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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.
111

Three-dimensional hydrodynamic models coupled with GIS-based neuro-fuzzy classification for assessing environmental vulnerability of marine cage aquaculture

Navas, Juan Moreno January 2010 (has links)
There is considerable opportunity to develop new modelling techniques within a Geographic Information Systems (GIS) framework for the development of sustainable marine cage culture. However, the spatial data sets are often uncertain and incomplete, therefore new spatial models employing “soft computing” methods such as fuzzy logic may be more suitable. The aim of this study is to develop a model using Neuro-fuzzy techniques in a 3D GIS (Arc View 3.2) to predict coastal environmental vulnerability for Atlantic salmon cage aquaculture. A 3D hydrodynamic model (3DMOHID) coupled to a particle-tracking model is applied to study the circulation patterns, dispersion processes and residence time in Mulroy Bay, Co. Donegal Ireland, an Irish fjard (shallow fjordic system), an area of restricted exchange, geometrically complicated with important aquaculture activities. The hydrodynamic model was calibrated and validated by comparison with sea surface and water flow measurements. The model provided spatial and temporal information on circulation, renewal time, helping to determine the influence of winds on circulation patterns and in particular the assessment of the hydrographic conditions with a strong influence on the management of fish cage culture. The particle-tracking model was used to study the transport and flushing processes. Instantaneous massive releases of particles from key boxes are modelled to analyse the ocean-fjord exchange characteristics and, by emulating discharge from finfish cages, to show the behaviour of waste in terms of water circulation and water exchange. In this study the results from the hydrodynamic model have been incorporated into GIS to provide an easy-to-use graphical user interface for 2D (maps), 3D and temporal visualization (animations), for interrogation of results. v Data on the physical environment and aquaculture suitability were derived from a 3- dimensional hydrodynamic model and GIS for incorporation into the final model framework and included mean and maximum current velocities, current flow quiescence time, water column stratification, sediment granulometry, particulate waste dispersion distance, oxygen depletion, water depth, coastal protection zones, and slope. The Neuro-fuzzy classification model NEFCLASS–J, was used to develop learning algorithms to create the structure (rule base) and the parameters (fuzzy sets) of a fuzzy classifier from a set of classified training data. A total of 42 training sites were sampled using stratified random sampling from the GIS raster data layers, and the vulnerability categories for each were manually classified into four categories based on the opinions of experts with field experience and specific knowledge of the environmental problems investigated. The final products, GIS/based Neuro Fuzzy maps were achieved by combining modeled and real environmental parameters relevant to marine fin fish Aquaculture. Environmental vulnerability models, based on Neuro-fuzzy techniques, showed sensitivity to the membership shapes of the fuzzy sets, the nature of the weightings applied to the model rules, and validation techniques used during the learning and validation process. The accuracy of the final classifier selected was R=85.71%, (estimated error value of ±16.5% from Cross Validation, N=10) with a Kappa coefficient of agreement of 81%. Unclassified cells in the whole spatial domain (of 1623 GIS cells) ranged from 0% to 24.18 %. A statistical comparison between vulnerability scores and a significant product of aquaculture waste (nitrogen concentrations in sediment under the salmon cages) showed that the final model gave a good correlation between predicted environmental vi vulnerability and sediment nitrogen levels, highlighting a number of areas with variable sensitivity to aquaculture. Further evaluation and analysis of the quality of the classification was achieved and the applicability of separability indexes was also studied. The inter-class separability estimations were performed on two different training data sets to assess the difficulty of the class separation problem under investigation. The Neuro-fuzzy classifier for a supervised and hard classification of coastal environmental vulnerability has demonstrated an ability to derive an accurate and reliable classification into areas of different levels of environmental vulnerability using a minimal number of training sets. The output will be an environmental spatial model for application in coastal areas intended to facilitate policy decision and to allow input into wider ranging spatial modelling projects, such as coastal zone management systems and effective environmental management of fish cage aquaculture.
112

Criação e performance musical no contexto dos instrumentos musicais digitais / Music creation and performance in the context of digital musical instruments

Monteiro, Adriano Claro, 1984- 20 August 2018 (has links)
Orientador: Jônatas Manzolli / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Artes / Made available in DSpace on 2018-08-20T07:47:37Z (GMT). No. of bitstreams: 1 Monteiro_AdrianoClaro_M.pdf: 4807040 bytes, checksum: 3fdb8b9f91d66c6551c1e540e753d2ef (MD5) Previous issue date: 2012 / Resumo: Este trabalho apresenta um estudo sobre o computador como instrumento de performance musical. A partir deste estudo desenvolvemos processos de criação musical com base na representação algorítmica e no código computacional. Os dois principais recursos técnicos que utilizamos em nossos trabalhos foram: uma técnica de síntese sonora baseada na geração de forma de ondas por equações não-lineares; e métodos de recuperação de informação musical para prover análise e memória em tempo real dos parâmetros musicais de uma performance. O corpo da dissertação possui a seguinte estrutura: primeiramente, apresentamos as características dos instrumentos musicais digitais e as implicações de seu emprego na prática musical. Em seguida fazemos uma revisão do estado da arte da área de recuperação da informação musical e detalhamos os métodos específicos que utilizamos nesse trabalho, que incluem: a) a extração de parâmetros musicais de sinais de áudio monofônicos capturados de instrumentos acústicos; b) análises do comportamento dinâmico de medidas extraídas do sinal de áudio, através de mapas de Poincaré. Posteriormente, expomos o método de e síntese por equações não-lineares. E por fim, apresentamos os processos de criação musical que desenvolvemos com base nos estudos realizados / Abstract: This work presents a study about the computer as an instrument for musical performance. Based on this study we developed processes of music creation using the algorithmic representation and the computer code. The two main technical resources we applied in our works were: a sound synthesis method based on the generation of waveforms by non-linear equations; and methods for music information retrieval to provide a computer memory of the music parameters in real time. The dissertation has the following structure: first, we show the characteristics of the digital music instruments and the consequences of its using in the musical practice. Second, we review the state of the art of music information retrieval area and we detail the specific methods we used in our works, which include: a) the extraction of music parameters from monophonic audio signals captured from acustic instruments; b) analysis of the dynamic behavior of measurements extracted from audio signal, by means of Poincaré maps. Next, we present the sound synthesis method by non-linear equations. Finally, we show the musical creative process we developed based on our studies / Mestrado / Processos Criativos / Mestre em Música
113

A Framework for Exploring Information Systems Quality Perspectives / Rámec pro posouzení kvalitativních hledisek informačních systémů

Tamtam, Abdurrzzag Giuma A January 2008 (has links)
Záměrem předložené disertační práce je porozumět tomu, jak investoři v konkrétním společenském kontextu vnímají význam kvality informačních systémů. Ze studia literatury zabývající se přístupy a rámci hodnocení kvality informačních systémů vyplývá, že tato kvalita je obecně hodnocena z hlediska striktního přístupu. V této práci je ukázáno, že kvalitu informačního systému lze smysluplně pochopit použitím interpretačního paradigmatu a že kvalita informačního systému je definována společensky a ovlivňována kontextem tohoto systému. Studie byla zahájena průzkumem dvaceti libyjských organizací. Podrobnější data byla získána z případové studie dvou vybraných libyjských organizací působících ve veřejném sektoru. Při empirické analýze nashromážděných dat bylo využito rámce mnohočetné perspektivy, který zahrnuje hlediska teorie strukturalizace, pojem mnohočetných perspektiv a metodologii měkkých systémů. V práci se dospělo ke zjištění, že: a) kvalita informačních systémů je pojata šíře, než je tomu u tradiční definice kvality, b) mnohočetné perspektivy kvality informačních systémů jsou ovlivněny opakovanou interakcí mezi investorem a institucionálními vlastnostmi kontextu informačního systému a že c) rozdílné hodnoty v kulturním prostředí a vnějším kontextu ovlivňují rozsah působnosti investora a interakce v kontextu informačního systému. Ze závěru práce vyplývá, že společenská skladba mnohočetných perspektiv kvality informačního systému je ovlivněna strukturalizačními procesy mezi investory a vlastnostmi v kontextu informačního systému.
114

El Control de gestión en organizaciones sin ánimo de lucro: el caso particular de los colegios de economistas de España

Soldevila García, Pilar 05 July 2000 (has links)
Esta investigación ha identificado los instrumentos de contabilidad de gestión que los gestores de las organizaciones no lucrativas, y más concretamente de los colegios de economistas de España, utilizan y pueden utilizar como sistemas de información para el control de la gestión y para la mejora de su eficiencia, eficacia y economía. Se han realizado tres estudios empíricos: 1. A los gestores de los colegios de economistas, para conocer situación y nivel de implantación de instrumentos de control de gestión .2. Se ha centrado en el análisis de la situación a nivel también de instrumentos de contabilidad de gestión de determinadas asociaciones inglesas que están destinadas a profesionales que ejercen en especialidades que en España pueden realizar los economistas. 3. A usuarios de los colegios, par ver nivel de calidad de los servicios y actividades que los colegios realizan y los efectos de la profesionalidad múltiple que los caracteriza. / It presents the results of a study about management control in non-profit organizations, focusing on the particular case of the Associations of Economists in Spain. In order to do it, a revision of literature and empirical studies have taken place to find out the implementation and level development of the instruments of management accounting in non-profit organizations. The study has been completed with three empirical studies, first directed to Associations of Economists in Spain, the second to associations from the UK related to the economy and the company, and, third directed to users from an Economists'Professional Association. Moreover, interviews of managers of different Associations from the UK have been made.

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