Conjugated polyynes are a class of species of diverse and increasing interest. Length-scrambling and substituent scrambling reaction energies were examined using ab initio quantum chemistry calculations to investigate issues concerning the energetic effects of the molecular ends (substituent communication). Computations were performed for the parent, monohalogenated, and dihalogenated (F, Cl, B...

This paper is concerned with a randomized OFDM (R-OFDM) scheme. The basic principle is to apply a scrambling operation to several OFDM frames. With a proper design strategy, the scrambling operation will not affect intra-cell orthogonality of OFDM (even considering multi-path effect). For signals from different cells, mutually random scramblings are used to reduce their correlation. This allevi...

It was Ross (1967) who gave the apt name "scrambling" to these types of free word order permutation. Unlike Japanese and Dutch, English does not allow scrambling. Thus, for example, permuting the subject and the object in English would fundamentally alter the meaning of the sentence (John saw Mary; Mary saw John). Within the VP, English does not allow the type of word-order choices we saw above...

Based on blocked image scrambling encryption, this study presents a new image encryption algorithm by introducing chaos theory. This algorithm firstly makes spatial scrambling based on image blocking in order to interrupt pixel position, then furthering this interruption through Arnold Mapping in the chaos and transforms pixel RGB color space through optimized Arnold Mapping. After this process...

In this paper, a tone mapping algorithm is proposed to produce LDR (Limited Dynamic Range) images from HDR (High Dynamic Range) images. In the approach, nonlinear functions are applied to compress the dynamic range of HDR images. Security tools will be then applied to the resulting LDR images and their effectiveness will be tested on the reconstructed HDR images. Three specific examples of secu...

In this paper we present a system for preserving the privacy of individuals in video sequences by obfuscation of facial appearance, so as to render recorded people unrecognizable. Therefore we address the following two problems: automatic face detection and scrambling of face region. A multi-resolution access control scheme is used in order to decrease the visual quality of regions containing f...

OFDM scrambling is one of the most popular techniques for secure communication. This paper proposes a new scrambling technique based on random permutation with the pseudo random binary generator to improve the performance of OFDM scrambler. To measure the intelligibility of speech, speech transmission index (STI) and common intelligibility scale (CIS) are used. The Bit Error Rate (BER) and Sign...

In this paper, we present a novel speech encryption algorithm based on four level of hash based encryption. Our approach integrates a modified time domain scrambling scheme with an amplitude scrambling method which masks the speech signal with algorithmic based noise by specific mixing. In this, we use different algorithm to encrypt the speech signal at different levels i.e. we encrypt the orig...

This paper proposes a novel pixel-based scrambling scheme to protect, in an efficient and secure way, the distribution of digital medical images. To provide an efficient encryption of a large volume of digital medical images, the proposed system uses simple pixel level XOR operation for image scrambling in an innovative way such that structural parameters of the encryption scheme have become a ...

This paper proposes application-specific instructions and their bit manipulation unit (BMU), which efficiently support scrambling, convolutional encoding, puncturing, interleaving, and bit stream multiplexing. The proposed DSP employs the BMU supporting parallel shift and XOR (exclusive-OR) operations and bit insertion/extraction operations on multiple data. The proposed architecture has been m...