Showing papers by "University of Maribor published in 2012"
Wellcome Trust Sanger Institute1, Broad Institute2, University of Groningen3, University of Pittsburgh4, Cedars-Sinai Medical Center5, Yale University6, University of Cambridge7, University of Chicago8, Harvard University9, Katholieke Universiteit Leuven10, University of Liège11, King's College London12, Université de Montréal13, New Jersey Institute of Technology14, Cleveland Clinic15, Peninsula College of Medicine and Dentistry16, Université libre de Bruxelles17, Aarhus University18, University of Adelaide19, University of Kiel20, Flinders University21, McGill University22, Ludwig Maximilian University of Munich23, Charité24, Icahn School of Medicine at Mount Sinai25, University of Bonn26, Karolinska Institutet27, Torbay Hospital28, University of Auckland29, Christchurch Hospital30, Imperial College London31, Queen's University32, University of Oslo33, Lithuanian University of Health Sciences34, Emory University35, Casa Sollievo della Sofferenza36, Ghent University37, University of Western Australia38, University of Edinburgh39, Queensland Health40, Newcastle University41, University of Dundee42, University of Manchester43, University of Amsterdam44, University of Maribor45, Royal Hospital for Sick Children46, Guy's and St Thomas' NHS Foundation Trust47, QIMR Berghofer Medical Research Institute48, Norfolk and Norwich University Hospital49, Leiden University50, Technische Universität München51, University of Toronto52, University of Pennsylvania53, Johns Hopkins University54, University of Queensland55
TL;DR: A meta-analysis of Crohn’s disease and ulcerative colitis genome-wide association scans is undertaken, followed by extensive validation of significant findings, with a combined total of more than 75,000 cases and controls.
Abstract: Crohn's disease and ulcerative colitis, the two common forms of inflammatory bowel disease (IBD), affect over 2.5 million people of European ancestry, with rising prevalence in other populations. Genome-wide association studies and subsequent meta-analyses of these two diseases as separate phenotypes have implicated previously unsuspected mechanisms, such as autophagy, in their pathogenesis and showed that some IBD loci are shared with other inflammatory diseases. Here we expand on the knowledge of relevant pathways by undertaking a meta-analysis of Crohn's disease and ulcerative colitis genome-wide association scans, followed by extensive validation of significant findings, with a combined total of more than 75,000 cases and controls. We identify 71 new associations, for a total of 163 IBD loci, that meet genome-wide significance thresholds. Most loci contribute to both phenotypes, and both directional (consistently favouring one allele over the course of human history) and balancing (favouring the retention of both alleles within populations) selection effects are evident. Many IBD loci are also implicated in other immune-mediated disorders, most notably with ankylosing spondylitis and psoriasis. We also observe considerable overlap between susceptibility loci for IBD and mycobacterial infection. Gene co-expression network analysis emphasizes this relationship, with pathways shared between host responses to mycobacteria and those predisposing to IBD.
4,094 citations
TL;DR: An overview of the definitions and units of measurement associated with environmental, social, and economic footprints is presented in this paper, where composite footprints combining two or more individual footprints are also assessed.
726 citations
TL;DR: It is shown that even a minute initial fraction of cooperators may be sufficient to eventually secure a highly cooperative final state, and it is found that the proposed win-stay-lose-learn rule promotes the evolution of cooperation very robustly and independently of the initial conditions.
Abstract: Holding on to one's strategy is natural and common if the later warrants success and satisfaction. This goes against widespread simulation practices of evolutionary games, where players frequently consider changing their strategy even though their payoffs may be marginally different than those of the other players. Inspired by this observation, we introduce an aspiration-based win-stay-lose-learn strategy updating rule into the spatial prisoner's dilemma game. The rule is simple and intuitive, foreseeing strategy changes only by dissatisfied players, who then attempt to adopt the strategy of one of their nearest neighbors, while the strategies of satisfied players are not subject to change. We find that the proposed win-stay-lose-learn rule promotes the evolution of cooperation, and it does so very robustly and independently of the initial conditions. In fact, we show that even a minute initial fraction of cooperators may be sufficient to eventually secure a highly cooperative final state. In addition to extensive simulation results that support our conclusions, we also present results obtained by means of the pair approximation of the studied game. Our findings continue the success story of related win-stay strategy updating rules, and by doing so reveal new ways of resolving the prisoner's dilemma.
533 citations
TL;DR: The observation of two narrow structures in the mass spectra of the π(±)Υ(nS) and π (±)h(b)(mP) pairs that are produced in association with a single charged pion in Υ(5S) decays is reported.
Abstract: We report the observation of two narrow structures in the mass spectra of the pi(+/-) Y(nS) (n = 1, 2, 3) and pi(+/-) h(b)(mP) (m = 1, 2) pairs that are produced in association with a single charged pion in Y(5S) decays The measured masses and widths of the two structures averaged over the five final states are M-1 = (10 6072 +/- 20) MeV/c(2), Gamma(1) =(184 +/- 24) MeV, and M-2 = (10 6522 +/- 15) MeV/c(2), Gamma(2) = (115 +/- 22) MeV The results are obtained with a 1214 fb(-1) data sample collected with the Belle detector in the vicinity of the Y(5S) resonance at the KEKB asymmetric-energy e(+)e(-) collider
492 citations
TL;DR: It is found that the stronger the bias in the utility function, the higher the level of public cooperation and cooperation is promoted because the aggressive invasion of defectors is more sensitive to the slowing-down than the build-up of collective efforts in sizable groups.
Abstract: We study the evolution of public cooperation on two interdependent networks that are connected by means of a utility function, which determines to what extent payoffs in one network influence the success of players in the other network. We find that the stronger the bias in the utility function, the higher the level of public cooperation. Yet the benefits of enhanced public cooperation on the two networks are just as biased as the utility functions themselves. While cooperation may thrive on one network, the other may still be plagued by defectors. Nevertheless, the aggregate level of cooperation on both networks is higher than the one attainable on an isolated network. This positive effect of biased utility functions is due to the suppressed feedback of individual success, which leads to a spontaneous separation of characteristic time scales of the evolutionary process on the two interdependent networks. As a result, cooperation is promoted because the aggressive invasion of defectors is more sensitive to the slowing-down than the build-up of collective efforts in sizable groups.
354 citations
TL;DR: Anatomic double-bundle ACL reconstruction is significantly superior to conventional single-b Bundle ACL reconstruction and better than anatomic single- bundle reconstruction.
Abstract: Background: Three different techniques of anterior cruciate ligament (ACL) reconstruction—conventional (transtibial) single bundle (CSB), anatomic single bundle (ASB), and anatomic double bundle (ADB)—have been described.Purpose: To determine if double-bundle reconstruction is needed to restore rotational stability or if anatomic placement of a single bundle can yield similar results.Study Design: Randomized controlled trial; Level of evidence, 1.Methods: From December 2005 to December 2007, 320 patients were prospectively randomized into 3 groups: ADB, ASB, and CSB reconstruction. The average follow-up was 51.15 months (range, 39-63 months). At the final follow-up, 281 patients were available. In all groups, hamstring tendons were used with suspensory fixation on the femoral side and bioabsorbable interference screw fixation on the tibial side. The outcomes were evaluated by an independent blinded observer using the Lysholm score and subjective International Knee Documentation Committee (IKDC) form. The ...
303 citations
TL;DR: Recently, a series of new monomers and polymerization mechanisms has been applied to the templating of high internal phase emulsions (HIPEs) providing a route to hierarchically porous materials with a range of functionalities and applications.
Abstract: Recently, a series of new monomers and polymerization mechanisms has been applied to the templating of high internal phase emulsions (HIPEs) providing a route to hierarchically porous materials with a range of functionalities and applications The high degree of control over the pore size is another attractive feature of these materials Usually, the continuous phase contains monomers, the droplet phase is used to template the large, primary pores, which are interconnected by secondary pores The addition of nonpolymerizable components to the continuous phase can result in phase separation during polymerization and tertiary pores Applications include polymer supports for catalysis and synthesis, separation and filtration, cell culture media, enzyme supports, and structural and isolation applications
276 citations
TL;DR: An efficient optimization algorithm called teaching–learning-based optimization (TLBO) is proposed in this article to solve continuous unconstrained and constrained optimization problems and the results show the better performance of the proposed algorithm.
Abstract: An efficient optimization algorithm called teaching–learning-based optimization (TLBO) is proposed in this article to solve continuous unconstrained and constrained optimization problems. The proposed method is based on the effect of the influence of a teacher on the output of learners in a class. The basic philosophy of the method is explained in detail. The algorithm is tested on 25 different unconstrained benchmark functions and 35 constrained benchmark functions with different characteristics. For the constrained benchmark functions, TLBO is tested with different constraint handling techniques such as superiority of feasible solutions, self-adaptive penalty, ϵ-constraint, stochastic ranking and ensemble of constraints. The performance of the TLBO algorithm is compared with that of other optimization algorithms and the results show the better performance of the proposed algorithm.
267 citations
TL;DR: The ultimate goal of this paper is to provide reminders for metaheuristics' researchers and practitioners in order to avoid similar mistakes regarding both the qualitative and quantitative aspects, and to allow fair comparisons of the TLBO algorithm to be made with other metaheuristic algorithms.
249 citations
TL;DR: The annual growth fluctuations of word use has a decreasing trend as the corpus size increases, indicating a slowdown in linguistic evolution following language expansion.
Abstract: We analyze the occurrence frequencies of over 15 million words recorded in millions of books published during the past two centuries in seven different languages. For all languages and chronological subsets of the data we confirm that two scaling regimes characterize the word frequency distributions, with only the more common words obeying the classic Zipf law. Using corpora of unprecedented size, we test the allometric scaling relation between the corpus size and the vocabulary size of growing languages to demonstrate a decreasing marginal need for new words, a feature that is likely related to the underlying correlations between words. We calculate the annual growth fluctuations of word use which has a decreasing trend as the corpus size increases, indicating a slowdown in linguistic evolution following language expansion. This “cooling pattern” forms the basis of a third statistical regularity, which unlike the Zipf and the Heaps law, is dynamical in nature.
234 citations
TL;DR: In this paper, a new strategy for the functionalization of chitosan with caffeic acid (CA) or gallic acid(GA) using laccase from Trametes versicolor is presented, yielding a product with modulated antioxidant and antimicrobial properties.
TL;DR: A new method for the automatic generation of digital terrain models from LiDAR data that correctly determines DTM even in those cases of more difficult terrain features, and parameter-free ground point filtering is achieved by automatic thresholding based on standard deviation.
Abstract: This paper considers a new method for the automatic generation of digital terrain models from LiDAR data. The method iterates a thin plate spline interpolated surface towards the ground, while points’ residuals from the surface are inspected at each iteration, with a gradually decreasing window size. Top-hat transformation is used to enhance discontinuities caused by surface objects. Finally, parameter-free ground point filtering is achieved by automatic thresholding based on standard deviation. The experiments show that this method correctly determines DTM even in those cases of more difficult terrain features. The expected accuracy of ground point determination on those datasets commonly used in practice today is over 96%, while the average total error produced on the ISPRS benchmark dataset is under 6%.
TL;DR: In this article, a multi-criteria optimisation of regional biomass supply chains for the conversion of biomass to energy through the simultaneous maximisation of economic performance and minimisation of the environmental and social FPs (footprints) is presented.
TL;DR: This work introduces a spatial ultimatum game with discrete strategies, and shows that this simple alteration opens the gate to fascinatingly rich dynamical behavior.
Abstract: Experiments on the ultimatum game have revealed that humans are remarkably fond of fair play. When asked to share an amount of money, unfair offers are rare and their acceptance rate small. While empathy and spatiality may lead to the evolution of fairness, thus far considered continuous strategies have precluded the observation of solutions that would be driven by pattern formation. Here we introduce a spatial ultimatum game with discrete strategies, and we show that this simple alteration opens the gate to fascinatingly rich dynamical behavior. In addition to mixed stationary states, we report the occurrence of traveling waves and cyclic dominance, where one strategy in the cycle can be an alliance of two strategies. The highly webbed phase diagram, entailing continuous and discontinuous phase transitions, reveals hidden complexity in the pursuit of human fair play.
TL;DR: It is found that sparsity may favor the resolution of social dilemmas, especially if the population density is close to the percolation threshold of the underlying graph.
Abstract: Spatial reciprocity is a well known tour de force of cooperation promotion. A thorough understanding of the effects of different population densities is therefore crucial. Here we study the evolution of cooperation in social dilemmas on different interaction graphs with a certain fraction of vacant nodes. We find that sparsity may favor the resolution of social dilemmas, especially if the population density is close to the percolation threshold of the underlying graph. Regardless of the type of the governing social dilemma as well as particularities of the interaction graph, we show that under pairwise imitation the percolation threshold is a universal indicator of how dense the occupancy ought to be for cooperation to be optimally promoted. We also demonstrate that myopic updating, due to the lack of efficient spread of information via imitation, renders the reported mechanism dysfunctional, which in turn further strengthens its foundations.
TL;DR: In this paper, the pion transition form factor, F(Q(2)), is measured for the kinematical region 4 GeV2 <= Q(2) <= 40 GeV 2, where -Q 2 is the invariant-mass squared of a virtual photon.
Abstract: We report a measurement of the process gamma gamma* -> pi(0) with a 759 fb(-1) data sample recorded with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The pion transition form factor, F(Q(2)), is measured for the kinematical region 4 GeV2 <= Q(2) <= 40 GeV2, where -Q(2) is the invariant-mass squared of a virtual photon. The measured values of Q(2)vertical bar F(Q(2))vertical bar agree well with the previous measurements below Q(2) similar or equal to 9 GeV2 but do not exhibit the rapid growth in the higher Q(2) region seen in another recent measurement, which exceeds the asymptotic QCD expectation by as much as 50%.
TL;DR: In this paper, phase diagrams and the analysis of emerging spatial patterns are used to demonstrate that adaptive punishment promotes public cooperation through the invigoration of spatial reciprocity, the prevention of the emergence of cyclic dominance, or the provision of competitive advantages to those that sanction antisocial behavior.
Abstract: Cooperation is crucial for the remarkable evolutionary success of the human species. Not surprisingly, some individuals are willing to bear additional costs in order to punish defectors. Current models assume that, once set, the fine and cost of punishment do not change over time. Here we show that relaxing this assumption by allowing players to adapt their sanctioning efforts in dependence on the success of cooperation can explain both the spontaneous emergence of punishment and its ability to deter defectors and those unwilling to punish them with globally negligible investments. By means of phase diagrams and the analysis of emerging spatial patterns, we demonstrate that adaptive punishment promotes public cooperation through the invigoration of spatial reciprocity, the prevention of the emergence of cyclic dominance, or the provision of competitive advantages to those that sanction antisocial behavior. The results presented indicate that the process of self-organization significantly elevates the effectiveness of punishment, and they reveal new mechanisms by means of which this fascinating and widespread social behavior could have evolved.
TL;DR: It is found that low levels of reliability tend to destroy synchronization and, moreover, that interneuronal networks with long inhibitory synaptic delays require a minimal level of reliability for the mixed oscillatory pattern to be maintained.
Abstract: Networks of fast-spiking interneurons are crucial for the generation of neural oscillations in the brain. Here we study the synchronous behavior of interneuronal networks that are coupled by delayed inhibitory and fast electrical synapses. We find that both coupling modes play a crucial role by the synchronization of the network. In addition, delayed inhibitory synapses affect the emerging oscillatory patterns. By increasing the inhibitory synaptic delay, we observe a transition from regular to mixed oscillatory patterns at a critical value. We also examine how the unreliability of inhibitory synapses influences the emergence of synchronization and the oscillatory patterns. We find that low levels of reliability tend to destroy synchronization and, moreover, that interneuronal networks with long inhibitory synaptic delays require a minimal level of reliability for the mixed oscillatory pattern to be maintained.
TL;DR: It is demonstrated that adaptive punishment promotes public cooperation through the invigoration of spatial reciprocity, the prevention of the emergence of cyclic dominance, or the provision of competitive advantages to those that sanction antisocial behavior.
Abstract: Cooperation is crucial for the remarkable evolutionary success of the human species. Not surprisingly, some individuals are willing to bare additional costs in order to punish defectors. Current models assume that, once set, the fine and cost of punishment do not change over time. Here we show that relaxing this assumption by allowing players to adapt their sanctioning efforts in dependence on the success of cooperation can explain both, the spontaneous emergence of punishment, as well as its ability to deter defectors and those unwilling to punish them with globally negligible investments. By means of phase diagrams and the analysis of emerging spatial patterns, we demonstrate that adaptive punishment promotes public cooperation either through the invigoration of spatial reciprocity, the prevention of the emergence of cyclic dominance, or through the provision of competitive advantages to those that sanction antisocial behavior. Presented results indicate that the process of self-organization significantly elevates the effectiveness of punishment, and they reveal new mechanisms by means of which this fascinating and widespread social behavior could have evolved.
TL;DR: A dynamically decelerated invasion process is revealed, by means of which interfaces separating different domains remain smooth and defectors therefore become unable to efficiently invade cooperators and establishes decentralized decision making as very beneficial for resolving social dilemmas.
Abstract: Whether or not to change strategy depends not only on the personal success of each individual, but also on the success of others. Using this as motivation, we study the evolution of cooperation in games that describe social dilemmas, where the propensity to adopt a different strategy depends both on individual fitness as well as on the strategies of neighbors. Regardless of whether the evolutionary process is governed by pairwise or group interactions, we show that plugging into the "wisdom of groups" strongly promotes cooperative behavior. The more the wider knowledge is taken into account the more the evolution of defectors is impaired. We explain this by revealing a dynamically decelerated invasion process, by means of which interfaces separating different domains remain smooth and defectors therefore become unable to efficiently invade cooperators. This in turn invigorates spatial reciprocity and establishes decentralized decision making as very beneficial for resolving social dilemmas.
TL;DR: Subcritical water extraction of phenolic compounds from pomegranate seed residues (PSR) was performed as mentioned in this paper, and the results showed that the optimum extraction time was 30min, solid to water ratio was 1:40, and the highest phenolic content (TPC) was obtained at 220°C.
TL;DR: In this article, the authors study the evolution of cooperation in games that describe social dilemmas, where the propensity to adopt a different strategy depends both on individual fitness as well as on the strategies of neighbors.
Abstract: Whether or not to change strategy depends not only on the personal success of each individual, but also on the success of others. Using this as motivation, we study the evolution of cooperation in games that describe social dilemmas, where the propensity to adopt a different strategy depends both on individual fitness as well as on the strategies of neighbors. Regardless of whether the evolutionary process is governed by pairwise or group interactions, we show that plugging into the “wisdom of groups” strongly promotes cooperative behavior. The more the wider knowledge is taken into account the more the evolution of defectors is impaired. We explain this by revealing a dynamically decelerated invasion process, by means of which interfaces separating different domains remain smooth and defectors therefore become unable to efficiently invade cooperators. This in turn invigorates spatial reciprocity and establishes decentralized decision making as very beneficial for resolving social dilemmas.
TL;DR: The presented results support the recently revealed importance of percolation for the successful evolution of public cooperation, while at the same time revealing surprisingly simple methods of self-organization towards socially desirable states.
Abstract: A collective-risk social dilemma implies that personal endowments will be lost if contributions to the common pool within a group are too small. Failure to reach the collective target thus has dire consequences for all group members, independently of their strategies. Wanting to move away from unfavorable locations is therefore anything but surprising. Inspired by these observations, we here propose and study a collective-risk social dilemma where players are allowed to move if the collective failure becomes too probable. More precisely, this so-called risk-driven migration is launched depending on the difference between the actual contributions and the declared target. Mobility therefore becomes an inherent property that is utilized in an entirely self-organizing manner. We show that under these assumptions cooperation is promoted much more effectively than under the action of manually determined migration rates. For the latter, we in fact identify parameter regions where the evolution of cooperation is greatly inhibited. Moreover, we find unexpected spatial patterns where cooperators that do not form compact clusters outperform those that do, and where defectors are able to utilize strikingly different ways of invasion. The presented results support the recently revealed importance of percolation for the successful evolution of public cooperation, while at the same time revealing surprisingly simple methods of self-organization towards socially desirable states.
TL;DR: It is shown that the remarkable promotion of cooperation is due primarily to the spontaneous emergence of quarantining of defectors, who become surrounded by conditional cooperators and are forced into isolated convex "bubbles" from which they are unable to exploit the public good.
Abstract: The fact that individuals will most likely behave differently in different situations begets the introduction of conditional strategies. Inspired by this, we study the evolution of cooperation in the spatial public goods game, where, besides unconditional cooperators and defectors, also different types of conditional cooperators compete for space. Conditional cooperators will contribute to the public good only if other players within the group are likely to cooperate as well but will withhold their contribution otherwise. Depending on the number of other cooperators that are required to elicit cooperation of a conditional cooperator, the latter can be classified in as many types as there are players within each group. We find that the most cautious cooperators, who require all other players within a group to be conditional cooperators, are the undisputed victors of the evolutionary process, even at very low synergy factors. We show that the remarkable promotion of cooperation is due primarily to the spontaneous emergence of quarantining of defectors, who become surrounded by conditional cooperators and are forced into isolated convex ``bubbles'' from which they are unable to exploit the public good. This phenomenon can be observed only in structured populations, thus adding to the relevance of pattern formation for the successful evolution of cooperation.
TL;DR: It is shown that pool-punishment in structured populations is sustainable, but only if second-order free-riders are sanctioned as well, and to a such degree that they cannot prevail.
Abstract: Although empirical and theoretical studies affirm that punishment can elevate collaborative efforts, its emergence and stability remain elusive. By peer-punishment the sanctioning is something an individual elects to do depending on the strategies in its neighborhood. The consequences of unsustainable efforts are therefore local. By pool-punishment, on the other hand, where resources for sanctioning are committed in advance and at large, the notion of sustainability has greater significance. In a population with free-riders, punishers must be strong in numbers to keep the "punishment pool" from emptying. Failure to do so renders the concept of institutionalized sanctioning futile. We show that pool-punishment in structured populations is sustainable, but only if second-order free-riders are sanctioned as well, and to a such degree that they cannot prevail. A discontinuous phase transition leads to an outbreak of sustainability when punishers subvert second-order free-riders in the competition against defectors.
TL;DR: In this paper, the authors aim to determine the level of job satisfaction of nursing professionals in Slovenian hospitals and factors influencing job satisfaction in nursing, using a survey conducted in Slovenia.
Abstract: Aim
To determine the level of job satisfaction of nursing professionals in Slovenian hospitals and factors influencing job satisfaction in nursing.
TL;DR: Compared to single- and double-bundle ACL reconstruction using an anatomic technique, individualized based on the patient’s native ACL size, Anatomic double-Bundle reconstruction is not superior to anatomic single-b Bundle reconstruction when an individualized ACL reconstruction technique is used.
Abstract: Background:Reconstruction of the anterior cruciate ligament (ACL) has become a commonly performed procedure. However, biomechanical studies have demonstrated that conventional single-bundle ACL reconstruction techniques are only successful in limiting anterior tibial translation but less effective for restoring rotatory laxity.Purpose:This study aimed to compare the results of single- and double-bundle ACL reconstruction using an anatomic technique, individualized based on the patient’s native ACL size. The authors hypothesized that there would be no difference between the results of anatomic single-bundle (ASB) and anatomic double-bundle (ADB) reconstruction when the surgical technique is individualized.Study Design:Cohort study; Level of evidence, 2.Methods:Depending on intraoperative measurements of the ACL insertion site size, patients were selected for either ASB (n = 32) or ADB (n = 69) ACL reconstruction. In all groups, hamstring tendons autograft was used with suspensory fixation on the femoral si...
TL;DR: It is found that spatial reciprocity peaks in the vicinity of the percolation threshold, when the emergence of a giant cooperative cluster is hindered neither by vacancy nor by invading defectors, thus discovering an intuitive yet universal law that links the population density with social prosperity.
Abstract: While worldwide census data provide statistical evidence that firmly link the population density with several indicators of social welfare, the precise mechanisms underlying these observations are largely unknown Here we study the impact of population density on the evolution of public cooperation in structured populations and find that the optimal density is uniquely related to the percolation threshold of the host graph irrespective of its topological details We explain our observations by showing that spatial reciprocity peaks in the vicinity of the percolation threshold, when the emergence of a giant cooperative cluster is hindered neither by vacancy nor by invading defectors, thus discovering an intuitive yet universal law that links the population density with social prosperity
TL;DR: Several new properties of a minimal counterexample to the conjecture are obtained and a lower bound for the domination number is proved for products of claw-free graphs with arbitrary graphs.
Abstract: Vizing's conjecture from 1968 asserts that the domination number of the Cartesian product of two graphs is at least as large as the product of their domination numbers. In this paper we survey the approaches to this central conjecture from domination theory and give some new results along the way. For instance, several new properties of a minimal counterexample to the conjecture are obtained and a lower bound for the domination number is proved for products of claw-free graphs with arbitrary graphs. Open problems, questions and related conjectures are discussed throughout the paper. © 2011 Wiley Periodicals, Inc. J Graph Theory 69: 46–76, 2012
TL;DR: In this article, the authors applied different combinations of normalization, weighting, and aggregation methods for the assessment of an industrial case study, with the aim of determining the best scheme for constructing composite indicators.
Abstract: The growing importance of sustainable development as a policy objective has initiated a debate about those suitable frameworks and tools useful for policy makers when making a sustainable decision. Composite indicators (CIs) aggregate multidimensional issues into one index, thus providing comprehensive information. However, it is frequently argued that CIs are too subjective, as their results undesirably depend on the normalization method, a specific weighting scheme, and the aggregation method of sub-indicators. This article applies different combinations of normalization, weighting, and aggregation methods for the assessment of an industrial case study, with the aim of determining the best scheme for constructing CIs. The applied methodology gradually aggregates sustainable development indicators into sustainability sub-indices and, finally, to a composite sustainability index. The normalization methods included in this analysis are: minimum–maximum, distance to a reference, and the percentages of annual differences over consecutive years. Equal weightings, the ‘benefit of the doubt’ approach, and budget allocation process were used for determining the weights of individual indicators and sustainability sub-indices. The linear, geometric, and non-compensatory multi-criteria approaches (NCMCs) were used as aggregation methods. The NCMC is modified to fit the two-level aggregation, then to sub-indices, and finally to a composite sustainable index. Also, a penalty criterion is introduced into the evaluation process with the aim of motivating the company to move towards sustainable development. The results are analyzed by variance-based sensitivity analysis. According to the results the recommended scheme for CIs’ construction is: distance to a reference–benefit of the doubt–linear aggregation.