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: "ultrascale simulations of non smooth granular dynamics"
  Abstract: This article presents new algorithms for massively parallel granular dynamics simulations on distributed memory architectures using a domain partitioning approach. Collisions are modelled with hard contacts in order to hide their micro-dynamics and thus to extend the time and length scales that can be simulated. The multi-contact problem is solved using a non-linear block Gauss-Seidel method that is conforming to the subdomain structure. The parallel algorithms employ a sophisticated protocol between processors that delegate algorithmic tasks such as contact treatment and position integration uniquely and robustly to the processors. Communication overhead is minimized through aggressive message aggregation, leading to excellent strong and weak scaling. The robustness and scalability is assessed on three clusters including two peta-scale supercomputers with up to 458752 processor cores. The simulations can reach unprecedented resolution of up to ten billion non-spherical particles and contacts.

Connected through hyperedge HE-1 (induced by source paper "walberla a block structured high performance framework for multiphysics simulations"):
  with members:
    - "a modular and extensible software architecture for particle dynamics"
    - "lattice boltzmann benchmark kernels as a testbed for performance analysis"
    - "extreme scale block structured adaptive mesh refinement"
    - "dynamic load balancing techniques for particulate flow simulations"
    - "the maximum dissipation principle in rigid body dynamics with inelastic impacts"
    - "a local parallel communication algorithm for polydisperse rigid body dynamics"
    - "a comparative study of fluid particle coupling methods for fully resolved lattice boltzmann simulations"
    - "a scalable and extensible checkpointing scheme for massively parallel simulations"

Connected through hyperedge HE-2 (induced by source paper "a modular and extensible software architecture for particle dynamics"):
  with members:
    - "extreme scale block structured adaptive mesh refinement"
    - "dynamic load balancing techniques for particulate flow simulations"
    - "a local parallel communication algorithm for polydisperse rigid body dynamics"
    - "a domain specific language for performance portable molecular dynamics algorithms"
    - "massively parallel algorithms for the lattice boltzmann method on nonuniform grids"

Connected through hyperedge HE-3 (induced by source paper "dynamic load balancing techniques for particulate flow simulations"):
  with members:
    - "lattice boltzmann benchmark kernels as a testbed for performance analysis"
    - "extreme scale block structured adaptive mesh refinement"
    - "a comparative study of fluid particle coupling methods for fully resolved lattice boltzmann simulations"
    - "kerncraft a tool for analytic performance modeling of loop kernels"
    - "massively parallel algorithms for the lattice boltzmann method on nonuniform grids"
    - "recent advances in graph partitioning"
    - "likwid a lightweight performance oriented tool suite for x86 multicore environments"
    - "likwid a lightweight performance oriented tool suite for x86 multicore environments"

Connected through hyperedge HE-4 (induced by source paper "a systematic comparison of dynamic load balancing algorithms for massively parallel rigid particle dynamics"):
  with members:
    - "extreme scale block structured adaptive mesh refinement"
    - "the maximum dissipation principle in rigid body dynamics with inelastic impacts"
    - "a local parallel communication algorithm for polydisperse rigid body dynamics"
    - "massively parallel algorithms for the lattice boltzmann method on nonuniform grids"

Connected through hyperedge HE-5 (induced by source paper "extreme scale block structured adaptive mesh refinement"):
  with members:
    - "massively parallel algorithms for the lattice boltzmann method on nonuniform grids"
    - "extensible component based architecture for flash a massively parallel multiphysics simulation code"

Connected through hyperedge HE-6 (induced by source paper "a local parallel communication algorithm for polydisperse rigid body dynamics"):
  with members:
    - "massively parallel algorithms for the lattice boltzmann method on nonuniform grids"
    - "computational molecular engineering as an emerging technology in process engineering"

Connected through hyperedge HE-7 (induced by source paper "a scalable and extensible checkpointing scheme for massively parallel simulations"):
  with members:
    - "a coupled lattice boltzmann method and discrete element method for discrete particle simulations of particulate flows"
    - "massively parallel algorithms for the lattice boltzmann method on nonuniform grids"
    - "a python extension for the massively parallel multiphysics simulation framework walberla"
    - "two computational models for simulating the tumbling motion of elongated particles in fluids"
    - "parallel multiphysics simulations of charged particles in microfluidic flows"
    - "a survey of fault tolerance and fault recovery techniques in parallel systems"

Connected through hyperedge HE-8 (induced by source paper "coupled multiphysics simulations of charged particle electrophoresis for massively parallel supercomputers"):
  with members:
    - "a comparative study of fluid particle coupling methods for fully resolved lattice boltzmann simulations"
    - "massively parallel algorithms for the lattice boltzmann method on nonuniform grids"
    - "two computational models for simulating the tumbling motion of elongated particles in fluids"

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.CE(Computational Engineering, Finance, and Science)