Economic regulation for multi tenant infrastructures

Large scale computing infrastructures need scalable and effi cient resource allocation mechanisms to ful l the requirements of its participants and applications while the whole system is regulated to work e ciently. Computational markets provide e fficient allocation mechanisms that aggregate information from multiple sources in large, dynamic and complex systems where there is not a single source with complete information. They have been proven to be successful in matching resource demand and resource supply in the presence of sel sh multi-objective and utility-optimizing users and sel sh pro t-optimizing providers. However, global infrastructure metrics which may not directly affect participants of the computational market still need to be addressed -a.k.a. economic externalities like load balancing or energy-efficiency. In this thesis, we point out the need to address these economic externalities, and we design and evaluate appropriate regulation mechanisms from di erent perspectives on top of existing economic models, to incorporate a wider range of objective metrics not considered otherwise. Our main contributions in this thesis are threefold; fi rst, we propose a taxation mechanism that addresses the resource congestion problem e ffectively improving the balance of load among resources when correlated economic preferences are present; second, we propose a game theoretic model with complete information to derive an algorithm to aid resource providers to scale up and down resource supply so energy-related costs can be reduced; and third, we relax our previous assumptions about complete information on the resource provider side and design an incentive-compatible mechanism to encourage users to truthfully report their resource requirements effectively assisting providers to make energy-eff cient allocations while providing a dynamic allocation mechanism to users.Les infraestructures computacionals de gran escala necessiten mecanismes d’assignació de recursos escalables i eficients per complir amb els requisits computacionals de tots els seus participants, assegurant-se de que el sistema és regulat apropiadament per a que funcioni de manera efectiva. Els mercats computacionals són mecanismes d’assignació de recursos eficients que incorporen informació de diferents fonts considerant sistemes de gran escala, complexos i dinàmics on no existeix una única font que proveeixi informació completa de l'estat del sistema. Aquests mercats computacionals han demostrat ser exitosos per acomodar la demanda de recursos computacionals amb la seva oferta quan els seus participants son considerats estratègics des del punt de vist de teoria de jocs. Tot i això existeixen mètriques a nivell global sobre la infraestructura que no tenen per que influenciar els usuaris a priori de manera directa. Així doncs, aquestes externalitats econòmiques com poden ser el balanceig de càrrega o la eficiència energètica, conformen una línia d’investigació que cal explorar. En aquesta tesi, presentem i descrivim la problemàtica derivada d'aquestes externalitats econòmiques. Un cop establert el marc d’actuació, dissenyem i avaluem mecanismes de regulació apropiats basats en models econòmics existents per resoldre aquesta problemàtica des de diferents punts de vista per incorporar un ventall més ampli de mètriques objectiu que no havien estat considerades fins al moment. Les nostres contribucions principals tenen tres vessants: en primer lloc, proposem un mecanisme de regulació de tipus impositiu que tracta de mitigar l’aparició de recursos sobre-explotats que, efectivament, millora el balanceig de la càrrega de treball entre els recursos disponibles; en segon lloc, proposem un model teòric basat en teoria de jocs amb informació o completa que permet derivar un algorisme que facilita la tasca dels proveïdors de recursos per modi car a l'alça o a la baixa l'oferta de recursos per tal de reduir els costos relacionats amb el consum energètic; i en tercer lloc, relaxem la nostra assumpció prèvia sobre l’existència d’informació complerta per part del proveïdor de recursos i dissenyem un mecanisme basat en incentius per fomentar que els usuaris facin pública de manera verídica i explícita els seus requeriments computacionals, ajudant d'aquesta manera als proveïdors de recursos a fer assignacions eficients des del punt de vista energètic a la vegada que oferim un mecanisme l’assignació de recursos dinàmica als usuari

Currency management system: a distributed banking service for the grid

Market based resource allocation mechanisms require mechanisms to regulate and manage the usage of traded resources. One mechanism to control this is the definition of some kind of currency. Within this context, we have implemented a first prototype of our Currency Management System, which stands for a decentralized and scalable banking service for the Grid. Basically, our system stores user accounts within a DHT and its basic operation is the transferFunds which, as its name suggests, transfers virtual currency from an account to one another

Moving towards preventive maintenance in wind turbine structural control and health monitoring

This work has been partially funded by the Spanish Agencia Estatal de Investigación (AEI)—Ministerio de Economía, Industria y Competitividad (MINECO), and the Fondo Europeo de Desarrollo Regional (FEDER) through the research projects PID2021-122132OB-C21 and TED2021- 129512B-I00; and by the Generalitat de Catalunya through the research projects 2021-SGR-01044.Peer ReviewedPostprint (published version

Erosion caused by propeller jets in a low energy harbour basin

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Journal of Hydraulic Research on January, 2017, available online at: http://www.tandfonline.com/10.1080/00221686.2016.1252801Field data of a harbour basin are compared with analytical formulations for predicting maximum scouring depth due to propeller jets. Spatial data analysis of seven-year biannual bathymetries quantifies the evolution of the scouring hole along with the sedimentation process within a harbour basin. The maximum scouring depth is found to be of the order of the propeller diameter with a maximum scouring rate within the first six months of docking manoeuvring. Three of the analysed expressions yielded realistic results while observed discrepancies between the theoretical predictions and field data are related to scaling factors. The outcomes of this analysis can be extrapolated to other harbours to improve their management. The obtained results highlight the importance of field data in developing combined physical and numerical models.Peer ReviewedPostprint (author's final draft

Evaluation of Risk Determinants Related to Ethyl Alcohol and Tobacco Consumption in the Adolescent Population

At present, the consumption of ethyl alcohol and tobacco in the adolescent population has generated a significant impact worldwide, being a topic of great relevance in today's society. Adolescents who are involved in the consumption of these substances put their health and safety at risk, motivated by various factors such as the search for social acceptance, the easy availability of these substances, among others. The objective of this research was to identify the risk factors associated with the consumption of ethyl alcohol and tobacco in adolescents. A quantitative and descriptive approach was used, using surveys as an instrument to understand the causes that led adolescents to consume these substances. The results revealed that 45% of adolescents admitted having started using with the purpose of fitting into a social group, while 30% attributed it to family problems. In addition, 15% mentioned that they wanted to feel better emotionally, and 10% experimented with these substances. It is important to highlight that adolescents start consuming ethyl alcohol and tobacco in order to adapt to their social environment, face family problems, seek emotional relief in situations that they cannot resolve on their own, or simply out of curiosity and experimentation

Alcohol and Tobacco Consumption Among Adolescents: A Descriptive Quantitative Approach

Aim: This research aimed to find the factors influencing alcohol and tobacco consumption among adolescents. A descriptive quantitative approach was employed, using questionnaires to gather information on the reasons adolescents engage in alcohol and tobacco use. Material and method: The findings revealed that most of the respondents-initiated substance use to reach social acceptance, followed by reasons related to family problems, and after to feel better or out of curiosity/experimentation. These findings show that adolescents turn to these substances as a means of seeking social acceptance, escaping family problems, and coping with challenges. Statistics and Result: The study underscores the importance of addressing these risk factors in preventive interventions targeting adolescents, as well as the need to provide them with tools to effectively cope with emotional and familial issues

Online structural damage classification methodology for offshore wind turbine foundations using data stream analysis

Structural health monitoring (SHM) of wind turbines is crucial to improve maintenance and extend their lifespan. This study develops an online data analysis methodology using data stream analysis to classify damage in the links of an offshore wind turbine foundation. The methodology is validated using a laboratory-scaled jacket-type wind turbine foundation structure. 2460 measurements of the healthy structure were acquired, and a 5mm crack was applied to four different links to determine the four unhealthy classes. 820 measurements were taken for each of the unhealthy structures, resulting in a dataset with 5740 instances. As this is an imbalanced multiclass classification problem, a random sampler approach was used to treat the data. The only data obtained was from eight triaxial accelerometers distributed throughout the structure. Three different tree-based stream data classifiers were compared: Hoeffding Tree classifier, Extremely Fast Decision Tree classifier, and Hoeffding Adaptive Tree classifier. Each classification model underwent a tuning parameter procedure, and high values of the receiving operating characteristic area under the curve (ROC AUC) metric were achieved as a result. It is important to note that stream learning differs from batch learning.Peer ReviewedPostprint (published version

New electronic tongue sensor array system for accurate liquor beverage classification

The use of sensors in different applications to improve the monitoring of a process and its variables is required as it enables information to be obtained directly from the process by ensuring its quality. This is now possible because of the advances in the fabrication of sensors and the development of equipment with a high processing capability. These elements enable the development of portable smart systems that can be used directly in the monitoring of the process and the testing of variables, which, in some cases, must evaluated by laboratory tests to ensure high-accuracy measurement results. One of these processes is taste recognition and, in general, the classification of liquids, where electronic tongues have presented some advantages compared with traditional monitoring because of the time reduction for the analysis, the possibility of online monitoring, and the use of strategies of artificial intelligence for the analysis of the data. However, although some methods and strategies have been developed, it is necessary to continue in the development of strategies that enable the results in the analysis of the data from electrochemical sensors to be improved. In this way, this paper explores the application of an electronic tongue system in the classification of liquor beverages, which was directly applied to an alcoholic beverage found in specific regions of Colombia. The system considers the use of eight commercial sensors and a data acquisition system with a machine-learning-based methodology developed for this aim. Results show the advantages of the system and its accuracy in the analysis and classification of this kind of alcoholic beverage.This research was funded by the Department of Science, Technology and Innovation of Colombia, grant 799, and Universidad Nacional de Colombia, grant 57399.Peer ReviewedPostprint (published version

Hamilton–Jacobi theory and integrability for autonomous and non-autonomous contact systems

In this paper, we study the integrability of contact Hamiltonian systems, both time-dependent and independent. In order to do so, we construct a Hamilton–Jacobi theory for these systems following two approaches, obtaining two different Hamilton–Jacobi equations. Compared to conservative Hamiltonian systems, contact Hamiltonian systems depend of one additional parameter. The fact of obtaining two equations reflects whether we are looking for solutions depending on this additional parameter or not. In order to illustrate the theory developed in this paper, we study three examples: the free particle with a linear external force, the freely falling particle with linear dissipation and the damped and forced harmonic oscillator

Output Power and Gain Monitoring in RF CMOS Class A Power Amplifiers by Thermal Imaging

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The viability of using off-chip single-shot imaging techniques for local thermal testing in integrated Radio Frequency (RF) power amplifiers (PA’s) is analyzed. With this approach, the frequency response of the output power and power gain of a Class A RF PA is measured, also deriving information about the intrinsic operation of its transistors. To carry out this case study, the PA is heterodynally driven, and its electrical behavior is down converted into a lower frequency thermal field acquirable with an InfraRed Lock-In Thermography (IR-LIT) system. After discussing the theory, the feasibility of the proposed approach is demonstrated and assessed with thermal sensors monolithically integrated in the PA. As crucial advantages to RF-testing, this local approach is noninvasive and demands less complex instrumentation than the mainstream commercially available solutions.Peer ReviewedPostprint (author's final draft