Minimum Wage and Compliance in a Model of Search On-the-Job

minimum wages, compliance, job search, wage growth

From quantum pulse gate to quantum pulse shaper -- enigneered frequency conversion in nonlinear optical waveguides

Full control over the spatio-temporal structure of quantum states of light is an important goal in quantum optics, to generate for instance single-mode quantum pulses or to encode information on multiple modes, enhancing channel capacities. Quantum light pulses feature an inherent, rich spectral broadband-mode structure. In recent years, exploring the use of integrated optics as well as source-engineering has led to a deep understanding of the pulse-mode structure of guided quantum states of light. In addition, several groups have started to investigate the manipulation of quantum states by means of single-photon frequency conversion. In this paper we explore new routes towards complete control of the inherent pulse-modes of ultrafast pulsed quantum states by employing specifically designed nonlinear waveguides with adapted dispersion properties. Starting from our recently proposed quantum pulse gate (QPG) we further generalize the concept of spatio-spectral engineering for arbitrary \chitwo-based quantum processes. We analyse the sum-frequency generation based QPG and introduce the difference-frequency generation based quantum pulse shaper (QPS). Together, these versatile and robust integrated optics devices allow for arbitrary manipulations of the pulse-mode structure of ultrafast pulsed quantum states. The QPG can be utilized to select an arbitrary pulse mode from a multimode input state, whereas the QPS enables the generation of specific pulse modes from an input wavepacket with Gaussian-shaped spectrum.Comment: 21 pages, 9 figure

Determination of optimum voltages of ion focusing devices using computer techniques

Electric potentials for two dimensional cross sections of ion focusing devices used in a mass spectrometer are calculated via a series of computer programs designed to compute potentials between areas of fixed voltages. Ion trajectories within these devices may be determined by computer and a histogram obtained which plots ion density against ion position along a plate of the focusing device. For each lens system, a plate voltage may be changed, the electric potentials recalculated, and a new histogram calculated in order to determine if the new voltage configuration has increased the device's efficiency. This process may be repeated until the optimum voltage values have been found for maximum particle transmission in each focusing device

A bright, pulsed two-mode squeezer

We report the realization of a bright ultrafast two-mode squeezer based on type II parametric downconversion (PDC) in periodically poled $\mathrm{KTiOPO_4}$ (PP-KTP) waveguides. It produces a pulsed two-mode squeezed vacuum state: a photon-number entangled pair of truly single-mode pulses or, in terms of continuous variables quantum optics, a pulsed, single mode Einstein-Podolsky-Rosen (EPR) state in the telecom regime. We prove the single mode character of our source by measuring its $g^{(2)}$ correlation function and demonstrate a mean photon number of up to 2.5 per pulse, equivalent to 11dB of two-mode squeezing.Comment: 4 pages, 3 figure

Determinants of VMT in Urban Areas:A Panel Study of 87 U.S. Urban Areas 1982-2009

This paper uses econometric techniques to examine the determinants of vehicle miles traveled (VMT) in a panel study using data from a cross section of 87 U.S. urban areas over the period 1982-2009. We use standard OLS regression as well as two-stage least squares techniques to examine the impact of factors such as urban density, lane-miles, per capita income, real fuel cost, transit mileage, and various industry mix variables on per capita VMT. We use a distributed lag model to estimate long-run elasticities and find that the long-run price elasticity of demand for per capita VMT is approximately five times larger than in the short run. Preliminary empirical results show the per capita demand for VMT in urban areas is positively and significantly impacted by lane miles, personal income, and the percent of employment in the construction and public sectors. Fuel price and transit use and the percent of employment in manufacturing, retail, and wholesale sectors are all found to be statistically significant and negatively related to VMT per capita. After correcting for endogeneity, urban population density exerts a negative, but not always statistically significant, impact on per capita VMT. Finally, per capita VMT is found to differ significantly by geographic region, being higher the more western and the larger the population size of an urban area

Reduced leakage current in Josephson tunnel junctions with codeposited barriers

Josephson junctions were fabricated using two different methods of barrier formation. The trilayers employed were Nb/Al-AlOx/Nb on sapphire, where the first two layers were epitaxial. The oxide barrier was formed either by exposing the Al surface to O2 or by codepositing Al in an O2 background. The codeposition process yielded junctions that showed the theoretically predicted subgap current and no measurable shunt conductance. In contrast, devices with barriers formed by thermal oxidation showed a small shunt conductance in addition to the predicted subgap current.Comment: 3 pages, 4 figure

Teaching the Inevitable: Embracing a Pedagogy of Failure

Failure is often taken as a given in higher education, as an inevitable part of learning new things. Yet, it remains a part of learning that students tend to fear, and faculty tend to neglect. As faculty, we do not always strategize with or leverage our students’ struggles and failures for improved learning. Instead, we hope that students learn from their mistakes and study harder or try harder the next time, because moving on with material in class is necessary to meet learning objectives. In this article, we outline several strategies for using failure advantageously for promoting student growth and learning, and to minimize the stigma of struggle in academia. We make concrete suggestions and outline strategies and resources for faculty to incorporate a “pedagogy of failure” into their work with students and we describe structural barriers to using failure strategically in higher education. Click here to read the corresponding ISSOTL blog post

Shrub and tree growth in southeast Tibet: new information for dendroclimatology

Abstract HKT-ISTP 2013 B

Identification of barely visible impact damages on a stiffened composite panel with a probability-based approach

A probability-based damage detection algorithm has been implemented in order to identify barely visible impact damages in two composite stiffened panels by means of Acousto Ultrasonics (AU). A modification of RAPID (reconstruction algorithm for probabilistic inspection of defects) has been implemented to adapt the algorithm to the current structures and transducer networks. An improvement of 40% in the localization accuracy is obtained with the new algorith