88,701 research outputs found

    “The end justifies the means”

    Get PDF
    This paper seeks to demonstrate how the format of the current UPSR (Ujian Penilaian Sekolah Rendah) examination influences the style of teaching of English in Primary Schools from Year 1 to 6. “Teachers teach for the test” is a common expression used to justify approaches to language teaching, and as the ‘test’ has only reading and writing components, oral and listening skills are given scant recognition for any contribution in preparing for the ‘test’. It is not the place of this paper to suggest wholesale changes to the UPSR examination, but that the preparation for this final test can be made more efficient by developing the students’ skills of listening and speaking as a foundation and efficient springboard to prepare them for the reading and writing elements of the test. This paper details changes in the assessment system for primary level one only, as the final three years of the child’s teaching can be dedicated to the intense preparation for success in the examination. This preparation will be much easier and more efficient because the children will be able to build on a foundation of communicative skills, prior to embarking on the more academic skills needed for the examination. This will serve the pupils in two ways, by allowing them to be more communicative with their language skills and give them a good foundation for the grammar, reading and written exercises which are the sole features of the UPSR examination. I will also give practical examples of level 1 Primary Schools examinations which can be more communicative and still be faithful to long term UPSR preparation. Versions of this scheme are already being carried out in Kelantan and a report on this will also be presented

    Exploiting long-range disorder in slow-light photonic crystal waveguides

    Full text link
    The interplay between order and disorder in photonic lattices opens up a wide range of novel optical scattering mechanisms, resonances, and applications that can be obscured by typical ordered design approaches to photonics. Striking examples include Anderson localization, random lasers, and visible light scattering in biophotonic structures such as butterfly wings. In this work, we present a profound example of light localization in photonic crystal waveguides by introducing long-range correlated disorder. Using a rigorous three-dimensional Bloch mode expansion technique, we demonstrate how inter-hole correlations have a negative contribution to the total out-of-plane radiative losses, leading to a pronounced enhancement of the quality factor, QQ, and Q/VQ/V cavity figures of merit in the long-range correlation regime. Subsequently, the intensity fluctuations of the system are shown to globally increase with the correlation length, highlighting the non-trivial role of long-range disorder on the underlying scattering mechanisms. We also explore the possibility of creating ultra-high quality cavity modes via inter-hole correlations, which have various functionalities in chip-based nonlinear optics and waveguide cavity-quantum electrodynamics.Comment: Updated version with DO

    Far-infrared investigation of the Taurus star-forming region using the IRAS database

    Get PDF
    The Infrared Astronomical Satellite (IRAS) has given us the first completely unbiased sky-survey in the far-infrared with wavebands centered at 12, 25, 60 and 100 microns. The Taurus-Auriga complex was selected as the first molecular cloud to be investigated in this study. The Taurus clouds were defined as lying between 04h and 05h in R.A. and +16 to +31 degrees in Dec., then the IRAS point-source catalogue was searched for sources with good or moderate quality fluxes in all three of the shortest IRAS bands. The sources which were selected in this way were then classified into subgroups according to their IRAS colors. Taurus is generally believed to be an area of low-mass star formation, having no luminous O-B associations within or near to the cloud complex. Once field stars, galaxies and planetary nebulae had been removed from the sample only the molecular cloud cores, T Tauri stars and a few emission-line A and B stars remained. The great majority of these objects are pre-main sequence in nature and, as stated by Chester (1985), main sequence stars without excess far-infrared emission would only be seen in Taurus if their spectral types were earlier than about A5 and then not 25 microns. By choosing our sample in this way we are naturally selecting the hotter and thus more evolved sources. To counteract this, the molecular cloud core-criterion was applied to soruces with good or moderate quality flux at 25, 60 and 100 microns, increasing the core sample by about one third. The candidate protostar B335 is only detected by IRAS at 60 and 100 microns while Taurus is heavily contaminated by cirrus at 100 microns. This means that detection at 25 microns is also required with those at 60 and 100 microns to avoid confusing a ridge of cirrus with a genuine protostar. The far-infrared luminosity function of these sources is then calculated and converted to the visual band by a standard method to compare with the field star luminosity function of Miller and Scalo. The eventual aim of this work is to obtain far-infrared luminosity functions for a number of molecular clouds which are known to be forming low-mass stars and to investigate how the slope is affected by changes in the density and turbulence of material