Application of the matrix approach in risk assessment Kovačević, Nenad; Stojiljković, Aleksandra; Kovač, Mitar
Operational Research in Engineering Sciences: Theory and Applications,
12/2019, Letnik:
2, Številka:
3
Journal Article
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The risk assessment process is based on risk management. Risk assessment is, in principle, an entirely empirical decision-making process, based on risk assessors’ knowledge and experience, necessary ...to identify (a) hazard(s) as the cause for risk by using specific and well-known and recognized methods so far. Currently, there are a large number of methods recognized for risk assessment, which are mostly formed by various organizations and associations of engineers, usually in insurance companies. The paper presents the most pragmatic matrix (qualitative) risk assessment methods, such as: a 3x3 matrix (OHSAS), a 4x4 matrix (AS/NZS 4360) and a 5x5 matrix (MIL-STD-882B). The paper is significant in that the matrix approach in risk assessment is the basis for the development of risk assessment methods, regardless of the method of the group which they belong to.
In this paper we aim to derive solutions for the SU(N) self-dual Yang–Mills (SDYM) equation with arbitrary N. A set of noncommutative relations are introduced to construct a matrix equation that can ...be reduced to the SDYM equation. It is shown that these relations can be generated from two different Sylvester equations, which correspond to the two Cauchy matrix schemes for the (matrix) Kadomtsev–Petviashvili hierarchy and the (matrix) Ablowitz–Kaup–Newell–Segur hierarchy, respectively. In each Cauchy matrix scheme we investigate the possible reductions that can lead to the SU(N) SDYM equation and also analyze the physical significance of some solutions, i.e. being Hermitian, positive-definite and of determinant being one.
•Solutions of the SU(N) SDYM equation with arbitrary N are constructed.•The SU(N) SDYM is formulated by the Cauchy matrix scheme of the KP hierarchy.•The SU(2N) SDYM is formulated by the Cauchy matrix scheme of the AKNS hierarchy.•Some solutions of the SU(2N) SDYM obtained in the two schemes are analyzed.
Two types of extended KdV equations generated by squared eigenfunction symmetries are derived with Cauchy matrix approach opening up different ideas that may be of considerable interest of ...understanding for the integrable system’s homology. The unified-form solution is discussed through choosing different matrices of determining equation set. Furthermore, under a safe range of parameters and the integrability conditions, it is possible to construct the soliton solution into the unified form, which can also verify that Cauchy matrix approach is an effective mathematical tool for investigating the integrable system.
•An updated version of an ecosystem service potential assessment matrix is presented.•The approach combines potentials for 38 ecosystem services in terrstrial, marine and coastal habitats.•Some ...applications of the matrix are demonstrated for Northern German land- and seascape types.•Uncertainties, potential applicability and future challenges are discussed.
In this article, a revised and enlarged version of a qualitative assessment matrix for the appraisal of ecosystem service potentials is introduced. The product is a simple tool for scoring terrestrial, coastal and marine ecosystem types with respect to their abilities to provide provisioning, regulating and cultural ecosystem services as well as indicators of ecosystem state by applying criteria of ecosystem integrity. The methodological steps of matrix development are described, and the emerging expert opinions are illustrated by characterizing different ecosystem types, analysing different ecosystem services and showing the outcomes of linked GIS-based mapping exercises. The applicability of the matrix is demonstrated by some case studies. The related uncertainties are characterized and discussed in context with limitations, arising challenges and conceptual problems. The tool is made available on the internet, and the authors are looking forward to critical checks and proposals for improvement.
Organizations worldwide are now embracing different standards while approaching environmental management systems (EMS) to be environmentally and economically sustainable. The ISO 14001 EMS has ...captured much attention by offering efficient environmental practices organization-wide and throughout the supply chain. Human factors (HFs) are crucial behind implementing ISO 14001 EMS since research articles about ISO 14001 strongly emphasize different HFs. This study proposes a framework that solely focuses on those HFs. Influential HFs are extracted through content analysis of related literature and categorized into 5 main HFs. Opinions from experts in the relevant field about interrelationships and inheritances of the HFs are collected and converted into quantitative data. Incorporating the graph theoretic and matrix approach (GTMA), the data delivered permanent values corresponding to the main HFs and their best and worst possible values. Among the main HFs, EMS Training has been found to have the most scopes for improvement, followed by Employee Empowerment and EMS Teamwork. This study demonstrates a framework about how to assess the role of HFs behind internalizing ISO 14001 EMS and enables organizations to go for competitive benchmarking and to define and adjust goals for environmental management.
Predicting the fate of ecologies is a daunting, albeit extremely important, task. As part of this task one needs to develop an understanding of the organization, hierarchies, and correlations among ...the species forming the ecology. Focusing on complex food networks we present a theoretical method that allows to achieve this understanding. Starting from the adjacency matrix the method derives specific matrices that encode the various inter-species relationships. The full potential of the method is achieved in a spatial setting where one obtains detailed predictions for the emerging space–time patterns. For a variety of cases these theoretical predictions are verified through numerical simulations.
•A method is presented that allows to understand correlations among species.•The method derives matrices that encode the various inter-species relationships.•The full potential of the method is achieved in a spatial setting.•For some cases these theoretical predictions are verified through simulations.
In recent years, circular economy has become a matter of great importance because of its ability to contribute toward economic, environmental, and social aspects of the sustainability. The circular ...economy approaches help in resource conservation by reducing, reusing, and recycling products/parts/components/materials. On the other hand, Industry 4.0 is coupled with emerging technologies, which support the firms in efficient resource utilization. These innovative technologies can transform the present manufacturing organizations by reducing resource extraction, CO2 emissions, environmental damage, and power consumption and improve it into a more sustainable manufacturing organization. Industry 4.0 along with circular economy concepts greatly improves the circularity performance. However, there is no framework found for measuring the circularity performance of the firm. Therefore, the current study aims to develop a framework for measuring performance in terms of circularity percentage. In this work, graph theory and matrix approach are employed for measuring the performance based on a sustainable balanced scorecard such as internal process, learning and growth, customer and financial with environmental and social perspectives. A case of an Indian barrel manufacturing organization is discussed for the illustration of proposed methodology. Based on "circularity index" of the organization and the maximum possible circularity index, the circularity was found to be 5.10%. It indicates that there is a huge potential for the improvement in the circularity of the organization. An in-depth sensitivity analysis and comparison are also performed to validate the findings. There are very few studies on measuring the circularity. The study developed the approach for measuring circularity, which may be utilized by industrialists and practitioners for improving the circularity.
This brief focuses on presenting a state-based matrix approach to the problem of fault detection for discrete event systems (DESs). Firstly, the given system is modeled as a finite state machine and ...converted into algebraic structure with the help of semi-tensor product of matrices. Assuming that the faults influence only the state transition and can't recover, there are two possible constructions for the system: a normative and a faulty one. Considering the evolutionary process for the two systems, labeled correlative matrices between current state and initial state are established, respectively, which have an advantage in computer storage compared with existent methods. And then, a theorem is proposed as a criterion of detectable faults, followed with a corresponding algorithm to verify whether the faults are detectable for a given system. Finally, the approach in this brief is tested effectively for the exhaust gas recirculation system.
Through first-principles real-time density-matrix (FPDM) dynamics simulations, we investigated spin relaxation due to electron–phonon and electron–impurity scatterings with spin–orbit coupling (SOC) ...in two-dimensional Dirac materials silicene and germanene at finite temperatures. We discussed the applicability of conventional descriptions of spin relaxation mechanisms by Elliott-Yafet (EY) and D’yakonov-Perel’ (DP) compared to the FPDM method, which is determined by a complex interplay of intrinsic SOC, external fields, and scattering strength. For example, the electric field dependence of the spin lifetime by FPDM is close to the DP mechanism for silicene at room temperature but similar to the EY mechanism for germanene. Because of its stronger SOC strength and buckled structure in contrast to graphene, germanene has a giant spin lifetime anisotropy and spin-valley locking effect under nonzero E z and low temperatures. More importantly, germanene has a long spin lifetime (∼100 ns at 50 K) and an ultrahigh carrier mobility, making it advantageous for spin-valleytronic applications.
Pakistan Railway (PR) is vital to the country's transportation infrastructure, facilitating passenger and freight transportation. However, the growing number of accidents associated with PR has ...raised concerns about its overall safety. In addition, there have been limited research efforts to investigate PR accidents and their underlying causes The present study conducts a comprehensive risk assessment and safety management of PR using a semi-quantitative risk matrix approach. The study combines historical accident data and expert evaluations to assess the likelihood and consequences of different railway accident types and potential contributing factors. The descriptive statistics analysis has revealed varying degrees of severity for different types of railway accidents in Pakistan. For instance, accidents like passenger and goods train derailments and collisions at unmanned level crossings were identified as extreme and intolerable, whereas train fire accidents were categorized as high and undesirable. Moreover, accidents attributed to human error are classified as extreme and intolerable, while those caused by negligence of road users and track defects are classified as high and undesirable. The study utilized the risk matrix approach and identified critical risk areas that can help the decision-makers prioritize effective risk mitigation strategies. In light of the present study's findings, policy implications, such as investment in infrastructure to mitigate risks associated with aging or deteriorating tracks, bridges, and tunnels, and human resource development for railway personnel to improve their skills, decision-making abilities, and awareness of safety protocols, are recommended.
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