Automated Validation of Compensable SLAs

A Service Level Agreement (SLA) regulates the provisioning of a service by defining a set of guarantees. Each guarantee sets a Service Level Objective (SLO) on some service metrics, and optionally a compensation that is applied when the SLO is unfulfilled or overfulfilled. Currently, there are software tools and research proposals that use the information about compensations to automate and optimise certain parts of the service management. However, they assume that compensations are well defined, which is too optimistic in some circumstances and can lead to undesirable situations. In this article we discuss about the notion of validity of guarantees with a compensation, which we refer to as compensable guarantees (CG). We describe an abstract model of CGs and we provide a technique that leverages constraint satisfaction problem solvers to automatically validate them. We also present a materialisation of the model of CGs in iAgree, a language to specify SLAs and a tooling support that implements our whole approach. An assessment over 319 CGs taken from 24 real-world SLAs suggests that the expressiveness and effectiveness of our proposal can pave the way for using CGs in a safer and more reliable way.Ministerio de Economía y Competitividad BELI (TIN2015-70560-R)Ministerio de Ciencia, Innovación y Universidades TIN2016-81978-REDTJunta de Andalucía P12--TIC--186

First steps: study protocol for a randomized controlled trial of the effectiveness of the Group Family Nurse Partnership (gFNP) program compared to routine care in improving outcomes for high-risk mothers and their children and preventing abuse.

BACKGROUND: Evidence from the USA suggests that the home-based Family Nurse Partnership program (FNP), extending from early pregnancy until infants are 24 months, can reduce the risk of child abuse and neglect throughout childhood. FNP is now widely available in the UK. A new variant, Group Family Nurse Partnership (gFNP) offers similar content but in a group context and for a shorter time, until infants are 12 months old. Each group comprises 8 to 12 women with similar expected delivery dates and their partners. Its implementation has been established but there is no evidence of its effectiveness. METHODS/DESIGN: The study comprises a multi-site randomized controlled trial designed to identify the benefits of gFNP compared to standard care. Participants (not eligible for FNP) must be either aged < 20 years at their last menstrual period (LMP) with one or more previous live births, or aged 20 to 24 at LMP with low educational qualifications and no previous live births. 'Low educational qualifications' is defined as not having both Maths and English Language GCSE at grade C or higher or, if they have both, no more than four in total at grade C or higher. Exclusions are: under 20 years and previously received home-based FNP and, in either age group, severe psychotic mental illness or not able to communicate in English. Consenting women are randomly allocated (minimized by site and maternal age group) when between 10 and 16 weeks pregnant to either to the 44 session gFNP program or to standard care after the collection of baseline information. Researchers are blind to group assignment.The primary outcomes at 12 months are child abuse potential based on the revised Adult-Adolescent Parenting Inventory and parent/infant interaction coded using the CARE Index based on a video-taped interaction. Secondary outcomes are maternal depression, parenting stress, health related quality of life, social support, and use of services. DISCUSSION: This is the first study of the effectiveness of gFNP in the UK. Results should inform decision-making about its delivery alongside universal services, potentially enabling a wider range of families to benefit from the FNP curriculum and approach to supporting parenting. TRIAL REGISTRATION: ISRCTN78814904

Financial considerations in the conduct of multi-centre randomised controlled trials: evidence from a qualitative study.

National Coordinating Centre for Research Methodology; Medical Research Council, UK Department of Health; Chief Scientist OfficeNot peer reviewedPublisher PD

SLA management of non-computational services.

El incremento en el uso de arquitecturas orientadas a servicios en los últimos 15 años ha propiciado la propuesta de numerosas técnicas para automatizar y dar soporte al uso de dichos servicios. Un elemento fundamental en la provisión de servicios es el Acuerdo de Nivel de Servicio (ANS), donde se formalizan los requisitos y garantías de consumidor y proveedor respecto del rendimiento del servicio. Las propuestas para servicios computacionales, además de proveer modelos formales para describirlos, proponen la automatización de las diferentes etapas del ciclo de vida del ANS, tales como la negociación de las garantías para crear un ANS, el despliegue de servicios basados en el ANS, o la gestión de los recursos para cumplir las garantías provistas en el mismo. Sin embargo, en los servicios tradicionales, no computacionales, es decir, los servicios que no son ejecutados por recursos computacionales, tales como los servicios de logística o de desarrollo de software, la gestión de sus ANSs todavía se realiza por medios ad-hoc. Así, las soluciones existentes no pueden ser reutilizadas por diferentes servicios. Y, en la mayoría de los casos, esta gestión se hace de manera manual (p.e. revisión de los objetivos acordados en los ANSs de servicios de transporte), por lo que la evaluación de estos ANSs es susceptible a errores y se suele retrasar respecto a la ejecución del servicio (p.e. cuando el ANS ha finalizado), por lo que no se pueden tomar acciones preventivas para evitar el incumplimiento del ANS o estas acciones no son rentables. En estos escenarios, aparecen, además, acuerdos marco para un periodo largo (p.e. 1 aõ), durante el cual pueden aparecen ANSs relacionados con éste para un periodo más específico y el análisis de la coherencia entre acuerdos marco y acuerdos específicos es complicada de hacer durante la ejecución del servicio. En esta tesis, nos proponemos automatizar parcialmente la gestión de los ANSs de servicios no computacionales. Así, por un lado, proponemos que los modelos para servicios computacionales se extiendan a servicios no computacionales, de manera que permitan describir la operativa del servicio y sus garantías. Y, por otro lado, basado en estos modelos, proporcionamos el diseño de operaciones para gestionar el ciclo de vida de los ANS. Concretamente, estas operaciones se basan en las fases de despligue y evaluación del ANS. De forma específica, esta tesis propone tres contribuciones principales. Primero, (A) extender iAgree para dar soporte al modelado de los ANS de servicios no computacionales. Segundo, (B) dar soporte al ciclo de vida de dichos ANS mediante la formalización de las operaciones citadas (configuración del servicio basada en el ANS y monitorización del mismo) y, a partir de estas operaciones, implementamos una arquitectura de referencia para estas operaciones. Y, por último, (C) proveemos el modelado de la relación entre acuerdos marco y específicos que relacione sus términos junto con la formalización de las operaciones para el análisis que aparecen entre ellos. Otros aspectos del ciclo de vida del servicio y del ANS, como la gestión de los recursos para mejorar el rendimiento del servicio o el uso de técnicas (como machine learning) para la predicción del cumplimiento de los ANSs están fuera del contexto de esta tesis, pero se plantean como futuras líneas de extensión. Este trabajo se ha basado en ANSs reales de diferentes dominios, tales como servicios de Transporte y Logística, proveedores de Cloud or outsourcing de desarrollo TIC, que se han utilizado para validar las propuestas. Además, las contribuciones presentadas se han aplicado en el contexto de proyectos reales de soporte de sistemas TIC.The rise of computational services in the last 15 years brought the proposal of a number of techniques to automate and support their enactment. One key element in services is the Service Level Agreement (SLA), where the requirements of service customer are matched with the performance levels from the service provider to define service level guarantees and related responsibilities. The proposals from computational domains are oriented to automate the different stages in the SLA Lifecycle, such as the negotiation of terms which will form the SLA, the deployment of services based on the SLA artifact or the management of computational resources to accomplish SLA goals on runtime. However, traditional non-computational services, that is, services which are not performed by computational resources, such as logistics or software development services, are still supported by ad-hoc mechanisms. Therefore, the existing solutions for the management of their SLAs cannot be reused for other services. This management is usually manually performed (e.g.: reviewing of the goals of an SLA in transport service), so their evaluation is error-prone and delayed regarding the service execution (e.g.: when the SLA is finished), so preemptive actions to avoid SLA violations cannot be taken or/and are expensive to perform. Furthermore, these SLAs are sometimes described on a long term basis (frame agreements), and related SLAs can appear for a shorter term (specific agreements) and the analysis of the validity among them is complex to perform on runtime. In this dissertation, we aim at partially automate the management of SLAs in noncomputational services. On the one hand, we suggest that existing models for computational services can be extended to non computational services and enable the description of the service operative and their guarantees. And, on the other hand, we provide a design for operations to partially support the SLA Lifecycle, based on the previous models. Specifically, these operations are mainly focused on the deployment and fulfillment stages of the SLA. Therefore, the contributions of this dissertation are three. First, (A) providing a model to describe Service Level Agreements of non computational services, as an extension of iAgree, an existing model for SLAs of computational services. Second side, (B) supporting the SLA Lifecycle with the design of the aforementioned operations (service configuration based on SLA and monitoring of SLA) and implementing a reference architecture for such operations. And, lastly, (C) providing a model for frame and specific agreements which relates their terms and formalises the analysis operations among them. Other related operations of the service lifecycle as the management of resources to improve service performance or the use of novel techniques (such as machine learning) to predict the SLA accomplishment are out of the scope of this thesis but planned as future line of extension. The current dissertation has been based on real SLAs from different domains, such as Transport & Logistics, public Cloud providers or IT Maintenance outsourcing, which have been used to validate the proposal. And, furthermore, the contributions have been applied in the context of real IT Maintenance outsourcing projects

Designing role-based view for object-relational databases

In a federated database system, a view mechanism is crucial since it is used to define exportable subsets of data ; to perform a virtual restructuring d ataset; and to construct the integrated schema. The view service in federated databa se systems must be capable of retaining as much semantic information as possible. The object-oriented ( 0 - 0 ) model was considered the suitable canonical data model since it meets the original criteria for canonical model selection. However, with the emergence of stronger object-relational (0 -R ) model, the re is a clear argument for using an 0 - R canonical model in the federation. Hence, research should now focus on th e development of semantically powerful view mechanism for th e newer model. Meanwhile, the availability of real 0 -R technologies offers researchers the opportunity to develop different forms of view mechanisms. The concept of roles has been widely studied in 0 - 0 modelling and development. The role model represents some characteristics that the traditional 0-0 model lacked, such as object migration, multiple occurrences and context-dependent access. While many forms of 0-0 views were designed for the 0-0 canonical model, one option was to extend the 0-0 model to incorporate a role model. In a role model, the real entity is modelled in the form of a role rather than an object. An object represents the permanent properties of an entity is a root object; and an object represents the temporary properties of an entity is a role object. The contribution of this research is to design a view system that employees the concept of roles for the 0 -R canonical model in a federated database system. In this thesis, an examination of the current 0 -R metamodel is provided first in order to provide an environment for recognising the roleview metadata and measuring the view performance; then a Roleview Definition Language (RDL) is introduced, along with the semantics for defining virtual classes and generating virtua l extents; finally, a working prototype is provided to prove th e role-based view system is implementable and the syntax is semantically correct

Essays on asset allocation and diversification

Inflatierisico heeft meetbare impact op omvang optimale aandelenportefeuille De invloed van inflatieschommelingen op aandelenkoersen is statistisch lastig te meten, maar inflatierisico heeft wel degelijk gevolgen voor de omvang van de optimale aandelenportefeuille. Dat concludeert Tomek Katzur in zijn promotieonderzoek. Katzur richtte zich op vraagstukken over vermogensbeheer in opkomende economieën. In het recente verleden zijn pensioen- en beleggingsfondsen in deze economieën sterk in omvang toegenomen. Het uiteindelijke succes van deze fondsen hangt af van de vraag of zij in staat blijken een stabiele reële inkomensstroom aan hun deelnemers te leveren. Met dat perspectief onderzocht Katzur, aan de hand van empirische casestudies, de verhouding tussen risico en rendement van beleggingen op de langere termijn. Hij bestudeerde onder meer het nieuwe nationale pensioenstelsel van India. Katzur constateert dat Indiase staatsobligaties, ondanks hun relatief hoge rendement, weinig aantrekkelijk zijn voor risico-averse beleggers. Om deze groep bij het pensioenstelsel te betrekken, is het stabiliseren van de inflatie een eerste vereiste. Katzur wierp ook nieuw licht op eerdere studies over de voorspelbaarheid van aandelenrendementen in opkomende markten, waaruit bleek dat beleggingen in deze aandelen op termijn minder riskant zouden zijn. Toepassing van nieuwe statistische technieken, die rekening houden met onzekerheid over de geschatte parameters, toont echter aan dat dit niet het geval is

Annual Report of the University, 1972-1973, Volumes 1-3

At the varsity level, our teams have competed in the following sports: football, basketball, track, cross country, baseball, tennis, wrestling, swimming, golf, gymnastics and skiing. Junior varsity teams played regular schedules in football and basketball. A total of 167 athletes received major letter awards; 21 freshmen athletes were awarded numerals in basketball and football making a grand total of 188

Classroom climate and teacher questioning strategies : relationship to student cognitive development

The purpose of this research was to determine if classroom climate and teacher questioning strategies have an influence on level of student cognitive development. The three null hypotheses stated that no statistically significant differences existed between classroom climate and level of student cognitive development; between teacher questioning strategies and level of student cognitive development; and between the combination of classroom climate and teacher questioning strategies and level of student cognitive development. Thirty students, randomly selected from eight seventh and eighth grade language arts classrooms, comprised the sample. The Classroom Climate and Questioning Strategies observation instrument was used to cluster the teachers on the basis of observed frequency of climate and questioning practices. A student cognitive test was administered individually to the 15 students in the experimental group and the 15 students in the control group as a pre- and post-treatment measure of level of student cognitive development