Reducing streak film data via electronic cross correlator

Continuous /nonframing/ motion picture projector, two photocells, a cross-correlator, and a ground glass screen where the photocells intercept the stream image determine the time delay between successive streak images. Velocities corresponding to the streaks are determined from the delay together with the distance separating the photocells

The incidence and intensity of employer-provided training

This paper examines the provision of training by employers and the participation in training by employees, conditional on employers´ training provision. Together these two dimensions of training determine its overall distribution in the workforce. The factors which affect employer training provision and employee training participation are considered simultaneously within an empirical model using data drawn primarily from the 2001 Employers Skill Survey. The results are consistent with high fixed costs but constant marginal costs of training provision, while also supporting many of the predictions regarding the relationship between training and workforce skills, skill-shortages, workplace and local labour market characteristics

Part time employment and happiness: A cross-country analysis

The relationship between part time employment and job satisfaction is analysed for mothers in Germany, Denmark, the Netherlands, Finland, France, Spain and the UK. The impact of working part time on subjective life satisfaction and mental well-being is additionally analysed for British mothers. Cultural traditions concerning women´s role in society, and institutional differences between the countries are exploited. Results indicate that poor quality jobs can diminish any positive well-being repercussions of part time employment. The results additionally suggest that part time mothers in the UK experience higher levels of job satisfaction but not of overall life satisfaction as compared to their full time counterparts

The impact of distance to nearest education institution on the post-compulsory education participation decision

This paper uses data sources with the unique capacity to measure distances between home addresses and education institutions, to investigate, for the first time, the effect that such distance has on an individual´s post–compulsory education participation decision. The results show that there is no overall net effect. However, when attention is focussed on young people who are on the margin of participating in post–compulsory education (according to their prior attainment and family background) and when post–compulsory education is distinguished by whether it leads to academic or vocational qualifications, then greater distance to nearest education institution is seen to have a significant impact on the decision to continue in full–time post–compulsory education. This finding has relevance for education participation in rural areas relative to urban areas

Fears and realisations of employment insecurity

We investigate the validity of subjective data expectations of job loss and on the probability of re-employment consequent on job loss, by examining associations between expectations and realisations. We find that subjective expectations data reveal private information about subsequent job loss, the expectations data perform better with numerical descriptors than with ordinal verbal descriptors. On average, employees overestimate the chance of losing their job; while they underestimate the difficulty of finding another job as good as the currently-held one. We recommend that survey items on employment insecurity should be explicit about each risk investigation, and utilise a cardinal probability scale with discrete numerical descriptors

Ignorance is Almost Bliss: Near-Optimal Stochastic Matching With Few Queries

The stochastic matching problem deals with finding a maximum matching in a graph whose edges are unknown but can be accessed via queries. This is a special case of stochastic $k$-set packing, where the problem is to find a maximum packing of sets, each of which exists with some probability. In this paper, we provide edge and set query algorithms for these two problems, respectively, that provably achieve some fraction of the omniscient optimal solution. Our main theoretical result for the stochastic matching (i.e., $2$-set packing) problem is the design of an \emph{adaptive} algorithm that queries only a constant number of edges per vertex and achieves a $(1-\epsilon)$ fraction of the omniscient optimal solution, for an arbitrarily small $\epsilon>0$. Moreover, this adaptive algorithm performs the queries in only a constant number of rounds. We complement this result with a \emph{non-adaptive} (i.e., one round of queries) algorithm that achieves a $(0.5 - \epsilon)$ fraction of the omniscient optimum. We also extend both our results to stochastic $k$-set packing by designing an adaptive algorithm that achieves a $(\frac{2}{k} - \epsilon)$ fraction of the omniscient optimal solution, again with only $O(1)$ queries per element. This guarantee is close to the best known polynomial-time approximation ratio of $\frac{3}{k+1} -\epsilon$ for the \emph{deterministic} $k$-set packing problem [Furer and Yu, 2013] We empirically explore the application of (adaptations of) these algorithms to the kidney exchange problem, where patients with end-stage renal failure swap willing but incompatible donors. We show on both generated data and on real data from the first 169 match runs of the UNOS nationwide kidney exchange that even a very small number of non-adaptive edge queries per vertex results in large gains in expected successful matches

Gambling and the use of credit: an individual and household level analysis

We explore the relationship between gambling and other forms of risk-taking behaviour, i.e. exposure to debt and the use of credit, at the individual and household level using representative pooled cross-section data drawn from the UK Expenditure and Food Surveys (EFS), 2001 to 2007. Gambling and the use of credit are shown to be positively correlated at the household level. While both the incidence and amount of gambling vary according to household income, the positive association between gambling and the use of credit is remarkably stable across household income. In addition to our household level analysis, we also explore the prevalence of intra-household gambling, which has attracted relatively limited attention in the existing literature. It is apparent that there is strong intra-household correlation in both gambling activity and in the use of credit, with somewhat stronger relationships in lower income households

Balancing the Tradeoff between Profit and Fairness in Rideshare Platforms During High-Demand Hours

Rideshare platforms, when assigning requests to drivers, tend to maximize profit for the system and/or minimize waiting time for riders. Such platforms can exacerbate biases that drivers may have over certain types of requests. We consider the case of peak hours when the demand for rides is more than the supply of drivers. Drivers are well aware of their advantage during the peak hours and can choose to be selective about which rides to accept. Moreover, if in such a scenario, the assignment of requests to drivers (by the platform) is made only to maximize profit and/or minimize wait time for riders, requests of a certain type (e.g. from a non-popular pickup location, or to a non-popular drop-off location) might never be assigned to a driver. Such a system can be highly unfair to riders. However, increasing fairness might come at a cost of the overall profit made by the rideshare platform. To balance these conflicting goals, we present a flexible, non-adaptive algorithm, \lpalg, that allows the platform designer to control the profit and fairness of the system via parameters $\alpha$ and $\beta$ respectively. We model the matching problem as an online bipartite matching where the set of drivers is offline and requests arrive online. Upon the arrival of a request, we use \lpalg to assign it to a driver (the driver might then choose to accept or reject it) or reject the request. We formalize the measures of profit and fairness in our setting and show that by using \lpalg, the competitive ratios for profit and fairness measures would be no worse than $\alpha/e$ and $\beta/e$ respectively. Extensive experimental results on both real-world and synthetic datasets confirm the validity of our theoretical lower bounds. Additionally, they show that \lpalg under some choice of $(\alpha, \beta)$ can beat two natural heuristics, Greedy and Uniform, on \emph{both} fairness and profit