522 research outputs found

    Multi-Stage Neural Networks with Application to Motion Planning of a Mechanical Snake

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    An efficient approach to nonlinear control problems in which the plant is to be driven to a desired state using a neural network controller in a number of steps is by representing the whole process as a multi - stage neural network. In this paper, an explicit formulation of the back propagation algorithm is developed for such networks. Later, this approach is used to build up a path planner for a mechanical snake (a robot composed of a sequence of articulated links). This path planner, together with a tracking algorithm, is shown to get the mechanical snake out of a collision-free closed region

    Multi-Attribute SCADA-Specific Intrusion Detection System for Power Networks

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    The increased interconnectivity and complexity of supervisory control and data acquisition (SCADA) systems in power system networks has exposed the systems to a multitude of potential vulnerabilities. In this paper, we present a novel approach for a next-generation SCADA-specific intrusion detection system (IDS). The proposed system analyzes multiple attributes in order to provide a comprehensive solution that is able to mitigate varied cyber-attack threats. The multiattribute IDS comprises a heterogeneous white list and behavior-based concept in order to make SCADA cybersystems more secure. This paper also proposes a multilayer cyber-security framework based on IDS for protecting SCADA cybersecurity in smart grids without compromising the availability of normal data. In addition, this paper presents a SCADA-specific cybersecurity testbed to investigate simulated attacks, which has been used in this paper to validate the proposed approach

    Matrix metalloproteinase-9 in broncho-alveolar lavage fluid of patients with non-small cell lung cancer

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    Aim: To evaluate concentration of MMP-9 in blood plasma and broncho-alveolar lavage fluid (BALF) from patients with non-small cell lung cancer (NSCLC). Methods: Blood рlasma from 40 NSCLC patients and 40 healthy donors was collected and concentrations of blood plasma and BALF MMP-9 were measured using ELISA. Correlation between MMP-9 level and gender, histological type of tumor and stage of disease was analyzed. Results: Levels of blood plasma MMP-9 were significantly higher in NSCLC patients (p < 0.0001) then in control group, and were especially high in patients with stage IV of disease (stage I vs stage IV — p < 0.005, stage II vs stage IV — p < 0.01, stage III vs stage IV — p < 0.01). Also, stage IV of NSCLC was characterized by the highest level of BALF MMP-9 (stage I vs stage IV — p < 0.002, stage II vs stage IV p < 0.002, and stage III vs stage IV p < 0.007). Correlation between blood plasma and BALF MMP-9 levels and gender or histological type of tumor was insignificant. Conclusion: Our data revealed significant correlation between tumor stage and BALF and plasma MMP-9 levels in NSCLC patients.Цель: определить концентрацию матриксной металлопротеиназы 9 (ММП-9) в плазме крови и бронхо-альвеолярной жидкости (БАЖ) больных немелкоклеточным раком легкого (НМКРЛ). Методы: концентрацию ММП-9 в плазме крови и БАЖ больных НМКРЛ (n = 40) и здоровых доноров (n = 40) определяли иммуноферментным методом и анализировали корреляцию этих параметров с клиническими данными (полом больного, гистологическим типом опухоли, стадией заболевания). Результаты: содержание ММП-9 в плазме крови было значительно выше у больных НМКРЛ по сравнению с контрольной группой (p < 0,0001), особенно у больных с IV стадией заболевания. Стадия IV НМКРЛ также характеризовалась наиболее высоким уровнем ММП-9 в БАЖ. Корреляции между уровнем ММП-9 в плазме крови и БАЖ, полом больного и гистологическим типом опухоли не была выявлена. Выводы: существует статистически значимая корреляция между стадией развития НМКРЛ и содержанием ММП-9 в плазме крови и БАЖ больных

    Mapping development and health effects of cooking with solid fuels in low-income and middle-income countries, 2000–18: a geospatial modelling study

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    Background More than 3 billion people do not have access to clean energy and primarily use solid fuels to cook. Use of solid fuels generates household air pollution, which was associated with more than 2 million deaths in 2019. Although local patterns in cooking vary systematically, subnational trends in use of solid fuels have yet to be comprehensively analysed. We estimated the prevalence of solid-fuel use with high spatial resolution to explore subnational inequalities, assess local progress, and assess the effects on health in low-income and middle-income countries (LMICs) without universal access to clean fuels. Methods We did a geospatial modelling study to map the prevalence of solid-fuel use for cooking at a 5 km × 5 km resolution in 98 LMICs based on 2·1 million household observations of the primary cooking fuel used from 663 population-based household surveys over the years 2000 to 2018. We use observed temporal patterns to forecast household air pollution in 2030 and to assess the probability of attaining the Sustainable Development Goal (SDG) target indicator for clean cooking. We aligned our estimates of household air pollution to geospatial estimates of ambient air pollution to establish the risk transition occurring in LMICs. Finally, we quantified the effect of residual primary solid-fuel use for cooking on child health by doing a counterfactual risk assessment to estimate the proportion of deaths from lower respiratory tract infections in children younger than 5 years that could be associated with household air pollution. Findings Although primary reliance on solid-fuel use for cooking has declined globally, it remains widespread. 593 million people live in districts where the prevalence of solid-fuel use for cooking exceeds 95%. 66% of people in LMICs live in districts that are not on track to meet the SDG target for universal access to clean energy by 2030. Household air pollution continues to be a major contributor to particulate exposure in LMICs, and rising ambient air pollution is undermining potential gains from reductions in the prevalence of solid-fuel use for cooking in many countries. We estimated that, in 2018, 205 000 (95% uncertainty interval 147 000–257 000) children younger than 5 years died from lower respiratory tract infections that could be attributed to household air pollution. Interpretation Efforts to accelerate the adoption of clean cooking fuels need to be substantially increased and recalibrated to account for subnational inequalities, because there are substantial opportunities to improve air quality and avert child mortality associated with household air pollution.This study was funded by the Bill & Melinda Gates Foundation. L G Abreu acknowledges support from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (Capes; finance Code 001), Conselho Nacional de Desenvolvimento Científico e Tecnológico, and Fundação de Amparo à Pesquisa do Estado de Minas Gerais. D A Bennett acknowledges support from the Oxford National Institute for Health Research (NIHR) Biomedical Research Centre (BRC). The views expressed are those of the author and not necessarily those of the NHS, the NIHR, or the UK Department of Health and Social Care. Z A Bhutta acknowledges support from the Institute for Global Health & Development at the Aga Khan University. F Carvalho acknowledges UID/MULTI/04378/2019 and UID/QUI/50006/2019 support with funding from FCT/MCTES through national funds. J-W De Neve is supported by the Alexander von Humboldt Foundation. S Dey acknowledges the support from the Centre of Excellence for Research on Clean Air, IIT Delhi. M Ausloos and C Herteliu are partly supported by a grant of the Romanian National Authority for Scientific Research and Innovation (project number PN-III-P4-ID-PCCF-2016-0084). C Herteliu is partly supported by a grant of the Romanian National Authority for Scientific Research and Innovation (project number PN-III-P2-2.1-SOL-2020-2-0351), the Romanian Ministry of Research Innovation and Digitalization (project number ID-585-CTR-42-PFE-2021), and the Romanian Ministry of Labour and Social Justice (30/PSCD/2018). M Jakovljevic acknowledges partial support through Grant OI 175 014 of the Ministry of Science Education and Technological Development of the Republic of Serbia. J S John acknowledges support from the Kunshan Government and China Center for Disease Control and Prevention. W Mendoza is a program analyst in population and development at the United Nations Population Fund country office in Peru, an institution that does not necessarily endorse this study. M N Khan acknowledges the support of Jatiya Kabi Kazi Nazrul Islam University, Bangladesh. K Krishan is supported by UGC Centre of Advanced Study (CAS II), awarded to the Department of Anthropology, Panjab University, Chandigarh, India. M Kumar acknowledges support (FIC/NIH funded K43 TW010716-04 study). B Lacey acknowledges support from UK Biobank, the NIHR Oxford Biomedical Research Centre, and the British Heart Foundation Oxford Centre of Research Excellence. B R Nascimento acknowledges support in part by CNPq (Bolsa de produtividade em pesquisa, 312382/2019-7), by the Edwards Lifesciences Foundation (Every Heartbeat Matters Program 2020) and by FAPEMIG (grant APQ-000627-20). A M Samy acknowledges the support from the Egyptian Fulbright Mission Program. M M Santric-Milicevic acknowledges the support of the Ministry of Education, Science and Technological Development of Serbia (contract 175087). A Sheikh acknowledges the support of Health Data Research UK. I N Soyiri acknowledges support from the University of Hull internal QR Global Challenges Research Fund. S B Zaman acknowledges receiving a scholarship from the Australian Government research training program in support of his academic career. Y Zhang was supported by Science and Technology Research Project of Hubei Provincial Department of Education (grant Q20201104) and Outstanding Young and Middle Aged Technology Innovation Team Project of Hubei Provincial Department of Education (grant T2020003).publishedVersio

    The impact of capital structure on the decision to outsource with long term contracts

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    This paper analyzes how capital structure affects the firms’ strategic choice between outsourcing with long term contracts and outsourcing to the spot market. When outsourcing to the spot market firms are exposed to price uncertainty, whereas a long term contract allows them to set in advance the outsourcing price. We show that, to the extent that leverage and uncertainty can lead to financial distress costs in bad states of nature, firms may use long term contracts as a risk management device to hedge input price uncertainty.N/

    Radial Velocity Studies of Close Binary Stars. XI

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    Radial-velocity measurements and sine-curve fits to the orbital radial velocity variations are presented for ten close binary systems: DU Boo, ET Boo, TX Cnc, V1073 Cyg, HL Dra, AK Her, VW LMi, V566 Oph, TV UMi and AG Vir. By this contribution, the DDO program has reached the point of 100 published radial velocity orbits. The radial velocities have been determined using an improved fitting technique which uses rotational profiles to approximate individual peaks in broadening functions. Three systems, ET Boo, VW LMi and TV UMi, were found to be quadruple while AG Vir appears to be a spectroscopic triple. ET Boo, a member of a close visual binary with Pvis=113P_{vis} = 113 years, was previously known to be a multiple system, but we show that the second component is actually a close, non-eclipsing binary. The new observations enabled us to determine the spectroscopic orbits of the companion, non-eclipsing pairs in ET Boo and VW LMi. The particularly interesting case is VW LMi, where the period of the mutual revolution of the two spectroscopic binaries is only 355 days. While most of the studied eclipsing pairs are contact binaries, ET Boo is composed of two double-lined detached binaries and HL Dra is single-lined detached or semi-detached system. Five systems of this group were observed spectroscopically before: TX Cnc, V1073 Cyg, AK Her (as a single-lined binary), V566 Oph, AG Vir, but our new data are of much higher quality than the previous studies.Comment: Accepted by AJ, August 2006, 10 figures, 3 table

    The Relation Between the Surface Brightness and the Diameter for Galactic Supernova Remnants

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    In this work, we have constructed a relation between the surface brightness (Σ\Sigma) and diameter (D) of Galactic C- and S-type supernova remnants (SNRs). In order to calibrate the Σ\Sigma-D dependence, we have carefully examined some intrinsic (e.g. explosion energy) and extrinsic (e.g. density of the ambient medium) properties of the remnants and, taking into account also the distance values given in the literature, we have adopted distances for some of the SNRs which have relatively more reliable distance values. These calibrator SNRs are all C- and S-type SNRs, i.e. F-type SNRs (and S-type SNR Cas A which has an exceptionally high surface brightness) are excluded. The Sigma-D relation has 2 slopes with a turning point at D=36.5 pc: Σ\Sigma(at 1 GHz)=8.46.3+19.5^{+19.5}_{-6.3}×1012\times10^{-12} D5.990.33+0.38^{{-5.99}^{+0.38}_{-0.33}} Wm2^{-2}Hz1^{-1}ster1^{-1} (for Σ\Sigma3.7×1021\le3.7\times10^{-21} Wm2^{-2}Hz1^{-1}ster1^{-1} and D\ge36.5 pc) and Σ\Sigma(at 1 GHz)=2.71.4+2.1^{+2.1}_{-1.4}×\times 1017^{-17} D2.470.16+0.20^{{-2.47}^{+0.20}_{-0.16}} Wm2^{-2}Hz1^{-1}ster1^{-1} (for Σ\Sigma>3.7×1021>3.7\times10^{-21} Wm2^{-2}Hz1^{-1}ster1^{-1} and D<<36.5 pc). We discussed the theoretical basis for the Σ\Sigma-D dependence and particularly the reasons for the change in slope of the relation were stated. Added to this, we have shown the dependence between the radio luminosity and the diameter which seems to have a slope close to zero up to about D=36.5 pc. We have also adopted distance and diameter values for all of the observed Galactic SNRs by examining all the available distance values presented in the literature together with the distances found from our Σ\Sigma-D relation.Comment: 45 pages, 2 figures, accepted for publication in Astronomical and Astrophysical Transaction
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