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81.
蔚小燕 《山西广播电视大学学报》2013,(4):60-62
色彩的巧妙运用是现代广告设计中不可缺少的因素,它在广告中具有重要的艺术功能,能更好地阐述广告要表达的内涵,文章从分析色彩与消费者的感官心理出发,阐述色彩在广告设计中的艺术功能,讨论在广告设计中色彩的配色规律及应用原则。 相似文献
82.
A compressed full-text self-index for a text T, of size u, is a data structure used to search for patterns P, of size m, in T, that requires reduced space, i.e. space that depends on the empirical entropy (H
k
or H
0) of T, and is, furthermore, able to reproduce any substring of T. In this paper we present a new compressed self-index able to locate the occurrences of P in O((m + occ)log u) time, where occ is the number of occurrences. The fundamental improvement over previous LZ78 based indexes is the reduction of the search
time dependency on m from O(m
2) to O(m). To achieve this result we point out the main obstacle to linear time algorithms based on LZ78 data compression and expose
and explore the nature of a recurrent structure in LZ-indexes, the suffix tree. We show that our method is very competitive in practice by comparing it against other state of the art compressed
indexes.
相似文献
Arlindo L. OliveiraEmail: |
83.
吴柳燕 《柳州职业技术学院学报》2008,8(1):133-136
本文分析了传统的布尔型文本匹配算法的弊端和缺陷,结合图书文本信息的快速、高效的检索匹配要求,提出了加权的布尔型文本匹配算法。该算法对传统的文本匹配算法中漏检、误检和模糊查询等方面的问题进行了加权处理和结果校正,既保证查询算法的高效与全面性,同时又有效地控制了匹配的准确度,为图书信息查询系统的建立提供一种更好的解决方法。 相似文献
84.
To observe the inner operating process of distance protection, a Matlab/Simulink based dynamic simulation system for microprocessor-based distance protection is designed in this pa- per. As a modularized design, the simulation system is composed of several modules such as fault transient calculation, startup, Fourier algorithm, phase selection, impedance computing and im- pedance comparison etc. Some typical simulation cases, which focus on the main factors affect- ing distance relay's operation, have been simulated with the system. Simulation results show that the system is able to demonstrate the dynamic behaviors of distance protection under different op- erating conditions. 相似文献
85.
86.
戚金凤 《北京工业职业技术学院学报》2019,18(3):16-23
根据汽车道路行驶的数学模型计算并联混合动力汽车驱动电机和发动机的各项参数,设计模糊控制策略控制驱动电机和发动机协调工作,使用Matllab/Simulink软件和Advisor汽车仿真软件联合建模仿真。在建模过程中,将上述计算结果输入Advisor汽车模型中,设置汽车的行驶工况、最高车速、加速时间和爬坡能力4个计算任务,并运行计算任务。仿真结果表明:汽车驱动电机和发动机的参数能匹配汽车整车参数、性能要求,模糊控制策略能在保证汽车整车性能要求的前提下进一步减少燃油消耗和尾气排放物,表明本驱动电机和发动机参数匹配设计方法、模糊控制策略均可行。 相似文献
87.
博士后制度具有培养和使用人才的双重属性,博士后经历既是人力资本投资亦是信号资本投资。基于2014年中国大学教师调查数据,运用倾向得分匹配法纠正样本自选择偏差后评估博士后经历的经济价值,研究发现:博士后经历具有显著的经济价值,拥有博士后经历的教师年收入比没有博士后经历的教师年收入高出11.40%。博士后经历的经济价值存在明显的异质性,"海归"博士后经历的经济效应是"本土"博士后经历经济效应的6.46倍。研究结论为未来青年博士职业发展路径选择、博士后管理制度改革与学术劳动力市场资源配置提供了实证依据。 相似文献
88.
Abstract Training abroad is an important avenue for promoting the specialized development of faculty and improving international accomplishments. On the basis of the data from the 2014 Faculty Survey in China, this paper applies the technique of propensity score matching to control for the self-selection bias in the sample, so as to quantitatively evaluate the economic benefits of training abroad for faculty. The study finds that training abroad presents significant economic returns, while the potential benefits of training abroad for faculty members who have not yet pursued training abroad are higher than the benefits for faculty members who have pursued training abroad; a nonlinear relationship exists between the period of time for which a faculty member pursues training abroad and the economic benefits thereof, with the order of the economic benefits of training abroad from least to most for different time periods being: 1?year, less than one half year, more than one half year to less than 1?year, and more than 1?year. The conclusions of the study provide an empirical basis for the selection of pathways for the professional development of faculty in the future, as well as the design and refinement of training abroad programs, et cetera. 相似文献
89.
Vivian C. Wong Jeffrey C. Valentine Kate Miller-Bains 《Journal of research on educational effectiveness》2017,10(1):207-236
This article summarizes results from 12 empirical evaluations of observational methods in education contexts. We look at the performance of three common covariate-types in observational studies where the outcome is a standardized reading or math test. They are: pretest measures, local geographic matching, and rich covariate sets with a strong theory of treatment selection. Overall, the review demonstrates that although the pretest often reduces bias in observational studies, it does not always eliminate it. Its performance depends on the pretest's correlation with treatment selection and the outcome, and whether preintervention trends are present. We also find that although local comparisons are prioritized for matching, its performance depends on whether comparable no-treatment cases are available. Otherwise, local comparisons may produce badly biased results. In cases where researchers have a strong theory of selection and rich covariate sets, observational methods perform well, but additional replication studies are needed. Finally, observational methods that rely on demographic covariates without a theory of selection rarely produce unbiased treatment effects. The article concludes by offering education researchers empirically based guidance on covariate selection in observational studies. 相似文献
90.
Electrical impedance tomography (EIT) is a new computer tomography technology, which reconstructs an impedance (resistivity, conductivity) distribution, or change of impedance, by making voltage and current measurements on the object's periphery. Image reconstruction in EIT is an ill-posed, non-linear inverse problem. A method for finding the place of impedance change in EIT is proposed in this paper, in which a multilevel BP neural network (MBPNN) is used to express the non-linear relation between the 相似文献