سیدعلیرضا سیدین

دانشگاه فردوسی مشهد - دانشکده مهندسی

[ 1 ] - تصویرسازی در سونار روزنه مصنوعی معکوس چندپایه با استفاده از روش پس‌تابش فیلترشده

تصویربرداری از اهداف متحرک زیر آب با استفاده از سونار روزنه مصنوعی معکوس امکان‌پذیر است اما علاوه بر مشکلات کاربردی که در به‌کارگیری رادارهای روزنه مصنوعی معکوس موجود است، شرایط خاص محیط آب و انتشار امواج صوتی در آن، تصویربرداری را به امری دشوار و پرچالش تبدیل کرده است. در این مقاله روشی پیشنهاد می‌گردد که با استفاده از ایده سونار روزنه مصنوعی معکوس چندپایه و با فرض قرارگیری در آب‌های کم‌عمق که...

[ 2 ] - A Study on Properties of Dempster-Shafer Theory to Probability Theory transformations

In this paper, five conditions that have been proposed by Cobb and Shenoy are studied for nine different mappings from the Dempster-Shafer theory to the probability theory. After comparing these mappings, one of the considerable results indicates that none of the mappings satisfies the condition of invariance with respect to the marginalization process. In more details, the main reason for this...

[ 3 ] - Analysis and Improving the Security of the Scalar Costa Scheme against Known Message Attack

Unintentional attacks on watermarking schemes lead to degrade the watermarking channel, while intentional attacks try to access the watermarking channel. Therefore, watermarking schemes should be robust and secure against unintentional and intentional attacks respectively. Usual security attack on watermarking schemes is the Known Message Attack (KMA). Most popular watermarking scheme with stru...

[ 4 ] - A Secure Chaos-Based Communication Scheme in Multipath Fading Channels Using Particle Filtering

In recent years chaotic secure communication and chaos synchronization have received ever increasing attention. Unfortunately, despite the advantages of chaotic systems, Such as, noise-like correlation, easy hardware implementation, multitude of chaotic modes, flexible control of their dynamics, chaotic self-synchronization phenomena and potential communication confidence due to the very dynami...

[ 5 ] - Nonlinear Multiuser Receiver for Optimized Chaos-Based DS-CDMA Systems

Chaos based communications have drawn increasing attention over the past years. Chaotic signals are derived from non-linear dynamic systems. They are aperiodic, broadband and deterministic signals that appear random in the time domain. Because of these properties, chaotic signals have been proposed to generate spreading sequences for wide-band secure communication recently. Like conventional DS...