4,785 research outputs found
MMI Devices with Weak Guiding Designed in Three Dimensions Using a Genetic Algorithm
We discuss the design of weakly guided multimode interference (MMI) devices using a genetic algorithm. For devices exhibiting a nonnegligible vertical waveguide offset, such as those produced using ion exchange in glass, three-dimensional modeling is required to properly evaluate the device performance. A combination of semivectorial finite difference modeling in two transverse dimensions and mode propagation analysis (MPA) in the propagation direction is used to evaluate the merit of each trial design. An example is provided of a 1 x 4 power splitter designed for ion exchange, which shows considerable improvement over that obtained by self-imaging theory
Determination of Ion Exchange Parameters by a Genetic Algorithm
Modeling the process of ion exchange in glass requires accurate knowledge of the self-diffusion coefficients of the incoming and outgoing ions. Furthermore, correlating the concentration profile of the incoming ions to a change in refractive index requires knowledge of the correlation coefficient. We present a method by which these three parameters can be quickly determined experimentally, using a genetic algorithm. Comparison with published data is presented
Ion-Exchanged Glass Waveguides with Low Birefringence for a Broad Range of Waveguide Widths
Optical communications networks require integrated photonic components with negligible polarization dependence, which typically means that the waveguides must feature very low birefringence. Recent studies have shown that waveguides with low birefringence can be obtained, e.g., by use of silica-on-silicon waveguides or buried ion-exchanged glass waveguides. However, many integrated photonic circuits consist of waveguides with varying widths. Therefore low birefringence is consequently required for waveguides having different widths. This is a difficult task for most waveguide fabrication technologies. We present experimental results on waveguide birefringence for buried silverâsodium ion-exchanged glass waveguides. We show that the waveguide birefringence of the order of 106 for waveguide mask opening widths ranging from 2 to 10 ÎŒm can be obtained by postprocessing the sample through annealing at an elevated temperature. The measured values are in agreement with the values calculated with our modeling software for ion-exchanged glass waveguides. This unique feature of ion-exchanged waveguides may be of significant importance in a wide variety of integrated photonic circuits requiring polarization independent operation
Ion-Exchanged Glass Waveguide Technology: A Review
We review the history and current status of ion exchanged glass waveguide technology. The background of ion exchange in glass and key developments in the first years of research are briefly described. An overview of fabrication, characterization and modeling of waveguides is given and the most important waveguide devices and their applications are discussed. Ion exchanged waveguide technology has served as an available platform for studies of general waveguide properties, integrated optics structures and devices, as well as applications. It is also a commercial fabrication technology for both passive and active waveguide components
Alleviating unemployment traps in Finland: Can the efficiency-equity trade-off be avoided?
Using a new comprehensive tax-benefit model, JUTTA, this paper examines how labour supply incentives â both to participate in the labour force (the âextensiveâ margin) and to supply extra hours of work (the âincentiveâ margin) â have changed in Finland in 1995-2007. The results reveal that the average participation tax rate has decreased by 10 percentage points to 62 per cent. Despite the significant improvement in incentives, some of the unemployed who have children, especially single parents, are still in an unemployment trap, i.e. the disposable family income does not significantly increase if the person is employed. We therefore present simulations where the social security system is reformed, without reducing minimum benefits, so that the income dependence of some of the benefits is reduced. This reform redistributes income to the poor and, at the
same time, improves the incentives to participate in the labour force. We also compare the effects of this policy with those of a set of more traditional type of policies, consisting of across-the-board tax cuts and increases in income support.microsimulation, labour supply, extensive margin,
efficiency-equity trade-off
Generalized Parton Distributions from Hadronic Observables
We propose a physically motivated parametrization for the unpolarized
generalized parton distributions, H and E, valid at both zero and non-zero
values of the skewness variable, \zeta. At \zeta=0, H and E are determined
using constraints from simultaneous fits of experimental data on both the
nucleon elastic form factors and the deep inelastic structure functions.
Lattice calculations of the higher moments constrain the parametrization at
\zeta > 0. Our method provides a step towards a model independent extraction of
generalized distributions from the data that is alternative to the mathematical
ansatz of double distributions.Comment: 4 pages, 2 figures, to appear in the proceedings of DIS 200
Hoivakodin asukkaan ja sairaanhoitajan kohtaaminen. : Sairaanhoitajien ja omaisten kokemuksia.
Honkanen, Julia. Hoivakodin asukkaan ja sairaanhoitajan kohtaaminen. Sairaanhoitajien ja omaisten kokemuksia. Diak Helsinki, syksy 2015, 38s.,4 liitettÀ. Hoitotyön koulutusohjelma, sairaanhoitaja (AMK).
OpinnÀytetyön tarkoituksena oli kuvata sairaanhoitajien kokemuksia hoivakodin asukkaiden kohtaamisesta. Tarkoituksena oli kuvata lisÀksi omaisten kokemuksia sairaanhoitajien ja asukkaiden kohtaamisesta. OpinnÀytetyön tavoitteena oli tiedon lisÀÀminen Hoivan hoivakotien henkilökunnalle asukkaiden kohtaamisesta.
OpinnÀytetyö oli laadullinen eli kvalitatiivinen tutkimus. Teoriapohjana on ollut vanhushoitoon suunnattu kirjallisuus sekÀ aiemmin tehdyt tutkimukset kohtaa-misesta. Aineistoa kerÀttiin lomakekyselyllÀ ja vastauksia saatiin neljÀltÀ sai-raanhoitajalta sekÀ viideltÀ omaiselta. Tulokset analysoitiin sisÀllönanalyysin avulla.
Tutkimuksen tulosten perusteella voidaan sanoa, ettĂ€ sairaanhoitajilla ja omai-silla on samanlainen kokemus siitĂ€, miten asukas kohdataan. Sairaanhoitajien sekĂ€ omaisten mielestĂ€ yksilöllisyys, luottamus sekĂ€ itsemÀÀrÀÀmisoikeus ovat hyvin tĂ€rkeitĂ€ hyvĂ€ssĂ€ kohtaamisessa. LisĂ€ksi heidĂ€n mielestÀÀn sairaanhoita-jan pitÀÀ osata âlukeaâ asukasta. Kohdatessaan asukasta sairaanhoitaja huomioi asukkaan sen hetkisen voinnin ja avuntarpeen. EsteenĂ€ hyvĂ€lle kohtaamiselle sairaanhoitajien ja omaisten mielestĂ€ voi olla muun muassa kiire ja sairaanhoitajan oma asenne työhön.Julia Honkanen. Encountering between a nursing home resident and a nurse. Nursesâ and relativesâ experiences. 38 pages 4 appendices. Helsinki, autumn 2015. Diakonia University of Applied Sciences, Degree Programme in Nursing, Registered Nurse (AMK).
The purpose of the thesis was to describe nursesâ experiences of encounters with nursing home residents. Furthermore, the aim was to describe relativesâ experiences of encounters with nurses and residents.
The aim of the thesis was to provide Hoiva nursing home (Finland) staff with more information about encountering the residents. The qualitative method was used in the thesis. Literature relating to eldercare and previous studies of encounters were the theory basis of the study. The material was gathered using questionnaires. Five answers were received from relatives and four from nurses.
The results were analyzed by using content analysis. According to the results of the study, it can be stated that nurses and relatives have same kinds of experiences on how the resident is encountered. According to the nurses and the relatives, individuality, trust and self-determination play a very important role in good encountering. Additionally, they think that nurses should be able to âreadâ the residents. When encountering the resident, the nurse is assessing the residentâs current health and care need. Nurses and relatives think that e.g haste and the nurseâs own attitude to work can be an obstacle to good encountering
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