A Cause and Effect Analysis of Motion Trajectories for Modeling Actions

An action is typically composed of different parts of the object moving in particular sequences. The presence of different motions (represented as a 1D histogram) has been used in the traditional bag-of-words (BoW) approach for recognizing actions. However the interactions among the motions also form a crucial part of an action. Different object-parts have varying degrees of interactions with the other parts during an action cycle. It is these interactions we want to quantify in order to bring in additional information about the actions. In this paper we propose a causality based approach for quantifying the interactions to aid action classification. Granger causality is used to compute the cause and effect relationships for pairs of motion trajectories of a video. A 2D histogram descriptor for the video is constructed using these pairwise measures. Our proposed method of obtaining pairwise measures for videos is also applicable for large datasets. We have conducted experiments on challenging action recognition databases such as HMDB51 and UCF50 and shown that our causality descriptor helps in encoding additional information regarding the actions and performs on par with the state-of-the art approaches. Due to the complementary nature, a further increase in performance can be observed by combining our approach with state-of-the-art approaches.

La labor del responsable financiero de una empresa

Duración (en horas): De 31 a 40 horas. Nivel educativo: Grado

Labor Market Assimilation of Recent Immigrants in Spain

Revised: 2006-11.-- Published as an article in: British Journal of Industrial Relations, June 2007, vol. 45, issue 2, pp. 257-284.

Immigrants Responsiveness to Labor Market Conditions

Using data from the Spanish Labor Force Survey (Encuesta de Población Activa) from 1999 through 2004, we explore the role of regional employment opportunities in explaining the increasing immigrant flows of recent years despite the limited internal mobility on the part of natives. Subsequently, we investigate the policy question of whether immigration has helped reduced unemployment rate disparities across Spanish regions by attracting immigrant flows to regions offering better employment opportunities. Our results indicate that immigrants choose to reside in regions with larger employment rates and where their probability of finding a job is higher. In particular, and despite some differences depending on their origin, immigrants appear generally more responsive than their native counterparts to a higher likelihood of informal, self, or indefinite employment. More importantly, insofar the vast majority of immigrants locate in regions characterized by higher employment rates, immigration contributes to greasing the wheels of the Spanish labor market by narrowing regional unemployment rate disparities.

Union Formation and Bargaining Rules in the Labor Market

This paper analyzes union formation in a model of bargaining between a firm and several unions. We address two questions: first, the optimal configuration of unions (their number and size) and, second, the impact of the bargaining pattern (simultaneous or sequential). For workers, grouping into several unions works as a price discrimination device which, at the same time, decreases their market power. The analysis shows that optimal union configuration depends on the rules that regulate the bargaining process (monopoly union, Nash bargaining or right to manage).

Optimal Fiscal Policy with Rationing in the Labor Market

Published as an article in: Topics in Macroeconomics, 2005, vol. 5, issue 1, article 17.

Copia de una Carta de Alberto Onaindia a su hermano Domingo en la que el primero informa al último de la labor espiritual realizada en la Prisión del Carmelo de Begoña entre el 25 de julio de 1937 hasta abril de 1938.

Fecha: s.f. (>1970 copia) / Unidad de instalación: Carpeta 45 - Expediente 2-17 / Nº de pág.: 2 (mecanografiadas)

Skill premium effects on fertility and female labor force supply

Published as an article in: Journal of Population Economics, 2004, vol. 17, issue 1, pages 1-16.

An Estimated New-Keynesian Model with Unemployment as Excess Supply of Labor

Wage stickiness is incorporated to a New-Keynesian model with variable capital to drive endogenous unemployment uctuations de ned as the log di¤erence between aggregate labor supply and aggregate labor demand. We estimated such model using Bayesian econometric techniques and quarterly U.S. data. The second-moment statistics of the unemployment rate in the model give a good t to those observed in U.S. data. Our results also show that wage-push shocks, demand shifts and monetary policy shocks are the three major determinants of unemployment fl uctuations. Compared to an estimated New-Keynesian model without unemployment (Smets and Wouters, 2007): wage stickiness is higher, labor supply elasticity is lower, the slope of the New-Keynesian Phillips curve is flatter, and the importance of technology innovations on output variability increases.

Aspects of the oyster season in Maryland: Involving labor conflicts detrimental to both seafood and cannery industries, with special reference to the latter

For fully three decades there has been an almost steady decline in Maryland's oyster production... are alarmed for its future. Reasons for decline, data supplied,importance of brood oysters and clutch replenishment. Problems of warm weather and bacterial activity as well as tongs grinding the bottom. Conflicts in canning of early season oysters and late season crops like tomatoes. (PDF contains 16 pages)

La labor del equipo TRACE: metodología descriptiva de la censura en traducción

Raquel Merino Álvarez, José Miguel Santamaría, Eterio Pajares (eds.)

Nonexistence of looping trajectories in hydromagnetic waves of finite amplitude. Breaking of waves in a cold collision-free plasma in a magnetic field. On stabilities of periodic waves in a cold collision-free plasma in a magnetic field.

This dissertation consists of three parts. In Part I, it is shown that looping trajectories cannot exist in finite amplitude stationary hydromagnetic waves propagating across a magnetic field in a quasi-neutral cold collision-free plasma. In Part II, time-dependent solutions in series expansion are presented for the magnetic piston problem, which describes waves propagating into a quasi-neutral cold collision-free plasma, ensuing from magnetic disturbances on the boundary of the plasma. The expansion is equivalent to Picard's successive approximations. It is then shown that orbit crossings of plasma particles occur on the boundary for strong disturbances and inside the plasma for weak disturbances. In Part III, the existence of periodic waves propagating at an arbitrary angle to the magnetic field in a plasma is demonstrated by Stokes expansions in amplitude. Then stability analysis is made for such periodic waves with respect to side-band frequency disturbances. It is shown that waves of slow mode are unstable whereas waves of fast mode are stable if the frequency is below the cutoff frequency. The cutoff frequency depends on the propagation angle. For longitudinal propagation the cutoff frequency is equal to one-fourth of the electron's gyrofrequency. For transverse propagation the cutoff frequency is so high that waves of all frequencies are stable.

Alternative trajectories for decarbonizing urban transportation

4 p.