423 research outputs found

    Multivariate time series classification with temporal abstractions

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    The increase in the number of complex temporal datasets collected today has prompted the development of methods that extend classical machine learning and data mining methods to time-series data. This work focuses on methods for multivariate time-series classification. Time series classification is a challenging problem mostly because the number of temporal features that describe the data and are potentially useful for classification is enormous. We study and develop a temporal abstraction framework for generating multivariate time series features suitable for classification tasks. We propose the STF-Mine algorithm that automatically mines discriminative temporal abstraction patterns from the time series data and uses them to learn a classification model. Our experimental evaluations, carried out on both synthetic and real world medical data, demonstrate the benefit of our approach in learning accurate classifiers for time-series datasets. Copyright © 2009, Assocation for the Advancement of ArtdicaI Intelligence (www.aaai.org). All rights reserved

    The effect of growth regulators on maturation, wieght, size and quality of fruit in tomato (Lycopersicon esculentum)

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    The quality of market vegetables is one of the factors that determines price and salability. In addition to quality the earliness in maturity is important for the highest profit to the grower. The effects of many synthetic growth regulating substances on flowers or vegetative structures of plants have been studied for over 30 years. During this period significant effects upon fruit set and development have been observed. The tomato was one of the vegetable crops on which chemicals were used for promoting fruit set and development. Currently, there is no concrete evidence that the regulating substances improved the quality of the tomato fruit enough to affect market acceptance. The various effects of the substances such as auxins, gibberellins, and kinins upon many species and varieties of horticultural plants will aid in understanding the nature of the morphological changes occurring during fruit set and development. The use of combinations of these substances might make it pos-sible to further investigate the effects of such growth regulators on fruit growth and development up to maturity

    Magnetic Field Uniformity Across the GF 9-2 YSO, L1082C Dense Core, and GF 9 Filamentary Dark Cloud

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    The orientation of the magnetic field (B-field) in the filamentary dark cloud GF 9 was traced from the periphery of the cloud into the L1082C dense core that contains the low-mass, low-luminosity Class 0 young stellar object (YSO) GF 9-2 (IRAS 20503+6006). This was done using SOFIA HAWC+ dust thermal emission polarimetry (TEP) at 216 um in combination with Mimir near-infrared background starlight polarimetry (BSP) conducted at H-band (1.6 um) and K-band (2.2 um). These observations were augmented with published I-band (0.77 um) BSP and Planck 850 um TEP to probe B-field orientations with offset from the YSO in a range spanning 6000 AU to 3 pc. No strong B-field orientation change with offset was found, indicating remarkable uniformity of the B-field from the cloud edge to the YSO environs. This finding disagrees with weak-field models of cloud core and YSO formation. The continuity of inferred B-field orientations for both TEP and BSP probes is strong evidence that both are sampling a common B-field that uniformly threads the cloud, core, and YSO region. Bayesian analysis of Gaia DR2 stars matched to the Mimir BSP stars finds a distance to GF 9 of 270 +/- 10 pc. No strong wavelength dependence of B-field orientation angle was found, contrary to previous claims.Comment: 18 pages, 6 figures ApJ, accepte

    Preparation of Cu3SbSe4 Doping with Aluminum and Studying on its Thermoelectrical Properties

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    في هذا البحث تمت دراسة خصائص الانتقال الكهربائي الحراري والناقلية الكهربائية للمركب AlxSe4 Cu3Sb1-x (x = 0, 0.03, 0.05 and 0.07) ولمدى من درجات الحرارة المطبقة  (298 – 553) Kوقد اظهرت النتائج  ان الزيادة في قيمة ( x = 0) to (x =0.07), زيادة في تركيز الفجوات من( 2.03×1018 الى 2.82 × 1018 cm-3) تبعا لتغير احلال او استبدال Al3+ مكان Sb5+ والذي سوف يؤدي الى نقصان كبير في قيم المقاومية الكهربائية  للمركب  Cu3Sb1-xAlxSe4، وفي نفس الوقت فان الزيادة الحاصلة في تركيز  الفجوات سوف تؤدي الى انتقال من حالة الهبوط الحاد عند (x = 0)الى النزول التدريجي او الجزئي عند(x = 0.05, 0.07) وان حالة الاستقرار ستكون عند x = 0.07))  وان عامل القدرة (PF)لكل النماذج المشوبة Cu3Sb1-xAlxSe4 ظهر هنالك تحسن فيما يخص تركيز الفجوات .وان العامل kL  ووالذي يمثل عامل التوصلية الحرارية للشبيكة يتناقص في حالة الزيادة العالية من التشويب  أي عند النموذج(x =0.07) ،وكنتيجة نهائية فان المؤشر الكبير  لقيمة  ZT = 1.28 والتي تم الحصول عليها للمركب ذو الصيغة Cu3Sb0.97Al0.03Se4   في درجة  458K, كبيرة بقدر خمسة مرات  كما لو في النموذج Cu3SbSe4والذي يمثل المركب بدون تشويبThe electrical transport and thermoelectric properties of Cu3Sb1-xAlxSe4 (x = 0, 0.03, 0.05 &0.07) compounds are investigated in the temperature range of (298 – 553) K. The results indicate that with increasing Al content from ( x = 0) to (x =0.07), hole concentration increases monotonically from (2.03×1018 to 2.82 × 1018 cm-3) due to the substitution of Al3+ for Sb5+, thus leading to a large decrease in the electrical resistivity of Cu3Sb1-xAlxSe4. Meanwhile, the increase in hole concentration leads to a transition from a non-degenerate (x = 0) to a partial degenerate (x = 0.05, 0.07) and then to a degenerate state   (x = 0.07). The power factor (PF) of all the Al-doped Cu3Sb1-xAlxSe4 samples is remarkably improved due to the optimization of hole concentration. Lattice thermal conductivity kL of the heavily doped sample(x = 0.07) is reduced. As a result, a large thermoelectric figure of merit ZT = 1.28 is obtained for Cu3Sb0.97Al0.03Se4 at 458K, which is around 5 times as large as that of the un-doped Cu3SbSe4 sample

    Gamma radiation mediated green synthesis of gold nanoparticles using fermented soybean-garlic aqueous extract and their antimicrobial activity

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    Aspergillus oryzae was used to enhance the mobilization of antioxidants of soybean matrix along with garlic as a co-substrate by modulating polyphenolic substances during solid-state fermentation. Mobilized polyphenols were used as a green tool for synthesis and stabilization of gold nanoparticles (AuNPs). The radiation-induced AuNPs synthesis is a simple, clean and inexpensive process which involves radiolysis of aqueous solution that provides an efficient method to reduce metal ions. Gamma irradiated aqueous extract of fermented soybean and garlic was used for rapid preparation of AuNPs combining both effects of radiolytic reactions by radiation and stabilization by bioactive components of fermented extract. The synthesized AuNPs were confirmed by UV-Visible spectrophotometry, dynamic light scattering (DLS), Fourier Transform infra red (FT-IR) spectrophotometry, and transmission electron microscope (TEM) analysis which revealed morphology of spherical AuNPs with size ranging from 7–12 nm. The synthesized AuNPs exhibited antimicrobial activity against both Gram positive and Gram negative bacteria, as measured by well diffusion assay

    Proper Motion of the Faint Star near KIC 8462852 (Boyajian's Star) - Not a Binary System

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    A faint star located 2 arcsec from KIC 8462852 was discovered in Keck 10 m adaptive optics imaging in the JHKJHK near-infrared (NIR) in 2014 by Boyajian et al. (2016). The closeness of the star to KIC 8462852 suggested the two could constitute a binary, which might have implications for the cause of the brightness dips seen by {\it Kepler} (Boyajian et al. (2016) and in ground-based optical studies Boyajian et al. (2018). Here, NIR imaging in 2017 using the Mimir instrument resolved the pair and enabled measuring their separation. The faint star had moved 67±767 \pm 7 milliarcsec (mas) relative to KIC 8462852 since 2014. The relative proper motion of the faint star is 23.9±2.623.9 \pm 2.6 mas yr1^{-1}, for a tangential velocity of 45±545 \pm 5 km s1^{-1} if it is at the same 390 pc distance as KIC 8462852. Circular velocity at the 750 AU current projected separation is 1.51.5 km s1^{-1}, hence the star pair cannot be bound.Comment: 10 pages, 2 figure

    Application of Pseudo-Hermitian Quantum Mechanics to a Complex Scattering Potential with Point Interactions

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    We present a generalization of the perturbative construction of the metric operator for non-Hermitian Hamiltonians with more than one perturbation parameter. We use this method to study the non-Hermitian scattering Hamiltonian: H=p^2/2m+\zeta_-\delta(x+a)+\zeta_+\delta(x-a), where \zeta_\pm and a are respectively complex and real parameters and \delta(x) is the Dirac delta function. For regions in the space of coupling constants \zeta_\pm where H is quasi-Hermitian and there are no complex bound states or spectral singularities, we construct a (positive-definite) metric operator \eta and the corresponding equivalent Hermitian Hamiltonian h. \eta turns out to be a (perturbatively) bounded operator for the cases that the imaginary part of the coupling constants have opposite sign, \Im(\zeta_+) = -\Im(\zeta_-). This in particular contains the PT-symmetric case: \zeta_+ = \zeta_-^*. We also calculate the energy expectation values for certain Gaussian wave packets to study the nonlocal nature of \rh or equivalently the non-Hermitian nature of \rH. We show that these physical quantities are not directly sensitive to the presence of PT-symmetry.Comment: 22 pages, 4 figure

    Mechanical Analysis of WEST divertor support plate

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    The Tore Supra tokamak is being transformed in an x-point divertor fusion device in the frame of the WEST (W-for tungsten-Environment in Steady-state Tokamak) project, launched in support to the ITER tungsten divertor strategy. The WEST project aims to test W monoblock Plasma Facing Units (PFU) under long plasma discharge (up to 1000s), with thermal loads of the same magnitude as those expected for ITER. Therefore the divertor is a key component of the WEST project, and so is its support structure, which has to handle strong mechanical loads. The WEST upper and lower divertor are made of 12 30° sectors, each one composed of 38 PFU that can be made of tungsten, CuCrZr or graphite. A generic 316L stainless steel 30° conic support plate is used to hold the 38 PFU together, regardless of their material. The PFUs are fixed on the support plate thanks to 152 Xm19 stainless steel fixing elements (4 per PFU), and in each of this fixing element an Aluminium-Nickel-Bronze alloy (Al-Ni-Br) pin is engaged in a slotted hole, in order to allow thermal expansion in the length direction of the PFU. The support plate is fixed on the divertor coil casing thanks to 10 M10 screws. Mechanicals loads which act on the PFUs are transmitted to the support plate through the fixing elements. These loads are due to Vertical Displacement Event (VDE), disruptions and thermal expansion of the PFU. First the different load cases, PFU configurations and scenario are presented. Then an ANSYS plastic mechanical simulation is performed in order to validate the number of cycles of the support plate for each scenario: 30 000 cycles in steady-state and 3000 cycles in VDE. Finally reactions forces from the previous ANSYS simulation are used in order to calculate the stress in the M10 screws

    Deformation Rate and Temperature Sensitivity in TWIP/TRIP VCrFeCoNi Multi-Principal Element Alloy

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    High-entropy alloys (HEAs) and medium-entropy alloys (MEAs), also sometimes referred to as multi-principal element alloys (MPEAs), present opportunities to develop new materials with outstanding mechanical properties. Through the careful selection of constituent elements along with optimized thermal processing for proper control of structure, grain size, and deformation mechanisms, many of the newly developed HEA systems exhibit superior strength and ductility levels across a wide range of temperatures, particularly at cryogenic deformation temperatures. Such a remarkable response has been attributed to the hardening capacity of many MPEAs that is achieved through the activation of deformation twinning. More recent compositions have considered phase transforming systems, which have the potential for enhanced strengthening and therefore high strength and ductility levels. However, the strain rate sensitivity of such transforming MPEAs is not well understood and requires further investigation. In this study, the tensile properties of the non-equiatomic V10Cr10Fe45Co30Ni5 MPEA were investigated at different deformation rates and temperatures ranging from 77 K (-196 degrees C) to 573 K (300 degrees C). Depending on the deformation temperature, the considered MPEA exhibits plasticity through either crystallographic slip, deformation twinning, or solid-state phase transformation. At 300 degrees C, only slip-mediated plasticity was observed for all the considered deformation rates. Deformation twinning was detected in samples deformed at room temperature, while face-centered cubic to body-centered cubic phase transformation became more favorable at cryogenic deformation temperatures. The trends are nonlinear with twinning-induced plasticity (TWIP) favored at the intermediate deformation rate, while transformation-induced plasticity (TRIP) was observed, although limited, only at the slowest deformation rate. For all the considered deformation rates at cryogenic deformation temperature, a significant TRIP activity was always detected. The extent of TRIP, however, was dependent on the deformation rate. Increasing the deformation rate is not conducive to TRIP and thus hinders the hardening capacity

    Using DHS and MICS data to complement or replace NGO baseline health data: An exploratory study

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    Background: Non-government organizations (NGOs) spend substantial time and resources collecting baseline data in order to plan and implement health interventions with marginalized populations. Typically interviews with households, often mothers, take over an hour, placing a burden on the respondents. Meanwhile, estimates of numerous health and social indicators in many countries already exist in publicly available datasets, such as the Demographic and Health Surveys (DHS) and the Multiple Indicator Cluster Surveys (MICS), and it is worth considering whether these could serve as estimates of baseline conditions. The objective of this study was to compare indicator estimates from non-governmental organizations (NGO) health projects' baseline reports with estimates calculated using the Demographic and Health Surveys (DHS) or the Multiple Indicator Cluster Surveys (MICS), matching for location, year, and season of data collection. / Methods: We extracted estimates of 129 indicators from 46 NGO baseline reports, 25 DHS datasets and three MICS datasets, generating 1,996 pairs of matched DHS/MICS and NGO indicators. We subtracted NGO from DHS/MICS estimates to yield difference and absolute difference, exploring differences by indicator. We partitioned variance of the differences by geographical level, year, and season using ANOVA. / Results: Differences between NGO and DHS/MICS estimates were large for many indicators but 33% fell within 5% of one another. Differences were smaller for indicators with prevalence 85%. Difference between estimates increased with increasing year and geographical level differences. However, <1% of the variance of the differences was explained by year, geographical level, and season. / Conclusions: There are situations where publicly available data could complement NGO baseline survey data, most importantly when the NGO has tolerance for estimates of low or unknown accuracy
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