On the Subject of the Japanese Middle and Tough Constructions

“On the Subject of the Japanese Middle and Tough Constructions”. Current Issues in Unity and Diversity of Languages: Collection of the Papers Selected from the CIL 18. Seoul, KR, 2008-07-21/26, International Congress of Linguists. Korea University in Seoul, The Linguistic Society of Korea, 2009, p. 1875-1886.ArticleCurrent Issues in Unity and Diversity of Languages: Collection of the Papers Selected from the CIL 18conference pape

On the Relationship between Nominative Objects and Major Subjects in Japanese

ArticleLanguage & Information Society. 10:121-145 (2009)departmental bulletin pape

The Licensing of Nominative Case in Japanese: Evidence from Ga/No Conversion

The 8th Seoul International Conference On Generative GrammarSookmyung Women's University, SeoulAugust 9-12, 2006ArticleProceedings of the 8th Seoul International Conference on Generative Grammar : 197-212(2006)conference pape

Discovery of a wandering radio jet base after a large X-ray flare in the blazar Markarian 421

We investigate the location of the radio jet bases ("radio cores") of blazars in radio images, and their stationarity by means of dense very long baseline interferometry (VLBI) observations. In order to measure the position of a radio core, we conducted 12 epoch astrometric observation of the blazar Markarian 421 with the VLBI Exploration of Radio Astrometry at 22 GHz immediately after a large X-ray flare, which occurred in the middle of 2011 September. For the first time, we find that the radio core is not stationary but rather changes its location toward 0.5 mas downstream. This angular scale corresponds to the de-projected length of a scale of $10^5$ Schwarzschild radii (Rs) at the distance of Markarian~421. This radio-core wandering may be a new type of manifestation associated with the phenomena of large X-ray flares.Comment: 6 pages, 4 figures, 1 table, has been published in ApJ Letter

Key Science Observations of AGNs with KaVA Array

KaVA (KVN and VERA Array) is a new combined VLBI array with KVN (Korean VLBI Network) and VERA (VLBI Exploration of Radio Astrometry). First, we briefly review the imaging capabilities of KaVA array which actually achieves more than three times better dynamic range than that achieved by VERA alone. The KaVA images clearly show detailed structures of extended radio jets in AGNs. Next, we represent the key science program to be led by KaVA AGN sub working group. We will conduct the monitoring observations of Sgr A* and M87 because of the largeness of their central super-massive black hole angular sizes. The main science goals of the program are (i) testing magnetically-driven-jet paradigm by mapping velocity fields of the M87 jet, and (ii) obtaining tight constraints on physical properties of radio emitting region in Sgr A*.Comment: Proceedings of the 12th European VLBI Network Symposium and Users Meeting, 7-10 October 2014, Cagliari, Ital