12,485 research outputs found
The Impact of Heterogeneous Trading Rules on the Limit Order Book and Order Flows
In this paper we develop a model of an order-driven market where traders set bids and asks and post market or limit orders according to exogenously fixed rules. Agents are assumed to have three components to the expectation of future asset returns, namely-fundamentalist, chartist and noise trader. Furthermore agents differ in the characteristics describing these components, such as time horizon, risk aversion and the weights given to the various components. The model developed here extends a great deal of earlier literature in that the order submissions of agents are determined by utility maximisation, rather than the mechanical unit order size that is commonly assumed. In this way the order flow is better related to the ongoing evolution of the market. For the given market structure we analyze the impact of the three components of the trading strategies on the statistical properties of prices and order flows and observe that it is the chartist strategy that is mainly responsible of the fat tails and clustering in the artificial price data generated by the model. The paper provides further evidence that large price changes are likely to be generated by the presence of large gaps in the book
The Research on Sensor Optimal Layout on Detection Device for Automobile Seat Horizontal Drive Mechanism
The type of the sensor and the optimal placement of the installation location of the sensor are important factors in vibration signal acquisition on automobile seat horizontal drive mechanism (HDM) for quality grading. According to the characteristics of HDM, the actual installation condition and the attenuation characteristic of the vibration signal transmission, the type of sensor was selected reasonably. By means of finite element analysis method, the best placement of the sensors to mount on the fixture was analyzed aim to maximize the information reflecting the fault and be sensitivity to the direction of the vibration. The finite element simulation and experimental results show that the acceleration sensor can effectively detect the fault characteristic signal, which provides a basis for further quality grading for HDM
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Characteristics and influence of biosmoke on the fine-particle ionic composition measured in Asian outflow during the Transport and Chemical Evolution Over the Pacific (TRACE-P) experiment
Optical Second Harmonic Generation in Anisotropic Multilayers with Complete Multireflection Analysis of Linear and Nonlinear Waves using #SHAARP.ml Package
Optical second harmonic generation (SHG) is a nonlinear optical effect widely
used for nonlinear optical microscopy and laser frequency conversion.
Closed-form analytical solution of the nonlinear optical responses is essential
for evaluating the optical responses of new materials whose optical properties
are unknown a priori. A recent open-source code, SHAARP(si), can provide such
closed form solutions for crystals with arbitrary symmetries, orientations, and
anisotropic properties at a single interface. However, optical components are
often in the form of slabs, thin films on substrates, and multilayer
heterostructures with multiple reflections of both the fundamental and up to
ten different SHG waves at each interface, adding significant complexity. Many
approximations have therefore been employed in the existing analytical
approaches, such as slowly varying approximation, weak reflection of the
nonlinear polarization, transparent medium, high crystallographic symmetry,
Kleinman symmetry, easy crystal orientation along a high-symmetry direction,
phase matching conditions and negligible interference among nonlinear waves,
which may lead to large errors in the reported material properties. To avoid
these approximations, we have developed an open-source package named Second
Harmonic Analysis of Anisotropic Rotational Polarimetry in Multilayers
(SHAARP(ml)). The reliability and accuracy are established by experimentally
benchmarking with both the SHG polarimetry and Maker fringes predicted from the
package using standard materials
A peculiauty of a jurisdical person and an educational foundation
人と法人及び学校法人の特性並びに学校との関係について論究し, その問題点を追究している。A distinctive character of a jurisdical person and an educational foundation are studiel and more the relation among school and it's focuses will be discusscd
Emerging phleboviruses
The <i>Bunyavidae</i> family is the largest grouping of RNA viruses and arguably the most diverse. Bunyaviruses have a truly global distribution and can infect vertebrates, invertebrates and plants. The majority of bunyaviruses are vectored by arthropods and thus have the remarkable capability to replicate in hosts of disparate phylogeny. The family has provided many examples of emerging viruses including Sin Nombre and related viruses responsible for hantavirus cardiopulmonary syndrome in the Americas, first identified in 1993, and Schmallenberg virus which emerged in Europe in 2011, causing foetal malformations in ruminants. In addition, some well-known bunyaviruses like Rift Valley fever and Crimean-Congo haemorrhagic fever viruses continue to emerge in new geographical locations. In this short review we focus on newly identified viruses associated with severe haemorrhagic disease in humans in China and the US
The effects of water and microstructure on the performance of polymer electrolyte fuel cells
n this paper, we present a comprehensive non-isothermal, one-dimensional model of the cathode side of a Polymer Electrolyte Fuel Cell. We explicitly include the catalyst layer, gas diffusion layer and the membrane. The catalyst layer and gas diffusion layer are characterized by several measurable microstructural parameters. We model all three phases of water, with a view to capturing the effect that each has on the performance of the cell. A comparison with experiment is presented, demonstrating excellent agreement, particularly with regard to the effects of water activity in the channels and how it impacts flooding and membrane hydration. We present several results pertaining to the effects of water on the current density (or cell voltage), demonstrating the role of micro-structure, liquid water removal from the channel, water activity, membrane and gas diffusion layer thickness and channel temperature. These results provide an indication of the changes that are required to achieve optimal performance through improved water management and MEA-component design. Moreover, with its level of detail, the model we develop forms an excellent basis for a multi-dimensional model of the entire membrane electrode assembly
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Impacts of biomass burning in Southeast Asia on ozone and reactive nitrogen over the western Pacific in spring
Aircraft measurements of ozone (O3) and its precursors (reactive nitrogen, CO, nonmethane hydrocarbons) were made over the western Pacific during the Transport and Chemical Evolution Over the Pacific (TRACE-P) campaign, which was conducted during February-April 2001. Biomass burning activity was high over Southeast Asia (SEA) during this period (dry season), and convective activity over SEA frequently transported air from the boundary layer to the free troposphere, followed by eastward transport to the sampling region over the western Pacific south of 30°N. This data set allows for systematic investigations of the chemical and physical processes in the outflow from SEA. Methyl chloride (CH3Cl) and CO are chosen as primary and secondary tracers, respectively, to gauge the degree of the impact of emissions of trace species from biomass burning. Biomass burning is found to be a major source of reactive nitrogen (NO x, PAN, HNO3, and nitrate) and O3 in this region from correlations of these species with the tracers. Changes in the abundance of reactive nitrogen during upward transport are quantified from the altitude change of the slopes of the correlations of these species with CO. NOx decreased with altitude due to its oxidation to HNO3. On the other hand, PAN was conserved during transport from the lower to the middle troposphere, consistent with its low water solubility and chemical stability at low temperatures. Large losses of HNO3 and nitrate, which are highly water soluble, occurred in the free troposphere, most likely due to wet removal by precipitation. This has been shown to be the major pathway of NOy loss in the middle troposphere. Increases in the mixing ratios of O3 and its precursors due to biomass burning in SEA are estimated using the tracers. Enhancements of CO and total reactive nitrogen (NOy), which are directly emitted from biomass burning, were largest at 2-4 km. At this altitude the increases in NOy and O3 were 810 parts per trillion by volume (pptv) and 26 parts per billion by volume (ppbv) above their background values of 240 pptv and 31 ppbv, respectively. The slope of the O3-CO correlation in biomass burning plumes was similar to those observed in fire plumes in northern Australia, Africa, and Canada. The O3 production efficiency (OPE) derived from the O3-CO slope and NOx/CO emission ratio (ER) is shown to be positively correlated with the C2H4 /NOx ER, indicating that the C2H4/NO x ER is a critical parameter in determining the OPE. Comparison of the net O3 flux across the western Pacific region and total O3 production due to biomass burning in SEA suggests that about 70% of O3 produced was transported to the western Pacific. Copyright 2004 by the American Geophysical Union
Intrinsic Correlation between Hardness and Elasticity in Polycrystalline Materials and Bulk Metallic Glasses
Though extensively studied, hardness, defined as the resistance of a material
to deformation, still remains a challenging issue for a formal theoretical
description due to its inherent mechanical complexity. The widely applied
Teter's empirical correlation between hardness and shear modulus has been
considered to be not always valid for a large variety of materials. Here,
inspired by the classical work on Pugh's modulus ratio, we develop a
theoretical model which establishes a robust correlation between hardness and
elasticity for a wide class of materials, including bulk metallic glasses, with
results in very good agreement with experiment. The simplified form of our
model also provides an unambiguous theoretical evidence for Teter's empirical
correlation.Comment: 10 pages, 4 figures and 3 table
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