We derive the adjoint equations associated with the calculation of Fréchet derivatives for tomographic inversions based upon a Lagrange multiplier method. The Fréchet derivative of an objective function v(m), where m denotes the Earth model, may be written in the generic form dv Km(x) d ln m(x) d x, where d ln m dm/m denotes the relative model perturbation and Km the associated 3D sensitivity o...

This paper gives an overview of existing instantaneous frequency (IF) estimation methods divided into several major categories. One of the first IF estimation approaches was based on the spectrogram, the resolution of which is highly window size dependant. In order to improve the IF estimation accuracy, the iterative method was proposed, such that each iteration gives more accurate estimation o...

RFID (Radio Frequency Identification) recently has gained enormous attention in various industry sectors, the media, and in academic research. This paper focuses in early RFID applications in the retail supply chain. It takes a quick look at the available literature and then explains the technological issues including the need for standardization and the challenges on the data, network, and app...