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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

Méthodologie d'évaluation des performances environnementales de techniques en vue de les comparer puis de les valider "meilleures techniques disponibles

Cikankowitz, Anne 10 December 2008 (has links) (PDF)
La directive européenne, dite IPPC (Integrated Pollution Prevention and Control) impose aux industries à fort potentiel de pollution d‟avoir recours aux meilleures techniques disponibles (MTD) afin d‟atteindre un meilleur niveau de protection de l‟environnement dans l‟Union Européenne. La transposition des contraintes de cette directive européenne en législation française oblige notamment les industriels à réaliser une étude comparative de leur procédés de production à des techniques dites MTD, via un bilan de fonctionnement décennal. Ces MTD de référence sont regroupées par secteurs d‟activité dans des guides techniques élaborés au niveau européen (BREF). L‟analyse du contexte européen et français s‟est basée sur des entretiens et une étude bibliographique. Elle a montré que les principales difficultés résident dans la compréhension du concept de MTD et des guides techniques (les BREFs), dans le peu de synergie existant entre les parties prenantes mais aussi dans le manque de méthodologies d‟évaluation reconnues au regard de la directive IPPC, malgré douze considérations affichées par la directive dans son annexe IV. L‟évaluation et l‟application sont d‟autant moins aisées qu‟une technique est MTD en fonction du contexte local. La connaissance de la sensibilité du milieu récepteur est donc primordiale. Cette thèse propose une méthodologie d‟évaluation des performances environnementales de techniques en vue de les comparer puis de les valider ou non "meilleures techniques disponibles", en mettant en évidence les atouts et les limites de cette méthode. Sur un plan méthodologique, nous avons décidé de renforcer la légitimité de notre méthode en créant un groupe de travail volontaire, participant à la construction de la méthodologie L-BAT. Une démarche en quatre étapes a été créée ((1) analyse du niveau de performance des technologies au cas par cas (2) analyse du niveau de performance du système de gestion de l‟environnement et des risques (3) analyse du niveau de performance globale de l‟installation (4) analyse du niveau de performance de l‟installation avec prise en compte de la sensibilité des milieux). Trois outils sont associés à ces étapes ((1) une grille de lecture simplifiée d‟un BREF (2) un formulaire d‟évaluation thématique (3) une grille d‟évaluation de la sensibilité des milieux). En outre, notre méthodologie propose une grille d‟évaluation globale multi-milieux de la sensibilité du milieu local. Par ailleurs, une réflexion théorique a permis de positionner notre méthodologie par rapport à d‟autres méthodologies d‟évaluation existantes telles que l‟analyse du cycle de vie (ACV) ou l‟évaluation des performances environnementales (EPE).
12

Porting Linux on ARM-Based Micro-controllers

Tsai, Ju-Chin 30 July 2006 (has links)
More and more embedded systems choose ARM-based micro-controllers as CPU. If no embedded OS built with the system, the application scope will be restricted. Therefore, the need of embedded OS is vital. There are many embedded OS¡¦s in the market, but the embedded Linux has many advantages and is widely accepted. Commercial embedded Linux takes less refund than other embedded OS¡¦s. The kernel and most applications are distributed in GPL open source copyright, and is highly portable to many machine platforms. Presently, the hardware key-technology is highly skilled. The margin of 3C industrial has gone down rapidly. Therefore, people focus on adapting integrated technology to practicality and innovation to make cost down. Developers choose appropriate ARM micro-controllers according to demanding functionality of their products. The microcontroller is not necessary running with Linux distribution. Two approaches can be used to resolve the embedded OS issue. The first approach is porting Linux to the platform without any refund. The second approach is to pay for commercial Linux. Embedded system peripheral devices aim at powerful functionalities and economy. For instance, UART interface is cheap and low data transfer rate. The target board communicates with host via RS-232. RS-232 acts as serial console to play dumb terminal under Linux. Industrial applications often make use of RS-xxx for UART physical transmission layer. For instance, RS-485 applies modbus protocol to build cheap monitor systems. Network transmission is a necessary function, and it generally achieves high data transfer rate application through Ethernet. The UNIX-like network socket has served network application very well. Embedded systems are usually diskless systems. In order to keep permanent data, using flash memory as block disk system is a widely adapted strategy and which operates flash memory through MTD subsystems¡][28]¡^. An MTD subsystem contains two different modules, ¡§user¡¨and ¡§driver¡¨. In the driver module, CFI¡][40]¡^ is applied to probe flash chip, partition it and provide operating function. Flash translation layer and file-system are applied in the user module. MTD BLOCK is used to emulate the flash partitions as block devices which are then mounted into Linux virtual file system¡]VFS¡^with JFFS2 type, designed according to the feature of flash devices. In this thesis, we will describe in detail the procedure of porting Linux to ARM micro-controllers. The motivation of the work is introduced in chapter 1. In chapter 2, we introduce development tools and the main flow of the porting procedure. In chapter 3, we describe the LH79525 platform and the main perepherals on the target board, then introduce the ARM programmer model. In chapter 4, we examine the required knowledge and the important issues for porting ARM Linux. In chapter 5, we describe the details of porting Linux to run with Sharp LH79525, including modifying the key source codes and adjusting kernel configuration for embedding the UART, ethernet MAC, and MTD subsystem. In chapter 6, we do step-by-step validation and apply an integrated application with the LF-314CP temperature controller¡][46]¡^ by law-chain technology for the LH79525 target board running with the ported ARM Linux. In chapter 7, we present some issues for future work and improvement, then make a conclusion for the thesis.
13

Gr?fico de controle modificado para processos com estruturas complexas de autocorrela??o

Costa, Renato Tigre Martins da 29 April 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-31T23:54:17Z No. of bitstreams: 1 RenatoTigreMartinsDaCosta_DISSERT.pdf: 1398473 bytes, checksum: 5259c2bb8b8df69f928b864b5cdaf972 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-05T22:15:41Z (GMT) No. of bitstreams: 1 RenatoTigreMartinsDaCosta_DISSERT.pdf: 1398473 bytes, checksum: 5259c2bb8b8df69f928b864b5cdaf972 (MD5) / Made available in DSpace on 2016-04-05T22:15:41Z (GMT). No. of bitstreams: 1 RenatoTigreMartinsDaCosta_DISSERT.pdf: 1398473 bytes, checksum: 5259c2bb8b8df69f928b864b5cdaf972 (MD5) Previous issue date: 2015-04-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Este trabalho prop?e um gr?fico de controle modificado incorporando conceitos de an?lise de s?ries temporais. Especificamente, n?s consideramos os modelos de distribui??o de transi- ??o e mistura gaussianas (GMTD). Os modelos GMTD s?o uma classe mais geral do que os modelos da fam?lia autoregressiva (AR), no sentido de que os processos autocorrelacionados podem apresentar trechos planos (plat?s), explos?es ou outliers. Neste cen?rio os Gr?ficos de Shewhart tradicionais n?o s?o mais ferramentas adequadas para o acompanhamento desses processos. Portanto, Vasilopoulos e Stamboulis (1978) propuseram uma vers?o modificada dos gr?ficos, considerando limites de controle adequados com base em processos autocorrelacionados. A fim de avaliar a efici?ncia da t?cnica proposta uma compara??o com um gr?fico tradicional Shewhart (que ignora a estrutura de autocorrela??o do processo), o gr?fico de controle Shewhart AR(1) e um gr?fico de controle Shewhart GMTD foi feita. Uma express?o anal?tica para a vari?ncia processo, assim como os limites de controle foram desenvolvidos para um modelo GMTD particular. O ARL ? utilizado como crit?rio para medir a efici?ncia dos gr?ficos de controle. A compara??o foi feita com base em uma s?rie gerada de acordo com um modelo GMTD. Os resultados apontam para a dire??o que os gr?ficos modificados Shewhart GMTD t?m um melhor desempenho do que o Shewhart AR(1) e o Shewhart tradicional. / This work proposes a modified control chart incorporating concepts of time series analysis. Specifically, we considerer Gaussian mixed transition distribution (GMTD) models. The GMTD models are a more general class than the autorregressive (AR) family, in the sense that the autocorrelated processes may present flat stretches, bursts or outliers. In this scenario traditional Shewhart charts are no longer appropriate tools to monitoring such processes. Therefore, Vasilopoulos and Stamboulis (1978) proposed a modified version of those charts, considering proper control limits based on autocorrelated processes. In order to evaluate the efficiency of the proposed technique a comparison with a traditional Shewhart chart (which ignores the autocorrelation structure of the process), a AR(1) Shewhart control chart and a GMTD Shewhart control chart was made. An analytical expression for the process variance, as well as control limits were developed for a particular GMTD model. The ARL was used as a criteria to measure the efficiency of control charts. The comparison was made based on a series generated according to a GMTD model. The results point to the direction that the modified Shewhart GMTD charts have a better performance than the AR(1) Shewhart and the traditional Shewhart.
14

Stochastic process analysis for Genomics and Dynamic Bayesian Networks inference.

Lebre, Sophie 14 September 2007 (has links) (PDF)
This thesis is dedicated to the development of statistical and computational methods for the analysis of DNA sequences and gene expression time series.<br /><br />First we study a parsimonious Markov model called Mixture Transition Distribution (MTD) model which is a mixture of Markovian transitions. The overly high number of constraints on the parameters of this model hampers the formulation of an analytical expression of the Maximum Likelihood Estimate (MLE). We propose to approach the MLE thanks to an EM algorithm. After comparing the performance of this algorithm to results from the litterature, we use it to evaluate the relevance of MTD modeling for bacteria DNA coding sequences in comparison with standard Markovian modeling.<br /><br />Then we propose two different approaches for genetic regulation network recovering. We model those genetic networks with Dynamic Bayesian Networks (DBNs) whose edges describe the dependency relationships between time-delayed genes expression. The aim is to estimate the topology of this graph despite the overly low number of repeated measurements compared with the number of observed genes. <br /><br />To face this problem of dimension, we first assume that the dependency relationships are homogeneous, that is the graph topology is constant across time. Then we propose to approximate this graph by considering partial order dependencies. The concept of partial order dependence graphs, already introduced for static and non directed graphs, is adapted and characterized for DBNs using the theory of graphical models. From these results, we develop a deterministic procedure for DBNs inference. <br /><br />Finally, we relax the homogeneity assumption by considering the succession of several homogeneous phases. We consider a multiple changepoint<br />regression model. Each changepoint indicates a change in the regression model parameters, which corresponds to the way an expression level depends on the others. Using reversible jump MCMC methods, we develop a stochastic algorithm which allows to simultaneously infer the changepoints location and the structure of the network within the phases delimited by the changepoints. <br /><br />Validation of those two approaches is carried out on both simulated and real data analysis.
15

A produção do espaço e a relação rural urbano : do Movimento dos Trabalhadores Desempregados (MTD), em Vitória da Conquista - BA

Menezes, Hilário José 23 August 2011 (has links)
This research aims to discuss and analyze the process of territorialization of the Movimento dos Trabalhadores Desempregados (MTD) and the rural / urban connexion, with the object of study the social subjects who participate in the MTD, in Vitória da Conquista, Bahia, directly affected by unemployment and homelessness. Establishing a counterpoint to the current economic model, some organized social movements fighting for the democratization of access to land and believe that only land reform can solve this problem. As a research methodology, this study used the critical-dialectical method, the life history, and discourse analysis as a tool for analysis of data collected through participant observation, field diary, recording descriptive and semi-structured interviews. Specifically, we analyzed the Settlement Zumbi dos Palmares, located in Vitória da Conquista, Bahia, realized from the political struggle implemented by the MTD. The results indicate that the MTD was inspired by the debates established by Consulta Popular to implement the goals of struggle, based on the creation of spaces and collective projects from the reality experienced by people priced out of access to land and employment. Furthermore, we observed that the history of struggle is part of the MTD of the contemporary context of the implementation of housing policies for low income and who live in risk areas. It follows therefore that the social pressure exerted by social movements shows to society and to the needs of public housing and work for a portion of society living in precarious conditions. / Esta pesquisa tem como finalidade discutir e analisar o processo de territorialização do Movimento dos Trabalhadores Desempregados (MTD) e a relação campo/cidade, tendo como objeto de estudo os sujeitos sociais que participam do MTD, no município de Vitória da Conquista-BA, diretamente atingidos pelo desemprego e pela falta de moradia. Estabelecendo um contraponto ao modelo econômico vigente, alguns movimentos sociais organizados lutam pela democratização do acesso a terra e acreditam que só a reforma agrária poderá resolver este problema. Como metodologia de pesquisa, este trabalho utilizou o método crítico-dialético, tendo a história de vida e a análise do discurso como instrumentos de análise dos dados coletados, por meio de observação participante, diário de campo, registro descritivo e entrevistas semiestruturadas. Especificamente, foi analisado o Assentamento Zumbi dos Palmares, localizado em Vitória da Conquista-BA, concretizado com base na luta política implementada pelo MTD. Os resultados encontrados apontam que o MTD se inspirou nos debates estabelecidos pela Consultar Popular para implementar os seus objetivos de luta, com base na criação de espaços e projetos coletivos face à realidade vivida por cidadãos alijados do acesso a terra e ao emprego. Além disso, observou-se que a história de luta do MTD é parte do contexto contemporâneo da implementação de políticas de habitação para pessoas de baixa renda e que moram em áreas de riscos. Conclui-se, portanto, que a pressão social exercida pelos movimentos sociais mostra para a sociedade e para o poder público as carências de habitação e trabalho para uma parcela da sociedade que vive em condições precárias.
16

Software-defined Situation-aware Cloud Security

January 2020 (has links)
abstract: The use of reactive security mechanisms in enterprise networks can, at times, provide an asymmetric advantage to the attacker. Similarly, the use of a proactive security mechanism like Moving Target Defense (MTD), if performed without analyzing the effects of security countermeasures, can lead to security policy and service level agreement violations. In this thesis, I explore the research questions 1) how to model attacker-defender interactions for multi-stage attacks? 2) how to efficiently deploy proactive (MTD) security countermeasures in a software-defined environment for single and multi-stage attacks? 3) how to verify the effects of security and management policies on the network and take corrective actions? I propose a Software-defined Situation-aware Cloud Security framework, that, 1) analyzes the attacker-defender interactions using an Software-defined Networking (SDN) based scalable attack graph. This research investigates Advanced Persistent Threat (APT) attacks using a scalable attack graph. The framework utilizes a parallel graph partitioning algorithm to generate an attack graph quickly and efficiently. 2) models single-stage and multi-stage attacks (APTs) using the game-theoretic model and provides SDN-based MTD countermeasures. I propose a Markov Game for modeling multi-stage attacks. 3) introduces a multi-stage policy conflict checking framework at the SDN network's application plane. I present INTPOL, a new intent-driven security policy enforcement solution. INTPOL provides a unified language and INTPOL grammar that abstracts the network administrator from the underlying network controller's lexical rules. INTPOL develops a bounded formal model for network service compliance checking, which significantly reduces the number of countermeasures that needs to be deployed. Once the application-layer policy conflicts are resolved, I utilize an Object-Oriented Policy Conflict checking (OOPC) framework that identifies and resolves rule-order dependencies and conflicts between security policies. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2020
17

Computational Fluid Dynamics Modelling of Incompressible Flow and Mixing in Continuous Microreactors

D'Orazio, Antonio 23 April 2021 (has links)
Continuous milli-scale and micro-scale structures such as FlowPlate® microreactors have emerged as a promising element of process intensification due to their inherently effective rates of mass and heat transfer. These microfluidic devices have proven to be a preferred solution in place of energy-intensive batch processes for certain pathways of fine chemical and pharmaceutical synthesis, most notably fast reactions taking place on the scale of milliseconds to seconds. Computational fluid dynamics (CFD) has become an increasingly valuable tool in the field of microreactor design and optimization for its ability to locally map complex fluid flow patterns and resolve microscopic scales of reactive mixing that are challenging to characterize experimentally. The primary objective of this research was thus to develop and validate a mathematical model for the simulation of chaotic flow and homogeneous mixing in continuous microreactors. The model needed to be versatile enough to handle transition between flow regimes within a given reactor as well as the coexistence of both chaotic and laminar flow patterns in the micromixing elements that comprise said reactors. This was successfully achieved through the implementation of a k-ω SST (shear-stress transport) turbulence model that accounts for the impact of small-scale temporal and spatial fluctuations generated in the micromixer geometries studied herein; be it a liquid-liquid mixer (LLM), a serpentine (SZ) or a tangential (TG) mixer. In a first CFD study, the computational predictions were validated based on excellent agreement with experimental pressure loss (R^2 > 0.997) and residence time distribution (RTD) data (R^2 > 0.97) in several LL microreactors at Reynolds numbers ranging from 210 to 2140. Furthermore, the local velocity distribution and streamlines were mapped across the 3D domain of these reactors and it was discovered, based on the emergence of advective recirculation zones and turbulent dispersion, that a drastic change in flow behaviour occurred in these mixing elements at a Reynolds number of about 640. The interspacing of LLM elements with straight microchannels proved to be a suitable approach to modulating pressure loss while concurrently maintaining the chaotic secondary flow patterns generated from the mixers. In a second CFD study, the impact of micromixer geometry on the local velocity fields and advective transport performance was investigated both from a macromixing and micromixing perspective. Like the LLM, the SZ and TG mixers conferred chaotic secondary flow patterns at characteristic Reynolds numbers between 500 and 1000. As such, it was concluded that it would be ideal to operate these mixers at water flow rates of at least 30 ml/min. Contour plots of the velocity magnitude coupled with the computation of RTD showed that the SZ virtually mimics a plug-flow profile over a volume of 77 mm3 or greater at 50 g/min. The RTD of the LLM and TG resembles that of a mixed flow pattern given that approximately 65-80% of their fluid volume is occupied by recirculation zones. As such, it required 65 LLMs in series (3105 mm3) and 80 TGs (1142 mm3) to approach the same pattern as 10 SZs (77 mm3) from a macromixing perspective. Micromixing time distributions (MTD) were also characterized by locally computing the decay time of small-scale segregation (t_SSS) as a function of flow rate, wherein higher flow rates generated lower characteristic mixing times. The TG and LLM conferred the broadest range of mixing times, spanning nearly four orders of magnitude in the range of [0.02 ms, 10 ms], whereas the SZ generated a much narrower MTD ranging between [0.024 ms, 0.69 ms]. Finally, the impact of geometry and flow conditions on reaction yield was assessed by characterizing the extent of a finite-rate reaction relative to an infinitely fast reaction taking place in parallel. The calculated yield for the competitive-parallel reaction scheme showed that the second Damköhler number (Dall) computed based on the mean tSSS provides useful information about whether the process will be limited by the intrinsic rate of reaction or by the rate of mass transfer, even though the reaction process is controlled by a combination of the RTD as well as loss of LSS and SSS. It was concluded that the change in MTD as a function of power dissipation should coincide with the reaction yield response, and that any deviation in that relationship is because of macroscopic blending of reactants in the entrance region.
18

Model-Based Optimization of Clinical Trial Designs

Vong, Camille January 2014 (has links)
General attrition rates in drug development pipeline have been recognized as a necessity to shift gears towards new methodologies that allow earlier and correct decisions, and the optimal use of all information accrued throughout the process. The quantitative science of pharmacometrics using pharmacokinetic-pharmacodynamic models was identified as one of the strategies core to this renaissance. Coupled with Optimal Design (OD), they constitute together an attractive toolkit to usher more rapidly and successfully new agents to marketing approval. The general aim of this thesis was to investigate how the use of novel pharmacometric methodologies can improve the design and analysis of clinical trials within drug development. The implementation of a Monte-Carlo Mapped power method permitted to rapidly generate multiple hypotheses and to adequately compute the corresponding sample size within 1% of the time usually necessary in more traditional model-based power assessment. Allowing statistical inference across all data available and the integration of mechanistic interpretation of the models, the performance of this new methodology in proof-of-concept and dose-finding trials highlighted the possibility to reduce drastically the number of healthy volunteers and patients exposed to experimental drugs. This thesis furthermore addressed the benefits of OD in planning trials with bio analytical limits and toxicity constraints, through the development of novel optimality criteria that foremost pinpoint information and safety aspects. The use of these methodologies showed better estimation properties and robustness for the ensuing data analysis and reduced the number of patients exposed to severe toxicity by 7-fold.  Finally, predictive tools for maximum tolerated dose selection in Phase I oncology trials were explored for a combination therapy characterized by main dose-limiting hematological toxicity. In this example, Bayesian and model-based approaches provided the incentive to a paradigm change away from the traditional rule-based “3+3” design algorithm. Throughout this thesis several examples have shown the possibility of streamlining clinical trials with more model-based design and analysis supports. Ultimately, efficient use of the data can elevate the probability of a successful trial and increase paramount ethical conduct.
19

Propuesta metodológica para la aplicación de AHP y ANP al proceso de toma de decisiones asociado a la evaluación de la autorización ambiental integrada

Giner Santonja, Germán 15 December 2010 (has links)
La Directiva 2008/1/CE, de Prevención y Control Integrados de la Contaminación (IPPC, por sus siglas en inglés), se transpuso al ordenamiento jurídico español por la Ley 16/2002, la cual creó una nueva figura administrativa, la Autorización Ambiental Integrada (AAI). Para poder otorgar la AAI, la Administración ambiental competente debe realizar una Evaluación Ambiental de la actividad IPPC (EA-IPPC), la cual tendrá en cuenta todos los factores afectados y/o relacionados de algún modo con la actividad, desde la fase de proyecto hasta su ejecución y posterior explotación. El resultado de dicha Evaluación Ambiental se plasmará en una resolución, que contendrá todos los condicionantes que la actividad deba cumplir para su puesta en marcha y/o explotación. Dada la alta complejidad que supone integrar todos los valores promovidos por la Directiva IPPC, y que la metodología actual empleada por la Administración presenta deficiencias, surge la motivación para desarrollar esta Tesis Doctoral, con el objetivo de proponer una nueva metodología para la EA-IPPC, a la cual se denominará en adelante Evaluación de la Autorización Ambiental Integrada (EAAI). La EAAI constituye una aplicación del concepto de racionalidad procedimental multicriterio. Las incertidumbres y los agujeros de información, así como las limitaciones cognitivas en el PTD, son todos, en diferente grado, peculiaridades típicas de la toma de decisiones ambientales. En este sentido, la EAAI mira más allá de la predicción de las consecuencias ambientales de la decisión y asegura que un conjunto de criterios de decisión, que garanticen que se están tomando en cuenta los valores sustantivos IPPC, se apliquen efectivamente al proceso de toma de decisiones. Se ha puesto en práctica la evaluación de las MTD mediante técnicas de decisión multicriterio sobre un caso real de de AAI concedida. Se ha propuesto una aplicación innovadora de las técnicas de AHP y ANP para la evaluación de las mismas MTD. / Giner Santonja, G. (2010). Propuesta metodológica para la aplicación de AHP y ANP al proceso de toma de decisiones asociado a la evaluación de la autorización ambiental integrada [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8980 / Palancia
20

Mechanismus pro upgrade BIOSu v Linuxu / Generic BIOS Update Mechanism for Linux

Mariščák, Igor January 2008 (has links)
This work provides overview of creating of a simple driver for the BIOS flash memory by accessing the physical computer memory. Although, the BIOS is one of a system's core components, there is no standardized update mechanism approach. Purpose of thesis is to create module driver by taking advantage of existing interface subsystem MTD, to suggest and implement driver for one specific device to Linux kernel operating system. Also explains technique allowing write access to registers of the flash memory with utilization of configuration file.

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