Scarring effects of unemployment.

Using Norwegian individual register data of young workers, from the period 1986-2008, we analyse whether there are large and persistent negative relationships between unemployment and the risk of repeated unemployment and being out of labour force. A nearest-neighbour propensity score matching method is applied to make the treatment group (the unemployed)and the control group (the employed) as similar as possible. By tracking workers over a 10-year follow-up period, we find that unemployment has a negative effect on later labour market attachment. This is consistent with existing findings in the literature. The negative effects decrease over time. Using the bounding approach proposed by Rosenbaum (2002) to analyse the importance of unobserved variables, our results indicate that a relatively high level of unobserved selection bias could be present in the data before changing the inference. Thus, unemployment leaves young workers with long-term scars.Unemployment persistency; scarring; matching technique.

Manifestation of a nonclassical Berry phase of an electromagnetic field in atomic Ramsey interference

The Berry phase acquired by an electromagnetic field undergoing an adiabatic and cyclic evolution in phase space is a purely quantum-mechanical effect of the field. However, this phase is usually accompanied by a dynamical contribution and cannot be manifested in any light-beam interference experiment because it is independent of the field state. We here show that such a phase can be produced using an atom coupled to a quantized field and driven by a slowly changing classical field, and it is manifested in atomic Ramsey interference oscillations. We also show how this effect may be applied to one-step implementation of multiqubit geometric phase gates, which is impossible by previous geometric methods. The effects of dissipation and fluctuations in the parameters of the pump field on the Berry phase and visibility of the Ramsey interference fringes are analyzed

Electricity Prices, River Temperatures and Cooling Water Scarcity.

Thermal-based power stations rely on water for cooling purposes. These water sources may be subject to incidents of scarcity, environmental regulations and competing economic concerns. This paper analyses the effect of water scarcity and increased river temperatures on German electricity prices from 2002 to 2009. Having controlled for demand effects, the results indicate that the electricity price is significantly impacted by both a change in river temperatures and the relative abundance of river water. An implication is that future climate change will affect electricity prices not only through changes in demand, but also via increased water temperatures and scarcity.Thermal-based power; water scarcity.

Sequentiality versus Simultaneity: Interrelated Factor Demand.

A structural model is developed and estimated by a maximum likelihood routine to investigate interrelated factor demand subject to nonconvex adjustment costs. The dataset concerns Norwegian plants operating in manufacturing industries and it covers the period 1993-2005. The estimates indicate that it is advantageous to adjust the stock of labour and capital simultaneously. The cost advantage of simultaneous changes is small for capital but is large for labour. The empirical results suggest that when estimating separate factor demand models the bias of parameter estimates is most severe in case of labour demand.Factor Demand; Labour; Capital; Interrelation; Nonconvex Adjustment Costs.

Sequentiality versus Simultaneity: Interrelated Factor Demand

A structural model is developed and estimated by a maximum likelihood routine to investigate interrelated factor demand subject to nonconvex adjustment costs. The dataset concerns Norwegian plants operating in manufacturing industries and it covers the period 1993-2005. The estimates indicate that it is advantageous to adjust the stock of labour and capital simultaneously. The cost advantage of simultaneous changes is small for capital but is large for labour. The empirical results suggest that when estimating separate factor demand models the bias of parameter estimates is most severe in case of labour demand.factor demand, labour, capital, interrelation, nonconvex adjustment costs

Interrelated Factor Demand with Nonconvex Adjustment Costs: a Note

In this paper we develop a model to describe a firm’s demand for two production factors which is subject to the presence of nonconvex adjustment costs. In our model simultaneous adjustment of these two production factors may either increase or decrease the total costs incurred by the firm. The magnitude of this change in total costs ultimately determines the likelihood of joint adjustment. We also show that the importance of interrelation is suppressed by large fixed costs.Economics (Jel: A)

Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 1: Analysis and design of stages A, B, and C

A conventional rotor and stator, two dual-airfoil tandem rotors, and one dual-airfoil tandem stator were designed. The two tandem rotors were each designed with different percentages of the overall lift produced by the front airfoil. Velocity diagrams and blade leading and trailing edge metal angles selected for the conventional rotor and stator blading were used in the design of the tandem blading. Rotor inlet hub/tip ratio was 0.8. Design values of rotor tip velocity and stage pressure ratio were 757 ft/sec and 1.30, respectively

BCS-BEC Crossover in Atomic Fermi Gases with a Narrow Resonance

We determine the effects on the BCS-BEC crossover of the energy dependence of the effective two-body interaction, which at low energies is determined by the effective range. To describe interactions with an effective range of either sign, we consider a single-channel model with a two-body interaction having an attractive square well and a repulsive square barrier. We investigate the two-body scattering properties of the model, and then solve the Eagles-Leggett equations for the zero temperature crossover, determining the momentum dependent gap and the chemical potential self-consistently. From this we investigate the dependence of the crossover on the effective range of the interaction.Comment: 12 pages, 14 figure

Shuttle Ku-band and S-band communications implementation study

Various aspects of the shuttle orbiter S-band network communication system, the S-band payload communication system, and the Ku-band communication system are considered. A method is proposed for obtaining more accurate S-band antenna patterns of the actual shuttle orbiter vehicle during flight because the preliminary antenna patterns using mock-ups are not realistic that they do not include the effects of additional appendages such as wings and tail structures. The Ku-band communication system is discussed especially the TDRS antenna pointing accuracy with respect to the orbiter and the modifications required and resulting performance characteristics of the convolutionally encoded high data rate return link to maintain bit synchronizer lock on the ground. The TDRS user constraints on data bit clock jitter and data asymmetry on unbalanced QPSK with noisy phase references are included. The S-band payload communication system study is outlined including the advantages and experimental results of a peak regulator design built and evaluated by Axiomatrix for the bent-pipe link versus the existing RMS-type regulator. The nominal sweep rate for the deep-space transponder of 250 Hz/s, and effects of phase noise on the performance of a communication system are analyzed