human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "an efficiently solvable quadratic program for stabilizing dynamic locomotion"
  Abstract: We describe a whole-body dynamic walking controller implemented as a convex quadratic program. The controller solves an optimal control problem using an approximate value function derived from a simple walking model while respecting the dynamic, input, and contact constraints of the full robot dynamics. By exploiting sparsity and temporal structure in the optimization with a custom active-set algorithm, we surpass the performance of the best available off-the-shelf solvers and achieve 1kHz control rates for a 34-DOF humanoid. We describe applications to balancing and walking tasks using the simulated Atlas robot in the DARPA Virtual Robotics Challenge.

Connected through hyperedge HE-1 (induced by source paper "an inverse dynamics approach to control lyapunov functions"):
  with members:
    - "dynamic walking with compliance on a cassie bipedal robot"
    - "momentum control with hierarchical inverse dynamics on a torque controlled humanoid"
    - "torque saturation in bipedal robotic walking through control lyapunov function based quadratic programs"

Connected through hyperedge HE-2 (induced by source paper "passive whole body control for quadruped robots experimental validation over challenging terrain"):
  with members:
    - "heuristic planning for rough terrain locomotion in presence of external disturbances and variable perception quality"
    - "simultaneous contact gait and motion planning for robust multi legged locomotion via mixed integer convex optimization"
    - "motion planning for quadrupedal locomotion coupled planning terrain mapping and whole body control"
    - "real time motion planning of legged robots a model predictive control approach"
    - "momentum control with hierarchical inverse dynamics on a torque controlled humanoid"

Connected through hyperedge HE-3 (induced by source paper "feedback control of an exoskeleton for paraplegics toward robustly stable hands free dynamic walking"):
  with members:
    - "torque saturation in bipedal robotic walking through control lyapunov function based quadratic programs"

Connected through hyperedge HE-4 (induced by source paper "walking stabilization using step timing and location adjustment on the humanoid robot atlas"):
  with members:
    - "walking on partial footholds including line contacts with the humanoid robot atlas"
    - "step timing adjustment a step toward generating robust gaits"

Connected through hyperedge HE-5 (induced by source paper "automatic gain tuning of a momentum based balancing controller for humanoid robots"):
  with members:
    - "automatic lqr tuning based on gaussian process global optimization"
    - "balancing experiments on a torque controlled humanoid with hierarchical inverse dynamics"

Connected through hyperedge HE-6 (induced by source paper "momentum control with hierarchical inverse dynamics on a torque controlled humanoid"):
  with members:
    - "state estimation for a humanoid robot"
    - "balancing experiments on a torque controlled humanoid with hierarchical inverse dynamics"

Connected through hyperedge HE-7 (induced by source paper "learning model predictive control for iterative tasks a data driven control framework"):
  with members:
    - "autonomous racing using learning model predictive control"
    - "incremental sampling based algorithms for optimal motion planning"

Connected through hyperedge HE-8 (induced by source paper "a new time projecting controller based on 3lp model to recover intermittent pushes"):
  with members:
    - "3lp a linear 3d walking model including torso and swing dynamics"
    - "real time planning with primitives for dynamic walking over uneven terrain"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.RO(Robotics)