Narrow Results

When it comes to filtering and compressing data before sending it to a cloud server, fog computing is a rummage sale. Fog computing enables an alternate method to reduce the complexity of medical image processing and steadily improve its dependability. Medical images are produced by imaging processing modalities using X-rays, computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, and ultrasound (US). These medical images are large and have a huge amount of storage. This problem is being solved by making use of compression. In this area, lots of work is done. However, before adding more techniques to Fog, getting a high compression ratio (CR) in a shorter time is required, therefore consuming less network traffic. Le Gall5/3 integer wavelet transform (IWT) and a set partitioning in hierarchical trees (SPIHT) encoder were used in this study’s implementation of an image compression technique. MRI is used in the experiments. The suggested technique uses a modified CR and less compression time (CT) to compress the medical image. The proposed approach results in an average CR of 84.8895%. A 40.92% peak signal-to-noise ratio (PSNR) PNSR value is present. Using the Huffman coding, the proposed approach reduces the CT by 36.7434 s compared to the IWT. Regarding CR, the suggested technique outperforms IWTs with Huffman coding by 12%. The current approach has a 72.36% CR. The suggested work’s shortcoming is that the high CR caused a decline in the quality of the medical images. PSNR values can be raised, and more effort can be made to compress colored medical images and 3-dimensional medical images.

Let $f(x)=x^8+a{x}^4+b$ be an irreducible polynomial with rational coefficients and Galois group $\mathrm{\text{Gal}}(f)$. We extend previous results to give an elementary classification of $\mathrm{\text{Gal}}(f)$, identified as a transitive subgroup of $S_8$ up to conjugacy. We show $\mathrm{\text{Gal}}(f)$ is one of 12 possibilities and can be determined by considering the squareness of at most 11 rational numbers; each number is an expression involving $a$ and $b$. We give several applications of our results.

The classical cellular automata model has been modified by introducing "shadow" states or perturbations to represent the application of external signals to a configuration of discrete individual units. Simple update rules are studied to determine which of them are best suited to produce the emergent computation which can simulate signal transmission within a system. The study is made with a view to understanding electrical signalling in plant cells which are known to determine plant responses to the environment.

The possible existence of quantum crystals phase of polariton condensate in two-dimensional microcavity polariton was studied by using mean-field method for bosons at zero temperature. In this study, we observe the supersolid crystallized (hexagonal, square) and a quantized winding number of the phase in a regime of strong- field interaction in rotating exciton–polariton condensates. First, the ground state of the condensate was found; and the solution was further extended for dynamics state to reach the equilibrium steady-state as well as their density profile and energy diagrams. The supersolid crystal is the result of the considerable deviation induced by the interaction of polaritons of both ground and dynamic states of a dressed dipolar Bose–Einstein condensate. Here, the researchers demonstrated the formation of a hexagonal lattice in the nonlinear regime at high polariton-density where polariton–polariton interactions dominate the behavior of the system. It was identified that stability regimes for ground state increases as the polariton–polariton interaction strength increases. The phase diagram for the stable vortex state will be useful for conducting experimental and theoretical studies on rotating dipolar quantum gases and many other exotic systems.

In this paper, a new robot path planning algorithm based on Quantum-inspired Evolutionary Algorithm (QEA) is proposed. QEA is an advanced evolutionary computing scheme with the quantum computing features such as qubits and superposition. It is suitable for solving large scale optimization problems. The proposed QEA algorithm works in the discretized environment, and approximates the optimal robot planing path in a highly computationally efficient fashion. The simulation results indicate that the proposed QEA algorithm is suitable for both complex static and dynamic environment and considerably outperforms the conventional genetic algorithm (GA) for solving the robot path planning problem. Our algorithm runs in only about 2s, which demonstrates that it can well tackle the optimization problem in robot path planning.

We review a neural network model based on chaotic dynamics [Babloyantz & Lourenço, 1994, 1996] and provide a detailed discussion of its biological and computational relevance. Chaos can be viewed as a "reservoir" containing an infinite number of unstable periodic orbits. In our approach, the periodic orbits are used as coding devices. By considering a large enough number of them, one can in principle expand the information processing capacity of small or moderate-size networks. The system is most of the time in an undetermined state characterized by a chaotic attractor. Depending on the type of an external stimulus, the dynamics is stabilized into one of the available periodic orbits, and the system is then ready to process information. This corresponds to the system being driven into an "attentive" state. We show that, apart from static pattern processing, the model is capable of dealing with moving stimuli. We especially consider in this paper the case of transient visual stimuli, which has a clear biological relevance. The advantages of chaos over more regular regimes are discussed.

It is experimental evidence that biological neocortical neurons are arranged in a columnar clustered architecture and coupled according to a bi-power law connection probability function. We propose a computational framework that relies on recurrent connectivity and work out associated computational properties. Taking the columns as the basic computational elements, we investigate a bi-power connection probability function paradigm, in order to scan a wide range of network types, for which we measure the speed of information propagation and synchronizability. Whereas the speed of information propagation increases linearly in the neighbor order n for n-nearest neighbor coupled networks, for close-to-biology bi-power models of the cortex it quickly saturates at high values, expressing the superiority of this network type. Our results reveal that these networks optimize information propagation and synchronizability at a minimal total connection length.

A thin-layer Belousov–Zhabotinsky (BZ) medium is a powerful computing device capable for implementing logical circuits, memory, image processors, robot controllers, and neuromorphic architectures. We design the reversible logical gates — Fredkin gate and Toffoli gate — in a BZ medium network of excitable channels with subexcitable junctions. Local control of the BZ medium excitability is an important feature of the gates’ design. An excitable thin-layer BZ medium responds to a localized perturbation with omnidirectional target or spiral excitation waves. A subexcitable BZ medium responds to an asymmetric perturbation by producing traveling localized excitation wave-fragments similar to dissipative solitons. We employ interactions between excitation wave-fragments to perform the computation. We interpret the wave-fragments as values of Boolean variables. The presence of a wave-fragment at a given site of a circuit represents the logical truth, absence of the wave-fragment — logically false. Fredkin gate consists of ten excitable channels intersecting at 11 junctions, eight of which are subexcitable. Toffoli gate consists of six excitable channels intersecting at six junctions, four of which are subexcitable. The designs of the gates are verified using numerical integration of two-variable Oregonator equations.

This paper presents results on the dynamics of asynchronous irregular cellular automata (as representations of natural information-processing systems). It is an approach to explaining global dynamics from local dynamics without the use of unrealistic intermediate structure (i.e., without synchronization or regular communication). The unrealistic intermediate structure is replaced by the the realistic assumption that local behavior is entropy reducing (an idea of E. Schrödinger).

It has been shown that, for systems composed of cells programmed as cyclic finite-state automata, the observed global oscillation can be explained in terms of the structure of attractors in the global state space. The degree of local connectivity (i.e., of communication between cells) is shown here to determine the size of global attractors, and in turn the sharpness of global behavior. However, the primary result here is the extension of these results to systems whose cells are programmed as arbitrary strongly connected automata. Finally, these phenomena are demonstrated by the simulations.

It has been known since 1987 that many features of supernovae cannot be described by the spherically-symmetric picture assumed in one-dimensional explosion models. However, the study of the propagation of a supernova shock through a star in more than one spatial dimension is still in its infancy. Understanding this propagation, and the mixing associated with it, is critical for determining accurate supernova yields and correctly interpreting observations based on those yields — from gamma-rays and overall light curves produced in supernova explosions to the abundances of isotopes studied in stars. Here we review the current state-of-the-art in this field. By necessity, this problem is computational and therefore provides an ideal setting to discuss how verification and validation techniques can play an important role in taking full advantage of the results from numerical simulations. We discuss this problem using the full arsenal of verification and validation techniques currently available.

Information I in holographic imaging of massive particles by star-like screens is shown to represent the probability of detection based on their propagator. Results are derived for screens in the shape of a plane, cube and sphere from unitarity in the exponentially small transition probability for a detection outside. We derive I = 2πΔφ in log 2 bits for the imaging of a particle by a spherical screen at a relative de Broglie phase Δφ. Encoding mass, charge, angular momentum or radiation requires at minimum four bits. Minimal screens at maximal information density hereby recover Reissner–Nordström and extremal Kerr black holes. Applied to the visible Universe, the Hubble flow of galaxies through the cosmological event horizon leaves 10¹²¹ computations in the future.

This paper uses the chaotic fuzzy encryption (CFE) technique and a greedy chemical reaction optimization algorithm based on mobile cloud computing to protect data from any assault. Mobile users who use protected mobile cloud computing (Mobi-Cloud) must trust the cloud service provider to keep the data sent from their mobile devices safe when mobile users express strong reservations about storing personal information in the public cloud. The Greedy Chemical Reaction Optimization (G-CRO) algorithm reduces critical limitations by determining the offloading end with motion at run time, i.e. the task’s operating time, CPU usage, memory utilization, and energy usage. The experimental results show that the proposed method performs better in terms of file uploading time, file downloading time, memory usage in file uploading, memory usage in file downloading, encryption time, decryption time, memory usage on file encryption, memory usage on file decryption, security levels, and key generation time. Compared to the Proxy Re-Encryption (PRE) algorithm, the suggested method consumes less time for key creation (26.04).

A formula is presented for computing the equilibrium payoffs in a generic finite two-person game when the support of the equilibrium is known.

This contribution addresses the fundamental critique in Dinar et al. [1992, Theory and Decision32] on the use of game theory in river basin management: People are reluctant to monetary transfers unrelated to water prices and game theoretic solutions impose a computational burden. For the bilateral alternating-offers model, a single optimization program significantly reduces the computational burden. Furthermore, water prices and property rights result from exploiting the Second Welfare Theorem. Both issues are discussed and applied to a bilateral version of the theoretical river basin model in Ambec and Sprumont [2002, Journal of Economic Theory107]. Directions for future research are provided.

In this paper we study and compute E-points in an explicit way for a special general kind of 3k + 1 and 3k + 2 players.

Let $f(x)=x^8+a{x}^4+b$ be an irreducible polynomial with rational coefficients, $K/Q$ the number field defined by $f$, and $G$ the Galois group of $f$. Let $g(x)=x^4+a{x}^2+b$, and let $G_4$ be the Galois group of $g$. We investigate the extent to which knowledge of the conjugacy class of $G_4$ in $S_4$ determines the conjugacy class of $G$ in $S_8$. We show that, in general, knowledge of $G_4$ does not automatically determine $G$, except when $G_4$ is isomorphic to $C_4$ (the cyclic group of order 4). In this case, we show $G$ is isomorphic to a non-split extension of $D_4$ (the dihedral group of order 8) by $C_4$. We also show that $G$ is completely determined when $G_4$ is isomorphic to $D_4$ and $4b-a^2$ is a perfect square. In this case, $G\simeq C_4\wr C_2\simeq (C_4\times C_4)⋊C_2$.

We present a brief discussion on the impact of information technology on problems from finance and economics. Then, an overview is given upon the papers that are included in the special issue.

Theoretical calculations have been carried out to investigate the effect of the 4(R)-substituents (OH, F, NH₂, and ) in proline on the stability of the collagen triple helix. A series of substituted proline models were studied first with density functional (B3LYP/6-31+G*) calculations. The solvent effect was studied using the SCIPCM method. While the F, OH and NH₂ groups increase the stability of the trans-up conformation with respect to the trans-down conformation, appears to favor the trans-down conformation in an aqueous solution. Second, the triple helices of the tripeptide models, Ac–Pro–Pro(X)–Gly–H with the two proline residues in the down/down and down/up puckering conformations, were optimized with a repeating unit approach using the HF/6-31G* method. For the Ac–Pro–Pro–Gly–H model peptide, the calculated binding energies of the two triple helices with the different puckering modes are similar. All four substituents, F, OH, NH₂, and , considerably increased the binding energy of the down/up helix, but only stabilizes the down/down triple helix. Our calculations indicate that the inter-chain electrostatic interactions involving the 4(R)-substituents play an important role in stabilizing triple helical collagen models and allow the rationalization of all available experimental observations. Further model studies indicate that the substituent effects by the F, OH and NH₂ substituents are local while the effect of is long-range in nature.

A detailed computational study is performed on the radical-molecule reactions between HCO/HOC and ethylene (C₂H₄) at the Gaussian-3//B3LYP/6-31G(d) level. For the HCO + C₂H₄ reaction, the most favorable pathway is the direct C-addition forming the intermediate H₂CCH₂CHO, followed by a 1,2-H-shift leading to H₃CCHCHO. Subsequently, there are two highly competitive dissociation pathways for H₃CCHCHO: one is the formation of the direct H-extrusion product H₂CCHCHO + H, and the other is the formation of C₂H₅ + CO via the intermediate H₃CCH₂CO. The overall reaction barrier is 14.1 and 14.6 kcal/mol respectively, at the G3B3 level. The quasi-direct H-donation process to produce C₂H₅ + CO with the barrier 16.5 kcal/mol is less competitive. Thus, only at higher temperatures, the HCO + C₂H₄ reaction could play a role. In contrast, the HOC + C₂H₄ reaction just need to overcome a small barrier 2.0 kcal/mol to generate C₂H₅ + CO via the quasi-direct H-donation mechanism. This is suggestive of the potential importance of the HOC + C₂H₄ reaction in combustion processes. However, the direct C-addition channel is much less competitive. The present kinetic data and orbital analysis show that the HCO radical has much higher reactivity than HOC, although the latter is more energetic. Till now, no kinetic study on the HOC radical has been reported, the present study can provide useful information on understanding the reactivity and depletion mechanism of the energetic HOC radical.

A molecular dynamics simulation of the folding of a short helical toxin peptide was carried out. The simulation gave a folding time of ~10 ns, which is longer than typical time of ~1 ns for the formation of 1–2 helical turns. The simulation demonstrates that a helical peptide with disulfide bonds, which may encounter extra steric hindrance compared with the peptide without disulfide bonds, can fold in nanosecond timescale. An analysis shows that this folding time should correspond to the folding time in weak denaturation condition in experiment. Interactions and factors affecting folding pathways are analyzed and discussed.