The total graph and regular graph of a commutative ring

Let R be a commutative ring. The total graph of R, denoted by T(Γ(R)) is a graph with all elements of R as vertices, and two distinct vertices x,y∈R, are adjacent if and only if x+y∈Z(R), where Z(R) denotes the set of zero-divisors of R. Let regular graph of R, Reg(Γ(R)), be the induced subgraph of T(Γ(R)) on the regular elements of R. Let R be a commutative Noetherian ring and Z(R) is not an ideal. In this paper we show that if T(Γ(R)) is a connected graph, then . Also, we prove that if R is a finite ring, then T(Γ(R)) is a Hamiltonian graph. Finally, we show that if S is a commutative Noetherian ring and Reg(S) is finite, then S is finite.     

Enhanced adaptive fuzzy sliding mode control for uncertain nonlinear systems

In this article, a novel Adaptive Fuzzy Sliding Mode Control (AFSMC) methodology is proposed based on the integration of Sliding Mode Control (SMC) and Adaptive Fuzzy Control (AFC). Making use of the SMC design framework, we propose two fuzzy systems to be used as reaching and equivalent parts of the SMC. In this way, we make use of the fuzzy logic to handle uncertainty/disturbance in the design of the equivalent part and provide a chattering free control for the design of the reaching part. To construct the equivalent control law, an adaptive fuzzy inference engine is used to approximate the unknown parts of the system. To get rid of the chattering, a fuzzy logic model is assigned for reaching control law, which acting like the saturation function technique. The main advantage of our proposed methodology is that the structure of the system is unknown and no knowledge of the bounds of parameters, uncertainties and external disturbance are required in advance. Using Lyapunov stability theory and Barbalat’s lemma, the closed-loop system is proved to be stable and convergence properties of the system is assured. Simulation examples are presented to verify the effectiveness of the method. Results are compared with some other methods proposed in the past research.     

Synthese des substances de groupe sanguin—IX: Une synthese du 2-o-(α-l-fucopyranosyl)-3-o-(α-d-galactopyranosyl)-d-galactose,le determinant antigenique du groupe sanguin b

The trisaccharide 2-O-(α-L-fucopyranosyl)-3-O-(α-D-galactopyranosyl)-D-galactose has been synthesised stereospecifically using the imidate procedure. Allyl 3-O-benzoyl-4,6-O-benzylidene-β-D-galactopyranoside was first α-L-fucosylated by 1-O-(N-methyl)-acetimidyl-2,3,4-tri-O-benzyl-β-L-fucopyranose then, after O-debenzoylation, α-D-galactosylated by 1-O-(N-methyl)-acetimidyl 2,3,4,6-tetra-O-benzyl-β-D-galactopyranose. The resulting tri-saccharide has also been obtained from allyl 2-O-benzoyl-4,6-O-benzylidene-β-D-galactopyranoside after α-D-galactosylation, O-debenzoylation and α-L-fucosylation. The glycosylations were performed at room temperature in nitromethane in the presence of p-toluenesulfonic acid. Deallylation followed by catalytic hydrogenolysis gave the B blood-group antigenic determinant. The allyl group was also selectively transformed into hydroxyethyl group.     

Compact MOS Implementation of a Reaction-Diffusion CNN

A biologically inspired single layer cellular neural network (CNN) with trigger wave formation capability is presented. A novel compact MOS cell circuit is proposed which exhibits a third order I-V characteristic with negative differential resistance (NDR). Certain D.C. characteristics of both the proposed cell and the network are described and corresponding theoretical estimations are presented. It is shown that the CNN formed by resistive coupling of these cells has very low complexity and realizes a reaction-diffusion system. The dynamical network behavior is demonstrated by transient simulations of a 2D cell array at the circuit level.Koray Karahalilolu received the B.Sc., M.Sc., and Ph.D. degrees in electrical engineering from Boaziçi University, Istanbul, Turkey, in 1993, 1996, and 2002, respectively.Currently he is a Research Assistant Professor with the Department of Electrical Engineering, University of Nebraska, Lincoln. He also worked as a teaching assistant with the Department of Electrical and Electronics Engineering at Boaziçi University.His research interests include VLSI neural networks, device modeling and simulation, analog circuits and systems, and nanodevice system applications.Sina Balkr received the B.S. degree in electrical engineering from Boaziçi University, Istanbul, Turkey, in 1987, and the M.S. and Ph.D. degrees in electrical engineering from Northwestern University, Evanston, IL, in 1989 and 1992, respectively.Between August 1992 and August 1998, he was with the Department of Electrical and Electronics Engineering, Boaziçi University, as an Assistant and Associate Professor. Currently, he is with the Department of Electrical Engineering, University of Nebraska-Lincoln. His research interests include CAD of VLSI systems, analog VLSI design automation, and focal-plane computation arrays for image processing.     

Kernel regression for image processing and reconstruction.

In this paper, we make contact with the field of nonparametric statistics and present a development and generalization of tools and results for use in image processing and reconstruction. In particular, we adapt and expand kernel regression ideas for use in image denoising, upscaling, interpolation, fusion, and more. Furthermore, we establish key relationships with some popular existing methods and show how several of these algorithms, including the recently popularized bilateral filter, are special cases of the proposed framework. The resulting algorithms and analyses are amply illustrated with practical examples.     

Comparison of Peptide Ion Conformers Arising from Non-Helical and Helical Peptides Using Ion Mobility Spectrometry and Gas-Phase Hydrogen/Deuterium Exchange

The dominant gas-phase conformer of [M+3H]³⁺ ions of the model peptide acetyl-PSSSSKSSSSKSSSSKSSSSK has been examined with ion mobility spectrometry (IMS), gas-phase hydrogen deuterium exchange (HDX), and mass spectrometry (MS) techniques. The [M+3H]³⁺ peptide ions are observed predominantly as a relatively compact conformer type. Upon subjecting these ions to electron transfer dissociation (ETD), the level of protection for each amino acid residue in the peptide sequence is assessed. The overall per-residue deuterium uptake is observed to be relatively more efficient for the neutral residues than for the model peptide acetyl-PAAAAKAAAAKAAAAKAAAAK. In comparison, the N-terminal and C-terminal regions of the serine peptide show greater relative protection compared with interior residues. Molecular dynamics (MD) simulations have been used to generate candidate structures for collision cross section and HDX reactivity matching. Hydrogen accessibility scoring (HAS) for select structural candidates from MD simulations has been used to suggest conformer types that could contribute to the observed HDX patterns. The results are discussed with respect to recent studies employing extensive MD simulations of gas-phase structure establishment of a peptide system.

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A total synthesis of natural cerulenin from D-glucose

$\text{D}$-glucose has served as a chiral synthon in a total synthesis of the fungal metabolite cerulenin.     

Hydrogel−Solid Hybrid Materials for Biomedical Applications Enabled by Surface‐Embedded Radicals

Combinations of hydrogels and solids provide high level functionality for devices such as tissue engineering scaffolds and soft machines. However, the weak bonding between hydrogels and solids hampers functionality. Here, a versatile strategy to develop mechanically robust solid?hydrogel hybrid materials using surface embedded radicals generated through plasma immersion ion implantation (PIII) of polymeric surfaces is reported. Evidence is provided that the reactive radicals play a dual role: inducing surface‐initiated, spontaneous polymerization of hydrogels; and binding the hydrogels to the surfaces. Acrylamide and silk hydrogels are formed and covalently attached through spontaneous reactions with the radicals on PIII activated polymer surfaces without cross‐linking agents or initiators. The hydrogel amount increases with incubation time, monomer concentration, and temperature. Stability tests indicate that 95% of the hydrogel is retained even after 4 months in PBS solution. T‐peel tests show that failure occurs at the tape?hydrogel interface and the hydrogel‐PIII‐treated PTFE interfacial adhesion strength is over 300 N m^?1. Cell assays show no adhesion to the as‐synthesized hydrogels; however, hydrogels synthesized with fibronectin enable cell adhesion and spreading. These results show that polymers functionalized with surface‐embedded radicals provide excellent solid platforms for the generation of robust solid?hydrogel hybrid structures for biomedical applications.