Quantitative analysis of pixel crosstalk in AMOLED displays

The resolution of organic light-emitting diode (OLED) displays is increasing steadily as these displays are adopted for mobile and virtual reality (VR) devices. This leads to a stronger pixel crosstalk effect, where the neighbors of active pixels unintentionally emit light due to a lateral electric current between the pixels. Recently, the crosstalk was quantified by measuring the current flowing through the common hole transport layer between the neighboring pixels and comparing it to the current through the active pixel diode. The measurements showed that the crosstalk is more crucial for low light levels. In such cases, the intended and parasitic currents are similar. The simulations performed in this study validated these measurement results. By simulations, we quantify the crosstalk current through the diode. The luminous intensity can be calculated with the measured current efficiency of the diodes. For low light levels, the unintended luminance can reach up to 40% of the intended luminance. The luminance due to pixel crosstalk is perceivable by humans. This effect should be considered for OLED displays with resolutions higher than 300 PPI

Quantum Advantage for All

We show that the algorithmic complexity of any classical algorithm written in a Turing-complete programming language polynomially bounds the number of quantum bits that are required to run and even symbolically execute the algorithm on a quantum computer. In particular, we show that any classical algorithm $A$ that runs in $\mathcal{O}(f(n))$ time and $\mathcal{O}(g(n))$ space requires no more than $\mathcal{O}(f(n)\cdot g(n))$ quantum bits to execute, even symbolically, on a quantum computer. With $\mathcal{O}(1)\leq\mathcal{O}(g(n))\leq\mathcal{O}(f(n))$ for all $n$, the quantum bits required to execute $A$ may therefore not exceed $\mathcal{O}(f(n)^2)$ and may come down to $\mathcal{O}(f(n))$ if memory consumption by $A$ is bounded by a constant. Our construction works by encoding symbolic execution of machine code in a finite state machine over the satisfiability-modulo-theory (SMT) of bitvectors, for modeling CPU registers, and arrays of bitvectors, for modeling main memory. The FSM is linear in the size of the code, independent of execution time and space, and represents the reachable machine states for any given input. The FSM may be explored by bounded model checkers using SMT and SAT solvers as backend. However, for the purpose of this paper, we focus on quantum computing by unrolling and bit-blasting the FSM into (1)~satisfiability-preserving quadratic unconstrained binary optimization (QUBO) models targeting adiabatic forms of quantum computing such as quantum annealing, and (2)~semantics-preserving quantum circuits (QCs) targeting gate-model quantum computers. With our compact QUBOs, real quantum annealers can now execute simple but real code even symbolically, yet only with potential but no guarantee for exponential speedup, and with our QCs as oracles, Grover's algorithm applies to symbolic execution of arbitrary code, guaranteeing at least in theory a quadratic speedup

Choice matters: Pupils' stress regulation, brain development and brain function in an outdoor education project

Abstract Background Education outside the classroom (EOtC) is considered beneficial to children's physical and mental health. Especially, stress resilience has been linked to nature experience. Aims This study experimentally explored the effects of pupils' autonomy support (AUT) and physical activity (PA) on their biological stress responses and brain development in EOtC. Sample The study comprised 48 fifth and sixth graders. Methods The intervention consisted of one day/week taught in a forest over one school year. Structural magnetic resonance imaging (MRI) was conducted at the beginning and the end of the school year, functional MRI under a stress condition at the end. Regions of interest were amygdala, hippocampus and the anterior cingulate cortex (ACC). All other measures were obtained at the beginning, at mid-term and at the end of the school year. PA was measured using accelerometry. Cortisol levels were obtained three times during the examined school days. AUT was measured with a paper-based survey. Data were analysed using Bayesian multivariate models. Results EOtC students exhibit more efficient regulation of biological stress-reactivity and show a reduction of cortisol over the day associated with light PA in the forest. Cortisol is further associated with amygdala activation in the stress condition. Cerebral structural change is best explained by age; however, AUT has a positive direct effect on the maturation of the ACC, which is stronger in EOtC. Conclusions Our results support the idea that autonomy supportive teaching fosters cerebral maturation and that EOtC can have a positive effect on biological stress regulation.publishedVersio

Quantitative relaxation of concurrent data structures

There is a trade-off between performance and correctness in implementing concurrent data structures. Better performance may be achieved at the expense of relaxing correctness, by redefining the semantics of data structures. We address such a redefinition of data structure semantics and present a systematic and formal framework for obtaining new data structures by quantitatively relaxing existing ones. We view a data structure as a sequential specification S containing all "legal" sequences over an alphabet of method calls. Relaxing the data structure corresponds to defining a distance from any sequence over the alphabet to the sequential specification: the k-relaxed sequential specification contains all sequences over the alphabet within distance k from the original specification. In contrast to other existing work, our relaxations are semantic (distance in terms of data structure states). As an instantiation of our framework, we present two simple yet generic relaxation schemes, called out-of-order and stuttering relaxation, along with several ways of computing distances. We show that the out-of-order relaxation, when further instantiated to stacks, queues, and priority queues, amounts to tolerating bounded out-of-order behavior, which cannot be captured by a purely syntactic relaxation (distance in terms of sequence manipulation, e.g. edit distance). We give concurrent implementations of relaxed data structures and demonstrate that bounded relaxations provide the means for trading correctness for performance in a controlled way. The relaxations are monotonic which further highlights the trade-off: increasing k increases the number of permitted sequences, which as we demonstrate can lead to better performance. Finally, since a relaxed stack or queue also implements a pool, we actually have new concurrent pool implementations that outperform the state-of-the-art ones

Approximate audio processing in an audio graph for interactive music systems

Interactive music systems are highly dynamic systems that combine audio processing and control in real-time, and they often have to work on soft real-time platforms, where no stringent real-time guarantees can be upheld. We present here an overhead-aware online degradation algorithm that find a tradeoff between quality and lateness for the processing nodes of a dynamic audio graph. We show that we can scale to thousands of nodes

Severe immune dysregulation with neurological impairment and minor bone changes in a child with spondyloenchondrodysplasia due to two novel mutations in the ACP5 gene

Spondyloenchondrodysplasia (SPENCD) is a rare skeletal dysplasia, characterized by metaphyseal lesions, neurological impairment and immune dysregulation associated with lupus-like features. SPENCD is caused by biallelic mutations in the ACP5 gene encoding tartrate-resistant phosphatase. We report on a child, who presented with spasticity, multisystem inflammation, autoimmunity and immunodeficiency with minimal metaphyseal changes due to compound heterozygosity for two novel ACP5 mutations. These findings extend the phenotypic spectrum of SPENCD and indicate that ACP5 mutations can cause severe immune dysregulation and neurological impairment even in the absence of metaphyseal dysplasia

Patients' perspective on emergency treatment of ophthalmologic diseases during the first phase of SARS-CoV2 pandemic in a tertiary referral center in Germany - the COVID-DETOUR questionnaire study

Background During the first wave of the COVID-19 pandemic, the need of treatment of urgent ophthalmological diseases and the possible risk of a SARS-CoV-2 infection had to be weighed against each other. In this questionnaire study, we aimed to analyze potential barriers and patients' health beliefs during and after the lockdown early 2020 in a tertiary referral center in Kiel, Germany. Results Ninety-three patients were included, 43 in subgroup A (before April 20th) and 50 in subgroup B (April 20th or later). Retinal disorders were the most common causes for admission (approximately 60%).. Only 8 patients (8.6%) experienced a delay between their decision to visit a doctor until the actual examination. Every fourth patient was afraid of a COVID-19 infection, and expected a higher likelihood for an infection at the hospital. Patients with comorbidities tended to be more likely to be afraid of an infection (correlation coefficient 0.183, p = 0.0785) and were significantly more likely to be concerned about problems with organizing follow-up care (corr. Coefficient 0.222, p = 0.0328). Higher age was negatively correlated with fear of infection (corr. Coefficient - 0.218, p-value 0.034). Conclusion In this questionnaire study, only a minority of patients indicated a delay in treatment, regardless of whether symptoms occurred before or after the lockdown before April 20th, 2020. While patients with comorbidities were more concerned about infection and problems during follow-up care, patients of higher age - who have a higher mortality - were less afraid. Protection of high-risk groups should be prioritized during the SARS-CoV-2 pandemic. Trial registration The study was registered as DRKS00021630 at the DRKS (Deutsches Register Klinischer Studien) before the conduction of the study on May 5th, 2020