Reliability-aware core partitioning in chip multiprocessors

Executing multiple applications concurrently is an important way of utilizing the computational power provided by emerging chip multiprocessor (CMP) architectures. However, this multiprogramming brings a resource management and partitioning problem, for which one can find numerous examples in the literature. Most of the resource partitioning schemes proposed to date focus on performance or energy centric strategies. In contrast, this paper explores reliability-aware core partitioning strategies targeting CMPs. One of our schemes considers both performance and reliability objectives by maximizing a novel combined metric called the vulnerability-delay product (VDP). The vulnerability component in this metric is represented with Thread Vulnerability Factor (TVF), a recently proposed metric for quantifying thread vulnerability for multicores. Execution time of the given application represents the delay component of the VDP metric. As part of our experimental analysis, proposed core partitioning schemes are compared with respect to normalized weighted speedup, normalized weighted reliability loss and normalized weighted vulnerability delay product gain metrics for various workloads of benchmark applications.     

Synthesis of imine bond containing insoluble polymeric ligand and its transition metal complexes,structural characterization and catalytic activity on esterification reaction

In this study, synthesis of insoluble polymeric ligand (L) and its transition metal complexes [Cu(L)Cl₂]·2H₂O (1), [Co(L)Cl₂(H₂O)₂] (2) and [Ni(L)Cl₂(H₂O)₂] (3), having the azomethine groups, were synthesized by the condensation reactions of the diamines and dialdehydes. The structural properties were characterized by the analytical and spectroscopic methods using by elemental analysis, Fourier Transform Infrared, Thermo Gravimetric Analysis, Powder X-ray Diffraction, magnetic susceptibility and Inductively Coupled Plasma. The solubilities of the synthesized polymeric materials were also investigated and found as insoluble some organic and inorganic solvents. Additionally, their catalytic performance was carried out for the esterification reaction of acetic acid and butyl acetate. The highest conversion rate is 75.75% by using catalyst 1. The esterification of butanol gave butyl acetate with 100% selectivity.     

Reducing Soft Errors through Operand Width Aware Policies

Soft errors are an important challenge in contemporary microprocessors. Particle hits on the components of a processor are expected to create an increasing number of transient errors with each new microprocessor generation. In this paper, we propose simple mechanisms that effectively reduce the vulnerability to soft errors in a processor. Our designs are generally motivated by the fact that many of the produced and consumed values in the processors are narrow and their upper order bits are meaningless. Soft errors caused by any particle strike to these higher order bits can be avoided by simply identifying these narrow values. Alternatively, soft errors can be detected or corrected on the narrow values by replicating the vulnerable portion of the value inside the storage space provided for the upper order bits of these operands. As a faster but less fault tolerant alternative to ECC and parity, we offer a variety of schemes that make use of narrow values and analyze their efficiency in reducing soft error vulnerability of different data-holding components of a processor. On average, techniques that make use of the narrowness of the values can provide 49 percent error detection, 45 percent error correction, or 27 percent error avoidance coverage for single bit upsets in the first level data cache across all Spec2K. In other structures such as the immediate field of the issue queue, an average error detection rate of 64 percent is achieved.     

Application of intelligent sliding mode control with moving sliding surface for overhead cranes

In this paper, neural-based fuzzy logic sliding mode control with moving sliding surface has been designed for supervision of an overhead crane. A mathematical model has been established of the crane, and equations of motion have been obtained. First, the suitable sliding surface coefficient has been determined for the fixed sliding surface in the design of sliding mode control. The sliding surface has been moved by using neural-based fuzzy logic algorithm to eliminate disadvantage of the regular sliding mode control. By application of this control algorithm, the control performance incredibly increased. In the application, during the carriage of the load to a target which was 1 m away by a crane with 3 kg of load and 100 cm of rope length, the parameters of effected controllers were updated and their training was realized. In order to display the insensitiveness of the controller to parametric uncertainty, the value of the load was taken as 8 kg and the length of the rope was taken as 3 m and controls for a different target were realized. MATLAB program was used for numerical solutions, and results were examined graphically. Obtained results displayed the success of the algorithm of neural-based fuzzy logic sliding mode control.     

Vernier Threshold in Patients With Schizophrenia and in Their Unaffected Siblings.

The aim of this study was to investigate magnocellular (M) and parvocellular (P) visual functions in nonmedicated patients with schizophrenia and in their unaffected siblings. Possible abnormalities in cortical integration of retinal receptive fields also were addressed. Twenty-two nonmedicated patients with schizophrenia, their unaffected siblings, and 20 age- and IQ-matched healthy control subjects received 4 vernier acuity tasks (blue-on-yellow, frequency-doubling, achromatic low and high contrast conditions) in which they were asked to detect the spatial alignment of dots and gratings. Results revealed that the patients with schizophrenia and their unaffected siblings showed selective dysfunctions in the frequency-doubling and achromatic low contrast conditions, which were devoted to investigate M pathways. In the isoluminant blue-on-yellow and high contrast achromatic conditions, there were no significant differences between the experimental groups. These results suggest that the deficit of M pathway is an endophenotype of schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Poly(acrylonitrile-co-itaconic acid)–poly(3,4-ethylenedioxythiophene) and poly(3-methoxythiophene) nanoparticles and nanofibres

This work aimed to produce poly(acrylonitrile-co-itaconic acid) (P(AN-co-IA)) nanocomposites with poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3-methoxythiophene) (PMOT). An anionic surfactant sodium dodecyl benzene sulphonate was used in emulsion polymerization for nanocomposite production. Incorporations of PEDOT and PMOT on the nanoparticles were characterized by scanning electron microscopy (SEM), atomic force microscopy, Fourier transform infrared-attenuated total reflectance spectroscopy and ultra-violet spectroscopy. These nanoparticles were blended with PAN and the blends were electrospun to produce P(AN-co-IA)–polythiophene-derivative-based nanofibres, and the obtained nanofibres were characterized by SEM and energy dispersive spectroscopy. In addition, electrochemical impedance studies conducted on nanofibres showed that PEDOT and PMOT in matrix polymer P(AN-co-IA) exhibited capacitive behaviour comparable to that of ITO–PET. Their capacitive behaviour changed with the amount of electroactive polymer.     

Antibacterial polyacrylonitrile nanofibers produced by alkaline hydrolysis and chlorination

Antibacterial polyacrylonitrile (PAN) nanofibers were developed by alkaline hydrolysis and subsequent chlorination. It was shown that the hydrolyzed nanofibers could serve as an N-halamine precursor through chlorination of the amide groups obtained by partial hydrolysis of the nitrile groups. The hydrolysis conditions were optimized, so that sufficient chlorine for effective antibacterial activities could be obtained on the surfaces. The chemical and physical structural changes were well characterized with FTIR, TGA, DSC and SEM. It was found that even though the hydrolyzed nanofibers cyclized with ionic and free radical mechanisms, the chlorinated nanofibers cyclized with only free radical mechanism as evidenced by its higher onset of cyclization temperature. On the other hand, the hydrolysis and chlorination process significantly improved the mechanical properties of the nanofibers. Moreover, the chlorinated nanofibers showed potent antibacterial activities against S. aureus and E. coli with about 6 logs inactivation. The developed antibacterial PAN nanofibers possess great potential for use in various fields, medical industry in particular.     

Determination of the apparent rate constants of the degradation of humic substances by ozonation and modeling of the removal of humic substances from the aqueous solutions with neural network

In this study, the degradation rate constants of humic substances by ozonation under the different empirical conditions such as ozone-air flow rate, ozone generation potential, pH, temperature, powdered activated carbon (PAC) dosage and HCO(3)(-) ions concentration were determined. The ozonation of humic substances in the semi-batch reactor was found to fit pseudo-first-order reaction. The values of apparent rate constant of humic substances degradation increased with the increase of initial ozone-air flow rates, ozone generation potential, pH, temperatures and PAC dosage, but decreased with the increase of HCO(3)(-) concentration of the solution. Using Arrhenius equation, the activation energy (E(a)) of the reaction was found as 1.96 kJ mol(-1). The reaction of ozonation of humic substances under the different temperatures was defined as diffusion control according to E(a). The model based on artificial neural network (ANN) could predict the concentrations of humic substances removal from aqueous solution during ozonation. A relationship between the predicted results of the designed ANN model and experimental data was also conducted. The ANN model yielded determination coefficient of (R(2)=0.995), standard deviation ratio (0.065), mean absolute error (4.057) and root mean square error (5.4967).     

Formation of macroporous poly(acrylamide) hydrogels in DMSO/water mixture: Transition from cryogelation to phase separation copolymerization

Poly(acrylamide) hydrogels were prepared by free-radical crosslinking copolymerization of acrylamide and N,N′-methylenebis(acrylamide) at −18 ^oC in aqueous DMSO solutions of various composition. The hydrogels formed in the solvent mixture with less than 25% DMSO by volume have irregular large pores of about 10¹ μm in diameter, typical for macroporous networks created by the cryogelation technique. Non-porous hydrogels were obtained in solutions containing 25% DMSO, while at larger DMSO contents, the structure of the hydrogel networks consists of aggregates of microspheres, which looks as cauliflowers, typical for a macroporous network formed by reaction-induced phase separation mechanism. Swelling measurements show that fast responsive PAAm hydrogels can be obtained as the DMSO content in the mixed solvent is decreased or increased starting from 25 v/v%. The results were interpreted as the transition from cryogelation to the phase separation copolymerization due to the marked freezing point depression of the solvent mixture as well as due to the action of the mixed solvent as a poor solvating diluent at −18 ^oC. It was also shown that the initial temperature of the cryogelation reactions in water strongly affects the hydrogel properties. Hydrogels formed at an initial temperature T_ini of 0 ^oC were very tough and can be compressed up to about 100% strain without any crack development while those formed at T_ini = 21 ^oC were fragile.