Asymptotics for incidence matrix classes

We define {\em incidence matrices} to be zero-one matrices with no zero rows or columns. A classification of incidence matrices is considered for which conditions of symmetry by transposition, having no repeated rows/columns, or identification by permutation of rows/columns are imposed. We find asymptotics and relationships for the number of matrices with $n$ ones in these classes as $n\to\infty$.Comment: updated and slightly expanded versio

Asymptotic enumeration of 2-covers and line graphs

In this paper we find asymptotic enumerations for the number of line graphs on $n$-labelled vertices and for different types of related combinatorial objects called 2-covers. We find that the number of 2-covers, $s_n$, and proper 2-covers, $t_n$, on $[n]$ both have asymptotic growth $$s_n\sim t_n\sim B_{2n}2^{-n}\exp(-\frac12\log(2n/\log n))= B_{2n}2^{-n}\sqrt{\frac{\log n}{2n}},$$ where $B_{2n}$ is the $2n$th Bell number, while the number of restricted 2-covers, $u_n$, restricted, proper 2-covers on $[n]$, $v_n$, and line graphs $l_n$, all have growth $$u_n\sim v_n\sim l_n\sim B_{2n}2^{-n}n^{-1/2}\exp(-[\frac12\log(2n/\log n)]^2).$$ In our proofs we use probabilistic arguments for the unrestricted types of 2-covers and and generating function methods for the restricted types of 2-covers and line graphs

Asymptotic enumeration of incidence matrices

We discuss the problem of counting {\em incidence matrices}, i.e. zero-one matrices with no zero rows or columns. Using different approaches we give three different proofs for the leading asymptotics for the number of matrices with $n$ ones as $n\to\infty$. We also give refined results for the asymptotic number of $i\times j$ incidence matrices with $n$ ones.Comment: jpconf style files. Presented at the conference "Counting Complexity: An international workshop on statistical mechanics and combinatorics." In celebration of Prof. Tony Guttmann's 60th birthda

Community hospitals – the place of local service provision in a modernising NHS: an integrative thematic literature review

Background: Recent developments within the United Kingdom's (UK) health care system have reawakened interest in community hospitals (CHs) and their role in the provision of health care. This integrative literature review sought to identify and assess the current evidence base for CHs. Methods: A range of electronic reference databases were searched from January 1984 to either December 2004 or February 2005: Medline, Embase, Web of Knowledge, BNI, CINAHL, HMIC, ASSIA, PsychInfo, SIGLE, Dissertation Abstracts, Cochrane Library, Kings Fund website, using both keywords and text words. Thematic analysis identified recurrent themes across the literature; narrative analyses were written for each theme, identifying unifying concepts and discrepant issues. Results: The search strategy identified over 16,000 international references. We included papers of any study design focussing on hospitals in which care was led principally by general practitioners or nurses. Papers from developing countries were excluded. A review of titles revealed 641 potentially relevant references; abstract appraisal identified 161 references for review. During data extraction, a further 48 papers were excluded, leaving 113 papers in the final review. The most common methodological approaches were cross-sectional/descriptive studies, commentaries and expert opinion. There were few experimental studies, systematic reviews, economic studies or studies that reported on longer-term outcomes. The key themes identified were origin and location of CHs; their place in the continuum of care; services provided; effectiveness, efficiency and equity of CHs; and views of patients and staff. In general, there was a lack of robust evidence for the role of CHs, which is partly due to the ad hoc nature of their development and lack of clear strategic vision for their future. Evidence for the effectiveness and efficiency of the services provided was limited. Most people admitted to CHs appeared to be older, suggesting that admittance to CHs was age-related rather than condition-related. Conclusion: Overall the literature surveyed was long on opinion and short of robust studies on CHs. While lack of evidence on CHs does not imply lack of effect, there is an urgent need to develop a research agenda that addresses the key issues of health care delivery in the CH setting

A conceptual model of suicide in rural areas

Context: Suicide is an important public health issue among rural communities although there is no single pattern of suicide in rural areas. Despite this, there are common themes in much of the research evidence on suicide in rural areas. From the published research in the area, a conceptual model of rural suicide has been developed which can be used by clinical and public health services when considering possible routes of intervention.Issue: A conceptual model can be defined as 'a type of diagram which shows a set of relationships between factors that are believed to impact or lead to a target condition'. The model presented here uses the 'Cry of pain/ Entrapment' model of suicide risk to build a framework of factors which are associated with suicide in rural areas. Cross-setting factors associated with suicide rates include gender, poverty, mental illness, substance use, biological factors including apparent genetic risk, coping skills and media coverage of suicide. There are, however, other factors that appear to have particular importance in rural areas. These include rural stressors, such as isolation and political and social exclusion; factors affecting support, including social support, cultural norms on help-seeking, stigma associated with mental illness service availability; factors affecting the decision to self-harm, including modelling and cultural views on self-harm, and issues affecting the likelihood of self-harm resulting in death, including method availability, norms on methods of self-harm and treatment availability after harm occurs. Identifying which of these areas are the greatest local priorities helps to target activity.Lessons learned: This model provides a way of considering suicide in rural areas. Local staff can use it to consider which issues are most relevant to their area. It allows classification of existing interventions, and deciding which other areas of work might be of local value. For researchers and service planners, it provides a way of classifying interventions and describing projects

Evaluation of career readiness at an industrial technology program using a fuzzy approach

In this research, a quantitative model to measure the “career readiness” performance level of the current curriculum of the Industrial Technology and Packaging program at California Polytechnic State University is proposed. Career readiness is first defined through performance attributes and these attributes are further classified into specific categories and metrics. Using a fuzzy logic computational approach, “career readiness” measures are developed and a “career readiness” score referred to as (CRS) is calculated. The model is designed to be flexible, dynamic and easy to use. It should enable a systematic measurement of career readiness by producing a final integrated unit-less score. Results from the data collected for the Industrial Technology program’s main employers and graduates provided various insights about the level of career readiness the program currently provides in terms of strengths and weaknesses. In addition, these results, and the developed CRS approach, may serve as a practical tool for decision-making and improvement to various educational components to increase readiness level. Finally, the overall CRS, as well as its constituting scores, can be used to monitor progress along such improvements programs

A theoretical analysis of the impact of atmospheric parameters on the spectral, electrical and thermal performance of a concentrating III–V triple-junction solar cell

The spectral sensitivity of a concentrating triple junction (3J) solar cell has been investigated. The atmospheric parameters such as the air mass (AM), aerosol optical depth (AOD) and precipitable water (PW) change the distribution of the solar spectrum in a way that the spectral, electrical and thermal performance of a 3J solar cell is affected. In this paper, the influence of the spectral changes on the performance of each subcell and whole cell has been analysed. It has been shown that increasing the AM and AOD have a negative impact on the spectral and electrical performance of 3J solar cells while increasing the PW has a positive effect, although, to a lesser degree. A three-dimensional finite element analysis model is used to quantify the effect of each atmospheric parameter on the thermal performance for a range of heat transfer coefficients from the back-plate to the ambient air and also ambient temperature. It is shown that a heat transfer coefficient greater than 1300 W/(m(2) K) is required to keep the solar cell under 100 degrees C at all times. In order to get a more realistic assessment and also to investigate the effect of heat transfer coefficient on the annual energy yield, the methodology is applied for four US locations using data from a typical meteorological year (TMY3)

Down syndrome and Alzheimer\u27s disease: A scoping review of functional performance and fall risk

INTRODUCTION: Alzheimer\u27s disease (AD) occurs in aging adults with Down syndrome (DS) at a higher prevalence and an earlier age than in typical aging adults. As with the general aging adult population, there is an urgent need to understand the preclinical and early phases of AD progression in the adult population with DS. The aim of this scoping review was to synthesize the current state of the evidence and identify gaps in the literature regarding functional activity performance and falls and their significance to disease staging (i.e., mild, moderate, and severe defined staging criteria) in relation to Alzheimer\u27s disease and related dementias (ADRD) in adults with DS. METHODS: This scoping review included six electronic databases (e.g., PsycInfo, Academic Search Complete, CINAHL, COCHRANE Library, MEDLINE, and PubMed). Eligible studies included participants with DS ≥25 years of age, studies with functional measures and/or outcomes (e.g., activities of daily living, balance, gait, motor control, speech, behavior, and cognition; falls; and fall risks), and studies that investigated AD pathology and implications. RESULTS: Fourteen eligible studies were included and categorized through a thematic analysis into the following themes: (1) physical activity and motor coordination (PAMC), (2) cognition, (3) behavior, and (4) sleep. The studies indicated how functional activity performance and engagement may contribute to early identification of those at risk of cognitive decline and AD development and/or progression. DISCUSSION: There is a need to expand the research regarding ADRD pathology relative to functional outcomes in adults with DS. Functional measures related to disease staging and cognitive impairment are essential to understanding how AD progression is characterized within real-world settings. This scoping review identified the need for additional mixed-methods research to examine the use of assessment and intervention related to function and its detection of cognitive decline and AD progression

A structural decomposition-based diagnosis method for dynamic process systems using HAZID information

A novel diagnosis method is proposed in this paper that uses the results of the blended HAZID analysis extended to the dynamic case of process systems controlled by operational procedures. The algorithm is capable of finding fault root causes in process systems using nominal and observed possible faulty operational procedure execution traces. The algorithm uses the structural decomposition of the process system and its component-level dynamic HAZID (P-HAZID) tables and executes the diagnosis component-wise by first decomposing the observed execution traces, and then assembling the diagnosis results. The exact structure of the algorithm is also discussed, followed by two case studies on which its operation is demonstrated. © 2014 Elsevier Ltd