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61.
Weiwei Yang Jiejunyi Liang Jue Yang Paul D. Walker Nong Zhang 《Journal of The Franklin Institute》2021,358(2):1214-1239
An hybrid uninterrupted multi-speed transmission (HUMST), based on the integration of a planetary gear set and a 3-speed automatic manual transmission (3-AMT), is developed to satisfy the specific performance indexes of mining trucks. The power-split device can alleviate and eliminate the inherent torque interruption of the 3-AMT during gear shift by implementing the designed cooperative shift control strategy which is optimized by quadratic performance index. In order to achieve fast torque coordination while guaranteeing the driving comfort performance, the torque profiles of the power split device and the traction motor are optimized by Linear-quadratic regulator (LQR) algorithm. Dynamic programming (DP) is implemented as a benchmark to demonstrate the maximum fuel efficiency of the proposed HUMST. Because of the high computational cost of optimal control strategies such as DP, an improved real-time control strategy (IRTCS) using modified Gaussian distribution function is proposed to significantly reduce the computing load. As efficiency-oriented energy control strategy would result in frequent gear shifts, to achieve a desirable tradeoff between the overall efficiency and the shift stability, multi-objective genetic algorithm (MGA) is integrated to optimize the overall performance. The detail mathematical and dynamic model shows that the proposed shifting strategy with LQR can effectively suppress shift jerk, and the proposed IRTCS with MGA can reduce shift frequency by 70.78% to improve the drivability, only sacrificing 4.86% of overall efficiency compared to that of DP. 相似文献
62.
Andrea C. Walker Rachelle Gewecke Illene N. Cupit Jeffrey T. Fox 《Journal of College Counseling》2014,17(2):131-149
This phenomenological study, based on ecological systems theory, examined the college student bereavement experience in a Christian university. Undergraduate students (N = 127) from a small Christian university provided answers to open‐ended questions about their experiences regarding college following a death loss. Results indicate that students are generally successful in adapting to bereavement and prefer an environment open to discussing death and asking difficult religious questions. Implications for counselors are provided. 相似文献
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This study reports on a very successful collaboration between teacher education courses in Manchester and Amsterdam and the Van Gogh Museum in Amsterdam. The central aim of the initiative was to promote and sustain partnerships between Higher Education (HE) institutions, public galleries and schools with a view to developing, delivering and sharing good practice in art and design within a European context. 相似文献
65.
In this paper we review arguments that have been well rehearsed in the economic literature in the past twenty years and which are relevant to the present debate over student loans and the funding of the higher education sector.
The body of the paper assesses four finding proposals: (1) The Government's mortgage-type loan scheme, (2) The Barr, National Insurance repayment scheme, (3) The Graduate Tax and (4) A Loan scheme based on the individual higher education institution.
Each proposal is assessed in terms of its efficiency impact in six dimensions, (i) set up costs and flexibility, (ii) administrative costs (iii) incentives (iv) information (v) the balance of public and private involvement, and (vi) equity.
We conclude that, overall, we would not recommend any of the alternatives as unambiguously superior on all counts. Insofar as a radical approach is to be implemented we argue that a scheme based on the individual higher education institution, with repayment via the National Insurance system, is probably the best option. 相似文献
The body of the paper assesses four finding proposals: (1) The Government's mortgage-type loan scheme, (2) The Barr, National Insurance repayment scheme, (3) The Graduate Tax and (4) A Loan scheme based on the individual higher education institution.
Each proposal is assessed in terms of its efficiency impact in six dimensions, (i) set up costs and flexibility, (ii) administrative costs (iii) incentives (iv) information (v) the balance of public and private involvement, and (vi) equity.
We conclude that, overall, we would not recommend any of the alternatives as unambiguously superior on all counts. Insofar as a radical approach is to be implemented we argue that a scheme based on the individual higher education institution, with repayment via the National Insurance system, is probably the best option. 相似文献
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Many educational and psychological tests are inherently multidimensional, meaning these tests measure two or more dimensions or constructs. The purpose of this module is to illustrate how test practitioners and researchers can apply multidimensional item response theory (MIRT) to understand better what their tests are measuring, how accurately the different composites of ability are being assessed, and how this information can be cycled back into the test development process. Procedures for conducting MIRT analyses–from obtaining evidence that the test is multidimensional, to modeling the test as multidimensional, to illustrating the properties of multidimensional items graphically-are described from both a theoretical and a substantive basis. This module also illustrates these procedures using data from a ninth-grade mathematics achievement test. It concludes with a discussion of future directions in MIRT research. 相似文献
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Differences in racial socialization practices and their effects were examined in a sample of 241 African American 1st graders (average age 6.59 years) living in an urban area. Child outcomes included cognitive development, receptive language skills, and child problem behavior. The cultural environment of the home was associated with higher cognitive scores for boys living in high negative social climate and low social capital neighborhoods and for girls living in high social capital neighborhoods. The positive association of promotion of mistrust and child behavior problems was magnified in neighborhoods that had low levels of social capital. A high negative social climate in the neighborhood attenuated the positive association between preparation for bias/promotion of mistrust and externalizing problems. 相似文献