@inproceedings{kim_eun_2010, title={Age invariant regime for multi-source content update in mobile opportunistic networks}, DOI={10.1109/glocom.2010.5683934}, abstractNote={In the multi-source content update scenario where each mobile node can be both a publisher and subscriber and opportunistic contacts are used for spreading out up-to-date contents, the age of contents would be the main interest in performance evaluation. We can simplify the overall age dynamics in this scenario by two parameters, which are content update rate and contact rate among mobile users. In this paper, we analyze how the age of time-evolving contents changes in publish/subscribe scenario when Poisson update and contact are assumed, and show that there exists an age-invariant regime where the average age does not depend on content update rate or contact rate. We also compare the age-invariant regime in publish/subscribe scenario with that of service provider content update case, and show a stark contact in those regimes. Then, we extend our study into existing mobility models that generate non-Poisson contacts, show that there still exists an age-invariant regime where Poisson assumptions suffice to capture the age dynamics, and specify a general rule of thumb that decides the scope of this regime. Our work that shows the existence of an age-invariant regime is in sharp contact to previous works that highlighted the impact of mobility models under single message scenario.}, booktitle={2010 ieee global telecommunications conference globecom 2010}, author={Kim, S. and Eun, D. Y.}, year={2010} }
 @article{kim_lee_eun_2010, title={Superdiffusive Behavior of Mobile Nodes and Its Impact on Routing Protocol Performance}, volume={9}, ISSN={["1558-0660"]}, DOI={10.1109/TMC.2009.124}, abstractNote={Mobility is the most important component in mobile ad hoc networks (MANETs) and delay-tolerant networks (DTNs). In this paper, we first investigate numerous GPS mobility traces of human mobile nodes and observe superdiffusive behavior in all GPS traces, which is characterized by a ¿faster-than-linear¿ growth rate of the mean square displacement (MSD) of a mobile node. We then investigate a large amount of access point (AP) based traces, and develop a theoretical framework built upon continuous time random walk (CTRW) formalism, in which one can identify the degree of diffusive behavior of mobile nodes even under possibly heavy-tailed pause time distribution, as in the case of reality. We study existing synthetic models and trace-based models in terms of the capability of producing various degrees of diffusive behavior, and use a set of Levy walk models due to its simplicity and flexibility. In addition, we show that diffusive properties make a huge impact on contact-based metrics and the performance of routing protocols in various scenarios, and that existing models such as random waypoint, random direction model, or Brownian motion lead to overly optimistic or pessimistic results when diffusive properties are not properly captured. Our work in this paper, thus, suggests that the diffusive behavior of mobile nodes should be correctly captured and taken into account for the design and comparison study of network protocols.}, number={2}, journal={IEEE TRANSACTIONS ON MOBILE COMPUTING}, author={Kim, Sungwon and Lee, Chul-Ho and Eun, Do Young}, year={2010}, month={Feb}, pages={288–304} }
 @inproceedings{kim_hurley_wu_ji_2009, title={Ideal amino acid balance for sows during gestation and lactation}, volume={87}, number={14}, booktitle={Journal of Animal Science}, author={Kim, S. W. and Hurley, W. L. and Wu, G. and Ji, F.}, year={2009}, pages={E123–132} }
 @article{kim_eun_2008, title={Impact of super-diffusive behavior on routing performance in delay tolerant networks}, ISBN={["978-1-4244-2074-2"]}, ISSN={["1550-3607"]}, DOI={10.1109/icc.2008.554}, abstractNote={Motivated by the recent findings of super-diffusive patterns in mobility traces, we investigate the impact of super- diffusive behavior of mobile nodes on contact-based metrics and performance metrics of routing protocols in delay tolerant networks (DTNs). We show that diffusive properties make huge impact on the performance of routing protocol - message delivery ratio and delay of delivered messages, and existing models such as random waypoint models or Brownian motion models lead to overly optimistic or pessimistic results when diffusive properties are not properly captured. In addition, we point out that existing contact-based metrics are unable to differentiate between varying degrees of routing performance under different diffusive mobility patterns, and then propose to use the number of new contacts as a far more effective metric, especially for scenarios in which message routing/forwarding is built upon contacts among mobile nodes. Our work in this paper suggests that the diffusive behavior of mobile nodes should be taken into account, for the design and the performance evaluation of network protocols in DTNs.}, journal={2008 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, PROCEEDINGS, VOLS 1-13}, author={Kim, Sungwon and Eun, Do Young}, year={2008}, pages={2941–2945} }