Environmental performance evaluation of suppliers: A hybrid fuzzy multi-criteria decision approach

Increasing environmental problems enforce companies to be more environmental responsible. A company’s environmental performance is not only related to the company’s inner environmental efforts, but also it is affected by the suppliers’ environmental performance and image. As a stakeholder of the company, a supplier with bad environmental image affects badly the company’s environmental image. Also, raw materials and semi-finished products supplied from out of the company recourses- suppliers- affects the products environmental features such as life cycle, re-usability, re-manufacturability, hazardous substances, etc. Considering these direct and indirect effects, managers should also consider environmental performances of their suppliers in their supplier evaluation process. In this paper, a methodology for the evaluation of suppliers’ environmental performances is proposed. In this methodology, a hybrid Fuzzy-Analytic Network Process and Fuzzy-Preference Ranking Organization METHod for Enrichment Evaluations approach is utilized. Additionally, a numerical example is given to foster the better understanding of the methodology and the obtained results are analyzed with sensitivity analyses.     

A GIS-based multi-criteria decision-making approach for establishing a regional-scale groundwater monitoring

A weighted multi-criteria decision-making framework was designed to identify and prioritize areas for monitoring aquifer hydraulic heads within the Victoria County Groundwater Conservation District. The criteria address salient hydrogeological aspects including groundwater variability, recharge, surface water–groundwater interactions, and groundwater fluxes across district boundaries. Texas water statutes require groundwater conservation districts to quantify these factors and utilize them to manage aquifers. A stakeholder survey instrument was used to prioritize these criteria. A monitoring priority index (MPI), whose value theoretically ranges between 0 and 1 was computed as a weighted average of six mutually exclusive criteria. The MPI value was seen to range between 0.2 and 0.6 within the study area. Lower values of MPI indicate areas where the current level of monitoring is adequate and areas with a higher MPI point to locations where additional monitoring is necessary. In particular, monitoring along district boundaries, particularly along the western and southern sections, is recommended. The developed methodology was seen to provide a transparent and simple-to-use approach to identify and prioritize areas within the district for the purposes of groundwater monitoring. The proposed framework demonstrates the utility of GIS in facilitating a scientifically credible and stakeholder-driven approach for establishing groundwater monitoring networks and can be adapted in other similar applications.     

A multi-criteria decision-making approach for quantification of accessibility to market facilities in rural areas: an application in Bangladesh

GeoJournal - The available approaches for measuring accessibility are rigid and complex in nature, and mostly impractical for decision-makers as they require a large number of data, logistics...     

An integrated data-mining and multi-criteria decision-making approach for hazard-based object ranking with a focus on landslides and floods

This study is aimed at conducting a hazard-based sustainability gap analysis considering spatial threats driven by floods and landslides, that is, a multi-hazard-based prioritization of the most important cities in Gorganrood Basin, Iran. Two data-mining models were used to assess the spatial probability of flood inundation and landslide occurrence, namely, support vector machine with the radial basis function kernel (SVM-RBF) and maximum entropy (ME). As inputs, a total of 124 flooded locations and 346 landslides with ten flood/landslide predisposing factors were mapped using geoinformatics and organizational data. The random selection method was used to split the flood and landslide inventories into two sets of train and test data. Tolerance index was used to test the multicollinearity among predictors. Validation of the models was carried out using the area under the receiver operating characteristic (ROC) curve (AUC). Finally, TOPSIS was used, as a multi-criteria decision-making model, to make an internal sustainability gap analysis to prioritize the threatened and safe cities. For flood inundation, the AUC values obtained from the test set revealed that the SVM-RBF outperformed ME in terms of predictive power and generalization capacity with the respective areas of 0.831 and 0.796 under the curve. For landslide susceptibility assessment, SVM-RBF again excelled ME in predictive power with the respective values of 0.887 and 0.84. Therefore, the susceptibility maps derived from SVM-RBF, as the premier model, were used for the next stage. Extracting the flood and landslide spatial probability values to 14 city points, the TOPSIS-Solver software made a prioritization using the similarity function to the ideal solution. Accordingly, Aliabad, Minoodasht, and Azadshahr cities, with having the smallest similarity coefficients, were found to be the top three spatially threatened cities in Gorganrood Basin, while Aq Qala, Gomishan, and Gonbad-e Kavus cities were placed at the bottom as the safest cities. This study can be a pivotal point in regional risk-based planning, implementation of further pragmatic measures, and allocation of resources for improving sustainable development most wisely.     

A method for evaluating radioactivity of rocks used in the building industry

This work proposes a method by which radium salt concentrations in rocks are determined. It also relates to radon amounts and emissions produced by these salts released into the environment, and, consequently, the affects on man by inhalation. Much of this can be ascribed to materials used in the building industry. On the basis of experimental results, the risk of this is expressed in the light of rules provided about radio-protection.     

A hypo-plastic approach for evaluating railway ballast degradation

Repetitive or cyclic rail loading deteriorates the engineering properties of the railway ballast by particle crushing and rearrangement. Most of the classical elasto-plastic models are unable to predict such ballast degradation despite successfully predicting the overall load–deformation behavior during cyclic densification. In this context, the present study delivers a novel hypo-plastic modeling approach coupled with breakage mechanics theory to bridge the gap of the conventional models. The hypo-plastic approach enables to predict the nonlinear load–deformation response of ballast-type granular materials for both monotonic and cyclic loading conditions, while circumventing the requirement of notional yield condition to predict the inelastic behavior. Breakage mechanics theory, on the other hand, establishes the links between particle comminution and the macroscopic deformation. The novelty of the proposed approach is threefold. Firstly, unlike the conventional hypo-plastic approaches, the development of the proposed model is within the continuum thermodynamics framework. Secondly, the model requires less number of physically identifiable parameters as compared to that of earlier models employed for assessing the particle breakage under cyclic loading. Third and finally, the numerical implementation of the model as a user-defined material is simple for solving boundary value problems. Under the compressive deformation regime, the model prediction of the ballast degradation along with the cyclic densification response agrees reasonably well with the experimental results found in the literature.     

A LabVIEW-based fire monitoring software using multi-criteria AHP approach for detecting geolocation of wildfire

Natural Hazards - High Conservation Value Forests or botanical parks are critical forested areas that need to be appropriately managed and protected against fire, as they contain large...     

A reliability based approach for evaluating the slope stability of embankment dams

Embankment dams are important and costly civil engineering structures that provide an essential infrastructure for the management of water. One of the critical aspects of dam design is the analysis of stability and safety of the earth structure under various operating and environmental conditions. Traditionally, a deterministic approach is used for such analysis. However, the determination of variables such as soil strength parameters, pore pressure and other pertinent properties involves uncertainties, which cannot be handled in the traditional deterministic methods. It is, therefore, highly desirable to develop a reliability based analytical/numerical methodology for stability analysis of dams taking into account these uncertainties. Reliability and probability theories are developed in this paper for assessing the reliability index and the corresponding probability of failure of multi-layered embankment dams and slopes. Two definitions were used to calculate the reliability index (i.e. the normal distribution and the log–normal distribution). The computer program was developed and validated by the Congress Street open cut failure case. The developed approach was used to study the stability of the King Talal embankment dam. The results are discussed and conclusions drawn.     

A fast numerical method for evaluating the performance of float-sink coal-cleaning equipment

A method is presented which seeks to overcome a number of disadvantages that are inherent in the conventional practice of plotting the Tromp curve and analysing it for its various measures, e.g., specific gravity of separation, probable error and error area. A sufficient condition is established for extracting the appropriate criteria of the sharpness of classification, which are independent of coal-feed distribution in specific gravity. Partition area, a modified areal measure, similar to the conventional error area, of the equipment's deviation from ideal classification behavior is derived from the theoretical partition function. A purely numerical procedure is developed for locating the specific gravity of separation and the partition area. Unlike the Tromp-curve-based conventional procedure, the proposed histogram-based method is fast, more convenient and objective for analysing the coal-cleaning plant data.     

GIS-based landslide susceptibility evaluation using fuzzy-AHP multi-criteria decision-making techniques in the Abha Watershed,Saudi Arabia

Landslides are natural geological disasters causing massive destructions and loss of lives, as well as severe damage to natural resources, so it is essential to delineate the area that probably will be affected by landslides. Landslide susceptibility mapping (LSM) is making increasing implications for GIS-based spatial analysis in combination with multi-criteria evaluation (MCE) methods. It is considered to be an effective tool to understand natural disasters related to mass movements and carry out an appropriate risk assessment. This study is based on an integrated approach of GIS and statistical modelling including fuzzy analytical hierarchy process (FAHP), weighted linear combination and MCE models. In the modelling process, eleven causative factors include slope aspect, slope, rainfall, geology, geomorphology, distance from lineament, distance from drainage networks, distance from the road, land use/land cover, soil erodibility and vegetation proportion were identified for landslide susceptibility mapping. These factors were identified based on the (1) literature review, (2) the expert knowledge, (3) field observation, (4) geophysical investigation, and (5) multivariate techniques. Initially, analytical hierarchy process linked with the fuzzy set theory is used in pairwise comparisons of LSM criteria for ranking purposes. Thereafter, fuzzy membership functions were carried out to determine the criteria weights used in the development of a landslide susceptibility map. These selected thematic maps were integrated using a weighted linear combination method to create the final landslide susceptibility map. Finally, a validation of the results was carried out using a sensitivity analysis based on receiver operator curves and an overlay method using the landslide inventory map. The study results show that the weighted overlay analysis method using the FAHP and eigenvector method is a reliable technique to map landslide susceptibility areas. The landslide susceptibility areas were classified into five categories, viz. very low susceptibility, low susceptibility, moderate susceptibility, high susceptibility, and very high susceptibility. The very high and high susceptibility zones account for 15.11% area coverage. The results are useful to get an impression of the sustainability of the watershed in terms of landsliding and therefore may help decision makers in future planning and mitigation of landslide impacts.     

A geo-ontology-based approach to decision-making in emergency management of meteorological disasters

Ontology as a kind of method for knowledge representation is able to provide semantic integration for decision support in emergency management activities of meteorological disasters. We examine a meteorological disaster system as composed of four components: disastrous meteorological events, hazard-inducing environments, hazard-bearing bodies, and emergency management. The geospatial characteristics of these components can be represented with geographical ontology (geo-ontology). In this paper, we propose an ontology representation of domain knowledge of a meteorological disaster system descending from an adapted geospatial foundation ontology, designed to formally conceptualize the domain terms and establish relationships between those concepts. The class hierarchy and relationships of the proposed ontology are implemented finally at top level, domain level/task level, and application level. The potential application of the ontology is illustrated with a case study of prediction of secondary disasters and evacuation decision of a typhoon event. The multi-level ontology model can provide semantic support for before-, during-, after-event emergency management activities such as risk assessment, resource preparedness, and emergency response where the formed concepts and their relationships can be incorporated into reasoning sentences of these decision processes. Furthermore, the ontology model is realized with a universally used intermediate language OWL, which enables it to be used in popular environments. This work will underlie the semantic integration among human beings, between heterogeneous systems and between human beings and systems, enable spatial semantic reasoning, and will be useful in guiding advanced decision support in emergency management of meteorological disasters.     

A multiphase approach for evaluating the horizontal and rocking impedances of pile group foundations

This paper advocates the use of a multiphase model, already developed for static or quasi‐static geotechnical engineering problems, for simulating the behaviour of piled raft foundations subject to horizontal as well as rocking dynamic solicitations. It is shown that such a model, implemented in a FEM code, yields appropriate predictions for the foundation impedance characteristics, provided that shear and bending effects in the piles are taken into account, thus corroborating the findings of the asymptotic homogenization theory. Besides, it is notably pointed out that such a multiphase‐based computational tool makes it possible to assess the dynamic behaviour of pile groups in a much quicker way than when using direct numerical simulations, which may face oversized problems when large pile groups are concerned. Copyright © 2016 John Wiley & Sons, Ltd.     

The optimal rotation of a flammable forest stand when both carbon sequestration and timber are valued: a multi-criteria approach

This paper proposes a multi-criteria approach that accounts for the risk of fire when determining the optimal rotation of a forest stand that is being managed for both timber production and carbon sequestration purposes. The multi-criteria framework uses in a combined way, multi-objective optimization and compromise programming methods. The proposed approach is computationally simple and allows for the quantification of conflicts between the criteria considered through the elicitation of the corresponding Pareto frontiers. Once the best portion or compromise sets of the Pareto frontiers are determined, then some indications of the increase in social welfare due to a potential reduction in the risk of fire are obtained. We illustrate the use of our methodology by applying it to an example that has previously been investigated in the forestry literature. Finally, some potential policy implications derived from the results obtained are highlighted.     

A statistical approach to evaluating distance metrics and analog assignments for pollen records

The modern analog technique typically uses a distance metric to determine the dissimilarity between fossil and modern biological assemblages. Despite this quantitative approach, interpretation of distance metrics is usually qualitative and rules for selection of analogs tend to be ad hoc. We present a statistical tool, the receiver operating characteristic (ROC) curve, which provides a framework for identifying analogs from distance metrics. If modern assemblages are placed into groups (e.g., biomes), this method can (1) evaluate the ability of different distance metrics to distinguish among groups, (2) objectively identify thresholds of the distance metric for determining analogs, and (3) compute a likelihood ratio and a Bayesian probability that a modern group is an analog for an unknown (fossil) assemblage. Applied to a set of 1689 modern pollen assemblages from eastern North America classified into eight biomes, ROC analysis confirmed that the squared-chord distance (SCD) outperforms most other distance metrics. The optimal threshold increased when more dissimilar biomes were compared. The probability of an analog vs no-analog result (a likelihood ratio) increased sharply when SCD decreased below the optimal threshold, indicating a nonlinear relationship between SCD and the probability of analog. Probabilities of analog computed for a postglacial pollen record at Tannersville Bog (Pennsylvania, USA) identified transitions between biomes and periods of no analog.     

A system reliability approach for evaluating stability of rock wedges with correlated failure modes

This paper proposes a system reliability approach for evaluating the stabilities of rock wedges considering multiple correlated failure modes. A probabilistic fault tree is employed to model the system aspects of the problem. The system reliability analysis is performed using an N-dimensional equivalent method taking into account correlations between different failure modes. Reliability sensitivity analyses at three different levels, namely, single limit state function level, single failure mode level, and system reliability level, were carried out to study the effect of changes in variables on the stability of the wedge. An example case was analysed to illustrate the proposed approach. The stability of the wedge can be evaluated efficiently using the proposed system reliability approach in a more systematic and quantitative way. The probabilities of failure of the wedge from the N-dimensional equivalent method are fairly consistent with those from the Monte Carlo simulation method. The results demonstrate that the probability of failure will be overestimated if the correlations between different failure modes of the wedge are not taken into account. They also demonstrate that the relative importance of different failure modes to the system reliability of the wedge can differ considerably and be treated systematically and quantitatively by the proposed approach. The sensitivity results are highly dependent on the selected sensitivity analysis level.     

Collaboration in industry: Empirical findings among small electronics manufacturing firms in the Greater Toronto Area

According to many researchers, the use of inter-firm collaborative practices as a new industrial production strategy is increasing as a response to industrial restructuring and changing environmental conditions. The adoption of these practices is thought to be particularly critical for small firms, and consequently governments in most industrialized countries have designed specific policies aimed at encouraging inter-firm relationships. The few empirical studies have focused on the experiences of model industrial districts to support claims about the ubiquity of collaborative relations. The present study of a more typical urban area examines three interrelated issues: the incidence of inter-firm relations, the motivations and forms of collaboration, and the influence of public policies on inter-firm relationships. Information was collected from 191 small electronics firms in the Greater Toronto Area (GTA). The results suggest that inter-firm collaboration is moderately common but not the norm. The incidence of collaborative activities is likely to increase with company size. While motives for inter-firm activities vary slightly with firm size, the nature and forms of agreements are largely similar among various sizes of firms. The paper notes that public policies and programs within the GTA have not had the desired impact of creating cooperative attitudes among small electronics firms. This revised version was published online in July 2006 with corrections to the Cover Date.     

A multi-criteria method for assessment of spatial data infrastructure effectiveness

There is a demand for evaluation of spatial data infrastructures (SDIs), to justify and monitor the relations between investments in SDI initiatives and the results obtained. It is also essential to pay particular attention to identifying user communities, and eliciting their assessment of effects deriving from an SDI. The paper introduces a concept of a multi-criteria method which allows to assess effectiveness of the SDI from the user perspective. The application of the proposed method in the Polish Spatial Data Infrastructure (PSDI) and its main access point to spatial data and services called ‘Geoportal 2’ as well as two groups of the national geoportal”s users (spatial planners and land surveyors) presents its potential. The total scores for the Geoportal 2 indicated the investment has potential and is quite effective, although some components of the PSDI (e.g. main access point, datasets, network services, software, hardware, procedures) may need improvements and additional analyses in the future. The contribution of this paper is the multi-criteria method which enables the analysis of outcomes, benefits (impacts) and business value of using SDI business project’s artifacts (outputs) considering the following dimensions: information and support provided, use process, user organizational performance, strategic alignment and business impact on user enterprise.     

A homogenization approach for evaluating the longitudinal shear stiffness of reinforced soils: column versus cross trench configuration

The macroscopic linear elastic behaviour of inclusion‐reinforced soils, regarded as periodic composite media, is investigated by means of the homogenization theory. Special attention is given here to the determination of their longitudinal shear stiffness properties, which strongly govern the reinforced ground response under lateral loading. Combining the use of analytical, variational and numerical methods, we thoroughly examined three particular engineering‐relevant configurations: single trench, column and cross trench reinforcements. Fairly accurate closed‐form expressions are thus obtained, giving the value of the reinforced soil longitudinal shear stiffness as a function of the individual components shear moduli and reinforcement volume fraction. It is shown in particular that adopting a cross trench reinforcement layout instead of the classical column configuration results in a much higher improvement of the longitudinal shear stiffness. The results are then applied to assessing the reduction of soil liquefaction risk, which can be attributed to the presence of the reinforcing inclusions. Again, they clearly demonstrate the excellent performance of the cross trench configuration as compared with the complete inefficiency of the column reinforcement technique. Copyright © 2013 John Wiley & Sons, Ltd.