In this paper, we present a technique for embedding digital watermarks into digital audio signals. Watermarking is a technique used to label digital media by hiding copyright or other information in the underlying data. In the case of digital audio, the main constraint is the tradeoff between robustness and imperceptibility, as hearing is one of the most sensitive human senses. In our method, t...

We present a method of helical long-period fiber grating (H-LPFG) fabrication by use of a CO2 laser for use as an optical torque sensor. A conventional optical fiber grating has periodic vertical index changes along its fiber axis, but a H-LPFG has a screw-type index modulation. The helical index modulation is obtained with the asymmetric index change caused by a single-side laser beam exposure...

Quantization index modulation (QIM) methods, a class of digital watermarking and information embedding methods, achieve very e cient trade-o s among the amount of embedded information (rate), the amount of embedding-induced distortion to the host signal, and the robustness to intentional and unintentional attacks. For example, we show that against independent additive Gaussian attacks, which ar...

Millimeter wave communication is eminently suitable for high-rate wireless systems, which may be beneficially amalgamated with intelligent reflecting surfaces (IRS), while relying on beam-index modulation. Explicitly, we propose three different architectures based IRSs modulation in millimeter communication. Our schemes are capable of eliminating the detrimental line-of-sight blockage frequenci...

A model for volume hologram formation in thick dichromated gelatin fih-ns is given. Using the model and a few basic film measurements, we can quantify the index modulation vs. exposure curve. The effects of saturation and dynamic absorption increase during exposure are considered in the generation of spatial harmonics. The effects of exposure with non-unity beam-ratio and multiple incoherent ex...

We address light propagation in couplers with longitudinal biharmonic modulation of refractive index in neighboring channels. While simplest single-frequency out-of-phase modulation allows suppression of coupling for a strictly defined set of resonant frequencies, the addition of modulation on multiple frequencies dramatically modifies the structure of resonances. Thus, additional modulation on...

This paper proposes a new topology namely Improved Current Fed Switched Inverter which is derived from the current fed switched inverter. The new topology improves the value of modulation index from its previous topology where the value of modulation index was restricted. The system is suitable for the renewable applications since it draws continuous input current. Single stage high boost inver...

conclusions caffeine has a potential role for pain modulation. current evidence on caffeine use for migraine and terminal stage cancer is not well-established. future studies should address the use of caffeine alone for different types of pain with dose escalation and standardization of outcome measurement. evidence acquisition the data on caffeine as an adjuvant therapy or as a main component ...

Orthogonal frequency division multiplexing with index modulation (OFDM-IM) has attracted considerable interest recently. The technique uses the subcarrier indices as a source of information. In FBMC system, doubledispersive channels lead to inter-carrier interference (ICI) and/or inter-symbol interference (ISI), which are caused by the neighboring symbols in the frequency and/or time domain. Wh...