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61.
Forecasting and trading the EUR/USD exchange rate with Gene Expression and Psi Sigma Neural Networks
Georgios Sermpinis Jason Laws Andreas Karathanasopoulos Christian L. Dunis 《Expert systems with applications》2012,39(10):8865-8877
The motivation for this paper is to investigate the use of two promising classes of artificial intelligence models, the Psi Sigma Neural Network (PSI) and the Gene Expression algorithm (GEP), when applied to the task of forecasting and trading the EUR/USD exchange rate. This is done by benchmarking their results with a Multi-Layer Perceptron (MLP), a Recurrent Neural Network (RNN), a genetic programming algorithm (GP), an autoregressive moving average model (ARMA) plus a naïve strategy. We also examine if the introduction of a time-varying leverage strategy can improve the trading performance of our models. 相似文献
62.
The surface microstructure and polymorphic behavior of milk chocolate subjected to multiple thermal cycles between 20 and
32, 33, or 34°C were examined using atomic force microscopy (AFM) and powder X-ray diffraction (XRD). The surface of unbloomed
milk chocolate was smooth (surface roughness of 278 nm) and consisted of small, evenly distributed crystals. XRD results indicated
the presence of mostly form V crystals and little or no form VI crystals. Cycling between 20 and 32°C resulted in little bloom
formation and change in polymorphic behavior. Gradual bloom formation occurred as a result of cycling between 20 and 33°C,
and was accompanied by the nascence of form VI crystals. Surface roughness increased gradually from 417 nm after one cycle
to 476 and 521 nm after two and three cycles, respectively. Extensive bloom arose from cycling between 20 and 34°C. Surface
roughness increased from 373 nm after one cycle to 603 and 736 nm after two and three cycles, respectively. This heavily bloomed
chocolate consisted of jutting crystals and large raised, yet smooth areas that were haphazardly located within the chocolate
matrix. In summary, a new perspective on the development of surface bloom due to thermal cycling is provided. 相似文献
63.
分辨率增强技术(RET)设计流程中聚集了各式各样的点工具和方法。当前对深亚波长可制造性(DFM)设计的要求迫使设计与制造行业必须建立十分密切的合作关系。同时也促使EDA行业提供一种平台,以促进这些行业间的密切交流。合理利用这一平台将会对产能和品质产生直接的影响。 相似文献
64.
Performance of Alcohol and Safer Sex Change Rulers Compared With Readiness to Change Questionnaires.
LaBrie Joseph W.; Quinlan Thomas; Schiffman Jason E.; Earleywine Mitchell E. 《Canadian Metallurgical Quarterly》2005,19(1):112
As part of a larger intervention study, the authors hypothesized that change rulers created for alcohol and safer sex would be equivalent to longer questionnaires. Ninety-six male college students completed rulers and questionnaires for assessing behavior change readiness. Participants' scores on the rulers significantly correlated with their scores on the questionnaires (r = .77 for alcohol; r = .77 for safer sex). In both domains, the rulers outperformed the questionnaires in predicting behavioral intentions, suggesting that the rulers had at least comparable concurrent criterion validity. This finding is the first of its kind in the safe sex literature and suggests that quick assessments of readiness to change are possible. Because the rulers are a continuous measure, the results are consistent with the idea that the change process is continuous rather than a series of discrete stages. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
65.
Inhibition of return (IOR) refers to slower responding to a stimulus that is presented at the same, rather than a different location as a preceding, spatially nonpredictive, stimulus. Repetition priming refers to speeded responding to a stimulus that duplicates the visual characteristics of a stimulus that precedes it. IOR and repetition priming effects interact in nonspatial discrimination tasks but not in localization tasks; three experiments examined whether this is due to processing differences or due to response differences between tasks. Two stimuli, S1 and S2, occurred on each trial. In Experiment 1, S1 and S2 were both peripheral arrows; in Experiment 2, S1 was a central arrow and S2 was a peripheral nondirectional rectangle; in Experiment 3, S1 was a peripheral nondirectional rectangle and S2 was a peripheral arrow. S1 never required a response; S2 required a localization or a discrimination response. Despite evidence that form information was likely extracted from the arrow stimuli, the localization task revealed no repetition priming: IOR occurred regardless of shared visual identity of the S1 and S2 arrows. The discrimination task revealed IOR only when the visual identity changed from S1 to S2; otherwise, facilitation occurred. These results suggest that IOR is masked by repetition priming only when the response depends on the explicit processing of form information; repetition priming does not occur when such information is extracted automatically but is task (and response) irrelevant. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
66.
Jason P. Petti 《Engineering Fracture Mechanics》2005,72(1):91-120
This work proposes that the Weibull stress scale parameter, σu, increases with temperature to reflect the increasing microscale toughness of ferritic steels caused by local events that include plastic shielding of microcracks, microcrack blunting, and microcrack arrest. The Weibull modulus, m, then characterizes the temperature invariant, random distribution of microcrack sizes in the material. Direct calibration of σu values at temperatures over the DBT region requires extensive sets of fracture toughness values. A more practical approach developed here utilizes the so-called Master Curve standardized in ASTM Test Method E1921-02 to provide the needed temperature vs. toughness dependence for a material using a minimum number of fracture tests conducted at one temperature. The calibration procedure then selects σu values that force the Weibull stress model to predict the Master Curve temperature dependence of KJc values for the material. At temperatures in mid-to-upper transition, the process becomes more complex as fracture test specimens undergo gradual constraint loss and the idealized conditions of high-constraint, small-scale yielding assumed in E1921-02 gradually degenerate. The paper develops the σu calibration process to incorporate these effects in addition to consideration of threshold toughness effects and the testing of fracture specimens with varying crack-front lengths. Initial illustrations of the calibration process for simpler conditions, i.e. 1T crack-front lengths, use the temperature dependent flow properties and a range of toughness levels for an A533B pressure vessel steel. Then using the extensive fracture toughness data sets for an A508 pressure vessel steel generated recently by Faleskog et al. [Engng. Fract. Mech., in press], the paper concludes with calibrations of both m and σu over the DBT region and assessments of the Master Curve calibration approach developed here. 相似文献
67.
The discretized quadratic sub‐optimal tracker for nonlinear continuous two‐dimensional (2‐D) systems is newly proposed in this paper. The proposed method provides a novel methodology for indirect digital redesign for nonlinear continuous 2‐D systems with a continuous performance index. This includes the following features: (1) the 2‐D optimal‐linearization approach of the nonlinear 2‐D Roesser's model (RM), (2) the dynamic programming‐based discretized quadratic optimal tracker for linear continuous 2‐D systems, (3) the steady‐state discretized quadratic sub‐optimal tracker for linear continuous 2‐D systems, and (4) the discretized quadratic sub‐optimal tracker for nonlinear continuous 2‐D systems. Illustrative examples are presented to demonstrate the effectiveness of the proposed procedure. 相似文献
68.
Diefendorff James M.; Erickson Rebecca J.; Grandey Alicia A.; Dahling Jason J. 《Canadian Metallurgical Quarterly》2011,16(2):170
Emotional labor theory has conceptualized emotional display rules as shared norms governing the expression of emotions at work. Using a sample of registered nurses working in different units of a hospital system, we provided the first empirical evidence that display rules can be represented as shared, unit-level beliefs. Additionally, controlling for the influence of dispositional affectivity, individual-level display rule perceptions, and emotion regulation, we found that unit-level display rules are associated with individual-level job satisfaction. We also showed that unit-level display rules relate to burnout indirectly through individual-level display rule perceptions and emotion regulation strategies. Finally, unit-level display rules also interacted with individual-level dispositional affectivity to predict employee use of emotion regulation strategies. We discuss how future research on emotional labor and display rules, particularly in the health care setting, can build on these findings. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
69.
Sergey I. Shkuratov Jason Baird Vladimir G. Antipov Shujun Zhang Jay B. Chase 《Advanced materials (Deerfield Beach, Fla.)》2019,31(48)
A new type of energy storage devices utilizing multilayer Pb(Zr0.95Ti0.05)0.98Nb0.02O3 films is studied experimentally and numerically. To release the stored energy, the multilayer ferroelectric structures are subjected to adiabatic compression perpendicular to the polarization direction. Obtained results indicate that electrical interference between layers (10–120 layers) during stress wave transit through the structures has an effect on the generated current waveforms, but no impact on the released electric charge. The multilayer films undergo a pressure‐induced phase transition to antiferroelectric phase at 1.7 GPa adiabatic compression and become completely depolarized, releasing surface screening charge with density equal to their remnant polarization. An energy density of 3 J cm?3 is successfully achieved with giant power density on the order of 2 MW cm?3, which is four orders of magnitude higher than that of any other type of energy storage device. The outputs of multilayer structures can be precisely controlled by the parameters of the ferroelectric layer and the number of layers. Multilayer film modules with a volume of 0.7 cm3 are capable of producing 2.4 kA current, not achievable in electrochemical capacitors or batteries, which will greatly enhance the miniaturization and integration requirements for emerging high‐power applications. 相似文献
70.
随着可再生能源融合到传统电力系统中,电力系统的惯性显著降低,从而使系统对运行过程中受到的扰动非常敏感.本文提出了一种基于扰动的惯性估计方法,揭示了可再生能源对系统惯性的影响.然后,本文利用高斯过程回归方法对受扰动后的电力系统动态过程进行预测.大量实验表明,数据驱动的方法有效地估计了系统的惯性,并预测了受干扰后电网的动态... 相似文献