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981.
邱文昌 《上海海事大学学报》1994,(4)
应用系统工程的方法,建立了由3个大类、6项分条目、24项条目指标组成的集装箱船积载计划评价指标体系;经过对评价指标的定量化、归一化处理以及特尔菲法的专家咨询,建立了指标的评价数学模型。在此基础上,设计了集装箱船积载计划计算机评价系统。对该评价系统的研究,将为最终实现应用计算机编制最佳集装箱船积载计划的全过程创造条件。 相似文献
982.
中水是解决城市水资源紧缺的重要手段之一,如何使中水资源调度和管线建设达到最优化是当前中水资源利用所面临的亟待解决问题之一。本文基于系统论的基本原理,根据中水利用的过程状况和现实条件,通过对中水利用系统进行模拟分析,从成本、距离和获取量的宏观角度建立起中水利用优化的五套线性规划模型。在建立模型过程中,充分考虑到中水资源实际利用时的特点,针对不同情况分别采用了专家打分法,用水量比拟权重法,用水地面积比拟权重法等。在模型的编程过程中,实现模型与地理信息系统相结合,从而达到自动提取空间物体的面积、长度等属性数据,便于模型在运行过程中修改数据。通过五套模型的组合使用,最大程度上优化中水资源的利用,为中水资源的优化分配提供技术支持,为输送管线的改造和铺设提供辅助决策支持,从而全面促进中水资源的科学利用,保护有限的淡水资源。 相似文献
983.
Joaquín M. Azagra-Caro Fragiskos Archontakis Antonio Gutiérrez-Gracia Ignacio Fernández-de-Lucio 《Research Policy》2006,35(1):37-55
The growing importance of regions in the analysis of innovation and the pressure on European universities to interact with their environment justify this article. It argues that faculty support for the objectives of university-industry relations (UIR) does not vary across disciplines and does not respond to university encouragement in a region with low absorptive capacity. These results are in contrast with those obtained in studies of technology leading countries like the USA. Furthermore, incentives for UIR may generate unpredicted dynamics while instruments to cooperate are not significant. Finally, support for the objectives of UIR should not be confused with the degree of R&D cooperation. The former is sensitive to university age while the latter is sensitive to gender, discipline, commitment to R&D and university encouragement. Empirical evidence is obtained from a sample of faculty from the Valencian Community (Spain) and analysed through a set of models for discrete choice. 相似文献
984.
985.
技术创新过程模式的发展演变及战略集成 总被引:19,自引:2,他引:19
本文回顾了传统技术创新过程模式的演变、特征、缺陷和环境,讨论了第五代技术创新模式的战略集成,最后简要介绍了技术创新过程模式的选择以及我国程控交换机制造业技术创新过程模式的变化趋势。 相似文献
986.
本文对网络环境下的信息进行了重定义,对网络信息服务涉及的各因素进行了设定及量化分析,进而提出了网络信息服务量化模型,为提高网络信息服务质量提供了科学依据。 相似文献
987.
This paper reports on a study in which students used agent-based computer models to learn about complex systems ideas of relevance to understanding climate change. The experimental condition used a Productive Failure (PF) learning design in which ninth grade students initially worked with agent-based computer models to solve challenge problems followed by teacher instruction about targeted climate and complexity ideas. In contrast, the comparison condition employed a Direct Instruction (DI) learning design in which the teacher instruction was provided initially, followed by the students working on the same computer models and challenge problems as the experimental group. The students in the PF group scored significantly higher on the post-test on measures of climate and complex systems explanatory knowledge and near and far knowledge transfer. Theoretical and practical implications of these findings are considered. 相似文献
988.
《Journal of Informetrics》2020,14(1):101003
Extensive literature demonstrates how the copying of references (links) can lead to the emergence of various structural properties (e.g., power-law degree distribution and bipartite cores) in bibliographic and other similar directed networks. However, it is also well known that the copying process is incapable of mimicking the number of directed triangles in such networks; neither does it have the power to explain the obsolescence of older papers. In this paper, we propose RefOrCite, a new model that allows for copying of both the references from (i.e., out-neighbors of) as well as the citations to (i.e., in-neighbors of) an existing node. In contrast, the standard copying model (CP) only copies references. While retaining its spirit, RefOrCite differs from the Forest Fire (FF) model in ways that makes RefOrCite amenable to mean-field analysis for degree distribution, triangle count, and densification. Empirically, RefOrCite gives the best overall agreement with observed degree distribution, triangle count, diameter, h-index, and the growth of citations to newer papers. 相似文献
989.
Implicit theories of intelligence play an important role in students’ academic motivation and achievement. This longitudinal study examined how the trajectories of implicit theories of intelligence from Grade 8 to Grade 10 were related to Grade 12 SAT achievement via Grade 11 achievement goals. We employed parallel process models to examine changing patterns of Korean students’ (N = 6491) entity and incremental theories over three years. Results showed that both entity and incremental theories increased over time. The intercept and the slope of entity theory were negatively related with the intercept and the slope of incremental theory, respectively. In line with Dweck’s theoretical framework, increases in incremental theory were found to predict SAT achievement via mastery-approach goals, whereas increases in entity theory predicted SAT achievement via performance-approach goals. The results indicate that different types of achievement goals play unique roles in mediating the relation between changes in implicit theories and SAT achievement. 相似文献
990.
In an era where market consolidation is becoming the norm for proprietary library content and technology services, library consortia are left wondering what they can do to mitigate or counteract the resulting negative consequences. This article explores challenges with respect to market consolidation, and the approaches taken in recent collaborative community-owned projects, including CC-PLUS and FOLIO, in which the authors are involved. These projects may impede market consolidation effects and serve as examples, providing new models for consortial collaboration and those interested in cultivating agency in the provision of core library technology services. 相似文献