Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7755

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Author: search.filters.author.Tuğlular, Tuğkan

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Now showing 1 - 7 of 7
  • Conference Object
    Citation - Scopus: 1
    Policies for Role Based Agents in Environments With Changing Ontologies
    (International Foundation for Autonomous Agents and Multiagent Systems, 2011) Tekbacak, Fatih; Tuğlular, Tuğkan; Dikenelli, Oğuz
    Software agents try to achieve the goals of roles that they have in an environment. It is supposed that the dynamic structure of role based agents can be connected with updatable domain ontologies of the environment. Ontology evolution can cause the update of agent behaviors or access restrictions to ontological elements. So regulation for the agent behaviors may be needed. Our motivation is to create a suitable policy model for agents, environments and organizations when ontologies in the environment can change.
  • Book Part
    Citation - WoS: 4
    Citation - Scopus: 8
    Advances in Model-Based Testing of Graphical User Interfaces
    (Academic Press Inc., 2017) Belli, Fevzi; Beyazıt, Mutlu; Budnik, Christof J.; Tuğlular, Tuğkan
    Graphical user interfaces (GUIs) enable comfortable interactions of the computer-based systems with their environment. Large systems usually require complex GUIs, which are commonly fault prone and thus are to be carefully designed, implemented, and tested. As a thorough testing is not feasible, techniques are favored to test relevant features of the system under test that will be specifically modeled. This chapter summarizes, reviews, and exemplifies conventional and novel techniques for model-based GUI testing.
  • Master Thesis
    Access Monitoring System for Distributed Firewall Policies
    (Izmir Institute of Technology, 2008) Çakı, Oğuzhan; Tuğlular, Tuğkan
    Internet has provided several benefits in terms of information sharing. However, Internet is an insecure environment that can cause threats to private networks. As a result, network security becomes a critical issue. One of the important tools used in network security is firewall. Firewalls protect a private network from external threats by restricting network traffic according to predefined security rules. Basically, firewalls apply these rules to each packet that passes over them. Distributed firewalls are a new approach to firewall to overcome some drawbacks of traditional firewalls. Distributed firewall design is based on the idea of enforcing the policy rules at the endpoints rather than a single entry point to network. Management of policy rules is a critical issue in both traditional and distributed firewalls. We propose a monitoring application for distributed firewall policies to keep track of actions (create, read. update, delete) performed on policy rule set. The resulting data produced by the monitoring application will be very helpful in policy management process.
  • Master Thesis
    End-To Security for Mobile Devices
    (Izmir Institute of Technology, 2004) Kayayurt, Barış; Tuğlular, Tuğkan; Tuğlular, Tuğkan
    End-to-end security has been an emerging need for mobile devices with the widespread use of personal digital assistants and mobile phones. Transport Layer Security Protocol (TLS) is an end-to-end security protocol that is commonly used in Internet, together with its predecessor, SSL protocol. By using TLS protocol in mobile world, the advantage of the proven security model of this protocol can be taken.J2ME (Java 2 Micro Edition) has been the de facto application platform used in mobile devices. This thesis aims to provide an end-to-end security protocol implementation based on TLS 1.0 specification and that can run on J2ME MIDP (Mobile Information Device Profile) environment. Because of the resource intensive public-key operations used in TLS, this protocol needs high resources and has low performance. Another motivation for the thesis is to adapt the protocol for mobile environment and to show that it is possible to use the protocol implementation in both client and server modes. An alternative serialization mechanism is used instead of the standard Java object serialization that is lacking in MIDP. In this architecture, XML is used to transmit object data.The mobile end-to-end security protocol has the main design issues of maintainability and extensibility. Cryptographic operations are performed with a free library, Bouncy Castle Cryptography Package. The object-oriented architecture of the protocol implementation makes the replacement of this library with another cryptography package easier.Mobile end-to-end security protocol is tested with a mobile hospital reservation system application. Test cases are prepared to measure the performance of the protocol implementation with different cipher suites and platforms. Measured values of all handshake operation and defined time spans are given in tables and compared with graphs.
  • Master Thesis
    Development of a Distributed Firewall Administration Tool
    (Izmir Institute of Technology, 2008) Erdoğan, Yunus; Tuğlular, Tuğkan
    Today firewalls not only guard internal computer networks but also individual personal computers against malicious and unauthorized accesses from outside. The purpose of this study is to create architecture and its corresponding application to manage distributed firewalls running on Microsoft Windows platform. Distributed Firewall Administration is about creating a management center for a network composed of the firewalls running on Microsoft Windows platform. Main important part of this work is to determine distributed firewall network topology with breadth-first search and depth-first search algorithms.The Microsoft Windows Firewall API makes it possible to programmatically manage the features of firewalls running on windows platform by allowing applications to create, enable and disable firewall exceptions. This study used the Windows Firewall API to manage the features of it. This API is only reachable using C/C++ low level programming languages.Distributed Firewall Administration Tool (DFAT) can add, modify or delete rules on the end-user firewall rule set, these rules stored on the database. This tool works on a distributed environment, there is a parent child relationship between firewalls. Parent firewalls have right to manage its child firewall.s rule set. Firewalls introduce themselves to each other with broadcast method.
  • Master Thesis
    Firewall monitoring using intrusion detection systems
    (Izmir Institute of Technology, 2005) Asarcıklı, Şükran; Tuğlular, Tuğkan
    Most organizations have intranet, they know the benefits of connecting their private LAN to the Internet. However, Internet is inherently an insecure network. That makes the security of the computer systems an imported problem. The first step of network security is firewalls. Firewalls are used to protect internal networks from external attacks through restricting network access according to the rules. The firewall must apply previously defined rules to each packet reaching to its network interface. If the application of rules are prohibited due to malfunction or hacking, internal network may be open to attacks and this situation should be recovered as fast as possible. In order to be sure about the firewall working properly, we proposed to use Intrusion Detection Systems (IDS)to monitor firewall operation. The architecture of our experimental environment is composed of a firewall and two IDSs. One IDS is between external network and firewall, while the other is between firewall and private network. Those two IDSs are invisible to the both networks and they send their information to a monitoring server, which decides, based on two observations, whether the firewall is working properly or not.
  • Master Thesis
    A Detection and Correction Approach for Overflow Vulnerabilities in Graphical User Interfaces
    (Izmir Institute of Technology, 2009) Müftüoğlu, Can Arda; Tuğlular, Tuğkan
    The objective of this thesis is to propose an approach for detecting overflow vulnerabilities such as buffer and boundary overflows by using static analysis and correcting these vulnerabilities by applying a correction mechanism which uses static code insertion. GUI is tested by specifying user interface requirements and converting this specification into an event-sequence model. Decision table notion is used for modeling the dependencies and boundary restrictions on input data and generating test cases. The test cases are applied to the GUI as inputs manually in real environment. The faults are observed. Then, the overflow vulnerability analysis tool is used to analyze the source code of the program. The deficiencies related to overflow vulnerabilities are found by static analysis. After that, the correction mechanism is applied to the deficient parts of the source code. The software is tested in real environment again. The proposed approach is observed to be successful for detecting and correcting overflow vulnerabilities in GUIs.