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Full-Text Articles in Engineering
Photolithographic Fabrication Of 3d Penrose-Like Quasi-Photonic Crystal Polymeric Templates Utilizing Lab-Made Phasemask, Faraon Torres-Lazos
Photolithographic Fabrication Of 3d Penrose-Like Quasi-Photonic Crystal Polymeric Templates Utilizing Lab-Made Phasemask, Faraon Torres-Lazos
Theses and Dissertations - UTB/UTPA
Photonic crystals (PhC) have recently become of great interest because of their potential as replacement of electronics and/or supplement to semiconductors technology. The PhC’s capability to make compact integrated optical circuits has already made possible the laboratory manufacture of an array of different types of optical waveguides, cavities and filters. The work presented here aimed to simultaneously fabricate a 3D-PhC templates employing six-beam holographic lithography. The basic procedures included recording gratings using interference field of laser sources in a photoresist coating on a glass substrate. The manufacturing method utilized only one optical element, a phasemask, drastically reducing the complexity of …
Experimental Evaluation Of Select Servers And Firewalls Under Denial Of Service Security Attacks, Raja Sekhar Reddy Gade
Experimental Evaluation Of Select Servers And Firewalls Under Denial Of Service Security Attacks, Raja Sekhar Reddy Gade
Theses and Dissertations - UTB/UTPA
Internet security requires newer prevention mechanisms to be implemented on web-servers and routers. Firewall/Intrusion Prevention mechanisms (IPS) can be deployed on host servers or routers as an added line of defense against Internet attacks. In this thesis, we evaluate performance of security mechanisms provided by these devices against Distributed Denial of Service (DDoS) attacks. The host based firewalls on Windows servers-2003 and 2008 were evaluated. In this thesis, we also evaluated Juniper Networks Netscreen-5GT firewall/IPS, and Cisco ASA-5510/IPS that are used in protecting web-servers against DDoS attacks. It was found that the host based firewalls and protection mechanisms on the …
An Improved Wideband Vivaldi Antenna Design, Fang Chen
An Improved Wideband Vivaldi Antenna Design, Fang Chen
Theses and Dissertations - UTB/UTPA
The objectives of this thesis are to 1) determine how Vivaldi antenna parameters affect the performance and 2) design a Vivaldi antenna with improved overall performance over existing designs. The methodology is to divide the Vivaldi antenna into two parts consisting of microstrip-to-slotline transition and tapered curve part. This has great advantages in finding the relationships between the different antenna parameters and the antenna performance. By combining the methods of improving the impedance- and usable gain bandwidth concluded by the parameter study on the two individual parts, a final Vivaldi antenna design with 10:1 bandwidth is achieved in terms of …
Security Vulnerability Evaluation Of Popular Personal Firewalls And Operating Systems, Sirisha Surisetty
Security Vulnerability Evaluation Of Popular Personal Firewalls And Operating Systems, Sirisha Surisetty
Theses and Dissertations - UTB/UTPA
In this thesis, experimental evaluation of security vulnerabilities has been performed under DoS attacks for popular personal firewalls from McAfee, Norton and Kaspersky; and for operating systems namely Apple’s Leopard and SnowLeopard, and Microsoft’s Windows XP and Windows 7. Our experimental results show that the firewalls and operating systems behave differently under a given DoS attack. Some of the firewalls crashed under certain DoS attacks especially when they were configured to prevent and block packets belonging to such attacks. Operating systems evaluated in this thesis were also found to have different built-in security capabilities, and some of them even crashed …