6,527 research outputs found
A hybrid genetic approach to solve real make-to-order job shop scheduling problems
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro TecnologicoProcedimentos de busca local (ex. busca tabu) e algoritmos genĂ©ticos tĂȘm apresentado excelentes resultados em problemas clĂĄssicos de programação da produção em ambientes job shop. No entanto, estas abordagens apresentam pobres habilidades de modelamento e poucas aplicaçÔes com restriçÔes de ambientes reais de produção tĂȘm sido publicadas. AlĂ©m disto, os espaços de busca considerados nestas aplicaçÔes sĂŁo nomlalmente incompletos e as restriçÔes reais sĂŁo poucas e dependentes do problema em questĂŁo. Este trabalho apresenta uma abordagem genĂ©tica hĂbrida para resolver problemas de programação em ambientes job shop com grande nĂșmero de restriçÔes reais, tais como produtos com vĂĄrios nĂveis de submontagem, planos de processamento altemativos para componentes e recursos alternativos para operaçÔes, exigĂȘncia de vĂĄrios recursos para executar uma operação (ex., mĂĄquina, ferramentas, operadores), calendĂĄrios para todos os recursos, sobreposição de operaçÔes, restriçÔes de disponibilidade de matĂ©ria-prima e componentes comprados de terceiros, e tempo de setup dependente da sequĂȘncia de operaçÔes. A abordagem tambĂ©m considera funçÔes de avaliação multiobjetivas. O sistema usa algoritmos modificados de geração de programação, que incorporam vĂĄrias heurĂsticas de apoio Ă decisĂŁo, para obter um conjunto de soluçÔes iniciais. Cada solução inicial Ă© melhorada por um algoritmo de subida de encosta. EntĂŁo, um algoritmo genĂ©tico hĂbrido com procedimentos de busca local Ă© aplicado ao conjunto inicial de soluçÔes localmente Ăłtimas. Ao utilizar tĂ©cnicas de programação de alta perfomlance (heurĂsticas construtivas, procedimentos de busca local e algoritmos genĂ©ticos) em problemas reais de programação da produção, este trabalho reduziu o abismo existente entre a teoria e a prĂĄtica da programação da produção
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New kid on the block: lipid droplets in the nucleus.
The regulation of lipid homeostasis is essential for normal cell physiology, and its disruption can lead to disease. Lipid droplets (LDs) are ubiquitous organelles dedicated to storing nonpolar lipids that are used for metabolic energy production or membrane biogenesis. LDs normally emerge from, and associate with, the endoplasmic reticulum and interact with other cytoplasmic organelles to deliver the stored lipids. Recently, LDs were found to reside also at the inner side of the nuclear envelope and inside the nucleus in yeast and mammalian cells. This unexpected finding raises fundamental questions about the nature of the inner nuclear membrane, its connection with the endoplasmic reticulum and the pathways of LD formation. In this viewpoint, we will highlight recent developments relating to these questions and discuss possible roles of LDs in nuclear physiology
Exploiting the FLOSS paradigm in collaborative e-learning : application to e-government
Modern societies face high demands for skilled professionals, able to successfully design, deploy and utilize complex Information Technology (IT) âenabled socio-technical systems at ever- increasing levels of reliability and security. Contrary to traditional education practices, the high-level training required to fulfill this demand should rely on the principle that the learners are themselves responsible for their learning process, that they have control over this process, and that the process aims at developing cross-disciplinary and problem-driven competences, not only at acquiring content knowledge. However, such training requires the presence of a highly interactive, problem-oriented environment for technology-supported learning (or e-learning). This poster presents a doctoral research project, which aims at designing, validating and monitoring a collaborative e-learning environment based on the principles of Free/Libre Open Source Software (FLOSS). In order to validate its outcomes, the project will rely on two real-life professional training programs: in Software Engineering for software managers and in e-Government for public managers. The poster presents the objectives, research methodology and expected results from this project.(undefined
A pilot project on non-conventional learning
This poster presents a pilot project on non-conventional learning strategies based on studentsâ active participation in real-life FLOSS projects. The aim of the project is to validate the hypothesis that the peer-production model, which underlies most FLOSS projects, can enhance the learning-teaching process based on extensive and systematic collaborative practices.(undefined
A preliminary analysis of learning awareness in FLOSS projects
It can be argued that participating in free/libre open source software (FLOSS) projects can have a positive effect in the contributor's learning process. The need to interact with other contributors, to read other people's code, write documentation, or use different tools, can motivate and implicitly foster learning. In order to validate this statement we design an appropriate questionnaire asking FLOSS contributors about their experience in FLOSS
projects. In this paper, we illustrate how this questionnaire was designed and what we expect to learn from the answers. We conclude the paper with a preview of the results from three cases studies.(undefined
Configurations of web services
The quest for sound foundations for the orchestration of web services is still open. To a great extent its relevance comes from the possibility of defining formal semantics for new language standards (like BPEL4WS or WS-CDL) in this emerging and challenging technology. As a step in that direction, this paper resorts to a notion of configuration, developed by the authors in the context of a Reo-like exogenous coordination model for software components, to formally express service orchestration. The latter is regarded as involving both the architectural assembly of independent services and the description of their interactions.Fundação para a CiĂȘncia e a Tecnologia (FCT) - PURe Project, contract POSI/ICHS/44304/2002
Differentiable positive definite kernels on two-point homogeneous spaces
In this work we study continuous kernels on compact two-point homogeneous spaces which are positive definite and zonal (isotropic). Such kernels were characterized by R. Gangolli some forty years ago and are very useful for solving scattered data interpolation problems on the spaces. In the case the space is the d-dimensional unit sphere, J. Ziegel showed in 2013 that the radial part of a continuous positive definite and zonal kernel is continuously differentiable up to order â(dâ1)/2â in the interior of its domain. The main issue here is to obtain a similar result for all the other compact two-point homogeneous spaces.CNPq (grant 141908/2015-7)FAPESP (grant 2014/00277-5
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