291 research outputs found
Unboxed data constructors -- or, how cpp decides a halting problem
We propose a new language feature for ML-family languages, the ability to
selectively *unbox* certain data constructors, so that their runtime
representation gets compiled away to just the identity on their argument.
Unboxing must be statically rejected when it could introduce *confusions*,
that is, distinct values with the same representation.
We discuss the use-case of big numbers, where unboxing allows to write code
that is both efficient and safe, replacing either a safe but slow version or a
fast but unsafe version.
We explain the static analysis necessary to reject incorrect unboxing
requests.
We present our prototype implementation of this feature for the OCaml
programming language, discuss several design choices and the interaction with
advanced features such as Guarded Algebraic Datatypes.
Our static analysis requires expanding type definitions in type expressions,
which is not necessarily normalizing in presence of recursive type definitions.
In other words, we must decide normalization of terms in the first-order
lambda-calculus with recursion. We provide an algorithm to detect
non-termination on-the-fly during reduction, with proofs of correctness and
completeness.
Our termination-monitoring algorithm turns out to be closely related to the
normalization strategy for macro expansion in the `cpp` preprocessor.Comment: Author version, to appear at POPL 202
3D Nanostructured Conjugated Polymers for Optical Applications
This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/adfm.201502392The self assembly of block-copolymers into the gyroid morphology was replicated into 3D nanostructured conjugated polymers. Voided styrenic gyroidal networks were used as scaffolds for the electrodeposition of two poly(3,4-ethylenedioxythiophene) (PEDOT) derivatives and poly(pyrrole) (PPy). The careful choice of solvents and electrolytes allowed the excellent replication of the initial self-assembled morphology into self-supporting gyroidal conjugated polymer networks. The nanostructured films were employed to fabricate electrochromic devices, exhibiting excellent colour contrast upon switching, with fast switching speeds. The versatility and reliability of this method was demonstrated by the creation of switchable Fresnel zone plates, with which the focussing of light can be switched on and off.We acknowledge the EPSRC EP/G060649/1 for funding. This study was supported by the Nokia Research Centre Cambridge
Alternating plane graphs
A plane graph is called alternating if all adjacent vertices have different degrees, and all neighboring faces as well. Alternating plane graphs were introduced in 2008. This paper presents the previous research on alternating plane graphs.
There are two smallest alternating plane graphs, having 17 vertices and 17 faces each. There is no alternating plane graph with 18 vertices, but alternating plane graphs exist for all cardinalities from 19 on. From a small set of initial building blocks, alternating plane graphs can be constructed for all large cardinalities. Many of the small alternating plane graphs have been found with extensive computer help.
Theoretical results on alternating plane graphs are included where all degrees have to be from the set {3,4,5}. In addition, several classes of “weak alternating plane graphs” (with vertices of degree 2) are presented
Déboîter les constructeurs
National audienceNous proposons une implémentation d'une nouvelle fonctionnalité pour OCaml, le déboîtement 1 de constructeurs. Elle permet d'éliminer certains constructeurs de la représentation dynamique des valeurs quand cela ne crée pas de confusion entre différentes valeurs au même type. Nous décrivons :-un cas d'usage sur les grands entiers où la fonctionnalité améliore les performances de code OCaml idiomatique,éliminant le besoin d'écrire du code non-sûr.-l'analyse statique nécessaire pour accepter ou rejeter le déboîtement d'un constructeur,-et l'impact sur la compilation du filtrage par motif. Pour notre analyse statique, nous devons normaliser certaines expressions de type, avec une relation de normalisation qui ne termine pas nécessairement en présence de types mutuellement récursifs ; nous décrivons une analyse dynamique de terminaison qui garantit la normalisation sans rejeter les définitions de types qui nous intéressent
PyTorch Geometric Temporal: Spatiotemporal Signal Processing with Neural Machine Learning Models
We present PyTorch Geometric Temporal a deep learning framework combining
state-of-the-art machine learning algorithms for neural spatiotemporal signal
processing. The main goal of the library is to make temporal geometric deep
learning available for researchers and machine learning practitioners in a
unified easy-to-use framework. PyTorch Geometric Temporal was created with
foundations on existing libraries in the PyTorch eco-system, streamlined neural
network layer definitions, temporal snapshot generators for batching, and
integrated benchmark datasets. These features are illustrated with a
tutorial-like case study. Experiments demonstrate the predictive performance of
the models implemented in the library on real world problems such as
epidemiological forecasting, ridehail demand prediction and web-traffic
management. Our sensitivity analysis of runtime shows that the framework can
potentially operate on web-scale datasets with rich temporal features and
spatial structure.Comment: Source code at:
https://github.com/benedekrozemberczki/pytorch_geometric_tempora
The Glass Transition Temperature of Water: A Simulation Study
We report a computer simulation study of the glass transition for water. To
mimic the difference between standard and hyperquenched glass, we generate
glassy configurations with different cooling rates and calculate the
dependence of the specific heat on heating. The absence of crystallization
phenomena allows us, for properly annealed samples, to detect in the specific
heat the simultaneous presence of a weak pre-peak (``shadow transition''), and
an intense glass transition peak at higher temperature.
We discuss the implications for the currently debated value of the glass
transition temperature of water. We also compare our simulation results with
the Tool-Narayanaswamy-Moynihan phenomenological model.Comment: submitted to Phys. Re
Monolithically Integratable Colliding Pulse Modelocked Laser Source for O-CDMA Photonic Chip Development
We demonstrate modelocking of a colliding-pulse mode-locked laser formed by 3-μm-deep etched-mirrors on an InP platform for integration with passive waveguide components. Timing jitter of 243 fs and pulse width of 10 ps were measured
Type of mRNA COVID-19 vaccine and immunomodulatory treatment influence humoral immunogenicity in patients with inflammatory rheumatic diseases
Patients with inflammatory rheumatic diseases (IRD) are at increased risk for worse COVID-19 outcomes. Identifying whether mRNA vaccines differ in immunogenicity and examining the effects of immunomodulatory treatments may support COVID-19 vaccination strategies. We aimed to conduct a long-term, model-based comparison of the humoral immunogenicity following BNT162b2 and mRNA-1273 vaccination in a cohort of IRD patients. Patients from the Swiss IRD cohort (SCQM), who assented to mRNA COVID-19 vaccination were recruited between 3/2021-9/2021. Blood samples at baseline, 4, 12, and 24 weeks post second vaccine dose were tested for anti-SARS-CoV-2 spike IgG (anti-S1). We examined differences in antibody levels depending on the vaccine and treatment at baseline while adjusting for age, disease, and past SARS-CoV-2 infection. 565 IRD patients provided eligible samples. Among monotherapies, rituximab, abatacept, JAKi, and TNFi had the highest odds of reduced anti-S1 responses compared to no medication. Patients on specific combination therapies showed significantly lower antibody responses than those on monotherapy. Irrespective of the disease, treatment, and past SARS-CoV-2 infection, the odds of higher antibody levels at 4, 12, and 24 weeks post second vaccine dose were, respectively, 3.4, 3.8, and 3.8 times higher with mRNA-1273 versus BNT162b2 (p < 0.0001). With every year of age, the odds ratio of higher peak humoral immunogenicity following mRNA-1273 versus BNT162b2 increased by 5% (p < 0.001), indicating a particular benefit for elderly patients. Our results suggest that in IRD patients, two-dose vaccination with mRNA-1273 versus BNT162b2 results in higher anti-S1 levels, even more so in elderly patients
Type of mRNA COVID-19 vaccine and immunomodulatory treatment influence humoral immunogenicity in patients with inflammatory rheumatic diseases.
Patients with inflammatory rheumatic diseases (IRD) are at increased risk for worse COVID-19 outcomes. Identifying whether mRNA vaccines differ in immunogenicity and examining the effects of immunomodulatory treatments may support COVID-19 vaccination strategies. We aimed to conduct a long-term, model-based comparison of the humoral immunogenicity following BNT162b2 and mRNA-1273 vaccination in a cohort of IRD patients. Patients from the Swiss IRD cohort (SCQM), who assented to mRNA COVID-19 vaccination were recruited between 3/2021-9/2021. Blood samples at baseline, 4, 12, and 24 weeks post second vaccine dose were tested for anti-SARS-CoV-2 spike IgG (anti-S1). We examined differences in antibody levels depending on the vaccine and treatment at baseline while adjusting for age, disease, and past SARS-CoV-2 infection. 565 IRD patients provided eligible samples. Among monotherapies, rituximab, abatacept, JAKi, and TNFi had the highest odds of reduced anti-S1 responses compared to no medication. Patients on specific combination therapies showed significantly lower antibody responses than those on monotherapy. Irrespective of the disease, treatment, and past SARS-CoV-2 infection, the odds of higher antibody levels at 4, 12, and 24 weeks post second vaccine dose were, respectively, 3.4, 3.8, and 3.8 times higher with mRNA-1273 versus BNT162b2 (p < 0.0001). With every year of age, the odds ratio of higher peak humoral immunogenicity following mRNA-1273 versus BNT162b2 increased by 5% (p < 0.001), indicating a particular benefit for elderly patients. Our results suggest that in IRD patients, two-dose vaccination with mRNA-1273 versus BNT162b2 results in higher anti-S1 levels, even more so in elderly patients
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