Secular changes in body dimensions of Royal Australian Air Force aircrew (1971–2005)

The aim of this study was to quantify the secular changes in body dimensions of Royal Australian Air Force aircrew. Following corrections for methodological differences, two samples (matched for age and overall body size) of male aircrew measured in 1971 (n = 220) and 2005 (n = 220) were compared across 13 absolute and proportional body dimensions. Changes in means were expressed as standardised effect sizes and changes in distributional characteristics were expressed as the ratio of coefficients of variation and as changes in skew. Small secular increases (standardised effects sizes >0.2) in age-matched aircrew were observed for mass, height, BMI, sitting height, buttock–knee length, waist girth, hip girth and waist:hip ratio, with a small decline observed for head girth. Changes in body dimensions were not independent of changes in overall body size (except for head girth) and were not always uniform across the distribution. These changes in body size have implications for ensuring correct human–machine and human–equipment fit.

Statement of Relevance: There have been small secular changes in body dimensions of RAAF aircrew between 1971 and 2005, although these secular changes have not always been uniform across the distribution. These secular changes in body dimensions have implications for ensuring correct human–machine and human–equipment fit and underscore the need for regular anthropometric surveys.     

A bibliometric retrospective of the Journal Computers in Human Behavior (1991–2015)

This study aims to create a bibliometric profile of the Journal Computers in Human Behavior employing bibliometric analysis, bibliometric mapping and thematic analysis to identify its document types, the dynamics and trends of research literature production, impact factor, most cited articles, and large contributing institutions and countries. Additionally, the authors were interested in finding the established patterns of cooperation among countries and institutions and the most productive research themes and their evolution through time. We were also interested in finding out if there are any sleeping beauties among articles published in the Journal. The study revealed a positive trend of scientific literature production and that the average number of references is increasing contrary to the number of pages per publication, which is decreasing, although it has remained stable in recent years. The most productive countries and institutions are from the United States, and the majority of the literature production is done by economically and scientifically fit and well developed countries. The identified research themes correspond with the Journal's aims and scope. The rising number of publications, increasing number of citations and, consequently, the Journal impact factor, together with the existence of sleeping beauties, shows that the editorial policy is well thought out and future oriented.     

A Formalization of the Knuth–Bendix(–Huet) Critical Pair Theorem

A mechanical proof of the Knuth–Bendix Critical Pair Theorem in the higher-order language of the theorem prover PVS is described. This well-known theorem states that a Term Rewriting System is locally confluent if and only if all its critical pairs are joinable. The formalization of this theorem follows Huet’s well-known structure of proof in which the restriction on strong normalization or Noetherian was dropped and the result presented as a lemma. In order to formalize the Knuth–Bendix Critical Pair Theorem we rely on previously developed PVS theories for abstract reduction systems, named ars, and term rewriting systems, named trs, which were built upon the PVS libraries for finite sequences and sets. On the one hand, the theory trs is composed of subtheories for dealing with the structure of terms, for replacements of subterms and substitutions and jointly with the theory ars it allows for adequate specifications of elaborate notions of term rewriting systems such as the one of critical pairs. On the other hand, ars specifies basic definitions and notions of abstract reduction systems such as reduction, termination, normal forms, and confluence as well as non basic concepts such as strong normalization.     

Particle swarm optimisation in designing parameters of manufacturing processes: A review (2008–2018)

The evolutionary optimisation algorithms appeared as an effective alternative to conventional statistical methods that have certain limitations in optimising complex manufacturing processes. Considering works published in the last decade, this paper presents an analysis of the particle swarm optimisation (PSO) implementation in designing parameters of heterogeneous manufacturing processes, both conventional and emerging, new processes. The literature review and analysis was structured according to the complexity of the optimisation problem (single response and multiresponse problems), and the development of an objective function for PSO. The tuning of the PSO algorithm-specific parameters was analysed in detail. The PSO algorithm performance was benchmarked with the results of other methods, including evolutionary algorithms, in designing process parameters. The concerns in applying PSO for multiresponse manufacturing problems were highlighted, and recommendations for future research were drawn. Such a comprehensive review on the PSO application in optimising manufacturing processes, including the detailed discussion on the algorithm characteristics and benchmark with other optimisation procedures, has not been pursued so far. Therefore, this review analysis provides hands on information for researchers and engineers at one place, and it is believed that the findings could serve as a basis for the future research and implementation directions.     

Expert system applications in business: A review and analysis of the literature (1977–1993)

A survey of expert system (ES) business application papers published between 1977 and 1993 indicates that an increasing amount of ES research is being conducted for a diverse range of business activities. The classification of literature by (1) year of publication, (2) application area, (3) generic problem area addressed, (4) problem domain, (5) level of management, (6) level of task interdependence, (7) means of development, (8) corporate/academic interaction in development, and (9) technology integration provides some insights in the trend. Implications to ES developers are discussed.     

Joint distribution of the number of vertices with given different outdegrees in Galton–Watson forest

A Galton–Watson forest consisting of N roots (or trees) and n   non-root vertices is considered. We study limit distributions of the number of vertices of a given outdegree in such a forest. In this work joint distribution of the number of vertices with the given different outdegrees _r1$r_1$ and _r2$r_2$ is considered. A local limit theorem for this characteristic is proved.     

A different way of seeing: Albert Borgmann’s philosophy of technology and human–computer interaction

Traditional human–computer interaction (HCI) allowed researchers and practitioners to share and rely on the ‘five E’s’ of usability, the principle that interactive systems should be designed to be effective, efficient, engaging, error tolerant, and easy to learn. A recent trend in HCI, however, is that academic researchers as well as practitioners are becoming increasingly interested in user experiences, i.e., understanding and designing for relationships between users and artifacts that are for instance affective, engaging, fun, playable, sociable, creative, involving, meaningful, exciting, ambiguous, and curious. In this paper, it is argued that built into this shift in perspective there is a concurrent shift in accountability that is drawing attention to a number of ethical, moral, social, cultural, and political issues that have been traditionally de-emphasized in a field of research guided by usability concerns. Not surprisingly, this shift in accountability has also received scarce attention in HCI. To be able to find any answers to the question of what makes a good user experience, the field of HCI needs to develop a philosophy of technology. One building block for such a philosophy of technology in HCI is presented. Albert Borgmann argues that we need to be cautious and rethink the relationship as well as the often-assumed correspondence between what we consider useful and what we think of as good in technology. This junction—that some technologies may be both useful and good, while some technologies that are useful for some purposes might also be harmful, less good, in a broader context—is at the heart of Borgmann’s understanding of technology. Borgmann’s notion of the device paradigm is a valuable contribution to HCI as it points out that we are increasingly experiencing the world with, through, and by information technologies and that most of these technologies tend to be designed to provide commodities that effortlessly grant our wishes without demanding anything in return, such as patience, skills, or effort. This paper argues that Borgmann’s work is relevant and makes a valuable contribution to HCI in at least two ways: first, as a different way of seeing that raises important social, cultural, ethical, and moral issues from which contemporary HCI cannot escape; and second, as providing guidance as to how specific values might be incorporated into the design of interactive systems that foster engagement with reality.     

Imperfect melting pot – Analysis of changes in diversity and segregation of US urban census tracts in the period of 1990–2010

Analyzing racial distribution and its temporal change in American urban areas is an active area of research. Most attention focused on assessing levels of racial segregation at the spatial scale of a metropolitan area. In this paper, we present an analysis of 1990–2010 changes to racial diversity and segregation on a much smaller spatial scale of an urban census tract. To access time-standardized racial information at the tract and at the census block scales we use multiyear compatible high-resolution population grids. Indices of racial diversity and segregation are calculated for over 30,000 tracts pooled from 41 metropolitan areas. Statistical analysis of this dataset reveals that during the 1990–2010 period urban tracts increased their diversity in line with diversity increases of entire metro areas, but unlike metros, they also increased their levels of segregation. We hypothesize that an increased tendency for the residences of people of the same race to spatially aggregate on the tract scale is the result of individuals exercising preferences regarding their neighbors in reaction to the nationwide increase in diversity of the American population. The study also re-derives diversity and segregation indices from the first principles of the information theory, highlights the need to think about the issue of racial diversity/segregation in terms of spatial patterns, and uses one-person-per-dot maps to connect diversity/segregation indices to actual racial patterns.     

Simultaneous self-verified computation of exp (A) and ∫ 0 1 exp (As) dsexp (As) ds

We propose a method for simultaneous computation of verified bounds for the matrix functions exp (A) and ∫ ₀ ¹ exp (As) ds where the inclusion of the integral is obtained during the computation of verified bounds for exp (A) at very little additional cost. Highly accurate results of our method are achieved by the use of advanced computer arithmetic and an implementation of dynamic precision by means of staggered correction representation.     

Analysis of the stabilities of hexameric amyloid-β(1-42) models using discrete molecular dynamics simulations

Amyloid-β (Aβ) oligomers appear to play a pivotal role in Alzheimer's disease. A 42 residue long alloform, Aβ42, is closely related to etiology of the disease. In vitro results show evidences of hexamers; however structures of these hexamers have not been resolved experimentally. Here, we use discrete molecular dynamics (DMD) to analyze long duration stabilities of Aβ42 hexamer models developed previously in our lab. The hydrophobic core of these models is a six-stranded β-barrel with 3-fold radial symmetry formed by residues 30-40. This core is shielded from water by residues 1-28. The nine models we analyzed differ by the relative positions of the core β-strands, and whether the other segments surrounding the core contain α helices or β-strands. A model of an annular protofibril composed of 36 Aβ peptides was also simulated. Results of these model simulations were compared with results of aggregation simulations that started from six well separated random coils of Aβ42 and with simulations of two known β-barrel structures. These results can be categorized into three groups: stable models with properties similar or superior to those of experimentally determined β-barrel proteins, aggregation-prone models, and an amorphous aggregate from random coils. Conformations at the end of the simulation for aggregation-prone models have exposed hydrophobic core with dangling β-strands on the surface. Hydrogen bond patterns within the β-barrel were a critical factor for stability of the β-barrel models. Aggregation-prone conformations imply that the association of these hexamers may be possible, which could lead to the formation of larger assemblies.     

Landsat mapping of annual inundation (1979–2006) of the Macquarie Marshes in semi-arid Australia

Measuring inundation over long timeframes is essential for understanding the responses of large floodplain wetlands on regulated rivers, such as the internationally Ramsar listed Macquarie Marshes (2000 km²) in central-eastern Australia. We used near-spring Landsat images (Multispectral Scanner (MSS) and Thematic Mapper (TM) imagery) over 28 years (1979–2006) and classified for inundation, integrating water and vegetation response using Iterative Self-Organizing Data Analysis (ISODATA) clustering. A spatially explicit inundation index showed that zones inundated with high frequency were mostly in the northern region. Change detection of inundation indices over three consecutive water management periods (period 1 (1979–1987), period 2 (1988–1996) and period 3 (1997–2006)) showed that zones inundated with high frequency across the Macquarie Marshes contracted, equating to the loss of three or more spring floods from each 9-year period, despite no corresponding change in annual catchment or local rainfall. Landsat represents the only effective available long-term information for analysing long-term changes in inundation patterns of floodplain wetlands.     

Petr Petrovich Troyanskii (1894–1950): A Forgotten Pioneer of Mechanical Translation

This article presents translations of works by Troyanskii describing his 1933 proposals for a mechanical translation device, some later elaborations of the linguistic and technical features, and also translated extracts from commentaries made in 1959 by the Russian editors of his papers. The paper includes extensive assessments of Troyanskii's proposals, and places his work in the context of his time and in the light of subsequent research in machine translation.     

Educational virtual environments: A ten-year review of empirical research (1999–2009)

This study is a ten-year critical review of empirical research on the educational applications of Virtual Reality (VR). Results show that although the majority of the 53 reviewed articles refer to science and mathematics, researchers from social sciences also seem to appreciate the educational value of VR and incorporate their learning goals in Educational Virtual Environments (EVEs). Although VR supports multisensory interaction channels, visual representations predominate. Few are the studies that incorporate intuitive interactivity, indicating a research trend in this direction. Few are the settings that use immersive EVEs reporting positive results on users’ attitudes and learning outcomes, indicating that there is a need for further research on the capabilities of such systems. Features of VR that contribute to learning such as first order experiences, natural semantics, size, transduction, reification, autonomy and presence are exploited according to the educational context and content. Presence seems to play an important role in learning and it is a subject needing further and intensive studies. Constructivism seems to be the theoretical model the majority of the EVEs are based on. The studies present real world, authentic tasks that enable context and content dependent knowledge construction. They also provide multiple representations of reality by representing the natural complexity of the world. Findings show that collaboration and social negotiation are not only limited to the participants of an EVE, but exist between participants and avatars, offering a new dimension to computer assisted learning. Little can yet be concluded regarding the retention of the knowledge acquired in EVEs. Longitudinal studies are necessary, and we believe that the main outcome of this study is the future research perspectives it brings to light.     

Modelling of the thermodynamic properties of the ABr–CeBr3 (A=Li–Cs ) systems

The thermodynamic properties of the ABr–CeBr₃ (A=Li–Cs) systems were assessed by the CALPHAD method. The liquid phase in the systems was described by the non-stoichiometric associate model. The entropies of mixing in the liquid ABr–CeBr₃ (A=Li,Na) systems are evaluated from experimental data. The entropies of mixing in the liquid ABr–CeBr₃ (A=K,Rb,Cs) systems, and the Gibbs energies of formation of pseudobinary compounds: A₃CeBr₆(s), A₂CeCl₅(s), ACe₂Cl₇(s) (A=K,Rb,Cs) were estimated due to the lack of experimental data. The presence of solid solution near NaBr was predicted from calculations. The nature of the liquid phase and precision of calculations were discussed.     

A computational approach of A ∞-(co)algebras

We present a computer program to compute the explicit structural components of an A _∞-(co)algebra deduced from a contraction, which is a special type of homotopy equivalence. The input is a contraction from a dg-(co)algebra to a simple dg-module and the output is a functional object that defines the operations {μ _i } _i≥1 (resp. {Δ _i } _i≥1) in the deduced A _∞-structure on the simple dg-module. We conclude with some concrete applications.     

Monitoring cropland changes along the Nile River in Egypt over past three decades (1984–2015) using remote sensing

The Nile River basin is the main agricultural area in Egypt. In recent decades, human activities and climate change have remarkably influenced the ecological environment there. Those changes have caused land degradation, sea level rise, and conflicts between land and population, threatening the agricultural system and food security of Egypt. In this study, cropland mapping along the Nile in Egypt over the past three decades (1984–2015) was conducted at annual frequency, using 961 Landsat TM/ETM+/OLI images. Spectral features of selected growing season images and band ratio-based indices were used in supervised classification. Thereafter, terrain and time series information were used to filter possible classification errors on the basis of logical judgment and statistical analysis. The average overall classification accuracy of cropland was greater than 90%. Furthermore, temporal and spatial characteristics of cropland expansion were analysed. The results highlight the annual geographical distribution of cropland dynamics from the Nile Valley to desert. In total, cropland areas had increased by 33.7% from 2848.1 kha in 1984 to 3807.8 kha in 2015, with an annual average increase of 31.0 kha in these 32 years.     

Optimization of sequences in CDMA systems: A statistical–mechanics approach

A statistical–mechanics approach is useful not only in analyzing the macroscopic system performance of wireless communication systems, but also in discussing design problems of wireless communication systems. We discuss a design problem of spreading sequences in code-division multiple-access (CDMA) systems, as an example demonstrating the usefulness of the statistical–mechanics approach. We analyze, via the replica method, the average mutual information between inputs and outputs of a randomly spread CDMA channel, and discuss the optimization problem with the average mutual information as the measure of optimization. It has been shown that the average mutual information is maximized by orthogonally-invariant random Welch bound equality (WBE) spreading sequences. This finding is an extension of the optimality of WBE spreading sequences with Gaussian inputs for non-Gaussian inputs.