30 research outputs found

    L’UTILISATION DU MEDIA CARTE ILLUSTREE POUR AMELIORER LA COMPETENCE DE LA COMPREHENSION ECRITE

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    Penelitian ini bertujuan untuk memaparkan media kartu bergambar sebagai media yang digunakan dalam pembelajaran membaca bahasa Perancis siswa SMA tingkat A1. Media kartu bergambar adalah media yang yang dibuat dari sebuah kertas/karton menjadi sebuah kartu berisikan gambar dan kalimat yang menujukkan gambar pada kartu tersebut. Metode penelitian yang digunakan dalam penelitian ini yaitu metode penelitian kuantitatif. Berdasarkan hasil analisis dapat disimpulkan bahwa media kartu bergambar yaitu media yang dapat membantu siswa dalam belajar membaca bahasa perancis tingkat dasar serta dapat meningkatkan kemampuan membaca siswa dan mengurangi masalah yang seringkali dihadapi seperti kosakata, struktur kalimat dan pemahaman teks/kalimat. Selanjutnya, hasil penelitian mengenai media kartu benrgambar ini, diharapkan dapat diterapkan pada pembelajaran bahasa Perancis, yaitu pada keterampilan membaca

    Competition between fluctuations and disorder in frustrated magnets

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    We investigate the effects of impurities on the nature of the phase transition in frustrated magnets, in d=4-epsilon dimensions. For sufficiently small values of the number of spin components, we find no physically relevant stable fixed point in the deep perturbative region (epsilon << 1), contrarily to what is to be expected on very general grounds. This signals the onset of important physical effects.Comment: 4 pages, 3 figures, published versio

    Frustrated magnets in three dimensions: a nonperturbative approach

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    Frustrated magnets exhibit unusual critical behaviors: they display scaling laws accompanied by nonuniversal critical exponents. This suggests that these systems generically undergo very weak first order phase transitions. Moreover, the different perturbative approaches used to investigate them are in conflict and fail to correctly reproduce their behavior. Using a nonperturbative approach we explain the mismatch between the different perturbative approaches and account for the nonuniversal scaling observed.Comment: 7 pages, 1 figure. IOP style files included. To appear in Journal of Physics: Condensed Matter. Proceedings of the conference HFM 2003, Grenoble, Franc

    Bina Keluarga Balita di Kelurahan Gedawang, Kecamatan Banyumanik

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    Kegiatan pengabdian kepada masyarakat ini telah dilaksanakan dengan baik dalam bentuk penyuluhan di kelurahan Gedawang. Kegiatan ini melibatkan tim dari Universitas PGRI Semarang dan Ibu-Ibu PKK kelurahan Gedawang. Dalam pelaksanaanya, kegiatan ini mendapatkan respon yang sangat baik. Hal ini ditandai dengan antusiasme warga/ibu-ibu PKK kelurahan Gedawang dalam mengikuti kegiatan penyuluhan. Kegiatan ini dilaksanakan pada tanggal 24 Januari 2015 dan dilanjutkan lagi pada?é?á tanggal 7 Maret 2015. Tujuan dari kegiatan ini adalah terbinanya kesadaran dan pengetahuan yang baik terhadap masalah-masalah dalam mendidik anak khususnya anak usia dini. Metode yang digunakan adalah ceramah dan tanya jawab langsung. Hasil akhir dari kegiatan IbM ini menunjukan bahwa warga/Ibu-Ibu PKK memerlukan lebih banyak informasi dan pengetahuan yang berkaitan dengan bagaimana proses mendidik anak usia dini dan bagaimana menyelesaikan masalah-masalah yang di alami oleh anak usia dini. Hal tersebut telah dibahas dengan lengkap pada penyuluhan sehingga sekarang ini warga /ibu-ibu Kelurahan Gedawang telah dapat mengurangi permasalahan yang mereka hadapi selama proses mendidik anak-anak mereka yang masih dalam usia dini

    Photonic excess noise and wave localization

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    This is a theory for the effect of localization on the super-Poissonian noise of radiation propagating through an absorbing disordered waveguide. Localization suppresses both the mean photon current I and the noise power P, but the Fano factor P/I is found to remain unaffected. For strong absorption the Fano factor has the universal value 1+3f/2 (with f the Bose-Einstein function), regardless of whether the waveguide is long or short compared to the localization length.Comment: 3 pages including 3 figure

    Conformal Anomaly and Critical Exponents of the XY-Ising Model

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    We use extensive Monte Carlo transfer matrix calculations on infinite strips of widths LL up to 30 lattice spacing and a finite-size scaling analysis to obtain critical exponents and conformal anomaly number cc for the two-dimensional XYXY-Ising model. This model is expected to describe the critical behavior of a class of systems with simultaneous U(1)U(1) and Z2Z_2 symmetries of which the fully frustrated XYXY model is a special case. The effective values obtained for cc show a significant decrease with LL at different points along the line where the transition to the ordered phase takes place in a single transition. Extrapolations based on power-law corrections give values consistent with c=3/2c=3/2 although larger values can not be ruled out. Critical exponents are obtained more accurately and are consistent with previous Monte Carlo simulations suggesting new critical behavior and with recent calculations for the frustrated XYXY model.Comment: 33 pages, 13 latex figures, uses RevTeX 3.

    Localization of Light: Dual Symmetry between Absorption and Amplification

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    We study the propagation of radiation through a disordered waveguide with a complex dielectric constant ϵ\epsilon, and show that dual systems, which differ only in the sign of the imaginary part of ϵ\epsilon, have the same localization length. Paradoxically, absorption and stimulated emission of radiation suppress the transmittance of the waveguide in the same way.Comment: Added a reference to the paper by Z.Q. Zhang, Phys.Rev.B. 52, 7960 (1995

    Statistical Signatures of Photon Localization

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    The realization that electron localization in disordered systems (Anderson localization) is ultimately a wave phenomenon has led to the suggestion that photons could be similarly localized by disorder. This conjecture attracted wide interest because the differences between photons and electrons - in their interactions, spin statistics, and methods of injection and detection - may open a new realm of optical and microwave phenomena, and allow a detailed study of the Anderson localization transition undisturbed by the Coulomb interaction. To date, claims of three-dimensional photon localization have been based on observations of the exponential decay of the electromagnetic wave as it propagates through the disordered medium. But these reports have come under close scrutiny because of the possibility that the decay observed may be due to residual absorption, and because absorption itself may suppress localization. Here we show that the extent of photon localization can be determined by a different approach - measurement of the relative size of fluctuations of certain transmission quantities. The variance of relative fluctuations accurately reflects the extent of localization, even in the presence of absorption. Using this approach, we demonstrate photon localization in both weakly and strongly scattering quasi-one-dimensional dielectric samples and in periodic metallic wire meshes containing metallic scatterers, while ruling it out in three-dimensional mixtures of aluminum spheres.Comment: 5 pages, including 4 figure

    Localization and Absorption of Light in 2D Composite Metal-Dielectric Films at the Percolation Threshold

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    We study in this paper the localization of light and the dielectric properties of thin metal-dielectric composites at the percolation threshold and around a resonant frequency where the conductivities of the two components are of the same order. In particular, the effect of the loss in metallic components are examined. To this end, such systems are modelized as random LCL-C networks, and the local field distribution as well as the effective conductivity are determined by using two different methods for comparison: an exact resolution of Kirchoff equations, and a real space renormalization group method. The latter method is found to give the general behavior of the effective conductivity but fails to determine the local field distribution. It is also found that the localization still persists for vanishing losses. This result seems to be in agreement with the anomalous absorption observed experimentally for such systems.Comment: 14 page latex, 3 ps figures. submitte

    Phase transitions in a frustrated XY model with zig-zag couplings

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    We study a new generalized version of the square-lattice frustrated XY model where unequal ferromagnetic and antiferromagnetic couplings are arranged in a zig-zag pattern. The ratio between the couplings ρ\rho can be used to tune the system, continuously, from the isotropic square-lattice to the triangular-lattice frustrated XY model. The model can be physically realized as a Josephson-junction array with two different couplings, in a magnetic field corresponding to half-flux quanta per plaquette. Mean-field approximation, Ginzburg-Landau expansion and finite-size scaling of Monte Carlo simulations are used to study the phase diagram and critical behavior. Depending on the value of ρ\rho, two separate transitions or a transition line in the universality class of the XY-Ising model, with combined Z2Z_2 and U(1) symmetries, takes place. In particular, the phase transitions of the standard square-lattice and triangular-lattice frustrated XY models correspond to two different cuts through the same transition line. Estimates of the chiral (Z2Z_2) critical exponents on this transition line deviate significantly from the pure Ising values, consistent with that along the critical line of the XY-Ising model. This suggests that a frustrated XY model or Josephson-junction array with a zig-zag coupling modulation can provide a physical realization of the XY-Ising model critical line.Comment: 11 pages, 9 figures, RevTex, to appear in Phys. Rev.
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