山地地区地表一致性剩余静校正技术应用技巧

山地地区地表和地下地质条件复杂,接收条件差,原始资料信噪比低,做剩余静校正前很难准确的识别有效速度,经过几次速度分析和剩余静校正后,才得到容易辨认的速度,但是由于初始速度和初始静校正量的误差问题,往往剩余静校正的迭代不是收敛的,得不到真实的地下构造形态。只有采用比较合理的求取初始速度方法,才能保证得到真实合理的成像。     

Modeling domestic holiday tourism demand in Australia: Problems and solutions

An econometric model is very useful for understanding the underlying relationship between tourism demand and economic variables such as income and travel prices. However, a long time series horizon of data is essential to run an econometric model that is consistent with economic theory. Although time series data on the number of domestic trips and visitor nights in Australia are available since 1978–79, breaks in the time series in different years have made it difficult to estimate a domestic holiday demand model. It is because the data series in different periods are not directly comparable. In this study, a simple data adjustment technique has been used to obtain comparable data series. Among several econometric demand models, a single equation multivariate time series demand model in a double log linear functional form was found to be the most appropriate and practical model to estimate and analyze the demand parameters of domestic holiday travel in Australia. However, the model with variables in level terms was observed having the “spurious regression problem” which has been corrected using the cointegration and error correction mechanisms. The estimated income and price elasticity of domestic holiday travel demand are consistent with economic theory and therefore can be used for forecasting and other purposes.     

我国沪深300股指期货价格发现功能的实证分析

我国股指期货的推出对证券市场产生了巨大的影响,改变了股票市场缺乏规避系统性风险工具的现状,给金融市场带来新的生机与活力。本文采用协整检验、误差修正模型、方差分解和脉冲响应函数实证分析了我国股票市场和期货市场的价格发现功能。研究发现股指期货在价格发现上占主导地位,表明我国股指期货的推出,增强了市场效率,使市场信息能够更快捷的传达。     

Cointegration analysis of the intensity of the ERM currencies under the European Monetary System

This paper examines the (long-run) intra-zonal elasticities between the spot exchange rates of the deutschemark and other major ERM currencies (French franc, Belgian franc, Dutch guilder, Danish krone, Italian lira and British pound) under the EMS. The findings show that under the fixed-but-adjustable rate system, the hypothesis of no cointegration can be rejected for all chosen ERM currency pairs and unit restriction on zonal elasticities can be accepted for almost all cointegrated currency pairs. On the other hand, under the fixed-rate system, Danish krone, Italian lira and British pound fail the cointegration test and the zonal elasticities for all cointegrated currency pairs are rejected to be unity. The study signifies less intense linkages of the ERM currencies without parity realignments. Finally, the deutschmark took the role of error-correcting process for one cointegrated currency pair under the fixed-but-adjustable-rate system, and it performed the same role for two pairs under the fixed-rate system. Hence, deutschmark should not be assumed a priori statistically exogenous under the EMS     

CBERS-2 CCD遥感图像辐射校正技术

在对CBERS-2卫星CCD遥感图像辐射校正技术进行深入研究的基础上,给出了图像的0级预处理、传感器标定、大气辐射校正、照度校正等技术方法。在0级图像预处理方面,提出了利用测试数据来解决拼接区的辐射失真问题,并提出一种新的条纹检测技术;传感器的标校方面,讨论了底电平和非均匀性的消除方法;大气辐射校正采用回归分析法和直方图法;给出了太阳高度和地形坡度的照度校正方法与技术。     

Origin 8软件在弹簧振子和惯性秤中的应用

采用Origin软件研究了惯性称和弹簧振子的振动周期T2和质量m的关系以及不同形状的弹簧修正系数C的关系。通过Origin软件拟合可以得到符合实验要求的光滑曲线,使得实验结果处理更加直观和简便。实验结果表明,弹簧的修正系数C和弹簧的形状有关,不具有普适性。     

TESTING FOR PURCHASING POWER PARITY AND UNCOVERED INTEREST PARITY IN THE PRESENCE OF MONETARY AND EXCHANGE RATE REGIME SHIFTS

Testing for purchasing power parity (PPP) and uncovered interest parity (UIP) has been the focus of many empirically oriented studies. While these simple economic theories of exchange rate and interest rate determination are theoretically attractive, the empirical support for these equilibrium conditions is at best mixed. Many potential reasons have been cited in the literature for the failure of such studies, ranging from market imperfections to inappropriate modelling strategies. The current state‐of‐the‐art procedure involves testing for two cointegrating vectors in a multivariate error correction model which may be economically identified as the PPP and UIP relations. However, such a procedure does not account for policy regime shifts which distort the underlying PPP and UIP relations. In this paper, a Markov‐switching vector error correction model (VECM) is considered for time series data in which monetary and exchange rate regime shifts are known to be present. Weak evidence in favour of PPP and UIP is established in a standard linear VECM, although the residuals of this model indicate that it is inappropriate in terms of functional form. The Markov‐switching VECM, however, provides convincing evidence in favour of both the PPP and UIP relations and a marked improvement in the residual distributions.     

基于电力用户用电信息采集系统中显示的特殊负荷曲线的错误接线方式的判定和分析

本文通过对电力用户用电信息采集系统中的一起特殊的负荷曲线理论分析与装置实际接线检查结果的对照,最后判定其接线错误方式,并计算出更正率,为电量退补提供了合理的依据,保证电量退补能够公平、公正地进行。     

一种基于B样条拟合的颜色校正方法

多重投影仪在大尺度显示系统中的解决颜色校正问题一直是比较棘手的,通过颜色色度匹配技术或者用分光光计来对投影仪进行颜色校正可以达到比较好的效果,但是这两种技术是基于硬件系统来实现的,成本相对高昂。通过三次B样条拟合方法进行多重投影仪颜色校正,不仅可以降低成本,同样能够达到一个比较好的效果。     

The Impact of Mobile App Adoption on Cross-buying: The Moderating Roles of Product Category Characteristics and Adoption Timing

With more and more companies introducing mobile apps and consumers using them during the purchase journey, it is increasingly important to understand the consequences of app adoption on behavioral outcomes. This paper investigates the impact of app adoption on the number of additional products purchased by customers (i.e., cross-buying) and how this effect varies across different product categories and different customers. We focus on two key product category characteristics (utilitarian vs. hedonic nature and perceived risk) and on adopters who vary in their adoption timings (early vs. late adopters). Using data from an online retailer and a combination of propensity score weighting with difference-in-differences and Heckman correction estimation techniques, the results show that app adoption has a positive effect on cross-buying overall, but the effect varies greatly across products and consumers. App adoption promotes additional product purchases for hedonic products but leads to less cross-buying for utilitarian products. In addition, early adopters purchase a higher number of additional product categories than late adopters, with this difference decreasing over time and for new consumers compared to existing customers. These results offer novel insights into the behavioral consequences of app adoption and provide managers with useful recommendations for improving the effectiveness of their mobile app investments.