32 research outputs found

    Moat: A Virtual Private Network Appliance and Services Platform

    Get PDF
    Vakava onnettomuus, sairaus tai aivoinfarkti voi aiheuttaa tilan, jossa ihminen ei pysty liikkumaan eikä puhumaan. Usein kyky liikuttaa silmiä kuitenkin säilyy, vaikka ihminen olisi muuten täysin halvaantunut. Silmien liikettä ja katseen suuntaa voidaan tällöin hyödyntää kommunikaatiossa. Lääkäri voi esimerkiksi pyytää potilasta katsomaan ylös myöntymisen merkiksi. Vammautuneen henkilön eteen voidaan myös asettaa läpinäkyvä kommunikaatiotaulu, johon on kiinnitetty kuvia tai kirjaimia. Taulun avulla on mahdollista muodostaa sanoja ja lauseita katsomalla kirjaimia yksi kerrallaan. Keskustelukumppani tulkitsee viestin seuraamalla kommunikaatiotaulun toiselta puolelta henkilön katseen suuntaa. Kommunikaatiotaulua kehittyneempi menetelmä on katseenseurantalaite, joka mahdollistaa itsenäisen kirjoittamisen ja tietokoneen ohjaamisen katseella. Katseenseurantalaitteessa on tyypillisesti videokamera, joka kuvaa käyttäjän silmän liikkeitä. Tietokoneen ohjelma tulkitsee katseen suunnan ja päättelee, mihin kohtaan näytöllä käyttäjä kulloinkin katsoo. Yksinkertaisimmillaan näytöllä on kuva näppäimistöstä ja käyttäjä kirjoittaa silmillään katsomalla näppäimistön kirjaimia. Jotta tietokone erottaisi, milloin käyttäjä haluaa valita katsomansa kohteen, käyttäjän pitää katsoa kirjainta riittävän pitkään. Pitkä viive auttaa ehkäisemään virhevalintoja, mutta hidastaa samalla kommunikaatiota. Katseeseen perustuvia tekstinsyöttöjärjestelmiä on kehitetty muutaman vuosikymmenen ajan ja niiden käyttö kommunikaation apuvälineenä on yleistynyt viime vuosina. Katseella kirjoittamista ei kuitenkaan ole juurikaan tutkittu. Väitöskirja tarjoaa perusteellisen katsauksen aiheen tutkimukseen ja eri tapoihin käyttää katsetta tekstin tuottamiseen ja kommunikointiin. Työssä esitellään uusia tapoja tehostaa katseella kirjoittamista yksinkertaisten käyttöliittymäratkaisujen avulla. Väitöskirja tarjoaa tutkimustuloksiin perustuvia konkreettisia esimerkkejä ja ohjeita siitä, kuinka katseella kirjoittamisen miellyttävyyttä ja nopeutta voidaan parantaa huolellisen käyttöliittymäsuunnittelun avulla. Käyttäjätutkimukset osoittavat, että esimerkiksi ohjelman tarjoama palaute vaikuttaa merkittävästi kirjoitusnopeuteen ja virheiden määrään. Vastaavasti mahdollisuus säätää valintaan vaadittavaa viivettä mahdollistaa katsekirjoituksen nopean ja tehokkaan oppimisen.Text entry by eye gaze is used by people with severe motor disabilities. An eye tracking device follows the user s eye movements, and a computer program analyzes the gaze behavior. To type by gaze, the user typically points at the characters on an on-screen keyboard by looking at them and selects them by means of dwell time, a prolonged gaze that separates an intentional command from casual viewing. The basic methods for producing text by gaze have been researched and in real-world use since the early 1980s; however, the design issues have not been studied in detail. Until recently, assistive eye tracking systems were used mostly by a small number of people who were totally paralyzed and for whom gaze control was a necessity and the only option. The technology and its usability have improved considerably, and several new systems have appeared on the market, making the technology available for a much wider group of users with varying need and abilities. Today, the eye tracker can be considered an optional assistive device worth considering since it provides easy and fast access to information technology by gaze alone. This thesis provides an extensive review of the research conducted in the area of gaze-based text entry. It summarizes results from several experiments that study various aspects of text entry by gaze. Results show that small improvements in the interface design can lead to significant improvements in user performance and satisfaction. For example, adding a simple "click" that confirms the selection by gaze can significantly improve the text entry speed over that of plain visual feedback. The improvement is small, but the effect accumulates in the repetitive task of text entry. An overview of different design solutions and guidelines derived from the research results are given. It is hoped that the thesis will provide a useful starting point for developers, researchers, and assistive technology professionals wishing to gain deeper insight into gaze-based text entry

    Debian Clusters for Education and Research: The Missing Manual

    Get PDF

    The Use of Firewalls in an Academic Environment

    No full text

    The effective combating of intrusion attacks through fuzzy logic and neural networks

    Get PDF
    The importance of properly securing an organization’s information and computing resources has become paramount in modern business. Since the advent of the Internet, securing this organizational information has become increasingly difficult. Organizations deploy many security mechanisms in the protection of their data, intrusion detection systems in particular have an increasingly valuable role to play, and as networks grow, administrators need better ways to monitor their systems. Currently, many intrusion detection systems lack the means to accurately monitor and report on wireless segments within the corporate network. This dissertation proposes an extension to the NeGPAIM model, known as NeGPAIM-W, which allows for the accurate detection of attacks originating on wireless network segments. The NeGPAIM-W model is able to detect both wired and wireless based attacks, and with the extensions to the original model mentioned previously, also provide for correlation of intrusion attacks sourced on both wired and wireless network segments. This provides for a holistic detection strategy for an organization. This has been accomplished with the use of Fuzzy logic and neural networks utilized in the detection of attacks. The model works on the assumption that each user has, and leaves, a unique footprint on a computer system. Thus, all intrusive behaviour on the system and networks which support it, can be traced back to the user account which was used to perform the intrusive behavior

    A risk analysis and risk management methodology for mitigating wireless local area networks (WLANs) intrusion security risks

    Get PDF
    Every environment is susceptible to risks and Wireless Local Area Networks (WLANs) based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard are no exception. The most apparent risk of WLANs is the ease with which itinerant intruders obtain illicit entry into these networks. These intrusion security risks must therefore be addressed which means that information security risk analysis and risk management need to be considered as integral elements of the organisation’s business plan. A well-established qualitative risk analysis and risk management methodology, the Operationally Critical Threat Asset and Vulnerability Evaluation (OCTAVE) is selected for conducting the WLAN intrusion security risk analysis and risk management process. However, the OCTAVE risk analysis methodology is beset with a number of problems that could hamper a successful WLAN intrusion security risk analysis. The ultimate deliverable of this qualitative risk analysis methodology is the creation of an organisation-wide protection strategy and risk mitigation plan. Achieving this end using the OCTAVE risk analysis methodology requires an inordinate amount of time, ranging from months to years. Since WLANs are persistently under attack, there is a dire need for an expeditious risk analysis methodology. Furthermore, the OCTAVE risk analysis methodology stipulates the identification of assets and corresponding threat scenarios via a brainstorming session, which may be beyond the scope of a person who is not proficient in information security issues. This research was therefore inspired by the pivotal need for a risk analysis and risk management methodology to address WLAN intrusion attacks and the resulting risks they pose to the confidentiality, integrity and availability of information processed by these networks. CopyrightDissertation (MSc (Computer Science))--University of Pretoria, 2006.Computer Scienceunrestricte
    corecore