Many people invest regularly in sinking funds that track stock market indices. When stock markets themselves sink significantly, as in the current credit crunch, investors face a decision as to whether they should continue paying into a falling fund, or switch payment to a risk-free deposit account until the market recovers. Most financial advice is to keep investing on the grounds that as the ...

We present the construction of a planar vector field that yields the firing rate of a bursting Izhikevich neuron can be read out, while leaving the sub-threshold behavior intact. This planar vector field is used to derive lumped formulations of two complex heterogeneous networks of bursting Izhikevich neurons. In both cases, the lumped model is compared with the spiking network. There is excell...

Lumped and transfer rate constants in ischemic brain tissue must be measured to estimate accurately cerebral glucose utilization by the deoxyglucose method. We studied the bilateral middle cerebral artery occlusion model in 17 cats, 5 with a 1-hour occlusion, 5 with a 4-hour occlusion, and 7 with a sham operation. The time course of cerebral tissue radioactivity (Ci*(t)) was monitored by extern...

Lumped element models, also known as, mass-spring-damper models, are widely used to simulate deformable objects because of their simplicity and computational efficiency. However, the parameters of lumped element models are typically determined in an ad hoc fashion through trial-and-error, as these models are not directly based on continuum mechanics of deformable objects. In this paper, an alte...

If menu costs have a non-negligible lump-sum component and with larger firms having greater benefits from price adjustments, then larger firms will change price more frequently than smaller firms. Data from New Zealand firms support this hypothesis. Price duration decreases as firm size increases. Ordered probit analysis indicates the effect comes primarily from larger firms being more likely t...

concrete shear walls are the most prevalent structural systems resisting lateral loads due to earthquakes in high-rise buildings. very large in-plane stiffness of shear walls provides an excellent drift control in the structure. however, structural damages and early code shortcomings threaten the efficiency of existing structural walls against earthquake. recently, fiber reinforced polymer (frp...

In this paper we present two models for joint stock replenishment and shipment consolidation decisions which arise in the context of vendor managed inventory. Stock replenishment from suppliers or shipment to customers each incurs a lump-sum cost to the vendor. We assume the vendor uses the reorder point, lot-size policy to replenish stock and one of two schemes to dispatch shipment: the time-b...

Three-dimensional solitary waves or lump solitons are known to be solutions to the Kadomtsev–Petviashvili I equation, which models small-amplitude shallow-water waves when the Bond number is greater than 1 3 . Recently, Pego and Quintero presented a proof of the existence of such waves for the Benney–Luke equation with surface tension. Here we establish an explicit connection between the lump s...

This paper analyzes voting on a linear income tax which is redistributed lump sum to the taxpayers. Individuals can evade taxes, which leads to penalties if evasion is detected. Since preferences satisfy neither single peakedness nor single crossing, an equilibrium may not exist. When it does exist, it may have interesting properties, in particular, the poor and the rich may form a coalition ag...