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1.
山秋月  吴永强 《科技和产业》2023,23(14):223-227
针对全货运航空公司,研究其货运航线网络的构建问题。基于单分配严格枢纽航线网络,对传统模型进行改进。以各航线上货物的委托运输成本和自有机队的运输成本,取代传统的单位运输成本和折扣因子,考虑枢纽点的中转成本和载运率对路径选择的影响。结合航空货运夜航的特征考虑各机队夜间可用时间的限制,以总成本最小为目标,构建数学模型,采用LINGO优化软件求解,验证模型的有效性,为全货运航空公司构建货运航线网络提供参考。  相似文献   
2.
In this article, Copula GARCH models have been employed to study the inter-temporal process of currency market co-movements between ASEAN+6 countries (referred to in this study as East Asian Economic Community) and ASEAN+6 currency market index. Empirical results show that the sample countries of the region exhibit varying levels of currency co-movements with the Asian benchmark. Markov regime switching results show that many of the countries which had high dependences with the regional currency index as was found in copula estimations had also overlapping currency market cycles. Using Principal Component Analysis, we find that three statistical factors explain exchange rate co-movements which came out to be trade linkages, economic risk, and currency market openness in our dynamic panel data estimation.  相似文献   
3.
Cycle time forecasting (CTF) is one of the most crucial issues for production planning to keep high delivery reliability in semiconductor wafer fabrication systems (SWFS). This paper proposes a novel data-intensive cycle time (CT) prediction system with parallel computing to rapidly forecast the CT of wafer lots with large datasets. First, a density peak based radial basis function network (DP-RBFN) is designed to forecast the CT with the diverse and agglomerative CT data. Second, the network learning method based on a clustering technique is proposed to determine the density peak. Third, a parallel computing approach for network training is proposed in order to speed up the training process with large scaled CT data. Finally, an experiment with respect to SWFS is presented, which demonstrates that the proposed CTF system can not only speed up the training process of the model but also outperform the radial basis function network, the back-propagation-network and multivariate regression methodology based CTF methods in terms of the mean absolute deviation and standard deviation.  相似文献   
4.
党的十九大报告指出:“要坚决打好防范化解重大风险攻坚战,其关键又是防范金融风险,包括防范中国系统性金融风险的发生和抵御国际性金融危机传导所带来的外部冲击。”2007年由美国次贷危机演变成的全球性金融危机,至今还在持续影响着部分国家的经济和金融发展。2015年底开始的美国第六轮加息周期和2018年3月中美贸易战的爆发,使得中国的经济发展面临更大的机遇和挑战。本文以次贷危机为背景,基于MIMIC模型对2005—2016年的美国金融危机压力进行了测度,找到压力的来源为外汇储备增长率、出口增长率和实际有效汇率高估三个方面,进而分析其产生的根本原因,最后从三方面提出中国防范化解重大风险的对策和启示。  相似文献   
5.
This article investigates the patterns of vertical specialization in trade among China, Japan and Korea, and the effects of real exchange rate fluctuations under a multistage production process. By extending the models of Yi (2003, 2010), we derive two distinct features of vertical specialization and test them using Time-Varying Parameter (TVP) VAR. We find that a positive shock to China’s final good consumption increases the intermediate goods trade between Korea and China, with expanding magnitude over time. In addition, the positive effect of a real exchange rate depreciation on intermediate goods trade is strengthened through the competitiveness-enhancing channel, with this effect being more pronouncing in Korea-China trade than in Korea-Japan trade.  相似文献   
6.
在单因素试验的基础上,确定以滚筒蒸汽压力、滚筒转速和料膜厚度为3个主要因素,以成膜率、色泽和水分含量为响应值,采用响应面法设计优化滚筒干燥工艺参数。结果表明:米粉滚筒干燥工艺最优参数为:滚筒蒸汽压力0.45 MPa、滚筒转速3.5 r·min-1、料膜厚度0.2 mm。验证结果与理论值接近,说明所得工艺参数准确可靠,可用于实际生产操作。  相似文献   
7.
We explore the effects of the COVID-19 crisis and the associated restrictions to economic activity on paid and unpaid work for men and women in the United Kingdom. Using data from the COVID-19 supplement of Understanding Society, we find evidence that labour market outcomes of men and women were roughly equally affected at the extensive margin, as measured by the incidence of job loss or furloughing. But, if anything, women suffered smaller losses at the intensive margin, experiencing slightly smaller changes in hours and earnings. Within the household, women provided on average a larger share of increased childcare needs, but in an important share of households fathers became the primary childcare providers. These distributional consequences of the pandemic may be important to understand its inequality legacy over the longer term.  相似文献   
8.
We examine the impact of the introduction of VIX exchange‐traded products (ETPs) on the information content and pricing efficiency of VIX futures. We document that trades in VIX futures have become less informative and that pricing errors exhibit more persistence after the introduction of VIX ETPs. In addition, we observe that the price process of the VIX futures has become noisier over time. These findings suggest that the introduction of the VIX ETPs had a prominent effect on the properties and dynamics of the VIX futures.  相似文献   
9.
Domestic credit expansion in CEE economies, fuelled in part by foreign capital inflows, helped increase household welfare before the 2008 financial crisis caused a contraction across the region. How strong are the linkages between the current account, domestic credit and consumer spending? This study compiles a quarterly dataset of domestic credit as a share of GDP for 11 CEE European Union members and isolates structural breaks in the series’ growth rates that often align with the 2008 crisis. Vector autoregressive methods, particularly impulse response functions, show that increased current-account deficits lead to increased consumption in six of the 11 countries and increased credit growth in three, and that shocks to credit growth increase consumption in six countries. Capital inflows significantly increase consumption through domestic credit in Slovenia, while the Baltics show a large share of significant effects.  相似文献   
10.
Trends in master of business administration (MBA) education are favoring coursework offerings in time-compressed environments but without careful examination of learning implications. The academic literature is weak in this area, so the authors conducted a study of 558 MBA students using a behaviorally based pedagogy in management. In contrast to previous research, the authors developed arguments supporting time compression assuming certain boundary conditions. They found that students showed better behavioral learning outcomes in a shortened, 4.5-week semester versus a full 14-week semester. The authors conclude with implications for theory and practice.  相似文献   
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