Global Navigation Satellite Systems (GNSS) have become an essential part of maritime navigation, in particular to improve situational awareness and vessel traffic management. The dependence on GNSS creates vulnerability for shipping. Driven by this vulnerability, the desire a backup system navigation has been emerging. VHF Data Exchange System (VDES) standard provides communication capabilities...

VDES R-Mode aims at providing a contingency maritime positioning and navigation system when the operation of Global Navigation Satellite Systems (GNSS) is disrupted. However, R-Mode, similarly to GNSS, can itself also be subject different types attacks, such as jamming or spoofing. In this paper, we evaluate vulnerabilities discuss effectiveness cost countermeasures. The outcome cost-benefit an...

Ejection fraction is the most important indicator of heart failure. Angiography , is a standard method to demonstrate ejection fraction but it is invasive. Therefore determination of sensitivity and specificity of echocardiography versus angiography is a good guidance for physicians. A total number of 50 patients were enrolled in a prospective study. Two dimension and M-Mode echocardiography...