| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Aarts, Clara
(author)
-
Exclusive breastfeeding-Does it make a difference? : A longitudinal, prospective study of daily feeding practices, health and growth in a sample of Swedish infants
- 2001
-
Doctoral thesis (other academic/artistic)abstract
- The concept of exclusive breastfeeding in relation to daily feeding practices and to health and growth of infants in an affluent society was examined. In a descriptive longitudinal prospective study 506 mother-infant pairs were followed from birth through the greater part of the first year. Feeding was recorded daily, and health and growth were recorded fortnightly. Large individual variations were seen in breastfeeding patterns. A wide discrepancy between the exclusive breastfeeding rates obtained from "current status" data and data "since birth" was found.Using a strict definition of exclusive breastfeeding from birth and taking into account the reasons for giving complementary feeding, the study showed that many exclusively breastfed infants had infections early in life, the incidence of which increased with age, despite continuation of exclusive breastfeeding. However, truly exclusively breastfed infants seem less likely to suffer infections than infants who receive formula in addition to breast milk. Increasing formula use was associated with an increasing likelihood of suffering respiratory illnesses. The growth of exclusively breastfed infants was similar to that of infants who were not exclusively breastfed. The health of newborn infants during the first year of life was associated with factors other than feeding practices alone. Some of these factors may be prenatal, since increasing birth weight was associated with an increasing likelihood of having respiratory symptoms, even in exclusively breastfed infants. However, exclusive breastfeeding was shown to be beneficial for the health of the infant even in an affluent society.
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
- Abbasian, Saeid, 1961-
(author)
-
Integration på egen hand : En studie av invandrade kvinnoföretagare i Sverige
- 2003
-
Doctoral thesis (other academic/artistic)abstract
- The principal aim of this thesis is to discover and analyse the motives that make immigrant women start their own businesses in Sweden and to investigate whether this is a way to achieve integration in working life. The empirical material consists of two types of interviews. One type consisted of interviews with five experts on labour market issues, and the other of interviews with 16 female entrepreneurs of Iranian, Chilean and Turkish origin having their own business in the Greater Stockholm region. Results from the first set of interviews indicate that female immigrants who independently start their enterprise rely mainly on their own resources of power and abilities. They are either women with class resources such as higher educations, previous work experience, language abilities and economic savings, or young women with certificates from high schools or universities. The social environment where they grew up, the gender structure and gender roles in the family before and after immigration and time of residence in Sweden also influence the extent to which women immigrants can act independently. According to the experience of the experts, the motives for starting their business are either different structural reasons, e.g. unemployment, lack of suitable or well-paying jobs, lay-offs etc, or personal reasons such as having a meaningful occupation, to support the family, to earn money of their own, to be independent from men and strive for a better standard of living etc. Results from the second set of interviews indicate that the most important resource these women have used when establishing their businesses is class resources such as education and adequate training, different types of work experiences, human capital and in addition to this economic savings. For many of the women in this sample different structural reasons, like unemployment, lack of good job opportunities, discrimination on work places, merge with personal reasons such as strivings to achieve independence, being one’s own boss, to realize one’s plans and ambitions, when starting their business. Independent entrepreneurship is a good way for immigrant women to be integrated in working life especially if they start within certain branches. These are branches in which the women have appropriate university education or vocational training, previous work experience or which correspond to their personal interests. In addition immigrant women become more integrated if an education received abroad is treated as equivalent to the parallel Swedish education or degree. A further factor promoting integration is if they can fully exploit their capacities when developing their own businesses. These conditions help them to feel much more satisfaction in working life as women identify themselves with their actual profession and feel that they have found the “right place” for themselves in the society.
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
- Abd-Elrady, Emad
(author)
-
An adaptive grid point RPEM algorithm for harmonic signal modeling
- 2001
-
Reports (other academic/artistic)abstract
- Periodic signals can be modeled as a real wave with unknown period in cascade with a piecewise linear function. In this report, a recursive Gauss-Newton prediction error identification algorithm for joint estimation of the driving frequency and the parameters of the nonlinear output function parameterized in a number of adaptively estimated grid points is introduced. The Cramer-Rao bound (CRB) is derived for the suggested algorithm. Numerical examples indicate that the suggested algorithm gives better performance than using fixed grid point algorithms and easily can be modified to track both the fundamental frequency variations and the time varying amplitude.
|
|
| 17. |
|
|
| 18. |
- Abd-Elrady, Emad, et al.
(author)
-
Bias Analysis in Least Squares Estimation of Periodic Signals Using Nonlinear ODE's
- 2004
-
Reports (other academic/artistic)abstract
- Periodic signals can be modeled by means of second-order nonlinear ordinary differential equations (ODE's). The right hand side function of the ODE is parameterized in terms of known basis functions. The least squares algorithm developed for estimating the coefficients of these basis functions gives biased estimates, especially at low signal to noise ratios. This is due to noise contributions to the periodic signal and its derivatives evaluated using finite difference approximations. In this paper an analysis for this bias is given.
|
|
| 19. |
- Abd-Elrady, Emad
(author)
-
Convergence of the RPEM as applied to harmonic signal modeling
- 2000
-
Reports (other academic/artistic)abstract
- Arbitrary periodic signals can be estimated recursively by exploiting the fact that a sine wave passing through a static nonlinear function generates a spectrum of overtones. The estimated signal model is hence parameterized as a real wave with unknown period in cascade with a piecewise linear function. The driving periodic wave can be chosen depending on any prior knowledge. The performance of a recursive Gauss-Newton prediction error identification algorithm for joint estimation of the driving frequency and the parameters of the nonlinear output function is therefore studied. A theoretical analysis of local convergence to the true parameter vector as well as numerical examples are given. Furthermore, the Cramer-Rao bound (CRB) is calculated in this report.
|
|
| 20. |
- Abd-Elrady, Emad
(author)
-
Harmonic signal modeling based on the Wiener model structure
- 2002
-
Licentiate thesis (other academic/artistic)abstract
- The estimation of frequencies and corresponding harmonic overtones is a problem of great importance in many situations. Applications can, for example, be found in supervision of electrical power transmission lines, in seismology and in acoustics. Generally, a periodic function with an unknown fundamental frequency in cascade with a parameterized and unknown nonlinear function can be used as a signal model for an arbitrary periodic signal. The main objective of the proposed modeling technique is to estimate the fundamental frequency of the periodic function in addition to the parameters of the nonlinear function.The thesis is divided into four parts. In the first part, a general introduction to the harmonic signal modeling problem and different approaches to solve the problem are given. Also, an outline of the thesis and future research topics are introduced.In the second part, a previously suggested recursive prediction error method (RPEM) for harmonic signal modeling is studied by numerical examples to explore the ability of the algorithm to converge to the true parameter vector. Also, the algorithm is modified to increase its ability to track the fundamental frequency variations.A modified algorithm is introduced in the third part to give the algorithm of the second part a more stable performance. The modifications in the RPEM are obtained by introducing an interval in the nonlinear block with fixed static gain. The modifications that result in the convergence analysis are, however, substantial and allows a complete treatment of the local convergence properties of the algorithm. Moreover, the Cramér–Rao bound (CRB) is derived for the modified algorithm and numerical simulations indicate that the method gives good results especially for moderate signal to noise ratios (SNR).In the fourth part, the idea is to give the algorithm of the third part the ability to estimate the driving frequency and the parameters of the nonlinear output function parameterized also in a number of adaptively estimated grid points. Allowing the algorithm to automatically adapt the grid points as well as the parameters of the nonlinear block, reduces the modeling errors and gives the algorithm more freedom to choose the suitable grid points. Numerical simulations indicate that the algorithm converges to the true parameter vector and gives better performance than the fixed grid point technique. Also, the CRB is derived for the adaptive grid point technique.
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
- Abdu, Yassir Ahmed Mohamed, 1966-
(author)
-
Mössbauer Spectroscopy of Meteoritic and Synthetic Fe-Ni Alloys
- 2004
-
Doctoral thesis (other academic/artistic)abstract
- This thesis reports on the results of investigating Fe-containing minerals in meteorites, with focus on Fe-Ni minerals and their magnetic properties, along with some synthetic Fe-Ni analogues. The New Halfa meteorite, which fell in Sudan 1994, has been studied using Mössbauer spectroscopy, X-ray diffraction, and electron microprobe analysis techniques, and classified as an ordinary L-type chondrite of petrologic type 4. Mössbauer spectra of taenite-enriched samples from the metal particles of the New Halfa (L4) and Al Kidirate (H6) meteorites identify the following γ (fcc) Fe-Ni phases: the ferromagnetic atomically ordered taenite (tetrataenite) with ~ 50 at % Ni, the ferromagnetic disordered taenite with ~ 50 at % Ni, the low-Ni (~ 25 at %) paramagnetic taenite (antitaenite). The presence of the superstructure of tetrataenite is confirmed by synchrotron X-ray diffraction.Fe-rich γ (fcc) Fe-Ni alloys with compositions Fe79Ni21, Fe76Ni24, and Fe73Ni27, which serve as synthetic analogues of antitaenite, are prepared by mechanical alloying and subsequent annealing at 650 °C. The Mössbauer results indicate that these alloys are inhomogeneous and contain a high moment (HM) ferromagnetic Ni-rich phase (> 30 at % Ni) and a low moment (LM) paramagnetic Fe-rich phase, which orders antiferromagnetically at low temperature. The coexistence of these phases is attributed to phase segregation occurring on short range, probably nanometer scale, consistent with the Fe-Ni phase diagram below 400 °C where there is a miscibility gap associated with a spinodal decomposition in alloys with < 50 at % Ni.The combined high field Mössbauer spectroscopy and SQUID magnetometry results on these alloys at room temperature indicate large induced local magnetic moments in the paramagnetic part of the sample, which increases with increasing the Ni content. The results, when compared with the high field Mössbauer results on antitaenite from the metal particle of Al Kidirate and New Halfa meteorites may be used to estimate the Ni content of antitaenite in meteorites.High pressure 57Fe Mössbauer spectroscopy measurements up to ~ 41 GPa have been carried out at room temperature using the diamond anvil cell (DAC) technique in order to investigate the magnetic properties of γ (fcc) 57Fe53Ni47 alloy. The results indicate a pressure induced Invar effect at ~ 7 GPa and a non-magnetic or paramagnetic state above 20 GPa, demonstrating the volume dependence of the magnetic moment of γ (fcc) Fe-Ni alloys.
|
|
| 25. |
- Abdulla, Parosh Aziz, et al.
(author)
-
Algorithmic Improvements in Regular Model Checking
- 2003
-
Reports (other academic/artistic)abstract
- Regular model checking is a form of symbolic model checking for parameterized and infinite-state systems, whose states can be represented as finite strings of arbitrary length over a finite alphabet, in which regular sets of words are used to represent sets of states. In earlier papers, we have developed methods for computing the transitive closure (or the set of reachable states) of the transition relation, represented by a regular length-preserving transducer. In this paper, we present several improvements of these techniques, which reduce the size of intermediate approximations of the transitive closure: One improvement is to pre-process the transducer by \em bi-determinization, another is to use a more powerful equivalence relation for identifying histories (columns) of states in the transitive closure. We also present a simplified theoretical framework for showing soundness of the optimization, which is based on commuting simulations. The techniques have been implemented, and we report the speedups obtained from the respective optimizations.
|
|
