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排序方式: 共有601条查询结果,搜索用时 31 毫秒
31.
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
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33.
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
34.
“藏汉双语”教师的专业发展对于提高广大藏区基础教育质量意义重大。研究从影响“藏汉双语”教师专业发展的问题入手,对“藏汉双语”教师的教学认知能力、人际交往倾向、职业发展动机、自我评价等方面进行系统分析,探索“藏汉双语”教师专业发展的环境调控和优化的策略。 相似文献
35.
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
36.
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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38.
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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40.
Shaul SHALVI Matthijs BAAS Michel J. J. HANDGRAAF Carsten K.W. DE DREU 《Learned Publishing》2010,23(2):117-123
At a top psychology journal, Psychological Science (PS), submissions peak during the summer months. We tested whether this seasonal submission bias decreases the likelihood of a paper being accepted in that period. Month of submission data was obtained for all 575 publications in PS for the period 2003–2006. Whereas submissions to PS were higher in the summer, there was no evidence that most accepted publications were originally submitted in the summer. Thus, contributors submit to PS when the likelihood of acceptance is the lowest – creating their own entrance barrier. A similar seasonal pattern was not identified for Personality and Social Psychology Bulletin, another top psychology journal. Using the Web of Knowledge database, we further assessed whether overcoming the seasonal entrance barrier influences the number of citations a paper receives in subsequent years. We discuss the possibility that the different rejections policies in the two journals, employing desk rejections or not, may explain this discrepancy, and explore a range of alternative hypotheses. 相似文献