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1.
《Socio》2021
Traffic congestion is an unpreventable problem to avoid in a transportation network and it has negative effects on traffic accident, time wasting, traffic delay and safety problem. Besides, in transportation networks, drivers do not want to deal with traffic jam while traversing between specified origin-destination pair. Therefore, traffic assignment (TA) is imperative to improve traffic management, transportation safety, time, and cost savings. System Optimum Traffic Assignment Problem (SOTAP) is a kind of TA model which aims to minimize the total system travel time on the network, and satisfies the flow conservation constraints. To model the SOTAP more realistically, the imprecise parameters can be taken as fuzzy. Therefore, in this paper, we focus on converting the conventional SOTAP to a fuzzy quadratic programming problem (QPP) which is named System Optimum Fuzzy Traffic Assignment Problem (SOFTAP). Here, link travel time is expressed with BPR function as generally used in the literature by converting to fuzzy except link-dependent parameters. Thus, the nonlinear objective function of SOFTAP is expressed in terms of fuzzy link flows and fuzzy link travel times. A solution approach from the literature is modified to the reconstructed SOFTAP. 相似文献
2.
知识互动程度评价对改善高校跨学科创新团队知识互动具有重要意义。在界定高校跨学科创新团队知识互动及知识互动程度内涵的基础上,创新性地从知识互动深度、互动广度、互动时间3个维度建立知识互动程度评价指标体系。进一步地,采用三角模糊权重、熵权和模糊积分相结合的方法,构建知识互动程度评价模型。最后,选取一所高校跨学科创新团队进行实例分析,验证评价模型的可操作性,可为高校跨学科创新团队知识互动程度评价提供一个新视角。 相似文献
3.
This research explores the physical infrastructure and flight consolidation efficiency drivers of Eurasian airports regarding their infrastructure and movement productivity levels. A novel Fuzzy Double-Frontier Network DEA (FDFNDEA) model is proposed to investigate the relationship between desirable (freight and passenger turnovers) and undesirable (pollutant emission levels due to aircraft movements) outputs against the respective infrastructure usage, fuel consumed, and movements performed at each of the 23 Eurasian airports from 2000 to 2018. This balance between desirable and undesirable outputs emerges spatially and temporally due to the evolution of the airport system's productive resources at each one of the Eurasian countries over the period observed. Shannon's entropy is used as the cornerstone to quantify the input and output vagueness of this evolution in Triangular Fuzzy Numbers (TFN), thus allowing the accurate building of alternative optimistic and pessimistic double-frontier efficiency. Differently from previous research, Shannon's entropy is the key for measuring input and output vagueness levels in light of the maximal entropy principle. This principle states that the distribution that best represents the current state of knowledge is the one with largest entropy. Maximal entropy yields bias-free decision-making in the sense that the input/output distributional profiles for Eurasian airports contain the maximal possible heterogeneity, working as a robust or best/worst-case scenario against eventual unconsidered assumptions. Hence, optimistic and pessimistic Malmquist Productivity Indexes (MPI) for overall and each stage productivity results are subsequently regressed against contextual variables related to airport characteristics and regional socio-demographic and economic indicators of each Eurasian country using bootstrapped Cauchy regressions. The findings revealed the spatial heterogeneity of productivity factors and airport performance across Eurasia. Results also demonstrated the negative impact of income inequality and the positive impact of private participation on technological progression in the Eurasian airport industry. 相似文献
4.
5.
张彬 《山西经济管理干部学院学报》2005,13(2):89-90
素质教育倡导数学教学应重视学生的主观能动性,力求使学生亲身经历数学问题的发现过程,体验研究成果的喜悦。文章就发现法教学从理论到实践阐述了这种教学方式的五种途径。 相似文献
6.
多媒体技术在数学教学中的应用 总被引:1,自引:0,他引:1
宋建梅 《山西经济管理干部学院学报》2005,13(2):87-88
要深化教学改革必须充分发挥信息技术的优势,采用多媒体技术进行数学教学势在必行。文章从激发学习兴趣、提高学习效率、优化教学过程等方面阐述了运用多媒体技术进行数学教学的必然性、可行性、优越性。 相似文献
7.
Tina Hviid Rydberg 《Finance and Stochastics》1997,1(3):251-257
Simple sufficient conditions for the existence of a unique equivalent martingale measure are provided. Furthermore, these
conditions give us a handle on situations where an equivalent martingale measure cannot exist. The existence of a unique equivalent
martingale measure is of relevance to problems in mathematical finance. Two examples of models for which the question of existence
was unresolved are studied. By means of our results existence of a unique equivalent measure up to an explosion time is proved. 相似文献
8.
We provide specific qualifications in order that Kuhn–Tucker type Euler equations and transversality conditions at infinity
hold in stochastic equilibrium models with heterogeneous agents and where assets are traded in sequential markets. It is not
assumed that uncertainty is modeled as an event-tree structure or that preferences are necessarily bounded. We also describe
an important class of preferences based on bounded relative risk aversion which yields relevant simplifications. Our results
are used to establish conditions that rule out asset pricing bubbles. Specific examples of economies with bubbles are also
discussed.
Received: 28 January 2002 / Accepted: 19 July 2002
We are grateful to the editor and an anonymous referee for their valuable comments. This research was partially supported
by MURST (Italy), National Group on “Nonlinear Dynamics and Stochastic Models in Economics and Finance”. 相似文献
9.
Chi-Yo Huang Author Vitae Author Vitae 《Technological Forecasting and Social Change》2008,75(1):12-31
Product life cycle (PLC) prediction plays a crucial role in strategic planning and policy definition for high-technology products. Forecast methodologies which can predict PLCs accurately can help to achieve successful strategic decision-making, forecasting, and foresight activities in high-technology firms, research institutes, governments, and universities. Over the past few decades, even though analytic framework strategies have been proposed for production, marketing, R&D (research and development), and finance, aiming at each stage of PLCs, forecast methodologies with which to predict PLCs are few. The purpose of this research is to develop a novel forecast methodology to allow for predictions of product life time (PLT) and the annual shipment of products during the entire PLC of multiple generation products. A novel two-stage fuzzy piecewise regression analysis method is proposed in this paper. In the first stage, the product life-time of the specific generation to be analyzed will be predicted by the fuzzy piecewise regression line that is derived based upon the product life-time of earlier generations. In the second stage of the forecast methodology, the annual shipment of products of the specified generation will be predicted by deriving annual fuzzy regression lines for each generation, based upon the historical data on the earlier generations' products. An empirical study predicting the life-time and the annual shipment of the 16 Mb (Mega bit) DRAM (Dynamic Random Access Memory) PLC is illustrated to validate the analytical process. The results demonstrate that two-stage fuzzy piecewise regression analysis can predict multiple generation PLT and PLC precisely, thereby serving as a foundation for future strategic planning, policy definitions and foresights. 相似文献
10.