Classificação multicritério de peças de reposição

Pós-graduação em Engenharia Mecânica - FEG

El color en las aceitunas negras naturales de mesa : nueva técnica de mensura digitalizada para optimizar el método de oscurecimiento natural

Se aplicó un nuevo método para la evaluación objetiva del color en aceitunas de mesa, basado en el análisis de la intensidad de reflexión de cada uno de los colores primarios que componen la luz blanca (rojo, verde y azul), según las longitudes de onda del Sistema RGB. Se trabajó con programas informáticos para el análisis de imágenes digitales color tipo BMP de 24 bits. Este trabajo proporciona mayor información sobre el pardeamiento de las aceitunas naturales en salmuera, lo que sería muy útil para incrementar la efectividad del proceso. El método propuesto es rápido y no destructivo, prometiendo ser muy práctico ya que permite que una misma muestra pueda ser evaluada en el tiempo. Se investigaron los cambios de color en aceitunas elaboradas naturalmente, con diferentes grados de madurez (pintas, rojas y negras) y a diferentes valores de pH (3,6 - 4,0 - 4,5), expuestas al aire durante períodos crecientes de tiempo. Se cuantificó el grado de oscurecimiento a través de Índices de Intensidad de Reflexión. La evolución del índice de reflexión en función del tiempo generó una curva polinomial de 4° grado que reveló el comportamiento sigmoidal del fenómeno de pardeamiento enzimático, con la máxima correlación a las 8 horas de aireación. Esta función permitiría predecir el fenómeno de pardeamiento en las aceitunas negras y representa una medición objetiva del grado relativo de pardeamiento. La evolución del color rojo (λ = 700,0 nm) exhibió la mayor correlación con el proceso de pardeamiento. Las aceitunas rojas naturales a pH 4,5 presentaron óptimo pardeamiento. El espectro de reflexión para el color azul (λ = 435,8 nm) se sugiere como medida de la actividad de la enzima PPO (polifenoloxidasa).

Experiences in the assessment of the requirement management process

The focus of this paper is to outline the practical experiences and the lessons learned derived from the assessment of the requirements management process in two industrial case studies. Furthermore this paper explains the main structure of an alternative assessment approach that has been used in the appraisal of the two case studies. The assessment approach helped us to know the current state of the organizational requirement management process. We have to point out that these practical experiences and the lessons learned can be helpful to reduce risks and costs of the on-site assessment process.

Determining practices achievement in the requirement management process using a two-stage questionnaire

This paper aims to obtain a baseline snapshot of the requirement management process using a two-stage questionnaire to identify both performed and non-performed CMMI practices. The questionnaire proposed in this paper may help with the assessment of the requirement management process, provide useful information related to the current state of the process, and indicate those practices that require immediate attention with the aim of begin a Software Process Improvement program.

Marco de trabajo para adaptar las metodologías ágiles e implantarlas a nivel organizacional

Contexto: La adopción y adaptación de las metodologías ágiles ha sido objeto de estudio en la comunidad y diversas aproximaciones han sido propuestas como solución al problema. La mayoría de las organizaciones comienzan introduciendo prácticas ágiles de manera progresiva, las cuales, junto a las buenas prácticas ya existentes, conforman una nueva metodología ágil adaptada. El problema más importante con el que se enfrentan las organizaciones al adaptar una metodología ágil, son las necesidades específicas del contexto de cada proyecto, porque a pesar de haber definido la adaptación de la metodología en base a las buenas prácticas y procesos existentes en la organización, las condiciones particulares del proyecto y del equipo que lo va a desarrollar, exigen adaptaciones específicas. Otro aspecto importante a resolver es el poder implantar esta adopción y adaptación en toda la organización. Las metodologías ágiles no incluyen actividades que asistan a las organizaciones a solucionar este problema, porque su esfuerzo lo centran en el equipo y el proyecto. Objetivo: El objetivo principal de este trabajo de investigación consiste en “definir un marco de trabajo de adaptación de metodologías ágiles orientado a contextos que permita su implantación en toda la organización a través de ciclos de mejora basados en la reutilización de experiencias adquiridas”. Este marco de trabajo permitirá organizar, gestionar y validar la adaptación de las metodologías ágiles, desplegando en toda la organización las experiencias adquiridas, incorporando pequeñas mejoras en el proceso, y facilitando su reutilización. Todo esto, con el apoyo de la alta dirección. Método: Este trabajo se inició con una investigación exploratoria acompañada de una revisión sistemática para conocer el estado del arte del objeto de estudio, detectando las principales carencias y necesidades de resolución, a partir de las cuales, se delimitó el alcance del problema. Posteriormente, se definieron las hipótesis de investigación y se planteó una solución al problema a través de la definición del marco de trabajo, cuyos resultados fueron evaluados y validados a través de la realización de un caso de estudio. Finalmente, se obtuvieron las conclusiones y se establecieron las líneas futuras de investigación. Resolución: El marco de trabajo presenta una alternativa de adaptación de las metodologías ágiles orientada a contextos, y facilita su implantación en toda la organización. El marco de trabajo idéntica los contextos en los que se desarrollan los proyectos y analiza la causa de los problemas que afectan a la consecución de los objetivos de negocio en cada contexto. Posteriormente, identifica las acciones de adaptación requeridas para reducir o eliminar estas causas y las incorpora en la definición de la metodología ágil, creando de esta manera, una metodología adaptada para cada contexto manteniendo un nivel de agilidad aceptable. Cuando se inicia un nuevo proyecto, se identifica su contexto y se aplica la metodología ágil adaptada definida para dicho contexto. Al final de cada iteración, se analizan las medidas obtenidas y se las compara con la media aplicando una técnica para la evaluación de la consecución de los objetivos. En base a esta comparativa, y a la experiencia adquirida por el equipo, se realizan ajustes en las acciones de adaptación para intentar conseguir una mejora en la siguiente iteración. Una vez finalizado el proyecto, se conoce el impacto de los resultados conseguidos y se puede determinar si se ha alcanzado una mejora en el contexto del proyecto. De ser así, la metodología adaptada es almacenada en un repositorio de experiencias para poder ser reutilizada por otros equipos de desarrollo de la organización. Resultados: El trabajo de investigación fue evaluado y validado satisfactoriamente a través de su experimentación en un caso de estudio, aprobando las hipótesis establecidas. Los aportes y principales resultados de esta investigación son: Definición de un marco de trabajo integral de adaptación de metodologías ágiles, con capacidad de facilitar su implantación en toda la organización. Procedimiento para identificar contextos o escenarios de adaptación. Procedimiento para definir unidades de adaptación a partir de los inhibidores de los objetivos de negocio de la organización. Técnica para analizar la consecución de objetivos en propuestas de mejora de procesos. Conclusiones: Son tres las ventajas principales que han quedado evidenciadas durante la realización del trabajo de investigación: El marco de trabajo proporciona un mecanismo capaz de optimizar el rendimiento de la metodología ágil adaptada al orientar el proceso a las necesidades específicas del contexto del proyecto. El marco de trabajo permite conservar el conocimiento empírico adquirido por el equipo de desarrollo al registrarlo como experiencia adquirida para la organización. El marco de trabajo optimiza y reduce los tiempos del proceso de implantación de la metodología ágil adaptada en otros equipos de la organización. ABSTRACT Context: The adoption and tailoring of agile methods has been studied in the community and various approaches have been proposed as a solution. Most organizations start introducing agile practices gradually, which ones, together with existing good practices, make a new agile method tailored. When an organization starts to adapt an agile method, the context-specific needs of each project are the main trouble, because even though the agile method tailored has been defined based on best practices and processes in the organization, the specific conditions of the project and its team, require specific adaptations. Another important aspect to be solved is to implement this adoption and adaptation throughout all the organization. Agile methods do not include specific activities for helping organizations to solve this problem, because their effort is focused on the team and the project. Objective: The main objective of this research is to “define a tailoring framework for agile methods oriented to contexts that allows its deployment throughout all the organization using improvement cycles based on the reuse of lessons learned”. This framework will allow organize, manage and validate the tailoring of agile methods, adding small improvements in the process, and facilitating reuse. All this, with the support of senior management. Method: This work began with an exploratory investigation accompanied by a systematic review to determine the state of the art about the object of study, after major gaps and needs resolution were identified, and the scope of the problem was delimited. Subsequently, the research hypotheses were defined and the framework was developed for solving the research problem. The results were evaluated and validated through a case study. Finally, conclusions were drawn and future research were established. Resolution The framework presents an alternative for tailoring agile methodologies and facilitates its implementation throughout all the organization. The framework identifies the contexts or scenarios in which software development projects are developed and analyses the causes of the problems affecting the achievement of business goals in each context. Then the adaptation actions required to reduce or eliminate these causes are defined and incorporated into the definition of agile method. Thus, a method tailored for each context is created. When a new project is started, the context in which it will be developed is identified and the tailored agile method to that context is applied. At the end of each iteration of the project, the measurements obtained are analysed and compared with the historical average of context to analyse the improvement in business goals. Based on this comparison, and the experience gained by the project team, adjustments are made in adaptation actions to try to achieve an improvement in the next iteration. Once the project is completed, the impact of the achieved results are known and it can determine if it has reached an improvement in the context of the project. If so, the tailored agile method is stored in a repository of experiences to be reused by other development teams in the organization. Results The goal of this research was successfully evaluated and validated through experimentation in a case study, so the research hypotheses were approved. The contributions and main results of this research are: A framework for tailoring agile methods, that allows its deployment throughout all the organization. A procedure for identifying adaptation scenarios or contexts. A procedure for defining adaptation units from inhibitors of the business goals of the organization. A technique for analysing the achievement of goals in process improvement proposals. Conclusions: There are three main advantages that have been highlighted during the research: The framework provides a mechanism to optimize the performance of agile methods because it guides the process based on the specific needs of the project context. The framework preserves the empirical knowledge acquired by the development team because it registers this empirical knowledge as experience for the organization. The framework streamlines and shortens the process of deploying the tailored agile method to other teams in your organization.

Estudo de práticas adotadas por empresas que utilizam a Produção Enxuta em paralelo ao Seis Sigma no processo de melhoria

As empresas estão utilizando diversos processos de melhoria para adequarem seus negócios às necessidades dos clientes, à maior concorrência, a uma necessidade de flexibilização e de redução dos custos de seus processos de manufatura. O seis sigma e a produção enxuta são dois processos utilizados por empresas no Brasile no mundo. Atualmente a integração destes processos é um desafio para essas empresas, que buscam uma maneira mais eficiente de reduzir seus desperdícios e se adaptarem às necessidades de seus mercados consumidores. Surge, assim, o Lean Sigma aplicado nas empresas de diversas formas. O objetivo deste trabalho é estruturar, por meio de dois estudos de caso, como as empresas estão utilizando o seis Sigma e a Produção Enxuta em seus processos de melhoria. Verificou-se que existem diferentes formas de utilizar os processos em paralelo: na primeira empresa o processo iniciou em conjunto e depois foi separado em dois processos paralelos de melhoria. A segunda empresa foi ao contrário, começando de forma paralela, desagregada, e posteriormente se unindo em um único processo de melhoria, denominado Lean Sigma. O trabalho apresenta uma sistematização do processo de melhoria de duas empresas, dividido em Visão Geral e Objetivos, Estrutura Organizacional e Métodos de Melhoria. Foram verificadas as formas gerais de utilização dos processos de melhoria e que uma abordagem integrada, que contemple as peculiaridades de cada processo, se demonstra como uma melhor opção para um processo de melhoria que utiliza a Produção Enxuta e o Seis Sigma paralelamente. A pesquisa traz, também, como resultado, uma proposta de sistematização do Lean Sigma, considerando o conhecimento adquirido nos estudos de caso e na literatura consultada.

Targetless image-based method for measuring displacements and strains on concrete surfaces with a consumer camera

Measurement of concrete strain through non-invasive methods is of great importance in civil engineering and structural analysis. Traditional methods use laser speckle and high quality cameras that may result too expensive for many applications. Here we present a method for measuring concrete deformations with a standard reflex camera and image processing for tracking objects in the concretes surface. Two different approaches are presented here. In the first one, on-purpose objects are drawn on the surface, while on the second one we track small defects on the surface due to air bubbles in the hardening process. The method has been tested on a concrete sample under several loading/unloading cycles. A stop-motion sequence of the process has been captured and analyzed. Results have been successfully compared with the values given by a strain gauge. Accuracy of our methods in tracking objects is below 8 μm, in the order of more expensive commercial devices.

Phase progression throughout the therapeutic process : longitudinal case studies

Tese de doutoramento, Psicologia (Psicologia Clínica), Universidade de Lisboa, Faculdade de Psicologia, 2016

A method for automatically eliciting node weights in a hierarchical knowledge-based structure for reasoning with uncertainty

Hierarchical knowledge structures are frequently used within clinical decision support systems as part of the model for generating intelligent advice. The nodes in the hierarchy inevitably have varying influence on the decisionmaking processes, which needs to be reflected by parameters. If the model has been elicited from human experts, it is not feasible to ask them to estimate the parameters because there will be so many in even moderately-sized structures. This paper describes how the parameters could be obtained from data instead, using only a small number of cases. The original method [1] is applied to a particular web-based clinical decision support system called GRiST, which uses its hierarchical knowledge to quantify the risks associated with mental-health problems. The knowledge was elicited from multidisciplinary mental-health practitioners but the tree has several thousand nodes, all requiring an estimation of their relative influence on the assessment process. The method described in the paper shows how they can be obtained from about 200 cases instead. It greatly reduces the experts’ elicitation tasks and has the potential for being generalised to similar knowledge-engineering domains where relative weightings of node siblings are part of the parameter space.

Manufacturing process challenges when machining superalloys

The implementation of advanced manufacturing systems with high process capability is an essential requirement for the high value manufacturing industries. To ensure high process capability, industry needs to deal with the requirement for tight tolerances and the unavoidable variations in materials, and manufacturing and inspection processes. In the case of machining superalloys, such variations result in the need to change the machine parameters for producing different batches of materials from different suppliers. This is required in order to get the process under control and reduce waste and defects, leading to better competitiveness. This papers discuss the variability in materials and the corresponding process requirements when machining superalloys, and highlights the impact of metrology in achieving manufacturing process improvement.

Vocabulary and language model adaptation using information retrieval

International audience

Autoavaliação da governança de TI em uma autarquia federal com base na gestão de riscos

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2016.

The complexity in the implementation process of empowerment-based chronic kidney care: a case study

Background: This study is part of an interactive improvement intervention aimed to facilitate empowerment-based chronic kidney care using data from persons with CKD and their family members. There are many challenges to implementing empowerment-based care, and it is therefore necessary to study the implementation process. The aim of this study was to generate knowledge regarding the implementation process of an improvement intervention of empowerment for those who require chronic kidney care. Methods: A prospective single qualitative case study was chosen to follow the process of the implementation over a two year period. Twelve health care professionals were selected based on their various role(s) in the implementation of the improvement intervention. Data collection comprised of digitally recorded project group meetings, field notes of the meetings, and individual interviews before and after the improvement project. These multiple data were analyzed using qualitative latent content analysis. Results: Two facilitator themes emerged: Moving spirit and Encouragement. The healthcare professionals described a willingness to individualize care and to increase their professional development in the field of chronic kidney care. The implementation process was strongly reinforced by both the researchers working interactively with the staff, and the project group. One theme emerged as a barrier: the Limitations of the organization. Changes in the organization hindered the implementation of the intervention throughout the study period, and the lack of interplay in the organization most impeded the process. Conclusions: The findings indicated the complexity of maintaining a sustainable and lasting implementation over a period of two years. Implementing empowerment-based care was found to be facilitated by the cooperation between all involved healthcare professionals. Furthermore, long-term improvement interventions need strong encouragement from all levels of the organization to maintain engagement, even when it is initiated by the health care professionals themselves.