A robust set-valued state estimation approach to the problem of vision based SLAM for mobile robots

The problem of visual simultaneous localization and mapping (SLAM) is examined in this paper using ideas and algorithms from robust control and estimation theory. Using a stereo-vision based sensor, a nonlinear measurement model is derived which leads to nonlinear measurements of the landmark coordinates along with optical flow based measurements of the relative robot-landmark velocity. Using a novel analytical measurement transformation, the nonlinear SLAM problem is converted into the linear filter is guaranteed stable and the ALAM state estimation error is bounded within an ellipsoidal set. No similar results are available for the commonly employed extended Kalman filter which is known to exhibit divergent and inconsistency characteristics in practice.

The impact of school tobacco policies on student smoking in Washington State, United States and Victoria, Australia

This paper measures tobacco polices in statewide representative samples of secondary and mixed schools in Victoria, Australia and Washington, US (N = 3,466 students from 285 schools) and tests their association with student smoking. Results from confounder-adjusted random effects (multi-level) regression models revealed that the odds of student perception of peer smoking on school grounds are decreased in schools that have strict enforcement of policy (odds ratio (OR) = 0.45; 95% CI: 0.25 to 0.82; p = 0.009). There was no clear evidence in this study that a comprehensive smoking ban, harsh penalties, remedial penalties, harm minimization policy or abstinence policy impact on any of the smoking outcomes.

Policing, rule of law, state capacity and sustainable peace in Timor-Leste

This paper sets out to demonstrate the link between development, state capacity and peace, employing Timor-Leste as the case study. It employs the association between state capacity and development to illustrate where if state capacity is lacking or functions improperly there is likely to be a low level of state legitimacy. This in turn manifests as lack of respect for or failure of rule of law, developing as generalised lawlessness and anti-state activity and eventually manifesting as intra-state or civil conflict. In particular, policing is seen as a critical component in state legitimacy, being the 'front line' of the judicial system from which legitimacy ultimately derives. This issue is particularly critical in states emerging from traditional legal and judicial structures, but which have not yet articulated into 'rational-legal' structures. Ipso facto, key state institutions, such as the judicial system and police are required to function well, while these are alone not enough to guarantee peace, they are significant contributors to and guarantors of peace.

Rural adolescent alcohol, tobacco, and illicit drug use: a comparison of students in Victoria, Australia, and Washington State, United States

Purpose: There are inconsistent research findings regarding the impact of rurality on adolescent alcohol, tobacco, and illicit substance use. Therefore, the current study reports on the effect of rurality on alcohol, tobacco, and illicit
drug use among adolescents in 2 state representative samples in 2 countries, Washington State (WA) in the United States and Victoria (VIC) in Australia.
Participants: The International Youth Development Study (IYDS) recruited representative samples of students from Grade 7 (aged 12 to 13 years) and Grade 9 (aged 14 to 15) in both states. A total of 3,729 students responded to questions about alcohol, tobacco, cannabis, and other illicit substance use (n_VIC = 1,852; n_WA = 1,877). In each state, males and females were equally represented and ages ranged from 12 to 15 years.
Methods: Data were analyzed to compare lifetime and current (past 30 days) substance use for students located in census areas classified as urban, large or small town, and rural. Findings were adjusted for school clustering and
weighted to compare prevalence at median age 14 years.
Findings: Rates of lifetime and current alcohol, tobacco, and cannabis use were significantly higher in rural compared to urban students in both states (odds ratio for current substance use = 1.31).
Conclusions: In both Washington State and Victoria, early adolescent rural students use substances more frequently than their urban counterparts. Future studies should examine factors that place rural adolescents at risk for alcohol, tobacco, and illicit drug use.

Hydrogen bonded block copolymer systems : from microphase separation in solid state to self-assembly in aqueous solutions

Block copolymer systems with hydrogen bonding interactions have received relatively little attention. Recently, we have investigated the self-assembly and phase separation in such block copolymer systems with an attempt to elucidate the role of hydrogen bonding interactions both theoretically and experimentally [1-4]. In A-b-B/C diblock copolymer/homopolymer systems, the phase behavior was theoretically analyzed according to the random phase approximation and correlated with hydrogen bonding interactions in terms of the difference in inter-association constants (K). To examine how the hydrogen bonding determines the self-assembly and morphological transitions in these systems, we have introduced the K values as a new variable into the phase diagram which we established for the first time (Fig. 1). Multiple vesicular morphologies were formed in aqueous solution of A-b-B/A-b-C diblock copolymer complexes of PS-b-PAA and PS-b-PEO. Interconnected compound vesicles (ICCVs) were observed for the first time as a new morphology (Fig. 2), along with other aggregated nanostructures including vesicles, multilamellar vesicles, thick-walled vesicles and irregular aggregates. Complexation of two amphiphilic diblock copolymers provides a viable approach to vesicles in aqueous media.

Predictors and responses to the growth in physical violence during adolescence : a comparison of students in Washington State and Victoria, Australia

This study investigates patterns in violence over 3 time points in early to midadolescence in 2 statewide representative samples of youth, one in Washington State, USA, and the other in Victoria, Australia. Comparable data collection methods in both states were used to cross-nationally compare patterns of violence, risk factors, and responses to violence (school suspensions and arrests) in 2 policy contexts. Risk factors include early use of alcohol, binge drinking, involvement with antisocial peers, family conflict, poor family management, sensation seeking, and bully victimization. These are modeled as correlates of initial violence and predictors of change in violence over a 3-year period, from ages 12–15, for participating youth. Results suggest that patterns and predictors of violence are mostly similar in the 2 states. Initial levels of violence (age 13) and change over time in violence were associated in both states with more youth school suspensions and more police arrests in Grade 9. Some cross-national differences were also shown. For example, correlations of violence with gender and violence with binge drinking were stronger in Victoria, whereas correlations of violence with early use of alcohol and with antisocial peer involvement were stronger in Washington State. Antisocial peer involvement and family conflict were significant predictors of a gradual increase in violence from Grades 7–9 for youth in Victoria only. Implications are discussed with attention to prevention and intervention efforts.

Hierarchical hidden Markov models with general state hierarchy

The hierarchical hidden Markov model (HHMM) is an extension of the hidden Markov model to include a hierarchy of the hidden states. This form of hierarchical modeling has been found useful in applications such as handwritten character recognition, behavior recognition, video indexing, and text retrieval. Nevertheless, the state hierarchy in the original HHMM is restricted to a tree structure. This prohibits two different states from having the same child, and thus does not allow for sharing of common substructures in the model. In this paper, we present a general HHMM in which the state hierarchy can be a lattice allowing arbitrary sharing of substructures. Furthermore, we provide a method for numerical scaling to avoid underflow, an important issue in dealing with long observation sequences. We demonstrate the working of our method in a simulated environment where a hierarchical behavioral model is automatically learned and later used for recognition.

Pathways from school suspension to adolescent nonviolent antisocial behavior in students in Victoria, Australia and Washington State, United States

School suspension is associated with school dropout, crime, delinquency, and alcohol and other drug use for the suspended student. Important research questions are how academic and related factors are relevant to the school suspension process and the generality of the process in different sites. State-representative samples of Grade 7 students (N = 1,945) in Washington State, United States and Victoria, Australia were followed from 2002 to 2004. In both states, Grade 7 school suspension was associated with higher rates of nonviolent antisocial behavior and suspension 24 months later, before Grade 8 factors were entered into the model. Relevant factors were Grade 8 low school grades and association with antisocial peers, as well as Grade 8 antisocial behavior in Washington State only. The implications of these findings for the ways in which suspension is used in schools are outlined.

State-of-the-art review and critical success factors for mobile business intelligence

Due to ubiquitous information requirements, market interest in mobile business intelligence (BI) has grown markedly. However, mobile BI market is a relatively new area that has been driven primarily by the IT industry. Yet, there is a lack of systematic study on the critical success factors for mobile BI. This research reviews the state-of-the-art of mobile BI, and explores the critical success factors based on a rigorous examination of the academic and practitioner literature. The study reveals that critical success factors of mobile BI generally fall into four key dimensions, namely security, mobile technology, system content and quality, and organisational support perspectives. The various research findings will be useful to organisations which are considering or undertaking mobile business intelligence initiatives.

Does the burden of the experience sampling method undermine data quality in state based body image research?

Despite growing popularity of experience sampling methodology (ESM) for evaluations of state-based components of body image, there have been concerns that the frequent repeated measurement might encourage problematic responding resulting in low data quantity and/or quality. Using a sample of 105 women (mean age = 24.84), this study used multilevel modelling to investigate whether (a) there were changes in compliance or response variability across a 7-day period, and (b) whether such changes are explained by participant characteristics. Present findings suggest that demands of ESM protocol undermine quantity more so than quality of obtained data. Decline in procedural compliance across the testing period correlated with BMI and body shame, whereas reduced variability in state-based assessments did not adversely impact the strength of association between state body satisfaction ratings and other variables in the dataset. The authors make several recommendations for ensuring the quality of ESM-based data in future studies.

Does school suspension affect subsequent youth non-violent antisocial behaviour? A longitudinal study of studnets in Victoria, Australia and Washington State, United States

School suspension has been not only associated with negative behaviours but also is predictive of future poor outcomes. The current study investigates (1) whether school suspension is a unique predictor of youth non-violent antisocial behaviour (NVAB) relative to other established predictors, and (2) whether the predictors of NVAB are similar in Australia and the United States (USA). The data analysed here draw on two statewide representative samples of Grade 7 and 9 students in Victoria, Australia and Washington State, USA, resurveyed at 12-month follow-up (N = 3,677, 99% retention). School suspension did not uniquely predict NVAB in the final model. The predictors of NVAB, similar across states, included previous student NVAB, current alcohol and tobacco use, poor family management, association with antisocial friends, and low commitment to school. An implication of the findings is that US evidence-based prevention programmes targeting the influences investigated here could be trialled in Australia.

State body dissatisfaction and social interactions : an experience sampling study

To date, there has been limited empirical scrutiny of the correlates and consequences of day-to-day state body dissatisfaction fluctuations within naturalistic contexts. We used ecological momentary assessment (a form of naturalistic observation) to evaluate whether state body dissatisfaction was concurrently and/or prospectively associated with occurrence and quality of social interactions. Women (N = 121), aged 18 to 40, completed a brief trait-based survey and then nominated a 7-day period within which to receive seven text messages daily, at random intervals, prompting them to complete measures of body dissatisfaction at that moment. If they were currently or had recently engaged in social interactions, they were also asked to fill out questions rating the quality of these interactions (operationalized in terms of enjoyment of, and control in, the interaction). Findings suggest that the relationship between state body dissatisfaction and aspects of social interactions is complex and may vary over time. Cross-sectionally, state body dissatisfaction and social interaction quality were negatively associated. Prospectively, however, body dissatisfaction predicted subsequent avoidance of social interactions. Interestingly, when women chose to avoid social interactions, their body dissatisfaction worsened, yet when they did engage in social interactions, they reported improved body satisfaction. Importantly, the links between state body dissatisfaction and social interactions may be moderated by body mass index and trait body satisfaction levels. Potential mechanisms underlying the association between state body dissatisfaction and quality and quantity of social interactions are discussed, and future research avenues are proposed to further understand their inter-relation.