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3D modelling has an important role in the design and manufacture of complex mechanical components, such as band brake systems, which are actuated by a pneumatic cylinder. This type of brake is commonly used in various industrial applications due to its efficiency in transmitting braking force and long-term reliability. By using modeling software such as Autodesk Inventor, designers can create detailed models of components and assemblies, allowing for accurate fit and function verification prior to actual manufacturing. This approach reduces the risk of design errors and ensures a final product optimized for performance and durability. This paper presents the graphic modeling process of a band brake system, actuated by a pneumatic cylinder, emphasizing the importance of using modern technologies in the industrial field. [ABSTRACT FROM AUTHOR]

Abstract: 3D modelling has an important role in the design and manufacture of complex mechanical components, such as band brake systems, which are actuated by a pneumatic cylinder. This type of brake is commonly used in various industrial applications due to its efficiency in transmitting braking force and long-term reliability. By using modeling software such as Autodesk Inventor, designers can create detailed models of components and assemblies, allowing for accurate fit and function verification prior to actual manufacturing. This approach reduces the risk of design errors and ensures a final product optimized for performance and durability. This paper presents the graphic modeling process of a band brake system, actuated by a pneumatic cylinder, emphasizing the importance of using modern technologies in the industrial field.

Introduction. The impact of microorganisms on the cement stone of concrete accelerates the removal of “free calcium hydroxide” from the pore structure and promotes the decomposition of calcium-containing phases, resulting in a decrease in the strength characteristics of concrete and further destruction. Biodegradation must be taken into account when determining the durability of concrete. Mathematical modelling makes it possible to predict its condition at any stage of the life cycle of a concrete product and to establish its remaining service life.Materials and methods. The effect of mass transfer parameters on changes in calcium hydroxide concentrations in concrete and on the intensity of its leaching into a liquid medium is shown graphically by the results of numerical modelling. The description of mass transfer processes in concrete biocorrosion was carried out using a developed mathematical model, which takes into account the influence of microorganisms and their waste products as an internal source of absorption or release of mass of “free calcium hydroxide” in concrete cement stone. The conditions for reaching the values of calcium hydroxide concentrations in cement stone corresponding to the beginning of decomposition of highly basic components are described by solving the mass transfer problem.Results. Based on the mathematical model describing the kinetics of mass transfer, a mathematical apparatus for predicting the degree of biodegradation of cement concrete was developed. Graphical dependences are presented, which are the result of a simulated numerical experiment, describing the effect of similarity criteria (Fourier, Bio) and a coefficient taking into account phase characteristics on the dynamics and kinetics of the mass transfer process during concrete biodegradation in a wide range of system parameters. The most intense change in the kinetics and dynamics of mass transfer occurs at the initial stages of exposure to the products of microorganisms during liquid corrosion of concrete.Conclusions. The obtained graphical dependences provide an understanding of the conditions for slowing down and intensifying mass transfer processes in the concrete – biofilm – liquid medium system. The engineering methodology of calculation of mass transfer parameters and service life of concrete is applicable at any stage of operation of reinforced concrete products and structures and makes it economically feasible to assign protective equipment and set the terms of their use.

Introduction. There is no concept of “life cycle of a building structure (building material)” in the available regulatory and scientific and technical literature. Since the duration of the life cycle of a real estate object largely depends on the durability of building structures and materials, it is reasonable to study the changes in the strength parameters of building structures during their life cycle. Graphical modelling of the life cycle of a building structure (building material) reflects the strength parameters of the structure at all stages of operation.Materials and methods. The methodology of the work is based on graphical modelling of the life cycle of a building structure. The relative value of compressive strength coefficient was chosen as an indicator of the concrete structure durability. The change of the compressive strength of concrete building structures can be determined according to the logarithmic law. The mathematical operator of the Cauchy problem, which consists in finding a solution to an ordinary differential equation of the first order, can be used to establish the state of a concrete structure at any period of the life cycle.Results. Graphical models of compressive strength behavior in time of the life cycle of a structure (building) are presented, showing the periods of formation of the concrete structure. The graphical model is supplemented with the period of time up to the moment corresponding to the achievement of the critical value of concrete strength, at which the structure collapses. The variants of changing the life cycle of the structure under the influence of external and internal factors are graphically depicted.Conclusions. The definition of the life cycle of a building structure (material) is proposed. The expediency of introducing the concept of “life cycle of a building structure (building material)” into regulatory documentation and scientific and technical literature is substantiated.

Using data from the sixth wave of the World Value Survey and operationalising a definition of national culture that emphasises both specific cultural traits and the inter-dependence among them, this paper proposes a methodology to reveal the latent network structure of every national culture and to measure the cultural distance associated with every pair of countries as a Jeffreys' divergence between copula graphical models. The two components of this new measure of cultural distance show different correlations with measures of geographical, historical, economic, and political distance among countries and with the similarity in the topologies of the countries cultural networks. [ABSTRACT FROM AUTHOR]

Model-Based Systems Engineers, particularly those moving from software to systems engineering, claim that SysML-like notations, which are symbolic two-dimensional diagrams made of boxes and lines, are domain-independent, thus very convenient to support the cross-functional design of a system architecture. However, the abstract diagramming syntax of MBSE notations makes their adoption difficult, especially by notational nonexperts, and using iconic graphics is one way of improvement. Very few studies attempted to replace 2D diagrams with immersive 3D visuals without objective evidence. We assume that it is due to a lack of quality criteria to compare 2D diagrams with 3D visuals. This paper will argue that human-centric 3D visuals should replace MBSE diagrams where appropriate. A new human-centric MBSE modelling environment motivates the adoption of interactive and immersive 3D visuals to facilitate communication and participation in multidisciplinary co-design activities from mission to concept definition. Our claim is not supported by measured evidence, but a functional demonstrator provides observed evidence and, compared to existing studies, we discuss our proposal based on the Physics of Notation. Future studies will concentrate on the modelling of the behavioural and structural views and the definition of criteria to validate the human-centric MBSE modelling environment. [ABSTRACT FROM AUTHOR]

To create a precise model structure and perform fault monitoring algorithms for a wide range of complex systems along with dynamic behavioural characteristics, the causal graph-based methods were considered herein. In this paper, a new scheme was devised based on fast fault detection mechanism relying on the Directed Hypergraph Observer model. The performance of the suggested pattern is illustrated by a case study including systems with single energy. Noting that the modern methods possess a large range of applications for the reliability and energy effectiveness analysis related to multi-energy systems. The Directed Hypergraph model architecture was exploited to generate the diagnostic condition based on a graphical observer.

We consider the problem of modelling restricted interactions between continuously-observed time series as given by a known static graph (or network) structure. For this purpose, we define a parametric multivariate Graph Ornstein-Uhlenbeck (GrOU) process driven by a general Lévy process to study the momentum and network effects amongst nodes, effects that quantify the impact of a node on itself and that of its neighbours, respectively. We derive the maximum likelihood estimators (MLEs) and their usual properties (existence, uniqueness and efficiency) along with their asymptotic normality and consistency. Additionally, an Adaptive Lasso approach, or a penalised likelihood scheme, infers both the graph structure along with the GrOU parameters concurrently and is shown to satisfy similar properties. Finally, we show that the asymptotic theory extends to the case when stochastic volatility modulation of the driving Lévy process is considered. [ABSTRACT FROM AUTHOR]

Spatio-temporal evolution of soil moisture is a complex process and controlled by several factors including hydro-meteorological forcings. This study borrows a recently developed concept of temporal networks to capture the time-varying association between hydro-meteorological forcings and spatio-temporal evolution of soil moisture. Climate change and dynamic terrestrial environment cause slow but continuous change in the characteristics of hydro-meteorological forcings leading to variation in spatio-temporal distribution of soil moisture. Keeping this in the focus of the study, temporal networks based time-varying modelling framework is adapted for one-month to one-season (three-months) in advance prediction of monthly soil moisture for entire Indian mainland. Results indicate that the association among the hydro-meteorological forcings varies with both space and time. With the increase in prediction lead-time, the strength of association with the variables, such as pressure, wind and temperature, decreases and that with the variables like leaf area index remains informative. Among different seasons, the model shows superior performance for the monsoon and post monsoon periods. Next, the soil moisture based extremes are assessed by utilizing two deficit indices and two wetness indices. The model performance is highly satisfactory but varies over space and seasons, with a marginally better performance for the wetness indices. Overall, given the vast spatial extent of the Indian mainland, the proposed model performs robustly for almost all the climatic regions and may be promising for other parts of the world as well. [ABSTRACT FROM AUTHOR]

This paper is about the use of the multiblock regression method sequential and orthogonalized partial least squares (SO‐PLS) for path modeling. The paper is a follow up of previously published papers on the same topic and presents a number of new results for the method. First of all, the paper discusses more thoroughly the aspect of how to incorporate blocks in the models and relates this to standard concepts in the area of graphical modeling. Second, the paper defines the concept of direct and indirect effects more precisely in terms of population parameters and shows how they are related to the additional effect in SO‐PLS modeling. The paper illustrates the theory by simple graphs, simulations, and a real example from process monitoring. In Section 2 we describe basic concepts in graphical modelling and in Section 4 we show how these concepts are linked to SO‐ PLS, which is described in Section 3. Section 5 is devoted to direct and additional effects and in Sections 7 and 8 are presented two examples, one simulated and one from process modelling. [ABSTRACT FROM AUTHOR]

To create a precise model structure and perform fault monitoring algorithms for a wide range of complex systems along with dynamic behavioural characteristics, the causal graph-based methods were considered herein. In this paper, a new scheme was devised based on fast fault detection mechanism relying on the Directed Hypergraph Observer model. The performance of the suggested pattern is illustrated by a case study including systems with single energy. Noting that the modern methods possess a large range of applications for the reliability and energy effectiveness analysis related to multi-energy systems. The Directed Hypergraph model architecture was exploited to generate the diagnostic condition based on a graphical observer. [ABSTRACT FROM AUTHOR]

Space sparsity, low amount of resources, maritimity, facility to recognize geographical and political frontiers, endemism and social differences in relation to other lands are some features of the islands. However, there are many situations related to the insular spaces and we chose the chorotypes (complex graphic models of spatial relationships common to two or more places on Earth) to show some possibilities to understand the insularity. To do so, we brought examples of islands and archipelagoes in Brazil and around the world.

Space sparsity, low amount of resources, maritimity, facility to recognize geographical and political frontiers, endemism and social differences in relation to other lands are some features of the islands. However, there are many situations related to the insular spaces and we chose the chorotypes (complex graphic models of spatial relationships common to two or more places on Earth) to show some possibilities to understand the insularity. To do so, we brought examples of islands and archipelagoes in Brazil and around the world.

The technological design of devices has a significant share in the industrial field and, therefore, any study that highlights, through concrete examples, the main issues regarding the design of devices used, especially in the machine building industry, is welcome. The paper presents three fixturing devices specialized for the drilling operation of some technical pieces encountered in the field of hydraulic drives - spool valve, fixing clamp and flange support ventilation self-cleaning filter system. Both the pieces and the devices were made with the help of Autodesk Inventor program, a software package that streamlines as concrete and precise as possible the 3D modeling of solids.

The technological design of devices has a significant share in the industrial field and, therefore, any study that highlights, through concrete examples, the main issues regarding the design of devices used, especially in the machine building industry, is welcome. The paper presents three fixturing devices specialized for the drilling operation of some technical pieces encountered in the field of hydraulic drives - spool valve, fixing clamp and flange support ventilation self-cleaning filter system. Both the pieces and the devices were made with the help of Autodesk Inventor program, a software package that streamlines as concrete and precise as possible the 3D modeling of solids. [ABSTRACT FROM AUTHOR]

Hydroforming processes have become increasingly popular in recent years, due to the increasing demand for light parts in various fields, such as the automotive, aircraft and aerospace industries. This technology is relatively new compared to other processing procedures, such as lamination, forging or stamping. This paper presents some basic concepts about hydroforming procedures, as well as 3D graphical modeling of a hydro-mechanical drawing die made in the Autodesk Inventor software program.

Hydroforming processes have become increasingly popular in recent years, due to the increasing demand for light parts in various fields, such as the automotive, aircraft and aerospace industries. This technology is relatively new compared to other processing procedures, such as lamination, forging or stamping. This paper presents some basic concepts about hydroforming procedures, as well as 3D graphical modeling of a hydro-mechanical drawing die made in the Autodesk Inventor software program. [ABSTRACT FROM AUTHOR]

Long‐lead prediction of summer monsoon rainfall in India is a challenging task, especially at finer spatial scale. The spatial variability in the long‐lead (one or two season in advance) prediction plays a vital role in planning of hydrological and agricultural aspects of the society. One of the major issues in this field is the climate‐induced time‐varying characteristics (non‐stationarity) that lead to a deteriorating model performance as the time passes by after the model calibration. This study proposes the use of time‐varying approaches in order to check such deteriorating performance over time. Considering the time‐varying association between Indian summer monsoon rainfall and large‐scale climatic indices (e.g., El Niño‐Southern Oscillation, Equatorial Indian Ocean Oscillation, North Atlantic Oscillation, Pacific Decadal Oscillation, and El Niño Modoki Index), a time‐varying approach based on hybrid graphical modelling (GM) and vine copula (GM‐Copula) is demonstrated for rainfall prediction over five homogeneous monsoon regions (HMRs) in India. The time‐varying characteristic is imparted in the GM‐Copula approach by recursively updating the model inputs and the corresponding model parameters at a regular time interval (τ) through recalibration. In the time‐varying framework, the parameter τ is referred to as optimum recurrence interval of model recalibration and it is identified as 5 years for the regions with moderate rainfall and 3 years for regions with above and below moderate rainfall. The developed time‐varying approach is able to yield reasonably good prediction performance (mean absolute percentage error being within 4–10% across HMRs) with a prediction lead time of 5 months. HMR‐wise seasonal rainfall predictions with such quality and lead time are expected to be highly useful. [ABSTRACT FROM AUTHOR]

Highly pathogenic avian influenza (HPAI) subtype H5N8 outbreaks occurred in poultry farms in France in 2016–2017, resulting in significant economic losses and disruption to the poultry industry. Current evidence on associations between actual on‐farm biosecurity risk factors and H5N8 occurrence is limited. Therefore, a retrospective matched case–control study was undertaken to investigate the inter‐relationships between on‐farm biosecurity practices and H5N8 infection status to provide new insights regarding promising targets for intervention. Data were collected on 133 case and 133 control duck farms (i.e. the most affected species) located in one area of the country that was mostly affected by the disease. Data were analysed using Additive Bayesian Networks which offer a rich modelling framework by graphically illustrating the dependencies between variables. Factors indirectly and directly positively associated with farm infection were inadequate management of vehicle movements (odds ratio [OR] 9.3, 95% credible interval [CI] 4.0–22.8) and inadequate delimitation of farm and units (OR 3.0, 95% CI 1.6–5.8), respectively. Inadequate disposal of dead birds was instead negatively associated with the outcome (OR 0.1, 95% CI 0.0–0.3). The findings highlight that reinforcing farm access control systems and reducing the number of visitors are key biosecurity measures to control farm vulnerability to H5N8 infection and could help setting priorities in biosecurity practices to prevent outbreaks' re‐occurrence. [ABSTRACT FROM AUTHOR]

Summary: Mixed probit models are widely applied in many fields where prediction of a binary response is of interest. Typically, the random effects are assumed to be independent but this is seldom so for many real applications. In the credit risk application that is considered in the paper, random effects are present at the level of industrial sectors and they are expected to be correlated because of interfirm credit links inducing dependences in the firms' risk to default. Unfortunately, existing inferential procedures for correlated mixed probit models are computationally very intensive already for a moderate number of effects. Borrowing from the literature on large network inference, we propose an efficient expectation–maximization algorithm for unconstrained and penalized likelihood estimation and derive the asymptotic standard errors of the estimates. An extensive simulation study shows that the approach proposed enjoys substantial computational gains relative to standard Monte Carlo approaches, while still providing accurate parameter estimates. Using data on nearly 64000 accounts for small and medium‐sized enterprises in the UK in 2013 across 13 industrial sectors, we find that accounting for network effects via a correlated mixed probit model increases significantly the default prediction power of the model compared with conventional default prediction models, making efficient inferential procedures for these models particularly useful in this field. [ABSTRACT FROM AUTHOR]

Proton Exchange Membrane (PEM) water electrolysis system is one of the promising technologies to produce green hydrogen from renewable energy sources (wind and solar). However, performance and dynamic analysis of PEM water electrolysis systems are challenging due to the intermittent nature of such sources and involved multi-physical behaviour of the components and subsystems. This study proposes a generic dynamical model of the PEM electrolysis system represented in a modular fashion using Bond Graph (BG) as a unified modelling approach. Causal and functional properties of the BG facilitate the formal PEM electrolyser model to adapt and to fit the different configurations of the electrolyser ranging from laboratory scale to industrial scale. The system-specific key parameter values are identified optimally for a laboratory-scale electrolyser system running on a multi-source energy platform using experimental data. The mean absolute percentage error between simulation and experimental data is found to be less than 5%. The performance characteristic curves of the electrolyser are predicted at different operating temperatures using the identified key parameters. The predicted performance is in good agreement with the expected behaviour of the electrolyser found in the literature. The model also estimates the different energy losses and the real-time efficiency of the system under dynamic inputs. With these capabilities, the developed model provides an economical mean for design, control, and diagnosis development of such systems.

Networks with a very large number of nodes appear in many application areas and pose challenges for traditional Gaussian graphical modelling approaches. In this paper, we focus on the estimation of a Gaussian graphical model when the dependence between variables has a block-wise structure. We propose a penalized likelihood estimation of the inverse covariance matrix, also called Graphical LASSO, applied to block averages of observations, and we derive its asymptotic properties. Monte Carlo experiments, comparing the properties of our estimator with those of the conventional Graphical LASSO, show that the proposed approach works well in the presence of block-wise dependence structure and that it is also robust to possible model misspecification. We conclude the paper with an empirical study on economic growth and convergence of 1,088 European small regions in the years 1980 to 2012. While requiring a priori information on the block structure - e.g. given by the hierarchical structure of data - our approach can be adopted for estimation and prediction using very large panel data sets. Also, it is particularly useful when there is a problem of missing values and outliers or when the focus of the analysis is on out-of-sample prediction. [ABSTRACT FROM AUTHOR]

EMF and GMF are powerful frameworks for implementing tool support for modelling languages in Eclipse. However, with power comes complexity, implementing a graphical editor for a modelling language using EMF and GMF requires developers to handcraft and maintain several detailed interconnected models through a loosely guided, labour-intensive, and error-prone process. We demonstrate how the application of metamodel annotation and model transformation techniques can help to manage the complexity of GMF and EMF and deliver significant productivity, quality, and maintainability benefits. We present Eugenia, an open-source tool that implements the proposed approach, illustrate its functionality with an example, evaluate it through an empirical study, and report on the community's response to the tool. [ABSTRACT FROM AUTHOR]

A learning path has been developed on system dynamical graphical modelling, integrated into the Dutch lower secondary physics curriculum. As part of the developmental research for this learning path, students' understanding of the relation structures shown in the diagrams of graphical system dynamics based models has been investigated. One of our main findings is that only some students understand these structures correctly. Reality-based interpretation of the diagrams can conceal an incorrect understanding of diagram structures. As a result, students seemingly have no problems interpreting the diagrams until they are asked to construct a graphical model. Misconceptions have been identified that are the consequence of the fact that the equations are not clearly communicated by the diagrams or because the icons used in the diagrams mislead novice modellers. Suggestions are made for improvements. [ABSTRACT FROM AUTHOR]

While most countries are experiencing stable or declining rates of generalized trust, this has not been the case in the Nordic countries, where levels of generalized trust have continued to increase. In the Danish case, trust increased by 50 per cent in the period from 1981 to 2008. This article investigates this puzzling development by testing the dominant socialization, status, and institutional theories on trust development. Using the Danish 1990, 1999, and 2008 waves of the European Values Study Denmark, the author employs graphical modelling in analysing the drivers of generalized trust increase in Denmark. Graphical modelling allows hierarchical structures of independent variables and is robust to thin cells, thus giving a more detailed picture than conventional regression techniques. The study shows that socialization has had little impact on the increasing level of generalized trust, whereas both individual achievement and the generally increasing levels of affluence and education are important drivers of the trust increase. However, since large parts of the population reaped the benefits of increasing levels of education and employment in Denmark during this period, this is not just a case of increasing trust, but also one of a diminishing low-trust minority excluded from partaking in this development.

This article presents a structured and systematic approach for identifying and modelling compliance risks. The sophistication with which modern business is carried out and the unprecedented access to a global market means that businesses are exposed to increasing and diverse regulatory requirements in and across jurisdictions. Compliance with such requirements is practically challenging, partly due to the complexity of regulatory environments. One possibility in this regard is a risk-based approach to compliance, where resources are allocated to those compliance issues that are most risky. Despite the need for risk-based compliance, few specific methods and techniques for identifying and modelling compliance risks have been developed. Due to the lack of methodological and tool support, compliance risk identification often involves unstructured brainstorming, with uncertain outcomes. The proposed approach consists of a five-step process for the structured identification and assessment of compliance risks. This process aims at facilitating the identification of compliance risks and their documentation in a consistent and reusable fashion. As part of the process, the article provides a systematic approach for a graphical modelling of compliance risks, which aims at facilitating communication among experts from different backgrounds. The creation of graphical models can be partly automated based on natural language patterns for regulatory requirements. Furthermore, the structuring of the compliance requirement in a template aims at simplifying the modelling of compliance risks and facilitating a potential future automated model. [ABSTRACT FROM AUTHOR]

Purpose – This paper aims to show the associations between the amount of voluntary human capital (HC) disclosures and company profiles, including required HC and accounting information to verify a disclosure theory that consolidates four traditional theories. It also verifies the previously found association between voluntary HC information and share price. Design/methodology/approach – This research uses regression analysis and graphical modelling of a stratified random sample from the Tokyo Stock Exchange. Text mining software is used for content analysis of annual reports to quantify the amount of qualitative HC information. Findings – This study finds associations between the amount of voluntary HC information and the number of employees and the average salary. In particular, information about competence/qualification and personnel are related. Research limitations/implications – The results provide some support for the consolidated theory and are presumably consistent with the signalling theory and stakeholder theory in terms of the labour market rather than the financial market. Originality/value – By using both regression analysis and, graphical modelling this study shows the difference between the outputs of Germany and Japan and how HC characteristics of a firm relate to its disclosure behaviour, revealing hidden aspects that traditional prior studies have ignored. [ABSTRACT FROM AUTHOR]

The issue of transport in Martinique remains in many cases the countries of the region a decisive and crucial issue facing internal mobility increasingly prone to saturation exacerbated by the territorial configuration on the one hand, but also modes of use of the vehicle more and more systematic in the light of deficiencies in the provision of transport. This contribution aims to highlight the factors of the guiding principles of the space organization, by the same failures of the transport system on the island, and that the consequences in terms of environment.

The aim of this paper is to demonstrate how graphical chain models can be used as effective tools in life course research focusing in particular on models for longitudinal prospective data. The substantive research question focuses on whether young motherhood is a pathway through which socio-economic disadvantage in childhood is related to poor self-reported health in adulthood among the 1970 British birth cohort. By breaking down large multivariate systems into simpler more tractable subcomponents and analysing them via local regressions, graphical models help the understanding of complicated life course processes, show the intermediate relationships between predictors, and aid the understanding of the mechanisms through which potential confounding and mediating factors affect the outcome of interest. [ABSTRACT FROM AUTHOR]

The paper discusses a range of modern time series methods that have become popular in the past 20 years and considers their usefulness for cliometrics research both in theory and via a range of applications. Issues such as, spurious regression, unit roots, cointegration, persistence, causality, structural time series methods, including time varying parameter models, are introduced as are the estimation and testing implications that they involve. Applications include a discussion of the timing and potential causes of the British Industrial Revolution, income 'convergence' and the long-run behaviour of English real wages 1264-1913. Finally some new and potentially useful developments are discussed including the mildly explosive processes; graphical modelling and long memory. [ABSTRACT FROM AUTHOR]

A result for the equivalence of conditional independence graphs of ordered and unordered vector random variables from first-order Markov models is extended to arbitrary forests. The result is relevant to estimating graphical models for linkage disequilibrium between genetic loci. It explains why, in terms of the conditional independence structure, it sometimes does not matter whether you consider haplotypes or genotypes. [ABSTRACT FROM PUBLISHER]

We consider variable selection in high-dimensional linear models where the number of covariates greatly exceeds the sample size. We introduce the new concept of partial faithfulness and use it to infer associations between the covariates and the response. Under partial faithfulness, we develop a simplified version of the pc algorithm (Spirtes et al., 2000), which is computationally feasible even with thousands of covariates and provides consistent variable selection under conditions on the random design matrix that are of a different nature than coherence conditions for penalty-based approaches like the lasso. Simulations and application to real data show that our method is competitive compared to penalty-based approaches. We provide an efficient implementation of the algorithm in the R-package pcalg. [ABSTRACT FROM PUBLISHER]

Understanding patterns of morphological variation and their evolutionary causes is among the main goals of evolutionary biology. In this paper we analyse the pattern of morphological variation in the hyperdiverse ant genus Pheidole (Hymenoptera: Formicidae). We describe the morphospace defined by 231 Pheidole species in the New World using 18 linear quantitative characters. The first ordination axis of the morphospace was found to mainly reflect differences in body size, which explained 83.2 and 78.6% of all morphological variation in minor and major worker subcastes, respectively. Therefore, despite considerable morphological divergence among Pheidole species, most of this variation can be attributed to allometric changes along a size axis, leaving little opportunity for ecological specialization that might be reflected in the studied morphological traits. Simulations suggest that this degree of concentration of variance on the first principal component is unlikely to be due solely to shared phylogenetic history. The second ordination axis reflected mostly variation in head characters, most notably antennal scape length. The third ordination axis described aspects of alitrunk and petiole shape. Although generally concordant, the loading patterns in the second and third axes differed between minors and majors, suggesting different selective pressures affecting the evolution of each subcaste. These general trends in shape were confirmed by additional analyses that corrected for body size. Ordination analyses were complemented by comparing patterns of interspecific morphological covariation in minors and majors of Pheidole using newly developed analyses based on the statistical concept of conditional independence of Magwene. A comparison between worker subcastes indicated substantial reorganization in the pattern of character covariation, particularly through a decrease in character-correlation levels (dissociation). Moreover, graphical modelling indicated correlations between characters in widely different parts of the body, suggesting that the opportunity for morphological evolution in Pheidole appears to be surprisingly limited. This result might explain why morphological evolution in Pheidole has been highly conservative in spite of substantial ecological diversification. [ABSTRACT FROM AUTHOR]

Kansei quality varies with the individual. Therefore, when building a structural model of Kansei quality, it is very important to identify some essential structures by analysing individual differences. In this paper, the semantic differential method is used to improve steering wheel grip comfort. Assuming a hierarchical structural model of the steering wheel grip comfort, the individual differences are analysed using principal component analysis, and then some hierarchical structural models are built using graphical modelling. As a result, two remarkably different structures are built. Some guidelines for developing steering wheel production can be shown by comparing the different structures. [ABSTRACT FROM AUTHOR]

Abstract: Fortnightly observations of water quality parameters, discharge and water temperature along the River Elbe have been subjected to a multivariate data analysis. In a previous study [Petersen, W., Bertino, L., Callies, U., Zorita, E., 2001. Process identification by principal component analysis of river-quality data. Ecol. Model. 138, 193–213] applied principal component analysis (PCA) to show that 60% of variability in the data set can be explained through just two linear combinations of eight original variables. In the present paper more advanced multivariate methods are applied to the same data set, which are supposed to suit better interpretations in terms of the underlying system dynamics. The first method, graphical modelling, represents interaction structures in terms of a set of conditional independence constraints between pairs of variables given the values of all other variables. Assuming data from a multinormal distribution conditional independence constraints are expressed by zero partial correlations. Different graphical structures with nodes for each variable and connecting edges between them can be assessed with regard to their likelihood. The second method, canonical correlation analysis (CCA), is applied for studying the correlation structures of external forcing and water quality parameters. Results of CCA turn out to be consistent with the dominant patterns of variability obtained from PCA. The percentages of variability explained by external forcing, however, are estimated to be smaller. Fitting graphical models allows a more detailed representation of interaction structures. For instance, for given discharge and temperature correlated variations of the concentrations of oxygen and nitrate, respectively, can be modelled as being mediated by variations of pH, which is a representer for algal activity. Considerably simplified graphical models do not much affect the outcomes of both PCA and CCA, and hence it is concluded that these graphical models successfully represent the main interaction structures represented by the covariance matrix of the data. The analysed conditional independence patterns provide constraints to be satisfied by directed probabilistic networks, for instance. [Copyright &y& Elsevier]