490 research outputs found

    Towards Enhancing Traffic Sign Recognition through Sliding Windows

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    Automatic Traffic Sign Detection and Recognition (TSDR) provides drivers with critical information on traffic signs, and it constitutes an enabling condition for autonomous driving. Misclassifying even a single sign may constitute a severe hazard, which negatively impacts the environment, infrastructures, and human lives. Therefore, a reliable TSDR mechanism is essential to attain a safe circulation of road vehicles. Traffic Sign Recognition (TSR) techniques that use Machine Learning (ML) algorithms have been proposed, but no agreement on a preferred ML algorithm nor perfect classification capabilities were always achieved by any existing solutions. Consequently, our study employs ML-based classifiers to build a TSR system that analyzes a sliding window of frames sampled by sensors on a vehicle. Such TSR processes the most recent frame and past frames sampled by sensors through (i) Long Short-Term Memory (LSTM) networks and (ii) Stacking Meta-Learners, which allow for efficiently combining base-learning classification episodes into a unified and improved meta-level classification. Experimental results by using publicly available datasets show that Stacking Meta-Learners dramatically reduce misclassifications of signs and achieved perfect classification on all three considered datasets. This shows the potential of our novel approach based on sliding windows to be used as an efficient solution for TSR

    Meta-learning to improve unsupervised intrusion detection in cyber-physical systems

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    Fed batch production of hydrogen from palm oil mill effluent using anaerobic microflora

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    Anaerobic production of hydrogen from palm oil mill effluent (POME) by microflora was investigated in 5-l bioreactor at 60 °C and pH 5.5. POME sludge was collected from the anaerobic pond of a POME treatment plant at a palm oil mill and used as a source of inocula. A batch reactor was found to yield a total of 4708 ml H2H2/(l POME) and the maximum evolution rate was 454 ml-H2H2/(l POME h). A fed batch process was conducted after 50 h. Two liters of reaction medium was removed and 2 l of fresh POME was added to the reactor every 24 h (15 times). The reproducibility of the fed batch process checked by changing the feeding time every 8 h (10 times). A yield of 2382 ml H2H2/(l POME) and 2419 ml H2H2/(l POME) at maximum evolution rate of 313 ml H2H2/(l POME h) and 436 ml H2H2/(l POME h) were obtained, respectively. Throughout the study, methane gas was not observed in the evolved gas mixture

    Evaluation of Immune Response to Hepatitis B Vaccine among Malnourished Children in Yemen

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    Objectives: To determine the coverage rate of hepatitis B virus (HBV) vaccine and to evaluate the immune response to HBV vaccine by measuring hepatitis B surface antibody (anti-HBs) among malnourished under-five-year old children.Methods: A cross-sectional study was conducted in two tertiary hospitals in Yemen; Al-Sabeen Maternity and Child Hospital in Sana’a and the Yemeni-Swedish Hospital in Taiz city in the period from March 2014 to Dec. 2014. The target population was malnourished children aged from 6 to 59 months old with a history of three HBV vaccine doses in infancy. According to the World Health Organization’s definition of malnutrition, 121 malnourished children were enrolled in the study. Data of malnourished children were collected using a pre-designed, pre-tested questionnaire. Two milliliters of venous blood were taken, and anti-HBs was then tested by enzyme linked immunosorbent assay. An anti-HBs level of at least 10 IU/L was considered a successful response to the vaccine.Results: The coverage rate of HBV vaccine among malnourished children was 89.3%, being higher among girls (52.1%) than boys (37.2%). Response to HBV vaccine (≥10 IU/L) was observed in 72.2% (78/108) of children while 27.8% (30/108) of children failed to respond to the vaccine, with a statistically significant difference (p <0.001).Conclusions: A good HBV vaccine coverage rate was found among malnourished Yemeni children, with a moderate rate of protection. Therefore, re-vaccination or administration of booster doses to a substantial proportion of vaccinated children should be considered

    Minimizing Thermal Stress for Data Center Servers through Thermal-Aware Relocation

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    A rise in inlet air temperature may lower the rate of heat dissipation from air cooled computing servers. This introduces a thermal stress to these servers. As a result, the poorly cooled active servers will start conducting heat to the neighboring servers and giving rise to hotspot regions of thermal stress, inside the data center. As a result, the physical hardware of these servers may fail, thus causing performance loss, monetary loss, and higher energy consumption for cooling mechanism. In order to minimize these situations, this paper performs the profiling of inlet temperature sensitivity (ITS) and defines the optimum location for each server to minimize the chances of creating a thermal hotspot and thermal stress. Based upon novel ITS analysis, a thermal state monitoring and server relocation algorithm for data centers is being proposed. The contribution of this paper is bringing the peak outlet temperatures of the relocated servers closer to average outlet temperature by over 5 times, lowering the average peak outlet temperature by 3.5% and minimizing the thermal stress

    A novel sensorless control for multiphase induction motor drives based on singularly perturbed sliding mode observer-experimental validation

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    This paper aims to develop an innovative sensorless control approach for a five-phase induction motor (IM) drive. The operation principle of the sensorless scheme is based on the sliding mode theory, within which a sliding mode observer (SMO) estimates the speed and rotor resistance simultaneously. The operation methodology of the proposed control technique is formulated using the mathematical model of the machine and the two-time-scale approach. The observation technique offers a simple and robust solution of speed and rotor resistance estimation for the sensorless control approach of the multiphase drive. The paper considers the five-phase induction motor (IM) as a case study; however, the proposed control algorithm can be employed by different types of multiphase machines. To test the applicability of the proposed sensorless control approach, the drive performance is firstly validated using MATLAB/Simulink-based simulation. Then, the simulation results are verified using real-time simulation and experimentally using TMS320C32 DSP-based control board. The obtained results confirm and validate the ability of the proposed control procedure in achieving a robust dynamic performance of the drive against the system uncertainties such as parameter variation.This research was supported by department of electrical engineering and computer science, Khalifa University, Abu Dhabi 127788, UAE.Scopu

    On handovers in uplink/downlink decoupled LTE HetNets

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    Cellular heterogeneous networks (HetNets) are going to be one of the key enablers for 5G. Downlink/Uplink decoupling (DUDe) is a concept in which a mobile device is connected with Macro cell for downlink communication and with small cell for uplink communication in LTE/LTE-A HetNets. It improves uplink data rate, reduces power consumption of devices, balances load between Macro cell and small cells. Due to incorporation of DUDe, a mobile device has to perform separate uplink and downlink handovers unlike traditional handovers in coupled LTE networks. In this paper, we propose various handover schemes for DUDe LTE networks. Apart from this, we have mathematically analysed the received SINR by small cells taken part in decoupling, with respect to a device moving in decoupling regions of these small cells, in multiple cell interference scenario. Simulation results show the signaling impact of DUDe in handovers, increased uplink SINR, decreased power consumption of devices in both single small cell and multiple small cell scenarios

    Children’s services in the age of information technology: What matters most to frontline professionals

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    Summary The last two decades have seen information systems featuring prominently in calls for the modernisation of the UK social care system. However, critics have maintained that these systems are of limited value to social care professionals whose design and implementation is driven by a preoccupation with performance management and a culture of professional audit and accountability, precepts of 'managerialism'. However, this area of research has often suffered from lack of focus on how technological changes affect public administration and service delivery and often characterises technology as a politically neutral tool detached from its socio-political context whilst also ignoring the strategic predispositions of human service professionals.Findings This research was conducted in three local authorities in England. Using the 'technological affordance' perspective, we contend that the way social workers interact with Integrated Children's System is shaped by the discord between socio-historically evolved professional values epitomising the social work profession and managerialist reforms promoting standardised ways of performing it. Application Integrated Children's System has transformed social work from an art to a technical activity, dominated by unimaginative and routinised working practices. Social workers are becoming peripheral figures and this is where social work needs to be reclaimed. Policymakers need to rethink taken for granted assumptions that practitioners would replace their professional expertise with technology and realise that the effective use of Integrated Children's System depends on bureau-professionalised judgements of social workers. Whilst specific patterns of technology usage can be developed and institutionalised, real objectives of children's social services should not be sacrificed

    From music to mathematics and backwards: introducing algebra, topology and category theory into computational musicology

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    International audienceDespite a long historical relationship between mathematics and music, the interest of mathematicians is a recent phenomenon. In contrast to statistical methods and signal-based approaches currently employed in MIR (Music Information Research), the research project described in this paper stresses the necessity of introducing a structural multidisciplinary approach into computational musicology making use of advanced mathematics. It is based on the interplay between three main mathematical disciplines: algebra, topology and category theory. It therefore opens promising perspectives on important prevailing challenges, such as the automatic classification of musical styles or the solution of open mathematical conjectures, asking for new collaborations between mathematicians, computer scientists, musicologists, and composers. Music can in fact occupy a strategic place in the development of mathematics since music-theoretical constructions can be used to solve open mathematical problems. The SMIR project also differs from traditional applications of mathematics to music in aiming to build bridges between different musical genres, ranging from contemporary art music to popular music, including rock, pop, jazz and chanson. Beyond its academic ambition, the project carries an important societal dimension stressing the cultural component of 'mathemusical' research, that naturally resonates with the underlying philosophy of the “Imagine Maths”conference series. The article describes for a general public some of the most promising interdisciplinary research lines of this project

    CD4\u3csup\u3e+\u3c/sup\u3e T cells in the lungs of acute sarcoidosis patients recognize an Aspergillus nidulans epitope

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    Löfgren’s syndrome (LS) is an acute form of sarcoidosis characterized by a genetic association with HLA-DRB1*03 (HLA-DR3) and an accumulation of CD4+ T cells of unknown specificity in the bronchoalveolar lavage (BAL). Here, we screened related LS-specific TCRs for antigen specificity and identified a peptide derived from NAD-dependent histone deacetylase hst4 (NDPD) of Aspergillus nidulans that stimulated these CD4+ T cells in an HLA-DR3–restricted manner. Using ELISPOT analysis, a greater number of IFN-γ– and IL-2–secreting T cells in the BAL of DR3+ LS subjects compared with DR3+ control subjects was observed in response to the NDPD peptide. Finally, increased IgG antibody responses to A. nidulans NDPD were detected in the serum of DR3+ LS subjects. Thus, our findings identify a ligand for CD4+ T cells derived from the lungs of LS patients and suggest a role of A. nidulans in the etiology of LS
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