我国基金风格资产收益长记忆性分析——基于修正R/S方法的研究

证券市场是个典型的非线性复杂系统。本文运用修正R/S分析法对我国基金风格资产收益单一分形的基本统计特征进行检验,并与经典R/S方法进行对比分析。研究结果表明:在日、周、月等三种时间标度下Hurst指数均显著大于0.5,表现为持久相关性特征,说明股市风格具有长记忆性;从经典R/S分析结果看,我国股市风格具有显著的分形结构特征,风格资产指数收益率序列具有长记忆性,不同风格资产的业绩具有不同的周期性。     

Mixture of MLP-experts for trend forecasting of time series: A case study of the Tehran stock exchange

A new method for forecasting the trend of time series, based on mixture of MLP experts, is presented. In this paper, three neural network combining methods and an Adaptive Network-Based Fuzzy Inference System (ANFIS) are applied to trend forecasting in the Tehran stock exchange. There are two experiments in this study. In experiment I, the time series data are the Kharg petrochemical company’s daily closing prices on the Tehran stock exchange. In this case study, which considers different schemes for forecasting the trend of the time series, the recognition rates are 75.97%, 77.13% and 81.64% for stacked generalization, modified stacked generalization and ANFIS, respectively. Using the mixture of MLP experts (ME) scheme, the recognition rate is strongly increased to 86.35%. A gain and loss analysis is also used, showing the relative forecasting success of the ME method with and without rejection criteria, compared to a simple buy and hold approach. In experiment II, the time series data are the daily closing prices of 37 companies on the Tehran stock exchange. This experiment is conducted to verify the results of experiment I and to show the efficiency of the ME method compared to stacked generalization, modified stacked generalization and ANFIS.     

Endogenous fertility and modified Pareto-optimality

In a world of endogenous fertility, where the number of descendants is an integral part of the economic allocation, the traditional concept of Pareto-optimality cannot be applied any longer: the number of individuals to be present on earth may vary between any two allocations we wish to compare. Therefore, the concept needs to be modified in order to give new life to the discussion of economic efficiency. This work introduces a straightforward variation of the Pareto-principle and characterizes the optimality of economic allocations according to this concept. It is shown that some of the well-known traditional results on intertemporal optimality do no longer hold. In particular, lump-sum tax instruments (or the rearrangement of initial endowments) are no longer a sufficient tool to achieve efficiency. Received: March 2003, Accepted: September 2005 This work has greatly benefitted from comments by Oded Galor, Karl Shell, Vasco Santos and an excellent anonymous referee. Many thanks to the Editor of this Journal for providing an impeccable refereeing process. Support by the European Union via the Human Capital and Mobility Grant #ERBCHBICT941218 is gratefully acknowledged.     

Trading activity and price discovery in Bitcoin futures markets

This study examines the impact of trading activities on price discovery in the Bitcoin futures markets. We find that trades of hedgers are positively correlated with the modified information shares in both CME and CBOE futures markets, suggesting that their trading promotes futures market efficiency. Retailers’ trading activity relates negatively to the price discovery of the CME Bitcoin futures and thus destabilizes the market. Speculators exert positive (negative) impact on the price discovery in the CME (CBOE) Bitcoin futures. Our finding that CME’s Bitcoin futures exhibit superior price discovery than CBOE’s provides plausible justification for CBOE’s decision in March 2019 to suspend further listings of Bitcoin futures contracts.     

Why do you use Yelp? Analysis of factors influencing customers’ website adoption and dining behavior

The number of review websites has increased within the past years since more people rely on online reviews to help their decision-making process. Previous studies have either focused on the attributes of the content posted on review websites (i.e., reviews) or customers’ behavior concerning their selection of review website on which to post reviews. This study, however, extends the Technology Acceptance Model (TAM) to investigate the factors that influence individuals’ restaurant review website adoption behaviors to read reviews and make dining decisions. In addition, this study will look at the differences in individuals’ perceptions of various restaurant review websites (i.e., Yelp vs. others). The findings revealed the role of influential factors on individuals’ review website adoption and dining decisions as well as the differences in proposed structural relationships among various restaurant review websites.     

20 years of research on virtual reality and augmented reality in tourism context: A text-mining approach

Virtual reality (VR) and Augmented Reality (AR) have undergone technical evolutions over the last few decades including improvements in immersion and the feeling of telepresence. Several examples of the applications of such techniques can be found in stores, tourism, hotel, restaurants, and destinations. Yet, a comprehensive analysis of studies employing such techniques in tourism-related studies is difficult to find. The current study uses citation network analysis and text-mining techniques to conduct a full-text analysis of 56 journal papers and 325 conference proceedings related to VR and AR in the tourism context. This paper intends to (i) provide an overview of the VR and AR-related tourism studies network and discuss them over time, (ii) present the most important topics and studies emerging from this literature, (iii) suggest avenues for further research. Findings reveal 10 core topics in journal papers and 11 core topics in conference proceedings, which are presented together with an overview of the published studies and the main authors.     

Exploring the acceptance of instant shopping – An empirical analysis of the determinants of user intention

This article deals with the novel technology of instant shopping. As this technology has yet to be considered in a scientific context, the article first defines the term instant shopping, distinguishing it from m-commerce and s-commerce. The article then gives an overview on acceptance studies in the context of e-commerce that have been conducted over the last five years. Building on this, the Technology Acceptance Model (TAM) is adapted and operationalized for the current context. One result of the study in this article, conducted among Instagram users on the topic of instant shopping, showed that perceived enjoyment has a particularly strong impact on the intention to use.     

直播电商情境下的消费者行为研究——基于TAM/TPB模型

直播电商作为一种新型的电子商务模式,在释放消费潜力、促进产业融合、推动创新创业等方面都发挥着重要作用。基于技术接收模型(TAM)、计划行为理论(TPB)以及信任理论,建立结构方程模型,对直播电商消费者行为展开实证研究。研究结果表明,感知有用性、信任、主观规范均显著性正向影响消费者使用意向,此外,感知易用性和信任对感知有用性也存在显著性正向影响。     

探索3G业务使用意愿的影响因素研究——以苏北地区在校大学生为例

随着信息产业部授予中国移动、中国联通、中国电信等三大通信公司移动通信服务许可证,酝酿已久的中国3G时代拉开帷幕。基于技术接受模型（TAM）、创新扩散理论以及移动性研究,建立3G业务使用意愿影响因素模型,通过对苏北地区在校大学生进行抽样调查,使用SPSS12.0进行数据分析,并建立回归方程进行验证,探究3G业务使用意愿的影响因素。     

基于消费者购买决策过程优化购物网站的功能及营销策略

目前我国网络购物交易得到了快速的增长,然而购物站点设计的不合理却制约了网购市场的蓬勃发展。购物网站必须围绕消费者的购买决策过程来优化站点的功能、设计营销的策略,运用TAM理论、全程贯彻体验营销、完善站点内外的搜索功能,从而促进购买决策各个阶段的转化和开展,提高网络购物转化率。