Aligning block permutation methods for topology transformation on computational grids

2011 ◽  
Vol 61 (3) ◽  
pp. 545-559
Author(s):  
Uei-Ren Chen ◽  
Woei Lin
Keyword(s):  
Computational Grids ◽  
Permutation Methods ◽  
Block Permutation

Table Substitution Box Method for Increasing Security in Interval Splitting Arithmetic Coding

2017 ◽  
Vol 13 (10) ◽  
pp. 6552-6557
Author(s):  
E.Wiselin Kiruba ◽  
Ramar K.
Keyword(s):  
Compression Ratio ◽  
Arithmetic Coding ◽  
Substitution Box ◽  
Plain Text ◽  
T Box ◽  
Novel Approach ◽  
Permutation Methods ◽  
Message Digest ◽  
Box Method ◽  
Arithmetic Coder

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. 

Techniques for the visual evaluation of computational grids

1993 ◽  
Author(s):  
KELLY PARMLEY ◽  
JOHN DANNENHOFFER, III ◽  
NIGEL WEATHERILL
Keyword(s):  
Computational Grids ◽  
Visual Evaluation

Resource allocation on computational grids using a utility model and the knapsack problem

2009 ◽  
Vol 25 (1) ◽  
pp. 35-50 ◽  
Author(s):  
Daniel C. Vanderster ◽  
Nikitas J. Dimopoulos ◽  
Rafael Parra-Hernandez ◽  
Randall J. Sobie
Keyword(s):  
Resource Allocation ◽  
Knapsack Problem ◽  
Computational Grids ◽  
Utility Model

scholarly journals Multiscale Coupling of Transcranial Direct Current Stimulation to Neuron Electrodynamics: Modeling the Influence of the Transcranial Electric Field on Neuronal Depolarization

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Edward T. Dougherty ◽  
James C. Turner ◽  
Frank Vogel
Keyword(s):  
Electric Field ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Three Dimensional ◽  
Human Head ◽  
Multiscale Model ◽  
Medical Intervention ◽  
Medical Community ◽  
Computational Grids ◽  
Direct Current Stimulation

Transcranial direct current stimulation (tDCS) continues to demonstrate success as a medical intervention for neurodegenerative diseases, psychological conditions, and traumatic brain injury recovery. One aspect of tDCS still not fully comprehended is the influence of the tDCS electric field on neural functionality. To address this issue, we present a mathematical, multiscale model that couples tDCS administration to neuron electrodynamics. We demonstrate the model’s validity and medical applicability with computational simulations using an idealized two-dimensional domain and then an MRI-derived, three-dimensional human head geometry possessing inhomogeneous and anisotropic tissue conductivities. We exemplify the capabilities of these simulations with real-world tDCS electrode configurations and treatment parameters and compare the model’s predictions to those attained from medical research studies. The model is implemented using efficient numerical strategies and solution techniques to allow the use of fine computational grids needed by the medical community.

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