A Semicoarsening Multigrid Algorithm for SIMD Machines

A semicoarsening multigrid algorithm suitable for use on single instruction multiple data (SIMD) architectures has been implemented on the CM-2. The method performs well for strongly anisotropic problems and for problems with coefficients jumping by orders of magnitude across internal interfaces. The parallel efficiency of this method is analyzed, and its actual performance is compared with its performance on some other machines, both parallel and nonparallel

Investigation of transition frequencies of two acoustically coupled bubbles using a direct numerical simulation technique

The theoretical results regarding the ``transition frequencies'' of two acoustically interacting bubbles have been verified numerically. The theory provided by Ida [Phys. Lett. A 297 (2002) 210] predicted the existence of three transition frequencies per bubble, each of which has the phase difference of $\pi /2$ between a bubble's pulsation and the external sound field, while previous theories predicted only two natural frequencies which cause such phase shifts. Namely, two of the three transition frequencies correspond to the natural frequencies, while the remaining does not. In a subsequent paper [M. Ida, Phys. Rev. E 67 (2003) 056617], it was shown theoretically that transition frequencies other than the natural frequencies may cause the sign reversal of the secondary Bjerknes force acting between pulsating bubbles. In the present study, we employ a direct numerical simulation technique that uses the compressible Navier-Stokes equations with a surface-tension term as the governing equations to investigate the transition frequencies of two coupled bubbles by observing their pulsation amplitudes and directions of translational motion, both of which change as the driving frequency changes. The numerical results reproduce the recent theoretical predictions, validating the existence of the transition frequencies not corresponding to the natural frequency.Comment: 18 pages, 8 figures, in pres

Brane Cosmology With Generalized Chaplygin Gas in The Bulk

We find exact solution of the Einstein equations in the context of the brane world scenario. We have supposed a {generalized chaplygin gas} equation of state for bulk. This study display a constant energy density and pressure for bulk in late time. It is shown that our assumptions impose a specific equation of state on brane. {In this work, we have obtained a decelerate universe in early time and late time.} In the end, it is shown that under some assumption we have equation of state of cosmological constant for bulk.Comment: 11 page

Planetesimal disk evolution driven by embryo-planetesimal gravitational scattering

The process of gravitational scattering of planetesimals by a massive protoplanetary embryo is explored theoretically. We propose a method to describe the evolution of the disk surface density, eccentricity, and inclination caused by the embryo-planetesimal interaction. It relies on the analytical treatment of the scattering in two extreme regimes of the planetesimal epicyclic velocities: shear-dominated (dynamically ``cold'') and dispersion-dominated (dynamically ``hot''). In the former, planetesimal scattering can be treated as a deterministic process. In the latter, scattering is mostly weak because of the large relative velocities of interacting bodies. This allows one to use the Fokker-Planck approximation and the two-body approximation to explore the disk evolution. We compare the results obtained by this method with the outcomes of the direct numerical integrations of planetesimal orbits and they agree quite well. In the intermediate velocity regime an approximate treatment of the disk evolution is proposed based on interpolation between the two extreme regimes. We also calculate the rate of embryo's mass growth in an inhomogeneous planetesimal disk and demonstrate that it is in agreement with both the simulations and earlier calculations. Finally we discuss the question of the direction of the embryo-planetesimal interaction in the dispersion-dominated regime and demonstrate that it is repulsive. This means that the embryo always forms a gap in the disk around it, which is in contrast with the results of other authors. The machinery developed here will be applied to realistic protoplanetary systems in future papers.Comment: 40 pages, 9 figures, submitted to A

Unconventional cosmology on the (thick) brane

We consider the cosmology of a thick codimension 1 brane. We obtain the matching conditions leading to the cosmological evolution equations and show that when one includes matter with a pressure component along the extra dimension in the brane energy-momentum tensor, the cosmology is of non-standard type. In particular one can get acceleration when a dust of non-relativistic matter particles is the only source for the (modified) Friedman equation. Our equations would seem to violate the conservation of energy-momentum from a 4D perspective, but in 5D the energy-momentum is conserved. One could write down an effective conserved 4D energy-momentum tensor attaching a ``dark energy'' component to the energy-momentum tensor of matter that has pressure along the extra dimension. This extra component could, on a cosmological scale, be interpreted as matter-coupled quintessence. We comment on the effective 4D description of this effect in terms of the time evolution of a scalar field (the 5D radion) coupled to this kind of matter.Comment: 9 pages, v2. eq.(17) corrected, comments on effective theory change

Pengaruh Implementasi Pendekatan Saintifik Terhadap Sikap Sosial Dan Hasil Belajar Pkn Di Kelas VI SD Jembatan Budaya, Kuta

Penelitian ini bertujuan untuk mengetahui pengaruh pendekatan saintifik terhadap sikap sosial dan hasil belajar PKn di kelas VI SD Jembatan Budaya, Kuta. Populasi dalam penelitian ini 91 orang siswa. Sedangkan sampel penelitiannya sebanyak 46 orang siswa. Data sikap sosial dikumpulkan dengan metode kuesioner dan data hasil belajar PKn dikumpulkan dengan tes objektif. Analisis data yang digunakan dalam penelitian ini adalah MANOVA. Rancangan penelitian ini menggunakan Posttest Only Control Group Design. Berdasarkan penelitian yang telah dilakukan didapatkan hasil bahwa: 1) terdapat perbedaan sikap sosial antara siswa yang mengikuti pembelajaran dengan pendekatan saintifik dengan siswa yang mengikuti model pembelajaran konvensional, 2) terdapat perbedaan hasil belajar PKn antara siswa yang mengikuti pembelajaran dengan pendekatan saintifik dengan siswa yang mengikuti model pembelajaran konvensional, 3) secara simultan, terdapat perbedaan sikap sosial dan hasil belajar PKn antara siswa yang mengikuti pembelajaran dengan pendekatan saintifik dengan siswa yang mengikuti model pembelajaran konvensional.Kata Kunci : hasil belajar PKn, pendekatan saintifik, sikap sosial. The purpose of this research to investigate the effect of scientific approach on social attitudes and civics learning outcomes of the student of grade VI Jembatan Budaya Primary School, Kuta. The population of this research was 91 students and the number of the sample was 46 students. The data of students social attitudes were collected using questionnaire and the data of civics learning outcomes were collected using multiple-choice test. The data were analyzed using MANOVA. The research is using Posttest Only Control Group Design. The result of the research shows that: 1) there are difference social attitudes between the students following scientific approach and the students following conventional learning model, 2) there are difference civics learning outcomes between the students following scientific approach and the students following conventional learning model, 3) simultaneously, there are difference social attitudes and civics learning outcomes between the students following scientific approach and the students following conventional learning model

Pengaruh Teknik Neighborhood Walk Berorientasi Kontekstual terhadap Kemampuan Menulis dalam Bahasa Inggris Ditinjau dari Kecerdasan Linguistik

Penelitian ini bertujuan untuk mengetahui dan menganalisis pengaruh teknik Neighborhood walk berorientasi kontekstual ditinjau dari kecerdasan linguistik terhadap kemampuan menulis dalam Bahasa Inggris. Penelitian ini dilaksanakan di kelas VIII SMP Negeri 1 Semarapura dengan menggunakan rancangan Post Test Only Control Group Design. Sampel penelitian berjumlah 80 orang yang dipilih dengan menggunakan teknik Random Sampling. Data tentang kemampuan menulis dikumpulkan dengan tes uraian Data yang diperoleh diolah dengan menggunakan analisis varians (ANAVA) dua jalur melalui uji F dan dilanjutkan dengan uji Tukey. Hasil penelitian menunjukkan : (1) secara keseluruhan, kemampuan menulis dalam Bahasa Inggris siswa yang belajar dengan teknik Neighborhood walk lebih tinggi daripada siswa yang belajar dengan teknik pembelajaran konvensional (FA = 18,61 dengan p < 0,05), (2) terdapat pengaruh interaksi antara teknik pembelajaran dengan kecerdasan linguistik terhadap kemampuan menulis Bahasa Inggris siswa (FAB = 52,43 dengan p < 0,05). (3) untuk siswa yang memiliki kecerdasan linguistik tinggi, kemampuan menulis Bahasa Inggris siswa yang belajar dengan teknik Neighborhood walk lebih tinggi daripada siswa yang belajar dengan teknik pembelajaran konvensional (Q = 11,55 dengan p < 0,05), (4) untuk siswa yang memiliki kecerdasan linguistik rendah kemampuan menulis Bahasa Inggris siswa yang belajar dengan teknik pembelajaran konvensional lebih tinggi daripada siswa yang belajar dengan teknik Neighborhood walk (Q = 2,93 dengan p < 0,05). Kata Kunci : Neighborhood walk, Kontekstual, Kecerdasan linguistik, Kemampuan menulis dalam bahasa Inggris This study aimed at finding out and analyzing the influence of neighborhood walk technique with contextual oriented on the increase of English Writing Achievement as Viewed from Linguistic Quotient. This study was conducted at SMP Negeri 1 Semearapura with Post Test Only Control Group Design. The sample of this study consisted of 80 students that were selected by using Random Sampling. The Writing Achievement data obtained by essay test.The data obtained were analyzed by ANAVA two path (Analysis of Varians) with F test, which was followed by Tukey test. The result of the study show the followings : (1) on the whole, the achievement of the students English writing who studied by neighborhood walk technique with contextual oriented was higher than those who studied by conventional (FA = 18,61 with p < 0,05), (2) there are was an interaction effect between the use of teaching learning model and linguistic quotient (FAB = 52,43 with p < 0,05), (3) the student who had high linguistic quotient and studied by neighborhood walk technique with contextual oriented had higher on the increase of English writing achievement than those who had high linguistic quotient and studied by conventional (Q = 11,55 with p < 0,05), and (4) the student who had low linguistic quotient and studied by conventional had higher on the increase of English Writing Achievement than those who had low linguistic quotient and studied by neighborhood walk technique with contextual oriented (Q = 2,93 with p < 0,05). keyword : Neighborhood Walk, Contextual Oriented, Linguistic Quotient,Writing Skil

An interacting quark-diquark model of baryons

A simple quark-diquark model of baryons with direct and exchange interactions is constructed. Spectrum and form factors are calculated and compared with experimental data. Advantages and disadvantages of the model are discussed.Comment: 13 pages, 3 eps-figures, accepted by Phys.Rev. C Rapid Communication

Heteroleptic samarium(III) halide complexes probed by fluorescence-detected L3-edge X-ray absorption spectroscopy

Addition of various oxidants to the near-linear Sm(II) complex [Sm(N††)2] (1), where N†† is the bulky bis(triisopropylsilyl)amide ligand {N(SiiPr3)2}, afforded a family of heteroleptic three-coordinate Sm(III) halide complexes, [Sm(N††)2(X)] (X = F, 2-F; Cl, 2-Cl; Br, 2-Br; I, 2-I). In addition, the trinuclear cluster [{Sm(N††)}3(μ2-I)3(μ3-I)2] (3), which formally contains one Sm(II) and two Sm(III) centres, was isolated during the synthesis of 2-I. Complexes 2-X are remarkably stable towards ligand redistribution, which is often a facile process for heteroleptic complexes of smaller monodentate ligands in lanthanide chemistry, including the related bis(trimethylsilyl)amide {N(SiMe3)2} (N′′). Complexes 2-X and 3 have been characterised by single crystal X-ray diffraction, elemental analysis, multinuclear NMR, FTIR and electronic spectroscopy. The Lα1 fluorescence-detected X-ray absorption spectrum recorded at the Sm L3-edge for 2-X exhibited a resolved pre-edge peak defined as an envelope quadrupole-allowed 2p → 4f transition. The X-ray absorption spectral features were successfully reproduced using time-dependent density functional theoretical (TD-DFT) calculations that synergistically supports the experimental observations as well as the theoretical model upon which the electronic structure and bonding in lanthanide complexes is derived

Pengaruh Pendekatan Kooperatif Tipe Jigsaw Dalam Pembelajaran Bahasa Inggris Terhadap Prestasi Belajar Menulis Ditinjau Dari Bakat Verbal Siswa SMP Negeri 2 Amlapura

Tujuan yang ingin dicapai dalam penelitian ini adalah untuk mengetahui pengaruh penerapan model pembelajaran kooperatif Jigsaw terhadap prestasi belajar menulis ditinjau dari bakat verbal siswa. Untuk mencapai tujuan tersebut dilaksanakan penelitian eksperimental di SMP Negeri 2 Amlapura. Rancangan penelitian ini mengikuti rancangan eksperimen post test only non-equivalent control group design. Populasi dalam penelitian ini adalah semua kelas VIII yang berjumlah 9 kelas. Pemilihan sampel penelitian menggunakan cara random sampling. Berdasarkan hasil penelitian diperoleh bahwa siswa yang memiliki bakat verbal rendah cocok dalam belajar difasiitasi dengan model pembelajaran kooperatif Jigsaw.Kata Kunci : kooperatif Jigsaw, bakat verbal, prestasi The purpose of this study was to find the influence of Cooperative Learning Jigsaw Type upon Students\u27 Achievement in Writing Seen from Verbal Intelligent of Students. This was experimental research in SMPN 2 Amlapura. Design of this research was posttest only non-equivalent control group design. The population of this study was all of students grade VII which were distributed to 9 classes. Random sampling technique was used to determine the sample of this study. Based on the result of data analysis, revealed that students who were having low verbal intelligent was appropriate to be facilitated by using cooperative learning jigsaw type in the process of teaching and learning