Measurement of the Structure Constant of Refractivity at Optical Wavelengths Using a Scintillometer

The structure constant of the atmospheric refractive index is used for characterizing the turbulence strength and for predicting the scintillation of electromagnetic waves in atmosphere. It is measured continuously in Prague using an optical scintillometer. First monthly and seasonal statistics obtained from the data gathered in the summer 2011 are provided. Lognormal distribution parameters are fitted to the empirical cumulative distribution. The hourly statistics of the structure constant show the typical evolution of turbulence strength during a day

Determinants and consequences of budget reallocations

We investigate the determinants and consequences of budget reallocations, i.e., corrective actions to the budget made during the year. Using proprietary data of a large consumer goods manufacturer, we analyze the extent to which allocation decisions regarding the initial budget drive subsequent reallocations. Whenever scarce resources need to be allocated among a number of individuals, power struggles and politicking behavior are likely to arise, which potentially affects the outcome of the allocation process. We hypothesize and find that one important driver of reallocation decisions is the firm's aim to correct for systematic deviations from the optimal initial budget allocation that are driven by successful lobbying activities during the initial budgeting process. In a more exploratory analysis, we show that such reallocations do not have the desired effects on market-place performance. In particular, budget cuts are negatively associated with a product's change in market share. More surprisingly, while budget boosts do help product lines internally to achieve their sales targets in the last quarter, they do not have a (positive) effect on the change in market share. Most importantly, our results demonstrate that efficient investment planning ex ante is essential to achieve an improvement in market-place performance, highlighting the value of budgeting.Series: Department of Strategy and Innovation Working Paper Serie

The effect of horizontal pay dispersion on the effectiveness of performance-based incentives

In response to general calls for increased transparency in society, pay transparency policies are growing in importance. Given that pay transparency unavoidably gives employees the opportunity to make comparisons between themselves and others, in this study we address the question of how these comparisons impact the incentive effects of performance contingent pay, and consequently their performance outcomes. Specifically, we empirically examine whether horizontal pay dispersion alters the effectiveness of performance-based pay contracts, which firms typically use to incentivize effort. Exploiting our unique access to a large healthcare provider, we document the moderating role of horizontal pay dispersion on the effectiveness of individual monetary incentives at generating increased individual performance. To provide a more nuanced understanding of the moderating effect of pay dispersion, we further examine the boundary conditions of the proposed interaction. In particular, we examine the differential effect of overall pay dispersion on employees that rank high versus low in the pay distribution and disaggregate overall pay dispersion into performance-related versus performance-unrelated pay dispersion. Our findings consistently show a positive moderating effect of pay dispersion when employees are more likely to consider the observed pay dispersion as legitimate, and a negative moderation effect when this is less likely the case. Our study strengthens the understanding of how individual level incentives function in the context of a multi-person firm setting. Our results document that individual incentives are effective, but also suggest that pay dispersion can have a significant influence on the incentive-performance relation. These findings provide some evidence that individuals are concerned not only with their own payout, but also with that of others, and that this concern has a significant impact on individual’s effort provision, and consequently performance.Series: Department of Strategy and Innovation Working Paper Serie

Redundancy of minimal weight expansions in Pisot bases

Motivated by multiplication algorithms based on redundant number representations, we study representations of an integer $n$ as a sum $n=\sum_k \epsilon_k U_k$, where the digits $\epsilon_k$ are taken from a finite alphabet $\Sigma$ and $(U_k)_k$ is a linear recurrent sequence of Pisot type with $U_0=1$. The most prominent example of a base sequence $(U_k)_k$ is the sequence of Fibonacci numbers. We prove that the representations of minimal weight $\sum_k|\epsilon_k|$ are recognised by a finite automaton and obtain an asymptotic formula for the average number of representations of minimal weight. Furthermore, we relate the maximal order of magnitude of the number of representations of a given integer to the joint spectral radius of a certain set of matrices

Prussian Blue-coated interdigitated array electrodes for possible analytical application

Thin films of iron(III) hexacyanoferrate(II) (Prussian Blue) were electrochemically deposited on interdigitated array (IDA) electrodes, yielding systems which can be considered as chemiresistors in sensing alkali metal ion concentrations in an adjacent electrolyte. This is due to the fact that the conductivity of the film being measured by a steady-state current on application of a voltage to the two-fingered electrodes of the IDA depends on both the redox stare of the film and the cation concentration in the electrolyte. From the dependence of the steady-state current on the electrode (bias) potential at variable cation concentrations for different alkali metal ions and for mixtures of alkali metal ions, the possibilities of analytical application were elucidated. In addition, by using the methods of staircase coulometry and scanning conductivity, the electron diffusion coefficient De was determined as a function of the redox state of Prussian Blue. It is concluded that Prussian Blue-coated IDA electrodes are, in principle, suitable as chemiresistors for the determination of alkali metal ion concentrations with increasing selectivity in the series Li < Na < K < Rb < Cs