EVEN, GENDHING DAN IMAGINASI DALAM PERTUNJUKAN GAMELAN

In performances Javanese musicians use several ways to create imagination. Among those methods they use titles of musical compositions to attract audiences’ thought. The titles, among the most common ways, are meaningful because in addition to have literal meanings they also create meanings in the context of performances. Using the titles musician “speak” to audiences like other group people communicate with other means in their community

<Book Reviews>Richard Chauvel, Nationalists, Soldiers and Separatists : The Ambonese Islands from Colonialism to Revolt 1880-1950. Leiden : KITLV Press, 1990, xv+432p.

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました

Influence of generalized focusing of few-cycle Gaussian pulses in attosecond pulse generation

In contrast to the case of quasi-monochromatic waves, a focused optical pulse in the few-cycle limit may exhibit two independent curved wavefronts, associated with phase and group retardations, respectively. Focusing optical elements will generally affect these two wavefronts differently, thus leading to very different behavior of the pulse near focus. As limiting cases, we consider an ideal diffractive lens introducing only phase retardations and a perfect non-dispersive refractive lens (or a curved mirror) introducing equal phase and group retardations. We study the resulting diffraction effects on the pulse, finding both strong deformations of the pulse shape and shifts in the spectrum. We then show how important these effects can be in highly nonlinear optics, by studying their role in attosecond pulse generation. In particular, the focusing effects are found to affect substantially the generation of isolated attosecond pulses in gases from few-cycle fundamental optical fields.Comment: 8 pages and 6 figure

Formation and Evolution of Dwarf Elliptical Galaxy(Proceedings of Japan-France Seminar on Chemical Evolution of Galaxies with Active Star Formation)

Evolution of the dwarf elliptical galaxy is considered with special attention to gas loss from the galaxy by supernova explosion. The dwarf elliptical galaxy is modeled as a spherical ensemble of gas clouds undergoing mass loss and its structural evolution is followed by N-body simulation. A significant fraction of the initial mass should have been lost from dEs. The characteristic structure of observed dEs is naturally explained if the gas is mainly ejected from the central region of the galaxy

The effect of plasma-core induced self-guiding on phase matching of high-order harmonic generation in gases

In this work we numerically study a self-guiding process in which ionization plays a dominant role and analyze its effect on high-order harmonic generation (HHG) in gases. Although this type of self-guiding --- termed as plasma-core induced self-guiding in previous works --- limits the achievable cut-off by regulating the intensity of the laser beam, it provides favorable conditions for phase matching, which is indispensable for high-flux gas high-harmonic sources. To underline the role of self-guiding in efficient HHG, we investigate the time-dependent phase matching conditions in the guided beam and show how the spatio-temporally constant fundamental intensity contributes to the constructive build-up of the harmonic field in a broad photon-energy range up to the provided cut-off.Comment: 14 pages, 7 figure

Star Formation Timescales and the Schmidt Law

We offer a simple parameterization of the rate of star formation in galaxies. In this new approach, we make explicit and decouple the timescales associated (a) with disruptive effects the star formation event itself, from (b) the timescales associated with the cloud assembly and collapse mechanisms leading up to star formation. The star formation law in near-by galaxies, as measured on sub-kiloparsec scales, has recently been shown by Bigiel et al. to be distinctly non-linear in its dependence on total gas density. Our parameterization of the spatially resolved Schmidt-Sanduleak relation naturally accommodates that dependence. The parameterized form of the relation is rho_* ~ epsilon x rho_g/(tau_s + rho_g ^{-n}), where rho_g is the gas density, epsilon is the efficiency of converting gas into stars, and rho_g^{-n} captures the physics of cloud collapse. Accordingly at high gas densities quiescent star formation is predicted to progress as rho_* ~ rho_g, while at low gas densities rho_* ~ rho_g^{1+n}, as is now generally observed. A variable efficiency in locally converting gas into stars as well as the unknown plane thickness variations from galaxy to galaxy, and radially within a given galaxy, can readily account for the empirical scatter in the observed (surface density rather than volume density) relations, and also plausibly account for the noted upturn in the relation at very high apparent projected column densities.Comment: Accepted to the Astrophysical Joirnal (Letters); 10 pages, 1 figure; Revised caption is now fully readable. One reference correcte