A User Interface Using a Spiral Representation for Image Retrieval on a Mobile Terminal

10th asia pacific conference on Computer human interaction (APCHI '12), August 28-31, 2012 in Matsue-city, Shimane, Japan.To efficiently visualize a set of images for a similar image search system on a mobile terminal which is equipped with a touch screen, we propose a method that ranked images are represented in a spiral manner and they can be dragged along the spiral for finding a target image. We also propose efficient search operations for the system. As a result of comparison experiments between our system and a traditional one, evaluations of our system in terms of 'intuitive', 'beauty', 'fun', and 'novelty' were higher than those of traditional one.ArticleProceedings of the 10th asia pacific conference on Computer human interaction. :625-626 (2012)conference pape

Local SiC photoluminescence evidence of non-mutualistic hot spot formation and sub-THz coherent emission from a rectangular Bi2_2Sr2_2CaCu2_2O8+δ_{8+\delta} mesa

From the photoluminescence of SiC microcrystals uniformly covering a rectangular mesa of the high transition temperature $T_c$ superconductor Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$, the local surface temperature $T({\bm r})$ was directly measured during simultaneous sub-THz emission from the $N\sim10^3$ intrinsic Josephson junctions (IJJs) in the mesa. At high bias currents $I$ and low bath temperatures $T_{\rm bath}\lesssim~35$ K, the center of a large elliptical hot spot with $T({\bm r})> T_c$ jumps dramatically with little current-voltage characteristic changes. The hot spot doesn't alter the ubiquitous primary and secondary emission conditions: the ac Josephson relation and the electromagnetic cavity resonance excitation, respectively. Since the intense sub-THz emission was observed for high $T_{\rm bath}\gtrsim~50$ K in the low $I$ bias regime where hot spots are absent, hot spots can not provide the primary mechanisms for increasing the output power, the tunability, or for promoting the synchronization of the $N$ IJJs for the sub-THz emission, but can at best coexist non-mutualistically with the emission. No $T({\bm r})$ standing waves were observed