Browsing by Author "Song, Yan"

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    A numerical model to calculated field line resonances in Jupiter's magnetosphere
    (2020-08-07) Lysak, Robert L; Song, Yan; lysak001@umn.edu; Lysak, Robert L; Minnesota Institute for Astrophysics
    The arrival of the Juno satellite at Jupiter has led to an increased interest in the dynamics of the Jovian magnetosphere. Jupiter’s auroral emissions often exhibit quasi-periodic oscillations with periods of tens of minutes. Magnetic observations indicate that ultra-low-frequency (ULF) waves with similar periods are often seen in data from Galileo and other satellites traversing the Jovian magnetosphere. Such waves can be associated with field line resonances, which are standing shear Alfvén waves on the field lines. Using model magnetic fields and plasma distributions, the frequencies of field line resonances and their harmonics on field lines connecting to the main auroral oval have been determined. Time domain simulations of Alfvén wave propagation have illustrated the evolution of such resonances. These studies indicate that harmonics of the field line resonances are common in the 10-40 minute band.
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    The Role of Employment Subcenters in Residential Location Decisions
    (Journal of Transport and Land Use, 2008) Cho, Eun Joo; Rodriguez, Daniel A.; Song, Yan
    In this paper we employ Mecklenburg County, North Carolina, a polycentric city with 10 employment subcenters, as a case study to explore the role of employment subcenters in determining residential location decisions. We estimate discrete choice models of residential location decisions: conditional logit models and heteroscedastic logit models with both the full choice set and sampled choices. We find that access to certain employment subcenters, measured in terms of generalized cost, is an important determinant of households’ residential location decisions. The proximity to specific employment subcenters varies across households with different income levels. These patterns can be explained by existing land use and transportation patterns, as well as by subcenters’ economic specialization.