Intergenerational redistribution of income through capital funding pension schemes: simulating the Dutch pension fund ABP

In most countries, the largest proportion of the pension benefits that are paid out to the elderly are brought together by the contributions of the active population. This type of financing is known as a Pay-As-You-Go-scheme. In this scheme, an important ‘chain of solidarity' covers for the pension of the preceding generation. So, there is a pattern of winners and losers that is caused by the rates of ageing of the populations, in combination with PAYG-pension schemes. In pension schemes based on the Capital Funding (CF) type, individuals of every generation build up a certain future pension claim. So, every generation builds up its own future pension benefit in this type of scheme. Hence, CF pension schemes are believed not to rely on income flows between generations, since every generation finances its own future pension. The advantage then is that there are no winners or losers, from the generational point of view at least, so that demographic developments cannot jeopardize the system. But, this only holds for Defined-Contribution (DC) pension systems. In practice, we also observe Defined-Benefit (DB) pension systems. In fact, the larger part of the occupational pensions schemes in the Netherlands are DB ones. For this type of schemes it holds that absence of intergenerational income flows is a too optimistic view, though the redistribution is not that strongly as in the case of PAYG schemes. The central question in this contribution is whether intergenerational redistribution of income occurs via Capital Funding in case of DB pension schemes in the Netherlands. To that end we analyse the Dutch civil servants' pension fund in the Dutch dynamic microsimulation model NEDYMAS.microsimulation; ageing; social hypotheses; poverty; inequality

Mean value approximation for closed queueing networks with multi server stations

We fonnulate an approximate recursive relation for the sojourn time, queuelength and throughput of a multi server station, embedded in a closed queueing network. Based on that relation, we derive a mean value approximation and formulate a Schweitzer approximation for solving large networks. Numerical examples show that the approximate mean value algorithm yields accurate results

Global optimization and simulated annealing

In this paper we are concerned with global optimization, which can be defined as the problem of finding points on a bounded subset of Rn in which some real valued functionf assumes its optimal (i.e. maximal or minimal) value. We present a stochastic approach which is based on the simulated annealing algorithm. The approach closely follows the formulation of the simulated annealing algorithm as originally given for discrete optimization problems. The mathematic formulation is extended to continuous optimization problems and we prove asymptotic convergence to the set of global optima. Furthermore, we discuss an implementation of the algorithm and compare its performance with other well known algorithms. The performance evaluation is carried out for a standard set of test functions from the literature. Keywords: global optimization, continuous variables, simulated annealing

Measuring and simulating an 802.3 CSMA/CD LAN

A single 802.3 CatTier Sense Multiple Access/Collision Detection (CSMA/CD) segment is measured resulting in throughput, response times and workstation parameters for several network nodes. During the measurements, the network can'ied an artificial workload with the characteristics of a real-life workload. A simulation of the laboratory test is developed using the artificial workload parameters and the 802.3 CSMA/CD standard of the Consultative Committee for International Telephony and Telegraphy (CCITT). The measurements show that it is possible to determine the workstation parameters with a great accuracy using simple throughput measurements on an otherwise empty network. It is then possible to isolate exact ethernet parameters during throughput measurements on a network with a known workload. The behaviour measured is reproduced in a simple simulation. The results of the simulation conform to the measured values. Some conclusions are that a 802.3 CSMA/CD segment can be measured and simulated with accurate results. The simulation environment is used to model a real-life ethernet network in circumstances that can not be measured in a real-life situation. Parameters that can be used to fine-tune the simulation are the interframe gap time, and the workstation distance on a network

Admixtures to d-wave gap symmetry in untwinned YBa2Cu3O7 superconducting films measured by angle-resolved electron tunneling

We report on an \textit{ab}-anisotropy of $J_{c \parallel b}/J_{c \parallel a}$ and $I_{c}R_{n \parallel b}/I_{c}R_{n \parallel a}\cong 1.2$ in ramp-edge junctions between untwinned YBa$_{2}$Cu$_{3}$O$_{7}$ and $s$% -wave Nb. For these junctions, the angle $\theta$ with the YBa$_{2}$Cu$_{3}$O$_{7}$ crystal b-axis is varied as a single parameter. The $R_{n}$A($\theta$)-dependence presents 2-fold symmetry. The minima in $I_{c}R_{n}$ at $\theta \cong 50^{\circ}$ suggest a real s-wave subdominant component and negligible $d_{xy}$-wave or imaginary s-wave admixtures. The $I_{c}R_{n}$($\theta$)-dependence is well-fitted by 83% $d_{x^{2}-y^{2}}$-, 15% isotropic $s$- and 2% anisotropic s-wave order parameter symmetry, consistent with $\Delta_{b}/\Delta_{a} \cong 1.5$.Comment: 4 pages, 3 figures, to be published in Physical Review Letter

Impulsive and risky decision-making in adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD): The need for a developmental perspective

Item does not contain fulltextImpulsive and risky decision-making peaks in adolescence, and is consistently associated with the neurodevelopmental disorder Attention-Deficit/Hyperactivity Disorder (ADHD), regardless of age. In this brief review, we demonstrate the similarity of theoretical models explaining impulsive and risky decision-making that originate in two relatively distinct literatures (i.e. on adolescence and on ADHD). We summarize research thus far and conclude that the presence of ADHD during adolescence further exacerbates the tendency that is already present in adolescents to make impulsive and risky decisions. We also conclude that much is still unknown about the developmental trajectories of individuals with ADHD with regard to impulsive and risky decision-making, and we therefore provide several hypotheses that warrant further longitudinal research.7 p