Study and optimization of the memory management in Memcached

Over the years the Internet has become more popular than ever and web applications like Facebook and Twitter are gaining more users. This results in generation of more and more data by the users which has to be efficiently managed, because access speed is an important factor nowadays, a user will not wait no more than three seconds for a web page to load before abandoning the site. In-memory key-value stores like Memcached and Redis are used to speed up web applications by speeding up access to the data by decreasing the number of accesses to the slower data storage’s. The first implementation of Memcached, in the LiveJournal’s website, showed that by using 28 instances of Memcached on ten unique hosts, caching the most popular 30GB of data can achieve a hit rate around 92%, reducing the number of accesses to the database and reducing the response time considerably. Not all objects in cache take the same time to recompute, so this research is going to study and present a new cost aware memory management that is easy to integrate in a key-value store, with this approach being implemented in Memcached. The new memory management and cache will give some priority to key-value pairs that take longer to be recomputed. Instead of replacing Memcached’s replacement structure and its policy, we simply add a new segment in each structure that is capable of storing the more costly key-value pairs. Apart from this new segment in each replacement structure, we created a new dynamic cost-aware rebalancing policy in Memcached, giving more memory to store more costly key-value pairs. With the implementations of our approaches, we were able to offer a prototype that can be used to research the cost on the caching systems performance. In addition, we were able to improve in certain scenarios the access latency of the user and the total recomputation cost of the key-value stored in the system

Automatic classifier of scientific contents

The growth of scientific production, associated with the increase in the complexity of scientific contents, makes the classification of these contents highly subjective and subject to misinterpretation. The taxonomy on which this classification process is based does not follow the scientific areas' changes. These classification processes are manually carried out and are therefore subject to misclassification. A classification process that allows automation and implements intelligent algorithms based on Machine Learning algorithms presents a possible solution to subjectivity in classification. Although it does not solve the inadequacy of taxonomy, this work shows this possibility by developing a solution to this problem. In conclusion, this work proposes a solution to classify scientific content based on the title, abstract, and keywords through Natural Language Processing techniques and Machine Learning algorithms to organize scientific content in scientific domains.This work has been supported by IViSSEM: POCI-01-0145-FEDER-28284

Machine learning and natural language processing in domain classification of scientific knowledge objects: a review

The domain classification of scientific knowledge objects has been continuously improved over the years. Systems that can automatically classify a scientific knowledge object, through the use of artificial intelligence, machine learning algorithms, natural language processing, and others, have been adopted in most scientific knowledge databases to maintain internal classification consistency as well as to simplify the information arrangement. However, the amount of available data has grown exponentially in the last few years and now it can be found in multiple platforms under different classifications due to the implementation of different classification systems. Thus, the process of searching and selecting relevant data in research studies and projects has become more complex and the time needed to find the right information has continuously grown as well. Therefore, machine learning and natural language processing play an important role in the development and achievement of automatic and standardized classification systems that will aid researchers in their research work.This work has been supported by IViSSEM: POCI-01-0145-FEDER-28284

A Field Analysis of Relational Database Schemas in Open-source Software (Extended)

International audienceThe relational schemas of 512 open-source projects storing their data in MySQL or PostgreSQL databases are investigated by querying the standard information schema, looking for various issues. These SQL queries are released as the Salix free software. As it is fully relational and relies on standards, it may be installed in any compliant database to help improve schemas. The overall quality of the surveyed schemas is poor: a majority of projects have at least one table without any primary key or unique constraint to identify a tuple; data security features such as referential integrity or transactional back-ends are hardly used; projects that advertise supporting both databases often have missing tables or attributes. PostgreSQL projects have a better quality compared to MySQL projects, and it is even better for projects with PostgreSQL-only support. However, the difference between both databases is mostly due to MySQL-specific issues. An overall predictor of bad database quality is that a project chooses MySQL or PHP, while good design is found with PostgreSQL and Java. The few declared constraints allow to detect latent bugs, that are worth fixing: more declarations would certainly help unveil more bugs. Our survey also suggests some features of MySQL and PostgreSQL as particularly error-prone. This first survey on the quality of relational schemas in open-source software provides a unique insight in the data engineering practice of these project

On the Quality of Relational Database Schemas in Open-source Software

International audienceThe relational schemas of 512 open-source projects storing their data in MySQL or PostgreSQL databases are investigated by querying the standard information schema, looking for overall design issues. The set of SQL queries used in our research is released as the Salix free software. As it is fully relational and relies on standards, it may be installed in any compliant database to help improve schemas. Our research shows that the overall quality of the surveyed schemas is poor: a majority of projects have at least one table without any primary key or unique constraint to identify a tuple; data security features such as referential integrity or transactional back-ends are hardly used; projects that advertise supporting both databases often have missing tables or attributes. PostgreSQL projects appear to be of higher quality than MySQL projects, and have been updated more recently, suggesting a more active maintenance. This is even better for projects with PostgreSQL-only support. However, the quality difference between both databases management systems is mostly due to MySQL-specific issues. An overall predictor of bad database quality is that a project chooses MySQL or PHP, while good design is found with PostgreSQL and Java. The few declared constraints allow to detect latent bugs, that are worth fixing: more declarations would certainly help unveil more bugs. Our survey also suggests that some features of MySQL and PostgreSQL are particularly error-prone. This first survey on the quality of relational schemas in open-source software provides a unique insight in the data engineering practice of these projects

Análise das relações entre a transparência e a acurácia orçamentária nos estados brasileiros

This work sought to analyze the relationship between budgetary accuracy and public transparency of Brazilian state governments. It aimed to identify whether transparency influences an effective collection of expected revenues, as well as to analyze their forecasting efficiency. The initial assumption was that the higher the levels of transparency, the better the budgetary accuracy of the states. In the theoretical framework, the Public Budget, its main types and its elaboration and transparency were discussed. To carry out the research, the documentary technique was used, where content from the transparency sites of the 26 states and the federal district was analyzed. Pearson's correlation test was used to analyze the variables. Empirical evidence indicates that the states that are part of the south, southeast and midwest regions of Brazil have better results in their indicators in the variables of transparency, GDP per capita and competitiveness of the states, in contrast the states of the north and northeast regions the worst indexes. It can be seen in the results of the correlations that there is no association between the indicators of levels of transparency and budgetary accuracy observed in the Brazilian states in the analyzed period.Esse trabalho buscou analisar as relações entre a acurácia orçamentária e a transparência pública dos governos estaduais brasileiros. Teve como objetivo identificar se a transparência influência numa efetiva arrecadação de receitas previstas, bem como analisar a eficiência de previsão das mesmas. O pressuposto inicial era que quanto maior fossem os níveis de transparência, melhor seria a acurácia orçamentária dos estados. No referencial teórico foram discorridos sobre o Orçamento Público, seus principais tipos e sua elaboração e a transparência. Para a realização da pesquisa foi utilizada a técnica documental, onde foi analisado conteúdo dos sites de transparência dos 26 estados e o distrito federal. Utilizou-se o teste estatístico de correlação de Pearson para análise das variáveis. As evidências empíricas apontam que os estados que fazem parte regiões sul, sudeste e centro oeste do Brasil possuem melhores resultados em seus indicies nas variáveis de transparência, PIB per capita e competitividade dos estados, em contrapartida os estados das regiões norte e nordeste apresentaram os piores índices. Verificou-se nos resultados das correlações que não existe associação entre os indicadores de níveis de transparência e acurácia orçamentária observadas nos estados brasileiros no período analisado

Análise de proteínas nucleares reguladas na amastigogênese e de complexos proteicos de Trypanosoma Cruzi

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Biologia Celular, 2013.Uma característica do Trypanosoma cruzi são as mudanças morfológicas que ocorrem durante seu ciclo de vida. A amastigogênese é um importante processo no ciclo de vida do parasita onde as formas tripomastigotas infectivas se diferenciam em amastigotas replicativas. A duplicação celular é um processo complexo, onde vários eventos estão envolvidos, dentre eles, a correta segregação das cromátides irmãs após a replicação do DNA, função exercida por um complexo denominado coesina. Neste trabalho, foi proposta caracterização de complexos proteicos de T.cruzi assim como a identificação de proteínas de complexos nucleares, cuja expressão se altera durante a amastigogênese. Por meio da técnica Blue Native PAGE (BN-PAGE) foi possível realizar a separação de complexos proteicos de lisado total das formas epimastigotas de Trypanosoma cruzi. Os componentes individuais dos complexos puderam ser visualizados em segunda dimensão após o gel ter sido corado com nitrato de prata. Experimentos de detecção imunológica por western blotting demonstraram a ausência da subunidade SCC1 do complexo coesina em amastigotas gerados por diferenciação in vitro de formas tripomastigotas em cultura axênica em pH 5. Porém, a subunidade SCC1 pode ser detectada em extratos proteicos de formas amastigotas que foram reincubadas por 10 h em meio de cultura com pH ajustado para 7,5, sugerindo que essas formas são capazes de manter suas propriedades replicativas. Por espectrometria de massas do tipo LC-MS/MS, 1.339 proteínas de T. cruzi foram identificadas de amostras provenientes dos ensaios de amastigogênese. Destas, 560 proteínas foram anotadas em bancos de dados como proteínas reguladas, 65 possuíam localização nuclear e 66 foram preditas como pertencentes a complexos proteicos. Na classificação das proteínas identificadas os grupos que correspondem àqueles envolvidos em metabolismo de ácidos nucleicos aparecem como predominantes. Proteínas que se ligam a DNA (9,23%), proteínas de ligação a RNA (13,85%) e proteínas que se ligam a nucleotídeos (18,46%) correspondem juntas a 41,54% do total de proteínas nucleares reguladas, corroborando o fato de que intensa atividade de transcrição e processamento de DNA e RNA ocorre em todas as etapas de diferenciação, além de outros principais grupos como as peptidases (15,38%), proteínas estruturais (13,85%) e atividade de hidrolases (12,31%). Para proteínas reguladas e envolvidas com complexos proteicos durante a amastigogênese os maiores grupos estão envolvidos em processos de transporte (25,58%), processos metabólicos (19,77%), processos metabólicos de compostos contendo nucleotídeos (16,28%), geração de precursores metabólicos e de energia (8,14%). ______________________________________________________________________________ ABSTRACTA feature of Trypanosoma cruzi is the morphological changes that occur during their life cycle. The amastigogenesisis an important process in the life cycle of the parasite where the infective trypomastigotes differentiate into replicative amastigotes. A cell replication is a complex process, where several events are involved, among them the correct segregation of sister chromatids after DNA replication, function performed by a complex called cohesin. In this work we proposed the characterization of T. cruzi protein complexes and the identification of proteins from nuclear complexes, whose expression is altered during amastigogenesis. Through the technique of Blue Native PAGE (BN-PAGE) it was possible the separation of protein complexes from total lysate of T. cruzi epimastigotes. The individual components of the complexes could be visualized after the second dimensional gel after stainingwith silver nitrate. Immunological detection experiments by western blotting demonstrated the absence of SCC1 subunit of cohesin complex in amastigotes generated by in vitro differentiation of trypomastigotes in axenic culture at pH 5.0. However, the subunit SCC1 was detected in protein extracts of amastigotes that were reincubated for 10 hours in a culture medium adjusted at pH 7.5, suggesting that these forms are able to maintain their replicative properties. By LC-MS/MS mass spectrometry, 1,339 proteins ofT.cruzi were identified in samples from mastigogenesis. Of these, 560 proteins were annotated in databases as regulated proteins, 65 have presented nuclear localization and 66 were predicted as belonging to protein complexes. In the classification of proteins involved in nucleic acid metabolism, this group appears to be predominant. Proteins which bind to DNA (9.23%), RNA-binding proteins (13.85%) and proteins that bind nucleotides (18.46%) correspond together to 41.54% of the total regulated nuclear proteins, confirming that strong transcription activity and DNA and RNA processing occur in all stages of differentiation, and other major groups such as peptidases (15.38%), structural proteins (13.85%) and activity of hydrolases (12.31%). For regulated proteins and protein complexes involved in amastigogenesis the largest groups are involved in transport processes (25.58%), metabolic processes (19.77%), metabolic processes of compounds containing nucleotides (16.28%), generation of metabolic precursors and energy (8.14%)

Controlo directo de binário de uma máquina assíncrona trifásica

Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica Ramo de Automação e Electrónica IndustrialEsta dissertação de Mestrado foi realizada com o objectivo de se efectuar o estudo teórico e a sua comprovação, por simulação e ensaios experimentais, do Controlo Directo de Binário – DTC para uma máquina assíncrona trifásica, que é uma das muitas técnicas utilizadas no Controlo Vectorial. Numa primeira fase foi efectuado o estudo teórico e modelização da máquina assíncrona trifásica, do conversor estático de potência (funcionamento como ondulador de tensão trifásico) e da técnica do Controlo Directo de Binário – DTC. No Controlo Directo de Binário podem ser utilizadas várias técnicas de comutação, que irão corresponder a um diferente desempenho dinâmico sobre o binário e sobre o fluxo estatórico. Nesta dissertação foi efectuado o estudo de duas das várias técnicas de comutação que a técnica do Controlo Directo de Binário contempla, nomeadamente, as duas técnicas que utilizam o funcionamento nos quatro quadrantes. A diferença entre as duas técnicas estudadas reside na utilização e na não utilização de vectores de tensão nulos. No estudo teórico foram efectuadas transformações de referenciais com o objectivo de realizar a implementação na simulação numérica dos vários blocos que constituem o modelo global. Com a implementação do modelo global na simulação numérica, foram realizadas diversas simulações numéricas, quer em regime estacionário quer em regime dinâmico, inicialmente em malha aberta e posteriormente em malha fechada. Em malha fechada, com a utilização de um anel exterior, foi realizado o controlo de velocidade com o projecto e dimensionamento do compensador PI (proporcional e integral). A implementação laboratorial do protótipo foi constituída pelo rectificador de tensão trifásico, que funciona com as tensões nominais da rede (400Vac) e pelo ondulador de tensão trifásico, onde foi utilizado um módulo compacto de IGBTs, constituído pelos seis semicondutores de potência e pelos respectivos circuitos de guiamento de ajuda à comutação e protecção. Como carga foi utilizada a máquina assíncrona trifásica. O Controlo Directo de Binário – DTC e o anel exterior para controlo da velocidade foram implementados num controlador digital do fabricante dSPACE. Com esta implementação foram realizados diversos ensaios laboratoriais, nas mesmas condições aos realizados na simulação numérica e assim, permitindo efectuar a comparação e análise dos respectivos resultados.Abstract: This Master’s thesis was undertaken with the aim to make the theoretical study and its verification by simulation and experimental tests, the Direct Torque Control - DTC for a three-phase asynchronous machine, which is one of many techniques used in Vector Control. In the first phase was carried out theoretical study and modeling of three-phase asynchronous machine, the static power converter (inverter operation as three-phase voltage) and the technique of Direct Torque Control - DTC. In the Direct Torque Control can be used several switching techniques that will correspond to a different dynamic performance of the torque and the stator flux. This dissertation was carried out to study two different switching techniques of the technique of direct control of the torque comprises, in particular, both techniques that use four-quadrant operation. The difference between both techniques is the use and non-use of zero voltage vectors. In the theoretical study were made transformations of references in order to carry out the implementation in the numerical simulation of the various blocks that constitute the global model. With the implementation of the global model in numerical simulation, several numerical simulations were carried out either in steady regime or in dynamic regime, initially in open loop and in closed loop later. In closed loop with the use of an outer ring, was performed with speed control compensator with a design and dimensioning compensator PI (proportional and integral). The implementation laboratory prototype was made by rectifier three-phase voltage, which works with nominal voltages of the network (400Vac) and the inverter voltage phase, where we used a compact module IGBTs, consists of the six power semiconductors and the respective circuits guiding help to switching and protection. Was used as loading three-phase asynchronous machine. The Direct Torque Control - DTC and the outer ring for speed control have been implemented in a digital controller manufacturer dSPACE. With this implementation have been several laboratory tests, performed under the same conditions for the numerical simulation and thus permitting the comparison and analysis of their results

Estrutura oligomérica e dinâmica de Major Royal Jelly Protein 1 (MRJP1)/apisimina analisadas por espectrometria de massas e técnicas complementares

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Biologia Celular, Pós-Graduação em Biologia Molecular, 2017.Geleia Real (GR) dispara o desenvolvimento de larvas de abelhas fêmeas até rainhas. Este efeito tem sido atribuído à presença de Major Royal Jelly Protein 1 (MRJP1) presente na geleia real. MRJP1 isolada de GR está intimamente associada a apisimina, um peptídeo helicoidal com 54 resíduos de aminoácidos que promove uma associação não covalente de MRJP1 em oligômeros de diferentes tamanhos. Não existem dados de alta resolução disponíveis para essas estruturas e até mesmo sua estequiometria ainda não é clara. Nesta tese, examinamos a relação MRJP1/apisimina usando um arsenal de técnicas biofísicas. Também, investigamos o comportamento de MRJP1/apisimina em amostras após remoção de seus carboidratos e de apisimina associada. Nossos dados de espectrometria de massas (MS) nativos demonstraram que os complexos existem predominantemente numa estequiometria de MRJP14/apisimina4. Blue native PAGE demonstrou a prevalência de estruturas tetraméricas e monoméricas. Microscopia de força atômica demonstrou a presença de populações que puderam ser agrupadas em dois grandes grupos. Troca do hidrogênio por deutério (HDX) seguida de análises por espectrometria de massas revelaram que MRJP1, nesses complexos, é desordenada na extensão dos resíduos 20-265. Estruturas secundárias (provavelmente folhas beta antiparalelas) estáveis são encontradas marginalmente ao redor dos resíduos 266-432. Estas são regiões fracamente estruturadas com conformações que variam entre estruturada e desestruturada, gerando uma distribuição isotópica bimodal (EX1). Nós propomos que os complexos nativos (tetrâmeros) têm uma estrutura quaternária formada por “dímero de dímero”, onde as cadeias de MRJP1 são ligadas por apisimina. Especificamente, nossos dados sugerem que apisimina age como um ligante que forma contatos hidrofóbicos envolvendo o segmento 316VLFFGLV322 de MRJP1. Esta proteína tem dois sítios de glicosilação localizados nos resíduos de aminoácidos 144 e 177. Por 2DE podemos ver 9 proteoformas de MRJP1, mesmo após a remoção dos carboidratos. Deglicosilação produz grandes agregados solúveis, enfatizando o papel dos glicanos como inibidores de agregação. Amostras com apisimina parcialmente removida formam complexos diméricos com estequiometria (MRJP12/apisimina1). As informações produzidas neste trabalho podem contribuir para uma melhor compreensão da relação estrutura/função de MRJP1, que possui papéis únicos na biologia da abelha.Royal jelly (RJ) triggers the development of female honeybee larvae into queens. This effect has been attributed to the presence of major royal jelly protein 1 (MRJP1) in RJ. MRJP1 isolated from royal jelly is tightly associated with apisimin, a 54-residue -helical peptide that promotes the noncovalent assembly of MRJP1 into multimers. No high resolution structural data are available for these complexes, and their binding stoichiometry remains uncertain. We examined MRJP1/apisimin using a range of biophysical techniques. In addition, we investigated the behavior of deglycosylated samples, as well as samples with reduced apisimin content. Our mass spectrometry (MS) data demonstrated that the native complexes predominantly exist in a (MRJP14 apisimin4) stoichiometry. Blue native and showed the prevalence of tetrameric and monomeric structures in native conditions. Atomic force microscopy also showed two populations. Hydrogen/deuterium exchange (HDX) MS revealed that MRJP1 within these complexes is extensively disordered in the range of the residues 20-265. Marginally stable secondary structure (likely antiparallel -sheet) exists around residues 266-432. These weakly structured regions interchange with conformations that are extensively unfolded, giving rise to bimodal (EX1) isotope distributions. We propose that the native complexes have a “dimer of dimers” quaternary structure in which MRJP1 chains are bridged by apisimin. Specifically, our data suggest that apisimin acts as a linker that forms hydrophobic contacts involving the MRJP1 segment 316VLFFGLV322. MRJP1 has 2 glycosites located at amino acids 144 and 177. By using 2-DE, we observed 9 MRJP1 proteoforms, even after carbohydrate removal. Deglycosylation produces large soluble aggregates, highlighting the role of glycans as aggregation inhibitors. Samples with reduced apisimin content form dimeric complexes with a (MRJP12 apisimin1) stoichiometry. Therefore, the information uncovered in this work should help pave the way towards a better understanding of the structure/function relationship for MRJP1, which possesses unique roles in the honey bee biology

A relação escola e espaço: um estudo das escolas estaduais centrais de Campinas

Partindo do pressuposto que a Escola estabelece uma relação com o espaço no qual esta se situa, o presente trabalho buscou compreender como se dá tal relação. Não somente um sobre o outro, mas entende-se que o espaço interfere sobre a escola e vice-versa. Sendo assim, tendo o centro de Campinas como recorte espacial de análise e 4 escolas bem parecidas localizadas nesta região, a pesquisa propôs compreender como as características do espaço central, tão dinâmico e transformado ao longo do tempo, impactam as escolas que nele se localiza, trazendo desafios diferentes à sua gestão. No presente trabalho, a principal questão foi analisar como a localização no espaço urbano interfere na formação do público escolar