On Using Active Learning and Self-Training when Mining Performance Discussions on Stack Overflow

Abundant data is the key to successful machine learning. However, supervised learning requires annotated data that are often hard to obtain. In a classification task with limited resources, Active Learning (AL) promises to guide annotators to examples that bring the most value for a classifier. AL can be successfully combined with self-training, i.e., extending a training set with the unlabelled examples for which a classifier is the most certain. We report our experiences on using AL in a systematic manner to train an SVM classifier for Stack Overflow posts discussing performance of software components. We show that the training examples deemed as the most valuable to the classifier are also the most difficult for humans to annotate. Despite carefully evolved annotation criteria, we report low inter-rater agreement, but we also propose mitigation strategies. Finally, based on one annotator's work, we show that self-training can improve the classification accuracy. We conclude the paper by discussing implication for future text miners aspiring to use AL and self-training.Comment: Preprint of paper accepted for the Proc. of the 21st International Conference on Evaluation and Assessment in Software Engineering, 201

Genetic Algorithm Based Control System Design of a Self-Excited Induction Generator

This paper presents an application of the genetic algorithm (GA) for optimizing controller gains of the Self-Excited Induction Generator (SEIG) driven by the Wind Energy Conversion Scheme (WECS). The proposed genetic algorithm is introduced to adapt the integral gains of the conventional controllers of the active and reactive control loop of the system under study, where GA calculates the optimum value for the gains of the variables based on the best dynamic performance and a domain search of the integral gains. The proposed genetic algorithm is used to regulate the terminal voltage or reactive power control, by adjusting the self excitation, and to control the mechanical input power or active power control by adapting the blade angle of WECS, in order to adjust the stator frequency. The GA is used for optimizing these gains, for an active and reactive power loop, by solving the related optimization problem. The simulation results show a better dynamic performance using the GA than using the conventional PI controller for active and reactive control

Power System Stabilizer Driven by an Adaptive Fuzzy Set for Better Dynamic Performance

This paper presents a novel application of a fuzzy logic controller (FLC) driven by an adaptive fuzzy set (AFS) for a power system stabilizer (PSS).The proposed FLC, driven by AFS, is compared with a classical FLC, driven by a fixed fuzzy set (FFS). Both FLC algorithms use the speed error and its rate of change as input vectors. A single generator equipped with FLC-PSS and connected to an infinite bus bar through double transmission lines is considered. Both FLCs, using AFS and FFS, are simulated and tested when the system is subjected to different step changes in the reference value. The simulation results of the proposed FLC, using the adaptive fuzzy set, give a better dynamic response of the overall system by improving the damping coefficient and decreasing the rise time and settling time compared with classical FLC using FFS. The proposed FLC using AFS also reduces the computational time of the FLC as the number of rules is reduced.

MAT-715: SUSTAINABLE HIGH-VOLUME FLY ASH GROUTS FOR TWO-STAGE CONCRETE

Two-stage concrete (TSC) is a special type of concrete in which coarse aggregates are pre-placed in the formwork and subsequently injected with a grout. Beneficiating fly ash in TSC grouts increases TSC sustainability through the ecological use of large quantities of fly ash, reduced carbon-dioxide emissions associated with cement production, and enhancement of resource productivity of the concrete industry. Limited research has explored the effects of using high volume of fly ash as partial replacement for cement in TSC grout mixtures. Therefore, the flowability of grout mixtures incorporating various fly ash addition rates (i.e. 0%, 30%, 50% and 70%) was evaluated using the flow cone method and spread flow test. Correlations between the efflux time and spread flow for the grout mixtures were developed. Results show that increasing the fly ash addition reduced the grouts efflux time while increasing its spread flow. The optimum high-volume fly ash dosage for achieving high flowability and acceptable TSC compressive strength was identified

ACUTE TOXICITY OF DIFFERENT SIZES OF SILVER NANOPARTICLES INTRAPERITONALLY INJECTED IN BALB/C MICE USING TWO TOXICOLOGICAL METHODS

Objective: This study aimed to evaluate the acute toxicity of intraperitoneally administrated silver nanoparticles (AgNPs) with different particle sizes in BALB/c mice.Methods: Citrate-capped AgNPs were prepared by citrate reduction method and isolated into small particles (average size 20 nm) and large particles (average size 50 nm). The median lethal dose (LD50) of 20 nm and 50 nm AgNPs was estimated using two toxicological methods, classical Dixon's up-and-down method and AOT425statPgm method for up-and-down procedure.Results: The LD50 was evaluated at the dosage level of 169 and 213.8 mg/kg, respectively for 20 nm AgNPs and at the dosage level of 354 and 391.5 mg/kg, respectively for 50 nm AgNPs. The results showed that LD50 obtained by the AOT425statPgm method was in accord with that of the Dixon's method and no significant differences between them (P = 0.06). The size 20 nm AgNPs were more toxic than the size 50 nm AgNPs. The behavioural responses and deviations were dose dependent, increasing by increasing the dose. The anatomical examinations showed that AgNPs were mainly accumulated in liver and spleen of dosed mice.Conclusion: The results suggested that the AOT425statPgm method was an efficient tool and a good alternative method for use in future acute toxicity studies.Â

MAT-716: GREEN SIDEWALKS USING SUSTAINABLE TWO-STAGE CONCRETE

Two-stage concrete (TSC) is a special type of concrete, which has a high potential for use in sidewalk construction owing to its high volume stability. TSC is characterized by its high coarse aggregate content. Hence, using recycled solid waste materials as a coarse aggregate will increase TSC sustainability, while providing a cost-effective alternative to natural aggregates. Aggregates are pre-placed in TSC. Hence, water absorption by recycled concrete aggregates and the associated rheology problems do not exist in TSC. This study explores the performance of green TSC sidewalks incorporating recycled concrete aggregates (RCA) and crumb rubber from scrap tires. Mechanical properties of the proposed green TSC including compressive strength, modulus of elasticity, flexural strength and toughness, as well as durability to freeze-thaw cycles were investigated. Results show a slight reduction in TSC mechanical properties due to the use of RCA. Moreover, incorporating tire particles reduced TSC mechanical properties significantly, while improving its toughness and freeze-thaw resistance. Addition of recycled tire steel wires allowed to overcome the negative effects on the mechanical properties induced by crumb tire rubber. Therefore, recycling solid waste materials in TSC sidewalks can be an effective strategy to beneficiate such waste materials

SYNTHESIS, ANTITUMOR ACTIVITY, PHARMACOPHORE MODELING AND QSAR STUDIES OF NOVEL PYRAZOLES AND PYRAZOLO [1, 5-A] PYRIMIDINES AGAINST BREAST ADENOCARCINOMA MCF-7 CELL LINE

Objective: The present work aimed to synthesize New series of pyrazoles 3 and pyrazolo[1,5-a]pyrimidines 5, 7, 9 in order to evaluate their antiproliferative activity against human breast adenocarcinoma MCF-7cell line and study the cell cycle progression of the most active compounds. In addition, Pharmacophore modeling and QSAR Studies of these new compounds were done.Methods: The diazonium salt of 4-aminoacetophenone 1 was coupled with malononitrile in ethanol using sodium acetate affords 2-[(4-acetylphenyl)diazenyl] malononitrile Cycloaddition of hydrazine hydrate, in molar ratios 1:1 or 1:2, on compound 2, furnished 3,5-diaminopyrazolederivatives 3a and 3b respectively. Moreover, new pyrazolo[1,5-a]pyrimidine derivatives 5a-f were obtained upon cyclocondensation of 3a, b with different chalcones 4a-c in EtOH/piperidine,while compounds 7a-f were prepared via cycloaddition of 3a, b with various arylidene malononitriles 6a-c in the same reaction condition. Finally, treatment of 3a, b with ethyl 2-cyano-3-ethoxyacrylate 8a or 2-(ethoxymethylene)malononitrile 8b in EtOH/TEA yielded the novel pyrazolo[1,5-a]pyrimidine derivatives 9a, b respectively. These target compounds were screened for their cytotoxic activity against MCF-7 (human breast Cell Line) followed by study cell cycle of 7a. Finally, Pharmacophore modeling and QSAR Studies was carried out.Results: The pyrazolopyrimidine 7a was the most active compound (IC50 = 3.25 µM), whereas, some of the tested compounds exploited moderate growth inhibitory activity. Its effect was further studied on cell cycle progression; results showed that compound 7a induced cell cycle arrest at S-phase verifying this compound as a promising selective anticancer agent.Conclusion: Compound 7a was found to be the most active member against MCF-7 breast cancer (IC50= 3.25 μM), Further biological assessment of 7a using flow-cytometric analysis, revealed that it induced cell cycle arrest at S phase.Keywords: Pyrazole, Pyrazolo[1,5-a]pyrimidine, MCF-7 breast cancer cell line, Cell cycle profile, 3D pharmacophore,1 QSAR stud

O efeito das propriedades antioxidantes do extrato aquoso do alho e da Nigella sativa como agentes anti-esquistossômicos no camundongo

The aim of this study was to assess the antioxidant and anti-schistosomal activities of the garlic extract (AGE) and Nigella sativa oil (NSO) on normal and Schistosoma mansoni-infected mice. AGE (125 mg kg-1, i.p.) and NSO (0.2 mg kg-1, i.p.) were administrated separately or in combination for successive 28 days, starting from the 1st day post infection (pi). All mice were sacrificed at weeks 7 pi. Hematological and biochemical parameters including liver and kidney functions were measured to assess the progress of anemia, and the possibility of the tissue damage. Serum total protein level, albumin, globulin and cholesterol were also determined. Malondialdehyde (MDA) and glutathione (GSH) levels were determined in the liver tissues as biomarkers for oxidative and reducing status, respectively. The possible effect of the treatment regimens on Schistosoma worms was evaluated by recording percentage of the recovered worms, tissue egg and oogram pattern. Result showed that, protection with AGE and NSO prevented most of the hematological and biochemical changes and markedly improved the antioxidant capacity of schistosomiasis mice compared to the infected-untreated ones. In addition, remarkable reduction in worms, tissue eggs and alteration in oogram pattern were recorded in all the treated groups. The antioxidant and antischistosomal action of AGE and NSO was greatly diverse according to treatment regimens. These data point to these compounds as promising agents to complement schistosomiasis specific treatment.O propósito deste estudo foi verificar os efeitos anti-oxidantes e anti-esquistossômicos do extrato de alho (AGE) e do óleo da Nigella sativa (NSO) em camundongos normais e infectados com S. mansoni. AGE (125 mg/kg, i.p. ) e NSO (0,2 mg/kg, i.p.) foram administrados separadamente ou em combinação por 28 dias sucessivos começando do primeiro dia pós infecção (p.i.). Todos os camundongos foram sacrificados sete semanas p.i. Parâmetros hematológicos e bioquímicos incluindo funções renais e hepáticas foram medidos para avaliar o progresso da anemia e a possibilidade de dano tecidual. O nível total de proteínas séricas, albumina, globulina e colesterol foram também medidos. Níveis de malondialdeído (MDA) e glutationa (GSH) foram determinados em tecido hepático como biomarcações para o estado oxidativo e redutor, respectivamente. O possível efeito dos tratamentos sobre os vermes de Schistosoma foram avaliados através do percentual de vermes recuperados, ovos no tecido e o oograma. Resultados mostraram que a proteção com AGE e NSO preveniu a maior parte das alterações hematológicas e bioquímicas e melhoraram bastante a capacidade anti-oxidante de camundongos com esquistossomose comparados com aqueles infectados e não tratados. Adicionalmente, foi registrado uma acentuada redução nos vermes, ovos no tecido e alterações do oograma. A ação anti-oxidante e anti-esquistossômica do AGE e NSO foi diferente de acordo com os vários tratamentos. Estes dados mostram que estes compostos são agentes promissores para complementar o tratamento específico da esquistossomose

The Potential of Big Data Research in HealthCare for Medical Doctors’ Learning

The main goal of this article is to identify the main dimensions of a model proposal for increasing the potential of big data research in Healthcare for medical doctors’ (MDs’) learning, which appears as a major issue in continuous medical education and learning. The paper employs a systematic literature review of main scientific databases (PubMed and Google Scholar), using the VOSviewer software tool, which enables the visualization of scientific landscapes. The analysis includes a co-authorship data analysis as well as the co-occurrence of terms and keywords. The results lead to the construction of the learning model proposed, which includes four health big data key areas for MDs’ learning: 1) data transformation is related to the learning that occurs through medical systems; 2) health intelligence includes the learning regarding health innovation based on predictions and forecasting processes; 3) data leveraging regards the learning about patient information; and 4) the learning process is related to clinical decision-making, focused on disease diagnosis and methods to improve treatments. Practical models gathered from the scientific databases can boost the learning process and revolutionise the medical industry, as they store the most recent knowledge and innovative research