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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Linux SMP

Ohlenroth, Matthias, Radke, Thomas 01 September 1998 (has links)
Vortrag UNIX-Stammtisch 09/96
12

Avaliação de Métodos para a Estimativa da Acidez Potencial para os solos dos Estados do Rio Grande do Sul e Mato Grosso / Evaluation of methods for estimating potential acidity in soils of Rio Grande do Sul and Mato Grosso States, Brazil

Guidotti, Rosane Maria Morales 30 September 2013 (has links)
Made available in DSpace on 2014-08-20T13:25:38Z (GMT). No. of bitstreams: 1 dissertacao_rosane_guidotti.pdf: 1652873 bytes, checksum: e165e27a1c291c18f1a683f1efc62a01 (MD5) Previous issue date: 2013-09-30 / Teaching and research activities in different areas of knowledge employ various chemicals substances, some of which are considered dangerous, offering potential risk to those who manipulate it or risk to the environment. The estimation of potential acidity (H + Al) in soils, made by SMP method uses two toxic reagents, p-nitrophenol and potassium chromate. To minimize toxic effect of these reagents, a new method called Sikora was proposed and tested in American soils, with positive results, which replaced them, respectively, by imidazole and the MES (2-N-morpholino ethanesulfonic acid monohydrate), not considered harmful. Sikora method has been tested in some Brazilian soils of Rio Grande do Sul State (RS) and from Central Brazil (Cerrado), and did not present a good correlation. For this reason, the Sikora method was modified and calibrated for these same soils and called Santa Maria buffer (TSM). This study aimed to evaluate the effectiveness of the original Sikora method and his version TSM in the estimation of the soil potential acidity in order to replace the SMP method calibrated for RS and Santa Catarina (SC) States, in a large group of soils, from RS and Mato Grosso (MT) States, with contrasting chemical and physical characteristics. The methods were tested using 110 soil samples from MT and 103 from RS, collected at 0-20 cm depth, in cultivated and uncultivated areas. The results were submitted to correlation analysis and descriptive statistics analysis. A second degree polynomial was adjusted to compare the potential acidity titrated with the pH values obtained with the three methods. Among methods, the higher accuracy in predicting the potential acidity was observed in the following order: SMP > TSM > Sikora, for both soils from RS State Southern and Planalto region as well for those of MT state. In RS state, the TSM method showed to be feasible to estimate potential acidity (H + Al) for soils of both regions, allowing the adoption of a single mathematical model. Only the SMP method presented universality in estimating potential acidity (H + Al) for soils of the two states, RS and MT. Sikora and TSM methods reproduced pH values obtained with SMP method for MT soils and therefore can be used for limestone recommendation. For RS State, the TSM method was more efficient than the Sikora method on the reproduction of soils pH values obtained with the SMP method, being the most suitable to replace SMP method in soil analysis laboratories and therefore to be used on limestone recommendation. / As atividades de ensino e pesquisa nas diversas áreas do conhecimento empregam várias substâncias químicas, sendo algumas consideradas perigosas, oferecendo risco potencial aqueles que as manipulam e ao meio ambiente. A estimativa da acidez potencial (H + Al) em solos, feita pelo método SMP, utiliza dois reagentes de caráter tóxico, o p-nitrofenol e o cromato de potássio. Para minimizar o efeito tóxico destes reagentes, foi proposto e testado com resultados positivos em solos americanos um método denominado Sikora, que os substituiu, respectivamente, pelo imidazol e pelo MES (ácido 2-N-morfolino etanosulfonico monohidratado), considerados menos tóxicos. No Brasil, o método Sikora foi testado em alguns solos do Estado do Rio Grande do Sul (RS) e do Cerrado. Como não apresentou uma boa correlação, o método foi modificado, calibrado para estes mesmos solos e denominado Tampão Santa Maria (TSM). O presente trabalho teve como objetivo avaliar a eficácia do método Sikora original e sua versão TSM na estimativa da acidez potencial num amplo grupo de solos, dos Estados do RS e do Mato Grosso (MT), com características químicas e físicas contrastantes, com vistas à substituição do método SMP calibrado para os Estados do RS e Santa Catarina (SC). Os métodos foram testados em 110 amostras de solos do MT e 103 amostras de solos dos RS, coletados na camada de 0-20 cm, em áreas cultivadas e não cultivadas. Os resultados foram submetidos a análises de correlação e estatística descritiva. Ajustou-se um polinômio de segundo grau para a comparação dos valores de pH obtidos com acidez potencial titulada e os três métodos. A maior acurácia na predição da acidez potencial foi observada na seguinte ordem entre os métodos avaliados: SMP>TSM>Sikora, tanto para solos das regiões Sul e Planalto do RS como para o Estado do MT. No RS, o método TSM mostrou-se viável em estimar acidez potencial (H + Al) para os solos das duas regiões do RS, possibilitando a adoção de um modelo matemático único. Apenas o método SMP apresentou universalidade na estimativa da acidez potencial (H + Al) para os dois Estados, RS e MT. O método Sikora e sua versão TSM reproduziram os valores de pH obtidos com o método SMP para os solos do MT e portanto podem ser usados para a recomendação de calcário. Para os solos do RS, o método TSM mostrou-se mais eficiente do que o método Sikora na reprodução dos valores de pH obtidos com o método SMP, sendo o mais indicado para substituí-lo nos laboratórios de análise de solos deste Estado e na recomendação de calcário.
13

Recomendação de calagem para alguns solos do Estado do Amazonas

Batista, Iza Maria Paiva 30 September 2014 (has links)
Submitted by Kamila Costa (kamilavasconceloscosta@gmail.com) on 2015-06-09T18:53:55Z No. of bitstreams: 1 Tese-Iza M P Batista.pdf: 592710 bytes, checksum: 0fdb23680dd259d50a1b08ec8415baa1 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-10T15:30:23Z (GMT) No. of bitstreams: 1 Tese-Iza M P Batista.pdf: 592710 bytes, checksum: 0fdb23680dd259d50a1b08ec8415baa1 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-10T15:36:33Z (GMT) No. of bitstreams: 1 Tese-Iza M P Batista.pdf: 592710 bytes, checksum: 0fdb23680dd259d50a1b08ec8415baa1 (MD5) / Made available in DSpace on 2015-06-10T15:36:33Z (GMT). No. of bitstreams: 1 Tese-Iza M P Batista.pdf: 592710 bytes, checksum: 0fdb23680dd259d50a1b08ec8415baa1 (MD5) Previous issue date: 2014-09-30 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Upland soils Amazonas state is characterized by having pH and Al3+ at levels that limit the good yields. The objective of this study was to evaluate the chemical changes in function in soils of the addition of different levels of limestone and estimate quantities needed corrective to reach pH arable. We used a completely randomized block design with three replications. The treatments consisted of a factorial 3 x 7 by matching three textural classes (medium texture, clay, and much clay) with seven levels of limestone (0, 1.0, 2.0, 4.0, 6.0, 8, 0 to 10 t ha-1). After 56 days of incubation, the pH values were determined in water; this was plotted versus liming and adjusted polynomial regression models, to determine the quantity of lime necessary to achieve pH 5.5; 6.0 and 6.5. At that time, it was determined the Al3+ content, Ca2+, Mg2+, K and H + Al and from these values calculated the base saturation (V%). The efficiency of liming by incubation curve method was evaluated in experiments conducted in a greenhouse through the effect of different rates of lime in the production of MSPA and MSR in the corn and bean crops. The treatments were arranged in a completely randomized design in a factorial 2 x 7, combining two soil (Ultisol and Oxisol) and seven levels of limestone (0, 1.0, 2.0, 4.0, 6.0, 8.0 and 10 t ha-1), with four replications. The data MSPA, MSR and content of P, K, Ca, Mg, Zn, Fe, Mn and Cu in the shoots were adjusted regression models and then estimated the limestone, corresponding to the ESM. The soil showed high significance indices with the amount of lime to raise the pH of the soil, and the levels of 0.3; 2.2 and 4.0; 2.6; 4.4 and 6.1; 2.2; 4.0 and 5.8 t ha-1 of lime in medium textured soils, clayey and much clayey are recommended to achieve the pH 5.5; 6.0 and 6.5, respectively. The recommendation of 1.5; 2.6 to 2.2 t ha-1 was sufficient to reduce Al3+ and the doses of 3.7; 4.7 and 4.6 t ha- 1 increasing the saturation to levels appropriate for crop development, corresponding to water pH around 6.3; 6.0 and 6.5 in medium textured soils, clayey and much clayey, respectively. The quantities of limestone corresponding to maximum economic yield MSPA and MSR both corn as the beans are close to the amount recommended by the method of incubation curve required to achieve the pH acceptable for cultivation and these doses have not reduced below the deficiency of the content absorption during the first 60 days of cultivation. / Os solos de terra firme do estado do Amazonas caracterizam-se por apresentar pH e Al3+ em níveis que limitam o bom rendimento das culturas. Objetivouse com o presente estudo, avaliar as modificações químicas nos solos em função da adição de diferentes níveis de calcário e estimar quantidades necessárias de corretivo para atingir pH agricultável. Utilizou-se um delineamento em blocos inteiramente casualizados, com três repetições. Os tratamentos foram constituídos de um fatorial 3 x 7, combinando três classes texturais (textura média, argilosa e muito argilosa) com sete doses de calcário (0; 1,0; 2,0; 4,0; 6,0; 8,0 e 10 t ha-1). Após 56 dias de incubação, determinaram-se os valores de pH em água, este foi plotado versus doses de calcário e ajustados a modelos de regressão polinomial, para determinar a quantidade de calcário necessária para atingir os valores de pH 5,5; 6,0 e 6,5. Nessa época, determinaram-se os teores de Al3+, Ca2+, Mg2+, K e H+Al e a partir desses valores calculou-se o índice de saturação por bases (V%). A eficiência da recomendação de calagem pelo método da curva de incubação foi avaliada em experimentos conduzidos em casa de vegetação por meio do efeito de diferentes doses de calcário na produção de MSPA e MSR nas culturas do milho e feijão. Os tratamentos foram dispostos em delineamento inteiramente casualizado num esquema fatorial 2 x 7, combinando dois solos (Argissolo e Latossolo) e sete doses de calcário (0; 1,0; 2,0; 4,0; 6,0; 8,0 e 10 t ha-1), com quatro repetições. Os dados de MSPA, MSR e conteúdo de P, K, Ca, Mg, Zn, Fe, Mn e Cu na parte aérea das plantas, foram ajustados a modelos de regressão e posteriormente estimadas as doses de calcário, correspondentes à MEE. Os solos estudados revelaram altos índices de significância com a necessidade de calcário para elevar o pH dos solos, sendo as doses de 0,3; 2,2 e 4,0; 2,6; 4,4 e 6,1; 2,2; 4,0 e 5,8 t ha-1 de calcário nos solos de textura média, argilosa e muito argilosa são recomendadas para atingirem o pH 5,5; 6,0 e 6,5, respectivamente. A recomendação de 1,5; 2,6 e 2,2 t ha-1 foi suficiente para reduzir o Al3+ e as doses de 3,7; 4,7 e 4,6 t ha-1 elevando a saturação por bases a níveis adequados para o desenvolvimento das culturas, correspondendo a pH em água em torno de 6,3; 6,0 e 6,5 nos solos de textura média, argilosa e muito argilosa, respectivamente. As quantidades de calcário correspondente ao máximo rendimento econômico de MSPA e MSR tanto no milho quanto no feijão aproximam-se da quantidade recomendada pelo método da curva de incubação necessária para atingir o pH aceitáveis para cultivo e essas doses não reduziram abaixo do teor de deficiência a absorção durante os 60 dias de cultivo.
14

Interaction of Hardware Transactional Memory and Microprocessor Microarchitecture

Diestelhorst, Stephan 10 July 2019 (has links)
Microprocessors have experienced a significant stall in single-thread performance since about 2004. Instead of significant annual performance improvements for a single core, it is easier to increase performance by providing multiple, independent cores that the application programmer has to coordinate. Exposing concurrency to the applications requires mechanisms to control it. Hardware Transactional Memory (HTM) is an abstraction that provides optimistic, fine-grained concurrency control with a simple application interface, and has received significant research attentions fro 2004 - 2010, with initial publications in the mid-90s. The central thesis of my work is that detailed analysis and ISA modelling of HTM is necessary to understand actual implementation and usage challenges, and get more realistic results. Instead of overly complicating the design of HTM with features that would be extremely hard to implement right in a more detailed microarchitecture and ISA proposal, I suggest that getting a base-line HTM specification and micro-architecture right is a challenge in itself. Yet, despite the complexity, there are interesting implementation options and extensions that can provide benefits to applications using HTM–but they are not on the trajectory taken by most papers published between 2004 and 2010.
15

Modelling and simulation of membrane bioreactors for wastewater treatment

Janus, Tomasz January 2013 (has links)
The work presented in this thesis leads to the formulation of a dynamic mathematical model of an immersed membrane bioreactor (iMBR) for wastewater treatment. This thesis is organised into three parts, each one describing a different set of tasks associated with model development and simulation. In the first part, the Author qualitatively and quantitatively compares various published activated sludge models, i.e. models of biochemical processes associated with bacterial growth, decay, lysis and substrate utilisation in activated sludge systems. As the thesis is focused on modelling membrane bioreactors (MBRs) which are known to experience membrane fouling as a result of adsorption of biopolymers present in the bulk liquid onto and within the membrane, all activated sludge models considered in this thesis are able to predict, with various levels of accuracy, the concentrations of biopolymeric substances, namely soluble microbial products (SMP) and extracellular polymeric substances (EPS). Some of the published activated sludge models dedicated to modelling SMP and EPS kinetics in MBR systems were unable to predict the SMP and EPS concentrations with adequate levels of accuracy, without compromising the predictions of other sludge and wastewater constituents. In other cases, the model equations and the assumptions made by their authors were questionable. Hence, two new activated sludge models with SMP and EPS as additional components have been formulated, described, and simulated. The first model is based on the Activated Sludge Model No. 1 (ASM1) whereas the second model is based on the Activated Sludge Model No. 3 (ASM3). Both models are calibrated on two sets of data obtained from a laboratory-scale system and a full-scale system and prove to be in very good agreement with the measurements. The second part of this thesis explains the development of two membrane fouling models. These models are set to describe the loss of membrane permeability during filtration of various solutions and suspensions. The main emphasis is placed on filtration of activated sludge mixtures, however the models are designed to be as general as feasibly possible. As fouling is found to be caused by a large number of often very complex processes which occur at different spatial as well as temporal scales, the two fouling models developed here have to consider a number of significant simplifications and assumptions. These simplifications are required to balance the model's accuracy, generality and completeness with its usability in terms of execution times, identifiability of parameters and ease of implementation in general purpose simulators. These requirements are necessary to ascertain that long term simulations as well as optimisation and sensitivity studies performed in this thesis either individually on fouling models or on the complete model of a MBR can be carried out within realistic time-scales. The first fouling model is based on an idea that fouling can be subdivided into just two processes: short-term reversible fouling and long-term irreversible fouling. These two processes are described with two first order ordinary differential equations (ODEs). Whilst the first model characterises the membrane filtration process from an observer's input-output point of view without any rigorous deterministic description of the underlying mechanisms of membrane fouling, the second model provides a more theoretical and in-depth description of membrane fouling by incorporating and combining three classical macroscopic mechanistic fouling equations within a single simulation framework. Both models are calibrated on a number of experimental data and show good levels of accuracy for their designated applications and within the intended ranges of operating conditions. In the third part, the first developed biological model (CES-ASM1) is combined with the behavioural fouling model and the links between these two models are formulated to allow complete simulation of a hollow fibre (HF) immersed membrane bioreactor (iMBR). It is assumed that biological processes affect the membrane through production of mixed liquor suspended solids (MLSS), SMP and EPS which cause pore blockage, cake formation, pore diameter constriction, and affect the specific cake resistance (SCR). The membrane, on the other hand, has a direct effect on the bulk liquid SMP concentration due to its SMP rejection properties. SMP are assumed to be solely responsible for irreversible fouling, MLSS is directly linked to the amount of cake depositing on the membrane surface, whereas EPS content in activated sludge affects the cake's SCR. Other links provided in the integrated MBR model include the effects of air scouring on the rate of particle back-transport from the membrane surface and the effects of MLSS concentration on oxygen mass transfer. Although backwashing is not described in great detail, its effects are represented in the model by resetting the initial condition in the cake deposition equation after each backwash period. The MBR model was implemented in Simulink® using the plant layout adopted in the MBR benchmark model of Maere et al. [160]. The model was then simulated with the inputs and operational parameters defined in [36, 160]. The results were compared against the MBR benchmark model of Maere et al. [160] which, contrary to this work, does not take into account the production of biopolymers, the membrane fouling, nor any interactions between the biological and the membrane parts of an MBR system.
16

Evaluation of SMP Shared Memory Machines for Use with In-Memory and OpenMP Big Data Applications

Younge, Andrew J., Reidy, Christopher, Henschel, Robert, Fox, Geoffrey C. 05 1900 (has links)
While distributed memory systems have shaped the field of distributed systems for decades, the demand for many-core shared memory resources is increasing. Symmetric Multiprocessor Systems (SMPs) have become increasingly important recently among a wide array of disciplines, ranging from Bioinformatics to astrophysics, and beyond. With the increase in big data computing, the size and scope of traditional commodity server systems is often outpaced. While some big data applications can be mapped to distributed memory systems found through many cluster and cloud technologies today, this effort represents a large barrier of entry that some projects cannot cross. Shared memory SMP systems look to effectively and efficiently fill this niche within distributed systems by providing high throughput and performance with minimized development effort, as the computing environment often represents what many researchers are already familiar with. In this paper, we look at the use of two common shared memory systems, the ScaleMP vSMP virtualized SMP deployment at Indiana University, and the SGI UV architecture deployed at University of Arizona. While both systems are notably different in their design, their potential impact on computing is remarkably similar. As such, we look to compare each system first under a set of OpenMP threaded benchmarks via the SPEC group, and to follow up with our experience using each machine for Trinity de-novo assembly. We find both SMP systems are well suited to support various big data applications, with the newer vSMP deployment often slightly faster; however, certain caveats and performance considerations are necessary when considering such SMP systems.
17

Définition et évaluation d'INUKTITUT : un interface pour l'environnement de programmation parallèle asynchrone Athapascan

LE KHAC, Nhien An 09 March 2005 (has links) (PDF)
Les grappes de calcul sont constituées par l'interconnexion de stations de travail par un réseau plus ou moins performant. Elles rencontrent un large succès dans le domaine du calcul scientifique. De nombreux protocoles et interfaces de programmation ont été développés pour exploiter ces grappes tels que Posix Threads, Marcel, Open MP, Socket, MPI, Madeleine, GM/Myrinet, Corba, etc. Pourtant la programmation d'une application ou le portage d'un environnement de programmation parallèle sur ces grappes est un travail difficile du fait de la complexité et la variété des caractéristiques de ces architectures et des bibliothèques disponibles. L'objectif de cette thèse est de définir et d'évaluer les performances d'INUKTITUT, un interface qui permet de porter efficacement et facilement sur des grappes des applications et des environnements de programmation parallèle de haut niveau comme Athapascan. INUKTITUT contient des fonctions pour multiprogrammation légère et pour les communications à base de message actif : le parallélisme intra-nœuds des processus, est géré à l'aide de processus légers communiquant par la mémoire partagée ; le parallélisme inter-nœuds est exploité par des communications basées sur des messages actifs. INUKTITUT est porté avec succès sur des systèmes aussi différents que Linux, Unix, MacOS X, Windows au dessus de TCP/IP, Myrinet ou Corba. Ce mémoire présente l'architecture d'INUKTITUT et les résultats d'évaluation des performances. Les deux applications principales utilisant INUKTITUT sont : Athapascan, un environnement de programmation parallèle et les KaTools, des outils pour le déploiement efficace de grandes grappes.
18

Effectiveness of Tracing in a Multicore Environment

Sivakumar, Narendran, Sundar Rajan, Sriram January 2010 (has links)
<p>Debugging in real time is imperative for telecommunication networks with their ever increasing size and complexity. In event of an error or an unexpected occurrence of event, debugging the complex systems that controls these networks becomes an insurmountable task. With the help of tracing, it is possible to capture the snapshot of a system at any given point of time. Tracing, in essence, captures the state of the system along with the programs currently running on the system. LTTng is one such tool developed to perform tracing in both kernel space and user space of an application. In this thesis, we evaluate the effectiveness of LTTng and its impact on the performance on the applications traced by it. As part of this thesis we have formulated a comprehensive load matrix to simulate varying load demands in a telecommunication network. We have also devised a detailed experimental methodology which encompasses a collection of test suites used to determine the efficiency of various LTTng trace primitives. We were also able to prove that, in our experiments, LTTng’s kernel tracing is more efficient than User Space Tracing and LTTng’s User Space Tracing has a performance impact of around three to five percent.</p>
19

Effectiveness of Tracing in a Multicore Environment

Sivakumar, Narendran, Sundar Rajan, Sriram January 2010 (has links)
Debugging in real time is imperative for telecommunication networks with their ever increasing size and complexity. In event of an error or an unexpected occurrence of event, debugging the complex systems that controls these networks becomes an insurmountable task. With the help of tracing, it is possible to capture the snapshot of a system at any given point of time. Tracing, in essence, captures the state of the system along with the programs currently running on the system. LTTng is one such tool developed to perform tracing in both kernel space and user space of an application. In this thesis, we evaluate the effectiveness of LTTng and its impact on the performance on the applications traced by it. As part of this thesis we have formulated a comprehensive load matrix to simulate varying load demands in a telecommunication network. We have also devised a detailed experimental methodology which encompasses a collection of test suites used to determine the efficiency of various LTTng trace primitives. We were also able to prove that, in our experiments, LTTng’s kernel tracing is more efficient than User Space Tracing and LTTng’s User Space Tracing has a performance impact of around three to five percent.
20

Erfahrungen bei der Installation und vergleichende Messungen zu verschiedenen MPI Implementierungen auf einem Dual Xeon Cluster

Trautmann, Sven 02 July 2003 (has links) (PDF)
Workshop Mensch-Computer-Vernetzung

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