Expert elicitation into Bayesian networks, Part 1 of 4 : understanding probability

An introduction to elicitation of experts' probabilities, which illustrates common problems with reasoning and how to circumvent them during elicitation.

Identifying parent perspectives to guide active travel intervention with small populations : case study in Denver, Colorado

This paper investigates a strategy for guiding school-based active travel intervention. School-based active travel programs address the travel behaviors and perceptions of small target populations (i.e., at individual schools) so they can encourage people to walk or bike. Thus, planners need to know as much as possible about the behaviors and perceptions of their target populations. However, existing strategies for modeling travel behavior and segmenting audiences typically work with larger populations and may not capture the attitudinal diversity of smaller groups. This case study used Q technique to identify salient travel-related attitude types among parents at an elementary school in Denver, Colorado; 161 parents presented their perspectives about school travel by rank-ordering 36 statements from strongly disagree to strongly agree in a normalized distribution, single centered around no opinion. Thirty-nine respondents' cases were selected for case-wise cluster analysis in SPSS according to criteria that made them most likely to walk: proximity to school, grade, and bus service. Analysis revealed five core perspectives that were then correlated with the larger respondent pool: optimistic walkers, fair-weather walkers, drivers of necessity, determined drivers, and fence sitters. Core perspectives are presented—characterized by parents' opinions, personal characteristics, and reported travel behaviors—and recommendations are made for possible intervention approaches. The study concludes that Q technique provides a fine-grained assessment of travel behavior for small populations, which would benefit small-scale behavioral interventions

Body composition and its relationship to metabolic risk factors in Asian children

Obesity is a major public health problem in both developed and developing countries. The body mass index (BMI) is the most common index used to define obesity. The universal application of the same BMI classification across different ethnic groups is being challenged due to the inability of the index to differentiate fat mass (FM) and fat�]free mass (FFM) and the recognized ethnic differences in body composition. A better understanding of the body composition of Asian children from different backgrounds would help to better understand the obesity�]related health risks of people in this region. Moreover, the limitations of the BMI underscore the necessity to use where possible, more accurate measures of body fat assessment in research and clinical settings in addition to BMI, particularly in relation to the monitoring of prevention and treatment efforts. The aim of the first study was to determine the ethnic difference in the relationship between BMI and percent body fat (%BF) in pre�]pubertal Asian children from China, Lebanon, Malaysia, the Philippines, and Thailand. A total of 1039 children aged 8�]10 y were recruited using a non�]random purposive sampling approach aiming to encompass a wide BMI range from the five countries. Percent body fat (%BF) was determined using the deuterium dilution technique to quantify total body water (TBW) and subsequently derive proportions of FM and FFM. The study highlighted the sex and ethnic differences between BMI and %BF in Asian children from different countries. Girls had approximately 4.0% higher %BF compared with boys at a given BMI. Filipino boys tended to have a lower %BF than their Chinese, Lebanese, Malay and Thai counterparts at the same age and BMI level (corrected mean %BF was 25.7�}0.8%, 27.4�}0.4%, 27.1�}0.6%, 27.7�}0.5%, 28.1�}0.5% for Filipino, Chinese, Lebanese, Malay and Thai boys, respectively), although they differed significantly from Thai and Malay boys. Thai girls had approximately 2.0% higher %BF values than Chinese, Lebanese, Filipino and Malay counterparts (however no significant difference was seen among the four ethnic groups) at a given BMI (corrected mean %BF was 31.1�}0.5%, 28.6�}0.4%, 29.2�}0.6%, 29.5�}0.6%, 29.5�}0.5% for Thai, Chinese, Lebanese, Malay and Filipino girls, respectively). However, the ethnic difference in BMI�]%BF relationship varied by BMI. Compared with Caucasians, Asian children had a BMI 3�]6 units lower for a given %BF. More than one third of obese Asian children in the study were not identified using the WHO classification and more than half were not identified using the International Obesity Task Force (IOTF) classification. However, use of the Chinese classification increased the sensitivity by 19.7%, 18.1%, 2.3%, 2.3%, and 11.3% for Chinese, Lebanese, Malay, Filipino and Thai girls, respectively. A further aim of the first study was to determine the ethnic difference in body fat distribution in pre�]pubertal Asian children from China, Lebanon, Malaysia, and Thailand. The skin fold thicknesses, height, weight, waist circumference (WC) and total adiposity (as determined by deuterium dilution technique) of 922 children from the four countries was assessed. Chinese boys and girls had a similar trunk�]to�]extremity skin fold thickness ratio to Thai counterparts and both groups had higher ratios than the Malays and Lebanese at a given total FM. At a given BMI, both Chinese and Thai boys and girls had a higher WC than Malays and Lebanese (corrected mean WC was 68.1�}0.2 cm, 67.8�}0.3 cm, 65.8�}0.4 cm, 64.1�}0.3 cm for Chinese, Thai, Lebanese and Malay boys, respectively; 64.2�}0.2 cm, 65.0�}0.3 cm, 62.9�}0.4 cm, 60.6�}0.3 cm for Chinese, Thai, Lebanese and Malay girls, respectively). Chinese boys and girls had lower trunk fat adjusted subscapular/suprailiac skinfold ratio compared with Lebanese and Malay counterparts. The second study aimed to develop and cross�]validate bioelectrical impedance analysis (BIA) prediction equations of TBW and FFM for Asian pre�]pubertal children from China, Lebanon, Malaysia, the Philippines, and Thailand. Data on height, weight, age, gender, resistance and reactance measured by BIA were collected from 948 Asian children (492 boys and 456 girls) aged 8�]10 y from the five countries. The deuterium dilution technique was used as the criterion method for the estimation of TBW and FFM. The BIA equations were developed from the validation group (630 children randomly selected from the total sample) using stepwise multiple regression analysis and cross�]validated in a separate group (318 children) using the Bland�]Altman approach. Age, gender and ethnicity influenced the relationship between the resistance index (RI = height2/resistance), TBW and FFM. The BIA prediction equation for the estimation of TBW was: TBW (kg) = 0.231�~Height2 (cm)/resistance (ƒ¶) + 0.066�~Height (cm) + 0.188�~Weight (kg) + 0.128�~Age (yr) + 0.500�~Sex (male=1, female=0) . 0.316�~Ethnicity (Thai ethnicity=1, others=0) �] 4.574, and for the estimation of FFM: FFM (kg) = 0.299�~Height2 (cm)/resistance (ƒ¶) + 0.086�~Height (cm) + 0.245�~Weight (kg) + 0.260�~Age (yr) + 0.901�~Sex (male=1, female=0) �] 0.415�~Ethnicity (Thai ethnicity=1, others=0) �] 6.952. The R2 was 88.0% (root mean square error, RSME = 1.3 kg), 88.3% (RSME = 1.7 kg) for TBW and FFM equation, respectively. No significant difference between measured and predicted TBW and between measured and predicted FFM for the whole cross�]validation sample was found (bias = �]0.1�}1.4 kg, pure error = 1.4�}2.0 kg for TBW and bias = �]0.2�}1.9 kg, pure error = 1.8�}2.6 kg for FFM). However, the prediction equation for estimation of TBW/FFM tended to overestimate TBW/FFM at lower levels while underestimate at higher levels of TBW/FFM. Accuracy of the general equation for TBW and FFM compared favorably with both BMI�]specific and ethnic�]specific equations. There were significant differences between predicted TBW and FFM from external BIA equations derived from Caucasian populations and measured values in Asian children. There were three specific aims of the third study. The first was to explore the relationship between obesity and metabolic syndrome and abnormalities in Chinese children. A total of 608 boys and 800 girls aged 6�]12 y were recruited from four cities in China. Three definitions of pediatric metabolic syndrome and abnormalities were used, including the International Diabetes Federation (IDF) and National Cholesterol Education Program (NCEP) definition for adults modified by Cook et al. and de Ferranti et al. The prevalence of metabolic syndrome varied with different definitions, was highest using the de Ferranti definition (5.4%, 24.6% and 42.0%, respectively for normal�]weight, overweight and obese children), followed by the Cook definition (1.5%, 8.1%, and 25.1%, respectively), and the IDF definition (0.5%, 1.8% and 8.3%, respectively). Overweight and obese children had a higher risk of developing the metabolic syndrome compared to normal�]weight children (odds ratio varied with different definitions from 3.958 to 6.866 for overweight children, and 12.640�]26.007 for obese children). Overweight and obesity also increased the risk of developing metabolic abnormalities. Central obesity and high triglycerides (TG) were the most common while hyperglycemia was the least frequent in Chinese children regardless of different definitions. The second purpose was to determine the best obesity index for the prediction of cardiovascular (CV) risk factor clustering across a 2�]y follow�]up among BMI, %BF, WC and waist�]to�]height ratio (WHtR) in Chinese children. Height, weight, WC, %BF as determined by BIA, blood pressure, TG, high�]density lipoprotein cholesterol (HDL�]C), and fasting glucose were collected at baseline and 2 years later in 292 boys and 277 girls aged 8�]10 y. The results showed the percentage of children who remained overweight/obese defined on the basis of BMI, WC, WHtR and %BF was 89.7%, 93.5%, 84.5%, and 80.4%, respectively after 2 years. Obesity indices at baseline significantly correlated with TG, HDL�]C, and blood pressure at both baseline and 2 years later with a similar strength of correlations. BMI at baseline explained the greatest variance of later blood pressure. WC at baseline explained the greatest variance of later HDL�]C and glucose, while WHtR at baseline was the main predictor of later TG. Receiver�]operating characteristic (ROC) analysis explored the ability of the four indices to identify the later presence of CV risk. The overweight/obese children defined on the basis of BMI, WC, WHtR or %BF were more likely to develop CV risk 2 years later with relative risk (RR) scores of 3.670, 3.762, 2.767, and 2.804, respectively. The final purpose of the third study was to develop age�] and gender�]specific percentiles of WC and WHtR and cut�]off points of WC and WHtR for the prediction of CV risk in Chinese children. Smoothed percentile curves of WC and WHtR were produced in 2830 boys and 2699 girls aged 6�]12 y randomly selected from southern and northern China using the LMS method. The optimal age�] and gender�]specific thresholds of WC and WHtR for the prediction of cardiovascular risk factors clustering were derived in a sub�]sample (n=1845) by ROC analysis. Age�] and gender�]specific WC and WHtR percentiles were constructed. The WC thresholds were at the 90th and 84th percentiles for Chinese boys and girls, respectively, with sensitivity and specificity ranging from 67.2% to 83.3%. The WHtR thresholds were at the 91st and 94th percentiles for Chinese boys and girls, respectively, with sensitivity and specificity ranging from 78.6% to 88.9%. The cut�]offs of both WC and WHtR were age�] and gender�]dependent. In conclusion, the current thesis quantifies the ethnic differences in the BMI�]%BF relationship and body fat distribution between Asian children from different origins and confirms the necessity to consider ethnic differences in body composition when developing BMI and other obesity index criteria for obesity in Asian children. Moreover, ethnicity is also important in BIA prediction equations. In addition, WC and WHtR percentiles and thresholds for the prediction of CV risk in Chinese children differ from other populations. Although there was no advantage of WC or WHtR over BMI or %BF in the prediction of CV risk, obese children had a higher risk of developing the metabolic syndrome and abnormalities than normal�]weight children regardless of the obesity index used.

ThinkLifecycle

Exhibited at The Fashioning the Future Awards Showcase exhibition Fashioning the Future Awards is the leading international cross-disciplinary platform for celebrating innovative initiatives towards fashion design for sustainability, its development and communication. The 2011 awards are a showcase for exceptional work that celebrates ‘Unique’ ways to create our futures. Fashioning the Future is designed and coordinated by the Centre for Sustainable Fashion at London College of Fashion. Unique Enterprise Award The Unique Enterprise Award was offered for the consideration of the opportunities that arise from the necessity to solve the issues around water, waste, wellbeing, energy, equality and biodiversity. Winner Alice Payne According to Alice Payne there is no one-size-fits-all approach to creating a sustainable fashion system. Existing companies will need to evolve, change the way they design and produce garments, offer services rather than products, and engage with the end user to consider the end of life and future lives of their garments. The ThinkLifecycle content management system (CMS) acts as a bridge between existing industry practices and new, redirected practice in which sustainability is at the forefront of commercial thinking. Its chief aim is to embed lifecycle thinking within a company at a daily, operational level.

Position paper : redefining knowledge-based urban development

The concept of knowledge-based urban development has first come to the urban planning and development agenda during the very last years of the 20th century as a promising paradigm to support the transformation process of cities into knowledge cities and their societies into knowledge societies. However, soon after the exponentially rapid advancements experienced, during the first decade of the 21st century, particularly, in the domains of economy, society, management and technology along with the severe impacts of climate change, have made the redefinition of the term a necessity. This paper, first, reports the findings of the review of the relatively short but dynamic history of urbanisation experiences of our cities around the globe. The paper, then, focuses on the 21st century urbanisation context and discusses the conceptual base of the knowledge-based development of cities and how this concept found application ground in many parts of the world. Following this, the paper speculates development of future cities by particularly highlighting potential challenges and opportunities that previously have not been fully considered. This paper, lastly, introduces and elaborates how relevant theories support the better conceptualisation of this relatively new, but rapidly emerging paradigm, and redefines it accordingly.

Different kinds of openings of Luhmann's systems theory: A reply to la Cour et al

Various researchers have called for an 'opening up' of Luhmann's systems theory. We take this short paper as an occasion for a critical reflection on the necessity, existence and possibilities of such an opening. We start by pointing out the inherent openness of Luhmann's theory, and, based on this, discuss three kinds of openings: the international opening, the theoretical opening and the empirical opening. With regard to the latter, we distinguish three general options of using Luhmann's theory for empirical research. Copyright © 2007 SAGE.

Creative suburbia : rethinking urban cultural policy – the Australian case

This article considers the question of whether creative workers demonstrate a preference for inner cities or suburbs, drawing upon research findings from the ‘Creative Suburbia’ project undertaken by a team of Australian researchers over 2008–2010 in selected suburban areas of Brisbane and Melbourne. Locating this question in wider debates about the relationship of the suburbs to the city, as well as the development of new suburban forms such as master-planned communities, the article finds that the number of creative industries workers located in the suburbs is significant, and those creative workforce members living and working in suburban areas are generally happy with this experience, locating in the suburbs out of personal choice rather than economic necessity. This runs counter to the received wisdom on creative cities, which emphasize cultural amenity in inner city areas as a primary driver of location decisions for the ‘creative class’. The article draws out some implications of the findings for urban cultural policy, arguing that the focus on developing inner urban cultural amenity has been overplayed, and that more attention should be given to how to better enable distributed knowledge systems through high-speed broadband infrastructure.

Transferring knowledge through peer-reviewed assessment : the creation of a community of practice and the threats to its survival

While it is generally accepted in the learning and teaching literature that assessment is the single biggest influence on how students approach their learning, assessment methods within higher education are generally conservative and inflexible. Constrained by policy and accreditation requirements and the need for the explicit articulation of assessment standards for public accountability purposes, assessment tasks can fail to engage students or reflect the tasks students will face in the world of practice. Innovative assessment design can simultaneously deliver program objectives and active learning through a knowledge transfer process which increases student participation. This social constructivist view highlights that acquiring an understanding of assessment processes, criteria and standards needs active student participation. Within this context, a peer-assessed, weekly, assessment task was introduced in the first “serious” accounting subject offered as part of an undergraduate degree. The positive outcomes of this assessment innovation was that student failure rates declined 15%, tutorial participation increased fourfold, tutorial engagement increased six-fold and there was a 100% approval rating for the retention of the assessment task. In contributing to the core conference theme of “seismic” shifts within higher education, in stark contrast to the positive student response, staff-related issues of assessment conservatism and the necessity of meeting increasing research commitments, threatened the assessment task’s survival. These opposing forces to change have the potential to weaken the ability of higher education assessment arrangements to adequately serve either a new generation of students or the sector's community stakeholders.

Modeling key compromise impersonation attacks on group key exchange protocols

Two-party key exchange (2PKE) protocols have been rigorously analyzed under various models considering different adversarial actions. However, the analysis of group key exchange (GKE) protocols has not been as extensive as that of 2PKE protocols. Particularly, an important security attribute called key compromise impersonation (KCI) resilience has been completely ignored for the case of GKE protocols. Informally, a protocol is said to provide KCI resilience if the compromise of the long-term secret key of a protocol participant A does not allow the adversary to impersonate an honest participant B to A. In this paper, we argue that KCI resilience for GKE protocols is at least as important as it is for 2PKE protocols. Our first contribution is revised definitions of security for GKE protocols considering KCI attacks by both outsider and insider adversaries. We also give a new proof of security for an existing two-round GKE protocol under the revised security definitions assuming random oracles. We then show how to achieve insider KCIR in a generic way using a known compiler in the literature. As one may expect, this additional security assurance comes at the cost of an extra round of communication. Finally, we show that a few existing protocols are not secure against outsider KCI attacks. The attacks on these protocols illustrate the necessity of considering KCI resilience for GKE protocols.

Transferring knowledge through peer-reviewed assessment : the creation of a community of practice and the threats to its survival

While it is generally accepted in the learning and teaching literature that assessment is the single biggest influence on how students approach their learning, assessment methods within higher education are generally conservative and inflexible. Constrained by policy and accreditation requirements and the need for the explicit articulation of assessment standards for public accountability purposes, assessment tasks can fail to engage students or reflect the tasks students will face in the world of practice. Innovative assessment design can simultaneously deliver program objectives and active learning through a knowledge transfer process which increases student participation. This social constructivist view highlights that acquiring an understanding of assessment processes, criteria and standards needs active student participation. Within this context, a peer-assessed, weekly, assessment task was introduced in the first “serious” accounting subject offered as part of an undergraduate degree. The positive outcomes of this assessment innovation was that student failure rates declined 15%, tutorial participation increased fourfold, tutorial engagement increased six-fold and there was a 100% approval rating for the retention of the assessment task. In contributing to the core conference theme of “seismic” shifts within higher education, in stark contrast to the positive student response, staff-related issues of assessment conservatism and the necessity of meeting increasing research commitments, threatened the assessment task’s survival. These opposing forces to change have the potential to weaken the ability of higher education assessment arrangements to adequately serve either a new generation of students or the sector's community stakeholders.

A deductive system for proving workflow models from operational procedures

Many modern business environments employ software to automate the delivery of workflows; whereas, workflow design and generation remains a laborious technical task for domain specialists. Several differ- ent approaches have been proposed for deriving workflow models. Some approaches rely on process data mining approaches, whereas others have proposed derivations of workflow models from operational struc- tures, domain specific knowledge or workflow model compositions from knowledge-bases. Many approaches draw on principles from automatic planning, but conceptual in context and lack mathematical justification. In this paper we present a mathematical framework for deducing tasks in workflow models from plans in mechanistic or strongly controlled work environments, with a focus around automatic plan generations. In addition, we prove an associative composition operator that permits crisp hierarchical task compositions for workflow models through a set of mathematical deduction rules. The result is a logical framework that can be used to prove tasks in workflow hierarchies from operational information about work processes and machine configurations in controlled or mechanistic work environments.

Crowded Diphosphinomethane Ligands in Catalysis: [(R2PCH2PR′2-κ2P)-NiR″]+ Cations for Ethylene Polymerization without Activators

The preparation of a series of nickel dichloride complexes with bulky diphosphinomethane chelate ligands R2PCH2PR′2 is reported. Reaction with the appropriate Grignard reagent leads to the corresponding dimethyl and dibenzyl complexes. Cationic monomethyl and mono-η3-benzyl complexes are generated from these dialkyl complexes by protonation with [H(OEt2)2]+[B(3,5-(CF3)2C6H3)4]−, while the complex [(dtbpm κ2P)Ni(η3-CH(CH2Ph)Ph]+[B(3,5-(CF3)2C6H3)4]−is obtained from protonation of the Ni(0) olefin complex (dtbpm-κ2P)N(η2-trans-stilbene). Crystal structures of examples of dichlorides, dimethyl, dibenzyl, cationic methyl, and cationic η3-benzyl complexes are reported. Solutions of the cations polymerize ethylene under mild conditions and without the necessity of an activating agent, to form polyethylene having high molecular weights and low degrees of chain branching. In comparison to the Ni methyl cations, the η3-benzyl cation complexes are more stable and somewhat less active but still very efficient in C2H4 polymerization. The effect on the resulting polyethylene of varying the substituents R, R′ on the phosphine ligand has been examined, and a clear trend for longer chain PE with less branching in the presence of more bulky substituents on the diphosphine has been found. Density functional calculations have been used to examine the rapid suprafacial η3 to η3 haptotropic shift processes of the[(R2PCH2PR′2)Ni] fragment and the η3−η1 change of the coordination mode of the benzyl group required for polymerization in those cations.

Fuelling traffic : abolitionist claims of a causal nexus between legalised prostitution and trafficking

Over the last decade, researchers and legislators have struggled to get an accurate picture of the scale and nature of the problem of human trafficking. In the absence of reliable data, some anti-prostitution activists have asserted that a causal relationship exists between legalised prostitution and human trafficking. They claim that systems of legalised or decriminalised prostitution lead to increases in trafficking into the sex industry. This paper critically analyses attempts to substantiate this claim during the development of anti-trafficking policy in Australia and the United States. These attempts are explored within the context of persistent challenges in measuring the scale and nature of human trafficking. The efforts of abolitionist campaigners to use statistical evidence and logical argumentation are analysed, with a specific focus on the characterisation of demand for sexual services and systems of legalised prostitution as ‘pull’ factors fuelling an increase in sex trafficking. The extent to which policymakers sought to introduce evidence-based policy is also explored.

The investigation of design-build variants in the construction market of the People’s Republic of China

Design-Build (DB) system has been widely adopted overseas but it has not received the same popularity yet in the People’s Republic of China. The selection of design-build variant is regarded as one of the critical obstacles to the application of this alternative. This paper investigates categories of design-build variants in the construction market of China. The develop-and-construction, enhanced design-build, traditional-design-build and engineering procurement-construction (EPC) are the four current designbuild variants adopted by clients. Each of them is developed to meet a varying set of circumstances and has its own advantages and disadvantages. The develop-and-construction is mostly used in large, complex projects in housing industry and it will guarantee client’s great control over the project while still leave some design room for the contractor. The traditional-design-build and enhanced-design-build systems are mostly applied in projects that are comparatively simple, small-scale, and the DB contractors will have greater control of the projects. The EPC is the extension of pure design-build method and is widely adopted in the petrochemical, metallurgical and electronic fields because of the high-technique requirements and the necessity for one entity to control the design, construction, procurement and commissioning etc. Four corresponding design-build projects are also presented in this paper in order to better illustrate the operational process and provide the insight for understanding the design-build variants in Mainland China.

A superdirective 3-element array for adaptive beamforming

A small array composed of three monopole elements with very small element spacing on the order of λ/6 to λ/20 is considered for application in adaptive beamforming. The properties of this 3-port array are governed by strong mutual coupling. It is shown that for signal-to-noise maximization, it is not sufficient to adjust the weights to compensate for the effects of mutual coupling. The necessity for a RF-decoupling network (RF-DN) and its simple realization are shown. The array with closely spaced elements together with the RF-DN represents a superdirective antenna with a directivity of more than 10 dBi. It is shown that the required fractional frequency bandwidth and the available unloaded Q of the antenna and RF-DN structure determine the lower limit for the element spacing.