Testing the capital asset pricing model efficiently under elliptical symmetry: a semiparametric approach

We develop new tests of the capital asset pricing model that take account of and are valid under the assumption that the distribution generating returns is elliptically symmetric; this assumption is necessary and sufficient for the validity of the CAPM. Our test is based on semiparametric efficient estimation procedures for a seemingly unrelated regression model where the multivariate error density is elliptically symmetric, but otherwise unrestricted. The elliptical symmetry assumption allows us to avoid the curse of dimensionality problem that typically arises in multivariate semiparametric estimation procedures, because the multivariate elliptically symmetric density function can be written as a function of a scalar transformation of the observed multivariate data. The elliptically symmetric family includes a number of thick‐tailed distributions and so is potentially relevant in financial applications. Our estimated betas are lower than the OLS estimates, and our parameter estimates are much less consistent with the CAPM restrictions than the corresponding OLS estimates. Copyright © 2002 John Wiley & Sons, Ltd.     

Calibration of stochastic volatility models: A Tikhonov regularization approach

We aim to calibrate stochastic volatility models from option prices. We develop a Tikhonov regularization approach with an efficient numerical algorithm to recover the risk neutral drift term of the volatility (or variance) process. In contrast to most existing literature, we do not assume that the drift term has any special structure. As such, our algorithm applies to calibration of general stochastic volatility models. An extensive numerical analysis is presented to demonstrate the efficiency of our approach. Interestingly, our empirical study reveals that the risk neutral variance processes recovered from market prices of options on S&P 500 index and EUR/USD exchange rate are indeed linearly mean-reverting.     

第四方物流下的供应链选择

利用供应链运作参考模型（SCOR）第一层的指标作为评判指标体系，并将它们与供应链关系指标综合考虑，采用模糊层次分析法（Fuzzy AHP）来解决每条供应链的多层次和MCDM问题，并耳最终得到对供应链的最优选择。     

Determinants of credit to households: An approach using the life-cycle model

This paper applies a life-cycle model with individual income uncertainty in order to investigate the determinants of credit to households. We show that the household credit to GDP ratio depends on the lending-deposit interest rate spread, individual income uncertainty, and individual income persistence. We subsequently provide empirical evidence for the prediction of a theoretical model on the basis of data from OECD and EU countries.     

A decision analysis model for smart mobility system development under circular economy approach

Circular economy (CE) is recognized as one of the most popular theories of the decade. Its domain spreads to disciplines like production, environmental sciences, and transport/mobility sectors. This research corresponds to one of the essential questions in CE which look for effective solutions in smart mobility systems regarding eco-innovation indicators. We conducted a deep survey on CE and smart mobility literature and sorted out potential solutions (alternatives) and fundamental indicators based on the Quintuple Helix model. Then, a rough-based multiple criteria decision analysis model was adopted by the incorporation of LMAW (logarithm methodology of additive weights) and MARCOS (measurement of Alternatives and Ranking according to the COmpromise Solution) methods. To analyse the potential solutions, ten experts from relevant sectors assisted us in composing an assessment platform through qualitative comparison. Initial results showed that public transport (good practices) and shared mobility services are amongst the best solutions for establishing a smart mobility plan. Our decision-making model was tested and showed that our ranking scores are highly confidential and stable. The outcome of this study can be benchmarked in urban planning, where policymakers should rethink the transport and mobility sectors, structuring, development, and economic remodelling which are top decision-making problems nowadays.     

The theta model: a decomposition approach to forecasting

This paper presents a new univariate forecasting method. The method is based on the concept of modifying the local curvature of the time-series through a coefficient ‘Theta’ (the Greek letter θ), that is applied directly to the second differences of the data. The resulting series that are created maintain the mean and the slope of the original data but not their curvatures. These new time series are named Theta-lines. Their primary qualitative characteristic is the improvement of the approximation of the long-term behavior of the data or the augmentation of the short-term features, depending on the value of the Theta coefficient. The proposed method decomposes the original time series into two or more different Theta-lines. These are extrapolated separately and the subsequent forecasts are combined. The simple combination of two Theta-lines, the Theta=0 (straight line) and Theta=2 (double local curves) was adopted in order to produce forecasts for the 3003 series of the M3 competition. The method performed well, particularly for monthly series and for microeconomic data.     

A profitable model for predicting the over/under market in football

The over/under 2.5 goals betting market allows gamblers to bet on whether the total number of goals in a football match will exceed 2.5. In this paper, a set of ratings, named ‘Generalised Attacking Performance’ (GAP) ratings, are defined which measure the attacking and defensive performance of each team in a league. GAP ratings are used to forecast matches in ten European football leagues and their profitability is tested in the over/under market using two value betting strategies. GAP ratings with match statistics such as shots and shots on target as inputs are shown to yield better predictive value than the number of goals. An average profit of around 0.8 percent per bet taken is demonstrated over twelve years when using only shots and corners (and not goals) as inputs. The betting strategy is shown to be robust by comparing it to a random betting strategy.     

Growth versus profit-maximization: A simultaneous-equations approach to testing the marris model

This paper adopts a new approach to the empirical testing of the Marris managerial theory of the firm and applies it to a cross-section sample of British companies in the early 1970s. It introduces three important innovations in the direct testing of the model: (i) a new exposition of the Marris theory if presented leading to a specification of the model as a simultaneous system; (ii) ownership control is measured as a continuous variable; (iii) the location of control is identified as an important dimension in the analysis. Preliminary estimates cast doubt on some important assumptions of the Marris theory.     

Calibration of a model of declining prices in cattle auctions

Using data from dairy cattle auctions plus independent appraisals of the cattle sold, this paper is able to verify the existence of the “declining price anomaly”: prices decline over the course of the auction, with the main decline occurring towards the end of the day. We show that the data are consistent with a simple model of sequential auctions of goods with independent values, and examine distributions which replicate the important features of the data. The crucial feature driving the price declines in the model is a limited capacity for purchases by the participants in the auction, which in turn decreases competition for the final units in the auction.     

三菱FX2N系列PLC对X62W铣床的改造

文章介绍了利用三菱FX2N系列PLC对X62W铣床的改造,阐述了系统改造方案,同时根据X62W铣床的控制要求和特点,确定PLC的输入输出分配,在继电器控制线路的基础上,设计出梯形图并进行现场调试。     

A set optimization approach to utility maximization under transaction costs

A set optimization approach to multi-utility maximization is presented, and duality results are obtained for discrete market models with proportional transaction costs. The novel approach allows us to obtain results for non-complete preferences, where the formulas derived closely resemble but generalize the scalar case.     

The RWDAR model: A novel state-space approach to forecasting

This paper introduces the Random Walk with Drift plus AutoRegressive model (RWDAR) for time-series forecasting. Owing to the presence of a random walk plus drift term, this model shares some similarities with the Theta model of Assimakopoulos and Nikolopoulos (2000). However, the addition of a first-order autoregressive term in the state equation provides additional adaptability and flexibility. Indeed, it is shown that RWDAR tends to outperform the Theta model when forecasting both stationary and nearly non-stationary time series. This paper also proposes a simple estimation method for the RWDAR model based on the solution of the algebraic Riccati equation for the prediction error covariance of the state vector. Simulation results show that this estimator performs as well as the standard Kalman filter approach. Finally, using yearly data from the M3 and M4 competition datasets, it is found that RWDAR outperforms traditional forecasting methods.     

Run length analysis of Shewhart charts applied to drifting processes under an integrative SPC/EPC model

Engineering Process Controllers (EPC) are frequently based on parametrized models. If process conditions change, the parameter estimates used by the controllers may become biased, and the quality characteristics will be affected. To detect such changes it is adequate to use Statistical Process Control (SPC) methods. The run length statistic is commonly used to describe the performance of an SPC chart. This paper develops approximations for the first two moments of the run length distribution of a one-sided Shewhart chart used to detect two types of process changes in a system that is regulated by a given EPC scheme: i) changes in the level parameter; ii) changes in the drift parameter. If the drift parameter shifts, it is further assumed that the form of the drift process changes from a linear trend under white noise (the in-control drift model) into a random walk with drift model. Two different approximations for the run length moments are presented and their accuracy is numerically analyzed. Received: August 1998     

Order flow in the South: Anatomy of the Brazilian FX market

This paper analyses one of the main pillars of Brazil's newly found economic resilience: a maturing FX market providing support to its managed floating exchange rate regime. I develop a microstructure model suitable to describe the Brazilian FX market, an emerging economy frequently subjected to sudden stops in capital flows. The model introduces two major changes relative to previous microstructure models. First, dealers may decide to hold overnight positions in the FX market if they find it profitable to do so. Second, customers’ demand for foreign exchange is a function of macroeconomic fundamentals, including contemporaneous feedback from exchange rate movements. The main predictions of the model are supported by a unique data set, covering all transactions between dealers and customers from the official Brazilian FX market from July 1, 1999 to June 30, 2003 (a time period in which Brazil suffered two severe external liquidity shocks).     

How to improve a technology evaluation model: A data-driven approach

Academic research suggests a number of technology evaluation models. To ensure effective use, models need to be improved in accordance with changing internal and external environments. However, a majority of previous studies focus on model development, while a few emphasize their implementation or improvement. To fill this research gap, this study suggests a systematic approach to examining the validity of technology evaluation models and improving them. We consider three propositions as criteria for improvement: 1) the coherence of the evaluation results with the evaluation purpose, 2) the appropriateness of the evaluation methods, and 3) the concreteness of the evaluation model. Rather than using expert opinions, this study takes a data-driven approach, wherein we analyze actual evaluation results and determine whether the model produces the intended results. A case study of 291 technology evaluation results, all made by the South Korean government in support of technology-based small and medium-sized enterprises, is conducted to verify the suggested approach's applicability. This is one of the few studies to address issues regarding improvements to a technology evaluation model. Its approach can help to develop and continuously improve a valid technology evaluation model, thus leading to more effective practice.     

基于FX2N-1PG定位控制的工业机器人的行走系统研究

本文介绍了一种针对工业机器人行走的自动化控制解决方案,为工业机器人底座配置了可直线运动的机械轴运动系统和步进电机,使用了三菱可编程控制器以及增设模组FX2N-1PG来与工业机器人做好通讯,并为步进电机提供脉冲,配合工业机器人的机械臂运动,使工业机器人在装配位与加工位之间进行行走。文中介绍了机器人与控制设备之间的通讯,软硬件连接方法。     

A new approach to estimating a profit frontier using the censored stochastic frontier model

The translog profit functional form is widely used to study technical efficiency for banks. Although this functional form is known as being flexible, it is not applicable to those banks incurring economic losses. The recently developed approach, i.e., the censored stochastic frontier model (CSFM), by Tsay et al. (2013) appears to be superior to existing approaches, since CSFM does not need to transform negative profit into positive profit before taking the natural logarithm. The transformation with respect to the profit variable tends to bias the parameter estimates of the profit frontier and the subsequent profit efficiency measure. We show that the parameter estimates of CSFM have the desirable statistical properties. Moreover, empirical results reveal that the mean profit efficiency of CSFM is more robust than those models using transformed profits across the sub-periods 1991–1998 and 1999–2009.     

重合闸在4/3断路器接线中的应用分析

文章介绍了现代徽机保护中的自动重合闸装置,结合4/3断路器接线方式下的自动重合闸与保护的配合情况及现场实际,阐述了4/3断路器接线方式下重合闸选型、运行操作及注意事项。