Miracle-dz/UniFAR-FTUs huggingface dataset:
Domains of analyticity and Lindstedt expansions of KAM tori in some dissipative perturbations of Hamiltonian systems

Conformally symplectic systems are characterized by the property that they transform a symplectic form into a multiple of itself. The limit of small dissipation, which is the object of the present study, is particularly interesting. We consider a family of conformally symplectic maps fμ,ε (very simple modifications, which we present, give results for differential equations) defined on a 2d-dimensional symplectic manifold M with exact symplectic form Ω; we assume that fμ,ε satisfies fμ,ε∗Ω=λ(ε)Ω. The d-dimensional parameter μ is called drift. We assume that λ(ε)=1+αεa+O(|ε|a+1), where a∈Z+, α∈C\{0}. We study the perturbative expansions and the domains of analyticity in ε near ε=0 of the parameterization of the quasi-periodic orbits of frequency ω (assumed to be Diophantine) and of the parameter μ. Notice that this is a singular perturbation, since any friction (no matter how small) reduces the set of quasi-periodic solutions in the system. We prove that the tori are analytic in a domain in the complex ε plane, obtained by taking from a ball centered at zero a sequence of smaller balls with center along smooth lines going through the origin. The radii of the excluded balls decrease faster than any power of the distance of the center to the origin. We state also a conjecture on the optimality of our results. The boundary of the domain is very thin, so that we can perform unique analytic continuation of the invariant tori along closed circles enclosing the points in the complement of the analyticity. We show that there is no monodromy of these continuations, either for the tori, for the invariant manifolds or for the drift. The proof is based on the following procedure. To find a quasi-periodic solution, one solves an invariance equation for the embedding of the torus, depending on the parameters of the family. Assuming that the frequency of the torus satisfies a Diophantine condition, under mild non-degeneracy assumptions, using a Lindstedt procedure we construct an approximate solution to all orders of the invariance equation describing the KAM torus. Starting from such approximate solution, we use an a posteriori KAM theorem to get the true solution of the invariance equation. This allows also the study of monogenic and Whitney differentiability properties of the extensions as well as the monodromy.
“That’s the biggest impact!” Pedagogical values of movies in ELT classrooms

Since many say watching movies can have a positive effect on language learning outcomes, this research was done to find out which skills movies can contribute most to, whether speaking, listening, reading, writing, vocabulary, grammar or cultural aspects. A qualitative research method was used for this study. This study was done to find out the teachers’ perceptions of using English movies in English Language Teaching (ELT) processes. Teachers from three different levels: primary, secondary, and senior high-school teachers were asked to answer a questionnaire set in accordance with the research topic. Five of them were senior high school teachers, two of them were junior high school teachers, and three of them were elementary school teachers. Creative interviews were also used as an additional data source. The results showed that most of the teachers agreed that movies play their biggest role and considerable advantages in developing cultural aspects and listening skills. Furthermore, some integration is possible between listening and speaking as well as with reading and writing because watching movies works better with integration of skills. Apparently, even though vocabulary can develop with this technique, grammar is not enhanced alone without being accompanied by writing.
Communication in Online Forums About the Experience and Management of Relational Uncertainty in Military Life

ABSTRACT Relational uncertainty is an undeniable aspect of military life, but the literature lacks knowledge about the lived experiences of military couples. We examined how individuals communicate in online forums about relational uncertainty in military life using a grounded theory approach to analyze 1,794 pages of threads. Results demonstrated that posters detected deception and/or recognized change, which led to volatile emotions, and ultimately prompted them to seek help for managing relational uncertainty. Posters dealt with their questions by engaging in self-care, justifying the partner’s behavior, postponing action, and doing relationship work. In reply, responders provided emotional support by offering comfort and reframing change. They provided informational support by recommending that posters acknowledge deception, take care of themselves, consider the partner’s perspective, defer major changes, and work on the relationship. These findings advance theorizing about relational uncertainty and social support; they also suggest guidelines for helping military couples manage relational uncertainty. Video abstract Read the transcript Watch the video on Vimeo
Microphones and Measurements

This paper presents the current status of an ongoing investigation of differences in formant estimates of vowels that may come about solely due to the circumstances of the recording of the speech material. The impact of the interplay between type and placement of microphone and room acoustics are to be examined for adult males and females across a number of vowel qualities. Furthermore, two estimation methods will be compared (LPC vs. manual). We present the pilot experiment that initiated the project along with a brief discussion of some relevant articles. The pilot experiment as well as the available results from other related experiments seem to indicate that different recording circumstances could induce apparent formant differences of a magnitude comparable to differences reported in some investigations
The Impact of Monetary Union on Macroeconomic Integration: Evidence from West Africa

Data from 19 African nations is used to investigate the hypothesis that monetary union-represented in this case by the CFA Franc Zone-augments the extent of macroeconomic integration. The paper covers two key dimensions of integration: the volume of bilateral trade, and the magnitude of cross-country business cycle correlation. Restricting our attention to a part of the world in which (for historical reasons) monetary union membership is exogenous to economic characteristics, we can test whether the large single-currency effects claimed by A. Rose apply within a sample of less developed countries. Copyright (c) The London School of Economics and Political Science 2005.
Dynamic Adjustment of the Chaos-Based Security in Real-Time Energy Harvesting Sensors

Wireless Sensor Networks (WSNs) are a growing field of research since they are used in many applications. Nevertheless, they are subject to many requirements such as real-time constraints, energy limitations, and security requirements for the communications. Energy Harvesting is a new paradigm in WSNs: sensor nodes are powered by energy harvested from the ambient, rather than by non-rechargeable batteries which permits a potentially perpetual operation. However, energy harvesting poses new challenges in the design of WSNs, in that energy availability fluctuates over the time. In this paper, we investigate the following fundamental question: how should the harvested energy be managed to guarantee data security in all circumstances? Our contributions in this paper are twofold: First, we propose the Deadline Mechanism to dynamically cope with energy shortage and guarantee the highest possible quality of protection by the use of different encryption algorithms. Second, we design a new chaos based cryptosystem suitable for WSNs. Indeed, the proposed encryption/decryption scheme is robust against all known attacks. Experiments show that it is at least 7 times faster than the AES algorithm and also, faster than many chaos based cryptosystems of the literature. Our objective is to identify low-complexity policies that achieve close-to-optimal performance, in terms of maximizing the average long-term importance of the reported data.
Lessons Learned from Online Classification of Photo-Realistic Computer Graphics and Photographs

We presented a set of physics motivated features for classifying photographic and computer graphic images in our previous work [1]. We also deployed an online demo system for distinguishing photographic and computer graphic images in October 2005 [2], which features our geometry classifier, together with the wavelet classifier, and the cartoon classifier. On the first anniversary of its launch, we have received 1582 submitted images, through which we perform an analysis on the user behavior, the image set characteristics, and the classifier performance. We observe that online users do not provide clear judgments for about 80% of the submitted images, confirming the challenge in distinguishing photo-realistic computer graphics images from natural photographs. We also found the accuracy of our classifiers over the online submission set is consistent with that computed over an offline data set. Finally, in order to improve the online computational speed of our classifier, we perform feature selection and reduction, cutting the response time from 152 seconds to 24 seconds per image, while keeping the accuracy almost unchanged.
Rolling tachyon with electric and magnetic fields: T-duality approach

We study the decay of unstable D$p$-branes when the world-volume gauge field is turned on. We obtain the relevant Dp-brane boundary state with electric and magnetic fields by boosting and rotating the rolling tachyon boundary state of a D(p-1)-brane and then T-dualizing along one of the transverse directions. A simple recipe to turn on the gauge fields in the boundary state is given. We find that the effect of the electric field is to parametrically enhance coupling of closed string oscillation modes along the electric field direction and provide an intuitive understanding of the result in the T-dualized picture. We also analyze the system by using the effective field theory and compare the result with the boundary state approach.
Being bilingual, being a reader: Prekindergarten dual language learners’ reading identities

This study explores the interplay between early reading, identity and bilingualism. Reading identities, or understandings about what reading is and whom one is as a reader, have been linked to reading achievement and the development of reading skills. Only a small portion of the overall research on reading identities has included dual language learners. This exploratory study provides a description of the reading identities of three dual language learners in prekindergarten. Data include child-centered interviews, child and classroom observations, teacher interviews and a family questionnaire. Methods centered on the use of child-oriented data collection protocols, and the inclusion of children in the interpretation of their own work and language. Through the exploration of three cases, this study documents the ways that reading identities were constructed, taken up and expressed by the participants. This study provides evidence that dual language learners are actively constructing ideas about reading, bilingualism/biliteracy, and whom they are as readers as they learn to read. These findings show that framing early reading in an identity perspective presents opportunities to look more holistically at the language and reading practices of dual language learners as they learn to read and navigate two or more languages at home and school.
Role of gender and linguistic background on students' learning styles in an inter-professional science unit

Inter-professional education is the current trend in health related degree programs. This study aimed to determine the role of gender and linguistic background on students’ learning styles in a science unit. Human Biology 1 is the inter-professional unit taken by Nursing, Physiotherapy and Exercise Science students at the Australian Catholic University. Students were invited to participate in a survey, which consisted of questions requesting demographic information and their learning preference(s) based on the “VARK” sensory modalities: visual, aural, reading-writing, and kinesthetic; an English Language Acculturation scale was also used. Analysis of responses indicated an overall student preference for multiple learning styles: 47% of females and 42% of males stated that they were quad-modal learners, with approximately a quarter of either gender preferring uni-modal learning style. Of the 26% of students being uni-modal learners, 25 were from ESB and 35 from NESB; and, of the 45% being quad-modal learners, 50 were from ESB and 54 from NESB. This study provides evidence that students had similar learning preferences in the science unit, irrespective of gender or linguistic background, and that more students can be reached through multi-modal instruction in an inter-professional science unit.
Gravitational energy in spherical symmetry.

Various properties of the Misner-Sharp spherically symmetric gravitational energy E are established or reviewed. In the Newtonian limit of a perfect fluid, E yields the Newtonian mass to leading order and the Newtonian kinetic and potential energy to the next order. For test particles, the corresponding H\'aj\'{\i}\ifmmode \check{c}\else \v{c}\fi{}ek energy is conserved and has the behavior appropriate to energy in the Newtonian and special-relativistic limits. In the small-sphere limit, the leading term in E is the product of volume and the energy density of the matter. In vacuo, E reduces to the Schwarzschild energy. At null and spatial infinity, E reduces to the Bondi-Sachs and Arnowitt-Deser-Misner energies, respectively. The conserved Kodama current has charge E. A sphere is trapped if Eg1/2r, marginal if E=1/2r, and untrapped if E1/2r, where r is the areal radius. A central singularity is spatial and trapped if Eg0, and temporal and untrapped if E0. On an untrapped sphere, E is nondecreasing in any outgoing spatial or null direction, assuming the dominant energy condition. It follows that E\ensuremath{\ge}0 on an untrapped spatial hypersurface with a regular center, and E\ensuremath{\ge}1/2${\mathit{r}}_{0}$ on an untrapped spatial hypersurface bounded at the inward end by a marginal sphere of radius ${\mathit{r}}_{0}$. All these inequalities extend to the asymptotic energies, recovering the Bondi-Sachs energy loss and the positivity of the asymptotic energies, as well as proving the conjectured Penrose inequality for black or white holes. Implications for the cosmic censorship hypothesis and for general definitions of gravitational energy are discussed. \textcopyright{} 1996 The American Physical Society.
A comparative study of JPEG2000, AVC/H.264, and HD photo

In this paper, we report a study evaluating rate-distortion performance between JPEG 2000, AVC/H.264 High 4:4:4 Intra and HD Photo. A set of ten high definition color images with different spatial resolutions has been used. Both the PSNR and the perceptual MSSIM index were considered as distortion metrics. Results show that, for the material used to carry out the experiments, the overall performance, in terms of compression efficiency, are quite comparable for the three coding approaches, within an average range of ±10% in bitrate variations, and outperforming the conventional JPEG.
At Least I Tried: The Relationship between Regulatory Focus and Regret Following Action vs. Inaction

Regret is an unpleasant feeling that may arise following decisions that ended poorly, and may affect the decision-maker's well-being and future decision making. Some studies show that a decision to act leads to greater regret than a decision not to act when both resulted in failure, because the latter is usually the norm. In some cases, when the norm is to act, this pattern is reversed. We suggest that the decision maker's regulatory focus, affects regret after action or inaction. Specifically, promotion-focused individuals, who tend to be more proactive, view action as more normal than prevention-focused individuals, and therefore experience regulatory fit when an action decision is made. Hence, we hypothesized that promotion-focused individuals will feel less regret than prevention-focused individuals when a decision to act ended poorly. In addition, we hypothesized that a trigger for change implied in the situation, decreases the level of regret following action. We tested our hypotheses on a sample of 330 participants enrolled in an online survey. The participants received six decision scenarios, in which they were asked to evaluate the level of regret following action and inaction. Individual regulatory focus was measured by two different scales. Promotion-focused individuals attributed less regret than prevention-focused individuals to action decisions. Regret following inaction was not affected by regulatory focus. In addition, a trigger for change decreases regret following action. Orthodox people tend to attribute more regret than non-orthodox to a person who made an action decision. The results contribute to the literature by showing that not only the situation but also the decision maker's orientation affects the regret after action vs. inaction.
Accretion in stellar clusters and the IMF

We present a simple physical mechanism that can account for the observed stellar mass spectrum for masses $\ms \simgreat 0.5 \solm$. The model depends solely on the competitive accretion that occurs in stellar clusters where each star's accretion rate depends on the local gas density and the square of the accretion radius. In a stellar cluster, there are two different regimes depending on whether the gas or the stars dominate the gravitational potential. When the cluster is dominated by cold gas, the accretion radius is given by a tidal-lobe radius. This occurs as the cluster collapses towards a $\rho\propto R^{-2}$ distribution. Accretion in this regime results in a mass spectrum with an asymptotic limit of $\gamma=-3/2$ (where Salpeter is $\gamma=-2.35$). Once the stars dominate the potential and are virialised, which occurs first in the cluster core, the accretion radius is the Bondi-Hoyle radius. The resultant mass spectrum has an asymptotic limit of $\gamma=-2$ with slightly steeper slopes ($\gamma\approx-2.5$) if the stars are already mass-segr egated. Simulations of accretion onto clusters containing 1000 stars show that as expected, the low-mass stars accumulate the majority of their masses during the gas dominated phase whereas the high-mass stars accumulate the majority of their massed during the stellar dominated phase. This results in a mass spectrum with a relatively shallow $\gamma\approx 3/2$ power-law for low-mass stars and a steeper, power-law for high-mass stars $ -2.5\simless\gamma\le -2$. This competitive accretion model also results in a mass segregated cluster.
IMPACT OF VALUE-ADDED ACTIVITIES OF EARLY-STAGE VENTURE CAPITALISTS ON THE NUMBER OF NEW INVESTORS IN SUCCESSIVE FINANCIAL ROUNDS OF VENTURES 10

We integrate agency and resource dependence theories to explain how the value-added activities of early-stage venture capitalists affect the number of new investors in successive financial rounds of ventures. Drawn on a sample of 227 ventures, we find a positive impact of participation in CEO replacement and creation of linkages to potential investors and negative impact of advising in business plan preparation.
A Generalized Sequential Bonferroni Procedure Using Smoothed Weights for Genome-Wide Association Studies Incorporating Information on Hardy-Weinberg Disequilibrium among Cases

Background/Objectives: For genome-wide association studies (GWAS) with case-control designs, one of the most widely used association tests is the Cochran-Armitage (CA) trend test assuming an additive mode of inheritance. The CA trend test often has higher power than other association tests under additive and multiplicative disease models. However, it can have very low power under a recessive disease model in GWAS. Although tests (such as MAX3) robust to different genetic models have been developed, they often have relatively lower power than the CA trend test under additive and multiplicative models. The goal of this study is to propose an efficient method that not only has higher power than the CA trend test under dominant and recessive models but also maintains the power of the CA trend test under additive and multiplicative models. Methods: We employed the generalized sequential Bonferroni (GSB) procedure of Holm to incorporate information from a Hardy-Weinberg disequilibrium (HWD) test into the CA trend test based on estimating weights from the p values of the HWD test. We proposed to smooth the weights to reduce possible noise. Results and Conclusions: Results from extensive simulation studies showed that the proposed GSB procedure can achieve the goal described above.
Vibratory feedback for artificial hands

One of the capability of a prosthetic hand device that is highly preferred is that it should be able to mimic the functionality of the lost arm, and that loss includes the tactile sensory system. A miniature DC motor has been identified to be the best haptic actuator to deliver the required sensory feedback. Experiments and simulations were carried out to predict the transient responses, driving frequencies as well as vibration amplitude of the motor. The results have shown that the motor is reliable in matching the optimum frequency response of the mechanoreceptors in the residual arm, which is important in providing an efficient supplementary sensation.
Blind estimation of bit and block error probabilities using soft information

We consider the problem of estimating the bit error probability (BEP) and the block error probability (BLEP) in digital communication systems in a blind manner, i.e., without knowledge of the transmitted data. We propose estimators based on soft information and show that they outperform conventional non-blind estimators, which know the transmitted data. We study the performance of these estimators and provide conditions that guarantee that our BEP estimator is the minimum variance unbiased estimator. For the Gaussian case we derive the Cramér-Rao lower bound for BEP estimation and show that an efficient estimator does not exist. Furthermore, we derive simple lower and upper bounds for the BLEP estimator. Our results are numerically corroborated using Monte Carlo simulations.