Sequential Monte Carlo for rare event estimation

This paper discusses a novel strategy for simulating rare events and an associated Monte Carlo estimation of tail probabilities. Our method uses a system of interacting particles and exploits a Feynman-Kac representation of that system to analyze their fluctuations. Our precise analysis of the variance of a standard multilevel splitting algorithm reveals an opportunity for improvement. This leads to a novel method that relies on adaptive levels and produces, in the limit of an idealized version of the algorithm, estimates with optimal variance. The motivation for this theoretical work comes from problems occurring in watermarking and fingerprinting of digital contents, which represents a new field of applications of rare event simulation techniques. Some numerical results show performance close to the idealized version of our technique for these practical applications.     

Protective factors and risk factors of being a victim of couple violence in women and men / Factores de riesgo y protección de ser víctima de violencia en la pareja en mujeres y hombres

The aim of this study is to determine the risk factors and protective factors of being a victim of couple violence, considering cultural conventions, coping, social support, external attribution and violence in childhood. A non-probabilistic sample of 223 women and 177 men was used. The risk factors in the sample as a whole were being male, the coping strategy of accommodation, violence in childhood and external attribution, while the protective factors were partner support and an active coping style. The study concludes with suggestions for interventions and research.     

Adaptive and Maladaptive Coping Strategies in Adult Pathological Gamblers and Their Mediating Role with Anxious-Depressive Symptomatology

Coping plays a central role in the appearance and persistence of pathological gambling. Anxious and depressive symptomatology also influence pathological gambling and are related to coping. This study aimed to analyze pathological gamblers’ coping strategies and styles, as well as associated anxious and depressive symptomatology. The study sample included 167 male pathological gamblers (mean age = 39.29 years) and 107 non-gamblers (mean age = 33.43 years). Measures of gambling, coping, and anxious and depressive symptomatology were used. Results showed that pathological gamblers’ scored higher in all the maladaptive coping strategies, problem- and emotion-focused disengagement, and disengagement subscales. These subscales also correlated with pathological gambling, and anxious and depressive symptomatology. Pathological gamblers also scored higher in emotional expression and emotion-focused engagement, with no differences in the rest of the adaptive coping strategies. Coping was also found to predict pathological gambling and anxious and depressive symptomatology. It was found that coping mediated the relationship between pathological gambling and anxious symptomatology when controlling for the effect of age. Specifically, social withdrawal and disengagement stood out as mediators. These results provide practical information for use in clinical settings with people diagnosed with pathological gambling.     

Emotional Transactions in the Paris Subway: Combining Naturalistic Videotaping,Objective Facial Coding and Sequential Analysis in the Study of Nonverbal Emotional Behavior

We report on what, to our knowledge, represents the first study of nonverbal emotional behavior in crowded public places combining naturalistic videotaping of situated activity, objective coding of facial movement, and sequential analysis of behavior. In the first part of the study we argue that passengers do not lose emotional sensitivity to physical contact as density (passengers per square meter) increases, which indicates that physical contact is experienced as a territorial intrusion regardless of crowdedness. In the second part of the study, we suggest that passengers resolve the emotions due to intrusive physical contacts through two interactional strategies involving facial movements usually interpreted as “expressions of emotions.” Since proxemic violations seem to represent a pervasive emotion elicitor, the protocol can be extended to other means of transportation and replicated in other locations. We conclude that the methodology provides an effective tool for theory-building in the study of nonverbal emotional behavior.     

Reporting Errors in Siblings’ Survival Histories and Their Impact on Adult Mortality Estimates: Results From a Record Linkage Study in Senegal

Estimates of adult mortality in countries with limited vital registration (e.g., sub-Saharan Africa) are often derived from information about the survival of a respondent’s siblings. We evaluated the completeness and accuracy of such data through a record linkage study conducted in Bandafassi, located in southeastern Senegal. We linked at the individual level retrospective siblings’ survival histories (SSH) reported by female respondents (n = 268) to prospective mortality data and genealogies collected through a health and demographic surveillance system (HDSS). Respondents often reported inaccurate lists of siblings. Additions to these lists were uncommon, but omissions were frequent: respondents omitted 3.8 % of their live sisters, 9.1 % of their deceased sisters, and 16.6 % of their sisters who had migrated out of the DSS area. Respondents underestimated the age at death of the siblings they reported during the interview, particularly among siblings who had died at older ages (≥45 years). Restricting SSH data to person-years and events having occurred during a recent reference period reduced list errors but not age and date errors. Overall, SSH data led to a 20 % underestimate of ₄₅ q ₁₅ relative to HDSS data. Our study suggests new quality improvement strategies for SSH data and demonstrates the potential use of HDSS data for the validation of “unconventional” demographic techniques.     

Estimating urban lawn cover in space and time: Case studies in three Swedish cities

Lawns are considered monocultures and lesser contributors to sustainability than diverse nature but are still a dominating green area feature and an important cultural phenomenon in cities. Lawns have esthetical values, provide playground, are potential habitat for species, contribute to carbon sequestration and water infiltration, but also increase pesticides, fertilization, are monocultures and costly to manage at the same time. To evaluate the potential impact of lawns, whether positive or negative, it is of interest to estimate the total lawn cover in cities and its change over time. This is not a straightforward process, e.g., because many lawns are small and covered by trees. In this study we review the existing literature of lawn cover in cities and the different methodologies used for cover estimation. We found both pros and cons with NDVI and LiDAR data as well as manually interpreted aerial photos. The total cover of lawns in three case study cities was estimated to 22.5%. By extrapolating these percentages to all Swedish cities lawn cover was estimated to 2589 km² (0.6% of the terrestrial surface). The approximated total municipal management cost of lawns in all Swedish cities was 910,000,000 USD/ year. During 50 years lawn area almost doubled in relative cover and 56% of them were continuously managed. Since lawns constitute large parts of the urban greenery and are costly to manage it is highly relevant to consider their social, ecological and cultural value compared to alternatives, e.g., meadows with less intensive management.     

Ethical living: relinking ethics and consumption through care in Chile and Brazil

Mainstream conceptualizations of ‘ethical consumption’ equate the notion with conscious, individual, market‐mediated choices motivated by ethical or political aims that transcend ordinary concerns. Drawing on recent sociology and anthropology of consumption literature on the links between ordinary ethics and ethical consumption, this article discusses some of the limitations of this conceptualization. Using data from 32 focus groups conducted in Chile and Brazil, we propose a conceptualization of ethical consumption that does not centre on individual, market‐mediated choices but understands it at the level of practical outcomes, which we refer to as different forms of ‘ethical living’. To do that, we argue, we need to depart from the deontological understanding of ethics that underpins mainstream approaches to ethical consumption and adopt a more consequentialist view focusing on ethical outcomes. We develop these points through describing one particular ordinary moral regime that seemed to be predominant in participants’ accounts of ethics and consumption in both Chile and Brazil: one that links consumption and ethics through care. We show that the moral regime of care leads to ‘ethical outcomes’, such as energy saving or limiting overconsumption, yet contrary to the mainstream view of ethical consumption emphasizing politicized choice expressed through markets, these result from following ordinary ethics, often through routines of practices.     

‘Growing Old’ in Shelters and ‘On the Street’: Experiences of Older Homeless People

Homelessness among older people in Canada is both a growing concern, and an emerging field of study. This article reports thematic results of qualitative interviews with 40 people aged 46 to 75, carried out as part of a mixed-methods study of older people who are homeless in Montreal, Quebec, Canada. Our participants included people with histories of homelessness (n = 14) and persons new to homelessness in later life (n = 26). Interviews focused on experiences at the intersections of aging and homelessness including social relationships, the challenges of living on the streets and in shelters in later life, and the future. This article outlines the 5 main themes that capture the experience of homelessness for our participants: age exacerbates worries; exclusion and isolation; managing significant challenges; shifting needs and realities; and resilience, strength, and hope. Together, these findings underscore the need for specific programs geared to the unique needs of older people who are homeless.     

Multinomial Selection in the Presence of Infinite Alternatives

We propose a new procedure for the multinomial selection problem to solve a real problem of any modern Air Force: the elaboration of better air-to-air tactics for Beyond Visual Range air-to-air combat that maximize its aircraft survival probability H(θ, ω), as well as enemy aircraft downing probability G(θ, ω). In this study, using a low-resolution simulator with generic parameters for the aircraft and missiles, we could increase an average success rate of 16.69% and 16.23% for H(θ, ω) and G(θ, ω), respectively, to an average success rate of 76.85% and 79.30%. We can assure with low probability of being wrong that the selected tactic has greater probability of yielding greater success rates in both H(θ, ω) and G(θ, ω) than any simulated tactic.