Compensation of UUV magnetic field interference based on ridge estimation

Active compensation of magnetic field distortions based on vector spherical harmonics field description

fabrication of new ion sensitive field effect transistors (isfet) based on modification of junction-fet for analysis of hydronium, potassium and hydrazinium ions

a novel and ultra low cost isfet electrode and measurement system was designed for isfet application and detection of hydronium, hydrazinium and potassium ions. also, a measuring setup containing appropriate circuits, suitable analyzer (advantech board), de noise reduction elements, cooling system and pc was used for controlling the isfet electrode and various characteristic measurements. the t...

Magnetic Sensor Operation Onboard a UUV: Magnetic Noise Investigation using a Total-Field Gradiometer

To operate a magnetic sensor on board an Unmanned Underwater Vehicle (UUV), it is necessary to provide a means for compensating magnetic noise from a variety of sources. In previous applications involving passively towed platforms, the noise arises from the magnetic fields due to eddy currents and magnetic polarization changes occurring due to rotation of the platform in the earth’s magnetic fi...

UKF-based Parameter Estimation Method for Precise UUV Navigation

This paper proposes a parameter estimation method for improving the navigation accuracy of an unmanned underwater vehicle, which is equipped with a doppler, a gyro, a depth sensor and a GPS, using an Unscented Kalman Filter (UKF). The error sources are analyzed, and then a kinematical model is constructed accordingly. Using an UKF, the doppler scaling factor and the rotational alignment offset ...

study of hash functions based on chaotic maps

توابع درهم نقش بسیار مهم در سیستم های رمزنگاری و پروتکل های امنیتی دارند. در سیستم های رمزنگاری برای دستیابی به احراز درستی و اصالت داده دو روش مورد استفاده قرار می گیرند که عبارتند از توابع رمزنگاری کلیددار و توابع درهم ساز. توابع درهم ساز، توابعی هستند که هر متن با طول دلخواه را به دنباله ای با طول ثابت تبدیل می کنند. از جمله پرکاربردترین و معروف ترین توابع درهم می توان توابع درهم ساز md4, md...