978 resultados para GLOBAL DEFECT SOLUTIONS
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In this paper a comparison between using global and local optimization techniques for solving the problem of generating human-like arm and hand movements for an anthropomorphic dual arm robot is made. Although the objective function involved in each optimization problem is convex, there is no evidence that the admissible regions of these problems are convex sets. For the sequence of movements for which the numerical tests were done there were no significant differences between the optimal solutions obtained using the global and the local techniques. This suggests that the optimal solution obtained using the local solver is indeed a global solution.
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We prove global well-posedness in the strong sense for stochastic generalized porous media equations driven by locally square integrable martingales with stationary independent increments.
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Campaign efforts by NGOs initially put conflict diamonds on the global radar screen in the late 1990s. In response, the Kimberley Process (KP), a negotiation forum between states, NGOs, and industry, was formed to discuss possible solutions to curb the trade in conflict diamonds. Less than three years later, a voluntary, global certification named the Kimberley Process Certification Scheme (KPCS) was adopted. The KPCS regulates the trade of rough diamonds by certifying all legitimate diamonds. This paper outlines the problem of conflict diamonds, how a global campaign raised awareness about the issue, and how the process of solution building unfolded in the KP. My analysis focuses on the diverse set of actors (NGOs, states, and industry) and their changing interactions over the course of the campaign and global regulation efforts. I conclude with several key lessons that capture important elements observed in this case study.
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Colloidal transport has been shown to enhance the migration of plutonium in groundwater downstream from contaminated sites, but little is known about the adsorption of ⁹⁰Sr and plutonium onto colloids in the soil solution of natural soils. We sampled soil solutions using suction cups, and separated colloids using ultrafiltration to determine the distribution of ²³⁹Pu and ⁹⁰Sr between the truly dissolved fraction and the colloidal fraction of the solutions of three Alpine soils contaminated only by global fallout from the nuclear weapon tests. Plutonium was essentially found in the colloidal fraction (>80%) and probably associated with organic matter. A significant amount of colloidal ⁹⁰Sr was detected in organic-rich soil solutions. Our results suggest that binding to organic colloids in the soil solutions plays a key role with respect to the mobility of plutonium in natural alpine soils and, to a lesser extent, to the mobility of ⁹⁰Sr.
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The conserved two-component regulatory system GacS/GacA determines the expression of extracellular products and virulence factors in a variety of Gram-negative bacteria. In the biocontrol strain CHA0 of Pseudomonas fluorescens, the response regulator GacA is essential for the synthesis of extracellular protease (AprA) and secondary metabolites including hydrogen cyanide. GacA was found to exert its control on the hydrogen cyanide biosynthetic genes (hcnABC) and on the aprA gene indirectly via a posttranscriptional mechanism. Expression of a translational hcnA'-'lacZ fusion was GacA-dependent whereas a transcriptional hcnA-lacZ fusion was not. A distinct recognition site overlapping with the ribosome binding site appears to be primordial for GacA-steered regulation. GacA-dependence could be conferred to the Escherichia coli lacZ mRNA by a 3-bp substitution in the ribosome binding site. The gene coding for the global translational repressor RsmA of P. fluorescens was cloned. RsmA overexpression mimicked partial loss of GacA function and involved the same recognition site, suggesting that RsmA is a downstream regulatory element of the GacA control cascade. Mutational inactivation of the chromosomal rsmA gene partially suppressed a gacS defect. Thus, a central, GacA-dependent switch from primary to secondary metabolism may operate at the level of translation.
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Pseudomonas aeruginosa undergoes spontaneous mutation that impairs secretion of several extracellular enzymes during extended cultivation in vitro in rich media, as well as during long-term colonization of the cystic fibrosis lung. A frequent type of strong secretion deficiency is caused by inactivation of the quorum-sensing regulatory gene lasR. Here we analyzed a spontaneously emerging subline of strain PAO1 that exhibited moderate secretion deficiency and partial loss of quorum-sensing control. Using generalized transduction, we mapped the secretion defect to the vfr gene, which is known to control positively the expression of the lasR gene and type II secretion of several proteases. We confirmed this secretion defect by sequencing and complementation of the vfr mutation. In a reconstruction experiment conducted with a 1:1 mixture of wild-type strain PAO1 and a vfr mutant of PAO1, we observed that the vfr mutant had a selective advantage over the wild type after growth in static culture for 4 days. Under these conditions, spontaneous vfr emerged in a strain PAO1 population after four growth cycles, and these mutants accounted for more than 40% of the population after seven cycles. These results suggest that partial or complete loss of quorum sensing and secretion can be beneficial to P. aeruginosa under certain environmental conditions.
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In groundwater applications, Monte Carlo methods are employed to model the uncertainty on geological parameters. However, their brute-force application becomes computationally prohibitive for highly detailed geological descriptions, complex physical processes, and a large number of realizations. The Distance Kernel Method (DKM) overcomes this issue by clustering the realizations in a multidimensional space based on the flow responses obtained by means of an approximate (computationally cheaper) model; then, the uncertainty is estimated from the exact responses that are computed only for one representative realization per cluster (the medoid). Usually, DKM is employed to decrease the size of the sample of realizations that are considered to estimate the uncertainty. We propose to use the information from the approximate responses for uncertainty quantification. The subset of exact solutions provided by DKM is then employed to construct an error model and correct the potential bias of the approximate model. Two error models are devised that both employ the difference between approximate and exact medoid solutions, but differ in the way medoid errors are interpolated to correct the whole set of realizations. The Local Error Model rests upon the clustering defined by DKM and can be seen as a natural way to account for intra-cluster variability; the Global Error Model employs a linear interpolation of all medoid errors regardless of the cluster to which the single realization belongs. These error models are evaluated for an idealized pollution problem in which the uncertainty of the breakthrough curve needs to be estimated. For this numerical test case, we demonstrate that the error models improve the uncertainty quantification provided by the DKM algorithm and are effective in correcting the bias of the estimate computed solely from the MsFV results. The framework presented here is not specific to the methods considered and can be applied to other combinations of approximate models and techniques to select a subset of realizations
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RESUME Les évidences montrant que les changements globaux affectent la biodiversité s'accumulent. Les facteurs les plus influant dans ce processus sont les changements et destructions d'habitat, l'expansion des espèces envahissantes et l'impact des changements climatiques. Une évaluation pertinente de la réponse des espèces face à ces changements est essentielle pour proposer des mesures permettant de réduire le déclin actuel de la biodiversité. La modélisation de la répartition d'espèces basée sur la niche (NBM) est l'un des rares outils permettant cette évaluation. Néanmoins, leur application dans le contexte des changements globaux repose sur des hypothèses restrictives et demande une interprétation critique. Ce travail présente une série d'études de cas investiguant les possibilités et limitations de cette approche pour prédire l'impact des changements globaux. Deux études traitant des menaces sur les espèces rares et en danger d'extinction sont présentées. Les caractéristiques éco-géographiques de 118 plantes avec un haut degré de priorité de conservation sont revues. La prévalence des types de rareté sont analysées en relation avec leur risque d'extinction UICN. La revue souligne l'importance de la conservation à l'échelle régionale. Une évaluation de la rareté à échelle globale peut être trompeuse pour certaine espèces car elle ne tient pas en compte des différents degrés de rareté que présente une espèce à différentes échelles spatiales. La deuxième étude test une approche pour améliorer l'échantillonnage d'espèces rares en incluant des phases itératives de modélisation et d'échantillonnage sur le terrain. L'application de l'approche en biologie de la conservation (illustrée ici par le cas du chardon bleu, Eryngium alpinum), permettrait de réduire le temps et les coûts d'échantillonnage. Deux études sur l'impact des changements climatiques sur la faune et la flore africaine sont présentées. La première étude évalue la sensibilité de 227 mammifères africains face aux climatiques d'ici 2050. Elle montre qu'un nombre important d'espèces pourrait être bientôt en danger d'extinction et que les parcs nationaux africains (principalement ceux situé en milieux xériques) pourraient ne pas remplir leur mandat de protection de la biodiversité dans le futur. La seconde étude modélise l'aire de répartition en 2050 de 975 espèces de plantes endémiques du sud de l'Afrique. L'étude propose l'inclusion de méthodes améliorant la prédiction des risques liés aux changements climatiques. Elle propose également une méthode pour estimer a priori la sensibilité d'une espèce aux changements climatiques à partir de ses propriétés écologiques et des caractéristiques de son aire de répartition. Trois études illustrent l'utilisation des modèles dans l'étude des invasions biologiques. Une première étude relate l'expansion de la laitue sáuvage (Lactuca serriola) vers le nord de l'Europe en lien avec les changements du climat depuis 250 ans. La deuxième étude analyse le potentiel d'invasion de la centaurée tachetée (Centaures maculosa), une mauvaise herbe importée en Amérique du nord vers 1890. L'étude apporte la preuve qu'une espèce envahissante peut occuper une niche climatique différente après introduction sur un autre continent. Les modèles basés sur l'aire native prédisent de manière incorrecte l'entier de l'aire envahie mais permettent de prévoir les aires d'introductions potentielles. Une méthode alternative, incluant la calibration du modèle à partir des deux aires où l'espèce est présente, est proposée pour améliorer les prédictions de l'invasion en Amérique du nord. Je présente finalement une revue de la littérature sur la dynamique de la niche écologique dans le temps et l'espace. Elle synthétise les récents développements théoriques concernant le conservatisme de la niche et propose des solutions pour améliorer la pertinence des prédictions d'impact des changements climatiques et des invasions biologiques. SUMMARY Evidences are accumulating that biodiversity is facing the effects of global change. The most influential drivers of change in ecosystems are land-use change, alien species invasions and climate change impacts. Accurate projections of species' responses to these changes are needed to propose mitigation measures to slow down the on-going erosion of biodiversity. Niche-based models (NBM) currently represent one of the only tools for such projections. However, their application in the context of global changes relies on restrictive assumptions, calling for cautious interpretations. In this thesis I aim to assess the effectiveness and shortcomings of niche-based models for the study of global change impacts on biodiversity through the investigation of specific, unsolved limitations and suggestion of new approaches. Two studies investigating threats to rare and endangered plants are presented. I review the ecogeographic characteristic of 118 endangered plants with high conservation priority in Switzerland. The prevalence of rarity types among plant species is analyzed in relation to IUCN extinction risks. The review underlines the importance of regional vs. global conservation and shows that a global assessment of rarity might be misleading for some species because it can fail to account for different degrees of rarity at a variety of spatial scales. The second study tests a modeling framework including iterative steps of modeling and field surveys to improve the sampling of rare species. The approach is illustrated with a rare alpine plant, Eryngium alpinum and shows promise for complementing conservation practices and reducing sampling costs. Two studies illustrate the impacts of climate change on African taxa. The first one assesses the sensitivity of 277 mammals at African scale to climate change by 2050 in terms of species richness and turnover. It shows that a substantial number of species could be critically endangered in the future. National parks situated in xeric ecosystems are not expected to meet their mandate of protecting current species diversity in the future. The second study model the distribution in 2050 of 975 endemic plant species in southern Africa. The study proposes the inclusion of new methodological insights improving the accuracy and ecological realism of predictions of global changes studies. It also investigates the possibility to estimate a priori the sensitivity of a species to climate change from the geographical distribution and ecological proprieties of the species. Three studies illustrate the application of NBM in the study of biological invasions. The first one investigates the Northwards expansion of Lactuca serriola L. in Europe during the last 250 years in relation with climate changes. In the last two decades, the species could not track climate change due to non climatic influences. A second study analyses the potential invasion extent of spotted knapweed, a European weed first introduced into North America in the 1890s. The study provides one of the first empirical evidence that an invasive species can occupy climatically distinct niche spaces following its introduction into a new area. Models fail to predict the current full extent of the invasion, but correctly predict areas of introduction. An alternative approach, involving the calibration of models with pooled data from both ranges, is proposed to improve predictions of the extent of invasion on models based solely on the native range. I finally present a review on the dynamic nature of ecological niches in space and time. It synthesizes the recent theoretical developments to the niche conservatism issues and proposes solutions to improve confidence in NBM predictions of the impacts of climate change and species invasions on species distributions.
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Digital Libraries (DLs) are extremely complex information systems that support the creation, management, distribution, and preservation of complex information resources, while allowing effective and efficient interaction among the several societies that benefit from DL content and services. In this paper, we focus on our experience facing challenges of building, maintaining, and developing the Networked University Digital Library (www.nudl.org), an extension of the Networked Digital Library of Theses and Dissertations (www.ndltd.org). NUDL is a worldwide initiative that addresses making the intellectual property produced in universities more accessible, stimulating international collaboration across all disciplines. We detail technological aspects of our solutions and research activities carried out to provide powerful and enriched services for the communities served by this initiative.
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While an adequate supply of food can be achieved at present for the current global population, sustaining this into the future will be difficult in the face of a steadily increasing population, increased wealth and a diminishing availability of fertile land and water for agriculture. This problem will be compounded by the new uses of agricultural products, for example, as biofuels. Wheat alone provides ≥20% of the calories and the protein for the world's population, and the value and need to increase the production is recognized widely. Currently, the world average wheat yield is around 3 t/ha but there is considerable variation between countries, with region-specific factors limiting yield, each requiring individual solutions. Delivering increased yields in any situation is a complex challenge that is unlikely to be solved by single approaches and a multidisciplinary integrated approach to crop improvement is required. There are three specific major challenges: increasing yield potential, protecting yield potential, and increasing resource use efficiency to ensure sustainability. Since the green revolution, yields at the farm gate have stagnated in many countries, or are increasing at less than half the rate required to meet the projected demand. In some countries, large gains can still be achieved by improvements in agronomy, but in many others the yield gains will only be achieved by further genetic improvement. In this overview, the problems and potential solutions for increased wheat yields are discussed, in the context of specific geographic regions, with a particular emphasis on China. The importance and the prospects for improvement of individual traits are presented. It is concluded that there are opportunities for yield increase but a major challenge will be avoiding a simultaneous increase in resource requirements.
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VALOSADE (Value Added Logistics in Supply and Demand Chains) is the research project of Anita Lukka's VALORE (Value Added Logistics Research) research team inLappeenranta University of Technology. VALOSADE is included in ELO (Ebusiness logistics) technology program of Tekes (Finnish Technology Agency). SMILE (SME-sector, Internet applications and Logistical Efficiency) is one of four subprojects of VALOSADE. SMILE research focuses on case network that is composed of small and medium sized mechanical maintenance service providers and global wood processing customers. Basic principle of SMILE study is communication and ebusiness insupply and demand network. This first phase of research concentrates on creating backgrounds for SMILE study and for ebusiness solutions of maintenance case network. The focus is on general trends of ebusiness in supply chains and networksof different industries; total ebusiness system architecture of company networks; ebusiness strategy of company network; information value chain; different factors, which influence on ebusiness solution of company network; and the correlation between ebusiness and competitive advantage. Literature, interviews and benchmarking were used as research methods in this qualitative case study. Networks and end-to-end supply chains are the organizational structures, which can add value for end customer. Information is one of the key factors in these decentralized structures. Because of decentralization of business, information is produced and used in different companies and in different information systems. Information refinement services are needed to manage information flows in company networksbetween different systems. Furthermore, some new solutions like network information systems are utilised in optimising network performance and in standardizingnetwork common processes. Some cases have however indicated, that utilization of ebusiness in decentralized business model is not always a necessity, but value-add of ICT must be defined case-specifically. In the theory part of report, different ebusiness and architecture models are introduced. These models are compared to empirical case data in research results. The biggest difference between theory and empirical data is that models are mainly developed for large-scale companies - not for SMEs. This is due to that implemented network ebusiness solutions are mainly large company centered. Genuine SME network centred ebusiness models are quite rare, and the study in that area has been few in number. Business relationships between customer and their SME suppliers are nowadays concentrated more on collaborative tactical and strategic initiatives besides transaction based operational initiatives. However, ebusiness systems are further mainly based on exchange of operational transactional data. Collaborative ebusiness solutions are in planning or pilot phase in most case companies. Furthermore, many ebusiness solutions are nowadays between two participants, but network and end-to-end supply chain transparency and information systems are quite rare. Transaction volumes, data formats, the types of exchanged information, information criticality,type and duration of business relationship, internal information systems of partners, processes and operation models (e.g. different ordering models) differ among network companies, and furthermore companies are at different stages on networking and ebusiness readiness. Because of former factors, different customer-supplier combinations in network must utilise totally different ebusiness architectures, technologies, systems and standards.
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Optimization models in metabolic engineering and systems biology focus typically on optimizing a unique criterion, usually the synthesis rate of a metabolite of interest or the rate of growth. Connectivity and non-linear regulatory effects, however, make it necessary to consider multiple objectives in order to identify useful strategies that balance out different metabolic issues. This is a fundamental aspect, as optimization of maximum yield in a given condition may involve unrealistic values in other key processes. Due to the difficulties associated with detailed non-linear models, analysis using stoichiometric descriptions and linear optimization methods have become rather popular in systems biology. However, despite being useful, these approaches fail in capturing the intrinsic nonlinear nature of the underlying metabolic systems and the regulatory signals involved. Targeting more complex biological systems requires the application of global optimization methods to non-linear representations. In this work we address the multi-objective global optimization of metabolic networks that are described by a special class of models based on the power-law formalism: the generalized mass action (GMA) representation. Our goal is to develop global optimization methods capable of efficiently dealing with several biological criteria simultaneously. In order to overcome the numerical difficulties of dealing with multiple criteria in the optimization, we propose a heuristic approach based on the epsilon constraint method that reduces the computational burden of generating a set of Pareto optimal alternatives, each achieving a unique combination of objectives values. To facilitate the post-optimal analysis of these solutions and narrow down their number prior to being tested in the laboratory, we explore the use of Pareto filters that identify the preferred subset of enzymatic profiles. We demonstrate the usefulness of our approach by means of a case study that optimizes the ethanol production in the fermentation of Saccharomyces cerevisiae.
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Diplomityö tehtiin Partek Oyj Abp:lle antamaan IT-järjestelmistä vastuussa oleville ja niihin tukeutuville johtohenkilöille yleisnäkemys IT-sovellusintegroinnista sekä luomaan ohjeet integrointi projekteihin. Diplomityön alkuosassa esitellään liiketoiminnan prosessien pulmakohtia ja sovellusintegrointien liiketoiminnalle tuomia etuja yleisellä tasolla perustuen kirjallisuuteen. Yleisen tason etuja saadaan mm. nopeampien prosessien, paremman tiedon saatavuuden ja ihmisille tulevien uusien toimintatapojen kautta tulevista eduista. Työn seuraavassa osiossa esitellään mitä sovellusintegraatio tarkoittaa käytännössä, mitä erilaisia vaihtoehtoja integroinneille on ja mitä etuja ja haittoja erilaisista integrointitavoista on. Integrointitavoista viesti-pohjainen integrointitapa on noussut suosituimmaksi sen yksinkertaisuuden, luotettavuuden ja helpon liitettävyyden takia. Integrointisovelluksilla on mahdollista siirtää, muokata, prosessoida ja varastoida viestejä. Näiden ominaisuuksien avulla on mahdollista luoda reaaliaikaisia yhteistyöverkostoja. Tämä osio perustuu kirjallisuuteen , artikkeleihin ja haastatteluihin. Kolmas osio keskittyy integrointi projektin ominaispiirteisiin luoden toimintakartan integrointiprojektin kululle. Osiossa esitellään huomioitavat tekniset asiat, kustannukset ja edut sekä mallipohjia integroinnin dokumentointiin. Osio perustuu omiin kokemuksiin, haastatteluihin sekä kirjallisuuteen. Neljännessä osiossa esitellään Partekissa tehty integrointiprojekti. Integrointityö tehtiin ostajille tarkoitetun toimittajarekisterin (PPM) ja ERP-järjestelmän (Baan) välillä. Integrointiin käytettiin yhtä suosituinta integrointityökalua nimeltään IBM WebSphere MQ.Osio perustuu projektin dokumentointiin, omiin kokemuksiin ja kirjallisuuteen. Diplomityön päättää yhteenveto. Kolme pääetua voidaan saavuttaa integroinneilla ja toimintakartalla; tiedon luotettavuus paranee, toimintakartalla saadaan integroinneille malli ja luodaan riippumattomuutta tiettyihin avain henkilöihin tarkalla dokumentoinnilla ja toimintatapojen standardoinnilla.
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Des que es va iniciar el segle, i a causa dels grans fluxos migratoris de procedències diverses, la població de Catalunya s’ha incrementat en més d’1 milió d’habitants. Diferents actors socials reivindiquen que un dels reptes presents en la societat catalana és reduir les diferències i en alguns casos les desigualtats que es detecten entre la població autòctona i la població d’origen estranger. Amb tot això, diversos autors afirmen que l’espai d’Educació Física de Primària és un espai òptim per atendre a la diversitat cultural, promoure els valors humans, la no discriminació entre l'alumnat i la cohesió i inclusió social. Amb tot aquest marc, apareix el professorat d’Educació Física de Primària i la competència intercultural com a agents de canvi per tal de promocionar la inclusió social en les seves sessions i de retruc en societat. En aquest Treball de Fi de Grau, s’intentarà analitzar i aportar solucions sobre algunes de les qüestions que afecten tant als Mestres d’Educació Física de Primària com a la competència intercultural a l’hora de promocionar la inclusió social del col•lectiu Marroquí, ja que aquest és més nombrós de població estrangera empadronada a Catalunya.
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Workflow management systems aim at the controlled execution of complex application processes in distributed and heterogeneous environments. These systems will shape the structure of information systems in business and non-business environments. E business and system integration is a fertile soil for WF and groupware tools. This thesis aims to study WF and groupware tools in order to gather in house knowledge of WF to better utilize WF solutions in future, and to focus on SAP Business Workflow in order to find a global solution for Application Link Enabling support for system integration. Piloting this solution in Nokia collects the experience of SAP R/3 WF tool for other development projects in future. The literary part of this study will guide to the world of business process automation providing a general description of the history, use and potentials of WF & groupware software. The empirical part of this study begins with the background of the case study describing the IT environment initiating the case by introducing SAP R/3 in Nokia, the communication technique in use and WF tool. Case study is focused in one solution with SAP Business Workflow. This study provides a concept to monitor communication between ERP systems and to increase the quality of system integration. Case study describes a way create support model for ALE/EDI interfaces. Support model includes monitoring organization and the workflow processes to solve the most common IDoc related errors.