Chief Audit Executive as Supervisory Board Member and Executive Compensation Contracts

This paper studies a unique phenomenon in China's corporate governance—that chief audit executives (CAEs) sit on supervisory boards (CAE duality)—and examines its effects on executive compensation contracts. Using a sample of listed firms between 2010 and 2018, we find a significant positive relation between CAE duality and pay-for-performance sensitivity, which suggests that the dual position helps integrate monitoring resources and reduces agency costs. This positive relation is more pronounced when companies face a stricter monitoring environment and in non-state-owned enterprises (non-SOEs) than in SOEs. In addition, we find that the recent reforms on compensation strengthen the role of CAE duality in SOEs. Further analysis identifies the reliability of performance information (i.e., earnings quality) and reduced executive self-interested behaviours (i.e., perquisite consumption) as the influencing mechanisms that increase the demand for performance-based compensation and thus improve pay-for-performance sensitivity.     

Short-sale constraints and informational efficiency to private information: A natural experiment

Exploiting a regulatory change in short-sale constraints (Regulation SHO) as a natural experiment, this paper examines the effect of short-sale constraints on informational efficiency of stock prices to private information. I find that short-sellers act as informed traders prior to forthcoming analyst news and trade on negative private information. When short-sale constraints are relaxed for pilot stocks (treatment group), both trading volume and stock price sensitivity increase prior to the analyst announcement for bad news but not for good news, relative to that of nonpilot stocks (control group). The findings are consistent with the Diamond and Verrecchia model that predicts that short-selling increases the speed of adjustment of stock prices to private negative information. In the cross-section, the effect of Reg SHO is stronger in stocks of firms with weak and uncertain information environments (i.e., small firms and firms with high analyst forecast dispersion).     

Institutional quality,investment efficiency,and the choice of public–private partnerships

We examine a sample of 625 public–private partnership (PPP) firms from 1980 to 2015 that straddle nine countries with varying degrees of economic development and PPP markets. We find that the motivations of the firms that undertake PPP investments vary. While private sector firms in economies with low institutional quality choose to engage in PPPs to alleviate capital constraints attributed to underinvestment, those in economies with high institutional quality participate in PPPs to solve the problem of overinvestment due to an abundant cash flow. In the long run, the benefits of lower capital constraints through PPP investments are more pronounced in economies with high institutional quality.     

Disappearing investment-cash flow sensitivities: Earnings have not become a worse proxy for cash flow

According to a recent conjecture in the literature, earnings have become a poorer proxy for cash flow from operations over time. We find that since 1988, when cash flow statements started to be consistently reported in Compustat, the cash effectiveness of earnings has actually increased for a large sample of US manufacturing firms. This occurs despite the introduction of fair value accounting and increasing accounting accruals during the last three decades. Also contrary to the conjecture, using more comprehensive measures of cash flow does not restore the investment-cash flow sensitivity, which continues to be around 0.05 in more recent periods.     

探地雷达在公路改扩建工程检测中的应用

公路改扩建工程在广东省正处于快速发展时期,如何准确得到路面病害情况,是旧路处治方案制定面临的主要问题.依托开阳高速改扩建工程,采用三维探地雷达对旧路进行病害检测,得到道路表面及内部的病害分布情况,并分别与人工徒步调查路况及开挖后内部实际情况进行比对.结果表明:当三维探地雷达检测采样间距设置为2.0 cm、驻波时间设置为0.6 ms、时窗设置为85 ns时,可达到较好的检测精准度;三维探地雷达可实现对路面结构内部不同深度位置的裂缝病害进行探测,精确识别3 mm宽裂缝,并了解裂缝的发展方向及性质.     

The impact of investor structure on stock price crash sensitivity: Evidence from China's stock market

Stock price crash sensitivity refers to the conditional probability of a stock crash when the market collapses. It focuses on individual stocks' sensitivity to the market crash and can affect stock pricing significantly. Although the crash sensitivity of China's stock market is very high as a whole (Weigert, 2016), different individual stocks show varying degrees of crash sensitivity. This paper, adopting the perspective of institutional investors, explores the reasons for the difference in crash sensitivity in China's stock market, and finds that: First, institutional investors' shareholdings is positively related to firms' stock price crash sensitivity. However, after dividing institutional investors into professional (represented by financial institutions) and non-professional institutional investors (represented by general legal persons), we find that only professional institutional investors' shareholdings is negatively related to firms' stock price crash sensitivity. Second, the impact of professional institutional investors on the crash sensitivity is influenced by stock liquidity and media sentiment: when the stock liquidity of listed companies is good or the media sentiment is strong, the negative impact of professional institutional investors on the crash sensitivity is accordingly high. This paper, by highlighting the investor structure, attempts a pioneering exploration of the influencing factors of the difference in stock price crash sensitivity in China. Our empirical results enrich research on stock price crash sensitivity and the heterogeneity of institutional investors. They can also serve to guide regulatory authorities' development of institutional investors and efforts to maintain market stability.     

地下综合管廊混凝土爆灰检测及加固

针对某市钢筋混凝土地下综合管廊的现浇顶板、侧壁出现的混凝土爆灰质量缺陷,为确保管廊结构的安全使用,采用钻心法、超声波法、沸煮试验、爆灰物质的化学成分分析等检测方法,对爆灰现象进行了检测。结果显示,混凝土中存在的块状氧化钙与水熟化后体积增大1倍~2.5倍,使得混凝土在强度未达到设计抗拉强度前在块状氧化钙体积膨胀应力作用下被拉裂,导致了此类质量缺陷的发生。分析了质量缺陷对管廊结构的影响,并对管廊结构进行了加固设计及处理,满足了结构的正常安全使用要求。研究结果可为类似爆灰缺陷的设计及处理提供参考。     

一种经验模式分解下的海杂波小目标检测方法

利用海杂波有效探测海上小目标是目前雷达探测领域的热点问题，具有重要的应用价值。鉴于海杂波是一种非线性非平稳性的雷达回波信号，充分发挥整体平均经验模式分解的优势，将海杂波分解为若干个不同尺度的独立分量。通过研究发现有目标时，分解出的前5个分量与未分解前信号的相关系数明显减小，因此提出了一种新的海杂波背景下的目标检测方法。通过实测和模拟的海杂波数据进行训练和测试，研究结果表明，该方法能有效地实现海杂波下目标的探测，性能优于经典时域下、分数阶傅里叶变换域下以及平均经验模式分解后的广义Hurst指数的目标检测方法。     

广义空间调制系统的正则化OMP检测算法

在广义空间调制（GSM）系统中，最大似然（ML）检测可以取得最优的检测性能，然而其计算复杂度随激活天线数的增加急剧增长。针对这一问题，提出了一种基于稀疏重构理论的低复杂度检测算法——正则化正交匹配追踪（ROMP）算法。该算法首先根据信道矩阵和当前残差的内积选取多个候选激活天线索引，接着对候选天线索引按正则化标准进行可靠性验证，剔除错误索引，缩小信号的搜索空间，最后通过求解最小二乘问题估计信号。仿真结果表明，与经典的正交匹配追踪（OMP）算法相比，所提算法以少许复杂度的增加为代价极大提升了检测性能，能够在检测性能与复杂度之间取得更好的折中。     

剖线强度梯度变化的作物软硬变化区精确划分

[目的]软硬变化区的划分是进行遥感变化检测技术识别农作物的基础。为解决人工判读方法中存在人为主观因素影响以及自动判别和交互式判别方法对不同研究区的适用性问题,该文提出基于剖线梯度变化(Profile based Gradient Change Magnitude,PGCM)进行软硬变化区划分的方法。[方法]该研究选择破碎农业景观种植区域为研究区,计算拔节期Quick Bird影像和播种期模拟影像两个时相的变化强度,从作物地块内部向外绘制剖线,利用剖线强度的梯度变化确定硬变化区(Hard change region,HCR)、软变化区(Soft change region,SCR)和未变化区(Non change region,NCR)3者间的划分阈值。[结果]从识别结果来看,PGCM能够有效在地块边界处探测到软变化像元,进而确定HCR、SCR。像元分辨率在5~60 m不同尺度下,识别HCR区混入比例为11%~16%,混入比例随着分辨率下降而降低;NCR区混入比例为3%~4%,受分辨率尺度影响不大;SCR区识别比例为74%~86%,识别精度较高,识别结果与冬小麦空间分布结果保持一致。[结论]PGCM方法能够自动、便捷地确定阈值,摆脱人工判定的主观性,有效地划分出HCR、SCR和NCR 3个区域,为进一步HCR、SCR区内的作物识别提供基础。