基于时域数据的两种低阶等效拟配方法研究

基于时域数据,对两种低阶等效拟配方法—频域等效拟配法和时域等效拟配法进行了研究.首先阐述了时域数据的两种来源,并对飞行试验数据中的关键参数给出了修正公式.以某型飞机为例,以两种输入形式进行了飞行动力学仿真,将得到的时域数据进行了低阶等效拟配.两种低阶等效拟配方法的结果和理论值吻合,且低阶等效系统仿真结果和原始时域数据重合度很高,表明方法合理有效.并根据操纵输入形式对辨识结果的影响对操纵输入的选取提出了要求.     

基于相空间重构及自适应支持向量机的短期风速预测

风速具有较强的随机性和间歇性,导致大规模风电接入电网会严重影响电力系统的安全稳定运行以及电能质量。较为准确的风速预测可以降低风能对电网的不利影响,为电网运行调度提供可靠的依据。在对风速进行混沌属性分析及相空间重构的基础上,采用自适应支持向量机进行短期风速预测,结果表明该方法的预测精度高于BP、RBF等预测模型。     

基于变量选择方法下的人民币汇率影响因素分析

在影响人民币汇率的众多因素中,选出GDP增长率、进出口差额增长率、货币和准货币供应量增长率、外汇储备增长率、中美相对消费价格指数、通货膨胀率和中美利差等7个影响人民币汇率的主要因素。选用了一种新的变量选择方法———自适应Lasso方法对人民币汇率影响因素进行有效的选择。同时使用真实数据作了实证研究,并与最小二乘法和逐步线性回归方法进行比较。结果表明：自适应Lasso方法在人民币汇率影响因素的选择方面,相对于逐步线性回归和最小二乘法有明显的优势。自适应Lasso方法不仅仅完成了模型的参数估计,同时也完成了对影响人民币汇率因素的筛选。     

编组站车流接续优化模型及算法

在解编顺序给定的条件下,建立车流接续优化模型。在模型构建中,列车属性方面同时考虑了换重、换长和满轴三个约束,通过算例证明,该设定不但更加符合实际,而且使得车流接续优化具有了一定的灵活性。在算例分析部分,分别利用一般数学软件Lingo11.0以及VC++编写的自适应免疫克隆算法对模型进行求解,证明了模型和算法的有效性,为编组站阶段计划车流接续优化智能化提供了较好的解决途径。     

Deep habits and the cyclical behaviour of equilibrium unemployment and vacancies

We extend the standard textbook search and matching model by introducing deep habits in consumption. This assumption generates amplification in the response of labour market variables to technology shocks by producing endogenous countercyclical mark-ups. The cyclical fluctuations of vacancies and unemployment in our model can replicate those observed in the US data, with labour market tightness being 20 times more volatile than consumption. Vacancies display a hump-shaped response to technology shocks and the numerical simulations generate an artificial Beveridge curve that is in line with the data. Our model preserves the assumption of fully flexible wages for new hires and the calibration is consistent with the estimated elasticity of unemployment to unemployment benefits. Finally, we show that in contrast to models with exogenous mark-up shocks, the deep habits model does not require an implausible variation in the elasticity of demand to match the volatility of labour market variables, and the cyclical properties of the mark-up are in line with empirical evidence.     

The Impact of Market Orientation on the Internationalization of Retailing Firms: Tesco in Eastern Europe

This paper investigates a Western retailer's market orientation levels in two emerging markets. We examine whether the market orientation-company performance link holds true for retailers in emerging economies, despite environmental differences. By using concepts from key studies we have assimilated a fully representative model - applied through interviews with top management from Tesco and its subsidiaries and affiliates in Hungary and Slovenia. Using this example, we find that the market orientation-business performance link is valid for Western retailers in emerging economies. Here, the retailer applied market orientation predominately through; the use of matching with suppliers of own brand goods; top management emphasis on market orientation and risk taking. Intelligence generation and dissemination was exercised via global processes such as brand review.     

Fiscal stimulus and labor market dynamics in Japan

The paper studies the effects of fiscal expansion on the Japanese labor market. First, using a structural VAR model, we find that the unemployment rate falls and employment rises following an increase in government spending. We also find that fiscal expansion affects flows in and out of unemployment. While an increase in government spending increases the job-finding rate, it reduces the separation rate. We then incorporate search and matching frictions into a standard dynamic general equilibrium model, and study whether the model can explain what we observed in data. While the model fails to predict the exact size of the impact of government spending shocks on the Japanese labor market variables, it can consistently capture the empirical pattern of responses of labor market variables to shocks.     

How Market-Guanxi Ambidexterity Affects Adaptive Capability in China＇s Transition Economy

Whether market- and guanxi-based strategies are complementary or substitutable in shaping adaptive capability is a critical yet controversial issue. This paper tackles this problem by adopting the ambidexterity perspective. Specifically, using a sample of 185 Chinese private firms, this study examines the independent and interactive effects of market orientation （MO） and guanxi orientation （GO, i.e., emphasizing on building business and political ties） on adaptive capability of firms in transition economies. Our results suggest that both direct impacts and complementary impacts of MO and GO strongly exist in shaping firms＇ adaptive capability, indicating the importance of ＂strategic ambidexterity.＂ These findings have several theoretical implications for studies on ambidexterity and adaptive capability, and practical implications for finn strategies in transition economies.     

Fiscal stimuli in the form of job creation subsidies

This paper examines the effects of fiscal stimuli in the form of job creation subsidies in a DSGE model with search friction and endogenous job separation. We consider two types of job creation subsidies: a subsidy for the cost of posting vacancies and a hiring subsidy. This paper finds that the effects of job creation subsides on unemployment differ between models with and without endogenous job separation. While a positive job creation subsidy shock lowers unemployment in a model without endogenous job separation, it increases unemployment in a model with endogenous job separation. We also find that while qualitatively the effects of a vacancy cost subsidy on the economy are similar to those of a hiring subsidy, quantitatively they are different.     

Comparison of Effects from Different Institutions: Public Credit Guarantee in Korea*

We aim to compare the activities of the two main credit guarantee institutions in Korea. There has been mounting criticism that although these institutions were mandated to play different roles in financing small and medium‐sized enterprises (SME), their operations are, in fact, similar, and many SME receive overlapping support from both institutions. Using the propensity score matching method (allowing for multiple, mutually exclusive support scenarios) to compare the effects of PCG on different institutions, the present study provides suggestions to help the government make decisions regarding the consolidation of PCG funds. The results suggest that the institutions function differently and target different SME. However, overlapping support enables firms to expand their sales only, indicating the existence of inefficiency in the case of overlapping support to firms.