Thermal Critical Points and Quantum Critical End Point in the Frustrated Bilayer Heisenberg Antiferromagnet

We consider the finite-temperature phase diagram of the $S = 1/2$ frustrated Heisenberg bilayer. Although this two-dimensional system may show magnetic order only at zero temperature, we demonstrate the presence of a line of finite-temperature critical points related to the line of first-order transitions between the dimer-singlet and -triplet regimes. We show by high-precision quantum Monte Carlo simulations, which are sign-free in the fully frustrated limit, that this critical point is in the Ising universality class. At zero temperature, the continuous transition between the ordered bilayer and the dimer-singlet state terminates on the first-order line, giving a quantum critical end point, and we use tensor-network calculations to follow the first-order discontinuities in its vicinity.Comment: 6 pages, 4 figures; supplemental material: 3 pages, 3 figures; v2: as publishe

Deep Learning: Our Miraculous Year 1990-1991

In 2020, we will celebrate that many of the basic ideas behind the deep learning revolution were published three decades ago within fewer than 12 months in our "Annus Mirabilis" or "Miraculous Year" 1990-1991 at TU Munich. Back then, few people were interested, but a quarter century later, neural networks based on these ideas were on over 3 billion devices such as smartphones, and used many billions of times per day, consuming a significant fraction of the world's compute.Comment: 37 pages, 188 references, based on work of 4 Oct 201

Learning to cycle : the influence of individual constraints and of the training bicycle

The present thesis aimed to investigate an important motor milestone in children’s life, the process of learning to cycle, more specifically to: 1) systematically review the intervention programs for learning to cycle; 2) investigate different constraints that influence this learning process; 3) create and implement a learning to cycle intervention, and compare the learning process between the balance bike (BB) and the bicycle with lateral training wheels (BTW); 4) analyse the BB’s cycling patterns and investigate if velocity is a control parameter; 5) compare the motor variability during the learning process with BB and BTW. The methodology included a systematic review, one web-survey, a longitudinal intervention, and two cross-sectional studies. The systematic review pointed that it should be adopted a progressive cycle learning strategy, primarily using training bicycles and simpler exercises. The survey identified differences in the age of learning to cycle (ALC) according to the: training bicycle used, with the BB's approach revealing the lowest ALC; birth decade, which has decreased since 1970-79; physical activity, with people more active learning to cycle earlier; and birth order, with the younger children learning earlier than only children. The “L2Cycle” program was applied to 25 children (6.08±1.19 years), having a success rate of 88% (100%-BB, 75%-BTW). BB’s children needed fewer days to cycle independently (self-launch, ride and brake). Seven BB’s cycle patterns were categorized. After six sessions, children explored more cycling patterns and increased their global velocities. The results support that velocity is a probable control parameter. During the learning process, the BB allowed a greater motor variability than the BTW, leading to a faster adaptation to the traditional bicycle, which is a potential reason for its greater learning efficiency.Esta tese teve como objetivo investigar um importante marco motor na vida da criança, o processo de aprender a andar de bicicleta, visando especificamente: 1) rever sistematicamente os programas de intervenção para fomentar esta aprendizagem; 2) investigar os diferentes constrangimentos que influenciam esta aprendizagem; 3) criar e implementar um programa de aprendizagem, comparando o processo de aprendizagem entre a bicicleta de equilíbrio (BE) e bicicleta com rodas laterais (BRL); 4) analisar os padrões de motores que existem na BE e investigar se a velocidade é um parâmetro de controlo; 5) comparar a variabilidade motora durante a aprendizagem com a BE e BRL. A metodologia incluiu uma revisão sistemática, um inquérito online, uma intervenção longitudinal e dois estudos transversais. A revisão sistemática apontou que deve ser adotada uma estratégia de aprendizagem progressiva, utilizando primeiramente bicicletas de treino e exercícios mais simples. O inquérito verificou diferenças na idade de aprendizagem (IA) de acordo com: a bicicleta de treino, com a abordagem da BE a revelar menor IA; década de nascimento, a qual decresceu desde 1970-79; atividade física, com pessoas mais ativas a aprendem mais cedo e; ordem de nascimento, com o irmão mais novo a aprender mais cedo que o filho único. O programa de aprendizagem “L2Cycle” foi aplicado a 25 crianças (6,08±1,19anos), revelando um sucesso de 88% (100%-BE, 75%-BRL). As crianças da BE necessitaram de menos dias para andar de bicicleta autonomamente (iniciar, pedalar em equilíbrio e travar). Foram categorizados sete padrões motores na BE. Após seis sessões as crianças exploraram mais padrões e aumentaram as suas velocidades globais. Os resultados suportam que a velocidade é um provável parâmetro de controlo. Durante a aprendizagem, a BE induziu uma maior variabilidade motora que a BRL, levando a adaptação mais rápida à bicicleta tradicional, o que é uma potencial razão para a sua maior eficiência de aprendizagem

Detect to Track and Track to Detect

Recent approaches for high accuracy detection and tracking of object categories in video consist of complex multistage solutions that become more cumbersome each year. In this paper we propose a ConvNet architecture that jointly performs detection and tracking, solving the task in a simple and effective way. Our contributions are threefold: (i) we set up a ConvNet architecture for simultaneous detection and tracking, using a multi-task objective for frame-based object detection and across-frame track regression; (ii) we introduce correlation features that represent object co-occurrences across time to aid the ConvNet during tracking; and (iii) we link the frame level detections based on our across-frame tracklets to produce high accuracy detections at the video level. Our ConvNet architecture for spatiotemporal object detection is evaluated on the large-scale ImageNet VID dataset where it achieves state-of-the-art results. Our approach provides better single model performance than the winning method of the last ImageNet challenge while being conceptually much simpler. Finally, we show that by increasing the temporal stride we can dramatically increase the tracker speed.Comment: ICCV 2017. Code and models: https://github.com/feichtenhofer/Detect-Track Results: https://www.robots.ox.ac.uk/~vgg/research/detect-track

Rating Prediction in Conversational Task Assistants with Behavioral and Conversational-Flow Features

Predicting the success of Conversational Task Assistants (CTA) can be critical to understand user behavior and act accordingly. In this paper, we propose TB-Rater, a Transformer model which combines conversational-flow features with user behavior features for predicting user ratings in a CTA scenario. In particular, we use real human-agent conversations and ratings collected in the Alexa TaskBot challenge, a novel multimodal and multi-turn conversational context. Our results show the advantages of modeling both the conversational-flow and behavioral aspects of the conversation in a single model for offline rating prediction. Additionally, an analysis of the CTA-specific behavioral features brings insights into this setting and can be used to bootstrap future systems

Learning to cycle: from training wheels to balance bike

Background: Learning to cycle is an important milestone in a child’s life, so it is important to allow them to explore cycling as soon as possible. The use of a bicycle with training wheels (BTW) for learning to cycling is an old approach practiced worldwide. Most recently, a new approach using the balance bike (BB) has received increased attention, and several entities believe that this could be most efficient. Drawing on the work of Bronfenbrenner (1995) and Newel (1986), this study aimed to analyse the effect of BB’s use on the learning process of cycling independently. Methods: Data were collected in Portugal from an online structured survey between November 2019 and June 2020. Results: A total of 2005 responses were obtained for adults and children (parental response). Results revealed that when the BB’s approach was used, learning age (LA) occurred earlier (M = 4.16 ± 1.34 years) than with the BTW’s approach (M = 5.97 ± 2.16 years) (p < 0.001); or than when there was only the single use of the traditional bicycle (M =7.27 ± 3.74 years) (p < 0.001). Conclusions: Children who used the BB as the first bike had a significantly lower LA than children who did not use it (p < 0.001). To maximize its effects, the BB should be used in the beginning of the learning process.info:eu-repo/semantics/publishedVersio