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InVerDa - co-existing Schema Versions Made FoolproofHerrmann, Kai, Voigt, Hannes, Seyschab, Thorsten, Lehner, Wolfgang 01 July 2021 (has links)
In modern software landscapes multiple applications usually share one database as their single point of truth. All these applications will evolve over time by their very nature. Often former versions need to stay available, so database developers find themselves maintaining co-existing schema version of multiple applications in multiple versions. This is highly error-prone and accounts for significant costs in software projects, as developers realize the translation of data accesses between schema versions with hand-written delta code. In this demo, we showcase INVERDA, a tool for integrated, robust, and easy to use database versioning. We rethink the way of specifying the evolution to new schema versions. Using the richer semantics of a descriptive database evolution language, we generate all required artifacts automatically and make database versioning foolproof.
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APLICAÇÃO DE REDES NEURAIS ARTIFICIAIS NO TRATAMENTO DE DADOS AGROMETEOROLÓGICOS VISANDO A CORREÇÃO DE SÉRIES TEMPORAISViecheneski, Rodrigo 24 September 2012 (has links)
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Previous issue date: 2012-09-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This dissertation presents the development of a computational system called System for Treatment of Agrometeorological weather Series (STST Agrometeorológicas), with the objective of treating agrometeorological data in order to correct time weather. For the development of the study some data were collected from the agrometeorological stations, provided by Fundação ABC. The stations were located in the state of Paraná, in the cities of Ponta Grossa (long - 49.95025733, lat - 25.30156819) and Castro (long -49.8672, lat -24.6752). The computational system that has been suggested made use of the technology of Artificial Neural Networks on the type of Multilayer Perceptron and the backpropagation training algorithm of backpropagation error. It was developed with the Object Pascal programming language, using the integrated development environment Embarcadero Delphi 2009. To validate the proposed method we conducted six case studies, and the one which presented the best result for agrometeorological variable average temperature was the first case study of Castro's weather station, with a hit percentage between the treated registers and the registers without failure of 96.5%, a Pearson correlation coefficient of 0.98 and a simple average of the errors obtained from the training the neural network of 0.026406. The average errors of the neural networks was calculated between the values of errors obtained in each training during a period of correction failure. For the agrometeorological variable relative humidity, the best result was found in the case study 5 of Castro’s weather station, with a hit percentage of 95.7%, a Pearson correlation coefficient of 0.97 and the simple average of the errors obtained from the training the neural network of 0,094298. Given this context, it was revealed that the STST Agrometeorological is a viable alternative in the treatment of meteorological variables such as temperature and relative humidity, since there were results with hit percentage greater than 95% in the treatments of fails of the weather series studied. / Esta dissertação apresenta o desenvolvimento de um sistema computacional deno-minado Sistema para Tratamento de Séries Temporais Agrometeorológicas (STST Agrometeorológicas), com o objetivo de tratar dados agrometeorológicos visando a correção de séries temporais. Para o desenvolvimento dos estudos foram utilizados dados de estações agrometeorológicas disponibilizados pela Fundação ABC, situa-da no estado do Paraná, nas cidades de Ponta Grossa (long -49.95025733, lat -25.30156819) e Castro (long -49.8672, lat -24.6752). O sistema computacional pro-posto fez uso da tecnologia de Redes Neurais Artificiais do tipo Perceptron de Múlti-plas Camadas e do algoritmo backpropagation de treinamento de retropropagação do erro. E foi desenvolvido com a linguagem de programação Object Pascal, utili-zando o ambiente de desenvolvimento integrado Embarcadero Delphi 2009. Para validar o método proposto, foram realizados seis estudos de caso, dentre os quais, o que apresentou o melhor resultado para variável agrometeorológica temperatura média foi o estudo de caso 1 da estação agrometeorológica de Castro, com um per-centual de acerto entre os registros tratados e os registros sem falha de 96,5%, um coeficiente de correlação de Pearson de 0,98 e uma média simples entre os erros obtidos nos treinamentos da rede neural de 0,026406. A média dos erros das redes neurais foi calculada entre os valores dos erros obtidos em cada treinamento, duran-te a correção de um determinado período de falha. Para variável agrometeorológica umidade relativa do ar, o melhor resultado encontrado foi o estudo de caso 5 da es-tação agrometeorológica de Castro, com um percentual de acerto de 95,7%, um coe-ficiente de correlação de Pearson de 0,97 e a média simples dos erros da rede neu-ral de 0,094298. Diante desse contexto, foi possível perceber que o STST Agrome-teorológicas é uma alternativa viável no tratamento das variáveis agrometeorológicas temperatura média e umidade relativa do ar, uma vez que, houve resultados com percentual de acerto superior a 95% no tratamento de falhas das séries temporais estudadas.
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Reconhecimento de comandos de voz por redes neuraisRodrigo Jorge Alvarenga 02 June 2012 (has links)
Sistema de reconhecimento de fala tem amplo emprego no universo industrial, no aperfeiçoamento de operações e procedimentos humanos e no setor do entretenimento e recreação. O objetivo específico do trabalho foi conceber e desenvolver um sistema de reconhecimento de voz, capaz de identificar comandos de voz, independentemente do locutor. A finalidade precípua do sistema é controlar movimentos de robôs, com aplicações na indústria e no auxílio de deficientes físicos. Utilizou-se a abordagem da tomada de decisão por meio de uma rede neural treinada com as características distintivas do sinal de fala de 16 locutores. As amostras dos comandos foram coletadas segundo o critério de conveniência (em idade e sexo), a fim de garantir uma maior discriminação entre as características de voz, e assim alcançar a generalização da rede neural utilizada. O préprocessamento consistiu na determinação dos pontos extremos da locução do comando e na
filtragem adaptativa de Wiener. Cada comando de fala foi segmentado em 200 janelas, com superposição de 25% . As features utilizadas foram a taxa de cruzamento de zeros, a energia de curto prazo e os coeficientes ceptrais na escala de frequência mel. Os dois primeiros coeficientes da codificação linear preditiva e o seu erro também foram testados. A rede neural empregada como classificador foi um perceptron multicamadas, treinado pelo algoritmo backpropagation. Várias experimentações foram realizadas para a escolha de limiares, valores práticos, features e configurações da rede neural. Os resultados foram considerados muito bons, alcançando uma taxa de acertos de 89,16%, sob as condições de pior caso da amostragem dos comandos. / Systems for speech recognition have widespread use in the industrial universe, in the improvement of human operations and procedures and in the area of entertainment and recreation. The specific objective of this study was to design and develop a voice recognition system, capable of identifying voice commands, regardless of the speaker. The main purpose of the system is to control movement of robots, with applications in industry and in aid of disabled people. We used the approach of decision making, by means of a neural network trained with the distinctive features of the speech of 16 speakers. The samples of the voice commands were collected under the criterion of convenience (age and sex), to ensure a greater discrimination between the voice characteristics and to reach the generalization of the neural network. Preprocessing consisted in the determination of the endpoints of each command signal and in the adaptive Wiener filtering. Each speech command was segmented into 200 windows with overlapping of 25%. The features used were the zero crossing rate, the short-term energy and the mel-frequency ceptral coefficients. The first two coefficients of the linear predictive coding and its error were also tested. The neural network classifier was a multilayer perceptron, trained by the backpropagation algorithm. Several experiments were performed for the choice of thresholds, practical values, features and neural network configurations. Results were considered very good, reaching an acceptance rate of 89,16%, under the `worst case conditions for the sampling of the commands.
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[pt] MODELAGEM DAS PROPRIEDADES DO TIO2 NA PREVISÃO DO BAND GAP UTILIZANDO REDES NEURAIS ARTIFICIAIS / [en] MODELLING OF TIO2 PROPERTIES FOR THE BAND GAP PREDICTION USING ARTIFICIAL NEURAL NETWORKSANNITA DA COSTA FIDALGO 28 December 2020 (has links)
[pt] O dióxido de titânio é amplamente utilizado pela indústria e pesquisa como
fotocatalisador, cuja principal desvantagem ainda é sua aplicação sob luz
visível. Propriedades como quantidade de fases, tamanho do cristalito, área
de superfície específica, volume de poros e valor da banda proibida (Eg)
são explorados por métodos de síntes e para aprimorar a performance do
TiO2. No entanto, elas são ajustadas empiracamente. O presente trabalho
foi realizado a fim de descrever uma relação analítica entre essas propriedades para a fotocatálise, usando Redes Neurais Artificiais (RNAs) como
ferramente estatística. Afim de ter o banco de dados mais representativo,
foram usados 53 artigos. O Eg foi considerado a medida a qual avalia a performance fotocatalítica, sendo o parâmetro de saída da rede. Dois blocos A
e B, distintos pelas variáveis de entrada, foram arranjados em grupos para
investigar a influência das variáveis em pares, com 257 e 220 fotocatalisadores para cada, respectivamente. Exploraram-se diferentes algoritmos de
treinamento (baseados em Retropropagação), tipos de redes (Feedforward,
Cascade forward e Elman), funções de transferência, número de neurônios
e redemulticamadas. Avaliaram-se os modelos pela Soma dos Erros Quadráticos (SSE),pelo coeficiente de correlação de regressão (R2) tanto para
o treinamento e quanto para o teste, pelo comportamento de predição do
banco de dados e pelo diagrama de regressão dos valores preditos pelos observados. Os resultados do bloco A sugerem que as variáveis não aparentam
ter uma relação. Os modelos de múltiplas camadas no bloco B revelaram um
aumento no desempenho. O resultado de maior coeficiente teve topologia
de 4-4-6-1, correspondendo a camada de entrada, primeira camada oculta,
segunda camada oculta e camda de saída, respectivamente. Obteve-se R2
de 84 por cento para o treinamento e 50 por cento para o teste, com SSE de 2.24.Esse
resultado sugere que a rede não é capaz de prever o Eg, mas ela pode ser
aprimorada. Os parâmetros estruturais devem ser revisados, de acordo com
padrões de caracterizações e dados estatísticos. Consequentemente, o modelo pode ser bem ajustado, otimizado e usado na melhoria da fotocatálise. / [en] Titanium dioxide has been widely applied by industry and scientific research
as a photocatalyst,whose main drawback still has been the application under visible light.Properties such as phases amount,crystallite size, specific
surface area, pore volume, and band gap value (Eg)have been explored by
synthesis methods to improve TiO2 s performance. However, they are empirically adjusted.The present work was carried out to describe an analytical
relation between those properties for photocatalysis, using Artificial Neural Networks (ANNs) as a statistical tool. Aiming the most representative
set, 53 literature papers were used for the database. Eg was considered the
measurement which evaluates the photocatalytic performance, namely the
network s out put variable. Two blocks A and B, which are distinguished by
input variables, were arranged into groups to investigate the variables pair
influences, using 257 and 220 photocatalysts vectors for each,respectively.
Modelling attempts examined different training algorithms(based on Back-
propagation), types of networks (Feedforward, Cascade forward and Elman),
transfer functions, number of hidden neurons, and multilayer network.The
developedmodelswereevaluatedbythesumofsquarederror(SSE),the
correlation coefficient(R2) of regression for both training and test data,
the prediction behaviour of the dataset,and the regression diagram of predicted and observed values. The block A results suggest the variables do
not have an apparent relationship. Multilayers models on block B revealed an increase of network identification performance. The result with the
highest coefficient showed 4-4-6-1 topology; corresponding, respectively, to
input, first hidden, second hidden and output layers.It had R2 of 84 percent for
training and to 50 percent fortest, with SSE of 2.24.This result suggests this
network is not able topredict the Eg, but it can be improved. The structural
properties should be reviewed, according to standards of characterization
and statistical data. Hence, the model could be well fitted, optimized, and
used for photocatalysis improvement.
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Predicting corporate credit ratings using neural network modelsFrank, Simon James 12 1900 (has links)
Thesis (MBA (Business Management))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: For many organisations who wish to sell their debt, or investors who are looking to invest in an organisation, company credit ratings are an important surrogate measure for the
marketability or risk associated with a particular issue. Credit ratings are issued by a limited number of authorised companies – with the predominant being Standard & Poor’s, Moody’s
and Fitch – who have the necessary experience, skills and motive to calculate an objective
credit rating. In the wake of some high profile bankruptcies, there has been recent conjecture about the accuracy and reliability of current ratings. Issues relating specifically to the lack of competition in the rating market have been identified as possible causes of the poor
timeliness of rating updates. Furthermore, the cost of obtaining (or updating) a rating from
one of the predominant agencies has also been identified as a contributing factor. The high
costs can lead to a conflict of interest where rating agencies are obliged to issue more
favourable ratings to ensure continued patronage.
Based on these issues, there is sufficient motive to create more cost effective alternatives to
predicting corporate credit ratings. It is not the intention of these alternatives to replace the
relevancy of existing rating agencies, but rather to make the information more accessible,
increase competition, and hold the agencies more accountable for their ratings through better
transparency. The alternative method investigated in this report is the use of a backpropagation artificial neural network to predict corporate credit ratings for companies in the manufacturing sector of the United States of America. Past research has shown that backpropagation neural
networks are effective machine learning techniques for predicting credit ratings because no prior subjective or expert knowledge, or assumptions on model structure, are required to
create a representative model. For the purposes of this study only public information and
data is used to develop a cost effective and accessible model. The basis of the research is the assumption that all information (both quantitive and qualitative) that is required to calculate a credit rating for a company, is contained within financial data from income statements, balance sheets and cash flow statements. The premise of the assumption is that any qualitative or subjective assessment about company creditworthiness will ultimately be reflected through financial performance. The results show that a backpropagation neural network, using 10 input variables on a data
set of 153 companies, can classify 75% of the ratings accurately. The results also show that
including collinear inputs to the model can affect the classification accuracy and prediction
variance of the model. It is also shown that latent projection techniques, such as partial least squares, can be used to reduce the dimensionality of the model without making any
assumption about data relevancy. The output of these models, however, does not improve
the classification accuracy achieved using selected un-correlated inputs. / AFRIKAANSE OPSOMMING: Vir baie organisasies wat skuldbriewe wil verkoop, of beleggers wat in ʼn onderneming wil belê is ʼn maatskappy kredietgradering ’n belangrike plaasvervangende maatstaf vir die bemarkbaarheid van, of die risiko geassosieer met ʼn betrokke uitgifte. Kredietgraderings word deur ʼn beperkte aantal gekeurde maatskappye uitgereik – met die belangrikste synde Standard & Poor’s, Moody’s en Fitch. Hulle het almal die nodige ervaring, kundigheid en rede om objektiewe kredietgraderings te bereken. In die nadraai van ʼn aantal hoë profiel bankrotskappe was daar onlangs gissings oor die akkuraatheid en betroubaarheid van huidige graderings. Kwessies wat spesifiek verband hou met die gebrek aan kompetisie in die graderingsmark is geïdentifiseer as ‘n moontlike oorsaak vir die swak tydigheid van gradering opdatering. Verder word die koste om ‘n gradering (of opdatering van gradering) van een van die dominante agentskappe te bekom ook geïdentifiseer as ʼn verdere bydraende faktor gesien. Die hoë koste kan tot ‘n belange konflik lei as graderingsagentskappe onder druk kom om gunstige graderings uit te reik om sodoende volhoubare klante te behou. As gevolg van hierdie kwessies is daar voldoende motivering om meer koste doeltreffende alternatiewe vir die skatting van korporatiewe kredietgraderings te ondersoek. Dit is nie die doelwit van hierdie alternatiewe om die toepaslikheid van bestaande graderingsagentskappe te vervang nie, maar eerder om die inligting meer toeganklik te maak, mededinging te verhoog en om die agentskappe meer toerekenbaar vir hul graderings te maak deur beter
deursigtigheid. Die alternatiewe manier wat in hierdie verslag ondersoek word, is die gebruik van ‘n kunsmatige neurale netwerk om die kredietgraderings van vervaardigingsmaatskappye in die VSA te skat. Vorige navorsing het getoon dat neurale netwerke doeltreffende masjienleer
tegnieke is om kredietgraderings te skat omdat geen voorafkennis of gesaghebbende kundigheid, of aannames oor die modelstruktuur nodig is om ‘n verteenwoordigende model te bou. Vir doeleindes van hierdie navorsingsverslag word slegs openbare inligting en data gebruik om ʼn kostedoeltreffende en toeganklike model te bou. Die grondslag van hierdie navorsing is die aanname dat alle inligting (beide kwantitatief en
kwalitatief) wat benodig word om ʼn kredietgradering vir ʼn onderneming te bereken, opgesluit is in die finansiële data in die inkomstestate, balansstate en kontantvloei state. Die aanname is dus dat alle kwalitatiewe of subjektiewe assessering oor ‘n maatskappy se
kredietwaardigheid uiteindelik in die finansiële prestasie sal reflekteer. Die resultate toon dat ʼn neurale netwerk met 10 toevoer veranderlikes op ‘n datastel van 153 maatskappye 75% van die graderings akkuraat klassifiseer. Die resultate toon ook dat die insluiting van kollineêre toevoere tot die model die klassifikasie akkuraatheid en die variansie van die skatting kan beïnvloed. Daar word verder getoon dat latente projeksietegnieke, soos parsiële kleinste kwadrate, die dimensies van die model kan verminder sonder om enige aannames oor data toepaslikheid te maak. Die afvoer van hierdie modelle verhoog egter nie die klassifikasie akkuraatheid wat behaal is met die gekose ongekorreleerde toevoere nie. 121 pages.
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Kombination av exempelbaserad och belöningsbaserad inlärning för ANN / Combination of supervised and unsupervised learning of ANNPogemaa, Joel January 2019 (has links)
Det här experimentet gick ut på att testa tre olika inlärningsstrategier emot varandra i en spelmiljö. De tre inlärningsstrategier som testades var en exempelbaserad strategi, en belöningsbaserad strategi och en strategi som kombinerade dessa två algoritmer. Kombinationen bestod av att först träna upp ett nätverk med den exempelbaserade strategin för att sedan använda det nätverket som en utgångspunkt för den belöningsbaserade strategin. Dessa strategier testades sedan i en spelmiljö. Resultatet som de olika strategierna producerade var svårtolkade. På grund av att alla inlärningsstrategierna inte förbättrade sig märkvärdigt under deras träningstid har det gjort att resultaten från att ändra på variablerna hos de olika strategierna inte visat på några märkvärda skillnader i resultat. Skillnader i resultat vid jämförelser av de olika strategierna har observerats men det går inte att säkerställa att det är inlärningsstrategierna som är anledningen till skillnad i resultat.
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Neural Networks and the Natural GradientBastian, Michael R. 01 May 2010 (has links)
Neural network training algorithms have always suffered from the problem of local minima. The advent of natural gradient algorithms promised to overcome this shortcoming by finding better local minima. However, they require additional training parameters and computational overhead. By using a new formulation for the natural gradient, an algorithm is described that uses less memory and processing time than previous algorithms with comparable performance.
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Neural Network Gaze Tracking using Web CameraBäck, David January 2006 (has links)
<p>Gaze tracking means to detect and follow the direction in which a person looks. This can be used in for instance human-computer interaction. Most existing systems illuminate the eye with IR-light, possibly damaging the eye. The motivation of this thesis is to develop a truly non-intrusive gaze tracking system, using only a digital camera, e.g. a web camera.</p><p>The approach is to detect and track different facial features, using varying image analysis techniques. These features will serve as inputs to a neural net, which will be trained with a set of predetermined gaze tracking series. The output is coordinates on the screen.</p><p>The evaluation is done with a measure of accuracy and the result is an average angular deviation of two to four degrees, depending on the quality of the image sequence. To get better and more robust results, a higher image quality from the digital camera is needed.</p>
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Applications of Data Mining on Drug Safety: Predicting Proper Dosage of Vancomycin for Patients with Renal Insufficiency and ImpairmentYon, Chuen-huei 24 August 2004 (has links)
Abstract
Drug misuses result in medical resource wastes and significant society costs. Due to the narrow therapeutic range of vancomycin, appropriate vancomycin dosage is difficult to determine. When inappropriate dosage is used, such side effects as poisoning reaction or drug resistance may occur. Clinically, medical professionals adjust drug protocols of vancomycin based on the Therapeutic Drug Monitoring (TDM) results. TDM is usually defined as the clinical use of drug blood concentration measurements as an aid in dosage finding and adjustment. However, TDM cannot be applied to first-time treatments and, in case, dosage decisions need to reply on medical professionals¡¦ clinical experiences and judgments.
Data mining has been applied in various medical and healthcare applications. In this study, we will employ a decision-tree induction (specifically, C4.5) and a backpropagation neural network technique for predicting the appropriateness of vancomycin usage for patients with renal insufficiency and impairment. In addition, we will evaluate whether the use of the boosting and bagging algorithms will improve predictive accuracy.
Our empirical evaluation results suggest that use of the boosting and bagging algorithms could improve predictive accuracy. Specifically, use of C4.5 in conjunction with the AdaBoost algorithm achieves an overall accuracy of 79.65%, which significantly improves that of the existing practice, recording an accuracy rate at 41.38%. With respect to the appropriateness category (¡§Y¡¨) and the inappropriateness category (¡§N¡¨), C4.5 in conjunction with the AdaBoost algorithm can achieve a recall rate at 78.75% and 80.25%, respectively. Hence, the incorporation of data mining techniques to decision support would enhance the drug safety, which in turn, would improve patient safety and reduce subsequent medical resource wastes.
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Prediction of Coke Quality in Ironmaking Process: A Data Mining ApproachHsieh, Hsu-huang 28 August 2006 (has links)
Coke is an indispensable material in Ironmaking process by blast furnace. To provide good and constant quality coke for stable and efficient blast furance operation is very important. Furthermore, a challenging issue in the cokemaking process is the prediction of coke quality. An accurate prediction can support production planning decision and reduce business operation costs.
The objective of this thesis is to apply the backpropagation neural network and the model tree techniques for predicting the strength and meansize of coke. Specifically, we developed the coke- physical&chemical-property model, coal-usage model, coal-group-usage model, and extended model for the target prediction task. Experimentally, we found that the coal-usage model achieves the highest Correlation Coefficient and the lowest Mean Absolute Error. Moreover, the model trees technique reaches higher accuracy and better efficiency than does the backpropagation neural network technique.
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