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A densely distributed network radar system compensates for the disadvantages of sparse radars and poses a significant threat to low-altitude penetration by an unmanned combat aerial vehicle (UCAV). Unlike previous studies, this paper aims to consider radar blind areas and proposes a rapid online method for planning low-altitude penetration paths.

First, the optimization problem coupling digital elevation map (DEM), radar detection probability model and nonholonomic UCAV kinematic model is established. Second, an online solution framework of penetration path planning is constructed. An intervisibility method and map scaling are proposed to generate a detection probability map (DPM). Through completeness and consistency analysis, an adaptive hybrid A* algorithm with fast local replanning strategy is proposed to search a path that takes into account time-consuming, detection probability under nonholonomic constraints. Finally, three scenarios of multiple known, pop-up and vanished static radars are simulated using C++. The computational performance is compared and analyzed.

The results showed that the proposed online method can generate low-detection-probability penetration paths within subseconds.

This paper provides a new online method to plan UCAV penetration trajectory in military and academic contexts.

This paper aims to investigate whether single-name options trading prior to earnings announcements is more informative when there exist real activity manipulations.

Using 5,419 earnings announcements during 2004–2018 made by 208 public US companies with relatively high options volumes ranked by the CBOE, the authors uncover two regularities using predictive regressions for stock return.

First, the total options volume up to twenty days pre-announcement is significantly higher than that in other periods only for earnings management firms; moreover, after detailing options characteristics, the authors find these intensive pre-announcement trading to be concentrated in transactions of in-the-money call and long-term maturity put options. Second, an increase in the single-name call minus put options volume can positively predict the underlying stock’s next-day excess return much better in real earnings management firms, with a larger magnitude of effect in periods right before regular earnings announcement dates.

This paper makes a marginal and novel contribution by showing that real earnings management can serve as a proxy for the potential profit from informed trading in options as the return predictability of options volume becomes stronger for firms that have the manipulation motive and indeed perform manipulative actions.