管理信息系统中在线帮助子系统设计

在线帮助是数据库管理系统的重要组成部分。本文以 Foxpro2.0为基础讨论了面向应用的在线帮助子系统的几种设计方法。     

Value Relevance of Fair Values—Empirical Evidence of the Impact of Market Volatility

This study examines empirically the effects of market volatility on the value relevance of fair values. Using the modified Ohlson model ( 1995 ) and a sample of U.S. financial companies for the period of 2008 to 2013, this study shows that fair values are priced at a significant discount when market volatility is high. Song ( 2013 ) shows analytically that the effectiveness of fair value accounting is negatively affected by market volatility. Findings of the current study suggest that investors understand the effects of market volatility on fair values and price them accordingly. The study extends the research on the determinants of the usefulness of fair values by looking beyond factors associated with the reliability of estimated fair values (Level 2 and Level 3 fair values). This study has practical implications: current accounting standards for fair value measurement acknowledge the limitations of the market as a source of fair values by offering a three‐level fair value hierarchy with provisions for fair values to deviate from market prices. Findings of this study shed light on a previously little studied factor, that is, market volatility, on the usefulness of fair values.     

开市前议价期流动性形成的理论分析

股市开市前议价期存在于世界一些主要证券交易所。投资者可以在这段时间内自由地、无成本地提交、修改或者撤销不受限制的交易指令。在信息不对称和流动性提供者参与市场必须支付成本的假设下,我们构建一个简单模型,考察了存在和术存在开市前议价期两种市场机制下的流动性形成情况。定义了这个模型的均衡解,证明了开市前议价期提高了市场流动性和社会福利。     

产品差异理论研究的新动向

产品差异是产业组织理论中非常重要的研究领域之一,但是我国产业经济学界对产品差异的研究相对薄弱,因此本文将从信息差异、策略性差异和存在网络外部性情况下的产品差异三方面阐述产品差异理论研究的最新进展,希望对我国产品差异理论的研究有所启迪。     

Automate the identification of technical patterns: a K-nearest-neighbour model approach

To explore profitable patterns in historical stock prices, ordinarily a promising pattern is selected by rule of thumb, and then its performance is verified by comparing the conditional return of the pattern with the unconditional benchmark return. We adopt an alternative philosophy: without any pre-selected pattern, the proposed method explores the entire graphic space to automate the identification of technical patterns. Derived from the K-nearest-neighbour (KNN) forecast, our method calculates the graphic similarity of patterns by the distance of the price vectors, and then classifies patterns according to the graphic similarity, and finally identifies patterns which contain predictive powers of the future market movement. KNN provides an excellent tool for probing the entire graphic space formed by price patterns to obtain an overall perspective of the effectiveness of technical patterns. Not only the well-known patterns but also the unnoticed and potentially informative patterns can be probed. To evaluate the performance, our method is compared with classic KNN forecast and technical trading rules. Results indicate that the stock market is relatively efficient and technical analysis is still effective to explore excess returns.     

Mixed-effects models for health care longitudinal data with an informative visiting process: A Monte Carlo simulation study

Electronic health records are being increasingly used in medical research to answer more relevant and detailed clinical questions; however, they pose new and significant methodological challenges. For instance, observation times are likely correlated with the underlying disease severity: Patients with worse conditions utilise health care more and may have worse biomarker values recorded. Traditional methods for analysing longitudinal data assume independence between observation times and disease severity; yet, with health care data, such assumptions unlikely hold. Through Monte Carlo simulation, we compare different analytical approaches proposed to account for an informative visiting process to assess whether they lead to unbiased results. Furthermore, we formalise a joint model for the observation process and the longitudinal outcome within an extended joint modelling framework. We illustrate our results using data from a pragmatic trial on enhanced care for individuals with chronic kidney disease, and we introduce user-friendly software that can be used to fit the joint model for the observation process and a longitudinal outcome.     

E-satisfaction and continuance intention: The moderator role of online ratings

Given the growing importance of SNSs (social networking sites) in the online decision-making process, the authors present a new applied theory of motivation. Drawing from gratification theory, this study develops a causality model that links online informative motivation (OIM), e-satisfaction, and online ratings to guarantee the online customer’s continuance intention. Although the partial least squares (PLS) findings extracted from a representative sample of 313 hotel customers confirm substantial positive linkages among the above constructs within this causality model, fuzzy set/qualitative comparative analysis (fsQCA) results take it one step further by reinforcing and refining the existing findings in the contexts of high and low levels of online ratings. Accordingly, implications for theory and practice, as well as research limitations and directions for future research are also discussed.     

纵向差异化下的双寡头信息性广告竞争模型

本文以Butters(1977)关于信息性广告的开创性模型为基础,引入Mussa和Rosen(1978)提出的纵向差异化分析模型,借鉴泰勒尔(1997)基于Grossman和Shapiro(1984)模型改进基础上的对横向差异化下的双寡头信息性广告竞争的分析方法,建立了一个纵向差异化下的双寡头信息性广告竞争模型。我们通过Matalab软件计算了模型的数值解,得出结论:(1)均衡时,高质量产品生产企业的价格、广告与利润水平较高;(2)纵向差异化程度越高,均衡时,企业价格越高,做广告越多,利润越大;(3)做广告的成本越高,均衡时,企业做广告越少,价格越高,利润越大。     

功能翻译理论下的高校外事翻译方法研究

本文分析了高校外事文本的语篇类型,外事文语篇兼具信息功能和呼唤功能,结合功能翻译理论分析外事翻译的特点,采取了交际翻译方法、编译法等方法,实现高校外事语篇的在目的语言中的功能对等,达到对外交流合作的预期效果。同时,也为外事翻译中译者主体性的发挥提供一个度的参考。