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: "performance study of localization techniques in wireless body area sensor networks"
  Abstract: One of the major issues in Wireless Body Area Sensor Networks (WBASNs) is efficient localization. There are various techniques for indoor and outdoor environments to locate a person. This study evaluating and compares performance of optimization schemes in indoor environments for optimal placement of wireless sensors, where patients can perform their daily activities. In indoor environments, the performance comparison between Distance Vector-Hop algorithm, Ring Overlapping Based on Comparison Received Signal Strength Indicator (ROCRSSI), Particle filtering and Kalman filtering based location tracking techniques, in terms of localization accuracy is estimated. Results show that particle filtering outperforms all. GPS and several techniques based on GSMlocation tracking schemes are proposed for outdoor environments. Hidden Markov GSM based location tracking scheme efficiently performs among all, in terms of location accuracy and computational overheads.

Connected through hyperedge HE-1 (induced by source paper "an energy efficient decoding scheme for wireless body area sensor networks"):
  with members:
    - "heer hybrid energy efficient reactive protocol for wireless sensor networks"
    - "energy efficient mac protocols in wireless body area sensor networks a survey"
    - "e horm an energy efficient hole removing mechanism in wireless sensor networks"
    - "divide and rule scheme for energy efficient routing in wireless sensor networks"
    - "density controlled divide and rule scheme for energy efficient routing in wireless sensor networks"
    - "towards lp modeling for maximizing throughput and minimizing routing delay in proactive protocols in wireless multi hop networks"
    - "srp ms a new routing protocol for delay tolerant wireless sensor networks"
    - "aid an energy efficient decoding scheme for ldpc codes in wireless body area sensor networks"

Connected through hyperedge HE-2 (induced by source paper "modeling and evaluating performance of routing operations in reactive routing protocols"):
  with members:
    - "evaluating and comparing probability of path loss in dsdv olsr and dymo at 802 11 and 802 11p"
    - "ach away cluster heads scheme for energy efficient clustering protocols in wsns"
    - "heer hybrid energy efficient reactive protocol for wireless sensor networks"
    - "evaluating wireless reactive routing protocols with linear programming model for wireless ad hoc networks"
    - "on energy efficiency and delay minimization in reactive protocols in wireless multi hop networks"
    - "e horm an energy efficient hole removing mechanism in wireless sensor networks"
    - "density controlled divide and rule scheme for energy efficient routing in wireless sensor networks"
    - "towards lp modeling for maximizing throughput and minimizing routing delay in proactive protocols in wireless multi hop networks"

Connected through hyperedge HE-3 (induced by source paper "the fame threshold based energy efficient fatigue measurement for wireless body area sensor networks using multiple sinks"):
  with members:
    - "energy efficient mac protocols in wireless body area sensor networks a survey"
    - "noise filtering channel modeling and energy utilization in wireless body area networks"
    - "adaptive reliable medium access control protocol for wireless body area networks"
    - "m attempt a new energy efficient routing protocol in wireless body area sensor networks"
    - "modeling propagation characteristics for arm motion in wireless body area sensor networks"
    - "on using multiple quality link metrics with destination sequenced distance vector protocol for wireless multi hop networks"
    - "identifying design requirements for wireless routing link metrics"
    - "interference and bandwidth adjusted etx in wireless multi hop networks"

Connected through hyperedge HE-4 (induced by source paper "aid an energy efficient decoding scheme for ldpc codes in wireless body area sensor networks"):
  with members:
    - "energy efficient mac protocols in wireless body area sensor networks a survey"
    - "e horm an energy efficient hole removing mechanism in wireless sensor networks"
    - "divide and rule scheme for energy efficient routing in wireless sensor networks"
    - "density controlled divide and rule scheme for energy efficient routing in wireless sensor networks"
    - "adaptive reliable medium access control protocol for wireless body area networks"
    - "modeling and evaluating enhancements in expanding ring search algorithm for wireless reactive protocols"
    - "energy efficiency and reliability in wireless biomedical implant systems"
    - "towards a communication theoretic understanding of system level power consumption"

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.NI(Networking and Internet Architecture)