1,005 research outputs found

    Youth Empowerment Programs in Jordan: Access and Equality

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    The research question for this study is to investigate the role of youth empowerment programs in providing equitable access for students at public and private schools in Jordan. Given the differences in education cost, quality, and outcomes between public and private schools; students are exposed to different levels of engagement opportunities within school systems. At the same time, the youth population is the engine of Jordan’s future growth. Understanding the role of external youth empowerment program providers is important to further education quality and equity. The research includes six interviews with program providers and survey results from University of Jordan. The research hypothesis is that youth empowerment programs plays a positive role in balancing, if not reducing, the education inequality seen in Jordanian society through external program provision. Upon analysis, the research concludes that although there have been major growths in the number and quality of youth empowerment programs, there are still substantial obstacles and challenges on the policy, financial, and social front that prevents further improving access to youth empowerment programs. The paper analyzes common trends among current organizations and identifies key challenges to focus on in the future. The research contributes not only to the academic literature on youth empowerment programs in Jordan, but highlights three key areas for organizations to focus on in the applied settings

    Ternary system of pyrolytic lignin, mixed solvent, and water: phase diagram and implications

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    Bio-oil from biomass fast pyrolysis is considered to be an important feedstock for the production of renewable fuels and green chemicals. Fast pyrolysis bio-oil generally contains a water-soluble fraction (excluding water), a water-insoluble fraction (i.e., pyrolytic lignin, PL), and water in a single phase. However, phase separation can occur during bio-oil transport, storage, and processing. In this study, a mixed solvent (MS) is developed based on the compositions of various fast pyrolysis bio-oils produced from a wide range of feedstocks and reactor systems. Experiments are then carried out to investigate the phase behavior of the PL/MS/water ternary system. Several ternary phase diagrams are constructed for PL and its fractions, and the PL solubilities in various MS/water mixtures are also estimated. Under the experimental conditions, the PL solubility in the MS is high, i.e., ∼112 g per 100 g of MS. In the PL/MS/water system, an increase in water content to ∼17 wt % in the MS/water mixture leads to a slight increase in the PL solubility to a maximal value of ∼118 g per 100 g of MS/water mixture, followed by a gradual decrease in the PL solubility when the water content further increases. It is found that the phase stability of the PL/MS/ water system is strongly determined by the composition of the system. For example, the PL/MS/water system is always stable when the MS content is \u3e50 wt %, while the system is always phase-separated when the PL content is \u3e54 wt %. A comparison of the results for various PL fractions indicates that the molecular weight of PL can affect the ternary phase diagram, with the PL of a lower molecular weight having a higher solubility in the same MS/water mixture. The presence of free sugar (i.e., levoglucosan, present in bio-oil as solute) also influences the ternary phase diagram of the PL/MS/system, but only at a low water content (i.e., \u3c 20 wt %). The results suggest that such ternary diagrams may be potentially an important tool for predicting the phase separation of bio-oil, as a result of changes in the bio-oil chemistry in various processes (e.g., cold-water precipitation and aging). Please click Additional Files below to see the full abstract

    Durability of Composite-Modified Asphalt Mixture Based on Inherent and Improved Performance

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    The composite performance of modified asphalt and composite-modified asphalt mixture (CMAM) is divided into inherent performance and improved performance. The inherent performance refers to the original performance of the virgin asphalt and asphalt mixture. The improved performance refers to the performance obtained by modifying the virgin asphalt. In the study, the modified asphalt and asphalt mixture were tested through a series of experiments. The antiaging durability of the modified asphalt is explored based on the inherent performance and improved performance at high and low temperatures. The antiaging durability of the modified asphalt mixture is explored based on the inherent performance and improved performance at the mechanical performance. Meanwhile, based on inherent and improved performances, this chapter uses three kinds of CMAM (4% SBS/3% SBR, 4% SBS/15% rubber, and 4% SBR/15% rubber) as research objects to test the change rule of mechanical properties. This chapter outlines CMAM design, mechanical property tests, and comparative durability analysis

    Convergence Theory of Learning Over-parameterized ResNet: A Full Characterization

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    ResNet structure has achieved great empirical success since its debut. Recent work established the convergence of learning over-parameterized ResNet with a scaling factor τ=1/L\tau=1/L on the residual branch where LL is the network depth. However, it is not clear how learning ResNet behaves for other values of τ\tau. In this paper, we fully characterize the convergence theory of gradient descent for learning over-parameterized ResNet with different values of τ\tau. Specifically, with hiding logarithmic factor and constant coefficients, we show that for τ1/L\tau\le 1/\sqrt{L} gradient descent is guaranteed to converge to the global minma, and especially when τ1/L\tau\le 1/L the convergence is irrelevant of the network depth. Conversely, we show that for τ>L12+c\tau>L^{-\frac{1}{2}+c}, the forward output grows at least with rate LcL^c in expectation and then the learning fails because of gradient explosion for large LL. This means the bound τ1/L\tau\le 1/\sqrt{L} is sharp for learning ResNet with arbitrary depth. To the best of our knowledge, this is the first work that studies learning ResNet with full range of τ\tau.Comment: 31 page

    The Davis-Gut law for independent and identically distributed Banach space valued random elements

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    An analog of the Davis-Gut law for a sequence of independent and identically distributed Banach space valued random elements is obtained, which extends the result of Li and Rosalsky (A supplement to the Davis-Gut law. J. Math. Anal. Appl. 330 (2007), 1488-1493)

    Dynamic analysis of ground steering response of aircraft with electric taxi system

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    To provide taxi capability without the use of engines or tractor, electric landing gear drive is considered as a potential system add-on. Driving torque and nose wheel steering angle controller are established which are verified by civil aircraft examples. Quasi-steady method is applied to calculate tire forces and moments. The ground steering response of aircraft is simulated, and then different taxi conditions including powered nose wheel mode and powered main wheel mode are compared. Two conclusions are obtained: Electric taxi system helps the aircraft turn on the spot and the turning radius is smaller than the aircraft using engines; differential powered main wheel mode has the minimum turning radius while turning-circle with uniform velocity, and it has smaller difference between two vertical loads of main landing gear than powered nose wheel mode