Coding pulse sequences using a combination of factorial pulse coding and arithmetic coding

Author(s):  
Udar Mittal ◽  
Tenkasi V. Ramabadran ◽  
James P. Ashley
2001 ◽  
Vol 30 (5) ◽  
pp. 276-284 ◽  
Author(s):  
M Sakamoto ◽  
T Sasano ◽  
S Higano ◽  
S Takahashi ◽  
T Nagasaka ◽  
...  

2017 ◽  
Vol 49 (12) ◽  
pp. 1-13 ◽  
Author(s):  
Vladimir N. Maksymovych ◽  
Oleg I. Harasymchuk ◽  
Marya N. Mandrona
Keyword(s):  

2017 ◽  
Vol 13 (10) ◽  
pp. 6552-6557
Author(s):  
E.Wiselin Kiruba ◽  
Ramar K.

Amalgamation of compression and security is indispensable in the field of multimedia applications. A novel approach to enhance security with compression is discussed in this  research paper. In secure arithmetic coder (SAC), security is provided by input and output permutation methods and compression is done by interval splitting arithmetic coding. Permutation in SAC is susceptible to attacks. Encryption issues associated with SAC is dealt in this research method. The aim of this proposed method is to encrypt the data first by Table Substitution Box (T-box) and then to compress by Interval Splitting Arithmetic Coder (ISAC). This method incorporates dynamic T-box in order to provide better security. T-box is a method, constituting elements based on the random output of Pseudo Random Generator (PRNG), which gets the input from Secure Hash Algorithm-256 (SHA-256) message digest. The current scheme is created, based on the key, which is known to the encoder and decoder. Further, T-boxes are created by using the previous message digest as a key.  Existing interval splitting arithmetic coding of SAC is applied for compression of text data. Interval splitting finds a relative position to split the intervals and this in turn brings out compression. The result divulges that permutation replaced by T-box method provides enhanced security than SAC. Data is not revealed when permutation is replaced by T-box method. Security exploration reveals that the data remains secure to cipher text attacks, known plain text attacks and chosen plain text attacks. This approach results in increased security to Interval ISAC. Additionally the compression ratio  is compared by transferring the outcome of T-box  to traditional  arithmetic coding. The comparison proved that there is a minor reduction in compression ratio in ISAC than arithmetic coding. However the security provided by ISAC overcomes the issues of compression ratio in  arithmetic coding. 


1993 ◽  
Author(s):  
Krystyna Ohnesorge ◽  
Peter Stucki ◽  
Hartwig Thomas

Author(s):  
Ana Maria Ariciu ◽  
David H. Woen ◽  
Daniel N. Huh ◽  
Lydia Nodaraki ◽  
Andreas Kostopoulos ◽  
...  

Using electron spins within molecules for quantum information processing (QIP) was first proposed by Leuenberger and Loss (1), who showed how the Grover algorithm could be mapped onto a Mn12 cage (2). Since then several groups have examined two-level (S = ½) molecular spin systems as possible qubits (3-12). There has also been a report of the implementation of the Grover algorithm in a four-level molecular qudit (13). A major challenge is to protect the spin qubit from noise that causes loss of phase information; strategies to minimize the impact of noise on qubits can be categorized as corrective, reductive, or protective. Corrective approaches allow noise and correct for its impact on the qubit using advanced microwave pulse sequences (3). Reductive approaches reduce the noise by minimising the number of nearby nuclear spins (7-11), and increasing the rigidity of molecules to minimise the effect of vibrations (which can cause a fluctuating magnetic field via spin-orbit coupling) (9,11); this is essentially engineering the ligand shell surrounding the electron spin. A protective approach would seek to make the qubit less sensitive to noise: an example of the protective approach is the use of clock transitions to render spin states immune to magnetic fields at first order (12). Here we present a further protective method that would complement reductive and corrective approaches to enhancing quantum coherence in molecular qubits. The target is a molecular spin qubit with an effective 2S ground state: we achieve this with a family of divalent rare-earth molecules that have negligible magnetic anisotropy such that the isotropic nature of the electron spin renders the qubit markedly less sensitive to magnetic noise, allowing coherent spin manipulations even at room temperature. If combined with the other strategies, we believe this could lead to molecular qubits with substantial advantages over competing qubit proposals.<br>


2020 ◽  
Vol 65 (9) ◽  
pp. 1416-1420
Author(s):  
Yu. V. Bogachev ◽  
A. V. Nikitina ◽  
V. V. Frolov ◽  
Ya. Yu. Marchenko ◽  
B. P. Nikolaev

2017 ◽  
Vol 118 (13) ◽  
Author(s):  
Genko T. Genov ◽  
Daniel Schraft ◽  
Nikolay V. Vitanov ◽  
Thomas Halfmann

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