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Nabaho, Lazarus, and Wilberforce Turyasingura. "An exploration of the ‘African (Union Commission’s) perspective’ of quality and quality assurance in higher education: Latent voices in the African Quality Rating Mechanism (AQRM)." Tuning Journal for Higher Education 6, no. 2 (2019): 73–95. http://dx.doi.org/10.18543/tjhe-6(2)-2019pp73-95.
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Quality assurance of African higher education is at the top of the region’s development agenda. Prompted by the imperative to enhance the quality of higher education, the Africa Union Commission is implementing the African Quality Rating Mechanism (AQRM). The AQRM is a continental tool that affords higher education institutions an opportunity to conduct self-assessment and compare their performance against similar institutions based on a set of common criteria. The mechanism is envisaged to engender institutional cultures of quality and enhance the quality of African higher education. However, a dearth of knowledge exists about the latent notions of quality in higher education that the AQRM aims to assure and the implicit institutional-level quality assurance practices in the AQRM. Therefore, this interpretivist article, based on a review of the AQRM survey questionnaire, answered the following research question: What notions of quality in higher education and the institutional-level quality assurance practices are inherent in the quality standards of the AQRM survey questionnaire? The findings revealed that quality as fitness for purpose and exceptional are the notions of quality in higher education in the AQRM. Nevertheless, fitness for purpose is the dominant notion of quality and this symbolises an imperative to re-direct higher education to serve social and economic ends. Distinguished (excellent) teacher awards, applied research excellence awards, staff professional development, tracer studies, external examination, and the involvement of key external stakeholders in programme development are the latent institutional-level quality assurance practices in the AQRM. These quality assurance practices are in sync with the notions of quality and aim at bridging the gap between the academy and the labour market. Methodologically, the AQRM survey questionnaire is devoid of benchmarks to inform the rating, and quality assurance practices such as student evaluation of teaching, peer observation of teaching and moderation of examination items are unnoticeable in the survey questionnaire.Received: 28 December 2018Accepted: 19 April 2019Published online: 29 May 2019
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Leite, Débora Brunheroto Pasin, and Rodrigo Braga Moruzzi. "Considerações sobre os valores máximos permitidos (VMP) de E. coli em águas cinza, visando ao reúso por meio de avaliação quantitativa de riscos microbiológicos (AQRM)." Engenharia Sanitaria e Ambiental 22, no. 1 (2016): 57–64. http://dx.doi.org/10.1590/s1413-41522016119617.
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RESUMO O presente trabalho teve como objetivo aplicar a ferramenta de avaliação quantitativa de riscos microbiológicos (AQRM) para avaliação do reúso de águas cinza, a fim de definir uma faixa de valores máximos permitidos (VMP) para Escherichia coli por meio do conceito de riscos aceitáveis 10-3 e 10-6 por pessoa por ano (pppa), para as diversas finalidades de reúso. Para tal, foram avaliadas a exposição, a dose-resposta e a probabilidade de infecção para diferentes finalidades de reúso. O modelo de Beta-Poisson foi empregado para a avaliação da probabilidade de infecção. Os dados de entrada para AQRM foram avaliados mediante a compilação sistemática de dados da literatura. Os maiores riscos de infecção decorrem das culturas alimentares e da balneabilidade com águas cinza misturadas, resultando em VMP de 5,25 a 105 Número Mais Provável (NMP)/100 mL e de 3,95 a 39,5 NMP/100 mL respectivamente, para risco aceitável de 10-3 e 0,00 a 0,10 NMP/100 mL e 0,00 a 0,04 NMP/100 mL, simultaneamente, para risco de 10-6 pppa. Já o menor risco de infecção decorre do reúso de águas cinza de lavatório para lavagem de pisos, proporcionando VMP de 21,4 × 101 a 2,14 × 103 NMP/100 mL para risco aceitável de 10-3 e 0,71 a 14,3 NMP/100 mL, sucessivamente, para risco de 10-6 pppa. A AQRM com riscos aceitáveis de 10-3 pppa mostra-se uma potencial ferramenta para avaliação dos VMP em água cinza bruta, visando sua reutilização, e pode subsidiar decisões normativas nacionais.
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Hanna, Ramzi K. "Some macrofossils from the Aqra Limestone Formation (Maastrichtian), Aqra, Northern Iraq." Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 1995, no. 5 (1995): 295–304. http://dx.doi.org/10.1127/njgpm/1995/1995/295.
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Velasco, Isabel, Sandra Tenreiro, Isabel L. Calderon, and Bruno André. "Saccharomyces cerevisiae Aqr1 Is an Internal-Membrane Transporter Involved in Excretion of Amino Acids." Eukaryotic Cell 3, no. 6 (2004): 1492–503. http://dx.doi.org/10.1128/ec.3.6.1492-1503.2004.
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ABSTRACT Excretion of amino acids by yeast cells was reported long ago but has not been characterized in molecular terms. It is typically favored by overproduction of the amino acid and/or impairment of its uptake. Here we describe the construction of a yeast strain excreting threonine and homoserine. Using this excretor strain, we then applied a reverse-genetics approach and found that the transporter encoded by the YNL065w/AQR1 gene, a protein thought to mediate H+ antiport, is involved in homoserine and threonine excretion. Furthermore, overexpression of AQR1 led to increased excretion of several amino acids (alanine, aspartate, and glutamate) known to be relatively abundant in the cytosol. Transcription of the AQR1 gene is induced severalfold by a number of amino acids and appears to be under the negative control of Gcn4. An Aqr1-green fluorescent protein fusion protein is located in multiple internal membrane structures and appears to cycle continuously between these compartments and the plasma membrane. The Aqr1 sequence is significantly similar to the vesicular amine transporters of secretory vesicles of neuronal cells. We propose that Aqr1 catalyzes transport of excess amino acids into vesicles, which then release them in the extracellular space by exocytosis.
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Pope, R. J., M. P. Chipperfield, N. H. Savage, et al. "Evaluation of a regional air quality model using satellite column NO<sub>2</sub>: treatment of observation errors and model boundary conditions and emissions." Atmospheric Chemistry and Physics Discussions 14, no. 15 (2014): 21749–84. http://dx.doi.org/10.5194/acpd-14-21749-2014.
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Abstract. We compare tropospheric column NO2 between the UK Met Office operational Air Quality in the Unified Model (AQUM) and satellite observations from the Ozone Monitoring Instrument (OMI) for 2006. Column NO2 retrievals from satellite instruments are prone to large uncertainty from random, systematic and smoothing errors. We present an algorithm to reduce the random error of time-averaged observations, once smoothing errors have been removed with application of satellite averaging kernels to the model data. This reduces the total error in seasonal mean columns by 30–90%, which allows critical evaluation of the model. The standard AQUM configuration evaluated here uses chemical lateral boundary conditions (LBCs) from the GEMS (Global and regional Earth-system Monitoring using Satellite and in-situ data) reanalysis. In summer the standard AQUM overestimates column NO2 in northern England and Scotland, but underestimates it over continental Europe. In winter, the model overestimates column NO2 across the domain. We show that missing heterogeneous hydrolysis of N2O5 in AQUM is a significant sink of column NO2 and that the introduction of this process corrects some of the winter biases. The sensitivity of AQUM summer column NO2 to different chemical LBCs and NOx emissions datasets are investigated. Using Monitoring Atmospheric Composition and Climate (MACC) LBCs increases AQUM O3 concentrations compared with the default GEMS LBCs. This enhances the NOx-O3 coupling leading to increased AQUM column NO2 in both summer and winter degrading the comparisons with OMI. Sensitivity experiments suggest that the cause of the remaining northern England and Scotland summer column NO2 overestimation is the representation of point source (power station) emissions in the model.
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Pope, R. J., M. P. Chipperfield, N. H. Savage, et al. "Evaluation of a regional air quality model using satellite column NO<sub>2</sub>: treatment of observation errors and model boundary conditions and emissions." Atmospheric Chemistry and Physics 15, no. 10 (2015): 5611–26. http://dx.doi.org/10.5194/acp-15-5611-2015.
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Abstract. We compare tropospheric column NO2 between the UK Met Office operational Air Quality in the Unified Model (AQUM) and satellite observations from the Ozone Monitoring Instrument (OMI) for 2006. Column NO2 retrievals from satellite instruments are prone to large uncertainty from random, systematic and smoothing errors. We present an algorithm to reduce the random error of time-averaged observations, once smoothing errors have been removed with application of satellite averaging kernels to the model data. This reduces the total error in seasonal mean columns by 10–70%, which allows critical evaluation of the model. The standard AQUM configuration evaluated here uses chemical lateral boundary conditions (LBCs) from the GEMS (Global and regional Earth-system Monitoring using Satellite and in situ data) reanalysis. In summer the standard AQUM overestimates column NO2 in northern England and Scotland, but underestimates it over continental Europe. In winter, the model overestimates column NO2 across the domain. We show that missing heterogeneous hydrolysis of N2O5 in AQUM is a significant sink of column NO2 and that the introduction of this process corrects some of the winter biases. The sensitivity of AQUM summer column NO2 to different chemical LBCs and NOx emissions data sets are investigated. Using Monitoring Atmospheric Composition and Climate (MACC) LBCs increases AQUM O3 concentrations compared with the default GEMS LBCs. This enhances the NOx–O3 coupling leading to increased AQUM column NO2 in both summer and winter degrading the comparisons with OMI. Sensitivity experiments suggest that the cause of the remaining northern England and Scotland summer column NO2 overestimation is the representation of point source (power station) emissions in the model.
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Khatari, Maimuna, A. A. Zaidan, B. B. Zaidan, O. S. Albahri, and M. A. Alsalem. "Multi-Criteria Evaluation and Benchmarking for Active Queue Management Methods: Open Issues, Challenges and Recommended Pathway Solutions." International Journal of Information Technology & Decision Making 18, no. 04 (2019): 1187–242. http://dx.doi.org/10.1142/s0219622019300039.
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The evaluation and benchmarking processes of active queue management (AQM) methods are complicated and challenging. Several evaluation criteria/metrics must be considered before an AQM method can yield satisfactory performance using specific metric(s). Further investigations are required to highlight the limitations of how criteria/metrics are determined and how their procedures accord with the evaluation and benchmarking processes of AQM. In this paper, we presented comprehensive insights into the multi-criteria evaluation and benchmarking of AQM methods based on two critical directions. First, current AQM evaluation criteria are collected, analyzed and categorized. Second, these AQM evaluation criteria highlight conflicting issues and benchmarking techniques to identify weak points, and possible solutions are discussed. The findings of this study are as follows: (1) The limitations and problems of existing AQM evaluation and benchmarking methods, such as multi-evaluation criteria, criteria trade-off, benchmarking and criteria significance, are presented and emphasized. (2) Multi-criteria decision-making using multiple criteria, such as performance, processing overhead and configuration, can be used to benchmark numerous AQM methods to determine solutions for future directions.
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Kim, Young-Min, Inbo Oh, Jihyun Kim, Yoon-Hee Kang, and Kangmo Ahn. "Harmful Effects of Ambient Nitrogen Dioxide on Atopic Dermatitis: Comparison of Exposure Assessment Based on Monitored Concentrations and Modeled Estimates." Atmosphere 11, no. 9 (2020): 921. http://dx.doi.org/10.3390/atmos11090921.
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Precise exposure assessment of air pollutants is crucial in epidemiologic studies to ensure valid estimates of health effects. We conducted a longitudinal study to evaluate the role of air quality monitoring (AQM) measurements and high-resolution modeling outcomes focusing on nitrogen dioxide (NO2) exposure and atopic dermatitis (AD). A total of 128 young children with AD in Seoul Metropolitan Area, Korea, were recruited as a panel. We estimated the participants’ exposure to NO2 for four months, from 1 April through 31 July 2014 based on (1) monitored levels from 60 AQM stations located at varying distances from residential areas (AQM station-based NO2, AQM-NO2) and (2) estimates from a community multi-scale air quality (CMAQ) modeling system with a high-resolution (1 × 1 km) (CMAQ-NO2). We then compared the effect of AQM-NO2 on AD symptoms with that of CMAQ-NO2. The average distance between the participants’ residences and the nearest AQM station was 2.03 ± 1.06 km, ranging from 0.28 km to 5.73 km. Based on AQM-NO2, the AD symptoms increased by 10.28% (95% confidence interval (CI): 3.24, 17.79) with an increase of 10 ppb of NO2. The effect estimates of CMAQ-NO2 were similar to those of AQM-NO2 when assessed in patients living within 3 km from the nearest AQM station. Even within 1 km, the CI estimate obtained from the CMAQ was much narrower than from AQM (44.18–49.54 vs. 7.02–64.75). However, the association of AQM-NO2 with AD symptoms of patients living beyond 3 km was not positive, whereas that of CMAQ-NO2 maintained positive. In conclusion, exposure to ambient NO2 is significantly associated with aggravation of AD symptoms in young children. In addition, our study suggests that exposure assessment of NO2 using measurement data obtained from monitoring stations far from residential locations can lead to misclassification bias.
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Li, Jin, Fengfei Wang, Harvey Mamon, et al. "Antiprimer Quenching-Based Real-Time PCR and Its Application to the Analysis of Clinical Cancer Samples." Clinical Chemistry 52, no. 4 (2006): 624–33. http://dx.doi.org/10.1373/clinchem.2005.063321.
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Abstract Background: Nucleic acid amplification plays an increasingly important role in genetic analysis of clinical samples, medical diagnostics, and drug discovery. We present a novel quantitative PCR technology that combines the advantages of existing methods and allows versatile and flexible nucleic acid target quantification in clinical samples of widely different origin and quality. Methods: We modified one of the 2 PCR primers by use of an oligonucleotide “tail” fluorescently labeled at the 5′ end. An oligonucleotide complementary to this tail, carrying a 3′ quenching molecule (antiprimer), was included in the reaction along with 2 primers. After primer extension, the reaction temperature was lowered such that the antiprimer hybridizes and quenches the fluorescence of the free primer but not the fluorescence of the double-stranded PCR product. The latter provides real-time fluorescent product quantification. This antiprimer-based quantitative real-time PCR method (aQRT-PCR) was used to amplify and quantify minute amounts of input DNA for genes important to cancer. Results: Simplex and multiplex aQRT-PCR demonstrated linear correlation (r2 &gt;0.995) down to a DNA input equivalent to 20 cells. Multiplex aQRT-PCR reliably identified the HER-2 gene in microdissected breast cancer samples; in formalin-fixed, paraffin-embedded specimens; and in plasma circulating DNA from cancer patients. Adaptation to multiplex single-nucleotide polymorphism detection via allele-specific aQRT-PCR allowed correct identification of apolipoprotein B polymorphisms in 51 of 51 human specimens. Conclusion: The simplicity, versatility, reliability, and low cost of aQRT-PCR make it suitable for genetic analysis of clinical specimens.
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Liu, Ling, Calton Pu, David Buttler, Wei Han, Henrique Paques, and Wei Tang. "AQR-toolkit." ACM SIGMOD Record 29, no. 2 (2000): 597. http://dx.doi.org/10.1145/335191.336579.
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Savage, N. H., P. Agnew, L. S. Davis, et al. "Air quality modelling using the Met Office Unified Model: model description and initial evaluation." Geoscientific Model Development Discussions 5, no. 4 (2012): 3131–82. http://dx.doi.org/10.5194/gmdd-5-3131-2012.
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Abstract. The on-line air quality model AQUM (Air Quality in the Unified Model) is a limited-area forecast configuration of the Met Office Unified Model which uses the UKCA (UK Chemistry and Aerosols) sub-model. AQUM has been developed with two aims: as an operational system to deliver regional air quality forecasts and as a modelling system to enable air quality studies to be conducted to inform policy decisions relating to emissions controls. This paper presents a description of the model and the methods used to evaluate the performance of the forecast system. Results are presented of evaluation studies conducted for a year-long period of operational forecast trials and several past cases of poor air quality episodes. To place the model performance in context we compare AQUM ozone forecasts with those of another forecasting system, the MACC ensemble, for a 5-month period. The results demonstrate that AQUM has a large dynamic range of modelled ozone levels and has a good level of responsiveness to elevated ozone episode conditions – a characteristic which is essential for forecasting poor air quality episodes. An analysis of the variation of model skill with forecast lead-time is presented and the insights this provides to the relative sources of error in air quality modelling are discussed.
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Keulen, Nynke, Sebastian Næsby Malkki, and Shaun Graham. "Automated Quantitative Mineralogy Applied to Metamorphic Rocks." Minerals 10, no. 1 (2020): 47. http://dx.doi.org/10.3390/min10010047.
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The ability to apply automated quantitative mineralogy (AQM) on metamorphic rocks was investigated on samples from the Fiskenæsset complex, Greenland. AQM provides the possibility to visualize and quantify microstructures, minerals, as well as the morphology and chemistry of the investigated samples. Here, we applied the ZEISS Mineralogic software platform as an AQM tool, which has integrated matrix corrections and full quantification of energy dispersive spectrometry data, and therefore is able to give detailed chemical information on each pixel in the AQM mineral maps. This has been applied to create mineral maps, element concentration maps, element ratio maps, mineral association maps, as well as to morphochemically classify individual minerals for their grain shape, size, and orientation. The visualization of metamorphic textures, while at the same time quantifying their textures, is the great strength of AQM and is an ideal tool to lift microscopy from the qualitative to the quantitative level.
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Blinova, A. A., M. M. Romanova, G. V. Ustyugova, A. V. Koldoba, and R. V. E. Lovelace. "Comparisons of MHD propeller model with observations of cataclysmic variable AE Aqr." Monthly Notices of the Royal Astronomical Society 487, no. 2 (2019): 1754–63. http://dx.doi.org/10.1093/mnras/stz1314.
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ABSTRACT We have developed a numerical magnetohydrodynamic (MHD) model of the propeller candidate star AE Aqr using axisymmetric MHD simulations. We suggest that AE Aqr is an intermediate polar-type star, where the magnetic field is relatively weak and an accretion disc may form around the white dwarf. The star is in the propeller regime, and many of its observational properties are determined by the disc–magnetosphere interaction. Comparisons of the characteristics of the observed versus modelled AE Aqr star show that the model can explain many observational properties of AE Aqr. In a representative model, the magnetic field of the star is B ≈ 3.3 × 105 G and the time-averaged accretion rate in the disc is 5.5 × 1016 g s−1. Most of this matter is ejected into conically shaped winds. The numerical model explains the rapid spin-down of AE Aqr through the outflow of angular momentum from the surface of the star to the wind, corona, and disc. The energy budget in the outflows, 9 × 1033 erg s−1, is sufficient for explaining the observed flaring radiation in different wavebands. The time-scale of ejections into the wind matches the short time-scale variability in the light curves of AE Aqr.
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Savage, N. H., P. Agnew, L. S. Davis, et al. "Air quality modelling using the Met Office Unified Model (AQUM OS24-26): model description and initial evaluation." Geoscientific Model Development 6, no. 2 (2013): 353–72. http://dx.doi.org/10.5194/gmd-6-353-2013.
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Abstract. The on-line air quality model AQUM (Air Quality in the Unified Model) is a limited-area forecast configuration of the Met Office Unified Model which uses the UKCA (UK Chemistry and Aerosols) sub-model. AQUM has been developed with two aims: as an operational system to deliver regional air quality forecasts and as a modelling system to conduct air quality studies to inform policy decisions on emissions controls. This paper presents a description of the model and the methods used to evaluate the performance of the forecast system against the automated UK surface network of air quality monitors. Results are presented of evaluation studies conducted for a year-long period of operational forecast trials and several past cases of poor air quality episodes. The results demonstrate that AQUM tends to over-predict ozone (~8 μg m−3 mean bias for the year-long forecast), but has a good level of responsiveness to elevated ozone episode conditions – a characteristic which is essential for forecasting poor air quality episodes. AQUM is shown to have a negative bias for PM10, while for PM2.5 the negative bias is much smaller in magnitude. An analysis of speciated PM2.5 data during an episode of elevated particulate matter (PM) suggests that the PM bias occurs mainly in the coarse component. The sensitivity of model predictions to lateral boundary conditions (LBCs) has been assessed by using LBCs from two different global reanalyses and by comparing the standard, single-nested configuration with a configuration having an intermediate European nest. We conclude that, even with a much larger regional domain, the LBCs remain an important source of model error for relatively long-lived pollutants such as ozone. To place the model performance in context we compare AQUM ozone forecasts with those of another forecasting system, the MACC (Monitoring Atmospheric Composition and Climate) ensemble, for a 5-month period. An analysis of the variation of model skill with forecast lead time is presented and the insights this provides to the relative sources of error in air quality modelling are discussed.
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Bencherif, Adib. "Les théories des mouvements sociaux et la dialectique des niveaux : un cadre d’analyse pour l’étude des évolutions d’Al-Qaïda au Maghreb islamique." Canadian Graduate Journal of Sociology and Criminology 2, no. 2 (2013): 102–13. http://dx.doi.org/10.15353/cgjsc.v2i2.3770.
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Les théories des mouvements sociaux sont de plus en plus utilisées pour étudier les groupesterroristes. Elles comportent différents niveaux d’analyse: les niveaux macro-analytique,méso-analytique et micro-analytique. Le présent article tente d’adapter ce corpusthéorique à l’étude du groupe jihadiste Al-Qaïda au Maghreb islamique (AQMI). En effet,au cours des dernières années, AQMI ne s’est pas développé au Maghreb alors que sesactivités ont augmenté exponentiellement dans la région sahélienne, au point d’ydévelopper un sanctuaire pour le groupe au nord du Mali. Le développement d’AQMI auSahel est-il alors le résultat de choix stratégiques ou celui de dynamiques internes ? Pourexpliquer le développement d’AQMI dans la région sahélo-saharienne, l’auteur proposeune grille de lecture basée sur les niveaux macro et méso-analytiques et sur leur mise endialectique. Le niveau macro-analytique met en lumière la structure des opportunitéspolitiques induisant les choix stratégiques d’AQMI et le niveau méso-analytique lesdynamiques internes du groupe. La littérature existante sur AQMI étant principalementconstituée de monographies et de notes de recherches, l’ambition de cet article est alorsde concilier théorie et recherche empirique. Ainsi le cadre d’analyse proposé est inspirédes approches de l’action collective et de la mobilisation des ressources et cherche àaméliorer la compréhension des évolutions du groupe. L’étude menée est une analysequalitative centrée sur les États algérien et malien.The theories of social movements are increasingly used to study terrorist groups and theyare characterized by three different levels of analysis: macro, meso, and micro. This article attempts to adapt this theoretical framework to the study of the jihadist group al-Qaeda in the Islamic Maghreb (AQIM). Indeed, in recent years, AQIM failed to develop in North Africa while its activities have increased exponentially in the Sahel region, to the point ofdeveloping a sanctuary for the group in northern Mali. Is the development of AQIM in the Sahel the result of strategic choices or internal dynamics? To explain the development of AQIM in the Sahel-Saharan region, the author proposes a reading grid based on the macroand meso levels of analysis and their dialectical implementation. The macro-level analysis highlights the political opportunities structure inducing AQIM strategic choices and the meso-level analysis focuses on internal dynamics of the group. Seeing as existing literatureon AQIM is mainly constituted of monographs and research notes, the intent of this paperis then to reconcile theory and empirical research. Thus, the proposed framework is inspired from collective action and resource mobilization approaches and seeks to improve the understanding of the evolution of the group. The study is a qualitative analysis focusingon the Algerian and Malian States.
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Halverson, Jeffry R., and Nathaniel Greenberg. "Ideology as Narrative." Middle East Journal of Culture and Communication 10, no. 1 (2017): 3–23. http://dx.doi.org/10.1163/18739865-01001002.
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This article examines a corpus of extremist Islamist texts for the period from 2007 to 2012, including transcripts of audio and videos produced by al-Qaeda in the Islamic Maghrib (AQIM). Utilizing narrative analysis, we examine the way AQIM used mythic discourse to disseminate its ideology to audiences and to defend its actions and focus on the deployment of longstanding culturally-embedded ‘master narratives’ in fragmentary forms as sense-making devices. In the process, we argue that narrative analysis can provide insights into ideologies and organizations in the Middle East and North African region that may elude other analytical methods.
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Akis, V. N., and D. W. Curtis. "A characterisation of the absolute quasi-retracts in a class of acyclic continua." Bulletin of the Australian Mathematical Society 36, no. 2 (1987): 227–37. http://dx.doi.org/10.1017/s0004972700026502.
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The class of quasi-retracts of AR's (AQR's) was first considered by Stallings, who observed that every AQR has the fixed point property. More recently, it has been shown that the class of AQR's is closed with respect to the operations of taking cones, suspensions, or products with AR's, and that no AQR separates a Euclidean space. In this paper we show that every AQR is acyclic, and we obtain a simple, direct characterization of the AQR's in a certain class of acyclic continua.
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Hohenberger, Tilman Leo, Wenwei Che, Jimmy C. H. Fung, and Alexis K. H. Lau. "A proposed population-health based metric for evaluating representativeness of air quality monitoring in cities: Using Hong Kong as a demonstration." PLOS ONE 16, no. 5 (2021): e0252290. http://dx.doi.org/10.1371/journal.pone.0252290.
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City air quality monitoring (AQM) network are typically sparsely distributed due to high operation costs. It is of the question of how well it can reflect public health risks to air pollution given the diversity and heterogeneity in pollution, and spatial variations in population density. Combing high-resolution air quality model, spatial population distribution and health risk factors, we proposed a population-health based metric for AQM representativeness. This metric was demonstrated in Hong Kong using hourly modelling data of PM10, PM2.5, NO2 and O3 in 2019 with grid cells of 45m * 48m. Individual and total hospital admission risks (%AR) of these pollutants were calculated for each cell, and compared with those calculated at 16 monitoring sites using the similarity frequency (SF) method. AQM Representativeness was evaluated by SF and a population-health based network representation index (PHNI), which is population-weighted SF over the study-domain. The representativeness varies substantially among sites as well as between population- and area-based evaluation methods, reflecting heterogeneity in pollution and population. The current AQM network reflects population health risks well for PM10 (PHNI = 0.87) and PM2.5 (PHNI = 0.82), but is less able to represent risks for NO2 (PHNI = 0.59) and O3 (PHNI = 0.78). Strong seasonal variability in PHNI was found for PM, increasing by >11% during autumn and winter compared to summer due to regional transport. NO2 is better represented in urban than rural, reflecting the heterogeneity of urban traffic pollution. Combined health risk (%ARtotal) is well represented by the current AQM network (PHNI = 1), which is more homogenous due to the dominance and anti-correlation of NO2 and O3 related %AR. The proposed PHNI metric is useful to compare the health risk representativeness of AQM for individual and multiple pollutants and can be used to compare the effectiveness of AQM across cities.
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Chydziñski, Andrzej, and Łukasz Chróst. "Analysis of AQM queues with queue size based packet dropping." International Journal of Applied Mathematics and Computer Science 21, no. 3 (2011): 567–77. http://dx.doi.org/10.2478/v10006-011-0045-7.
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Analysis of AQM queues with queue size based packet dropping Queueing systems in which an arriving job is blocked and lost with a probability that depends on the queue size are studied. The study is motivated by the popularity of Active Queue Management (AQM) algorithms proposed for packet queueing in Internet routers. AQM algorithms often exploit the idea of queue-size based packet dropping. The main results include analytical solutions for queue size distribution, loss ratio and throughput. The analytical results are illustrated via numerical examples that include some commonly used blocking probabilities (dropping functions).
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Amigó, José M., Guillem Duran, Ángel Giménez, José Valero, and Oscar Martinez Bonastre. "Modeling a New AQM Model for Internet Chaotic Behavior Using Petri Nets." Applied Sciences 11, no. 13 (2021): 5877. http://dx.doi.org/10.3390/app11135877.
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Formal modeling is considered one of the fundamental phases in the design of network algorithms, including Active Queue Management (AQM) schemes. This article focuses on modeling with Petri nets (PNs) a new scheme of AQM. This innovative AQM is based on a discrete dynamical model of random early detection (RED) for controlling bifurcations and chaos in Internet congestion control. It incorporates new parameters (α,β) that make possible better stability control over oscillations of an average queue length (AQL) at the router. The PN is validated through the matrix equation approach, reachability tree, and invariant analysis. The correctness is validated through the key properties of reachability, boundedness, reversibility, deadlock, and liveness.
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Fan, Xun Li, Fei Fei Du, and Zhen Hua Xie. "Input-Rate Based Adaptive Fuzzy Neuron PID Control for AQM." Advanced Materials Research 846-847 (November 2013): 3–8. http://dx.doi.org/10.4028/www.scientific.net/amr.846-847.3.
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Internet routers play an important role during network congestion. All the routers have buffers at input and output ports to hold the packets at congestion. Various congestion control algorithms have been proposed to control the congestion. Recently, some proportional-integral-derivative (PID) controller based algorithms have been proposed as Active Queue Management (AQM) schemes to address performance degradations of end-to-end TCP congestion control. However, most of the proposed PID-controllers for AQM are validated for their performance and stability via intuitive explanation and simulation studies instead of theoretic analysis and performance evaluation. But there are a few drawbacks of PID-controller based AQM algorithms leading to poor performance like causing data retention dropping and oscillation when the time delay is large, which means that the existing PID-controller can not meet the Quality of Service (QoS) requirements. To overcome the drawbacks of traditional PID, we analyze and enhance the PID-controller based AQM algorithm by regarding the TCP congestion control mechanism as an input-rate based Adaptive Fuzzy Neuron PID control algorithm (IRAFNPID) to avoid congestion in TCP/AQM networks. By means of simulations, we evaluate and compare the performance of traditional PID, single neural adaptive PID(SNAPID) and IRAFNPID, simulations with experiment data analysis and find that IRAFNPID has better convergence, stability, robustness, goodput and lower loss ratio.
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Sigauke, Caston, Murendeni Nemukula, and Daniel Maposa. "Probabilistic Hourly Load Forecasting Using Additive Quantile Regression Models." Energies 11, no. 9 (2018): 2208. http://dx.doi.org/10.3390/en11092208.
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Short-term hourly load forecasting in South Africa using additive quantile regression (AQR) models is discussed in this study. The modelling approach allows for easy interpretability and accounting for residual autocorrelation in the joint modelling of hourly electricity data. A comparative analysis is done using generalised additive models (GAMs). In both modelling frameworks, variable selection is done using least absolute shrinkage and selection operator (Lasso) via hierarchical interactions. Four models considered are GAMs and AQR models with and without interactions, respectively. The AQR model with pairwise interactions was found to be the best fitting model. The forecasts from the four models were then combined using an algorithm based on the pinball loss (convex combination model) and also using quantile regression averaging (QRA). The AQR model with interactions was then compared with the convex combination and QRA models and the QRA model gave the most accurate forecasts. Except for the AQR model with interactions, the other two models (convex combination model and QRA model) gave prediction interval coverage probabilities that were valid for the 90 % , 95 % and the 99 % prediction intervals. The QRA model had the smallest prediction interval normalised average width and prediction interval normalised average deviation. The modelling framework discussed in this paper has established that going beyond summary performance statistics in forecasting has merit as it gives more insight into the developed forecasting models.
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Grazia, Carlo Augusto, Natale Patriciello, Martin Klapez, and Maurizio Casoni. "Transmission Control Protocol and Active Queue Management together against congestion: cross-comparison through simulations." SIMULATION 95, no. 10 (2018): 979–93. http://dx.doi.org/10.1177/0037549718814626.
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Most Internet traffic is carried by the Transmission Control Protocol (TCP) nowadays, even in the case of real-time services. Detecting and mitigating the congestion is one of the primary tasks of this protocol, in fact, different TCP versions are defined by their congestion control algorithms. Furthermore, Active Queue Management (AQM) algorithms share the same goal of congestion mitigation with TCP; in particular, the most efficient congestion control occurs when AQM and TCP work together. This paper presents a brief survey and a cross-comparison of the latest and most important TCP and AQM variants, then provides an evaluation of a different kind of performance on the ns-3 network simulator over various types of environments (multiple Round Trip Time, long delay, different congestion levels, etc.). In any shared bottleneck, the choice of the TCP-AQM couple to adopt is crucial. We will show that the results are not univocal and the “one size fits all” solution does not exist. Moreover, the proper couple depends on the performance that we want to boost and on the environment that we have to deal with.
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Dovzhenko, Timur. "DSREM REGULATOR IN THE TCP/IP NETWORK." EUREKA: Physics and Engineering 4 (July 29, 2016): 39–46. http://dx.doi.org/10.21303/2461-4262.2016.000127.
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The paper presents the main parameters and describes the behavior of the active queue management (AQM) algorithm which based on random exponential marking (REM) packets in TCP/IP network. It has presented the new AQM algorithm, which has been developed by author, which is based on REM and uses dynamically splitting marking characteristic (DSREM) of network packets. The basic parameters and functional principle of DSREM algorithm have been shown. Block diagram of linearized AQM system, which is based on DSREM management law and describes its main components, is shown. Transfer characteristic for DSREM, which is based on the Laplace transform and its basic parameters, are considered. Simulation of TCP/IP network, which contains congested link for small and large sources of incoming messages using REM and DSREM regulators, is done. Log-frequency characteristics for REM and DSREM methods are obtained and their comparative analysis is performed. It is concluded that the regulator based on DSREM algorithm has better performance and stability of the system can be used in the AQM system.
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Piotrowska, Agnieszka. "On Cross-Layer Interactions for Congestion Control in the Internet." Applied Sciences 11, no. 17 (2021): 7808. http://dx.doi.org/10.3390/app11177808.
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Two key mechanisms of the Internet are congestion control in the Transmission Control Protocol (TCP) and Active Queue Management (AQM) in routers. The former divides the bandwidth between flows and prevents the Internet from congestion collapse. Simultaneously, the latter informs hosts of the forthcoming congestion by preventive dropping of packets in network nodes. Although these two key mechanisms may severely interact with each other, they are often being researched independently, in parallel. This has led to the development of a few new congestion controls and AQM algorithms known for excellent performance under the assumption that the counterpart remains unaltered. It is unclear, however, how these new solutions in both areas interact with each other. The purpose of this paper is to fill this gap. Namely, in an extensive set of simulations, the impact of interactions between the state-of-the-art congestion control and AQM algorithms on the TCP connection performance is studied. As a result, recommendations for using some particular TCP-AQM pairs, which are observed to perform especially well, are formulated.
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Ghaib, Fadhil A., Salih K. Abdul-Karim, and Rashied J. Mohammad. "A Reconnaissance Gravity and Magnetic Study in Aqra Plain." Journal of Zankoy Sulaimani - Part A 5, no. 2 (2001): 51–62. http://dx.doi.org/10.17656/jzs.10101.
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Kim, Chun-Hwey, Jang-Hae Jeong, and Yong-Sam Lee. "LIGHT-TIME EFFECTS IN TWO ECLIPSING BINARIES V343 AQL AND CX AQR." Journal of Astronomy and Space Sciences 22, no. 2 (2005): 113–24. http://dx.doi.org/10.5140/jass.2005.22.2.113.
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Stern, R. A., and J. J. Drake. "EUVE Observations of BY Dra Systems." International Astronomical Union Colloquium 152 (1996): 135–40. http://dx.doi.org/10.1017/s0252921100035867.
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We have observed 3 nearby BY Dra systems, FK Aqr, BF Lyn, and DH Leo, with the EUVE spectrometers. All 3 show evidence of high-temperature (~ 107 K) plasma; FK Aqr and DH Leo show significant variability in their Deep Survey lightcurves. In FK Aqr, spectral differences between its “quiescent” and “active” states suggest possible differences in the plasma density. In DH Leo, the Deep Survey lightcurve, taken over nearly 8 days, shows a distinct period of ~ 1.05 days, consistent with the photometric period. The emission measure distributions of all three systems are rather similar in shape, and can be well-represented by a power law with slope ~ 1.5 from 6.2–7.0 in log T.
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Fitoussi, F. "AQM et membre supérieur." Revue de Chirurgie Orthopédique et Réparatrice de l'Appareil Moteur 91, no. 5 (2005): 192–93. http://dx.doi.org/10.1016/s0035-1040(05)84430-7.
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Mouchet, Martine, Jean-Marc Bonnet-Bidaud, Evelyne Roueff, et al. "Far-UV FUSE Spectra of Peculiar Magnetic Cataclysmic Variables." International Astronomical Union Colloquium 190 (2004): 142–48. http://dx.doi.org/10.1017/s0252921100001974.
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AbstractWe present far-UV spectra of the three magnetic cataclysmic variables (MCVs) BY Cam, V1309 Ori and AE Aqr obtained with the FUSE satellite. These MCVs have revealed strongly unusual NV and CIV UV resonance lines. The FUSE spectra exhibit broad OVI lines as well as a strong NIII line at 991Å, while the CIII 1175Å line is nearly absent, supporting non-solar CNO abundances of the accreting matter in these sources. The spectrum of BY Cam shows molecular H2 lines which might be of circumstellar nature. The flaring activity of AE Aqr is also observed in the far-UV range. The radial velocities of the broad OVI components in AE Aqr are orbitally modulated and would indicate an emission region close to the magnetosphere.
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Torkelsson, Ulf. "The submillimeter properties of AE Aqr." Proceedings of the International Astronomical Union 8, S290 (2012): 145–48. http://dx.doi.org/10.1017/s1743921312019400.
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AbstractAE Aqr is a cataclysmic variable consisting of a magnetised white dwarf with a spin period of 33 s, and a K-dwarf companion. Because of the rapid spin the magnetosphere of the white dwarf the matter that is flowing over from the secondary cannot accrete onto the white dwarf, and rather it is ejected from the system. AE Aqr is subject to extended flaring activity at all wavelengths from radio via optical to X-rays. I present observations of AE Aqr at 345 and 850 GHz using the LABOCA and SABOCA bolometers on APEX. These observations are good enough to distinguish individual flares at both 345 and 850 GHz, and the SABOCA observation is the first measurement of the system at 850 GHz.
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Schwarz, Hugo E., and Colin Aspin. "Spectroscopy and polarimetry of the R Aquarii system." Symposium - International Astronomical Union 122 (1987): 471–73. http://dx.doi.org/10.1017/s0074180900157067.
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Optical spectroscopy is used to derive the electron temperature and density of the jet of R Aqr. We present polarimetric data which shows that the degree of polarization in R Aqr can vary by up to two orders of magnitude and that this variation is correlated with the phase of the Mira. The polarization angle also varies with the phase of observation.
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Domański, Adam, Joanna Domańska, Tadeusz Czachórski, and Jerzy Klamka. "The use of a non-integer order PI controller with an active queue management mechanism." International Journal of Applied Mathematics and Computer Science 26, no. 4 (2016): 777–89. http://dx.doi.org/10.1515/amcs-2016-0055.
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AbstractIn this paper the performance of a fractional order PI controller is compared with that of RED, a well-known active queue management (AQM) mechanism. The article uses fluid flow approximation and discrete-event simulation to investigate the influence of the AQM policy on the packet loss probability, the queue length and its variability. The impact of self-similar traffic is also considered.
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Beskrovnaya, Nina, Nazar Ikhsanov, Albert Bruch, and Nikolaj Shakhovskoy. "UBVRI Photometry of AE Aquarii in July-August 1994." International Astronomical Union Colloquium 151 (1995): 276–77. http://dx.doi.org/10.1017/s025292110003517x.
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The most striking feature of the close binary system AE Aqr is its unique photometric behaviour - irregular alternations of quiet and active phases without noticeable transition periods. Although extensive photometric observations of AE Aqr have been carried out for more than forty years (see Bruch 1991 and references therein), the mechanism of its flaring activity is still poorly understood and the star - although generally classified as a cataclysmic variable - does not fit well into any of the subclasses.According to us, much insight into this peculiar object can be gained by an investigation of the connections between the flaring activity of AE Aqr and the strictly periodic oscillations at 33s, identified as the spin period of the primary. The latter have been seen in optical (Patterson 1979) and UV light (Eracleous et al. 1994), in X-rays (Patterson et al. 1980) and in TeV γ rays (Meintjes et al. 1992). There are contradictory reports about the relation between their amplitude and the flaring activity in AE Aqr: Patterson (1979) noted that the amplitude of the pulsations increases during active phases, while Eracleous et al. (1994) observed that their characteristics are not strongly affected by the flares.
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Hanniya, Akram. "The day Ibrahim Al-Aqra was killed." Index on Censorship 15, no. 9 (1986): 36–37. http://dx.doi.org/10.1080/03064228608534161.
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González, Ernesto, Juan Casanova-Chafer, Alfonso Romero, Xavier Vilanova, Jan Mitrovics, and Eduard Llobet. "LoRa Sensor Network Development for Air Quality Monitoring or Detecting Gas Leakage Events." Sensors 20, no. 21 (2020): 6225. http://dx.doi.org/10.3390/s20216225.
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During the few last years, indoor and outdoor Air Quality Monitoring (AQM) has gained a lot of interest among the scientific community due to its direct relation with human health. The Internet of Things (IoT) and, especially, Wireless Sensor Networks (WSN) have given rise to the development of wireless AQM portable systems. This paper presents the development of a LoRa (short for long-range) based sensor network for AQM and gas leakage events detection. The combination of both a commercial gas sensor and a resistance measurement channel for graphene chemoresistive sensors allows both the calculation of an Air Quality Index based on the concentration of reducing species such as volatile organic compounds (VOCs) and CO, and it also makes possible the detection of NO2, which is an important air pollutant. The graphene sensor tested with the LoRa nodes developed allows the detection of NO2 pollution in just 5 min as well as enables monitoring sudden changes in the background level of this pollutant in the atmosphere. The capability of the system of detecting both reducing and oxidizing pollutant agents, alongside its low-cost, low-power, and real-time monitoring features, makes this a solution suitable to be used in wireless AQM and early warning systems.
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Usmani, Raja Sher Afgun, Wan Nurul Farah Binti Wan Azmi, Akibu Mahmoud Abdullahi, Ibrahim Abaker Targio Hashem, and Thulasyammal Ramiah Pillai. "A novel feature engineering algorithm for air quality datasets." Indonesian Journal of Electrical Engineering and Computer Science 19, no. 3 (2020): 1444. http://dx.doi.org/10.11591/ijeecs.v19.i3.pp1444-1451.
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<span>Feature engineering (FE) is one of the most important steps in data science research. FE provides useful features to be used later in the study. Due to climate change, the research focus is moving towards air quality estimation and the impacts of air pollution on health in Malaysia. Malaysia has 66 air quality monitoring (AQM) stations, and the air quality data for research is provided in an excel worksheet format by the Department of Environment, Malaysia. The data generated by the AQM stations is in a raw custom format, and it is virtually impossible to clean and engineer this data manually due to the sheer number of files. Hence, we propose a novel feature engineering algorithm to transform and combine this data into a useable format. The results show that the proposed feature engineering algorithm was able to efficiently extract and combine the hourly and daily values for pollutant and meteorological variables in useful row format. This algorithm will help all the researchers using the data from the AQM station in Malaysia as well as other countries using the same AQM station. The implementation of the feature engineering algorithm is also available to use at GitHub (https://github.com/rajasherafgun/featureengineeringaq) under AFL-3.0 license.</span>
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Abualhaj, Mosleh M., Mayy M. Al-Tahrawi, Abdelrahman H. Hussein, and Sumaya N. Al-Khatib. "Fuzzy-Logic Based Active Queue Management Using Performance Metrics Mapping into Multi-Congestion Indicators." Cybernetics and Information Technologies 21, no. 2 (2021): 29–44. http://dx.doi.org/10.2478/cait-2021-0017.
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Abstract The congestion problem at the router buffer leads to serious consequences on network performance. Active Queue Management (AQM) has been developed to react to any possible congestion at the router buffer at an early stage. The limitation of the existing fuzzy-based AQM is the utilization of indicators that do not address all the performance criteria and quality of services required. In this paper, a new method for active queue management is proposed based on using the fuzzy logic and multiple performance indicators that are extracted from the network performance metrics. These indicators are queue length, delta queue and expected loss. The simulation of the proposed method show that in high traffic load, the proposed method preserves packet loss, drop packet only when it is necessary and produce a satisfactory delay that outperformed the state-of-the-art AQM methods.
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Moreno-Terrazas, R., H. Reyes-Morales, S. Huerta-Ochoa, I. Guerrero-Legarreta, and E. J. Vernon-Carter. "Note. Consumer Awareness of the Main Sensory Attributes of Tepache, a Traditional Fermented Fruit Beverage." Food Science and Technology International 7, no. 5 (2001): 411–15. http://dx.doi.org/10.1106/buhf-kmgc-aq4m-3rxr.
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Four tepache samples (a traditional fermented fruit beverage) from four different sources obtained by different fermentation processes were sensory evaluated. A paired comparison test between the samples was carried out in a monadic sequential fashion in six sessions with 70 consumers each. A sample processed by double fermentation received the highest mean scores for the first impression and overall acceptance and in the sensory attributes of appearance, consistency, odor, flavor and sweetness/sourness ratio. Principal component analysis indicated that appearance, odor, flavor, first impression and overall acceptance are highly intercorrelated. That sample was also the most preferred beverage in the comparative test. Flavor intensity was significantly different in all of the paired comparisons. No significant differences were found in the overall acceptance evaluations between genders. A fairly good correlation was found between overall acceptance and consumers who drank the beverage once a week.
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Schwope, A., V. Hambaryan, A. Staude, et al. "Multiwavelength observations of eclipsing polars." International Astronomical Union Colloquium 190 (2004): 92–105. http://dx.doi.org/10.1017/s0252921100001901.
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AbstractMultiwavelength observations of polars are essential for developing the big picture of these systems, particularly to gain understanding of the relevant accretion-induced heating and cooling processes. Eclipsing polars are prime targets for such studies since different radiation processes can be disentangled by observations with high-time resolution. We present a preliminary combined analysis of space-based observations (XMM-Newton, ROSAT, HST) with ground-based high-speed photometry (MCCP, OPTIMA, ULTRACAM) of DP Leo, HU Aqr and UZ For. We determine the location and extent of different emission components and find secular and short-term changes in the accretion geometries. We find displaced optical and X-ray emission regions in DP Leo and HU Aqr as well as mini-bursts and accretion arcs of variable size in HU Aqr. We report marked changes in the X-ray eclipse length of UZ For between high and low states.
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Fu, Jian Ning. "Period Variations and Binary Hypotheses of Three δ Scuti stars: CY Aqr, BS Aqr, AD CMi". International Astronomical Union Colloquium 176 (2000): 475–76. http://dx.doi.org/10.1017/s0252921100058504.
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AbstractSome new times of light maxima for three δ Scuti stars – CY Aqr, BS Aqr and AD CMi – have been determined based on new photoelectric photometry. Incorporated with the times presented in the literature, the O–C method is used to study the period variations of these stars with a newly-developed program OMC. The results reveal that for these three stars, the binary hypothesis concerning a low mass companion is reasonable in explaining the O–C diagrams.
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Pope, R. J., N. H. Savage, M. P. Chipperfield, C. Ordóñez, and L. S. Neal. "The influence of synoptic weather regimes on UK air quality: regional model studies of tropospheric column NO<sub>2</sub>." Atmospheric Chemistry and Physics Discussions 15, no. 13 (2015): 18577–607. http://dx.doi.org/10.5194/acpd-15-18577-2015.
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Abstract. Synoptic meteorology can have a significant influence on UK air quality. Cyclonic (anticyclonic) conditions lead to the dispersion (accumulation) of air pollutants away from (over) source regions. Meteorology also modifies atmospheric chemistry processes such as photolysis and wet deposition. Previous studies have shown a relationship between observed satellite tropospheric column NO2 and synoptic meteorology in different seasons. Here, we test whether the UK Met Office Air Quality in the Unified Model (AQUM) can reproduce these observations and then use the model to determine the controlling factors. We show that AQUM successfully captures the observed relationships, when sampled under the Lamb Weather Types, an objective classification of midday UK circulation patterns. By using a range of idealised NOx-like tracers with different e-folding lifetimes, we show that under different synoptic regimes the NO2 lifetime in AQUM is approximately 6 h in summer and 12 h in winter. The longer lifetime can explain why synoptic spatial column NO2 variations are more significant in winter compared to summer, due to less NO2 photochemical loss. We also show that cyclonic conditions have more seasonality in column NO2 than anticyclonic conditions as they result in more extreme spatial departures from the wintertime seasonal average. Within a season (summer or winter) under different synoptic regimes, a large proportion of the spatial pattern in the UK column NO2 field can be explained by the idealised model tracers, showing that transport is an important factor in governing the variability of UK air quality on seasonal synoptic timescales.
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Mahawish, Amar A., and Hassan J. Hassan. "Survey on: A variety of AQM algorithm schemas and intelligent techniques developed for congestion control." Indonesian Journal of Electrical Engineering and Computer Science 23, no. 3 (2021): 1419. http://dx.doi.org/10.11591/ijeecs.v23.i3.pp1419-1431.
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The congestion on the internet is the main issue that affects the performance of transition data over the network. An algorithm for congestion control is required to keep any network efficient and reliable for transfer traffic data of the users. Many Algorithms had been suggested over the years to improve the control of congestion that occurs in the network such as drop tail packets. Recently there are many algorithms have been developed to overcome the drawback of the drop tail procedure. One of the important algorithms developed is active queue management (AQM) that provides efficient congestion control by reducing drop packets, this technique considered as a base for many other congestion control algorithms schema. It works at the network core (router) for controlling the drop and marking of packets in the router's buffer before the congestion inception. In this study, a comprehensive survey is done on the AQM Algorithm schemas that proposed and modification these algorithms to achieve the best performance, the classification of AQM algorithms based on queue length, queue delay, or both. The advantages and limitations of each algorithm have been discussed. Also, debate the intelligent techniques procedure with AQM algorithm to achieve optimization in performance of algorithm operation. Finally, the comparison has been discussed among algorithms to find the weakness and powerful of each one based on different metrics.
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De los Ríos, César. "Contribución al estudio de la electrografía en la altura." Anales de la Facultad de Medicina 32, no. 2 (2014): 115. http://dx.doi.org/10.15381/anales.v32i2.9571.
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Se estudiaron en 30 electrocardiogramas de sujetos normales, nativos de la altura y residentes en Huancayo, del sexo masculino y con edades que fluctuaban entre 17 y 27 años: la forma, sentido y valores de las diferentes ondas, segmentos e intervalos, el eje eléctrico medio manifiesto de QRS y de T, el gradiente ventricular, el ángulo diferencial los índices de White-Bock, Sodi-Pallares y Goldberger, el tiempo de aparición de la deflexión intrínseca en las unipolares precordiales, el tiempo de aparición de la deflexión intrinsecoide en las derivaciones standard y unipolares de los miembros y la posición eléctrica del corazón. Las observaciones hechas son en suma las siguientes: 1° La onda P tiene amplitudes medias comprendidas dentro de límites normales pero menores que las señaladas en México. (2.400 mts.), excepto en aVR. 2° La onda Q presenta amplitudes medias dentro de límites normales. En aVR presenta un valor que se acerca a los límites superiores normales. 3° La onda R tiene amplitudes medias comprendidas dentro de límites normales pero menores que las señaladas en México y a nivel del mar; excepto en aVR en las que su amplitud es mayor. 4° La onda S presenta amplitudes medias dentro de límites normales. Las variaciones respecto a las señaladas a nivel del mar y en México, son: Superiores en: DI. DII, DIII, aVL, V4, V5 y V6. Inferiores en: aVR, VI. V2, V3, y VE. 5° La onda T presente amplitudes medias comprendidas en los límites normales pero algo mayores que los señalados en México y a nivel del mar, especialmente en DI. En DIII su valor fue inferior a los antes mencionados. 6° El Segmento ST se presenta desviado hacia arriba dentro de límites normales en las derivaciones precordiales, principalmente en V2 y V3 (100%) y en 1 (97%). Sólo en dos casos en V2 y en uno en V3 llegaron a 3mm. 7° La magnitud media de AQRS es inferior a la normal. 8° La magnitud media de AQRS es menor cuando ocupa los sextantes Nos. 4 y 5. 9° La magnitud media de AQRS es menor en las posiciones verticales y semiverticales que en las horizontales. 10° El eje eléctrico medio manifiesto de AQRS se localizó de preferencia en los sextantes Nos. 1 y 6 del sistema de referencia triaxial de Bayley. Un buen grupo ocupó el sexante N° 5. 11° Se apreció concordancia entre la dirección de AQRS y la posición eléctrica del corazón, correspondiendo a las verticales direcciones a la derecha de 90° y a las horizontales a la izquierda de 0°. 12° La magnitud media de AT fue superior a la normal. 13° La magnitud media de AT varía en función de su situación en el sistema de referencia triaxal de Bayley. Fue apreciablemente mayor cuando ocupó el sextante N° 6, que cuando se situó en el N° 1. 14° La magnitud media de AT no guarda relación con la posición eléctrica del corazón. 15° AT ocupó de preferencia el sextante N° 6. 16° La magnitud media de G tuvo casi el mismo valor que el señalado como normal. 17° La magnitud de G varía en función de su situación en el Sistema de Referencia triaxial de Bayley, siendo bastante mayor cuando ocupa el sextante N° 6, que cuando se sitúa en el N° 1. 18° G ocupó de preferencia el sextante N° 6. 19° El ángulo diferencial fue mayor de 60° cuando AQRS ocupó los sextantes Nos. 1, 2, 3 y 4. Fue menor de 60° cuando AQRS ocupó los sextantes Nos. 5 y 6 y la parte próxima del sextante N° 1. 20° Los índices de White-Block, Sodi-Pallares y Goldberger, estuvieron dentro de límites normales en todos los casos. 21° El tiempo de aparición de la deflexión intrínseca fue en todos los casos. 22° El tiempo de aparición de la deflexión instrinsecoide fue normal en todos los casos. 23° La posición eléctrica horizontal (37%) predomina discretamente sobre la vertical (30%). 24° Se encuentra un 57% de casos con rotación de la punta hacia atrás.
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Eracleous, M., K. Horne, M. Livio, and W. F. Welsh. "The Flares of AE Aqr." International Astronomical Union Colloquium 158 (1996): 165–66. http://dx.doi.org/10.1017/s0252921100038513.
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AbstractThe enigmatic flaring activity of AE Aqr, which extends from the radio to the X-ray bands, may be the exotic outcome of a relatively feeble accretion flow onto the rapidly spinning white dwarf. We summarize and interpret the results of recent observations by HST and ROSAT of the aperiodic flares. Optical and UV flares are tightly correlated and are clearly involved in powering the emission lines. The spectrum of a flare consists of a Balmer continuum, and a plethora of emission lines, which vary synchronously. The large optical/UV flares are not accompanied by large X-ray outbursts. The radial velocity curves of the UV lines, and of Hα, suggest that they originate in the accretion stream. The observational results dis-favor scenarios invoking coronal activity on the secondary star or instabilities at the disk/magnetosphere interface. Rather, they support a recently proposed scenario in which the accretion flow consists of blobs which are shocked upon encountering the white dwarf magnetosphere.
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Dutta, Debojyoti, Ashish Goel, and John Heidemann. "Oblivious AQM and nash equilibria." ACM SIGCOMM Computer Communication Review 32, no. 3 (2002): 20. http://dx.doi.org/10.1145/571697.571709.
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Wadhwa, Surjit S., and William J. Zealey. "Photometric analysis of EL Aqr." Astrophysics and Space Science 291, no. 1 (2004): 21–25. http://dx.doi.org/10.1023/b:astr.0000029933.12292.2a.
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Bhandarkar, Sumitha, A. L. Narasimha Reddy, Yueping Zhang, and Dimitri Loguinov. "Emulating AQM from end hosts." ACM SIGCOMM Computer Communication Review 37, no. 4 (2007): 349–60. http://dx.doi.org/10.1145/1282427.1282420.
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Parés, M. E., D. Garcia, and F. Vázquez-Gallego. "MAPPING AIR QUALITY WITH A MOBILE CROWDSOURCED AIR QUALITY MONITORING SYSTEM (C-AQM)." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B4-2020 (August 25, 2020): 685–90. http://dx.doi.org/10.5194/isprs-archives-xliii-b4-2020-685-2020.
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Abstract. World cities are currently facing one of the major crisis of the last century. Some preliminary studies on COVID-19 pandemia have shown that air pollutants may have a strong impact on virus effects. Improved gas sensors and wireless communication systems open the door to the design of new air monitoring systems based on citizen science to better monitor and communicate the air quality levels. In this paper, we present the Crowdsourced Air Quality Monitoring (C-AQM) system, which relies on Air Quality Monitoring reference stations and a cluster of new low-cost and low-energy sensor nodes, in order to improve the resolution of air quality maps. The data collected by the C-AQM system is stored in a time series database and is available both to city council managers for decision making and to citizens for informative purposes. In this paper, we present the main bases of the C-AQM system as well as the measurements validation campaign carried out.
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Santos, Carlos Eduardo Maffini, Carlos Alexandre Gouvea da Silva, and Carlos Marcelo Pedroso. "Improving Perceived Quality of Live Adaptative Video Streaming." Entropy 23, no. 8 (2021): 948. http://dx.doi.org/10.3390/e23080948.
Full textAbstract:
Quality of service (QoS) requirements for live streaming are most required for video-on-demand (VoD), where they are more sensitive to variations in delay, jitter, and packet loss. Dynamic Adaptive Streaming over HTTP (DASH) is the most popular technology for live streaming and VoD, where it has been massively deployed on the Internet. DASH is an over-the-top application using unmanaged networks to distribute content with the best possible quality. Widely, it uses large reception buffers in order to keep a seamless playback for VoD applications. However, the use of large buffers in live streaming services is not allowed because of the induced delay. Hence, network congestion caused by insufficient queues could decrease the user-perceived video quality. Active Queue Management (AQM) arises as an alternative to control the congestion in a router’s queue, pressing the TCP traffic sources to reduce their transmission rate when it detects incipient congestion. As a consequence, the DASH client tends to decrease the quality of the streamed video. In this article, we evaluate the performance of recent AQM strategies for real-time adaptive video streaming and propose a new AQM algorithm using Long Short-Term Memory (LSTM) neural networks to improve the user-perceived video quality. The LSTM forecast the trend of queue delay to allow earlier packet discard in order to avoid the network congestion. The results show that the proposed method outperforms the competing AQM algorithms, mainly in scenarios where there are congested networks.