Learning multi-robot coordination from demonstrations

This paper develops a Distributed Differentiable Dynamic Game (DDDG) framework, which enables learning multi-robot coordination from demonstrations. We represent multi-robot coordination as a dynamic game, where the behavior of a robot is dictated by its own dynamics and objective that also depends on others' behavior. The coordination thus can be adapted by tuning the objective and dynamics of each robot. The proposed DDDG enables each robot to automatically tune its individual dynamics and objectives in a distributed manner by minimizing the mismatch between its trajectory and demonstrations. This process requires a new distributed design of the forward-pass, where all robots collaboratively seek Nash equilibrium behavior, and a backward-pass, where gradients are propagated via the communication graph. We test the DDDG in simulation with a team of quadrotors given different task configurations. The results demonstrate the capability of DDDG for learning multi-robot coordination from demonstrationsComment: 6 figure

Clinical effect of neovascular glaucoma treated by vitrectomy and cyclophotocoagulation

AIM: To observe the postoperative intraocular pressure(IOP)and operation safety in the eyes of the neovascular glaucoma pateints treated by intraocular cyclophotocoagulation which needed vitrectomy at the same time. <p>METHODS: A total of 12 neovascular glaucoma cases(14 eyes)secondary to diabetic retinopathy, retinal detachment surgery and trauma were reviewed in our study. This procedure mainly used intraocular photocoagulation catheter to highlight the ciliary processes until the ciliary became white atrophy or plosion after vitreous surgery treatment. The intraocular photocoagulation catheter was performed at a power of 300-500mW, for a duration of 0.1-0.2ms. Postoperative follow-up was at least for 6mo. The observation of 14 postoperative neovascular glaucoma was performed at 1wk, 1, 6mo observing the IOP and complications. <p>RESULTS: IOP of the 11 eyes was significantly declined and controlled in normal. After cyclophotocoagulation, average IOP at 1wk was 16.7±14.4mmHg, 15.7±8.8mmHg at 1mo and 12.9±4.5mmHg at 6mo, which compared with untreatment(39.6 ±10.0mmHg)was statistically significant different(<i>P</i><0.01). In follow up time 3 cases were relapsed which were supplied with transscleral or endoscope cyclophotocoagulation. During the follow-up period no endophthalmitis and complications such as eyeball atrophy were found. <p>CONCLUSION: The intraocular cyclophotocoagulation and vitrectomy simultaneously can deal with the primary disease and secondary neovascular glaucoma. The operation can be accurately performed under direct cyclophotocoagulation and it is a safe and effective way for neovascular glaucoma which needs vitreous surgery

Zeros of solutions of certain second order linear differential equation

AbstractIn this paper, we investigate the exponent of convergence of the zero-sequence of solutions of the differential equation(1.3)f″+(Q1eP1(z)+Q2eP2(z)+Q3eP3(z))f=0, where P1(z), P2(z), P3(z) are polynomials of degree n⩾1, Q1, Q2, Q3 are entire functions of order less than n