Affiliation: | a Department of Electrical Engineering and Computer Science, Northwestern University, 2145 Sheridan Rd., Room M324 Evanston, IL 60208, USA b Institute of Information Science, Academic Sinica, 128 Academia Rd., Section 2, Nankang, Taipei 115, Taiwan c Department of Finance and Department of Computer Science & Information Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Rd., Taipei 106, Taiwan |