1 Absolute frequency measurement of Mid Infrared secondary frequency standard at BNM-LPTF G. D. Rovera, , Member, IEEE and O. Acef Abstract|An absolute frequency measurement of a CO2=OsO4 secondary frequency standard, operating in the mid infrared, is reported. A brief description of the measurement chain linking this standard to a hydrogen maser evidences the critical points. The measured freq...

Optical clocks have been the focus of science and technology research areas due to their capability to provide highest frequency accuracy and stability to date. Their superior frequency performance promises significant advances in the fields of fundamental research as well as practical applications including satellite-based navigation and ranging. In traditional optical clocks, ultrastable opti...

In this paper, multi-objective optimization of railway wheel web profile using bidirectional evolutionary structural optimization (BESO) algorithm is investigated. Using a finite element software, static analysis of the wheel based on a standard load case, and its modal analysis for finding the fundamental natural frequency is performed. The von Mises stress and critical frequency as the proble...

seismic attribute is a quantitative measure of an interested seismic characteristic. there are several seismic attributes. in recent years, time-frequency (tf) attributes have been developed which to reach them, tf analyzing of seismic data is required. a high resolution tf representation (tfr) can yield more accurate tf attributes. there are several tfr methods including short-time fourier tra...