A construction for generalized hadamard matrices GH(4q, EA(q))

We give a construction for a generalized Hadamard matrix GH(4q, EA(q)) as a 4 × 4 matrix of q × q blocks, for q an odd prime power other than 3 or 5. Each block is a GH(q, EA(q)) and certain combinations of 4 blocks form GH(2q, EA(q)) matrices. Hence a GH(4q, EA(q)) matrix exists for every prime power q.     

Perceived barriers to walking in the neighborhood environment: a survey of middle-aged and older adults

The authors investigated whether low levels of walking among older adults in the UK were associated with demographic and health characteristics, as well as perceived environmental attributes. Survey data were obtained from self-administered standard questionnaires given to 680 people age 50+ (mean age 64.4 yr) attending nationally led walking schemes. Items concerned with demographic characteristics and perceived barriers to neighborhood walking were analyzed using multiple logistic regression. Citing more than 1 environmental barrier to walking, versus not, was associated with significantly reduced levels of (leisure) walking (MET/hr) in the preceding week (Z = -2.35, p = .019), but physical activity levels overall did not differ significantly (Z = -0.71, p = .48). Citing a health-related barrier to walking significantly adversely affected overall physical activity levels (Z = -2.72, p = .006). The authors concluded that, among older people who favor walking, health problems might more seriously affect overall physical activity levels than perceived environmental barriers.     

Getting into the ‘Giving Habit’: The Dynamics of Volunteering in the UK

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - Scholarship on volunteering has paid insufficient attention to how experiences of volunteering in the past affect current...     

Olympic news and attitudes towards the Olympics: a compositional time-series analysis of how sentiment is affected by events

Sentiment affects the evolving economic valuation of companies through the stock market. It is unclear how ‘news’ affects the sentiment towards major public investments like the Olympics. In this paper we consider, from the context of the pre-event stage of the 30th Olympiad, the relationship between attitudes towards the Olympics and Olympic-related news; specifically the bad news associated with an increase in the cost of provision, and the good news associated with Team Great Britain's medal success in 2008. Using a unique data set and an event-study approach that involves compositional time-series analysis, it is found that ‘good’ news affects sentiments much more than ‘bad’, but that the distribution of such sentiment varies widely. For example, a much more pronounced effect of good news is identified for females than males, but ‘bad’ news has less of an impact on the young and older age groups.     

Foreign aid and the rule of law: Institutional diffusion versus legal reach

This paper examines the role of bilateral foreign aid in supporting the diffusion and enactment of common models and institutions of the rule of law among aid-recipient low- and middle-income countries. We ask whether aid targeted at security-sector reform and the rule of law influences the adoption of constitutional and legal reforms over time (institutional diffusion), and whether aid also supports more effective implementation of the rule of law, writ large (legal reach). We use event history and fixed-effects panel regression models to examine a sample of 154 countries between 1995 and 2013 to answer these questions. Our findings suggest that aid does increase the likelihood of adopting several rule of law reforms, but its effect on increasing the depth or quality of rule of law over time within countries is much less substantial. These findings suggest that though aid may play a role in supporting the diffusion of models contributing to state isomorphism among countries, it is less effective at increasing the pervasiveness and quality of such model’s implementation. This discrepancy between the effectiveness of bilateral aid in promoting law on the books versus law in action in aid recipient countries calls into question the current approach to rule of law reforms.     

Predicting the Validity of Expert Judgments in Assessing the Impact of Risk Mitigation Through Failure Prevention and Correction

Operational risk management of autonomous vehicles in extreme environments is heavily dependent on expert judgments and, in particular, judgments of the likelihood that a failure mitigation action, via correction and prevention, will annul the consequences of a specific fault. However, extant research has not examined the reliability of experts in estimating the probability of failure mitigation. For systems operations in extreme environments, the probability of failure mitigation is taken as a proxy of the probability of a fault not reoccurring. Using a priori expert judgments for an autonomous underwater vehicle mission in the Arctic and a posteriori mission field data, we subsequently developed a generalized linear model that enabled us to investigate this relationship. We found that the probability of failure mitigation alone cannot be used as a proxy for the probability of fault not reoccurring. We conclude that it is also essential to include the effort to implement the failure mitigation when estimating the probability of fault not reoccurring. The effort is the time taken by a person (measured in person-months) to execute the task required to implement the fault correction action. We show that once a modicum of operational data is obtained, it is possible to define a generalized linear logistic model to estimate the probability a fault not reoccurring. We discuss how our findings are important to all autonomous vehicle operations and how similar operations can benefit from revising expert judgments of risk mitigation to take account of the effort required to reduce key risks.