基于像素级估计的视频显著性检测

为了减少背景噪声干扰,准确地从复杂视频中提取显著目标,提出一种具有时空一致性的视频显著区域检测算法。将视频帧划分为超像素,以超像素为基本单元提取光流特征,在时空一致性原则指导下动态融合颜色、边界信息和光流特征,获取视频显著图。在此基础上,借助视频帧的细节和区域特征对视频显著图进行细化增强。实验结果表明,算法的准确率[CD*2]召回率曲线在复杂图像数据库中高于传统经典算法,具有足够高的鲁棒性,能够减少相机运动和背景运动以及突变情况对跟踪检测的影响。所提方法能够在各种运动模式下和外观复杂场景中较为完整地提取显著目标,可作为预处理技术,改善目标跟踪、行为检测、视频压缩等的性能。     

Do investors actually value sustainability? New evidence from investor reactions to the Dow Jones Sustainability Index (DJSI)

Research Summary: Research exploring investor reactions to sustainability has substantial empirical limitations, which we address with a large‐scale longitudinal financial event study of the first global sustainability index, DJSI World. We examine investor reactions to firms from 27 countries over 17 years that are added, deleted, or continue on the index. We find that once relevant controls and comparisons to observationally equivalent firms beyond the index are included, DJSI events have only limited significance and/or materiality. Nonetheless, investors' valuation of sustainability around the world has evolved over time, involving diminishing reactions to U.S. firms and increasing benefits, particularly of continuation on the index, over time. The study highlights the importance of careful analysis and longitudinal global samples in making inferences about the financial effects of social performance. Managerial Summary: The debate about how investors perceive corporate social responsibility (CSR) predates Milton Friedman's famous statement that the only social responsibility of business is to increase profits. Although extensive research has studied whether sustainability contributes to financial performance, we have yet to understand whether investors believe it pays off. This financial event study of reactions to the addition, continuation, and deletion from DJSI World, the first global sustainability index, shows that investors care little about DJSI announcements. Nonetheless, there is some evidence that global assessments of sustainability are converging and that investors may increasingly be valuing continuation on the DJSI, suggesting that firms may gain at least limited benefits from reliable sustainability activities.     

The differential effects of CEO narcissism and hubris on corporate social responsibility

Research Summary: While prior studies have predominantly shown that CEO narcissism and hubris exhibit similar effects on various strategic decisions and outcomes, this study aims to explore the mechanisms underlying how narcissistic versus hubristic CEOs affect their firms differently. Specifically, we investigate how peer influence moderates the CEO narcissism/hubris—corporate social responsibility (CSR). With a sample of S&P 1500 firms for 2003–2010, we find that the positive relationship between CEO narcissism and CSR is strengthened (weakened) when board‐interlocked peer firms invest less (more) intensively in CSR than a CEO's own firm; the negative relationship between CEO hubris and CSR is strengthened when peer firms are engaged in less CSR than a CEO's own firm. Managerial Summary: Some CEOs are more narcissistic while others may be more hubristic, but these two groups of CEOs hold different attitudes toward the extent to which their firms should engage in corporate social responsibility (CSR). Our findings with a large sample of U.S. publically listed firms suggest that narcissistic CEOs care more about CSR, but hubristic CEOs care less. Interestingly, when narcissistic CEOs observe their peer firms engaging in more or less CSR than their own firms, they tend to respond in an opposite manner; in contrast, hubristic CEOs will only engage in even less CSR when their peers also do not emphasize CSR. Our findings point to a fundamental difference between CEO narcissism and hubris in terms of how they affect firms' CSR decisions based on their social comparison with peer firms.     

Cognitive flexibility and adaptive decision‐making: Evidence from a laboratory study of expert decision makers

Research Summary : How can strategic decision makers overcome inertia when dealing with change? In this article we argue that cognitive flexibility (i.e., the ability to match the type of cognitive processing with the type of problem at hand) enables decision makers to achieve significantly higher decision‐making performance. We show that superior decision‐making performance is associated with using semiautomatic Type 1 cognitive processes when faced with well‐structured problems, and more deliberative Type 2 processes when faced with ill‐structured problems. Our findings shed light on the individual‐level mechanism behind organizational adaptation and complement recent work on strategic inertia. In addition, our findings extend management studies that have stressed the relevance of cognitive flexibility for responding to the demands of increasingly open, flexible, and rapidly changing organizations. Managerial Summary : Humans are creatures of habits. We tend to prefer known courses of action over new ones. In many cases, habits are good. However, when things change in unpredictable ways, the past may not be good guidance for the future. We argue that “cognitive flexibility”—the ability of understanding when to rely on habits vs. when to explore new courses of action—enables managers to switch from a “fast” decision mode, based on habits, to a “slow,” more deliberate decision mode that facilitates the exploration of new courses of action. Managers high in cognitive flexibility reflect on the situation at hand, recognize and value diversity in viewpoints, and integrate such diversity in their own decision processes. By valuing diversity, they are more likely to overcome inertia.     

CEO career horizon,corporate governance,and real options: The role of economic short‐termism

Research Summary: Combining studies on real options theory and economic short‐termism, we propose that, depending on CEOs’ career horizons, CEOs have heterogeneous interests in strategic flexibility, and thus, have different incentives to make real options investments. We argue that compared to CEOs with longer career horizons, CEOs with shorter career horizons will be less inclined to make real options investments because they may not fully reap the rewards during their tenure. In addition, we argue that long‐term incentives and institutional ownership will mitigate the relationship between CEOs’ career horizons and real options investments. U.S. public firms as an empirical setting produced consistent evidence for our predictions. Our study is the first to theoretically explain and empirically show that a CEO's self‐seeking behavior will impact real options investments. Managerial Summary: This article helps to explain how a CEO's self seeking‐behavior may shape a firm's real option investment, which could result in different level of strategic flexibility. We argue that CEOs with short career horizons have less time to exercise their firms’ real options, which should lower the investments in the firms’ real options portfolios relative to CEOs with long career horizons. We study a sample of U.S. public firms and find strong evidence that a CEO's expected tenure in the firm is positively related to the real options investments at the firm level. We find that this agency issue can be mitigated by adopting appropriate corporate governance mechanisms such as long‐term incentives and institutional investors.     

Competing with complementors: An empirical look at Amazon.com

Research Summary : Platform owners sometimes enter complementors' product spaces and compete against them. Using data from Amazon.com to study Amazon's entry pattern into third‐party sellers' product spaces, we find that Amazon is more likely to target successful product spaces. We also find that Amazon is less likely to enter product spaces that require greater seller efforts to grow, suggesting that complementors' platform‐specific investments influence platform owners' entry decisions. While Amazon's entry discourages affected third‐party sellers from subsequently pursuing growth on the platform, it increases product demand and reduces shipping costs for consumers. We consider the implications of these findings for complementors in platform‐based markets. Managerial Summary : Platform owners can exert considerable influence over their complementors' welfare. Many complementors with successful products are pushed out of markets because platform owners enter their product spaces and compete directly with them. To mitigate such risks, complementors could build their businesses by aggregating nonblockbuster products or focusing on products requiring significant platform‐specific investments to grow. They should also develop capabilities in new product discovery so that they could continually bring innovative products to their platforms.     

Flexibility in the gig economy: managing time on three online piecework platforms

Gig economy platforms seem to provide extreme temporal flexibility to workers, giving them full control over how to spend each hour and minute of the day. What constraints do workers face when attempting to exercise this flexibility? We use 30 worker interviews and other data to compare three online piecework platforms with different histories and worker demographics: Mechanical Turk, MobileWorks, and CloudFactory. We find that structural constraints (availability of work and degree of worker dependence on the work) as well as cultural‐cognitive constraints (procrastination and presenteeism) limit worker control over scheduling in practice. The severity of these constraints varies significantly between platforms, the formally freest platform presenting the greatest structural and cultural‐cognitive constraints. We also find that workers have developed informal practices, tools, and communities to address these constraints. We conclude that focusing on outcomes rather than on worker control is a more fruitful way to assess flexible working arrangements.     

基于主成分分析的我国房地产业周期波动研究

运用主成分分析法构造房地产业景气综合指标（主成分）,第一主成分贡献率为0．96829,说明它保留了原始变量96．829％的信息,在房地产业周期波动分析中就可以把其他主成分舍弃。第一主成分与原始变量的相关系数p称为因子负荷量为0．70632,表明第一主成分反映了商品房销售额指标70．632％的信息。选择商品房销售额指标作为代表,来研究房地产业周期变动的特征和规律性是可行的。运用时间序列加法模型和乘法模型分析了我国房地产业周期波动的特征和规律性,我国房地产业循环波动的周期为12-13年。     

Do VCs matter? the importance of owners on performance variance in start‐up firms

Adding to the corporate effect literature, we study the effect of owners on firm performance in a new context, that of venture capital firms (VCs) and the start‐up firms in which they invest. After discussing the effect that VC ownership can have on start‐ups, we estimate that start‐up‐specific, owner (VC), and year effects account for significant variance in performance (26.3 percent, 11.2 percent and 3.7 percent, respectively). The effects of industry and investment stage are not statistically different from zero. We also provide an analysis that separates the owner effect into two components: a selection component—which impacts investment—and a management component—which explains significant variance in performance. By examining the owner effect in a different institutionalized form of governance—that of the start‐up and its relationship to VC owners—our study also contributes to an understanding of the ‘ownership’ effect in the strategy literature more generally. Copyright © 2008 John Wiley & Sons, Ltd.