975 resultados para Assembly job shop scheduling
Resumo:
This article examines the job prospects of displaced industrial workers in Switzerland. Based on a survey of 1,203 workers who were dismissed after their manufacturing plants closed down, we analyse the determinants of re-employment, the sector of re-employment and the change in wages. Two years after displacement, a majority of workers were back in employment: 69% were re-employed, 17% un-employed and 11% retired. Amongst re-employed workers, two thirds found a job in manufacturing and one third in services. Contrary to a common belief, low-end services are not the collecting vessel of redundant industrial workers. Displaced workers aged 55 and older seem particularly vulnerable after a plant closes down: over 30% were long-term unemployed, and those older workers who found a new job suffered disproportionate wage losses. Advanced age-and not low education-appears as the primary handicap after mass redundancy.
Resumo:
Se estudia la programación de la producción en sistemas flow shop híbrido con tiempos depreparación dependientes de la secuencia de piezas a fabricar. Las piezas pueden pertenecer adiferentes familias y las máquinas requerirán un tiempo de preparación cada vez que se debacambiar de familia. Se han desarrollado procedimientos heurísticos para el caso monocriterio enel que el objetivo buscado en la programación de la producción es la minimización del retrasomedio, equivalente a minimizar la suma de retrasos de las piezas, y para el caso bicriterio en elque se tendrá en cuenta tanto la minimización de una función objetivo formada por la sumaponderada del retraso medio más la suma de los tiempos medios de proceso. Además se hanadaptado los métodos implementados para trabajar bajo la restricción nowait.
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The General Assembly Line Balancing Problem with Setups (GALBPS) was recently defined in the literature. It adds sequence-dependent setup time considerations to the classical Simple Assembly Line Balancing Problem (SALBP) as follows: whenever a task is assigned next to another at the same workstation, a setup time must be added to compute the global workstation time, thereby providing the task sequence inside each workstation. This paper proposes over 50 priority-rule-based heuristic procedures to solve GALBPS, many of which are an improvement upon heuristic procedures published to date.
Resumo:
Tutkimuksen päätavoite on arvioida, ovatko neljä ohjelmistovaihtoehtoa riittäviä tuotannon aikataulutuksen työkaluja ja mikä työkaluista sopii toimeksiantajayritykselle. Alatavoitteena on kuvata tuotannon aikataulutuksen nyky- ja tahtotila prosessimallinnuksen avulla, selvittää työkalun käyttäjätarpeet ja määritellä priorisoidut valintakriteerit työkalulle.Tutkimuksen teoriaosuudessa tutkitaan tuotannon aikataulutuksen logiikkaa ja haasteita. Työssä tarkastellaan aikataulutusohjelmiston valintaa rinnakkain prosessinmallinnuksen kanssa. Aikataulutusohjelmistovaihtoehdot ja metodit käyttäjätarpeiden selvittämiseksi käydään läpi. Empiriaosuudessa selvitetään tutkimuksen suhde toimeksiantajayrityksen strategiaan. Käyttäjätarpeet selvitetään haastattelujen avulla jaanalysoidaan QFD matriisin avulla. Toimeksiantajayrityksen tuotannon aikataulutuksen nyky- ja tahtotilaprosessit mallinnetaan, jotta ohjelmistojen sopivuutta, aikataulutusprosessia tukevana työkaluna voidaan arvioida.Tutkimustuloksena ovatpriorisoidut valintakriteerit aikataulutustyökalulle eli käyttäjätarpeista johdetut tärkeimmät toiminnalliset ominaisuudet, järjestelmätoimittaja-arvio sekä suositukset jatkotoimenpiteistä ja lisätutkimuksesta.
Resumo:
Tämän työn tarkoituksena on käytännöllisen suositusjärjestelmäratkaisun kehittäminen verkkokauppaympäristöön olemassaolevaa teoriatietoa käyttäen. Työn ensimmäisessä osiossa tarkastellaan ensin tapoja lähdetiedon keräämiseksi järjestelmää varten. Tämän jälkeen käydään läpi eri menetelmiä suosituksen toteuttamiseksi. Lisäksi tutustutaan yleisiin ongelmiin eri menetelmien kanssa. Seuraavaksi tutkitaan miten järjestelmän käyttämään suositustietoa voidaan ryhmitellä. Tämänjälkeen arvioidaan esitettyjä menetelmiä yleisesti tunnettujen kriteerien perusteella. Suositusjärjestelmän toteutustyö on kuvattuna työn toisessa osiossa. Toteutettu ohjelmisto on asennettu kahteen erilliseen toimintaympäristöön.
Resumo:
This paper analyses the effect of job accessibility by public and private transport on labour market outcomes in the metropolitan area of Barcelona. Beyond employment, we consider the effect of job accessibility on job-education mismatch, which represents a relevant aspect of job quality. We adopt a recursive system of equations that models car availability, employment and mismatch. Public transport accessibility appears as an exogenous variable in the three equations. Even though it may reflect endogenous residential sorting, falsification proofs suggest that the estimated effect of public transport accessibility is not entirely driven by the endogenous nature of residential decisions.
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L"edició del 2009 de la trobada de l"IFLA s"ha celebrat a Milà. La maquinària de l"organització va funcionar amb precisió per a aquest esdeveniment. Després d"anys de regularitat en les trobades per tot el món, l"IFLA funciona com un autòmat, una d"aquestes màquines perfectes, tant que podria continuar uncionant en les formes amb exemplar artifici. És un trobada singular, que aplega, a la vegada, la reunió de l"organització, un congrés mundial i una fira comercial; tot això amanit amb una ciutat diferent cada any i un finançament que depèn de la bona marxa de tot l"esdeveniment. En certa mesura, l"IFLA és un aparador de la professió, al qual assisteixen bibliotecaris de tot el món i de centenars d"institucions, amb tot el que suposa d"artificiositat en la representació d"entitats i promoció; un espai de reflexió, amb ponències i debats de molt variat interès que poden trobar-se, generalment, en altres esdeveniments; i una posada a punt dels treballs de tots els comitès, que tenen un complex desenvolupament previ i una àrdua tasca desenvolupada amb generositat per tots els participants.
Resumo:
HLA-DR antigens are polymorphic cell surface glycoproteins, expressed primarily in B lymphocytes and macrophages, which are thought to play an important role in the immune response. Two polypeptide chains, alpha and beta, are associated at the cell surface, and a third chain associates with alpha and beta intracellularly. RNA isolated from the human B-cell line Raji was injected in Xenopus laevis oocytes. Immunoprecipitates of translation products with several monoclonal antibodies revealed the presence of HLA-DR antigens similar to those synthesized in Raji cells. One monoclonal antibody was able to bind the beta chain after dissociation of the three polypeptide chains with detergent. The presence of all three chains was confirmed by two-dimensional gel electrophoresis. The glycosylation pattern of the three chains was identical to that observed in vivo, as evidenced in studies using tunicamycin, an inhibitor of N-linked glycosylation. The presence of alpha chains assembled with beta chains in equimolar ratio was further demonstrated by amino-terminal sequencing. An RNA fraction enriched for the three mRNAs, encoding alpha, beta, and intracellular chains, was isolated. This translation-assembly system and the availability of monoclonal antibodies make it possible to assay for mRNA encoding specific molecules among the multiple human Ia-like antigens.
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The object of this project is to schedule a ctitious European basketball competition with many teams situated a long distances. The schedule must be fair, feasible and economical, which means that the total distance trav- eled by every team must be the minimal possible. First, we de ne the sport competition terminology and study di erent competition systems, focusing on the NBA and the Euroleague systems. Then we de ne concepts of graph theory and spherical distance that will be needed. Next we propose a com- petition system, explaining where will be allocated the teams and how will be the scheduling. Then there is a description of the programs that have been implemented, and, nally, the complete schedule is displayed, and some possible improvements are mentioned.
Resumo:
In order to establish guidelines for irrigation water management of banana cv. Pacovan (AAB group, Prata sub-group) in Petrolina County, northeastern Brazil, the root distribution and activity were measured on an irrigated plantation, in a medium texture soil, with plants spaced in a 3 x 3 m grid. Root distribution was evaluated by the soil profile method aided by digital image analysis, while root activity was indirectly determined by the changing of soil water content and by the direction of soil water flux. Data were collected since planting in January 1999 to the 3rd harvest in September 2001. Effective rooting depth increased from 0.4 m at 91 days after planting (dap), to 0.6 m at 370, 510, and 903 dap, while water absorption by roots was predominantly in the top 0,6 m.
Resumo:
The water consumption and the crop coefficient of the banana cv. Pacovan were estimated in Petrolina County, northeastern Brazil, in order to establish guidelines to irrigation water management. Evaluations were carried out since planting in January 1999 to the 3rd harvest in September 2001 on a microsprinkler irrigated orchard, with plants spaced in a 3 x 3 m grid. Average daily water consumption was 3.9, 4.0, and 3.3 mm in the 1st, 2nd and 3rd growing seasons, respectively. Crop coefficient values increased from 0.7 (vegetative growth) to 1.1 (flowering). Even with high soil water availability, transpiration was reduced due to high evaporative demand.
Resumo:
The resource utilization level in open laboratories of several universities has been shown to be very low. Our aim is to take advantage of those idle resources for parallel computation without disturbing the local load. In order to provide a system that lets us execute parallel applications in such a non-dedicated cluster, we use an integral scheduling system that considers both Space and Time sharing concerns. For dealing with the Time Sharing (TS) aspect, we use a technique based on the communication-driven coscheduling principle. This kind of TS system has some implications on the Space Sharing (SS) system, that force us to modify the way job scheduling is traditionally done. In this paper, we analyze the relation between the TS and the SS systems in a non-dedicated cluster. As a consequence of this analysis, we propose a new technique, termed 3DBackfilling. This proposal implements the well known SS technique of backfilling, but applied to an environment with a MultiProgramming Level (MPL) of the parallel applications that is greater than one. Besides, 3DBackfilling considers the requirements of the local workload running on each node. Our proposal was evaluated in a PVM/MPI Linux cluster, and it was compared with several more traditional SS policies applied to non-dedicated environments.
Resumo:
The impact of personality and job characteristics on parental rearing styles was compared in 353 employees. Hypotheses concerning the relationships between personality and job variables were formulated in accordance with findings in past research and the Belsky’s model (1984). Structural equation nested models showed that Aggression-hostility, Sociability and job Demand were predictive of Rejection and Emotional Warmth parenting styles, providing support for some of the hypothesized relationships. The findings suggest a well-balanced association of personality variables with both parenting styles: Aggression-Hostility was positively related to Rejection and negatively to Emotional Warmth, whereas Sociability was positively related to Emotional Warmth and negatively related to Rejection. Personality dimensions explained a higher amount of variance in observed parenting styles. However, a model that considered both, personality and job dimensions as antecedent variables of parenting was the best representation of observed data, as both systems play a role in the prediction of parenting behavior.
Resumo:
A number of bacterial species, mostly proteobacteria, possess monothiol glutaredoxins homologous to the Saccharomyces cerevisiae mitochondrial protein Grx5, which is involved in iron–sulphur cluster synthesis. Phylogenetic profiling is used to predict that bacterial monothiol glutaredoxins also participate in the iron–sulphur cluster (ISC) assembly machinery, because their phylogenetic profiles are similar to the profiles of the bacterial homologues of yeast ISC proteins. High evolutionary cooccurrence is observed between the Grx5 homologues and the homologues of the Yah1 ferredoxin, the scaffold proteins Isa1 and Isa2, the frataxin protein Yfh1 and the Nfu1 protein. This suggests that a specific functional interaction exists between these ISC machinery proteins. Physical interaction analyses using low-definition protein docking predict the formation of strong and specific complexes between Grx5 and several components of the yeast ISC machinery. Two-hybrid analysis has confirmed the in vivo interaction between Grx5 and Isa1. Sequence comparison techniques and cladistics indicate that the other two monothiol glutaredoxins of S. cerevisiae, Grx3 and Grx4, have evolved from the fusion of a thioredoxin gene with a monothiol glutaredoxin gene early in the eukaryotic lineage, leading to differential functional specialization. While bacteria do not contain these chimaeric glutaredoxins, in many eukaryotic species Grx5 and Grx3/4-type monothiol glutaredoxins coexist in the cell.
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Proper dialogue between presynaptic neurons and their targets is essential for correct synaptic assembly and function. At central synapses, Wnt proteins function as retrograde signals to regulate axon remodeling and the accumulation of presynaptic proteins. Loss of Wnt7a function leads to defects in the localization of presynaptic markers and in the morphology of the presynaptic axons. We show that loss of function of Dishevelled-1 (Dvl1) mimics and enhances the Wnt7a phenotype in the cerebellum. Although active zones appear normal, electrophysiological recordings in cerebellar slices from Wnt7a/Dvl1 double mutant mice reveal a defect in neurotransmitter release at mossy fi ber–granule cell synapses. Deficiency in Dvl1 decreases, whereas exposure to Wnt increases, synaptic vesicle recycling in mossy fi bers. Dvl increases the number of Bassoon clusters, and like other components of the Wnt pathway, it localizes to synaptic sites. These fi ndings demonstrate that Wnts signal across the synapse on Dvl-expressing presynaptic terminals to regulate synaptic assembly and suggest a potential novel function for Wnts in neurotransmitter release.