Intervalos de confiança para rendas vitalícias: aplicação a fundos de pensões

Esta dissertação tem por objetivo estabelecer intervalos de confiança para rendas vitalícias, que podem vir a ser aplicados no cálculo de responsabilidades atuariais. Para este efeito, foi ne-cessário fazer uma revisão sobre conceitos de mortalidade, tempo de vida futura e rendas vitalí-cias. Posteriormente, serão apresentadas relações entre rendas vitalícias e variáveis aleatórias, que dependem da aleatoriedade do tempo de vida futura. De seguida, serão obtidos os intervalos de confiança para as rendas vitalícias considerando o Teorema Limite Central de Lyapunov, e será elaborada uma revisão de alguns conceitos sobre fundos de pensões para enquadramento da aplicação prática. Por último, será efetuada uma aplicação prática das metodologias desenvolvidas ao longo da dissertação, onde serão apresentados intervalos de confiança para o cálculo das responsabili-dades de um plano de pensões. A construção de intervalos de confiança para as responsabilidades atuariais, custo normal ou mesmo valor atual dos benefícios totais traduz-se numa mais-valia para a gestão de um fundo. Por vezes a estimação pontual de um parâmetro não fornece informação suficiente sobre esse mesmo parâmetro, é importante questionarmo-nos sobre a proximidade dessa estimativa ao seu verdadeiro valor.

The Biological bulletin.

v. 39 (1920)

Blanket Curing to Promote Early Strength Concrete, MLR-87-7, 1989

Fast Track concrete has proven to be successful in obtaining high early strengths. This benefit does not come without cost. Special Type III cement and insulating blankets to accelerate the cure add to its expense when compared to conventional paving. This research was intended to determine the benefit derived from the use of insulating blankets to accelerate strength gain in three concrete mixes using Type I cement. The goal was to determine mixes and curing procedures that would result in a range of opening times. This determination would allow the most economical design for a particular project by tailoring it to a specific time restraint. Three mixes of various cement content were tested in the field. Flexural beams were cast for each mix and tested at various ages. Two test sections were placed for each mix, one section being cured with the addition of insulating blankets and the other being cured with only conventional curing compound. Iowa Department of Transportation specifications require 500 psi flexural strength before a pavement can be opened to traffic. Concrete with Fast Track proportions (nominal 7 1/2 bag), Type I cement, and insulating blankets reached that strength in approximately 36 hr, a standard mix (nominal 6 1/2 bag) using the blankets in approximately 48 hr, and the Fast Track proportions with Type I cement without blankets in about 60 hr. The results showed a significant improvement in early strength gain with the use of insulating blankets.

L'Écho de Paris

1928/06/11 (Numéro 16901).

Coherent Stranski-Krastanov growth in 1+1 dimensions with anharmonic interactions: An equilibrium study

The formation of coherently strained three-dimensional (3D) islands on top of the wetting layer in the Stranski-Krastanov mode of growth is considered in a model in 1 + 1 dimensions accounting for the anharmonicity and nonconvexity of the real interatomic forces. It is shown that coherent 3D islands can be expected to form in compressed rather than expanded overlayers beyond a critical lattice misfit. In expanded overlayers the classical Stranski-Krastanov growth is expected to occur because the misfit dislocations can become energetically favored at smaller island sizes. The thermodynamic reason for coherent 3D islanding is incomplete wetting owing to the weaker adhesion of the edge atoms. Monolayer height islands with a critical size appear as necessary precursors of the 3D islands. This explains the experimentally observed narrow size distribution of the 3D islands. The 2D-3D transformation takes place by consecutive rearrangements of mono- to bilayer, bi- to trilayer islands, etc., after the corresponding critical sizes have been exceeded. The rearrangements are initiated by nucleation events, each one needing to overcome a lower energetic barrier than the one before. The model is in good qualitative agreement with available experimental observations.

Curs de preparació per a la Formació Professional. 'Curso de preparación para la Formación Profesional'.

Incidir y mejorar en un grupo de alumnos de primero de FP en los siguientes aspectos: reconciliar los alumnos con el medio escolar, despertarles el interés por el trabajo y el estudio, aumentar el nivel de conocimientos, especialmente en Lenguaje y Matemáticas, dar elementos racionales que les permitan escoger especialidad con conocimiento de causa y normalizar el Catalán como vehículo comunicativo en la actividad escolar. 44 sujetos de primero de FP del Instituto Politécnico de Formación Profesional de Manresa que reúnen la característica común de poseer una nota global como máximo de 3'5 en una prueba de selección sobre conocimientos de la materia. Se separa la muestra en dos grupos de 22 sujetos. Realiza una estructuración del curso, una programación de las diferentes materias del curso, especificando objetivos, contenidos, metodología, actividades, evaluación y actividades extraescolares. Aplica el programa durante el curso y realiza un análisis de los datos obtenidos mediante porcentajes. Aplica una encuesta y unas entrevistas a los padres y alumnos y realiza una valoración del cumplimiento de los objetivos propuestos. Crea unas pruebas elementales de contenido, una encuesta y realiza entrevistas. Estadísticos descriptivos. Si no se da una revisión a fondo de la FP1 en una línea paralela a las intenciones que han inspirado este estudio se continuará produciendo un fracaso escolar muy notable.

Erfarenheter i akademins tassemarker

Sociologisk Forsknings digitala arkiv

Morphometric analysis of the intestine of domestic quails (Coturnix coturnix japonica) treated with different levels of dietary calcium

The aim of this study was to perform a morphometric analysis of the various parts of the intestine of the domestic quail. Twenty-four female quails (Coturnix coturnix japonica) aged 37 weeks were used and accommodated in laying cages for 12 weeks. Each group was fed a standardized diet containing different quantities of calcium: 2.0%, 2.5%. 3.0% and 3.5%. The birds were weighed, killed, and samples of 1 cm were collected from the duodenum, jejunum and ileum and submitted to the histological routine. The sections obtained were stained in haematoxylin & eosin (H&E). For morphometric analysis, 30 villi and 30 crypts of each segment of the small intestine were measured in order to determine the height and area of the villi, as well as the depth of the crypts. The results showed that although the integrity of the gastrointestinal tract was maintained in all the birds treated with the different calcium levels, a calcium level of 3.0% showed the most promise, as the levels of 2.0% and 2.5% did not cause any alteration in the intestinal tract. Furthermore, a calcium level of 3.5% led to a significant reduction in the height of the villosities, and in consequence reduced the digestive and absorptive capabilities.

Total Synthesis of (+)-trans-Trikentrin A

Several syntheses have already been reported for cis-trikentrins and herbindoles, which are indole alkaloids unsubstituted at the C2 and C3 positions that bear a trans-1,3-dimethylcyclopentyl unit. Herein, we describe the first asymmetric and stereoselective synthesis of the more challenging trans-trikentrin A as its naturally occurring isomer. Different approaches were investigated and the strategy of choice was a combination of an enzymatic kinetic resolution and a thallium(III)-mediated ring contraction. The antiproliferative activities of the natural product and related intermediates have been tested against human tumor cell lines, leading to the discovery of new compounds with potent antitumor activity.

EEG amplitude modulation analysis for semi-automated diagnosis of Alzheimer's disease

Recent experimental evidence has suggested a neuromodulatory deficit in Alzheimer's disease (AD). In this paper, we present a new electroencephalogram (EEG) based metric to quantitatively characterize neuromodulatory activity. More specifically, the short-term EEG amplitude modulation rate-of-change (i.e., modulation frequency) is computed for five EEG subband signals. To test the performance of the proposed metric, a classification task was performed on a database of 32 participants partitioned into three groups of approximately equal size: healthy controls, patients diagnosed with mild AD, and those with moderate-to-severe AD. To gauge the benefits of the proposed metric, performance results were compared with those obtained using EEG spectral peak parameters which were recently shown to outperform other conventional EEG measures. Using a simple feature selection algorithm based on area-under-the-curve maximization and a support vector machine classifier, the proposed parameters resulted in accuracy gains, relative to spectral peak parameters, of 21.3% when discriminating between the three groups and by 50% when mild and moderate-to-severe groups were merged into one. The preliminary findings reported herein provide promising insights that automated tools may be developed to assist physicians in very early diagnosis of AD as well as provide researchers with a tool to automatically characterize cross-frequency interactions and their changes with disease.