Ray Tracing acceleration through a custom scheduling policy to take advantage of the cache affinity in a Linux-based Special-Purpose Operating System

Proyecto de Graduación (Maestría en Electrónica) Instituto Tecnológico de Costa Rica, Escuela de Ingeniería Electrónica, 2021Esta investigación explora el beneficio de diseñar una política de calendarizacion personalizada que reduzca el tiempo de de ejecución de cargas computacionalmente intensivas. Cargas computacionalmente intensivas tales como ray tracing, son sensibles al cambio de contexto producido por el calendarizador. La política de calendarización propuesta asigna afinidad de cache fuerte para reducir el cambio de contexto al permitir que cada hilo tenga asignado un único núcleo para su ejecución. Utilizando un sistema operativo de propósito especifico, hipotéticamente, el sistema tendrá un mayor rendimiento al combinarlo con la política de calendarización personalizada. El algoritmo de ray tracing fue seleccionado como carga computacionalmente intensiva para comparar su rendimiento en un sistema operativo de propósito especifico contra un sistema operativo de propósito general con su configuración por defecto. Comparado a la referencia, ANOVA factorial confirmo un 19% de reducción en el tiempo de sintetizado promedio al usar la política de calendarización personalizada en un sistema operativo de propósito especifico.The present research explores the benefit of designing a custom scheduling policy to reduce the execution time for computationally intensive workloads. Computationally intensive workloads, such as, ray tracing, are sensible to the context switching produced by the scheduler. The proposed custom scheduling policy assigns hard cache affinity to reduce the context switching by allowing each thread to use only one core during the process execution. Utilizing a special-purpose operating system will hypothetically boost the reduced execution time by integrating the custom scheduling policy. Ray tracing algorithm was selected as the computationally intensive workload to compare its performance in the special-purpose operating system with the custom scheduling policy against a generalpurpose operating system with the default configuration. Compared to the baseline, the factorial ANOVA test confirmed an average 19% reduction of the rendering time using the custom scheduling policy in a special-purpose operating system

Calendario agrícola y deserción escolar en los espacios rurales del Perú

Tiene como objetivo identificar si el calendario agrícola tiene un efecto negativo sobre la deserción escolar. Particularmente se postula que un calendario agrícola muy estacional generará una demanda de mano de obra muy fuerte en ciertos meses del año, generando que los niños y adolescentes se dediquen a labores agrícolas, aumentando así la probabilidad de deserción. Para ello se estima modelos logit, diferenciando a alumnos matriculados, no matriculados y aquellos matriculados pero que no asisten al colegio. Los resultados apoyan débilmente la hipótesis planteada pues un calendario agrícola estacional tiene un efecto negativo, pero no significativo sobre la probabilidad de estar matriculado y asistir al colegio y, un efecto negativo y significativo sobre la probabilidad de matricula

Reliability Prediction of Acrylonitrile O-Ring for Nuclear Power Applications Based on Shore Hardness Measurements

none4siThe degradation of polymeric components is of considerable interest to the nuclear industry and its regulatory bodies. The objective of this work was the development of a methodology to determine the useful life—based on the storage temperature—of acrylonitrile O-rings used as mechanical sealing elements to prevent leakages in nuclear equipment. To this aim, a reliability-based approach that allows prediction of the use-suitability of different storage scenarios (that involve different storage times and temperatures) considering the further required in-service performance, is presented. Thus, experimental measurements of Shore A hardness have been correlated with storage variables (temperature and storage time). The storage (and its associated hardening) was proved to have a direct effect on in-service durability, reducing this by up to 60.40%. Based on this model, the in-service performance was predicted; after the first three years of operation the increase in probability of failure (POF) was practically insignificant. Nevertheless, from this point on, and especially, from 5 years of operation, the POF increased from 10% to 20% at approximately 6 years (for new and stored). From the study, it was verified that for any of the analysis scenarios, the limit established criterion was above that of the storage time premise considered in usual nuclear industry practices. The novelty of this work is that from a non-destructive test, like a Shore A hardness measurement, the useful life and reliability of O-rings can be estimated and be, accordingly, a decision tool that allows for improvement in the management of maintenance of safety-related equipment. Finally, it was proved that the storage strategies of our nuclear power plants are successful, perfectly meeting the expectations of suitability and functionality of the components when they are installed after storage.openAlvaro Rodríguez-Prieto; Ernesto Primera; Mariaenrica Frigione; Ana María CamachoRodríguez-Prieto, Alvaro; Primera, Ernesto; Frigione, Mariaenrica; María Camacho, An

Analysis of the Technological Evolution of Materials Requirements Included in Reactor Pressure Vessel Manufacturing Codes

The growth of green energy technologies within the frame of the 7th Sustainable Development Goal (SDG) along with the concern about climatic changes make nuclear energy an attractive choice for many countries to ensure energy security and sustainable development as well as to actively address environmental issues. Unlike nuclear equipment (immovable goods), which are often well-catalogued and analyzed, the design and manufacturing codes and their standardized materials specifications can be considered movable and intangible goods that have not been thoroughly studied based on a detailed evaluation of the scientific and technical literature on the reactor pressure vessel (RPV) materials behavior. The aim of this work is the analysis of historical advances in materials properties research and associated standardized design codes requirements. The analysis, based on the consolidated U.S. Nuclear Regulatory Commission (NRC) Regulatory Guide (RG) 1.99 Rev.2 model, enables determination of the best materials options, corresponding to some of the most widely used material specifications such as WWER 15Kh2MFAA (used from the 1970s and 1980s; already in operation), ASME SA-533 Grade B Cl.1 (used in pressurized water reactor-PWR 2nd–4th; already in operation), DIN 20MnMoNi55 and DIN 22NiMoCr37 (used in PWR 2nd–4th) as well as ASTM A-336 Grade F22V (current designs). Consequently, in view of the results obtained, it can be concluded that the best options correspond to recently developed or well-established specifications used in the design of pressurized water reactors. These assessments endorse the fact that nuclear technology is continually improving, with safety being its fundamental pillar. In the future, further research related to the technical heritage from the evolution of materials requirements for other clean and sustainable power generation technologies will be performed

PART: Pre-trained Authorship Representation Transformer

Authors writing documents imprint identifying information within their texts: vocabulary, registry, punctuation, misspellings, or even emoji usage. Finding these details is very relevant to profile authors, relating back to their gender, occupation, age, and so on. But most importantly, repeating writing patterns can help attributing authorship to a text. Previous works use hand-crafted features or classification tasks to train their authorship models, leading to poor performance on out-of-domain authors. A better approach to this task is to learn stylometric representations, but this by itself is an open research challenge. In this paper, we propose PART: a contrastively trained model fit to learn \textbf{authorship embeddings} instead of semantics. By comparing pairs of documents written by the same author, we are able to determine the proprietary of a text by evaluating the cosine similarity of the evaluated documents, a zero-shot generalization to authorship identification. To this end, a pre-trained Transformer with an LSTM head is trained with the contrastive training method. We train our model on a diverse set of authors, from literature, anonymous blog posters and corporate emails; a heterogeneous set with distinct and identifiable writing styles. The model is evaluated on these datasets, achieving zero-shot 72.39\% and 86.73\% accuracy and top-5 accuracy respectively on the joint evaluation dataset when determining authorship from a set of 250 different authors. We qualitatively assess the representations with different data visualizations on the available datasets, profiling features such as book types, gender, age, or occupation of the author

Exercise motivational regulations and exercise addiction: The mediating role of passion

Background and aims The study explored the mediating role of forms of passion in the relationship between motivational regulations in exercise and exercise addiction (EA). Methods A total of 485 university students (368 males and 117 females; Mage = 20.43, SD = 3.21) completed a questionnaire measuring the frequency and intensity of exercise, motivational regulations in exercise, passion for exercise, and EA. Controlling the effects of age, frequency, and intensity of practice, the relationships between the study variables were examined though a path analysis. Results Both self-determined and non-self-determined forms of motivation showed positive association with EA. The forms of motivation with greatest predictive power for EA were introjected and integrated regulations. Both forms of motivation had positive direct and indirect effects through obsessive passion (OP) on EA; however, integrated regulation also showed negative indirect effects through harmonious passion on EA. Conclusions Both forms of passion and, especially, OP, seem to affect how motivational regulations are associated with EA. These findings clarify the association found in previous studies between self-determined forms of motivation and EA

Gravity or turbulence? -III. Evidence of pure thermal Jeans fragmentation at ~0.1 pc scale

We combine previously published interferometric and single-dish data of relatively nearby massive dense cores that are actively forming stars to test whether their `fragmentation level' is controlled by turbulent or thermal support. We find no clear correlation between the fragmentation level and velocity dispersion, nor between the observed number of fragments and the number of fragments expected when the gravitationally unstable mass is calculated including various prescriptions for `turbulent support'. On the other hand, the best correlation is found for the case of pure thermal Jeans fragmentation, for which we infer a core formation efficiency around 13 per cent, consistent with previous works. We conclude that the dominant factor determining the fragmentation level of star-forming massive dense cores at 0.1 pc scale seems to be thermal Jeans fragmentation.Comment: accepted in MNRA

Utilização de lítio durante a gravidez : um relato de caso usando análise de decisão clínica

Editorial95-98There is great potential for the application of decisionmaking analysis in Psychiatry; especially in situations where the risk of continuing treatment is considerable. While the implementation of decision analysis can be time consuming