650 research outputs found
Optimal Control of Nonlocal Thermistor Equations
We are concerned with the optimal control problem of the well known nonlocal
thermistor problem, i.e., in studying the heat transfer in the resistor device
whose electrical conductivity is strongly dependent on the temperature.
Existence of an optimal control is proved. The optimality system consisting of
the state system coupled with adjoint equations is derived, together with a
characterization of the optimal control. Uniqueness of solution to the
optimality system, and therefore the uniqueness of the optimal control, is
established. The last part is devoted to numerical simulations.Comment: Submitted 21-March-2012; revised 11-June-2012; accepted 13-June-2012;
for publication in the International Journal of Contro
Optimal Control of the Thermistor Problem in Three Spatial Dimensions
This paper is concerned with the state-constrained optimal control of the
three-dimensional thermistor problem, a fully quasilinear coupled system of a
parabolic and elliptic PDE with mixed boundary conditions. This system models
the heating of a conducting material by means of direct current. Local
existence, uniqueness and continuity for the state system are derived by
employing maximal parabolic regularity in the fundamental theorem of Pr\"uss.
Global solutions are addressed, which includes analysis of the linearized state
system via maximal parabolic regularity, and existence of optimal controls is
shown if the temperature gradient is under control. The adjoint system
involving measures is investigated using a duality argument. These results
allow to derive first-order necessary conditions for the optimal control
problem in form of a qualified optimality system. The theoretical findings are
illustrated by numerical results
Evaluasi Kepuasan Penghuni pada Fasilitas Hunian Perusahaan Industri Perkebunan
Evaluation of the occupant satisfaction in the residential facilities of plantation industry wa a spesific research. The specific of research was caused its occupancy status was the royalty. The status of the royalty only owned for occupant still working in the company. The propose of this research was to find out the most important residential factors and the occupant satisfaction. The research also aimed at determining the relationship between occupant characteristic and its occupancy factors. The method of this research was a combination method between qualitative abd quantitative and it was conducted sequentially. Method of data collection and data analysis were carried out in accordingly. Analysis in qualitative data was content analysis while quantitative data used statistical methods such as frequency analysis, factor analysis, and correlation analysis. This research found that the quality and condition of building were the most important residential factors but the occupants did not feel satisfied. Education and income were the occupancy characteristics which correlated with the occupancy factor such as bathroom and the relationship of space front yard area. Another correlation wa indicated by the education characteristic and the flexibility factors modified the function and form. ---Evaluasi Kepuasan penghuni pada fasilitas hunian industri perkebunan merupakan penelitian yang khas. Kekhasan kajian ini disebabkan status huniannya yang bersifat hak pakai. Status hak pakai hanya dimiliki selama penghuni masih bekerja di perkebunan tersebut. Penelitian ini bertujuan untuk mengetahui faktor-faktor hunian paling yang dianggap penting dan dirasakan puas oleh penghuni. Penelitian ini juga bertujuan untuk mengetahui hubungan antara karakteristik penghuni dan faktor-faktor huniannya. Metode yang digunakan pada penelitian ini merupakan metode gabungan antara kualitatif dan kuantitatif yang dilakukan secara berurutan. Metode pengumpulan dan analisis data dilakukan sesuai tahap penelitiannya. Analysis yang digunakan pada data kualitatif berupa content analysis sedangan pada data kuantitatif menggunakan metode statistik berupa analisis frekuensi analisis faktor, dan analisis korelasi. Penelitian ini menemukan bahwa kondisi dan kualitas bangunan merupakan faktor hunian yang paling dianggap penting namun tidak dirasakan paling puas oleh penghuni. Pendidikan dan penghasilan merupakan karakteristik penghuni yang berkorelasi dengan faktor-faktor hunian berupa KM/WC dan hubungan ruang serta luas halaman depan. Korelasi lainnya ditunjukkan oleh karakteristik pendidikan dan faktor keleluasaan mengubah fungsi dan bentuk
Perturbation Theory for Metastable States of the Dirac Equation with Quadratic Vector Interaction
The spectral problem of the Dirac equation in an external quadratic vector
potential is considered using the methods of the perturbation theory. The
problem is singular and the perturbation series is asymptotic, so that the
methods for dealing with divergent series must be used. Among these, the
Distributional Borel Sum appears to be the most well suited tool to give
answers and to describe the spectral properties of the system. A detailed
investigation is made in one and in three space dimensions with a central
potential. We present numerical results for the Dirac equation in one space
dimension: these are obtained by determining the perturbation expansion and
using the Pad\'e approximants for calculating the distributional Borel
transform. A complete agreement is found with previous non-perturbative results
obtained by the numerical solution of the singular boundary value problem and
the determination of the density of the states from the continuous spectrum.Comment: 10 pages, 1 figur
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Adaptive Evolution and the Birth of CTCF Binding Sites in the <i>Drosophila</i> Genome
Changes in the physical interaction between cis-regulatory DNA sequences and proteins drive the evolution of gene expression. However, it has proven difficult to accurately quantify evolutionary rates of such binding change or to estimate the relative effects of selection and drift in shaping the binding evolution. Here we examine the genome-wide binding of CTCF in four species of Drosophila separated by between ∼2.5 and 25 million years. CTCF is a highly conserved protein known to be associated with insulator sequences in the genomes of human and Drosophila. Although the binding preference for CTCF is highly conserved, we find that CTCF binding itself is highly evolutionarily dynamic and has adaptively evolved. Between species, binding divergence increased linearly with evolutionary distance, and CTCF binding profiles are diverging rapidly at the rate of 2.22% per million years (Myr). At least 89 new CTCF binding sites have originated in the Drosophila melanogaster genome since the most recent common ancestor with Drosophila simulans. Comparing these data to genome sequence data from 37 different strains of Drosophila melanogaster, we detected signatures of selection in both newly gained and evolutionarily conserved binding sites. Newly evolved CTCF binding sites show a significantly stronger signature for positive selection than older sites. Comparative gene expression profiling revealed that expression divergence of genes adjacent to CTCF binding site is significantly associated with the gain and loss of CTCF binding. Further, the birth of new genes is associated with the birth of new CTCF binding sites. Our data indicate that binding of Drosophila CTCF protein has evolved under natural selection, and CTCF binding evolution has shaped both the evolution of gene expression and genome evolution during the birth of new genes.</p
Transcripts of unfulfillment : a study of sexual dysfunction and dissatisfaction among Malay-Muslim women in Malaysia
The prevalence of female sexual dysfunction (FSD), or in everyday notion, sexual dissatisfaction, among Malay women remains high, denoting that there are several influences shaping their experience of sex within marriage. This qualitative study identified the perceived effects of social factors in the development of sexual dysfunction among Malay women. Engaging a phenomenological framework, 26 in-depth face-to-face interviews were conducted among married women from Peninsular Malaysia, based on their self-reporting of FSD symptoms. All sessions were audio-recorded and the data were transcribed verbatim and managed in the ATLAS.ti software before being analysed. The three themes that emerged—‘sex is taboo and culturally unacceptable’, ‘self-ignorance about sex’, and ‘lack of husband’s role in mutual sexual enjoyment’—suggest some influence of Islamic teachings and cultural conduct, as in Adat, on sexuality in society. However, a lack of knowledge and nonadherence to positive values and teachings around sexual satisfaction between men and women, as espoused through the Islamic religion, have affected woman’s sexual functions and coupling relationship even more significantly. The results of this qualitative study show that a formal, culturally sensitive, and comprehensive sex education programme incorporating both medical and Islamic knowledge may work to effectively reduce FSD
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