The interaction of firing costs and on-the-job search : an application of a search theoretic model to the Spanish labour market

En España el desempleo ha constituido un problema estructural importante durante los ultimos veinte años. El autor argumenta que la interaccion de los costes de despido y los flujos de empleo a empleo, junto con los cambios en los subsidios por desempleo, podrian proporcionar una explicacion del aumento en el desempleo de equilibrio desde 1984. (rb) (ad

ABC: A Simple Explicit Congestion Controller for Wireless Networks

We propose Accel-Brake Control (ABC), a simple and deployable explicit congestion control protocol for network paths with time-varying wireless links. ABC routers mark each packet with an "accelerate" or "brake", which causes senders to slightly increase or decrease their congestion windows. Routers use this feedback to quickly guide senders towards a desired target rate. ABC requires no changes to header formats or user devices, but achieves better performance than XCP. ABC is also incrementally deployable; it operates correctly when the bottleneck is a non-ABC router, and can coexist with non-ABC traffic sharing the same bottleneck link. We evaluate ABC using a Wi-Fi implementation and trace-driven emulation of cellular links. ABC achieves 30-40% higher throughput than Cubic+Codel for similar delays, and 2.2X lower delays than BBR on a Wi-Fi path. On cellular network paths, ABC achieves 50% higher throughput than Cubic+Codel

Unemployment and growth dynamics: Theory and OECD evidence.

We study unemployment and growth dynamics. A search theoretic approach, augmented by exogenous and endogenous growth considerations, is used. We apply a variety of macro-econometric tools, across OECD countries, namely: structural vector autoregression (SVAR) analysis; simulations; frequency domain analysis and panel data regression analysis, to test out a variety of hypotheses drawn from the theoretical literature. First, we look at unemployment dynamics, using a search model and an SVAR methodology, and discover that the European Community and the US have faced similar shocks, mainly aggregate ones, but have reacted very differently. The exception is Spain, where most of the unemployment dynamics have been driven by reallocation. Overall, this implies that EEC economies might be 'dynamically sclerotic' when compared to the US, though simulations do not confirm this result. Next, we re-examine the link between growth and unemployment. Using: frequency domain analysis, panel data regression analysis and looking at cross correlations, we find that the interactions are weak, with at best a marginally significant negative effect of growth on unemployment. This is consistent with theories that predict capitalization effects dominate creative destruction, in the effect of growth on unemployment. It is not consistent with theories that imply a strong effect of unemployment on growth, through: loss of skills; learning by doing; cleansing effects and savings effects. Even when the capitalization effect is significant, it is not very large. A 1% increase in steady state growth would only reduce equilibrium unemployment by 1%. Finally, we look at the links between growth, R&D and job flows, as an alternative way to isolate creative destruction effects. We find that creative destruction mechanisms are only important for US, i.e. for a country on the technological frontier

Crystal growth and properties of the non-centrosymmetric superconductor, Ru7B3

We describe the crystal growth of high quality single crystals of the non-centrosymmetric superconductor, Ru7B3 by the floating zone technique, using an optical furnace equipped with xenon arc lamps. The crystals obtained are large and suitable for detailed measurements, and have been examined using x-ray Laue patterns. The superconducting properties of the crystals obtained have been investigated by magnetisation and resistivity measurements. Crystals have also been grown starting with enriched 11B isotope, making them suitable for neutron scattering experiments.Comment: 4 pages, 5 figures. Accepted for publication in Journal of Crystal Growt

MadEye: Boosting Live Video Analytics Accuracy with Adaptive Camera Configurations

Camera orientations (i.e., rotation and zoom) govern the content that a camera captures in a given scene, which in turn heavily influences the accuracy of live video analytics pipelines. However, existing analytics approaches leave this crucial adaptation knob untouched, instead opting to only alter the way that captured images from fixed orientations are encoded, streamed, and analyzed. We present MadEye, a camera-server system that automatically and continually adapts orientations to maximize accuracy for the workload and resource constraints at hand. To realize this using commodity pan-tilt-zoom (PTZ) cameras, MadEye embeds (1) a search algorithm that rapidly explores the massive space of orientations to identify a fruitful subset at each time, and (2) a novel knowledge distillation strategy to efficiently (with only camera resources) select the ones that maximize workload accuracy. Experiments on diverse workloads show that MadEye boosts accuracy by 2.9-25.7% for the same resource usage, or achieves the same accuracy with 2-3.7x lower resource costs.Comment: 19 pages, 16 figure

Evaluation and Comparison of Plasma miRNA-31 in Oral Squamous Cell Carcinoma

Background/Purpose: Oral Squamous cell carcinoma is sixth most common cancer with considerable morbidity and mortality. The microRNAs (miRNAs) are set of short RNAs involved in regulating the expression of protein coding genes. They are up or down-regulated in carcinogenesis and in oral cancer. The miRNA-31 (miR-31) is increased in oral cancer. Objective: To evaluate and compare the expression of miRNA-31 in plasma of Oral squamous cell carcinoma and control subjects. Materials and Methods: Case control study was carried out in 25 cases of oral squamous cell carcinoma subjects and 25 normal control subjects. The level of miRNA-31 in blood plasma was evaluated by miRNA easy kit (quagen) and miRNA-based qRT-PCR. The fold change was observed and compared between OSCC and controls. Results: The plasma level of miRNA-31 was significantly increased in OSCC patients compared to controls (p<0.001). The patients with moderately differentiated, grade 4 OSCC patients showed significant increase in fold change compared to control, well differentiated and grade 3 OSCC (p<0.001). Conclusion: Our results indicate that plasma miR-31 may be used as an adjuvant biomarker the detection of OSCC patient

Generalized Langevin dynamics of a nanoparticle using a finite element approach: Thermostating with correlated noise

A direct numerical simulation (DNS) procedure is employed to study the thermal motion of a nanoparticle in an incompressible Newtonian stationary fluid medium with the generalized Langevin approach. We consider both the Markovian (white noise) and non-Markovian (Ornstein-Uhlenbeck noise and Mittag-Leffler noise) processes. Initial locations of the particle are at various distances from the bounding wall to delineate wall effects. At thermal equilibrium, the numerical results are validated by comparing the calculated translational and rotational temperatures of the particle with those obtained from the equipartition theorem. The nature of the hydrodynamic interactions is verified by comparing the velocity autocorrelation functions and mean square displacements with analytical results. Numerical predictions of wall interactions with the particle in terms of mean square displacements are compared with analytical results. In the non-Markovian Langevin approach, an appropriate choice of colored noise is required to satisfy the power-law decay in the velocity autocorrelation function at long times. The results obtained by using non-Markovian Mittag-Leffler noise simultaneously satisfy the equipartition theorem and the long-time behavior of the hydrodynamic correlations for a range of memory correlation times. The Ornstein-Uhlenbeck process does not provide the appropriate hydrodynamic correlations. Comparing our DNS results to the solution of an one-dimensional generalized Langevin equation, it is observed that where the thermostat adheres to the equipartition theorem, the characteristic memory time in the noise is consistent with the inherent time scale of the memory kernel. The performance of the thermostat with respect to equilibrium and dynamic properties for various noise schemes is discussed

Mahimahi: A Lightweight Toolkit for Reproducible Web Measurement

This demo presents a measurement toolkit, Mahimahi, that records websites and replays them under emulated network conditions. Mahimahi is structured as a set of arbitrarily composable UNIX shells. It includes two shells to record and replay Web pages, RecordShell and ReplayShell, as well as two shells for network emulation, DelayShell and LinkShell. In addition, Mahimahi includes a corpus of recorded websites along with benchmark results and link traces (https://github.com/ravinet/sites). Mahimahi improves on prior record-and-replay frameworks in three ways. First, it preserves the multi-origin nature of Web pages, present in approximately 98% of the Alexa U.S. Top 500, when replaying. Second, Mahimahi isolates its own network traffic, allowing multiple instances to run concurrently with no impact on the host machine and collected measurements. Finally, Mahimahi is not inherently tied to browsers and can be used to evaluate many different applications. A demo of Mahimahi recording and replaying a Web page over an emulated link can be found at http://youtu.be/vytwDKBA-8s. The source code and instructions to use Mahimahi are available at http://mahimahi.mit.edu/