Signatures of Dynamical Tunneling in the Wave function of a Soft-Walled Open Microwave Billiard

Evidence for dynamical tunneling is observed in studies of the transmission, and wave functions, of a soft-walled microwave cavity resonator. In contrast to previous work, we identify the conditions for dynamical tunneling by monitoring the evolution of the wave function phase as a function of energy, which allows us to detect the tunneling process even under conditions where its expected level splitting remains irresolvable.Comment: 5 pages, 5 figure

An Investigation of Coach Behaviors, Goal Motives, and Implementation Intentions as Predictors of Well-Being in Sport

The present study aimed to expand upon Smith, Ntoumanis, and Duda’s (2007) research by investigating the influence of coach behaviors and implementation intentions on goal striving in sport. Structural equation modeling analysis with a sample of 108 athletes revealed coach behaviors as predictors of goal motives, which in turn predicted psychological well-being after 8 weeks. Supplementary regression analyses showed no interaction between autonomous goal motives and implementation intentions; however, a synergistic effect was identified for controlled goal motives such that controlled motives furnished with implementation intentions resulted in lower well-being than controlled motives alone. In further analyses, the motives underlying an implementation intention were found to mediate the paths from goal motives to well-being. The findings are discussed in terms of the roles played by goal motives, implementation intentions, and implementation intention motives during goal striving

Linking brain-wide multivoxel activation patterns to behaviour: Examples from language and math

A key goal of cognitive neuroscience is to find simple and direct connections between brain and behaviour. However, fMRI analysis typically involves choices between many possible options, with each choice potentially biasing any brain-behaviour correlations that emerge. Standard methods of fMRI analysis assess each voxel individually, but then face the problem of selection bias when combining those voxels into a region-of-interest, or ROI. Multivariate pattern-based fMRI analysis methods use classifiers to analyse multiple voxels together, but can also introduce selection bias via data-reduction steps as feature selection of voxels, pre-selecting activated regions, or principal components analysis. We show here that strong brain-behaviour links can be revealed without any voxel selection or data reduction, using just plain linear regression as a classifier applied to the whole brain at once, i.e. treating each entire brain volume as a single multi-voxel pattern. The brain-behaviour correlations emerged despite the fact that the classifier was not provided with any information at all about subjects\u27 behaviour, but instead was given only the neural data and its condition-labels. Surprisingly, more powerful classifiers such as a linear SVM and regularised logistic regression produce very similar results. We discuss some possible reasons why the very simple brain-wide linear regression model is able to find correlations with behaviour that are as strong as those obtained on the one hand from a specific ROI and on the other hand from more complex classifiers. In a manner which is unencumbered by arbitrary choices, our approach offers a method for investigating connections between brain and behaviour which is simple, rigorous and direct. © 2010 Elsevier Inc

Impurity effects on the band structure of one-dimensional photonic crystals: Experiment and theory

We study the effects of single impurities on the transmission in microwave realizations of the photonic Kronig-Penney model, consisting of arrays of Teflon pieces alternating with air spacings in a microwave guide. As only the first propagating mode is considered, the system is essentially one dimensional obeying the Helmholtz equation. We derive analytical closed form expressions from which the band structure, frequency of defect modes, and band profiles can be determined. These agree very well with experimental data for all types of single defects considered (e.g. interstitial, substitutional) and shows that our experimental set-up serves to explore some of the phenomena occurring in more sophisticated experiments. Conversely, based on the understanding provided by our formulas, information about the unknown impurity can be determined by simply observing certain features in the experimental data for the transmission. Further, our results are directly applicable to the closely related quantum 1D Kronig-Penney model.Comment: 16 pages, 7 figure

An efficient Fredholm method for calculation of highly excited states of billiards

A numerically efficient Fredholm formulation of the billiard problem is presented. The standard solution in the framework of the boundary integral method in terms of a search for roots of a secular determinant is reviewed first. We next reformulate the singularity condition in terms of a flow in the space of an auxiliary one-parameter family of eigenproblems and argue that the eigenvalues and eigenfunctions are analytic functions within a certain domain. Based on this analytic behavior we present a numerical algorithm to compute a range of billiard eigenvalues and associated eigenvectors by only two diagonalizations.Comment: 15 pages, 10 figures; included systematic study of accuracy with 2 new figures, movie to Fig. 4, http://www.quantumchaos.de/Media/0703030media.av

Willing and able: action-state orientation and the relation between procedural justice and employee cooperation

Existing justice theory explains why fair procedures motivate employees to adopt cooperative goals, but it fails to explain how employees strive towards these goals. We study self-regulatory abilities that underlie goal striving; abilities that should thus affect employees’ display of cooperative behavior in response to procedural justice. Building on action control theory, we argue that employees who display effective self-regulatory strategies (action oriented employees) display relatively strong cooperative behavioral responses to fair procedures. A multisource field study and a laboratory experiment support this prediction. A subsequent experiment addresses the process underlying this effect by explicitly showing that action orientation facilitates attainment of the cooperative goals that people adopt in response to fair procedures, thus facilitating the display of actual cooperative behavior. This goal striving approach better integrates research on the relationship between procedural justice and employee cooperation in the self-regulation and the work motivation literature. It also offers organizations a new perspective on making procedural justice effective in stimulating employee cooperation by suggesting factors that help employees reach their adopted goals

Perception of American English /r/ and /U by Mandarin speakers: Influences of phonetic identification and category goodness

Abstract: This study examined Mandarin speakers' perception of American English /r/and ill. Eighteen /ra/ and ila'tokens were used that varied in F2 and F3 onset frequencies. Stimuli were identified as the lu/. /ml or /I/ of Mandarin, and were rated for goodness. The similarity of pairs of stimuli was also evaluated. Multi-dimensional scaling (MDS) analyses of similarit) ratings revealed that perception differed substantially from American speakers listening to the same stimuli, indicating the use of native-language representations in the perception of a non-native language. Young infants are able to discriminate phonemic contrasts of both their native language and non-native languages. With continued linguistic experience, sensitivity to non-native contrasts weakens, while sensitivity to native language contrasts is enhanced (1). Language-specific experience not only influences the perceptual organization at the boundaries between speech categories, but within categories as well The current study addressed the non-native perception of American English ir/ and ill by Mandarin speakers. The ill in American English is acoustically and phonetically similar to that of Mandarin. In contrast, ir/ is not a phoneme in Mandarin. Therefore, Mandarin speakers were expected to rely on representations of phonemes in their native language to perceive this non-native sound. The nature of these representations, and whether perception of /I/ is similar to that of Americans, remained questions for the research to answer, thereby providing an example of the perceptual impact of linguistic experience. METHOD Stimuli were 18 synthetic /ra/ and /la/ tokens from Ameiican English which varied in F2 and F3 onset frequencies in 200-me1 steps. Twenty-one native speakers of Mandarin, students in Taiwan, participated in two sessions. In the first session, the initial phoneme of each token was identified and rated for goodness on a 7-point scale. Pilot work revealed that Mandarin speakers classified the tokens as Mandarin /la/, /ua/, and /ma/, so identification was restricted to these phonemes. In the second session, participants rated the similarity of paired tokens on a 7-point scale. Similarity ratings were submitted to MDS to create a perceptual map where the distance between any two tokens corresponded to perceived similarity. [For additional details about procedures and stimuli, see Iverson and Kuhl(5).] RESULTS AND DISCUSSION Identification performance and goodness ratings (top), as well as MDS solutions (bottom), are summarized in The right panel of 206

Anomalous Behavior Of The Complex Conductivity Of Y_{1-x}Pr_xBa_2Cu_3O_7 Observed With THz Spectroscopy

We have measured the electrodynamic properties of Y_{1-x}Pr_xBa_2Cu_3O_7 single crystal thin films as a function of temperature using coherent THz-time-domain spectroscopy. We obtain directly the complex conductivity $\sigma=\sigma_1+i\sigma_2$, the London penetration depth $\lambda_L$, the plasma frequency $\omega_p$, and the quasiparticle scattering rate $1/\tau$. We find that $1/\tau$ drops exponentially rapidly with $T$ below the critical temperature in {\em all} the superconducting samples, implying that this behavior is a {\em signature} of high-$T_c$ superconductivity. The plasma frequency decreases with increasing Pr content, providing evidence that Pr depletes carriers, leaving the CuO planes {\em underdoped}. Both the conductivity in the THz region and the dc resistivity yield evidence for the opening of a spin gap {\em above} $T_c$.Comment: 9 pages, REVTEX 3.

Comparison of mesospheric winds from a high-altitude meteorological analysis system and meteor radar observations during the boreal winters of 2009–2010 and 2012–2013

We present a study of horizontal winds in the mesosphere and lower thermosphere (MLT) during the boreal winters of 2009–2010 and 2012–2013 produced with a new high-altitude numerical weather prediction (NWP) system. This system is based on a modified version of the Navy Global Environmental Model (NAVGEM) with an extended vertical domain up to ∼116 km altitude coupled with a hybrid four-dimensional variational (4DVAR) data assimilation system that assimilates both standard operational meteorological observations in the troposphere and satellite-based observations of temperature, ozone and water vapor in the stratosphere and mesosphere. NAVGEM-based MLT analyzed winds are validated using independent meteor radar wind observations from nine different sites ranging from 69°N–67°S latitude. Time-averaged NAVGEM zonal and meridional wind profiles between 75 and 95 km altitude show good qualitative and quantitative agreement with corresponding meteor radar wind profiles. Wavelet analysis finds that the 3-hourly NAVGEM and 1-hourly radar winds both exhibit semi-diurnal, diurnal, and quasi-diurnal variations whose vertical profiles of amplitude and phase are also in good agreement. Wavelet analysis also reveals common time-frequency behavior in both NAVGEM and radar winds throughout the Northern extratropics around the times of major stratospheric sudden warmings (SSWs) in January 2010 and January 2013, with a reduction in semi-diurnal amplitudes beginning around the time of a mesospheric wind reversal at 60°N that precedes the SSW, followed by an amplification of semi-diurnal amplitudes that peaks 10–14 days following the onset of the mesospheric wind reversal. The initial results presented in this study demonstrate that the wind analyses produced by the high-altitude NAVGEM system accurately capture key features in the observed MLT winds during these two boreal winter periods.</p

An Orientation Program for Vertical Transfers in Engineering and Engineering Technology

This paper reports on a scholarship program funded by the National Science Foundation that focuses on students who transfer at the 3rd -year level from 2-year schools to the engineering and engineering technology BS programs at our university. The objectives of the program are to: (i) expand and diversify the engineering/technology workforce of the future, (ii) develop linkages and articulations with 2-year schools and their S-STEM (Scholarships in Science, Technology, Engineering and Mathematics) programs, (iii) provide increased career opportunities and job placement rates through mandatory paid co-op experiences, and (iv) serve as a model for other universities to provide vertical transfer students access to the baccalaureate degree. The program is in its third year. It recruited its first group of 25 students in Fall 2017, and another group of 27 students in Fall 2018. We hope to recruit 26 more students in Fall 2019 for a total of 78 vertical transfers. The goal is to retain and graduate at least 95% of these scholars. To enhance the success of these scholars, a zero-credit six-week orientation course was developed in Fall 2017 focusing on four dimensions of student wellness: academic, financial, social, and personal. This paper describes the development of this course, its content, and the modifications that were made to the course for Fall 2018. The paper will also address the research conducted in order to generate knowledge about the program elements that will be essential for the success of vertical transfer programs at other universities. Two research instruments are described: an online survey and a focus group interview that were developed, and administered to the transfer scholars in their first year. Initial findings concerning students’ experiences at their 2-year schools, their reason for transferring, their experience in transferring as well as their initial conceptions of what life at a 4-year institution will be like are presented