More Schooling, Less Youth Crime? : Learning from an Earthquake in Japan

Preprin

Detecting User Engagement in Everyday Conversations

This paper presents a novel application of speech emotion recognition: estimation of the level of conversational engagement between users of a voice communication system. We begin by using machine learning techniques, such as the support vector machine (SVM), to classify users' emotions as expressed in individual utterances. However, this alone fails to model the temporal and interactive aspects of conversational engagement. We therefore propose the use of a multilevel structure based on coupled hidden Markov models (HMM) to estimate engagement levels in continuous natural speech. The first level is comprised of SVM-based classifiers that recognize emotional states, which could be (e.g.) discrete emotion types or arousal/valence levels. A high-level HMM then uses these emotional states as input, estimating users' engagement in conversation by decoding the internal states of the HMM. We report experimental results obtained by applying our algorithms to the LDC Emotional Prosody and CallFriend speech corpora.Comment: 4 pages (A4), 1 figure (EPS

Donating time to charity : working for nothing?

This work was supported by the University of Warwick Economics Department.Peer reviewedPostprin

Identification of causal effects using the 1995 earthquake in Japan : studies of education and health

This thesis aims to identify causal effects using a natural experimental approach. We focus on the Great Hanshin-Awaji Earthquake in midwestern Japan as a source of exogenous variation in the variables of interest. Chapter 1 explores the causal effect of schooling on juvenile delinquency using variation in schooling caused by policy interventions in specific municipalities after the earthquake. Using the instrumental variable estimator to address endogeneity problems arising from simultaneity and unobserved heterogeneity, we find that schooling reduces juvenile delinquency, although some of our estimates have large standard errors and are imprecisely estimated. The results indicate that a one-percentage-point increase in the high school participation rate reduces the number of juvenile arrests by approximately 1.1 per 1,000 youths. 1 Estimates of social benefits show that it is less expensive to reach a target level of social benefits by improving schooling than by strengthening police forces. Chapter 2 studies the causal effect of volunteer work on the mortality of the elderly. After the earthquake, levels of volunteering increased considerably in municipalities hit by the earthquake, while other municipalities did not experience such a sharp increase. This exogenous shift in levels of volunteering is exploited to address the endogeneity problem associated with estimating the effects of volunteering. Specifically, unobserved heterogeneity across municipalities that affects both morality and the level of volunteering, such as the quality of local health care services, may bias estimates on the effect of volunteering. The results indicate that volunteering has no significant effect on mortality amongst people in their 50s and 60s, while it significantly reduces mortality amongst people in their 70s and 80s or older. Evaluated at the mean, the estimate implies that the life of approximately one person aged 80 or older (out of 186 persons) is saved in a given year when the number of volunteers increases by 100 (out of 1,911 persons)

Normal integral bases of Lehmer's cyclic quintic fields

Let $K_n$ be a tamely ramified cyclic quintic field generated by a root of Emma Lehmer's parametric polynomial. We give all normal integral bases for $K_n$ only by the roots of the polynomial, which is a generalization of the work of Lehmer in the case that $n^4+5n^3+15n^2+25n+25$ is prime number, and Spearman-Willliams in the case that $n^4+5n^3+15n^2+25n+25$ is square-free

Speak better, do better? Education and health of migrants in the UK

We are grateful to the editor, Albrecht Glitz, and two anonymous reviewers for comments that helped greatly improve our paper. We also gratefully acknowledge the permission of the Office for National Statistics (ONS) to use the Longitudinal Study, and the help provided by staff of the Centre for Longitudinal Study Information and User Support, which is supported by the ESRC Census of Population Programme (Award Ref: ES/K000365/1). We thank Richard Prothero, and the participants of the EALE/SOLE meeting in Montreal, ESPE conference in Izmir, Applied Economics workshop in Catanzaro, and seminars/workshops at the University of Aberdeen, University of Alicante and CPB Netherlands Bureau for Economic Policy Analysis for discussions that improved this paper. Financial support from the Scottish Institute for Research in Economics and the Carnegie Trust for the Universities of Scotland is also gratefully acknowledged. The authors alone are responsible for the interpretation of the data. This work contains statistical data from the ONS which is Crown Copyright and all statistical results remain Crown Copyright. The use of the ONS Statistics statistical data in this work does not imply the endorsement of the ONS in relation to the interpretation or analysis of the statistical data. This work uses research datasets which may not exactly reproduce National Statistics aggregates.Peer reviewedPostprin

Heavy-quark free energy at finite temperature with 2+1 flavors of improved Wilson quarks in fixed scale approach

The free energy between a static quark and an antiquark is studied by using the color-singlet Polyakov-line correlation at finite temperature. We perform simulations on $32^3 \times 12$, 10, 8, 6, 4 lattices in the high temperature phase with the RG-improved gluon action and 2+1 flavors of the clover-improved Wilson quark action. Since the simulations are based on the fixed scale approach that the temperature can be varied without changing the spatial volume and renormalization factor, it is possible to investigate temperature dependence of the heavy-quark free energy without any adjustment of the overall constant. We find that, the heavy-quark free energies at short distance converge to the heavy-quark potential evaluated from the Wilson-loop operator at zero temperature, in accordance with the expected insensitivity of short distance physics to the temperature. At long distance, the heavy-quark free energies approach to twice the single-quark free energies, implying that the interaction between heavy quarks is screened. The Debye screening mass obtained from the long range behavior of the heavy-quark free energy is compared with results of the thermal perturbation theory and those of $N_f=2$ and $N_f=0$ lattice simulations.Comment: To appear in the proceedigns of 27th International Symposium on Lattice Field Theory (Lattice 2009), Beijing, China, 25-31 July 200

A hierarchy of models related to nanoflows and surface diffusion

In last years a great interest was brought to molecular transport problems at nanoscales, such as surface diffusion or molecular flows in nano or sub-nano-channels. In a series of papers V. D. Borman, S. Y. Krylov, A. V. Prosyanov and J. J. M. Beenakker proposed to use kinetic theory in order to analyze the mechanisms that determine mobility of molecules in nanoscale channels. This approach proved to be remarkably useful to give new insight on these issues, such as density dependence of the diffusion coefficient. In this paper we revisit these works to derive the kinetic and diffusion models introduced by V. D. Borman, S. Y. Krylov, A. V. Prosyanov and J. J. M. Beenakker by using classical tools of kinetic theory such as scaling and systematic asymptotic analysis. Some results are extended to less restrictive hypothesis

Past Actions and Expertise: How States Infer Enemy Intentions

Whether and how a state’s past military (in)actions affect perceptions of its resolve and intentions has been disputed. This dissertation argues that non-experts and experts in governments use enemy past actions differently to infer enemy resolve and intentions. Experts are those who have rich knowledge about enemies (e.g., country specialists and intelligence analysts), whereas non-experts are those who do not (e.g., top policymakers). The theory argues that non-experts are influenced by what psychologists call the “negativity bias,” which compels them to pay more attention to negative information than positive information concerning enemies. On the other hand, building on experimental findings that professional skills mitigate biases, the theory argues experts’ professional knowledge about enemies mitigates the negativity bias. As a result, faced with the same set of information concerning enemies, including their past actions, these two groups reach different conclusions about their resolve and intentions. Utilizing primary sources extensively, this dissertation shows the theory’s plausibility by examining how US officials assessed their enemies’ resolve and intentions in three cases from the Cold War