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A Match_based Task Scheduling Algorithm for Heterogeneous EnvironmentChang, Ming-Jyh 29 August 2000 (has links)
Abstract
In this thesis we propose a match_based scheduling algorithm for heterogeneous environment. The major difference of our algorithm from other researches is that it considers the variation of computing power with time.
In our algorithm the each host is regarded as a group, their computing powers are sorted in ascending way and the ratio of each computing power with the total computing power is calculated. Similarly, the workload of tasks is classified and is sorted to the relative computing power in ascending way, then is assigned to one of host groups depending on the balance of computing power. The execution cost for each node of the task group is calculated from the task load and the computing power of host been assigned. In order to determine the priority of execution, the rank of each task is calculated from the total of the execution costs, maximum execution cost of its immediate successor, and the summation of ranks of all immediate successors.
Experiment results show that the proposed algorithm has better performance than DLS (Dynamic Level Scheduling)[12], HNF (Heavy Node First)[6], WLA (Weighted Length Algorithm)[6] and DPS (Dynamic Priority Scheduling)[18], especially, for heterogeneous environment.
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Evolution experimentale de la diversite en milieu heterogene / Experimental evolution of diversity in heterogeneous environmentsVenail, Patrick A. 24 March 2010 (has links)
Dans ce travail de thèse j'aborde d'un point de vue expérimental le rôle de l'hétérogénéité environnementale (spatiale et temporelle) comme moteur de diversification biologique. Il comporte une synthèse générale sur les principales thématiques abordées pendant ma thèse suivie d'une présentation des publications dérivées de mes propres recherches et de collaborations. Dans la synthèse je commence par présenter la biodiversité, je souligne l'importance d'étudier les conditions qui favorisent son émergence et son maintien pour mieux comprendre son organisation. Je présente le type de diversité biologique sur lequel se concentre mon travail ainsi que l'échelle d'organisation que j'ai considérée: la metacommunauté. J'évoque aussi l'intérêt croissant des écologistes pour prendre en considération les échelles évolutives dans les approches modernes des communautés. Plus loin, je présente l'évolution expérimentale comme l'outil qui m'a permis d'explorer les aspects écologiques et évolutifs du maintien et de l'émergence de la diversité en milieu hétérogène avant d'explorer certains de ces aspects théoriques. Pour finir, j'explore la relation diversité-fonctionnement comme une approche pour étudier les conséquences de l'actuel déclin de la biodiversité. Les trois premiers articles explorent différents aspects de la diversification de la bactérie Pseudomonas fluorescens SBW25 dans un environnement spatialement hétérogène (métacommunauté) après ~500 générations d'évolution. Les résultats des trois articles sont issus d'une même expérience d'évolution. Dans un premier article, j'ai exploré l'effet du niveau de dispersion sur la diversité régionale. Cette dernière s'est révélée maximale pour des niveaux de dispersion intermédiaires. Ce gradient de diversité à l'échelle régionale était lié avec une plus forte productivité résultant d'une meilleure complémentarité écologique. Dans le deuxième, j'ai mesuré la diversité à l'échelle locale (communautés) et j'ai montré une augmentation de la diversité pour des niveaux de dispersion intermédiaires (mass-effect) mais qui n'aboutit pas à une plus forte productivité. Cet article souligne l'importance de considérer l'échelle ainsi que les mécanismes de coexistence pour comprendre la relation entre diversité et fonctionnement des écosystèmes. Dans le troisième (en préparation) j'explore l'effet de la dispersion sur le patron d'adaptation locale. Les résultats préliminaires montrent qu'un patron d'adaptation locale n'est pas un résultat obligé de l'évolution en milieu spatialement hétérogène. Le niveau de dispersion semble modifier considérablement le patron d'adaptation avec une plus forte adaptation locale moyenne pour des niveaux de dispersion intermédiaire. Le quatrième article présente une nouvelle expérience d'évolution avec laquelle j'ai exploré le rôle du grain environnemental dans l'émergence et le maintien de la diversité dans un environnement temporellement fluctuant. Après ~300 générations d'évolution j'ai constaté que les traitements de grain intermédiaire présentaient la plus haute diversité. En temps que collaborateur j'ai également participé à la rédaction d'un article de revue sur le concept de spécialisation en écologie. Cet article inclut une synthèse des différentes définitions de ce concept ainsi que des méthodes pour la mesurer. Pour finir j'ai participé à la réalisation d'une expérience avec des bactéries marines Méditerranéennes visant à explorer la dynamique évolutive de la relation biodiversité-fonction dans des conditions favorisant soit la spécialisation écologique soit l'émergence de généralistes. Après 64 jours d'évolution, le résultat général est une relation positive entre productivité et richesse spécifique des assemblages. L'évolution de généralistes aboutit à une productivité moyenne plus forte que chez les spécialistes alors que la pente de la relation diversité –fonction est plus forte pour des spécialistes. / In this work I propose an experimental approach to the study of the impact of spatial and temporal environmental heterogeneity on biological diversification. It is composed of two main parts: first, a general review of the principal subjects I have explored during my thesis and then a presentation of the manuscripts from my own research and from different collaboration projects. In the synthesis I first present what is biological diversity (Biodiversity) and I underline the importance of considering the conditions to its emergence and maintenance in the understanding of its organization. I present the kind of diversity I'm interested in and the scale of organization I have considered: metacommunities. I also present the interest of current ecology research in including evolutionary processes on the modern concept of communities. Then, I present experimental evolution as a tool allowing the exploration of the ecological and evolutionary aspects of the maintenance and emergence of diversity in heterogeneous environments and I also present some of its theoretical aspects. Finally, I explore the biodiversity-ecosystem functioning relationship as a way to explore the consequences of diversity erosion. The first three manuscripts explore different aspects of a ~500 generation experiment of diversification of the bacteria Pseudomonnnas fluorescens SBW25 in a spatially heterogeneous environment (metacommunities). On the first manuscript, I have explored the effect of dispersal on regional diversity. The results show that diversity was maximal for intermediate dispersal levels. This gradient of diversity at the regional scale was positively related to a higher productivity as a result of higher ecological complementarity among genotypes. In a second article, I have measured the local diversity. The result was a higher increase in diversity at intermediate dispersal levels (mass-effect) but with no impact on productivity. This article underlines the importance of considering the mechanisms of coexistence when studying the diversity-ecosystem functioning relationship. Then, I present the preliminary results on the impact of dispersal on the pattern of local adaptation. The results show that a pattern of local adaptation is not an obligate outcome of evolution in spatially heterogeneous environments. Intermediate dispersal levels enhanced the emergence of local adaptation patterns. On a fourth article, I present the results of an experimental test of effect of the environmental grain on the emergence and maintenance of diversity in a temporally fluctuating environment by using Pseudomonas fluorescens SBW25. After ~300 generations of evolution, I have found that diversification was maximal at an intermediate environmental grain. I have also collaborated in the writing of a review about ecological specialization concept. This synthesis includes the different available definitions of ecological diversification and the different methods used to measure it. Finally, I have participated in an experiment using Mediterranean Sea bacteria exploring the dynamics of the diversity-ecosystem functioning relationship under too different selective scenarios favoring either specialization or the evolution of generalists. After 64 days of evolution, the result was a positive relationship between species richness and productivity for both specialists and generalists. Generalists performed better than specialists for any species richness level while the steepness of the relationship was higher for specialists.
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Hybrid Heterogeneous Routing Scheme for Improved Network Performance in WSNs for Animal TrackingBehera, Trupti M., Mohapatra, Sushanta K., Samal, Umesh C., Khan, Mohammad S. 01 June 2019 (has links)
Wireless Sensor Networks (WSNs) experiences several technical challenges such as limited energy, short transmission range, limited storage capacities, and limited computational capabilities. Moreover, the sensor nodes are deployed randomly and massively over an inaccessible or hostile region. Hence, WSNs are vulnerable to adversaries and are usually operated in a dynamic and unreliable environment. Animal tracking using wireless sensors is one such application of WSN where power management plays a vital role. In this paper, an energy-efficient hybrid routing method is proposed that divides the whole network into smaller regions based on sensor location and chooses the routing scheme accordingly. The sensor network consists of a base station (BS) located at a distant place outside the network, and a relay node is placed inside the network for direct communications from nodes nearer to it. The nodes are further divided into two categories based on the supplied energy; such that the ones located far away from BS and relay have higher energy than the nodes nearer to them. The network performance of the proposed method is compared with protocols like LEACH, SEP, and SNRP, considering parameters like stability period, throughput and energy consumption. Simulation result shows that the proposed method outperforms other methods with better network performance.
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Vývoj souborného katalogu ČR, základní problémové okruhy a varianty jejich řešení / The development of a Union Catalogue of the Czech Republic, the basic sets of problems and some variants of their solutionLodrová, Iveta January 2014 (has links)
This diploma thesis provides information about the Union Catalogue of the Czech Republic (SK ČR) and its new tasks related to Conception of development of libraries during the years 2011-2015. The aim is to show basic sets of problems, their analysis and some variants of their solutions, compared to other foreign union catalogues. The first and second part of the thesis deals with foreign union catalogues - British example of heterogeneous environment Copac: National, Academic and Specialist Catalogue, and Slovak example of homogeneous environment KIS3G, their analysis and development from the beginning to the present, current status and future plans. The third part describes SK ČR, including semi-structured interview with head of the Union Catalogues Department of the National Library, PhDr. Eva Svobodová and findings from SK ČR workgroup meeting. The final part presents the summary and comparison of the three union catalogues.
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MORPHO-PHYSIOLOGICAL AND GENOMICS ANALYSES REVEAL ADAPTATIONS OF HARDWOOD TREES TO ABIOTIC STRESSORSAziz Ebrahimi (14210135) 06 December 2022 (has links)
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<p>Rapid climate change on a global scale is posing a considerable threat to forest biodiversity. Assessing physiological and genomic backgrounds of each tree is crucial for informing conservation and mitigation strategies to evaluate species or populations' vulnerability and adaptive capacity under climate change. The goal of my dissertation research was to use morpho-physiological and molecular approaches in combination with genomic background, as a backbone knowledge for enhancing the restoration and conservation of different hardwood tree species. The same approaches also led to a better understanding of mitigation strategies of tree species to evaluate their vulnerability and adaptability under climate change. To do so, the native <em>Juglans</em> species (<em>J. cinerea</em> and <em>J. nigra</em>), local species (Arizona walnut<em>; J. major, </em>California walnut; <em>J. hindsii</em>), exotic species (Persian walnut, <em>J. regia</em>) and its F1 interspecific hybrids were used as a case study to evaluate the level of cold hardiness in <em>Juglans</em>. Hybridization can integrate biotic and abiotic tolerance in plants and could be a potential forest restoration and conservation tool. Evidence from past studies in some F1 interspecific hybrids indicates that naturalized hybrids of Persian walnut with black walnut or butternut have higher level of tolerance to lower temperature than Persian walnut. The potential cold tolerance of native, local, exotic <em>Juglans</em> species and F1 interspecific hybrid using field, electrolyte leakage, qPCR, and genome analysis was investigated, and results presented in chapter 2. Differences in cold hardiness were observed in tested <em>Juglans</em> species, <em>J. regia</em> as an exotic species and <em>J. major</em> from Arizona maladapted in West Lafayette, Indiana. No sign of cold damage was observed in F1 interspecific hybrids or native species. Using morpho-physiological, molecular, and genome data, we confirmed that molecular and morpho-physiological data were highly correlated and thus can be used to characterize cold hardy trait in <em>Juglans</em> species. </p>
<p>Although the native <em>Juglans</em> species are cold tolerant, with current trend of climate change and rapid tree migration to the northern range, it is not easy to predict how <em>Juglans</em> species may adapt to new environments and response to other biotic and abiotic stresses in future. A reference-genome assembly for nuclear and chloroplast genomes and cold hardy genes is presented in chapter 3. We used re-sequence genomes of 170 individuals collected from 20 <em>Juglans</em> species and <em>Carya</em> (as an outgroup) of the Juglandaceae family distributed in temperate-tropical forests of America and Asia. We integrate genome and temperature variables to identify a set of associated single-nucleotide polymorphisms (SNP), structural variations, and the geographical distribution of the variants in the genes related to local adaptation of <em>Juglans</em> across latitudes. Phylogeny analyses revealed that <em>Juglans</em> species were sorted based on their origin using the nuclear genome, cold-hardy genes, and organellar genome. <em>Juglans regia</em>, a native species of Asia and Europe, was distinct from other species and exhibited less genetic diversity than <em>Juglans</em> spp. of North America, based on whole genome and cold-hardy gene analysis. We identified the black walnut as a more diverse species and the California walnut and Persian walnut (<em>J. regia</em>) as less diverse species using selective sweep and heterozygosity analysis. Within <em>Juglans </em>species, those from colder areas exhibited higher diversity of cold hardy genes compared to the ones from warmer regions. Differences in genetic diversity among continents and latitudes did not follow a clear trend. Still, the level of gene diversity of <em>Juglans</em> from North America is higher than the species that originated in eastern Asia. We can use 65,000 nuclear SNPs variants in an ecological modeling system to predict genetic diversity and spatiotemporal shift of <em>Juglans</em> species in response to future climate change. These SNPs variants are helpful for forest tree breeding programs with aims such as marker-assisted selection (MAS), conservation or assisted migration in future. </p>
<p>Based on the findings of chapter 2 and 3, black walnut is the most diverse species with high genetic diversity in comparison with other <em>Juglans</em> species distributing across eastern forest of the USA. However, deeper knowledge of how this genetically diverse species will be affected by climate change is crucial. In chapter 3, we projected black walnut's current and future basal area. Utilizing machine learning, we tested different models using more than 1.4 million tree records from 10,162 Forest Inventory and Analysis (FIA) sample plots and 42 spatially explicit bioclimate and other environmental attributes. Ultimately, we used random forests (RF) model to estimate the basal area of black walnut under climate change. The mean of annual temperature and precipitation, potential evapotranspiration, topology, and human footprint were the most significant variables in prediction of basal area. Under two emission scenarios (Representative Concentration Pathway 4.5 and 8.5), the RF model projected that black walnut stocking will increase in the northern part of the current range in the USA by 2080, with a potential shift of species distribution range. However, uncertainty remains due to unpredictable events, including extreme abiotic (heat, drought) and biotic (pests, disease) occurrences. Our models can be adapted to other hardwood tree species to predict tree changes in the basal area based on future climate scenarios. </p>
<p>A similar approach of chapter 2, with a slightly different freeze test (whole plant freezing test) and use of cold-acclimated seedling was used in chapter 4. For cold acclimation, seedlings exposed to air temperatures progressively lowered for eight weeks (from 25.6/22.2 ºC to 8/4 ºC, day/night) and non-acclimated seedlings from sea level to 2,300 m, in tropical Hawaiʻi, USA to evaluate cold tolerance of koa. We also investigated gene expression using qPCR and wideseq sequencing in this study. Freezing tolerance varied significantly in non-acclimated versus cold-acclimated treatments across the elevation cline using the whole plant physiology-freezing test and gene expression. The level of freezing tolerance and the elevation at which seeds were collected were consistent with the frequency of freezing tolerance genes to facilitate variation interpretation in cold-hardy phenotypes. Findings of physiology and molecular data analysis for freezing tolerance of koa across the elevation gradient of the Hawaiian Islands provides insight into natural selection processes and will help to support forest restoration efforts. </p>
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FairCPU: Uma Arquitetura para Provisionamento de MÃquinas Virtuais Utilizando CaracterÃsticas de Processamento / FairCPU: An Architecture for Provisioning Virtual Machines Using Processing FeaturesPaulo Antonio Leal Rego 02 March 2012 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O escalonamento de recursos à um processo chave para a plataforma de ComputaÃÃo em Nuvem, que geralmente utiliza mÃquinas virtuais (MVs) como unidades de escalonamento. O uso de tÃcnicas de virtualizaÃÃo fornece grande flexibilidade com a habilidade de instanciar vÃrias MVs em uma mesma mÃquina fÃsica (MF), modificar a capacidade das MVs e migrÃ-las entre as MFs. As tÃcnicas de consolidaÃÃo e alocaÃÃo dinÃmica de MVs tÃm tratado o impacto da sua utilizaÃÃo como uma medida independente de localizaÃÃo. à geralmente aceito que o desempenho de uma MV serà o mesmo, independentemente da MF em que ela à alocada. Esta à uma suposiÃÃo razoÃvel para um ambiente homogÃneo, onde as MFs sÃo idÃnticas e as MVs estÃo executando o mesmo sistema operacional e aplicativos. No entanto, em um ambiente de ComputaÃÃo em Nuvem, espera-se compartilhar um conjunto composto por recursos heterogÃneos, onde as MFs podem variar em termos de capacidades de seus recursos e afinidades de dados. O objetivo principal deste trabalho à apresentar uma arquitetura que possibilite a padronizaÃÃo da representaÃÃo do poder de processamento das MFs e MVs, em funÃÃo de Unidades de Processamento (UPs), apoiando-se na limitaÃÃo do uso da CPU para prover isolamento de desempenho e manter a capacidade de processamento das MVs independente da MF subjacente. Este trabalho busca suprir a necessidade de uma soluÃÃo que considere a heterogeneidade das MFs presentes na infraestrutura da Nuvem e apresenta polÃticas de escalonamento baseadas na utilizaÃÃo das UPs. A arquitetura proposta, chamada FairCPU, foi implementada para trabalhar com os hipervisores KVM e Xen, e foi incorporada a uma nuvem privada, construÃda com o middleware OpenNebula, onde diversos experimentos foram realizados para avaliar a soluÃÃo proposta. Os resultados comprovam a eficiÃncia da arquitetura FairCPU em utilizar as UPs para reduzir a variabilidade no desempenho das MVs, bem como para prover uma nova maneira de representar e gerenciar o poder de processamento das MVs e MFs da infraestrutura. / Resource scheduling is a key process for cloud computing platform, which generally
uses virtual machines (VMs) as scheduling units. The use of virtualization techniques
provides great flexibility with the ability to instantiate multiple VMs on one physical machine
(PM), migrate them between the PMs and dynamically scale VMâs resources. The techniques
of consolidation and dynamic allocation of VMs have addressed the impact of its use as an
independent measure of location. It is generally accepted that the performance of a VM will be
the same regardless of which PM it is allocated. This assumption is reasonable for a homogeneous
environment where the PMs are identical and the VMs are running the same operating
system and applications. Nevertheless, in a cloud computing environment, we expect that a set
of heterogeneous resources will be shared, where PMs will face changes both in terms of their
resource capacities and as also in data affinities. The main objective of this work is to propose
an architecture to standardize the representation of the processing power by using processing
units (PUs). Adding to that, the limitation of CPU usage is used to provide performance isolation
and maintain the VMâs processing power at the same level regardless the underlying PM.
The proposed solution considers the PMs heterogeneity present in the cloud infrastructure and
provides scheduling policies based on PUs. The proposed architecture is called FairCPU and
was implemented to work with KVM and Xen hypervisors. As study case, it was incorporated
into a private cloud, built with the middleware OpenNebula, where several experiments were
conducted. The results prove the efficiency of FairCPU architecture to use PUs to reduce VMsâ
performance variability, as well as to provide a new way to represent and manage the processing
power of the infrastructureâs physical and virtual machines.
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