Evolutionary Algorithm for the Placement of Fluid Power Valves on a Valve Stand

The choice of placement of fluid power valves on a valve stand and routing by pipes has an impact on operational costs. Choosing the right placement that provides optimum routing configuration or determining the optimum routing for a chosen placement are both computationally hard problems. An evolutionary algorithm (EA), to minimize operational costs while optimizing placement and routing of valves, is developed here. The best practices in the industry are abstracted and implemented in the EA. In this paper, the algorithm and its performance for examples with varying complexities are presented. Our results meet or exceed experienced designers’ solutions

Evolutionary Algorithm for the Placement of Fluid Power Valves on a Valve Stand

The choice of placement of fluid power valves on a valve stand and routing by pipes has an impact on operational costs. Choosing the right placement that provides optimum routing configuration or determining the optimum routing for a chosen placement are both computationally hard problems. An evolutionary algorithm (EA), to minimize operational costs while optimizing placement and routing of valves, is developed here. The best practices in the industry are abstracted and implemented in the EA. In this paper, the algorithm and its performance for examples with varying complexities are presented. Our results meet or exceed experienced designers’ solutions

Language Universals Engage Broca's Area

It is well known that natural languages share certain aspects of their design. For example, across languages, syllables like blif are preferred to lbif. But whether language universals are myths or mentally active constraints—linguistic or otherwise—remains controversial. To address this question, we used fMRI to investigate brain response to four syllable types, arrayed on their linguistic well-formedness (e.g., blif≻bnif≻bdif≻lbif, where ≻ indicates preference). Results showed that syllable structure monotonically modulated hemodynamic response in Broca's area, and its pattern mirrored participants' behavioral preferences. In contrast, ill-formed syllables did not systematically tax sensorimotor regions—while such syllables engaged primary auditory cortex, they tended to deactivate (rather than engage) articulatory motor regions. The convergence between the cross-linguistic preferences and English participants' hemodynamic and behavioral responses is remarkable given that most of these syllables are unattested in their language. We conclude that human brains encode broad restrictions on syllable structure

Repeatability of proton magnetic resonance spectroscopy of the brain at 7 T: effect of scan time on semi-localized by adiabatic selective refocusing and short-echo time stimulated echo acquisition mode scans and their comparison

Background: Proton magnetic resonance spectroscopy (MRS) provides a unique opportunity for in vivo measurements of the brain's metabolic profile. Two methods of mainstream data acquisition are compared at 7 T, which provides certain advantages as well as challenges. The two representative methods have seldom been compared in terms of measured metabolite concentrations and different scan times. The current study investigated proton MRS of the posterior cingulate cortex using a semi-localized by adiabatic selective refocusing (sLASER) sequence and a short echo time (TE) stimulated echo acquisition mode (sSTEAM) sequence, and it compared their reliability and repeatability at 7 T using a 32-channel head coil. Methods: Sixteen healthy subjects were prospectively enrolled and scanned twice with an off-bed interval between scans. The scan parameters for sLASER were a TR/TE of 6.5 s/32 ms and 32 and 48 averages (sLASER×32 and sLASER×48, respectively). The scan parameters for sSTEAM were a TR/TE of 4 s/5 ms and 32, 48, and 64 averages (sSTEAM4×32, sSTEAM4×48, and sSTEAM4×64, respectively) in addition to that with a TR/TE of 8 s/5 ms and 32 averages (sSTEAM8×32). Data were analyzed using LCModel. Metabolites quantified with Cramér-Rao lower bounds (CRLBs) >50% were classified as not detected, and metabolites quantified with mean or median CRLBs ≤20% were included for further analysis. The SNR, CRLBs, coefficient of variation (CV), and metabolite concentrations were statistically compared using the Shapiro-Wilk test, one-way ANOVA, or the Friedman test. Results: The sLASER spectra for N-acetylaspartate + N-acetylaspartylglutamate (tNAA) and glutamate (Glu) had a comparable or higher SNR than sSTEAM spectra. Ten metabolites had lower CRLBs than prefixed thresholds: aspartate (Asp), γ-aminobutyric acid (GABA), glutamine (Gln), Glu, glutathione (GSH), myo-inositol (Ins), taurine (Tau), the total amount of phosphocholine + glycerophosphocholine (tCho), creatine + phosphocreatine (tCr), and tNAA. Performance of the two sequences was satisfactory except for GABA, for which sLASER yielded higher CRLBs (≥18%) than sSTEAM. Some significant differences in CRLBs were noted, but they were ≤2% except for GABA and Gln. Signal averaging significantly lowered CRLBs for some metabolites but only by a small amount. Measurement repeatability as indicated by median CVs was ≤10% for Gln, Glu, Ins, tCho, tCr, and tNAA in all scans, and that for Asp, GABA, GSH, and Tau was ≥10% under some scanning conditions. The CV for GABA according to sLASER was significantly higher than that according to sSTEAM, whereas the CV for Ins was higher according to sSTEAM. An increase in signal averaging contribute little to lower CVs except for Ins. Conclusions: Both sequences quantified brain metabolites with a high degree of precision and repeatability. They are comparable except for GABA, for which sSTEAM would be a better choice

Comparison of Functional Free-Breathing Pulmonary 1H and Hyperpolarized 129Xe Magnetic Resonance Imaging in Pediatric Cystic Fibrosis

Rationale and Objectives: Phase resolved functional lung (PREFUL) magnetic resonance imaging (MRI) is a free-breathing 1H-based technique that produces maps of fractional ventilation (FV). This study compared ventilation defect percent (VDP) calculated using PREFUL to hyperpolarized (HP) 129Xe MRI and pulmonary function tests in pediatric cystic fibrosis (CF). Materials and Methods: 27 pediatric participants were recruited (mean age 13.0 ± 2.7), including 6 with clinically stable CF, 11 CF patients undergoing a pulmonary exacerbation (PEx), and 10 healthy controls. Spirometry was performed to measure forced expiratory volume in 1 second (FEV1), along with nitrogen multiple breath washout to measure lung clearance index (LCI). VDP was calculated from single central coronal slice PREFUL FV maps and the corresponding HP 129Xe slice. Results: The stable CF group had a normal FEV1 (p = 0.41) and elevated LCI (p = 0.007). The CF PEx group had a decreased FEV1 (p < 0.0001) and elevated LCI (p < 0.0001). PREFUL and HP 129Xe VDP were significantly different between the CF PEx and healthy groups (p < 0.05). In the stable CF group, PREFUL and HP 129Xe VDP were not significantly different from the healthy group (p = 0.18 and 0.08, respectively). There was a correlation between PREFUL and HP 129Xe VDP (R2 = 0.31, p = 0.004), and both parameters were significantly correlated with FEV1 and LCI. Conclusion: PREFUL MRI is feasible in pediatric CF, distinguishes patients undergoing pulmonary exacerbations compared to healthy subjects, and correlates with HP 129Xe MRI as well as functional measures of disease severity. PREFUL MRI does not require breath-holds and is straight forward to implement on any MRI scanner.The Hospital for Sick Children. Grant: Cystic Fibrosis Catalyst. Natural Sciences and Engineering Research Council of Canada. Grant Number: RGPIN 217015-2013. Canadian Institutes of Health Research. Grant Numbers: MOP 123431, PJT 153099, and PJT 376120. Mitacs

The effect of syllable hierarchy on behavior.

<p>As the stimulus became worse-formed on the syllable hierarchy, the proportion of errors increased selectively to monosyllables.</p

The effect of syllable hierarchy in sensorimotor speech areas.

<p>The syllable structure manipulation activated primary auditory cortex (A), and this effect was specifically due to the structure of monosyllables (B). Syllable structure also modulated hemodynamic response in motor areas (C), but these effects, significant at the larynx area, resulted in deactivation (D). Responses to monosyllables are plotted in blue; disyllables are indicated in red.</p

The effect of the syllable hierarchy on language areas (a), speech processing areas (sensorimotor and lexical, b) and other areas (c).

<p><u>Note</u>. For the hypothesized language regions (a), significance threshold is p<.05 (corrected); for the nonlinguistic speech regions (b), p<.001 (uncorrected); for all other regions (c), p<.0001 (uncorrected). Cluster extent for language areas is calculated at the .01 significance levels; all other clusters are calculated at the .001 level. All subthresholding trends are listed in italic font, for the purpose of showing the sign/direction of the activations. BA = Brodmann area; L = left hemisphere; R = Right Hemisphere; P = Posterior; A = Anterior, S = Superior; M = Middle; TMA  =  Transverse Temporal Gyrus; PC  =  Postcentral Gyrus; SMA  =  Supplementary Motor Area; pSTG  =  posterior Superior Temporal Gyrus; SMG  =  Supra Marginal Gyrus; *−p<.01; **−p<.001; ***−p<.0001.</p