Numerical verification of Percival's conjecture in a quantum billiard

In order to verify Percival's conjecture [J. Phys. B 6,L229 (1973)] we study a planar billiard in its classical and quantum versions. We provide an evaluation of the nearest-neighbor level-spacing distribution for the Cassini oval billiard, taking into account relations with classical results. The statistical behavior of integrable and ergodic systems has been extensively confirmed numerically, but that is not the case for the transition between these two extremes. Our system's classical dynamics undergoes a transition from integrability to chaos by varying a shape parameter. This feature allows us to investigate the spectral fluctuations, comparing numerical results with semiclassical predictions founded on Percival's conjecture. We obtain good $global$ agreement with those predictions, in clear contrast with similar comparisons for other systems found in the literature. The structure of some eigenfunctions, displayed in the quantum Poincar\'e section, provides a clear explanation of the conjecture.Comment: 8 pages, 9 figures, to appear in Physical Review E, vol. 57, issue 5 (01 May 1998

Classical and quantum decay of one dimensional finite wells with oscillating walls

To study the time decay laws (tdl) of quasibounded hamiltonian systems we have considered two finite potential wells with oscillating walls filled by non interacting particles. We show that the tdl can be qualitatively different for different movement of the oscillating wall at classical level according to the characteristic of trapped periodic orbits. However, the quantum dynamics do not show such differences.Comment: RevTeX, 15 pages, 14 PostScript figures, submitted to Phys. Rev.

Decay of the Sinai Well in D dimensions

We study the decay law of the Sinai Well in $D$ dimensions and relate the behavior of the decay law to internal distributions that characterize the dynamics of the system. We show that the long time tail of the decay is algebraic ($1/t$), irrespective of the dimension $D$.Comment: 14 pages, Figures available under request. Revtex. Submitted to Phys. Rev. E.,e-mail: [email protected]

Hubungan Minat Belajar dengan Hasil Belajar Matematika Siswa Kelas V Sdn Gugus 4 Kecamatan Limapuluh Kota Pekanbaru

One of several factor which influenced learning achievement is interest. This study aims to determine the relationship between student interest in student learning outcomes in mathematics fifth grade students of SDN Cluster 4 Districts Limapuluhkota Pekanbaru. Pebelitian methods are correlational. Mechanical sampling using cluster. Methods of data collection using a scale and technical documentation of the value of MID second semester. The analysis technique used is the technique of analysis Product Moment. Test requirements analysis in the form of normality and linearity test. Engineering analysis and test requirements analysis using SPSS 20. Results of research is conducted indicates that there is a relationship between interest in learning the mathematics learning outcomes fifth grade students of SDN group 4 Districts Limapuluhkota Pekanbaru obtained rxy of 0.374 with a low correlation level and also interest in learning to give effect to the results studied at 14%. Dioeroleh t test results obtained thitung 3.722 and 1.663 ttabel this case shows that there is a significant relationship between interest in learning the mathematics learning outcomes fifth grade students of SDN Cluster 4 Districts Limapuluhkota Pekanbaru

Transport and dynamical properties of inertial ratchets

In this paper we discuss the dynamics and transport properties of a massive particle, in a time dependent periodic potential of the ratchet type, with a dissipative environment. The directional currents and characteristics of the motion are studied as the specific frictional coefficient varies, finding that the stationary regime is strongly dependent on this parameter. The maximal Lyapunov exponent and the current show large fluctuations and inversions, therefore for some range of the control parameter, this inertial ratchet could originate a mass separation device. Also an exploration of the effect of a random force on the system is performed.Comment: PDF, 16 pages, 7 figure

Analisis Penggunaan Huruf Kapital pada Karangan Deskripsi Siswa Kelas V SD Negeri 1 Pekanbaru

One of the problems in schools is the lack of attention from the teacher to the students' writings. This study aims to determine the ability to use capital letters in the essay description fifth grade students of SD Negeri 1 Pekanbaru. This research is qualitative descriptive. The sampling technique in this research is total sampling. The data collection techniques using the test write (compose) the direct method. Data analysis techniques to analyze the capitalization of 56 fabricated descriptions of students. The use of capital letters consists of 15 aspects, but researchers only use six aspects, such as capital letters used as the first letter of a sentence initial 63.80% (category enough), a capital letter is used as the name of the 62.08% (category enough), capital letters used the first letter of the name of 44.93% (poor category), capital letters used the first letters themselves geography 28.80% (very poor category), capital letters used the first letters the title essay of 75% (both categories ), and capital letters are used the first letters of the title of 43.19% (poor category). From the data analysis it can be concluded that the fifth grade students of SD Negeri 1 Pekanbaru have not been able to use capital letters in accordance with Enhanced Spelling. The average of result shown 52,98% (poor category). The highest percentage in the aspect of capitalization that is used the first letters of the title essay 75% (both categories) and the lowest percentage of aspects of the use of capital letters is used the first letters themselves geography 28.80% (very poor category)