一种16倍采样的Gardner定时同步方法

DVB-S2X(The second generation Digital Video Broadcasting by Satellite Extensions)标准给出了高至256阶的APSK(Amplitude Phase Shift Keying)调制方式，对解调端的符号定时同步、帧同步和载波恢复都提出了更高的要求。结合DVB-S2X技术手册的建议，在经典的基于4倍符号速率采样的Gardner定时同步的基础上，提出了一种在定时同步环路前端加预滤波器并将原来的单路插值扩展到4路插值的基于16倍采样的同步方法。介绍了该方法的思想和结构并进行了仿真实验，结果表明该方法相比于经典Gardner方法有更好的误码性能，在高阶调制的情况下表现尤为突出。     

Mutual fund liquidity timing ability in the higher moment framework

Using mutual fund data in Thailand, this study shows that fund managers can time the market-wide liquidity in the higher moment framework. High-performing fund managers demonstrate significantly positive liquidity timing ability, while low-performing fund managers do not. Thus, high-performing fund managers increase (decrease) the funds' exposure to the market during a high (low) market liquidity period, while low-performing fund managers do not show the liquidity timing ability. Moreover, only top-performing bank-related mutual funds possess the liquidity timing ability, supporting the information advantage hypothesis. Nonbank-related funds do not possess the liquidity timing ability at both the aggregate and portfolio levels. Several robustness tests confirm the findings.     

Productivity impacts of infrastructure development in Asia

This study investigates the impact of infrastructure capital on total factor productivity in selected Asian countries. The scope of the assessment is broadened by exploring the effect of infrastructure development on sectoral differences in total factor productivity. The study calculated the total factor productivity over the period 2006–2016 for 16 manufacturing industries in 19 Asian countries. Further, the impact of lagged infrastructure and endowment is also explored with an eye toward improving different infrastructural measures. The empirical findings show that lagged infrastructure and endowment exert a positive and significant impact on infrastructural improvement. The impact of telecommunications, road, and power infrastructure on sectoral productivity is investigated by applying the fully modified ordinary least squares estimation technique to control the endogeneity problem associated with infrastructure provision. Overall, the empirical findings show that infrastructure provision, particularly the provision of telecommunications and power, is an important factor for explaining patterns of comparative advantage, whereas the provision of roads is important to explain patterns of absolute advantage. The results further indicate that road infrastructure is more important for low technology-intensive industries, while power infrastructure is crucial for high technology-intensive industries.     

Waiting and following: Within-industry herding behavior in annual report disclosure

Using the unique scheduled disclosure system for annual reports in China’s stock market, we examine within-industry herding behavior in annual report timing. The results reveal the waiting and following behavior strategies used in the annual reporting process within industry. Firms that originally schedule an early (late) disclosure date within their industry are more likely to reschedule to a later (earlier) date. Informational pressure is the dominant mechanism underlying herding in annual reporting, and capital market reputation incentives mainly induce the herding of bad news. Further analysis shows that delaying disclosure via the waiting strategy reduces the future occurrence of restatements, whereas bringing forward disclosure does not change the propensity of future restatements. Overall, we enrich the limited empirical studies on sequential mandatory disclosure decisions within industry.     

The market timing of corporate bond reopenings

The objective of this paper is to test whether companies use corporate bond reopenings to exploit overvalued debt. Reopenings represent new debt offerings, which are characterized through identical configurations as an already outstanding bond, but with a market-adjusted price. Their advantage lies with the fact that fewer preparations are required compared to a new regular offering. For a set of European companies our results suggest that stockholders respond less positively to the announcements of reopenings than to regular offerings. This effect is stronger, the higher the pre-issue bond price run-up, and the stock price reaction is directly linked to the change in the firm’s debt value. Additionally, the prices of the reopened bonds drop on the announcement day. Therefore, in line with the window of opportunity theory, the firm’s management appears to use reopenings as a fast and inexpensive way to raise debt capital, which leads stockholders and bondholders to suspect an overvaluation and therefore to adjust their price expectations. The analysis also reveals that the redistribution of wealth from bondholders to stockholders is a major determinant for the observed price changes.     

Earnings announcement timing,uncertainty, and volatility risk premiums

We examine the relationship between firms’ quarterly earnings report timing and uncertainty before quarterly earnings announcements. Prior research provides conflicting predictions on how investor uncertainty and report timing are related. Using implied volatilities from equity options and the realized returns to straddle positions, we find evidence that uncertainty and volatility risk premiums are higher for firms that report later in the quarter. Further tests show that the increase in option premiums is unexplained by risk factors suggesting a mispricing by investors. These results are not associated with static firm-level factors and our findings are concentrated in high growth firms.     

一种采用可变同步帧的OFDM符号定时同步算法

符号定时同步是正交频分复用（Orthogonal Frequency Division Multiplexing,OFDM）系统中最为关键的同步之一。针对现有的基于数据辅助类的同步算法中帧头存在持续时间长、抗噪声性能差和对载波频偏敏感等问题，提出了一种可变长度的同步帧结构，采用滑动差分相关算法完成符号定时同步。仿真结果表明，提出的同步帧结构持续时间短于一个OFDM符号周期，并且训练序列长度可以通过估算信噪比大小而灵活控制。同时，所提算法在归一化载波频偏为12（远远超过晶振的误差范围 ±10-5）的情况下正常工作；在高斯白噪声和多径衰落信道中都有较好的性能，且其流水线结构易于硬件实现。     

When are ‘sharks’ beneficial? Corporate venture capital investment and startup innovation performance

The effect of corporate venture capital (CVC) investment on startup innovation performance has been examined in the extant literature. However, when this effect is enhanced is the important but relatively understudied question in strategy and entrepreneurship research. We build on the idea of regarding CVC investment relationships as learning alliances and introduce two situational factors as boundary conditions on the performance effect of CVC investment. In order to handle the endogeneity of CVC investment, we employ propensity score matching and differences-in-differences techniques. Based on the sample of startups in the human biotechnology industry in the United States, we find that CVC funding is beneficial for startup innovativeness when CVC investment is established after initial independent venture capital funding. Moreover, a startup’s patent stock before CVC funding also influences on that effect.     

Disentangling the role of variance and covariance information in portfolio selection problems

The covariation among financial asset returns is often a key ingredient used in the construction of optimal portfolios. Estimating covariances from data, however, is challenging due to the potential influence of estimation error, specially in high-dimensional problems, which can impact negatively the performance of the resulting portfolios. We address this question by putting forward a simple approach to disentangle the role of variance and covariance information in the case of mean-variance efficient portfolios. Specifically, mean-variance portfolios can be represented as a two-fund rule: one fund is a fully invested portfolio that depends on diagonal covariance elements, whereas the other is a long-short, self financed portfolio associated with the presence of non-zero off-diagonal covariance elements. We characterize the contribution of each of these two components to the overall performance in terms of out-of-sample returns, risk, risk-adjusted returns and turnover. Finally, we provide an empirical illustration of the proposed portfolio decomposition using both simulated and real market data.     

Effects of loyalty program rewards on store loyalty

This investigation examines consumers' preferred loyalty program (LP) designs across two retail contexts, grocery retailing and perfumery, with varying degrees of personal involvement. The research employs in-store full profile conjoint analysis by using the following attributes: timing of the reward, reward compatibility with the store's image, and tangibility.Our research reveals that the underlying effects of reward types on preferences and intended store loyalty differ depending on the level of consumers' personal involvement. In sectors with high personal involvement, compatibility with the store's image and intangible rewards increase LP preference and loyalty intentions. The time required to obtain the reward (immediate/delayed) has no impact. In sectors with low personal involvement, immediate and tangible rewards increase LP preference and loyalty intentions. Compatibility with the store image has no impact.