Gaussian proposal density using moment matching in SMC methods

In this article we introduce a new Gaussian proposal distribution to be used in conjunction with the sequential Monte Carlo (SMC) method for solving non-linear filtering problems. The proposal, in line with the recent trend, incorporates the current observation. The introduced proposal is characterized by the exact moments obtained from the dynamical system. This is in contrast with recent works where the moments are approximated either numerically or by linearizing the observation model. We show further that the newly introduced proposal performs better than other similar proposal functions which also incorporate both state and observations. This work was supported by a research grant from THALES Nederland BV.     

Urban bird conservation: presenting stakeholder-specific arguments for the development of bird-friendly cities

Following the call from the United Nations Convention on Biological Diversity “Cities & Biodiversity Outlook” project to better preserve urban biodiversity, this paper presents stakeholder-specific statements for bird conservation in city environments. Based upon the current urban bird literature we focus upon habitat fragmentation, limited habitat availability, lack of the native vegetation and vegetation structure as the most important challenges facing bird conservation in cities. We follow with an overview of the stakeholders in cities, and identify six main groups having the greatest potential to improve bird survival in cities: i) urban planners, urban designers and (landscape) architects, ii) urban developers and engineers, iii) homeowners and tenants, iv) companies and industries, v) landscaping and gardening firms, vi) education professionals. Given that motivation to act positively for urban birds is linked to stakeholder-specific advice, we present ten statements for bird-friendly cities that are guided by an action perspective and argument for each stakeholder group. We conclude with a discussion on how the use of stakeholder-specific arguments can enhance and rapidly advance urban bird conservation action.     

Infant death clustering in families: magnitude, causes, and the influence of better health services, Bangladesh 1982-2005

This analysis of infant mortality in Bangladesh focuses on explaining death clustering within families, using prospective data from a rural region in Bangladesh, split into areas with and without extensive health services (the area covered by the International Centre for Diarrhoeal Disease Research and the comparison area, respectively). The modelling framework distinguishes between two explanations of death clustering: (observed and unobserved) heterogeneity across families and a causal 'scarring' effect of the death of one infant on the survival chances of the next to be born. Keeping observed and unobserved characteristics constant, we find scarring in the comparison area only. There the likelihood of infant death is about 29 per cent greater if the previous sibling died in infancy than otherwise. This effect mainly works through birth intervals: infant deaths are followed by shorter birth intervals, which increases the risk of infant death for the next child.     

A GENERALIZED TWO-STAGE RANDOMIZED RESPONSE PROCEDURE IN COMPLEX SAMPLE SURVEYS

The randomized response (RR) technique pioneered by Warner, S.L. (1965) [Randomised response: a survey technique for eliminating evasive answer bias. J. Amer. Statist. Assoc. 60 , 63–69] is a useful tool in estimating the proportion of persons in a community bearing sensitive or socially disapproved characteristics. Mangat, N.S. & Singh, R. (1990) [An alternative rendomized response procedure. Biometrika 77 , 439–442] proposed a modification of Warner's procedure by using two RR techniques. Presented here is a generalized two‐stage RR procedure and derivation of the condition under which the proposed procedure produces a more precise estimator of the population parameter. A comparative study on the performance of this two‐stage procedure and conventional RR techniques, assuming that the respondents' jeopardy level in this proposed method remains the same as that offered by the traditional RR procedures, is also reported. In addition, a numerical example compares the efficiency of the proposed method with the traditional RR procedures.     

Social Coping and Life Satisfaction in Adolescents

This study examined the relationships among early adolescent social coping behavior and measures of subjective well-being, specifically global life satisfaction and friend satisfaction. A total of 1,011 students in grades 7–8 at a southeastern US middle school completed measures of global life satisfaction, friend satisfaction and coping, on two occasions, 5 months apart. Social support seeking coping behavior at Time 1, but not problem-solving, distancing, internalizing or externalizing coping behaviors at Time 1, uniquely predicted global life satisfaction and friend satisfaction at Time 2. Implications for research and promoting adolescent well-being are discussed.     

Representing employee requirements in labour tour scheduling

In this paper, we use the methodology of simulation to evaluate six approaches for handling employee requirements in an LP-based labour tour scheduling heuristic. We model employee requirements both as minimum acceptable staffing levels—where understaffing is unacceptable—and as target staffing levels—where both under- and overstaffing are acceptable. For each representation of employee requirements, we evaluate forms of the heuristic that use problem-specific and problem-independent information on the costs of employee surpluses and, if appropriate, employee shortages. Over an extensive test data set, the target-staffing approach using problem-specific cost information outperformed all other procedures. Specifically, it generated schedules costing less than 87% of those developed using the approach most commonly found in the literature. Its schedules were also almost 5% cheaper than those of its closest competitor. We discuss the managerial and research implications of the findings and provide suggestions for future research.     

Optimal weighing designs with a string property

We consider the usual (spring balance) weighing design set-up with the design matrix having a string property meaning thereby that in every row of it, there is exactly one run of 1's (the rest of the elements being 0's). We have investigated some interesting features of such matrices and used them in deriving various optimality results.     

“I Amn Not a Utistivc on Thje Typ” (“I'm Not Autistic on the Typewriter”)

Facilitated communication involves hand-over-hand or hand-on-forearm support of students as they communicate through pointing at pictures, letters or other objects. Over time, it is expected that the hand and arm support can be faded back. This observational study describes an effort to introduce facilitated communication to 22 students, ranging in age from 3 years 10 months to 21 years, in several US public schools. The students are all labeled autistic and do not speak or speak only with echolalic phrases. The findings include observations of the students communicating with facilitation, language samples, and conversations by the students. The students reveal unexpected literacy and numeracy skills. The appearance of these abilities raises a number of questions concerning prior assumptions about autism, communication, independence and interdependence, and the education of students with and without disabilities.