A visual-numeric approach to clustering and anomaly detection for trajectory data

This paper proposes a novel application of Visual Assessment of Tendency (VAT)-based hierarchical clustering algorithms (VAT, iVAT, and clusiVAT) for trajectory analysis. We introduce a new clustering based anomaly detection framework named iVAT+ and clusiVAT+ and use it for trajectory anomaly detection. This approach is based on partitioning the VAT-generated Minimum Spanning Tree based on an efficient thresholding scheme. The trajectories are classified as normal or anomalous based on the number of paths in the clusters. On synthetic datasets with fixed and variable numbers of clusters and anomalies, we achieve 98 % classification accuracy. Our two-stage clusiVAT method is applied to 26,039 trajectories of vehicles and pedestrians from a parking lot scene from the real life MIT trajectories dataset. The first stage clusters the trajectories ignoring directionality. The second stage divides the clusters obtained from the first stage by considering trajectory direction. We show that our novel two-stage clusiVAT approach can produce natural and informative trajectory clusters on this real life dataset while finding representative anomalies.

Intimate partner violence perpetrator subtypes and their developmental origins: implications for prevention and intervention

Intimate partner violence (IPV) is a major issue for many Australian families and yet progress towards the development of effective prevention and behaviour change programs has been relatively slow. In this paper, it is proposed that the tendency to treat perpetrators as a homogenous group has hampered progress, and that treatment outcomes can be improved by tailoring treatment responses to a small set of personal and offence-related characteristics. It explores the developmental origins and trajectories of these presentations and identifies some new directions for further research in this area.

Mating success and body condition not related to foraging specializations in male fur seals

Individual specialization is widespread among wild populations. While its fitness consequences are central in predicting the ecological and evolutionary trajectories of populations, they remain poorly understood. Long-term individual foraging specializations occur in male Antarctic (Arctocephalus gazella) and Australian (A. pusillus doriferus) fur seals. Strong selective pressure is expected in these highly dimorphic and polygynous species, raising the question of the fitness payoffs associated with different foraging strategies. We investigated the relationship between individual isotopic niche (a proxy of foraging specialization), body size and condition, and an index of reproductive success (harem size) in territorial males. Individuals varied greatly in their skin and fur isotopic values reflecting a range of foraging strategies within the two populations. However, in both species, isotopic niche was not correlated to body size, condition or mating success (R (2)/ρ < 0.06). Furthermore, no foraging niche was predominant in either species, which would have indicated a substantial long-term fitness benefit of a particular strategy via a higher survival rate. These results suggest that the fitness consequences of a foraging strategy depend not only on the quality of prey and feeding habitat but also on an individual's hunting efficiency and skills.

Michel de Certeau: research writing as an everyday practice

In this chapter, we engage with de Certeau’s neglected onto-epistemology in order to examine research writing practices as everyday practice. First, in a discussion of de Certeau’s characterisation of practice, we tease out three, interrelated ideas: practice as productive; practice as emergent; and the character of the tactical practitioner. We then apply this view of practice to the field of social research and knowledge production, in particular, discussing the strategic, place-making operations that characterise research writing conventions. We do this to raise questions about how the project of social inquiry might be reconceptualised as a mode of operating on the world, and to suggest potential trajectories of a research practice that—moving beyond representational purposes and claims—is openly an advocacy research.

Personality and individual differences in plasticity

In the last few years, investigators have documented individual differences in many different types of behavioral plasticity. Of particular interest are individual differences in the temporal plasticity of personality traits over extended (ontogenetic) periods of time, because of the relevance of these data to models of behavioral development. We discuss recent empirical studies of the temporal consistency of personality over ontogeny, and models that make contrasting predictions about individual differences in the developmental trajectories of behavioral traits. In addition, we consider recent advances in studies of relationships between personality traits and particular types of behavioral plasticity, including statistical methods which facilitate analyses of relationships between personality traits, contextual plasticity, temporal plasticity and intraindividual variability, and empirical tests of predicted relationships between personality traits and other types of behavioral plasticity (flexibility, learning rates). As the field of animal personality and behavioral plasticity moves from a largely descriptive to a predictive phase, we suggest that there is ample room for empirical tests of recent models that predict individual differences in behavioral developmental trajectories, and for the development of new formal models that make strong predictions about relationships between personality traits and specific types of behavioral plasticity.

Prediction of alcohol-related harm from controlled drinking stragegies and alcohol consumption trajectories

Aims To establish predictors of age 21 alcohol-related harm from prior drinking patterns, current levels of alcohol consumption and use of controlled drinking strategies.
Participants One thousand, five hundred and ninety-six students recruited from an initial sample of 3300 during their final year of high school in 1993.
Design Longitudinal follow-up across five waves of data collection.
Setting Post high school in Victoria, Australia.
Measurements Self-administered surveys examining a range of health behaviours, including alcohol consumption patterns and related behaviour.
Findings Drinking behaviours at age 21 were found to be strongly predicted by drinking trajectories established through the transition from high school. Multivariate regression analysis revealed that alcohol-related harms at age 21 were reduced where current levels of alcohol use fell within limits recommended in Australian national guidelines. After controlling for this effect it was found that the range of strategies employed by participants to control alcohol use maintained a small protective influence. Post-high-school drinking trajectories continued to demonstrate a significant effect after controlling for current behaviours. Findings revealed that over one quarter of males and females drank alcohol, but on a less-than-weekly basis. This pattern of alcohol use demonstrated considerable stability through the post-school transition and was associated with a low level of subsequent harm at age 21.
Conclusions Future research should investigate whether encouraging more Australian adolescents to drink alcohol on a less-than-weekly basis may be a practical intervention target for reducing alcohol-related harms.

Prediction of alcohol-related harm from controlled drinking strategies and alcohol consumption trajectories

Aims To establish predictors of age 21 alcohol-related harm from prior drinking patterns, current levels of alcohol consumption and use of controlled drinking strategies.

Participants One thousand, five hundred and ninety-six students recruited from an initial sample of 3300 during their final year of high school in 1993.

Design Longitudinal follow-up across five waves of data collection.

Setting Post high school in Victoria, Australia.

Measurements Self-administered surveys examining a range of health behaviours, including alcohol consumption patterns and related behaviour.

Findings Drinking behaviours at age 21 were found to be strongly predicted by drinking trajectories established through the transition from high school. Multivariate regression analysis revealed that alcohol-related harms at age 21 were reduced where current levels of alcohol use fell within limits recommended in Australian national guidelines. After controlling for this effect it was found that the range of strategies employed by participants to control alcohol use maintained a small protective influence. Post-high-school drinking trajectories continued to demonstrate a significant effect after controlling for current behaviours. Findings revealed that over one quarter of males and females drank alcohol, but on a less-than-weekly basis. This pattern of alcohol use demonstrated considerable stability through the post-school transition and was associated with a low level of subsequent harm at age 21.

Conclusions Future research should investigate whether encouraging more Australian adolescents to drink alcohol on a less-than-weekly basis may be a practical intervention target for reducing alcohol-related harms.

Psychosocial precursors and correlates of differing internalizing trajectories from 3 to 15 years

Psychosocial precursors and correlates of parent-reported internalizing behavior trajectories across the age span of 3–15 years were explored using a community-based cohort of Australian children. Six internalizing trajectories had previously been identified for both girls (N = 810) and boys (N = 874) in this sample, comprising stable low, high, decreasing, and increasing pathways. Infancy and toddler temperamental traits (inhibition/shyness, irritability), behavior problems, and parent–child relationship difficulties constituted significant risks for subsequent problematic internalizing profiles. Several gender-specific trends were evident, with temperamental reactivity and shyness, less optimal parenting, and peer difficulties more salient for girls on increasing trajectories whereas externalizing problems were more prominent among boys on increasing trajectories. Factors associated with recovery from elevated symptoms included higher levels of social competence, better parent and peer relations, and more positive school adjustment. Findings suggest that individual characteristics and relationship experiences may be involved in the development and course of internalizing problems.

Policy trajectories : treading the discursive path of policy analysis

This paper is concerned with theorising the nature of policy and its production. It takes as its starting point the work of Stephen Ball,1 particularly his writings within the pages of this journal (13(2), 1993)—later reprinted as Chapter 2 in Education Reform (1994a)—as well as his earlier writings in Politics and Policy Making in Education (1990) and Reforming Education and Changing Schools (Bowe, Ball & Gold, 1992). More broadly, the paper is located within a 'new' sociological interest in education policy often referred to as 'policy sociology'2 (Payne, Dingwall, Payne & Carter, 1981; Ozga, 1987, Ball, 1990; Bowe, Ball & Gold, 1992); a concern that is 'rooted in the social science tradition, historically informed and drawing on qualitative and illuminative techniques' (Ozga, 1987, p. 144) and 'united by the conviction that "things", especially policy discourse, must be pulled apart' (Troyna, 1994, p. 71) to determine whose interests they serve.

Precursors and correlates of anxiety trajectories from late childhood to late adolescence

The present research employed a prospective, multi-informant design to examine precursors and correlates of differing anxiety profiles from late childhood to late adolescence. The sample consisted of 626 boys and 667 girls who are participants in the Australian Temperament Project, a large, longitudinal, community-based study that has followed young people's psychosocial adjustment from infancy to adulthood. The present research analyzes data collected from the first 12 waves of data, from 4–8 months to 17 years. Parents, primary school teachers, maternal and child health nurses, and from the age of 11 onward, the young people themselves have provided survey data. Trajectory analyses revealed three distinct patterns of self-reported anxiety from late childhood to late adolescence, comprising low, moderate, and high (increasing) trajectories, which differed somewhat between boys and girls. A range of parent- and teacher-reported factors was found to be associated with these trajectories, including temperament style, behavior problems, social skills, parenting, negative family events, and peer relationships. Compared with male trajectories, female trajectories were associated with a greater variety of psychosocial variables (including parenting and externalizing problems), which may partially account for the higher prevalence of anxiety in adolescent girls compared with boys. Findings shed light on gender-specific pathways to anxiety and the need for comprehensive, integrative approaches to intervention and prevention programs.

Ontogenetic development of migration : Lagrangian drift trajectories suggest a new paradigm for sea turtles

Long distance migration occurs in a wide variety of taxa including birds, insects, fishes, mammals and reptiles. Here, we provide evidence for a new paradigm for the determinants of migration destination. As adults, sea turtles show fidelity to their natal nesting areas and then at the end of the breeding season may migrate to distant foraging sites. For a major rookery in the Mediterranean, we simulated hatchling drift by releasing 288 000 numerical particles in an area close to the nesting beaches. We show that the pattern of adult dispersion from the breeding area reflects the extent of passive dispersion that would be experienced by hatchlings. Hence, the prevailing oceanography around nesting areas may be crucial to the selection of foraging sites used by adult sea turtles. This environmental forcing may allow the rapid evolution of new migration destinations if ocean currents alter with climate change.

Longitudinal predictors of domestic violence perpetration and victimization: a systematic review

Domestic violence (DV) is a serious and complex social issue which is associated with significant costs to both those individuals who are directly affected and the wider community. Preventative approaches with vulnerable population groups represent an important component of any integrated response to DV and should be informed by an understanding of those factors that influence violence developmentally. This paper reports the findings of a systematic review of longitudinal studies that have prospectively investigated childhood and/or adolescent predictors of DV perpetration and/or victimization among adult men and women in intimate relationships. We identified 25 original studies that met the inclusion criteria, all of which investigated predictors of domestic physical abuse. Few studies prospectively examined psychological, sexual and verbal abuse. Child and adolescent abuse, family of origin risks, child and adolescent behavioral problems, adolescent peer risks, and sociodemographic risks were all identified as significant predictors of DV perpetration and victimization. It is concluded that early childhood and adolescent factors are consistent predictors in the development of DV perpetration and victimization and that prevention and early intervention approaches targeting these factors are likely to prove the most effective.

Trajectories and stability of self-reported short sleep duration from adolescence to adulthood

The trajectories and stability of self-reported sleep duration recorded at ages 13, 15, and 23 years on reported sleep duration at age 30 years among 1105 students (55% male) who participated in the Norwegian Longitudinal Health and Behaviour Study were examined. Questionnaire data were used to obtain demographic and sleep variables. Dichotomised short sleep duration was based on normative values and set as ≤8.5 h (age 13 years), ≤8 h (age 15 years) and ≤7 h (ages 23 and 30 years). Results indicated a significant overall reduction in total sleep duration (h per night) across age groups. Sleep duration (continuous) at age 15 and 23 years (whole group) was moderately but positively correlated with sleep duration at age 30 years (P < 0.01). When split by sex, at age 15 years, this association was present among females only (P < 0.01); however, at age 23 years, this association was present in both male and females (both P < 0.001). Categorical short sleep at age 23 years (whole group) was associated with short sleep at age 30 years (unadjusted odds ratio = 3.67, 95% confidence interval 2.36-5.69). Following sex stratification, this effect was significant for both males (unadjusted odds ratio = 3.77, 95% confidence interval: 2.22-6.42) and females (unadjusted odds ratio = 2.71, 95% confidence interval: 1.46-5.04). No associations were noted for categorical short sleep at ages 13 or 15 years, and subsequent short sleep at 30 years. Habitual short sleep duration during middle adulthood is not sustained from the time of early adolescence. Rather, these trends appear to be formed during early adulthood.

DoSTra: Discovering common behaviors of objects using the duration of staying on each location of trajectories

Since semantic trajectories can discover more semantic meanings of a user's interests without geographic restrictions, research on semantic trajectories has attracted a lot of attentions in recent years. Most existing work discover the similar behavior of moving objects through analysis of their semantic trajectory pattern, that is, sequences of locations. However, this kind of trajectories without considering the duration of staying on a location limits wild applications. For example, Tom and Anne have a common pattern of Home→Restaurant → Company → Restaurant, but they are not similar, since Tom works at Restaurant, sends snack to someone at Company and return to Restaurant while Anne has breakfast at Restaurant, works at Company and has lunch at Restaurant. If we consider duration of staying on each location we can easily to differentiate their behaviors. In this paper, we propose a novel approach for discovering common behaviors by considering the duration of staying on each location of trajectories (DoSTra). Our approach can be used to detect the group that has similar lifestyle, habit or behavior patterns and predict the future locations of moving objects. We evaluate the experiment based on synthetic dataset, which demonstrates the high effectiveness and efficiency of the proposed method.