19,451 research outputs found
Decay in W^{1,\infty} for the 1D semilinear damped wave equation on a bounded domain
No full textIn this Ph.D. thesis, we study a semilinear wave equation with nonlinear and time-dependent damping term.
After rewriting the equation as a first order system, we define a class of approximate solutions employing typical tools of hyperbolic systems of conservation laws, such as the Riemann problem. We prove that the initial-boundary value problem is well-posed for initial data in space.
By recasting the problem as a discrete-time nonhomogeneous system, which is related to a probabilistic interpretation of the solution, we provide a strategy to study its long-time behavior uniformly with respect to the mesh size parameter \DX=1/N\to 0.
The proof makes use of the Birkhoff decomposition of doubly stochastic matrices and of accurate estimates on the iteration system as .
Under appropriate assumptions on the nonlinearity, we prove the exponential convergence in of the solution to the first order system towards a stationary solution, as , as well as uniform error estimates for the approximate solutions
On the decay in W^{1,infty} for the 1D semilinear damped wave equation on a bounded domain
No full textIn this paper we study a 2x2 semilinear hyperbolic system of partial differential equations, which is related to a semilinear wave equation with nonlinear, time-dependent damping in one space dimension.
For this problem, we prove a well-posedness result in L^infty in the space-time domain (0,1)x[0,+infty).
Then we address the problem of the time-asymptotic stability of the zero solution and show that, under appropriate conditions,
the solution decays to zero at an exponential rate in the space L^{infty}. The proofs are based on the analysis of the invariant domain
of the unknowns, for which we show a contractive property. These results can yield a decay property in W^{1,infty} for the corresponding solution to the semilinear wave equation
Decay of approximate solutions for the damped semilinear wave equation on a bounded 1d domain
No full textIn this paper we study the long time behavior for a semilinear wave equation with space- dependent and nonlinear damping term. After rewriting the equation as a rst order system, we de ne a class of approximate solutions that employ tipical tools of hyperbolic systems of conservation laws, such as the Riemann problem. By recasting the problem as a discrete- time nonhomogeneous system, which is related to a probabilistic interpretation of the solution, we provide a strategy to study its long-time behavior uniformly with respect to the mesh size parameter ∆x = 1/N → 0. The proof makes use of the Birkhoff decomposition of doubly stochastic matrices and of accurate estimates on the iteration system as N → ∞. Under appropriate assumptions on the nonlinearity, we prove the exponential convergence in L∞ of the solution to the rst order system towards a stationary solution, as t → +∞, as well as uniform error estimates for the approximate solutions
The Quality of Student Services Provided by the Deanship of Student Affairs at Sultan Qaboos University
No full textThis study aimed to investigate the quality of student services provided by the Deanship of Student Affairs at the Sultan Qaboos University. The study sample consisted of 610 students. Data were collected using a questionnaire consisting of 59 items distributed in seven areas which are: social services, housing services, and food services, and counseling and religious guidance services, cultural and artistic services, sports activities, and sustainable training services. The results showed that the highest mean of the responses is in the counseling and religious guidance 3.79, while the lowest mean is for the area of student food services 2.82.the Results of (MANOVA) showed that the quality of services provided by the Deanship of Student Affairs for students for female was a higher level compared with males in the areas of social services, housing services and sustainable training services. As for the results on the year variable, the result of the study revealed that there are statistically significant differences (α=0.05) related to the field of social services in favor of the second year students. Also the results showed that there are statistically significant differences related to students' points of view in humanities colleges in the areas of social services 3.37, and sustainable training 3.27, while in the area of religious guidance services it is in favor of scientific colleges 3.87. Based on the results of this study, many recommendations and suggestions were developed. </jats:p
Determination of the transformation exponent s from experiments at constant heating rate
No full textThe transformation exponent s is a characteristic of the mechanism of a reaction and contains information on nucleation rate and type of growth; it corresponds to the Avrami parameter n in isothermal experiments. Two methods for the determination of s from experiments performed at constant heating rate are presented. They consist of plotting either the logarithm of the reaction rate or of the amount transformed versus 1/T, and s can subsequently be calculated from the slope of the initial straight line. The methods are successfully applied to precipitation in Al-6at%Si, GPB-zone formation in Al-Cu-Mg based alloys, and recrystallisation of deformed FCC metals
"Madinat al-zahara, decoración de piedra arenisca. Estilo califal.(941-942) Mezquita de Medina Al-zahra"
No full textLa fotografía está montada en un soporte secundario de cartón con las medidas de 265 x 205 mm1 positivo en b/n 228x 154 mmSignatura antigua R.1833Cuatro fragmentos decorativos, restos de cenefas, de piedra arenisca y decoración vegetal, encontrados en la excavación de la mezquita de medina al-zahra, y pertenecientes a los años 941-942 montadas sobre fondo oscuro de telaUnidad documenta
Une source arabe de Saadia, le Kitâb al-Zahra d'Aboû Bakr Ibn Dawoûd
No full textVajda Georges. Une source arabe de Saadia, le Kitâb al-Zahra d'Aboû Bakr Ibn Dawoûd. In: Revue des études juives, tome 92, n°184, avril-juin 1932. pp. 146-150
THE INFLUENCE OF SIDE FRICTION ON TRAFFIC ON FATIMA AL-ZAHRA STREET IN KARBALA: CAUSES, RESULTS AND SOLUTIONS
No full textSide friction is considered one of the main reasons for reducing the efficiency of traffic in urban streets and is caused by a number of factors, such as parking vehicles on the side of the road, pedestrians crossing in places not intended for them, vehicles entering the main road from secondary roads and leaving it on secondary roads, etc. The scientific novelty of this work lies in the fact that for the first time, as far as we know, it provides a statistical description of the influence of Side friction factors on traffic efficiency on Fatima Al-Zahra Street in Karbala, as well as on the classification of roads. The results of the study showed that side friction is responsible for significantly reducing the operating efficiency of the studied road, as well as reducing the road classification.
Purpose: determination the effect of side friction on the efficiency of traffic on Fatima Zahra Street in Karbala and to determine the optimal solutions to improve the efficiency of traffic on this street.
Methodology. In this work, both experimental methods of data collection and statistical methods of their processing were used.
Results of the study have shown that Side friction is responsible for a decrease in the operational efficiency of the studied road by an amount in the range of 62.16-86.3%, as well as a decrease in the road classification from I or II to IV.
Practical implications. It is recommended to apply the results obtained from the Karbala Traffic Management Department
"Decoración piedra arenisca califal. S. X. Mezquita de Madinat al-zahra"
No full textLa fotografía está montada en un soporte secundario de cartón con las medidas de 266 x 205 mm1 positivo en b/n 226 x 175 mmSignatura antigua R.1849Composición de cinco fragmentos de piedra arenisca de estilo califal del siglo X, aparecidos en las excavaciones de la Mezquita de Medinat al-zahra; con motivos vegetalesUnidad documenta
PEMAHAMAN PEMBELAJARAN WACANA MELALUI HUMOR TERHADAP MINAT BACA SISWA PADA SD IT SAKINAH AZ-ZAHRA JALAN LINTAS SIMPANG DOLOK DUSUN I DESA 4 NEGERI KECAMATAN 50 KABUPATEN BATU BARA
No full textPenelitian ini berjudul “Pemahaman Pembelajaran Wacana Melalui Humor Terhadap Minat Baca Siswa Pada SD-IT Sakinah AZ-Zahra Jalan Lintas Simpang Dolok Dusun I Desa 4 Negeri Kecamatan 50 Kabupaten Batu Bara”. Tujuan penelitian ini adalah: (1) Menganalisis pemahaman pembelajaran wacana melalui humor terhadap minat baca siswa di SD-IT Sakinah Az-Zahra Kecamatan Lima Puluh Kabupaten Batu Bara tahun pembelajaran 2015-2016, (2) Upaya meningkatkan minat baca siswa yang dilakukan guru melalui wacana humor di SD-IT Sakinah Az-Zahra Kecamatan Lima Puluh Kabupaten Batu Bara tahun pembelajaran 2015-2016 dengan jumlah populasi sebanyak 60 siswa. Dari populasi tersebut diambil sampel 60 siswa pada SD-IT Sakinah AZ-Zahra Jalan Lintas Simpang Dolok Dusun I Desa 4 Negeri Kecamatan 50 Kabupaten Batu Bara. Teknik pengumpulan data yang digunakan adalah dengan menggunakan angket yang diberikan kepada setiap responden. Data diproses dengan menggunakan SPSS versi 20.0 for windows. Teknik analisis data yang digunakan adalah regresi linier sederhana. Berdasarkan hasil penelitian diketahui bahwa nilai rata-rata wacana humor siswa kelas V dan VI SD-IT Sakinah Az-Zahra Kecamatan Lima Puluh Kabupaten Batu Bara tahun pembelajaran 2015-2016 adalah 75,9 (tergolong baik). Sedangkan nilai rata-rata minat baca siswa kelas V dan VI SD-IT Sakinah Az-Zahra Kecamatan Lima Puluh Kabupaten Batu Bara tahun pembelajaran 2015-2016 adalah 70,3 (tergolong sering). Berdasarkan hasil diketahui bahwa nilai rata-rata minat baca siswa kelas SD-IT Sakinah Az-Zahra Kecamatan Lima Puluh Kabupaten Batu Bara tahun pembelajaran 2015-2016. Besarnya hubungan pembelajaran wacana melalui humor dengan minat baca siswa adalah 42,25% berada pada kreteria ada korelasi. Simpulan ini diambil berdasarkan hasil analisis yang telah dilakukan dengan menemukan harga r hitung > r table yaitu harga r hitung yang diperoleh sebesar 0,65. Sedangkan harga t table dengan jumlah sampel N = 60 dan tingkat kesalahan 5% sebesar 0,254. Korelasi antara variabel X dan Y berada pada kategori ada korelasi. Artinya pembelajaran wacana melalui humor terhadap siswa sangat dipengaruhi oleh minat baca
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