se zabývá napojením dvou variant nových transformátorových stanic do stávající sítě. Pro obě varianty je navrženo umístění nové stanice, návrh napojení nových kabelových vedení do stávající sítě včetně návrhu provozního zapojení. Pro každou variantu je proveden výpočet ustáleného chodu sítě, kde jsou popsány výkonové, napěťové i proudové poměry v síti. Výpočty ustáleného chodu sítě jsou doplněny o výpočty zkratových poměrů na vybraných DTS v síti. V závěru práce je ekonomické zhodnocení obou navržených variant, kde jsou stanoveny investiční náklady a také jsou vyčísleny možné úspory po zapojení nových transformátorových stanic.This Thesis deals with integration of a new transformer substation of 110/22 kV into an existing medium voltage network of the Opava town and its surroundings. The first chapter describes the basic theory of electrical power systems including one of the possible methods of calculation of steady runnig conditions of electrical power systems. One of the following chapters breafly describes calculating programme Daisy Bizon in which calculations of steady running conditions were made. The following chapters deal with an existing state of 22 kV are of Opava town including a calculation of steady running conditions with alignment to performance balance of the power system. The main chapter of my Thesis describes a connection of two variations of transformer substations to the existing system. Each variation includes locating of the new power station, suggestion of connection of new underground lines to the current system including a proposal of operational connection.There is a calculation for each steady running conditions, these include wattage, voltage and current ratio in the electrical power system. Calculations of short circuit ration have been added to the calculations of the steady running conditions on chosen DTS in the electrical power station. The resume of the Thesis there is an economical evaluation, including investments and possible savings after connection of the new transformer substations.410 - Katedra elektroenergetikyvýborn

Realization of measuring terminal of cartridge fuses

Import 29/09/2010Bakalářská práce pojednává o patronových pojistkách nízkého napětí, jakožto o jednom ze základních elektrických přístrojů určených k jištění elektrických obvodů. První část práce je zaměřena na teorii pojistek. Jsou zde jednotlivě popsány jejich základní části, dále jsou uvedeny jednotlivé konstrukční typy pojistek a v neposlední řadě je vysvětlena jejich funkce. V druhé části je popsán návrh měřícího pracoviště pro měření patronových pojistek a jeho praktická realizace. Poslední část práce je věnována samotnému měření vypínacích charakteristik. Je zde popsán návrh jednoho z možných způsobu jejich měření. Tato část je doplněna o výsledky zkušebního měření provedeného pro ověření funkčnosti přípravku a hlavně zvoleného způsobu měření.The Bachelor thesis deals with low-voltage patron fuses as one of the essential electrical appliances for protection of electrical circuits. The first part is focused on theory of fuses. Their individual parts are described here, as well as their various parts and last but not least is their function. The second part describes the design of a workplace for measuring of patron fuses and their practical realization. The last part is devoted to the measurement of tripping characteristics. I describe the application of one possible measuring method. This part is also filled with the results of the testing measuring to verify the functionality of the product and especially the chosen measuring method.Prezenční451 - Katedra elektroenergetikyvelmi dobř

Praktikum komunikačních sítí I : návody na praktická cvičení

OstravaE-vyuk

Objective assessment of IP video calls with Asterisk

The paper deals with an objective assessment of IP video calls transmission over GSM and UMTS networks. Video transmission is affected by many factors in mobile network. Among these factors belong packet loss, latency and transmission rate of the mobile network. Network properties were simulated by Simena network simulator. Our team have developed a unique technique for finding defects in video appearing in video calls. This technique is built on modified Asterisk SW PBX with enabled video recording and playback functions. Transmitted video files are compared with original video file by means of size of transmitted video file and in-video-defects. We are using MSU VQMT software for finding in video defects; more precisely we are using VQM method for comparing two video sources

Video files recording and playback with VoiceXML

The paper deals with SW PBX Asterisk and with features supporting video calls but our primary object is not switching video calls but their automatic recording and replaying. Asterisk is open source telephone exchange which brings capability for audio and video calls but does not allow recording and playback of video files. We have implemented these capabilities and our solution is designed for customers using mobile smartphones. End-users can record a video directly on server. The video files are saved in a directory and a list of these files is generated. Names on the list are read to users by means of the speech synthesis, and subsequently the DTMF key input is used to make the choice. We applied VoiceXML for this purpose and the Interactive voice response as a tool enabling browsing in the directory and playback the selected video. Nowadays, we record video on memory card inside mobile phone but our presented solution offers an option to store the video on server in real-time, for end-user is simple to make a call and video is being automatically recorded.Scopus35435

Multimedia services in Asterisk based on VoiceXML

The paper deals with multimedia services that cooperate with the Asterisk, as the communication server. Asterisk supports many services and we focused on the services that are not supported by native Asterisk. These services include recording and playback of video files, SOAP protocol support, VoiceXML and user location information. We put together all these services and created a comprehensive system. Its primary roles are performed by Asterisk. Our system enables users to save recorded video files directly to the server. Subsequently, they can replay their own videos or someone else’ files. Video files or IP cameras are easily selected by dialling a specific number. A video transmission similar to a video call is then automatically established. In our solution, the management provided by a web services server that uses SOAP protocol. User applications can use this SOAP interface to connect to Asterisk. The project is aimed in particular at users equipped with mobile end-user devices; certain services have been explicitly designed for these users. Transmission in mobile networks is limited in terms of transmission rates and latency. We defined limits for transmitting video streams in mobile networks.Scopus5586585

The interactions of SOAP-based web services for recording and replaying video files

The paper deals with the extended capability of a multimedia server to control a video transaction remotely. The presented paper is a result of applied research and is a contribution into the INDECT portal which integrates the interactions of SOAP-based web services. The project aims at developing the tools for enhancing the security of citizens and protecting the confidentiality of recorded and stored information and is a part of the 7th FP EU. We describe a multimedia handling controlled by the client application via web services.We have developed JAVA based software that allows remote control of SW PBX Asterisk through web services and AMI interface. Video files are recorded by smartphones and saved in a repository on the server. The list of stored files is generated automatically and users can replay a particular video file from the server. The names in this list are read to users by means of a speech synthesis. Subsequently, DTMF key input is used to enable making the right choice.Scopu

Remote control of asterisk via web services

The paper deals with remote control of the Asterisk SW PBX with Web Services. Our remote control of Asterisk is web based which means that it interacts with Web Service client or with specific application which uses SOAP protocol. Developing of our remote control proceeded in JAVA language and we used Asterisk-Java libraries. We also applied Asterisk AMI interface for cooperating with our commands. AMI interface has some limitations so we implemented CLI controlling over SSH, too.Scopu