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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.
1

ERP sistemų funkcionalumo ir vartotojo reikalavimų sutapatinimo modelis / The model of matching ERP system functionality to customer requirements

Žydelis, Paulius 10 January 2006 (has links)
This work treats the importance of Enterprise Resource Planning (ERP) system and problems that face users. One of the biggest problem is how to choose the right system spending less time and money. The purpose of this work is to design the method of matching requirements raised by system and customer, and to implement this method by creating model which will collect, match and return acceptable results to customer.
2

Läshastighet i en bok, på en dator och i en smartphone – en fallstudie av fem flickor - Reading speed in a book, a computer and a smartphone -A case study of five girls

Holmgren, Mikael January 2013 (has links)
Arbetet behandlar frågan om elever läser olika snabbt beroende på varifrån de läser en text? Studiens grundläggande syfte är att undersöka om det föreligger någon skillnad i läshastighet i en bok, på en dator eller i en så kallad smartphone? Undersökningsgruppen är fem slumpmässigt utvalda flickor i årskurs 8. Intresset för arbetet tar sin grund i ett stort eget intresse för läsning men också i deltagande vid insamlandet av data till en större studie i ämnet. Studien har för avsikt att jämföra lästeknik och förståelse i en bok, på en dator och i smartphones. Som en del två skall försök göras för att utveckla lästekniken genom mental teknik- lånad från idrotten - i avsikt att utveckla elevers läsförmåga och uppfattningsmöjlighet.Metoden som används i är i detta arbete en fallstudie samt en analys utifrån observationer av deltagarna. Dessa filmas när de läser och sen analyseras filmerna utifrån antal ord per minut (opm) från en bok, en dator och en telefon. Metoden är till viss del egendesignad vilket den kan få kritik för men validiteten och reliabiliteten är att betrakta som hög. Förståelse finns med som en variabel i resultat och diskuteras kort i diskussionen för att försäkra att deltagarna verkligen läst. Den är dock inte avsedd att undersökas i jämförelse med källa och hastighet.Resultatet påvisar en snabbare läshastighet generellt för telefonen (28 opm mer) än i en bok eller telefon. Det visar dock också på att boken vinner över telefonen i två av fem fall och att eleverna som läser på telefonen uppvisar en snabbare läshastighet vid samtliga fall jämfört med en dator. Resultaten är att betrakta som "spretiga" och det går därför inte att utläsa säkra data utifrån dem. Undersökningsgruppen är också att betrakta som liten i sammanhanget.Frågor som ställs och behandlas i diskussionen är om elever lär sig mer om de läser snabbare och om det inte handlar mycket om den enskilda individen och vad han eller hon har för förmågor. Mer förbättringar på mobil och datorområdet och läsning görs och kommer att fortsätta göras och det här arbetet skummar på ämnets yta.Läsning är en komplicerad process som innefattar många faktorer och arbetet har gett upphov till insikt i begreppen förståelse, tolkning av ord och tänkande på en högre nivå som används som definitioner av vad läsning egentligen är. Detta gör det således svårt att forska på området om man inte är väldigt specifik i sin inriktning.
3

SciProvMiner: captura e consulta de proveniência utilizando recursos Web semânticos para ampliação do conhecimento gerado e otimização do processo de coleta

Alves, Tatiane Ornelas Matins 06 September 2013 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-31T14:07:30Z No. of bitstreams: 1 tatianeornelasmartinsalves.pdf: 7124590 bytes, checksum: c53abf20bb1470077226587298efa22d (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-06-01T11:36:48Z (GMT) No. of bitstreams: 1 tatianeornelasmartinsalves.pdf: 7124590 bytes, checksum: c53abf20bb1470077226587298efa22d (MD5) / Made available in DSpace on 2017-06-01T11:36:48Z (GMT). No. of bitstreams: 1 tatianeornelasmartinsalves.pdf: 7124590 bytes, checksum: c53abf20bb1470077226587298efa22d (MD5) Previous issue date: 2013-09-06 / Prover informação histórica de experimentos científicos com o objetivo de tratar o problema de perda de conhecimento do cientista sobre o experimento tem sido o foco de diversas pesquisas. No entanto, o apoio computacional ao experimento científico em larga escala encontra-se ainda incipiente e é considerado um grande desafio. Este trabalho tem o intuito de colaborar para as pesquisas nessa área, apresentando a arquitetura SciProvMiner, cujo principal objetivo é coletar proveniência prospectiva e retrospectiva de experimentos científicos fazendo uso de recursos Web semânticos para otimizar o processo de captura das informações de proveniência e aumentar o conhecimento do cientista sobre o experimento realizado. Como contribuições específicas do SciProvMiner, podemos destacar: - Desenvolvimento de um modelo para contemplar a proveniência prospectiva e retrospectiva como uma extensão do Open Provenance Model (OPM), que em sua forma original modela somente proveniência retrospectiva. - Especificação e implementação de um coletor de proveniência que utiliza a tecnologia de serviços Web para capturar ambos os tipos de proveniência segundo o modelo acima; - Desenvolvimento de uma ontologia denominada OPMO-e, que estende a ontologia Open Provenance Model Ontology (OPMO) de forma a modelar o conhecimento acerca da proveniência prospectiva além da retrospectiva já contemplada na OPMO e onde são implementadas as regras de completude e inferência definidas na documentação do modelo OPM. Estas regras aumentam o conhecimento do cientista sobre o experimento realizado por inferir informações que não foram explicitamente fornecidas pelo usuário e tornando possível a otimização do processo de captura de proveniência e a consequente diminuição do trabalho do cientista para instrumentalizar o workflow; - Especificação de um banco de dados relacional onde são armazenadas as informações de proveniência capturadas pelo coletor, que pode ser utilizado para ser consultado a respeito da proveniência explicitamente capturada, além de fornecer dadosparaas demais funcionalidades do SciProvMiner. / To provide historical scientific information to deal with knowledge loss about scientific experiment has been the focus of several researches. However, the computational support for scientific experiment on a large scale is still incipient and is considered one of the challenges set by the Brazilian Computer Society for 2006 to 2016 period. This work aims to contribute in this area, presenting the SciProvMiner architecture, which main objective is to collect prospective and retrospective provenance of scientific experiments, using ontologies and inference engines to provide useful information in order to increase the knowledge of scientists about a given experiment. We can highlight as specific contributions of SciProvMiner: - Development of a model that encompass prospective and retrospective provenance as an extension of the Open Provenance Model (OPM), which originally onlydeals with retrospective provenance. - Specification and implementation of a provenance collector that uses Web services technology to capture both types of provenance (prospective and retrospective) according to the above model; - Development of an ontology,named Extended OPMO-e, that extends the Open Provenance Model Ontology (OPMO) in order to model prospective provenance beyond the retrospective provenance already covered in OPMO and where are implemented inference and completeness rules defined in OPM documentation. These rules increase the knowledge of scientists on the experiment inferring information that were not explicitly provided by the user and making it possible to optimize the provenance capture mechanism and the consequent decrease on scientist work in order to instrument the workflow. - A relational database specification, where captured provenance information are stored. These information can be used to formulate queries about the provenance explicitly captured, besides provide data to other functionalities of SciProvMiner.
4

Magnétomètres à pompage optique à Hélium 4 : développement et preuve de concept en magnétocardiographie et en magnétoencéphalographie / Helium 4 optically-pumped magnetometers : development and proof of concept in magnetocardiography and magnetoecephalography

Corsi, Marie-Constance 12 October 2015 (has links)
La magnétocardiographie (MCG) et la magnétoencéphalographie (MEG) sont deux techniques d'imagerie non-invasives mesurant respectivement les champs magnétiques cardiaques et cérébraux. Les dispositifs actuels utilisent des capteurs supraconducteurs de haute performance mais nécessitant un dispositif de refroidissement cryogénique, engendrant de fortes contraintes tant techniques que financières. Les magnétomètres à pompage optique (OPM) tendent à constituer une réelle alternative. Parmi eux figurent ceux développés au CEA-LETI, basés sur l'utilisation de l'hélium 4. Cette thèse a pour objectif de développer des magnétomètres vectoriels à 4He (fonctionnant à température ambiante) dédiés aux applications MCG et MEG.Après une optimisation des paramètres-clés d'un prototype non-miniaturisé préexistant, une sensibilité inférieure à 100 fT/sqrt(Hz) a pu être obtenue suivant deux axes. Afin de respecter les besoins spécifiques de la MCG et de la MEG une étape de miniaturisation a dû être menée et une architecture gradient-métrique a été mise en place. Parallèlement, des tests précliniques menés à Clinatec nous ont permis de concevoir un nouveau conditionnement du prototype, ainsi qu'un système réduisant les perturbations magnétiques. Une analyse des principales sources de bruit a révélé que les deux principaux contributeurs au bruit sont le laser et le système de décharge HF. Nous avons ainsi envisagé plusieurs pistes d'amélioration du niveau de bruit dont une nouvelle technique de détection. Le prototype issu de ces travaux comporte une pièce élémentaire (la cellule) d'un centimètre de côté, et présente une sensibilité intrinsèque de 350 fT/sqrt(Hz).Le dispositif a ensuite été testé avec succès dans le cadre de mesures MCG sur un sujet sain, précédées de tests sur fantôme ayant permis de prouver l'opérabilité de nos capteurs dans un environnement clinique. Par ailleurs, la reproductibilité des résultats ainsi que la possibilité de réduire à 30 s le temps d'acquisition des données ont pu être démontrées. Une optimisation spécifique de la partie optique du prototype a permis d'obtenir une sensibilité de l'ordre de 210 fT/sqrt(Hz) entre 3 et 300 Hz, compatible avec l'application MEG. Après des tests menés avec succès sur fantôme, trois séries d'essais ont été réalisées sur un sujet sain. Nous avons pu ainsi détecter des potentiels évoqués auditifs, visuels ainsi qu'une modulation de l'activité cérébrale spontanée sous l'effet de l'ouverture des paupières. L'ensemble des résultats obtenus constitue les premières preuves de concept cliniques du dispositif en MCG et MEG. / Magnetocardiography (MCG) and magnetoencephalography (MEG) are non-invasive techniques consisting in measuring respectively cardiac and brain magnetic fields. Despite their performance, the sensors currently used need a cryogenic cooling system which engenders technical and financial constraints. New cryogenic-free sensors have recently emerged: the OPMs (Optically-Pumped Magnetometers). Among them, vector 4He magnetometers developed by CEA-LETI which work at room-temperature. This thesis is focused on the development of 4He magnetometers dedicated to MCG and MEG.After having optimized the key-parameters of a first non-miniaturized prototype, a sensitivity inferior to 100 fT/sqrt(Hz) has been obtained along two axes. In order to meet biomedical constraints, a miniaturization of the device has been processed. In parallel, preclinical tests were carried out which have enabled us to design a gradiometer mode, a new packaging, and a magnetically isolated system. A noise analysis revealed that laser and HF discharge were the main sources of disturbance, and lead us to consider improvements such as a new detection mode. Eventually, a sensor, with a 1cm-sided cell, and an intrinsic sensitivity of 350 fT/√Hz has been developed.Then, device has been successfully tested in the frame of the MCG application from a healthy subject, preceded by a simulation study with a phantom which enables us to demonstrate its operability within a clinical environment. Moreover, we have proved the reproducibility of the measurements and the possibility to detect the main features of the cardiac cycle within a 30 s recording time. A specific optimization of the optical part has enabled us to obtain a 210 fT/sqrt(Hz) sensitivity between 3 and 300 Hz, suitable for the MEG application. After having tested our device with a phantom, three MEG experiments were performed with a healthy subject: auditory evoked field, visual evoked field and spontaneous activities have been detected. The obtained results form the first clinical proof of concept of the device for MCG and MEG applications.
5

The Construct of Substance Abuse Enabling Applied to Poor Performance Management: How Managers Deal With Poor Performing Employees

Parham, Creda Pamler Joe 29 April 2003 (has links)
The purpose of this study was to examine the attributions and responses that managers make to poor performance using the construct of enabling from the field of substance abuse. Approximately 200 government and 55 non-government managers responded to a three-part questionnaire exploring managers' enabling behaviors, attribution of the causes of poor performance for a current or previous poor performer, and demographics of the managers and their selected poor performing subordinate. The research data showed that there was no appreciable relationship between the managers' demographics and the managers' enabling or non-enabling behaviors toward the poor performer. The data also indicated that managers attribute poor performance to internal attributions instead of external attributions. Furthermore, there was no evidence from the data that attribution played a part in which enabling or non-enabling behavior the managers exhibited toward the poor performer. Analysis of the data showed that managers chose the enabling behavior of micromanaging the poor performer by providing close, daily support; eliminating the employee's responsibilities by extending the deadline; and transferring the problem by transferring the employee to another office. Additionally, some managers indicated that they would reward the poor performance by doing things such as giving ratings commensurate with the norm of the office, before avoiding the poor performance by reducing the requirements of the task. Managers also chose non-enabling behaviors. When combined with enabling behaviors, non-enabling behaviors were the second choice, after micromanaging and before eliminating the employees' responsibilities. The top three non-enabling behaviors used by the managers were giving an oral warning, consulting with management, and giving a written warning. The research not only showed that managers exhibited enabling and non-enabling behaviors towards poor performing employees, it clearly indicated that a continuum of enabling behavior exists. At one end of the continuum are non-enabling behaviors in which managers require poor performers to accept the consequences for their poor performance. At the opposite end of the continuum are behaviors in which managers do not attempt to do anything about either the performance issue or the poor performer. / Ph. D.
6

Estudo de redes ópticas heterogêneas associado à investigação de técnicas avançadas de monitoração de desempenho (OPM) / Networks study optical heterogeneous associated with research advanced techniques for performance monitoring (OPM)

Feres, Mariana Massimino 03 October 2014 (has links)
Os avanços tecnológicos apontam para uma renovação da infraestrutura atual de comunicações ópticas, de modo a torná-la adequada à operação dentro dos novos paradigmas das redes, em que a elasticidade e eficiência espectrais se aliam à alta capacidade de transmissão. Sob o ponto de vista do planejamento de uma operadora de telecomunicação, é desejável que a substituição de equipamentos ocorra de forma mais gradual e que a operação da infraestrutura atual seja otimizada para acomodar a demanda por alta capacidade sem requerer a construção de uma infraestrutura completamente nova. Neste contexto, esta tese investiga estratégias de otimização combinando técnicas que utilizam múltiplas taxas de transmissão (MLR &#8211 Mixed Line Rate) e múltiplos formatos de modulação (MMF &#8211 Multiple Modulation Formats) com foco em um cenário condizente a realidade brasileira, com taxa de transmissão de 10 Gbit/s modulados com a técnica não retorna a zero (NRZ &#8211 non return to zero), migrando para taxa de 40 e/ou 100 Gbit/s. São analisados os benefícios proporcionados com o uso de redes MLR-MMF em comparação com a substituição da rede legada por apenas uma taxa (SLR &#8211 single line rate). A infraestrutura da camada física considerada é uniforme e pode transportar sinais de 10/40/100 Gbit/s, apenas os tipos de transponders são diferentes. Para analisar o desempenho da rede descrita é proposto um modelo de integração entre as ferramentas MatLab e OptiSystem. A primeira é utilizada para definir a rota e a segunda para simular a propagação do sinal óptico na fibra ao longo da rota escolhida. Os valores de taxa de erro de bit (BER &#8211 Bit Error Rate) e a relação sinal ruído óptica (OSNR &#8211 Optical Signal Noise Rate) são armazenados em um banco de dados para uso posterior. Dessa forma diversas topologias podem ser analisadas. Em uma rede real esse tipo de informação pode ser obtido por meio de técnicas de monitoramento óptico (OPM &#8211 Optical Performance Monitoring). Por esse motivo, também são investigados e testados experimentalmente dois métodos de monitoramento da OSNR: i) anulamento da polarização para obter OSNR e ii) monitor multiparâmetro baseado em modulação da polarização em baixa frequência. A partir das análises, concluiu-se que o uso de redes MLR-MMF pode ser uma alternativa para equilibrar o consumo energético e a probabilidade de bloqueio (PB). A opção por esse tipo de rede ajuda na economia energética e mantém a PB em níveis aceitáveis. Além disso, o uso de monitoramento óptico auxilia na obtenção de informações usadas para controlar e gerenciar eficientemente recursos de rede cumprindo os requisitos de qualidade de serviço. / Technological advances point out to an upgrade on the current optical communication infrastructure in order to adequate it to the new networks paradigms, where elasticity and spectral efficiency are associated to the high capacity transmission. From the perspective of a telecom operator planning, it is desirable that the equipment replacement occurs as gradually as possible and that the operation of the current infrastructure is optimized to accommodate the demand for high capacity without requiring the build-upof a completely new infrastructure. In this context, this thesis investigates optimization strategies combining MLR (mixed line rate) and MMF (multiple modulation formats) techniques focusing on a scenario similar to the Brazilian reality, with a transmission rate of 10 Gbit/s NRZ modulated, switching to a rate of 40 and/or 100 Gbit/s. The benefits provided by the use of MMF-MLR network (non return to zero)s compared to the replacing based on a legacy network by only one rate (SLR single line rate) are discussed. The infrastructure of the physical layer is considered uniform and can carry signals 10/40/100 Gbit/s, only the transponder configurations are different. To analyze the network performance we proposed an integration of MATLAB and OptiSystem tools. The first is used to define the route and the second to simulate the propagation of the optical signal in the fiber along the chosen route. The BER and OSNR values are stored in a database for later use. In this way several topologies can be analyzed. In a real network such information may be obtained by optical monitoring techniques (OPM). For this reason, two methods for monitoring OSNR are also investigated: i) the polarization nulling and ii) multiparameter monitor based on modulation of polarization at low frequency. From the analysis it was concluded that the use of MMF-MLR schemes can be an alternative to balance the energy consumption and the blocking probability (BP). The option for this type of network saves energy and helps maintaining BP within acceptable levels. Furthermore, the use of optical monitoring allows the gathering of information used to control and efficiently manage network resources meeting the requirements for quality of service.
7

Estudo de redes ópticas heterogêneas associado à investigação de técnicas avançadas de monitoração de desempenho (OPM) / Networks study optical heterogeneous associated with research advanced techniques for performance monitoring (OPM)

Mariana Massimino Feres 03 October 2014 (has links)
Os avanços tecnológicos apontam para uma renovação da infraestrutura atual de comunicações ópticas, de modo a torná-la adequada à operação dentro dos novos paradigmas das redes, em que a elasticidade e eficiência espectrais se aliam à alta capacidade de transmissão. Sob o ponto de vista do planejamento de uma operadora de telecomunicação, é desejável que a substituição de equipamentos ocorra de forma mais gradual e que a operação da infraestrutura atual seja otimizada para acomodar a demanda por alta capacidade sem requerer a construção de uma infraestrutura completamente nova. Neste contexto, esta tese investiga estratégias de otimização combinando técnicas que utilizam múltiplas taxas de transmissão (MLR &#8211 Mixed Line Rate) e múltiplos formatos de modulação (MMF &#8211 Multiple Modulation Formats) com foco em um cenário condizente a realidade brasileira, com taxa de transmissão de 10 Gbit/s modulados com a técnica não retorna a zero (NRZ &#8211 non return to zero), migrando para taxa de 40 e/ou 100 Gbit/s. São analisados os benefícios proporcionados com o uso de redes MLR-MMF em comparação com a substituição da rede legada por apenas uma taxa (SLR &#8211 single line rate). A infraestrutura da camada física considerada é uniforme e pode transportar sinais de 10/40/100 Gbit/s, apenas os tipos de transponders são diferentes. Para analisar o desempenho da rede descrita é proposto um modelo de integração entre as ferramentas MatLab e OptiSystem. A primeira é utilizada para definir a rota e a segunda para simular a propagação do sinal óptico na fibra ao longo da rota escolhida. Os valores de taxa de erro de bit (BER &#8211 Bit Error Rate) e a relação sinal ruído óptica (OSNR &#8211 Optical Signal Noise Rate) são armazenados em um banco de dados para uso posterior. Dessa forma diversas topologias podem ser analisadas. Em uma rede real esse tipo de informação pode ser obtido por meio de técnicas de monitoramento óptico (OPM &#8211 Optical Performance Monitoring). Por esse motivo, também são investigados e testados experimentalmente dois métodos de monitoramento da OSNR: i) anulamento da polarização para obter OSNR e ii) monitor multiparâmetro baseado em modulação da polarização em baixa frequência. A partir das análises, concluiu-se que o uso de redes MLR-MMF pode ser uma alternativa para equilibrar o consumo energético e a probabilidade de bloqueio (PB). A opção por esse tipo de rede ajuda na economia energética e mantém a PB em níveis aceitáveis. Além disso, o uso de monitoramento óptico auxilia na obtenção de informações usadas para controlar e gerenciar eficientemente recursos de rede cumprindo os requisitos de qualidade de serviço. / Technological advances point out to an upgrade on the current optical communication infrastructure in order to adequate it to the new networks paradigms, where elasticity and spectral efficiency are associated to the high capacity transmission. From the perspective of a telecom operator planning, it is desirable that the equipment replacement occurs as gradually as possible and that the operation of the current infrastructure is optimized to accommodate the demand for high capacity without requiring the build-upof a completely new infrastructure. In this context, this thesis investigates optimization strategies combining MLR (mixed line rate) and MMF (multiple modulation formats) techniques focusing on a scenario similar to the Brazilian reality, with a transmission rate of 10 Gbit/s NRZ modulated, switching to a rate of 40 and/or 100 Gbit/s. The benefits provided by the use of MMF-MLR network (non return to zero)s compared to the replacing based on a legacy network by only one rate (SLR single line rate) are discussed. The infrastructure of the physical layer is considered uniform and can carry signals 10/40/100 Gbit/s, only the transponder configurations are different. To analyze the network performance we proposed an integration of MATLAB and OptiSystem tools. The first is used to define the route and the second to simulate the propagation of the optical signal in the fiber along the chosen route. The BER and OSNR values are stored in a database for later use. In this way several topologies can be analyzed. In a real network such information may be obtained by optical monitoring techniques (OPM). For this reason, two methods for monitoring OSNR are also investigated: i) the polarization nulling and ii) multiparameter monitor based on modulation of polarization at low frequency. From the analysis it was concluded that the use of MMF-MLR schemes can be an alternative to balance the energy consumption and the blocking probability (BP). The option for this type of network saves energy and helps maintaining BP within acceptable levels. Furthermore, the use of optical monitoring allows the gathering of information used to control and efficiently manage network resources meeting the requirements for quality of service.
8

選擇權訂價模式應用於衡量產險公司權益價值及破產機率之硏究

陳俊男, CHEN,JUN-NAN Unknown Date (has links)
本論文乃將財務學上之選擇權訂價模式應用于保險經營方面,其中主要牽涉到理論的 介紹、轉換和應用,全文共分五章: 第一章:結論 其中包括研究背景及動機、研究流程和目的、研究範圍以及全文概述。 第二章:Black-Scholes 選擇權訂價模式 其中包括選擇權之意義、Black-Scholes OPM、BOPM、Compound OPM 及B-S OPM 放寬 假設的情形。 第三章: B-S OPM在產險經營之應用 包括單一期且負責固定下產險公司股價之衡量,逐步擴展到單一期負債變動下產險公 司股價之衡量及考慮多期且加入成本下之衡量,模式內參數之估計,以及產險公司OP M 的經營意義與應用。 第四章:研究設計和結果分析 包括研究假設和限制、研究方法和架構、實質報酬率常態分配之檢定、資料搜集及處 理,以及研究結果和分析。 第五章:結論與建議 包括本文結論與未來研究方向之建議。
9

Enhancing Our Understanding of Human Poverty: An Examination of the Relationship Between Income Poverty and Material Hardship

Bennett, Robert Michael, Jr. 30 October 2017 (has links)
No description available.
10

Contribution au développement d'un prototype de superviseur de performance optique

Obeegadoo, Mervin 12 January 2012 (has links) (PDF)
L'évolution de la nouvelle génération des réseaux optiques vers les réseaux transparents va apporter une flexibilité supplémentaire de la couche physique avec l'adjonction de composants tels que les ROADM (Reconfigurable Add-Drop Multiplexer) et les brasseurs tout optiques. Toutefois, la transparence implique la suppression de nombreuses conversions optique/électrique lors de la transmission d¿un canal. Il devient alors plus difficile de contrôler directement la qualité des signaux numériques en des points intermédiaires du trajet. Pour pallier à ce problème, une solution consiste à recourir aux techniques de surveillance des performances optiques (OPM : Optical Performance Monitoring) qui permettent d'évaluer les caractéristiques des canaux optiques en mesurant certains de leurs paramètres physiques sans mesurer la qualité des signaux numériques transmis par ces canaux. On se focalisera essentiellement sur la mesure du rapport signal à bruit optique (OSNR : Optical Signal-to-Noise Ratio) qui est un paramètre clé dans l'estimation du taux d'erreur binaire. L¿OSNR est mesuré de manière classique par une méthode hors-bande basée sur la méthode d'interpolation linéaire où le bruit au sein du canal est estimé à partir du niveau de bruit présent de part et d'autre du canal. Cependant, cette méthode présente des limitations dans le cas de réseaux de nouvelle génération à base de ROADM où les canaux sont étroitement filtrés. Pour pallier à ce problème, une solution est d'effectuer une mesure intra-bande de l'OSNR qui consiste à évaluer le bruit au sein même du canal en appliquant une technique d'annulation de polarisation à un prototype OPM qui a été conçu au laboratoire.

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