Sharif Digital Repository

The development of extremely-constrained embedded systems having sensitive nodes such as RFID tags and nanosensors necessitates the use of lightweight block ciphers. Nevertheless, providing the required security properties does not guarantee their reliability and hardware assurance when the architectures are prone to natural and malicious faults. In this letter, error detection schemes for lightweight block ciphers are proposed with the case study of XTEA (eXtended TEA). Lightweight block ciphers such as XTEA, PRESENT, SIMON, and the like might be better suited for low-resource deeply-embedded systems compared to the Advanced Encryption Standard. Three different error detection approaches... 

The extended Euclidean algorithm (EEA) is an important scheme for performing the division operation in finite fields. Many sensitive and security-constrained applications such as those using the elliptic curve cryptography for establishing key agreement schemes, augmented encryption approaches, and digital signature algorithms utilize this operation in their structures. Although much study is performed to realize the EEA in hardware efficiently, research on its reliable implementations needs to be done to achieve fault-immune reliable structures. In this regard, this paper presents a new concurrent error detection (CED) scheme to provide reliability for the aforementioned sensitive and... 

Augmenting the security of cryptographic algorithms by protecting them against side-channel active attacks (and natural faults) is essential in cryptographic engineering. BLAKE algorithm is an efficient hash function which has been developed based on Bernstein's ChaCha stream cipher. Because of the fact that Google has chosen ChaCha along with Bernstein's Poly1305 message authentication code as a replacement for RC4 in TLS for Internet security, BLAKE's implementation is of paramount importance. In this paper, we present high-performance fault detection schemes for BLAKE. Specifically, for the round function, two fault diagnosis approaches are developed and analyzed in terms of error... 

In cryptographic engineering, extensive attention has been devoted to ameliorating the performance and security of the algorithms within. Nonetheless, in the state-of-the-art, the approaches for increasing the reliability of the efficient hash functions ECHO and Fugue have not been presented to date.We propose efficient fault detection schemes by presenting closed formulations for the predicted signatures of different transformations in these algorithms. These signatures are derived to achieve low overhead for the specific transformations and can be tailored to include byte/word-wide predicted signatures. Through simulations, we show that the proposed fault detection schemes are... 

The main concern of steganography (image hiding) methods is to embed a secret image into a host image in such a way that the host should remain as similar as possible to its original version. In addition the host image should remain robust with respect to usual attacks. In this paper we present a method that tries to cover all above mentioned concerns. The secret and host images are divided into blocks of size 4 × 4. Each block in secret image is taken as a texture pattern for which the most similar block is found among the blocks of the host image. The embedding procedure is carried on by replacing these small blocks of the secret image with blocks in host image in such a way that least... 

The phase formation and the variation of the normal phonon frequencies of high temperature superconductors YBa2Cu3O7-δ and GdBa2Cu3O7-δ upon doping Tb and Ce for Y and Gd, respectively, have been investigated using XRD and Raman spectroscopy measurements. It is found that the increase of doping content causes the formation of impurity phases that can be detected in the XRD and Raman spectra, and results in the suppression of superconductivity. Moreover, analysis of the Raman peaks reveals that substitutions of Tb and Ce for Y and Gd in the parent structure are restricted to low concentrations in favor of impurity island formation. © 2008  

The spin structure in a magnetic dot is studied as a function of the exchange coupling strength and dot size within the semiclassical approximation on a discrete lattice. As the exchange coupling is decreased or the size is increased, the ground state undergoes a phase change from a homogeneous single-domain ferromagnet (HSDF) to a spin vortex. The line separating these two phases has been calculated numerically for small system sizes. The dipolar interaction has been fully included in our calculations. Magnon frequencies in such a dot have also been calculated in both phases by the linearized equation of motion method. These results have also been reproduced from the Fourier transform of... 

In this paper, two different hybrid intelligent systems are applied to develop practical soft identifiers for modeling the tool-tissue force as well as the resulted maximum local stress in laparoscopic surgery. To conduct the system identification process, a 2D model of an in vivo porcine liver was built for different probing tasks. Based on the simulation, three different geometric features, i.e. maximum deformation angle, maximum deformation depth and width of displacement constraint of the reconstructed shape of the deformed body are extracted. Thereafter, two different fuzzy inference paradigms are proposed for the identification task. The first identifier is an adaptive co-evolutionary... 

The acidity and stability constants of M (MNPPAP) (MNPPAP: 2((4-methyl-5-nitro-6-(pyrrolidine-l-yl)pyrimidine-2-yl)amino)propionic acid) M: Cu2+, Cu (Bpy)2+ (Bpy: 2,2'-Bipyridine), or Cu(Phen) (Phen: 1,10-Phenanthroline) complexes were determined by potentiometric pH titration. It is shown that the stability of the binary Cu (MNPPAP) complex is determined by the basicity of the carboxylate group on one side and amine group on the other side. It is demonstrated that the equilibrium, Cu(Har)2+ (H ar: Heteroaromatic ligand such as Bpy or Phen) + Cu(MNPPAP) ^ Cu(Har)(MNPPAP) + Cu2+, is displacement due to the well known experience that mixed ligand complexes formed by a divalent 3d ion, a... 

A numerical analysis for determination of the stagnant and dispersion thermal conductivities in the Resin Transfer Molding (RTM) process is presented. A solution was obtained for the momentum and energy equations, which are used in this study and which represent the Brinkman- Forchheimer-extended Darcy model, and one-temperature energy equation. Subject to the appropriate boundary conditions, the governing equations are solved by the finite volume method on a collocated grid. In order to satisfy the pressure-velocity coupling in the solution, the SIMPLE algorithm was used and for determining the mass flux flowing past the cell faces, the Rhie-Chow interpolation was applied. Both constant and... 

A new facile strategy for preparation of mesoporous anatase-TiO2 films by a combination of sol–gel and evaporation-induced self-assembly (EISA) processes aided by tri-block Pluronic F127 is reported. Two major parameters, sol preparation and EISA processing parameters, are identified for preparation of mesoporous crack-free films with desired thickness. The mesoporous crack-free films with thickness of 650 nm can be obtained with low water: precursor molar ratio (e.g., 2.5:1) under aging in 10 % relative humidity for 72 h at the low temperature of 5 °C. Although template: precursor molar ratio and annealing temperature show little influence on preparation of crack-free films the optimum... 

The interaction between two spherical colloidal particles with degenerate planar anchoring in a nematic media is studied by numerically minimizing the bulk Landau-de Gennes and surface energy using a finite element method. We find that the energy achieves its global minimum when the particles are in close contact and forming an angle = 28°± 2 with respect to the bulk nematic director, in agreement with the experiments. Although the quadrupolar structure of the director field is preserved in the majority of configurations, we show that for smaller orientation angles and at smaller inter-particle separations, the axial symmetry of the topological defect-pairs is continuously broken, resulting... 

The secure hash algorithm (SHA)-3 has been selected in 2012 and will be used to provide security to any application which requires hashing, pseudo-random number generation, and integrity checking. This algorithm has been selected based on various benchmarks such as security, performance, and complexity. In this paper, in order to provide reliable architectures for this algorithm, an efficient concurrent error detection scheme for the selected SHA-3 algorithm, i.e., Keccak, is proposed. To the best of our knowledge, effective countermeasures for potential reliability issues in the hardware implementations of this algorithm have not been presented to date. In proposing the error detection... 

Today the need for fault diagnosis in polymer electrolyte membrane fuel cells (PEMFCs) is felt more than ever to increase the useful life and durability of the cell. The present study proposes an indirect in-situ experimental-based algorithm for diagnosing the moisture content issues in a three-cell stack. Three adaptive neuro-fuzzy inference systems (ANFIS) approximate the system outputs (cells voltages, cathodic and anodic pressure drop) in normal conditions. The values of Pearson's correlation coefficients (0.998, 0.983, and 0.995 for outputs, respectively) show the high quality of the modeling. In unknown operating conditions, the residuals of experimental and ANFIS values are compared... 

Long-term distribution network planning (DNP) is considered as one of the most challenging issues for distribution network operators (DNOs). By increasing EVs in cities, it has appeared some new players such as electric vehicles (EVs) owners and electric vehicle parking lots (EVPLs) owners for DNP. In this article, we conduct a new study on the coupled dynamic expansion problem of EVPLs placement and distribution networks. To reach this goal, at first, EVs driving and charging/discharging behavior as some influential factors is modeled using an efficient probabilistic algorithm. An analytical model is then introduced to estimate the number of EVs in EVPLs at different times. To find out the... 

Let G be a graph with no isolated vertex. A total dominating set of G is a set S of vertices of G such that every vertex is adjacent to at least one vertex in S. The total domatic number of a graph is the maximum number of total dominating sets which partition the vertex set of G. In this paper we provide a criterion under which a cubic graph has total domatic number at least two  

Falling film heat and mass transfer analysis of a horizontal tube bundle in a generator of absorption chillers have been studied. The film Reynolds number is limited to the laminar flow and the effect of ripple on the free surface has been ignored. Thermal boundary conditions are considered to be constant wall temperature and desorption is considered to be free surface evaporation. Analysis is based on a single column of horizontal tubes, arranged in a vertically spaced configuration. A comprehensive numerical code has been developed to solved the governing equations. The functional relationship of average heat transfer coefficient of tube bundle has been analytically correlated to the first... 

The objective of this paper is to provide optimization of falling film LiBr solution on a horizontal single tube based on minimization of entropy generation. Flow regime is considered to be laminar. The effect of boiling has been ignored and wall temperature is constant. Velocity, temperature and concentration distributions are numerically determined and dimensionless correlations are obtained to predict the average heat transfer coefficient and average evaporation factor on the horizontal tube. Thermodynamic imperfection due to passing lithium bromide solution is attributed to nonisothermal heat transfer; fluid flow friction and mass transfer irreversibility. Scale analysis shows that the... 

Proton exchange membrane fuel cell (PEMFC) is a rich source of renewable energy. A non-destructive prediction method is needed to determine the content of water in the PEMFC. In the gas channel of a transparent PEMFC, water is detected with image processing. This method has a high computational cost and is sensitive to the initial position of the camera and ambient lighting. In this paper, the deep neural network (DNN) has been trained to learn the transparent PEMFC's labeled images as a way to determine the content of water, limit human interference and employed in a real-time process. This DNN model is a virtual sensor for measuring the water coverage ratio. To produce the label of images,... 

Recently, it is shown that, if D is a finite-dimensional division ring, then GLn(D) is not finitely generated. Our object here is to provide a general framework for the groups of units of left Artinian rings. We prove that, if R is an infinite F-algebra of finite dimension over F, then U(R) is not finitely generated. We show that any infinite subnormal subgroup of GL n (D) has no finite maximal subgroup. Also, we prove that for any infinite left Artinian ring R, U(R) has no finite maximal subgroup, which is a result analogous to that for rings. © Inst. Math. CAS 2002