转型经济财富分布基于主体的经济仿真

本文利用基于主体的计算机仿真方法,模拟了传统经济与现代化产业并存的二元经济体实现工业化的财富分布动态过程,检验了不同的经济政策对经济增长和财富分配的影响。针对我国的具体国情,模拟出基尼系数高居不下的情景,并提出从初次分配的源头上遏制收入分配差距过大的根本措施。     

田间非饱和土壤水分运动的数值模拟—Ⅱ数学模型及数值模拟

经过对条件的概化，建立了带有作物根系吸水项的垂向一维土壤水分运动的数学模型，并推导了该模型的数值离散方程，编制了用于该模型数值模拟的计算程序。通改数值模拟对模型的验征，计算值与实测值拟合较好，这表明，该模型是可靠的，数值方法是可行的，可以用来模拟作物生长条件下田间土壤水分的运动。     

典型物流仿真软件特点简析与教改探讨

以两款典型物流仿真软件RaLC和Arena为例,介绍其基本功能和各自特点,讨论其变量差异与物流仿真软件的类别划分,并针对物流仿真教学提出"三把握三衔接"的教改建议。     

地方政府债务风险非线性仿真预警系统的构建——基于粗糙集-BP神经网络方法集成的研究

在设计地方政府债务风险预警指标体系框架的基础上,吸收了粗糙集和BP神经网络等人工智能方法在数据处理上的优点,构建出基于粗糙集-BP神经网络集成的地方政府债务风险非线性仿真预警系统。选取我国2007～2009年东、中、西部地区9个县的27个样本数据,运用该非线性仿真预警系统进行了地方政府债务风险预警实证分析。研究结果表明,大部分样本地区的债务风险都处于"中警"及以上状态,地方政府债务风险普遍较高,同时,样本地区债务风险综合评价值是不断提高的,说明近年来我国地方政府债务风险呈现出不断上升的趋势。与单纯的BP神经网络仿真预警系统相比,该仿真预警系统不仅降低了BP神经网络的复杂性,节省了训练时间,而且具有更好的预警准确性和推广应用价值。     

经济管理仿真实验系统开发分析——基于模块化与柔性化设计

国内高校经济管理实验室普遍存在资源配置缺乏系统规划、资源重置度高、资源共享度差、仪器设备及软件利用率低、科研潜力无从挖掘、实验活动偏离实际等问题。针对这些问题并结合国内外高校经济管理实验室运作的成功典范建立的仿真实验系统平台,可以优化和改造传统的经济管理实验室运作模式,即通过模块化、柔性化设计来增进经济管理类实验室系统的功能效用。     

自适应模糊控制在VAV末端装置中的应用

通过增加在线模糊调整量化增益和比例增益,在简单模糊控制理论的基础上架构成自适应模糊控制理论,并把其运用于 VAV 空调末端装置的控制.通过 MATLAB 分别建立简单模糊控制系统和自适应模糊控制系统的仿真模型并加以仿真.对比二者的仿真结果可见,针对 VAV 空调末端装置控制,自适应模糊算法比简单模糊算法效果更佳.     

Welfare impacts of new demand-enhancing agricultural products: The case of Honeycrisp apples

Agricultural research and development programs on new demand-enhancing products have become increasingly important over the past decade. Large numbers of new agricultural products have been developed and commercialized in the United States to meet consumers’ increasingly diverse expectations for food quality. However, little is known about their economic benefits. Focusing on the apple market, we investigate the welfare impacts of the introduction of Honeycrisp apples in a market equilibrium framework. We use market data on apple sales from 61 cities across the United States between 2009 and 2015. We find the introduction of Honeycrisp increased consumer welfare, which is mainly explained by the increased number of total apple varieties. We also find that the introduction of Honeycrisp apples has increased overall market size and total apple sales. To extrapolate our results to the entire U.S. apple market, we perform a back-of-the-envelope analysis and find that the introduction of Honeycrisp apples has increased total consumer welfare by about 859 million dollars during the study period. This corresponds to approximately 19% of the annual average domestic expenditures on public food and agricultural R&D.     

飞机客舱地毯清洗机的设计分析

对飞机客舱地毯清洗进行研究,确定地毯清洗过程,设计出一款结构体积小、操作方便、成本低的飞机客舱地毯自动清洗机,来提高地毯清洗的效率。地毯清洗机是一个多功能集成的机构,可实现对地毯进行除尘、清洗、漂洗以及压干脱水处理,根据各部分的清洗要求,分别对结构进行工作原理分析,并进行相应的结构设计;最后对地毯清洗机的关键部位进行静力学、模态、瞬态动力学仿真分析,验证结构的强度、刚度要求。     

FFORMPP: Feature-based forecast model performance prediction

This paper introduces a novel meta-learning algorithm for time series forecast model performance prediction. We model the forecast error as a function of time series features calculated from historical time series with an efficient Bayesian multivariate surface regression approach. The minimum predicted forecast error is then used to identify an individual model or a combination of models to produce the final forecasts. It is well known that the performance of most meta-learning models depends on the representativeness of the reference dataset used for training. In such circumstances, we augment the reference dataset with a feature-based time series simulation approach, namely GRATIS, to generate a rich and representative time series collection. The proposed framework is tested using the M4 competition data and is compared against commonly used forecasting approaches. Our approach provides comparable performance to other model selection and combination approaches but at a lower computational cost and a higher degree of interpretability, which is important for supporting decisions. We also provide useful insights regarding which forecasting models are expected to work better for particular types of time series, the intrinsic mechanisms of the meta-learners, and how the forecasting performance is affected by various factors.     

基于Anylogic的机场安检流程研究

以机场安检通道为研究对象,通过调查安检通道的具体参数及旅客在安检环节中的行为参数,利用Anylogic仿真软件建立机场安检通道流程模型。借助Anylogic软件,对安检流程中的旅客通行情况进行仿真研究。根据仿真结果中的行人排队队长、行人密度分布等数据分析安检环节中存在的瓶颈点,提出相应的改进意见并修改模型。最终结果表明,改进意见可以较好地缓解安检流程中的瓶颈点问题,使旅客通行效率得到一定程度的提高。