Low power pipelined TCAM employing mismatch dependent power allocation technique

This paper presents design of a Low power 256x72 bit TCAM in 0.13um CMOS technology. In contrast to conventional Match line (ML) sensing scheme in which equal power is consumed irrespective of match or mismatch, the ML scheme employed in this design allocates less power to match decisions involving a large number of mismatched bits. Typically, the probability of mismatch is high so this scheme results in significant CAM power reduction. We propose to use this technique along with pipelining of search operation in which the MLs are broken into several segments. Since most words fail to match in first segment, the search operation for subsequent segments is discontinued, resulting in further reduction in power consumption. The above architecture provides 70% power reduction while performing search in 3ns.

Mismatch repair genes of eukaryotes

Mismatches that arise during replication or genetic recombination or owing to damage to DNA by chemical agents are recognized by mismatch repair systems. The pathway has been characterized in detail in Escherichia coli. Several homologues of the genes encoding the proteins of this pathway have been identified in the yeast Saccharomyces cerevisiae and in human cells. Mutations in the human genes hMSH2, hMLH1, hPMS1 and hPMS2 have been linked to hereditary nonpolyposis colon cancer (HNPCC) and to some sporadic tumours. Mismatch repair also plays an antirecombinogenic role and is implicated in speciation.

Sensitivity analysis based on mode mismatch for an optofluidic lab on a chip biosensor

In this paper we will be presenting the effect of fluidic gap, the effect of change of refractive index of the fluid contained in the gap, and the effect of higher order modes on the efficiency of light coupling and thus on the on the sensitivity of the sensor.

Sensitivity analysis based on Mode Mismatch for an optofluidic lab on a chip biosensor

In this paper we will be presenting the effect of fluidic gap, the effect of change of refractive index of the fluid contained in the gap, and the effect of higher order modes on the efficiency of light coupling and thus on the on the sensitivity of the sensor.

Effects of refractive index mismatch in optical CT imaging of polymer gel dosimeters

Purpose: Proposing an image reconstruction technique, algebraic reconstruction technique-refraction correction (ART-rc). The proposed method takes care of refractive index mismatches present in gel dosimeter scanner at the boundary, and also corrects for the interior ray refraction. Polymer gel dosimeters with high dose regions have higher refractive index and optical density compared to the background medium, these changes in refractive index at high dose results in interior ray bending. Methods: The inclusion of the effects of refraction is an important step in reconstruction of optical density in gel dosimeters. The proposed ray tracing algorithm models the interior multiple refraction at the inhomogeneities. Jacob's ray tracing algorithm has been modified to calculate the pathlengths of the ray that traverses through the higher dose regions. The algorithm computes the length of the ray in each pixel along its path and is used as the weight matrix. Algebraic reconstruction technique and pixel based reconstruction algorithms are used for solving the reconstruction problem. The proposed method is tested with numerical phantoms for various noise levels. The experimental dosimetric results are also presented. Results: The results show that the proposed scheme ART-rc is able to reconstruct optical density inside the dosimeter better than the results obtained using filtered backprojection and conventional algebraic reconstruction approaches. The quantitative improvement using ART-rc is evaluated using gamma-index. The refraction errors due to regions of different refractive indices are discussed. The effects of modeling of interior refraction in the dose region are presented. Conclusions: The errors propagated due to multiple refraction effects have been modeled and the improvements in reconstruction using proposed model is presented. The refractive index of the dosimeter has a mismatch with the surrounding medium (for dry air or water scanning). The algorithm reconstructs the dose profiles by estimating refractive indices of multiple inhomogeneities having different refractive indices and optical densities embedded in the dosimeter. This is achieved by tracking the path of the ray that traverses through the dosimeter. Extensive simulation studies have been carried out and results are found to be matching that of experimental results. (C) 2015 American Association of Physicists in Medicine.

A zero charge-pump mismatch current tracking loop for reference spur reduction in PLLs

The charge-pump (CP) mismatch current is a dominant source of static phase error and reference spur in the nano-meter CMOS PLL implementations due to its worsened channel length modulation effect. This paper presents a charge-pump (CP) mismatch current reduction technique utilizing an adaptive body bias tuning of CP transistors and a zero CP mismatch current tracking PLL architecture for reference spur suppression. A chip prototype of the proposed circuit was implemented in 0.13 mu m CMOS technology. The frequency synthesizer consumes 8.2 mA current from a 13 V supply voltage and achieves a phase noise of -96.01 dBc/Hz @ 1 MHz offset from a 2.4 GHz RF carrier. The charge-pump measurements using the proposed calibration technique exhibited a mismatch current of less than 0.3 mu A (0.55%) over the VCO control voltage range of 0.3-1.0 V. The closed loop measurements show a minimized static phase error of within +/- 70 ps and a similar or equal to 9 dB reduction in reference spur level across the PLL output frequency range 2.4-2.5 GHz. The presented CP calibration technique compensates for the DC current mismatch and the mismatch due to channel length modulation effect and therefore improves the performance of CP-PLLs in nano-meter CMOS implementations. (C) 2015 Elsevier Ltd. All rights reserved.

Thermal mismatch stress in SiC whisker reinforced aluminium composite: new measurement method by X-ray diffraction

A new X-ray diffraction method for characterising thermal mismatch stress (TMS) in SiC_w–Al composite has been developed. The TMS and thermal mismatch strain (TMSN) in SiC whiskers are considered to be axis symmetrical, and can be calculated by measuring the lattice distortion of the whiskers. Not only the average TMS in whiskers and matrix can be obtained, but the TMS components along longitudinal and radial directions in the SiC whiskers can also be deduced. Experimental results indicate that the TMS in SiC whiskers is compressive, and tensile in the aluminium matrix. The TMS and TMSN components along the longitudinal direction in the SiC whiskers are greater than those along the radial direction for a SiC_w–Al composite quenched at 500°C.

Cooperative properties of lipid bilayers : collective director fluctuations and the effects of hydrophobic mismatch in protein/lipid membrane systems

Cooperative director fluctuations in lipid bilayers have been postulated for many years. ^2H-NMR T_1^(-1), T_(1P)^(-1) , and T_2^(-1); measurements have been used identify these motions and to determine the origin of increased slow bilayer motion upon addition of unlike lipids or proteins to a pure lipid bilayer.

The contribution of cooperative director fluctuations to NMR relaxation in lipid bilayers has been expressed mathematically using the approach of Doane et al.^1 and Pace and Chan.^2 The T_2^(-1)’s of pure dimyristoyllecithin (DML) bilayers deuterated at the 2, 9 and 10, and all positions on both lipid hydrocarbon chains have been measured. Several characteristics of these measurements indicate the presence of cooperative director fluctuations. First of all, T_2^(-1) exhibits a linear dependence on S2/CD. Secondly, T_2^(-1) varies across the ^2H-NMR powder pattern as sin^2 (2, β), where , β is the angle between the average bilayer director and the external magnetic field. Furthermore, these fluctuations are restricted near the lecithin head group suggesting that the head group does not participate in these motions but, rather, anchors the hydrocarbon chains in the bilayer.

T_2^(-1)has been measured for selectively deuterated liquid crystalline DML hilayers to which a host of other lipids and proteins have been added. The T_2^(-1) of the DML bilayer is found to increase drastically when chlorophyll a (chl a) and Gramicidin A' (GA') are added to the bilayer. Both these molecules interfere with the lecithin head group spacing in the bilayer. Molecules such as myristic acid, distearoyllecithin (DSL), phytol, and cholesterol, whose hydrocarbon regions are quite different from DML but which have small,neutral polar head groups, leave cooperative fluctuations in the DML bilayer unchanged.

The effect of chl a on cooperative fluctuations in the DML bilayer has been examined in detail using ^2H-NMR T_1^(-1), T_(1P)^(-1) , and T_2^(-1); measurements. Cooperative fluctuations have been modelled using the continuum theory of the nematic state of liquid crystals. Chl a is found to decrease both the correlation length and the elastic constants in the DML bilayer.

A mismatch between the hydrophobic length of a lipid bilayer and that of an added protein has also been found to change the cooperative properties of the lecithin bilayer. Hydrophobic mismatch has been studied in a series GA' / lecithin bilayers. The dependence of 2H-NMR order parameters and relaxation rates on GA' concentration has been measured in selectively deuterated DML, dipalmitoyllecithin (DPL), and DSL systems. Order parameters, cooperative lengths, and elastic constants of the DML bilayer are most disrupted by GA', while the DSL bilayer is the least perturbed by GA'. Thus, it is concluded that the hydrophobic length of GA' best matches that of the DSL bilayer. Preliminary Raman spectroscopy and Differential Scanning Calorimetry experiments of GA' /lecithin systems support this conclusion. Accommodation of hydrophobic mismatch is used to rationalize the absence of H_(II) phase formation in GA' /DML systems and the observation of H_(II) phase in GA' /DPL and GA' /DSL systems.

1. J. W. Doane and D. L. Johnson, Chem. Phy3. Lett., 6, 291-295 (1970). 2. R. J. Pace and S. I. Chan, J. Chem. Phy3., 16, 4217-4227 (1982).

Entanglement negativity in the harmonic chain out of equilibrium

We study the entanglement in a chain of harmonic oscillators driven out of equilibrium by preparing the two sides of the system at different temperatures, and subsequently joining them together. The steady state is constructed explicitly and the logarithmic negativity is calculated between two adjacent segments of the chain. We find that, for low temperatures, the steady-state entanglement is a sum of contributions pertaining to left-and right-moving excitations emitted from the two reservoirs. In turn, the steady-state entanglement is a simple average of the Gibbs-state values and thus its scaling can be obtained from conformal field theory. A similar averaging behaviour is observed during the entire time evolution. As a particular case, we also discuss a local quench where both sides of the chain are initialized in their respective ground states.

Detection of usual and atypical aldehyde dehydrogenase alleles by mismatch amplification mutation assay

The genotypes of liver mitochondrial high-affinity aldehyde dehydrogenase-2 (ALDH2) are strongly associated with the drinking behavior and the alcohol liver diseases, since the individuals with atypical ALDH(2)(2) allele have higher levels of acetaldehyde in their plasma. The atypical ALDH(2)(2) allele has a nucleotide base transition (G-->A) in its exon 12. Based on this point mutation, we developed a rapid, reliable and inexpensive method, mismatch amplification mutation assay (MAMA), for the determination of human ALDH2 usual and atypical alleles. Two pairs of primers were designed for the amplification of the usual ALDH(2)(1) allele and the atypical ALDH(2)(2) allele, respectively. If the sample for the detection was heterozygous, it could be amplified by both of the primers. The product of polymerase chain reaction (PCR) of ALDH2 exon 12 could be easily screened by electrophoresis on a 2% agarose gel. The results of the MAMA method were further confirmed by sequencing. In the total of fifty samples from unrelated healthy Chinese Han people from Wuhan, China, the frequency of atypical ALDH(2)(2) allele was found to be 12%.

A new interface anisotropic potential of zinc-blende semiconductor interface induced by lattice mismatch

A new interface anisotropic potential, which is proportional to the lattice mismatch of interfaces and has no fitting parameter, has been deduced for (001) zinc-blende semiconductor interfaces. The comparison with other interface models is given for GaAs/AlAs and GaAs/InAs interfaces. The strong influence of the interface anisotropic potential on the inplane optical anisotropy of GaAs/AlGaAs low dimensional structures is demonstrated theoretically within the envelope function approximation.

Band crossing in isovalent semiconductor alloys with large size mismatch: First-principles calculations of the electronic structure of Bi and N incorporated GaAs

For large size- and chemical-mismatched isovalent semiconductor alloys, such as N and Bi substitution on As sites in GaAs, isovalent defect levels or defect bands are introduced. The evolution of the defect states as a function of the alloy concentration is usually described by the popular phenomenological band anticrossing (BAC) model. Using first-principles band-structure calculations we show that at the impurity limit the N-(Bi)-induced impurity level is above (below) the conduction- (valence-) band edge of GaAs. These trends reverse at high concentration, i.e., the conduction-band edge of GaAs1-xNx becomes an N-derived state and the valence-band edge of GaAs1-xBix becomes a Bi-derived state, as expected from their band characters. We show that this band crossing phenomenon cannot be described by the popular BAC model but can be naturally explained by a simple band broadening picture.

HIGH-RESOLUTION DLTS AND ITS APPLICATION TO LATTICE-MISMATCH-INDUCED DEEP LEVELS IN INGAP

A new method of differentiating the deep level transient spectroscopy (DLTS) signal is used to increase the resolution of conventional DLTS. Using this method, more than one single deep level with small differences in activation energy or capture cross section, which are often hard to determine by conventional DLTS, can be distinguished. A series of lattice-mismatched InxGa1-xP samples are measured by improved DLTS to determine accurately the activation energy of a lattice-mismatch-induced deep level. This level cannot be clearly determined using conventional DLTS because the two signals partly overlap each other. Both the signals are thought to originate from a phosophorus vacancy and lattice-mismatch-induced defect.

Adaptation of Dopamine Neurons' Mismatch Sensitivity Is not Compatible With Reinforcement Learning Theory

Recent electrophysical data inspired the claim that dopaminergic neurons adapt their mismatch sensitivities to reflect variances of expected rewards. This contradicts reward prediction error theory and most basal ganglia models. Application of learning principles points to a testable alternative interpretation-of the same data-that is compatible with existing theory.