Leverage, Growth Opportunities and Firm Investment: The Case of Manufacturing Firms in China

This paper examined the impact of financial leverage on investment decisions offirms using the panel data of publicly traded Chinese firms. We collected data for511 manufacturing companies during the period from 2005 to 2013 to do theresearch. The data shows that financial leverage is negatively correlated with afirm’s investment. Moreover, after we categorized the data into two types: 1)high-growth firms and 2) low-growth firms, it demonstrated that such negativecorrelation is significant for low-growth firms while insignificant for high-growthfirms. Additionally, long-term debt has a more significant negative correlation toinvestment than short-term debt

Optical Flow Guided Feature: A Fast and Robust Motion Representation for Video Action Recognition

Motion representation plays a vital role in human action recognition in videos. In this study, we introduce a novel compact motion representation for video action recognition, named Optical Flow guided Feature (OFF), which enables the network to distill temporal information through a fast and robust approach. The OFF is derived from the definition of optical flow and is orthogonal to the optical flow. The derivation also provides theoretical support for using the difference between two frames. By directly calculating pixel-wise spatiotemporal gradients of the deep feature maps, the OFF could be embedded in any existing CNN based video action recognition framework with only a slight additional cost. It enables the CNN to extract spatiotemporal information, especially the temporal information between frames simultaneously. This simple but powerful idea is validated by experimental results. The network with OFF fed only by RGB inputs achieves a competitive accuracy of 93.3% on UCF-101, which is comparable with the result obtained by two streams (RGB and optical flow), but is 15 times faster in speed. Experimental results also show that OFF is complementary to other motion modalities such as optical flow. When the proposed method is plugged into the state-of-the-art video action recognition framework, it has 96:0% and 74:2% accuracy on UCF-101 and HMDB-51 respectively. The code for this project is available at https://github.com/kevin-ssy/Optical-Flow-Guided-Feature.Comment: CVPR 2018. code available at https://github.com/kevin-ssy/Optical-Flow-Guided-Featur

Estimation of Large Network Formation Games

This paper develops estimation methods for network formation models using observed data from a single large network. The model allows for utility externalities from friends of friends and friends in common, so the expected utility is nonlinear in the link choices of an agent. We propose a novel method that uses the Legendre transform to express the expected utility as a linear function of the individual link choices. This implies that the optimal link decision is that for an agent who myopically chooses to establish links or not to the other members of the network. The dependence between the agent's link choices is through an auxiliary variable. We propose a two-step estimation procedure that requires weak assumptions on equilibrium selection, is simple to compute, and has consistent and asymptotically normal estimators for the parameters. Monte Carlo results show that the estimation procedure performs well

Party On: The Labor Market Returns to Social Networks in Adolescence

We investigate the returns to adolescent friendships on earnings in adulthood. Using data from the National Longitudinal Study of Adolescent to Adult Health, we document that individuals make investments to accumulate friends in addition to educational investments. Because both education and friendships are jointly determined in adolescence, OLS estimates of their returns are biased. To estimate the causal returns to friendships, we implement a novel procedure that assumes the returns to schooling range from 5 to 15% (as the literature has documented), and instrument for friendships using homophily (similarity) measures among peers to obtain bounds on the returns to friendships. We find that having one more friend in adolescence increases earnings between 7 and 14%, which is substantially larger than the OLS estimates: measurement error and omitted variables lead to significant downward bias

Academic procrastination precedes problematic mobile phone use in Chinese adolescents: A longitudinal mediation model of distraction cognitions

Cross-sectional studies have documented a positive association between academic procrastination and problematic mobile phone use (PMPU). However, the specific predictive direction has remained controversial and the potential mechanisms underlying the association have not been rigorously evaluated. According to Davis's cognitive-behavioral model, Brand et al.’s I-PACE model, and procrastination-related theories, academic procrastination and PMPU might have a reciprocal relationship and distraction cognitions might play a mediating role in this process. A total of 633 secondary school students completed three self-report questionnaires at three 6-month intervals over the course of 1.5 years. The cross-lagged panel model results showed that earlier academic procrastination positively predicted subsequent PMPU over time, but the reverse prediction was not stable. Furthermore, distraction cognitions played a mediating role in linking earlier academic procrastination and subsequent PMPU. These findings indicate that academic procrastination precedes PMPU with distraction cognitions as a potential mediator, which contributes to clarifying the controversial relationship and explicating the underlying mechanism. Overall, interventions for academic procrastination may be effective in reducing maladaptive cognitions associated with mobile phones and preventing adolescents from developing PMPU

The mediating and moderating roles of social anxiety and relatedness need satisfaction on the relationship between shyness and problematic mobile phone use among adolescents

Shyness has been reported to be closely associated with problematic mobile phone use, yet the underlying mechanism which may mediate or moderate this relationship remains obscure. Based on the cognitive-behavioral model of pathological internet use, combined with the theory of compensatory internet use and self-determination theory, the current study aimed to examine the association between shyness and problematic mobile phone use and the mediating role of social anxiety, as well as the moderating role of relatedness need satisfaction perceived on the mobile phone. A sample of 1050 Chinese adolescents recruited from middle schools completed the questionnaires. Mediation analysis revealed that social anxiety could partially mediate the relationship between shyness and problematic mobile phone use. Furthermore, moderated mediation analysis indicated that shyness could exacerbate problematic mobile phone use through social anxiety for adolescents with a higher level of relatedness need satisfaction from the mobile phone compared to a lower level of need satisfaction. Overall, these findings advance the understanding of how and when shyness leads to problematic mobile phone use. Implications for research on mobile phone use are discussed

Flame synthesized blue TiO₂₋ₓ with tunable oxygen vacancies from surface to grain boundary to bulk

Fabrication of nonstoichiometric metal oxides containing oxygen vacancies (OVs) has been an effective strategy to modulate their (photo)catalytic or (photo)electrochemical performances which are all affected by charge transfer at the interface and in the bulk. Considerable efforts are still needed to achieve tunability of OVs, as well as their quantitative characterization. Herein, a one-step flame synthesis method is reported for the first time for fast fabrication of blue TiO2- x with controllable defect content and location. Temperature-programmed oxidation (TPO) analysis is applied for the first time and found to be an excellent technique in both differentiating and quantifying OVs at the surface, grain boundary (GB), and bulk of TiO2- x . The results indicate that a moderate level of OVs can greatly enhance the charge transfer. Importantly, the OVs locked at GBs due to the thermal sintering of nanoparticles during the synthesis can facilitate the anchoring and reduction of Pt species.National Research Foundation (NRF)This work was financially supported by National Research Foundation through the Cambridge Centre for Carbon Reduction in Chemical Technology (C4T) CREATE Programme

Elucidating reaction pathways of the CO₂ electroreduction via tailorable tortuosities and oxidation states of Cu nanostructures

Copper-based 3D fractal nanostructures are integrated on the electrodes using a scalable and ink-free flame aerosol synthesis technique for electrochemical CO2 reduction. The effects of tortuosity and oxidation state of copper are respectively investigated by isolating each effect from the others. By balancing the intermediate confinement and local availability of CO2, CuO-derived Cu with optimal tortuosity exhibits a Faradaic efficiency of 65% toward C2+ products at an applied potential of −1.04 V versus reversible hydrogen electrode. A subsequent study of the effects of the oxidation state, which is free from the influence of tortuosity, reveals that Cu2+-derived Cu demonstrates suppressed hydrogen evolution reaction and a higher C2+/CH4 ratio than metallic Cu. The preference for the formation of both ethanol and n-propanol versus ethylene, is found to follow the trend from metallic Cu > Cu2+-derived Cu > Cu+-derived Cu toward alcohols’ formation. These findings elucidate the underlying causes for the effects of tortuosity of porous Cu electrodes on selectivity and provide insights into the specific effects of the initial oxidation state on various reaction pathways during electrochemical CO2 reduction.National Research Foundation (NRF)Submitted/Accepted versionThis work was supported by the eCO2EP and C4T2 programs funded by the Singapore National Research Foundation under its Campus for Research Excellence and Technological Enterprise (CREATE) program through the Cambridge Centre for Advanced Research and Education in Singapore (CARES) and the Berkeley Educational Alliance for Research in Singapore (BEARS)