Multi-round Master-Worker Computing: a Repeated Game Approach

We consider a computing system where a master processor assigns tasks for execution to worker processors through the Internet. We model the workers decision of whether to comply (compute the task) or not (return a bogus result to save the computation cost) as a mixed extension of a strategic game among workers. That is, we assume that workers are rational in a game-theoretic sense, and that they randomize their strategic choice. Workers are assigned multiple tasks in subsequent rounds. We model the system as an infinitely repeated game of the mixed extension of the strategic game. In each round, the master decides stochastically whether to accept the answer of the majority or verify the answers received, at some cost. Incentives and/or penalties are applied to workers accordingly. Under the above framework, we study the conditions in which the master can reliably obtain tasks results, exploiting that the repeated games model captures the effect of long-term interaction. That is, workers take into account that their behavior in one computation will have an effect on the behavior of other workers in the future. Indeed, should a worker be found to deviate from some agreed strategic choice, the remaining workers would change their own strategy to penalize the deviator. Hence, being rational, workers do not deviate. We identify analytically the parameter conditions to induce a desired worker behavior, and we evaluate experi- mentally the mechanisms derived from such conditions. We also compare the performance of our mechanisms with a previously known multi-round mechanism based on reinforcement learning.Comment: 21 pages, 3 figure

Implementación de un prototipo experimental a pequeña escala que se encargue de automatizar el proceso de evolución de un libro en una biblioteca

El siguiente trabajo de grado, tiene como objetivo comprender la importancia del estudio de los tecnólogos en electricidad, solucionando las necesidades cotidianas de las personas, ya que el campo que les compete, está relacionado con casi todos los aspectos de la vida, y de las ocupaciones del ciudadano común; esto es lo que incita a la realización de este proyecto, el cual busca precisamente, beneficiar a los usuarios de una biblioteca, bien sea de la Universidad Tecnológica de Pereira, u otra entidad que posea una gran fuente bibliográfica; para tal fin de facilitarle este servicio a la comunidad. En este proyecto se plantea automatizar el proceso de devolución de libros; los beneficios que este proyecto traería a los usuarios del servicio, serían la rapidez y facilidad que se presenta al realizar el proceso, la seguridad que el libro ha sido registrado en la base de datos del sistema; y principalmente, ofrecer este servicio las 24 horas del día, ya que el sistema no necesita de un operador, esto debido a que es un procedimiento completamente automático, lo cual, conlleva a que el equipo funcione de forma indefinida, o hasta llegar al tope máximo de libros que puede almacenar, situación que se soluciona, luego de que un funcionario, retire los libros allí almacenados, lo que conlleva a que el equipo pueda estar en operación nuevamente. El presente trabajo de grado, se ocupa de realizar la primera fase de todo el proyecto en general, el cual fue dividido en dos fases, debido al gran alcance que éste posee, al gran espacio de tiempo que se necesita para realizarlo completamente, y principalmente los costos económicos que conlleva su desarrollo total. La primera fase, tiene como meta, desarrollar e implementar la parte referente al software y al hardware del sistema, para los cuales un tecnólogo eléctrico estaría en capacidad de diseñar e implementar, aplicando y profundizando sus conocimientos en diferentes áreas de la electricidad, como lo son el control de procesos industriales, instrumentación y medidas, física, máquinas eléctricas, entre otras. Los siguientes son los temas desarrollados en este proyecto: • Banda transportadora en doble sentido de giro. • Subsistema de sensado con diodos infrarrojos. • Subsistema de control con un microcontrolador. • Subsistema mecánico de almacenamiento de libros. • Subsistema de puerta automática. • Subsistema de simulación de un lector de código de barras

Monitorización de la Integridad Estructural de un Componente mediante Gemelos Digitales

RESUMEN: los Gemelos Digitales es una tecnología que consiste en la representación virtual de componentes o procesos reales para analizar su comportamiento y mejorar su eficacia. El objetivo de un Gemelo Digital es replicar los fenómenos físicos que se dan en su “gemelo real” mediante el uso de sensores. Por ello, el Gemelo Digital da una ventaja muy importante frente a sistemas convencionales por aportar información de la respuesta a tiempo real. La aparición de tecnologías como el “Big Data” o “La Nube” han facilitado la viabilidad empresarial e industrial de los Gemelos Digitales convirtiéndose en un campo de innovación para multitud de empresas y una herramienta estratégica para la prevención de fallos, optimización de procesos y planificación de la producción entre otros aspectos. La aplicación de Gemelos Digitales para la monitorización de la Integridad Estructural de componentes fundamentalmente pretende evitar fallos catastróficos, mejorar el conocimiento del comportamiento de las estructuras y aumentar la durabilidad de los componentes.ABSTRACT: Digital Twins is a technology consists of the virtual representation of real components or processes to analyze their behavior and improve their efficiency. The aim of Digital Twin is to replicate the physical phenomena which occur in its "real twin" through the use of sensors. For this reason, the Digital Twin gives a very important advantage over conventional systems by providing information on the response in real time. The beginning of technologies such as "Big Data" or "The Cloud" have facilitated the business and industrial viability of the Digital Twins, becoming a field of innovation for many companies and strategic tool for the prevention of failures, process optimization and production planning among other aspects. The application of Digital Twins for the monitoring of the Structural Integrity of components fundamentally aims to avoid catastrophic failures, improve the knowledge of the behavior of the structures and increase the durability of the components.Máster en Integridad y Durabilidad de Materiales, Componentes y Estructura

Flower visits of cockroaches (Insecta: Blattodea) in the Iberian Peninsula: Are they neglected pollinators?

Although several insect orders have been deeply studied in plant–animal interactions (e.g. pollination) cockroaches have traditionally been ignored in taxonomic and ecological studies. However, they could be playing a role in the reproduction of several plants. To date, 8 plant species use cockroaches as a pollination agent. In our study, we have reviewed 2865 records from citizen science platforms and our own data from the Iberian Peninsula to find flower visits made by cockroaches. We have detected 51 interaction records involving at least 8 different cockroach species and 35 plant species. Furthermore, nearly half of the detected cockroaches carried pollen on various parts of their bodies. These insects were found to mainly visit white, yellow and pink flowers from Apiaceae, Asteraceae and Cistaceae plant families (among others) mainly in late spring and early summer. However, for the confirmation of effective pollination, new studies must be carried out. Additionally, although the existence of pollination syndrome is far from being understood, we provide new insights that could help shed some light on this unknown relationship. Here we provide the first approximation of cockroach floral perception and we have detected that white flowers show the best fit and higher conspicousness to cockroach colour vision, as suggested for other neglected pollinator insects

QI in Resident Leadership Workshop

Background: Many residency programs provide some type of leadership training for chief residents. As these emerging leaders transition into their role, it is imperative to provide them with skills and knowledge to help them develop their leadership style. UTRGV’s department of Graduate Medical Education (GME) organized their first “Resident Leader Workshop” for all rising Chiefs and GME Resident Leadership Council (RLC) members. Using a pre and post survey, participants provided feedback on the effectiveness of knowledge and skills presented during the workshop. Methods: All residency and fellowship rising Chiefs and GME RLC members were invited. The workshop took place on May 25, 2022. It was a live event from 12:00-5:00pm at the School of Medicine Learning Center. The following topics were covered during the workshop: Middle Management Principles and Role Analysis, Well-being and Resilience, Personality Styles, Feedback, Conflict Management, and Leadership Tips. Participants completed pre and post surveys that were created on Qualtrics and delivered with QR codes. Time was allotted during the workshop to complete the surveys. Results analyzed from de-identified data from participants on their perception of effectiveness, strengths, and suggestions for improvement are presented below. Results: A total of 14 participants (5 females, 8 males, 1 gender variant/non-conforming), representing 11 residencies and 2 fellowship programs were present and completed the surveys. 4 participants had some type of previous training in leadership. In both the pre and post surveys, administrative was ranked as the top responsibility and clinical was ranked as the least responsibility of a leader. Participant responses indicate an increase in preparedness and confidence in starting their roles as leaders and managing conflict. They ranked personality styles, feedback, and conflict management as the “most beneficial” topics. Additional analysis will be completed from the data to better document their responses and to inform next steps in leadership development at UTRGV GME. Conclusions: The workshop helped the emergent leaders increase their confidence and preparedness in starting their new role as leaders and managing conflict. The workshop was effective, and the participants reported high satisfaction with the programming. Our goal is to continue providing leadership development

Diseño y desarrollo de un modelo experimental de competitividad para el sector universitarío: su aplicación a la carrera de “ingeniería en electrónica y telecomunicaciones” de la fiec

La Ley Orgánica de Educación Superior señala que las universidades, las escuelas politécnicas y los institutos superiores del país deben acreditarse de forma obligatoria según el modelo de autoevaluación del Consejo Nacional de Evaluación y Acreditación (CONEA); siendo la ESPOL una de las instituciones que ya está acreditada. Por tal motivo, el Plan estratégico de la ESPOL 2008-2012 (Borrador DOS), en el Objetivo 2 trata de la obtención y mantenimiento de la acreditación institucional y por carrera de grado y programas de postgrado a nivel nacional e internacional; estableciendo como tarea inmediata que “la ESPOL participará en el establecimiento de las características y estándares de calidad para la acreditación nacional de las carreras de Ingeniería en el marco del convenio de cooperación ESPOL-CONEA)”, y que “la acreditación de las carreras de Ingeniería es de prioridad institucional y como tal no se escatimarán recursos”. También, el objetivo 47 de este Borrador dos es “mantener y mejorar continuamente el sistema de gestión de calidad de la ESPOL de acuerdo a los requisitos de la norma ISO 9001:2000”, estableciendo como tarea inmediata: “integrar el Sistema de Gestión de Calidad (SGC) a los sistemas de evaluación con fines de acreditación nacional e internacional”, y como lineamiento básico que: “la ESPOL analizará la pertinencia de adoptar modelos internacionales de excelencia”. El presente trabajo busca cumplir estos dos objetivos mediante el diseño y desarrollo de un Modelo experimental que permita la acreditación de la carrera de Ingeniería en Electrónica y Telecomunicaciones, y al mismo tiempo cumpla con estándares de calidad internacionales (para este modelo se utilizarán los criterios del Modelo americano: Malcolm Baldrige), integrando en el sistema de calidad ISO 9001:2000 que la FIEC tiene certificado desde el 2 de Febrero del 2005

Impact of tillage and N fertilization rate on soil N2O emissions in irrigated maize in a Mediterranean agroecosystem

In irrigated Mediterranean conditions there is a lack of knowledge about the best combination of tillage and N fertilization practices to reduce soil nitrous oxide (N2O) emissions while maintaining maize productivity. The aim of this work was to investigate the effects of different soil management practices and synthetic N fertilization rates on soil N2O emissions and their relationship with maize grain yield to determine the best management system to reduce yield-scaled N2O emissions (YSNE) in a semiarid area recently converted to irrigation under Mediterranean conditions. A long-term tillage and N rate field experiment established in 1996 under barley (Hordeum vulgare L.) rainfed conditions, was converted to irrigated maize (Zea mays L.) in 2015. After the transformation to irrigation, the field experiment maintained the same tillage treatments and N fertilization rates. Three types of tillage (conventional tillage, CT; reduced tillage, RT; no-tillage, NT) and three mineral N fertilization rates (0, 200, 400 kg N ha−1) were compared during three years (2015-2017) in a randomized block design with three replications. Soil N2O emissions, water-filled pore space, soil temperature, mineral N content (as NH4+ and NO3−), denitrification potential and maize grain yield and above-ground N uptake were quantified. Moreover, the emission factor (EF) and YSNE were calculated. The results showed that the combination of NT and the highest rate of N fertilization led to greater N2O emissions. Furthermore, the lowest N2O fluxes were observed in CT when WFPS was below 40% and the highest N2O fluxes were seen in NT when WFPS was above 60% coinciding with the greatest denitrification potential. Cumulative N2O emissions in 2017 and 2015 followed the order 400 > 200 > 0 kg N ha−1, while in 2016, rate of 400 and 200 kg N ha−1 showed greater cumulative N2O emission compared to the control. Only RT showed differences between growing seasons on cumulative N2O emissions, with greater values in 2017 compared to 2015, and intermediate values in 2016. In all treatments, the N2O EF was much lower than the default IPCC emission factor (1%). NT and RT increased the grain production compared to CT which was affected by severe soil crusting causing water deficit. Likewise, N fertilizer treatments significantly affected the YSNE, increasing with increasing fertilizer N application rate in the first year of study. Our data show that the use of NT or RT does not lead to more yield-scaled N2O emissions than CT in Mediterranean agroecosystems recently converted to irrigation.This research work was financially supported by the Ministerio de Economía y Competitividad of Spain (project AGL2013-49062-C4-1-R; PhD fellowship BES‐2014‐070039). DPB received a Juan de la Cierva postdoctoral grant from the Ministerio de Economía y Competitividad of Spain (IJCI-2016-27784)

Is it feasible to reduce tillage and N use while improving maize yield in irrigated Mediterranean agroecosystems?

Mediterranean rainfed areas are transformed into irrigation to stabilize or increase crop yields. The gradual occupation of irrigation leads to an increase in nitrogen use and intensity of tillage. The aim of this work was to evaluate the combined impact of tillage systems and mineral N fertilization rates on maize grain yield, water and nitrogen use efficiencies (WUE and NUE) under Mediterranean irrigated conditions. The study was carried out in NE Spain during three maize growing seasons (i.e. years 2015, 2016 and 2017). A long-term (LTE) tillage and N rate field experiment established in 1996 under rainfed conditions was transformed into irrigation with maize (Zea mays L.) monoculture as cropping system in 2015. Three types of tillage (conventional tillage, CT; reduced tillage, RT; no-tillage, NT) and three mineral N fertilization rates (0, 200, 400 kg N ha-1) were compared in a randomized block design with three replications. In 2015, an adjacent experiment (short-term experiment, STE) with the same layout was set up in an area previously managed under long-term rainfed NT for the last 21 years. Soil water (SWC) and nitrate (SNC) content were quantified. Maize above ground biomass and N uptake, grain yield and yield components, grain N were measured at harvest. The WUE for above ground biomass and yield (WUEB and WUEY, respectively) and NUE, as well as other N-related indexes (nitrogen harvest index, NHI; apparent nitrogen recovery efficiency, NAR) were calculated. In the long-term tillage and N fertilization combination (LTE), the reduction of tillage (NT and RT) led to greater grain yield when applying 200 and 400 kg N ha-1 compared to the use of the same rates under CT. Differently, in the sort-term experiment with preceding NT (STE), tillage systems did not influence grain yields, while N application led to greater yields than the control (0 kg N ha-1). In both situations (LTE and STE), NT and RT enhanced SWC before planting leading to greater crop growth compared to CT. The lack of available water under CT caused lower maize above-ground biomass, yield, and yield components in LTE and, therefore, lower WUEB and WUEY. In LTE, the use of long-term CT led to a significant accumulation of nitrate compared to NT. Differently, in the STE, SNC did not show differences between tillage systems. In the LTE, water and N were used more efficiently to produce above-ground biomass and grain yield in RT and NT. Our study shows that in Mediterranean agroecosystems transformed into irrigation the use of NT and RT with medium rates of N leads to greater maize yield, WUE and NUE than the traditional management based on CT with high rates of mineral N. In rainfed areas with long-term history of no-till, this soil management system can be successfully maintained if transformed into irrigation.We would like to thank the field and laboratory technicians Javier Bareche, Carlos Cortés, Barbara Jelcic and Silvia Martí. This research work was financially supported by the Ministerio de Economía y Competitividad of Spain (project AGL2013-49062-C4-1-R; PhD fellowship BES‐2014‐070039). DPB received a Juan de la Cierva postdoctoral grant from the Ministerio de Economía y Competitividad of Spain (IJCI-2016-27784)

Tillage and nitrogen fertilization in irrigated maize: key practices to reduce soil CO2 and CH4 emissions

In newly irrigated Mediterranean agroecosystems, the combined effect of tillage and N fertilization on soilcarbon dioxide (CO2) and methane (CH4)fluxes is at present poorly understood. The goal of this study was toquantify both soil CO2and CH4emissions as well as crop performance under different tillage systems and Nfertilization rates during three maize (Zea maysL.) growing seasons (2015-2017) in a semiarid area converted toirrigated. Three types of tillage (conventional tillage, CT, reduced tillage, RT, and no-tillage, NT) and threemineral N fertilization rates (0, 200, and 400 kg N ha−1) were compared in a randomized block design withthree replications. Weekly soil CO2and CH4emissions, soil temperature and gravimetric moisture were mea-sured. Moreover, maize above-ground biomass, grain yield, and above-ground C-inputs were quantified. Carbondioxide emissions ranged from 173 to 4378 mg CO2-C m-2d-1. No-tillage showed a greater mean soil CO2fluxthan CT when applying the highest rate of N (400 kg N ha-1). Although some emissions of CH4were observed, alltreatments acted as net CH4sinks during most of the experimental period. A linear multiple relationship betweensoil CO2fluxes and soil gravimetric moisture (0-5 cm depth) and temperature (10 cm depth) were found. In the2015 growing season, greater cumulative CO2emissions were found under NT and RT compared with CT, whilein 2016 N T showed the highest values compared to CT with intermediate values in RT. Differently, in 2017 nodifferences between tillage systems were found. When applying N fertilizer, NT and RT increased maize grainproduction and above-ground C-inputs compared to CT, since a severe soil crusting occurred in this last, whichcaused crop water deficit. The results suggest that tillage intensity and N fertilization rate reduction can increasemaize biomass production and yield which leads to greater C-input that returns to the soil.We would like to thank the field and laboratory technicians Carlos Cortés, Barbara Jelcic, Javier Bareche and Silvia Martí. This research work was financially supported by the Ministerio de Economía y Competitividad of Spain (project AGL2013-49062-C4-1-R; PhD fellowship BES‐2014‐070039). DPB received a Juan de la Cierva postdoctoral grant from the Ministerio de Economía y Competitividad of Spain (IJCI-2016-27784)