Search results

A dual integral formulation for a cracked bar under torsion is derived, and a dual boundary element method is implemented. It is shown that as the thickness of the crack becomes thinner, the ill‐posedness for the linear algebraic matrix becomes more serious if the conventional BEM is used. Numerical experiments for solution instability due to ill‐posedness are shown. To deal with this difficulty, the hypersingular equation of the dual boundary integral formulation is employed to obtain an independent constraint equation for the boundary unknowns. For the sake of computational efficiency, the area integral for the torsion rigidity is transformed into two boundary integrals by using Green’s second identity and divergence theorem. Finally, the torsion rigidities for cracks with different lengths and orientations are solved by using the dual BEM, and the results compare well with the analytical solutions and FEM results.

The purpose of this paper is to present the method for solving the inverse Cauchy-type problem for the Laplace’s equation. Calculations were made for the rectangular domain with the target temperature on three boundaries and, additionally, on one of the boundaries, the heat flux distribution was selected. The purpose of consideration was to determine the distribution of temperature on a section of the boundary of the investigated domain (boundary Γ₁) and find proper method for the problem regularization.

The solution of the direct and the inverse (Cauchy-type) problems for the Laplace’s equation is presented in the paper. The form of the solution is noted as the linear combination of the Chebyshev polynomials. The collocation method in which collocation points had been determined based on the Chebyshev nodes was applied. To solve the Cauchy problem, the minimum of functional describing differences between the target and the calculated values of temperature and the heat flux on a section of the domain’s boundary was sought. Various types of the inverse problem regularization, based on Tikhonov and Tikhonov–Philips regularizations, were analysed. Regularization parameter α was chosen with the use of the Morozov discrepancy principle.

Calculations were performed for random disturbances to the heat flux density of up to 0.01, 0.02 and 0.05 of the target value. The quality of obtained results was next estimated by means of the norm. Effect of the disturbance to the heat flux density and the type of regularization on the sought temperature distribution on the boundary Γ₁ was investigated. Presented methods of regularization are considerably less sensitive to disturbances to measurement data than to Tikhonov regularization.

Discussed in this paper is an example of solution of the Cauchy problem for the Laplace’s equation in the rectangular domain that can be applied for determination of the temperature distribution on the boundary of the heated element where it is impossible to measure temperature or the measurement is subject to a great error, for instance on the inner wall of the boiler. Authors investigated numerical examples for functions with singularities outside the domain, for which values of gradients change significantly within the calculation domain what corresponds to significant changes in temperature on the wall of the boiler during the fuel combustion.

In this paper, a new method for solving the Cauchy problem for the Laplace’s equation is described. To solve this problem, the Chebyshev polynomials and nodes were used. Various types of regularization of this problem were considered.

This work compares the performance of the three boundary element techniques for solving Helmholtz problems: dual reciprocity, multiple reciprocity and direct interpolation. All techniques transform domain integrals into boundary integrals, despite using different principles to reach this purpose.

Comparisons here performed include the solution of eigenvalue and response by frequency scanning, analyzing many features that are not comprehensively discussed in the literature, as follows: the type of boundary conditions, suitable number of degrees of freedom, modal content, number of primitives in the multiple reciprocity method (MRM) and the requirement of internal interpolation points in techniques that use radial basis functions as dual reciprocity and direct interpolation.

Among the other aspects, this work can conclude that the solution of the eigenvalue and response problems confirmed the reasonable accuracy of the dual reciprocity boundary element method (DRBEM) only for the calculation of the first natural frequencies. Concerning the direct interpolation boundary element method (DIBEM), its interpolation characteristic allows more accessibility for solving more elaborate problems. Despite requiring a greater number of interpolating internal points, the DIBEM has presented higher-quality results for the eigenvalue and response problems. The MRM results were satisfactory in terms of accuracy just for the low range of frequencies; however, the neglected higher-order primitives impact the accuracy of the dynamic response as a whole.

There are safe alternatives for solving engineering stationary dynamic problems using the boundary element method (BEM), but there are no suitable comparisons between these different techniques. This paper presents the particularities and detailed comparisons approaching the accuracy of the three important BEM techniques, aiming at response and frequency evaluation, which are not found in the specialized literature.

This paper aims to develop an electrochemical dechlorination method for large objects in a short time, which were for a long time in the sea. Traditionally, in conservation, chlorides are extracted from marine iron artifacts using complete immersion of those objects in alkaline solutions with or without electrolysis. However, these techniques are time-consuming and very costly, especially when applied to large marine artifacts such as cannons and anchors.

An appropriate sponge was chosen based on resistance to NaOH and the rate of exacted chlorides. Application of electrochemical dechlorination in situ and removal of chloride were measured by the scanning electron microscope (SEM)-EDAX method on the corrosion products and by titration of the electrolysis solution. X-ray diffraction (XRD) method is used for identification of corrosion products before and after application of electrochemical chloride extraction.

The electrochemical chloride extraction (ECE) method is applied against the corrosion of reinforced concrete. From the authors’ research, it is obvious that ECE can successfully extract chlorides from dried large metallic objects exported from the sea. The method of ECE removes the majority of chlorides from the metal during conservation treatment so that the application of organic coating will allow the object to remain stable over a long period.

A new methodology was developed for dechlorination of metallic objects exported from the sea in a short time and thus the consumption of chemical reagents was cut down.

Circular economy denotes future sustainability that allows optimum utilization of resources. In the present era of technology, plenty of innovations are happening across the world, and digital manufacturing is one of such innovations. However, there are several barriers which are impeding adoption of digital manufacturing in circular economy environment. The study explores the barriers of digital manufacturing initiatives in a circular economy and develops a methodological model to prioritize the identified challenges for automotive parts manufacturing industry.

Seven categories of challenges namely process, human resources, financial, collaboration, technological, security and leadership challenges were identified from literature and further validated with subsequent discussions with experts from the industry. The study is conducted in two phases, where in the first phase, the Decision-Making Trial and Evaluation Laboratory (DEMATEL) technique is used to define the priority and importance of seven categories of challenges. In second phase, the barriers are ranked using a Fuzzy Performance Important Index (FPII), taking into account contextual factors associated with the challenges and linked barriers, to determine the extent to which they impede the adoption of digital manufacturing in the sample automotive parts manufacturing company.

The “risk of data security and information privacy in connection with use of external data and protecting customer data” appeared as the most significant barrier to digital manufacturing in circular economy. Furthermore, technological challenges emerged as the most significant category of challenges followed by financial challenges in adoption of digital manufacturing in circular economy.

Identification of the identified barriers and understanding the interrelationships will lead to easier adoption of digital manufacturing in circular economy.

Despite all the potential benefits of implementing Industry 4.0 technologies in manufacturing industries, the adoption thereof is still in nascent phase with significant challenges yet to be overcome to accelerate the pace of adoption. Hence, this study explores the barriers preventing companies from adopting and benefiting from digital manufacturing initiatives and further develops a methodological model.

China is a critical factor for constructing an all-round well-off society. Infrastructure construction, especially high-grade highways, in the western area is an essential component of the strategy for large-scale development of west China. It is crucial to evaluate investment projects for high-grade highways and select the best one. Testing investment projects and selecting the best one can be recognized as a multicriteria decision-making (MCDM) problem. In this process, decision-makers (DMs) usually face with uncertain information because of complicated decision environment or their limited knowledge.

A new Evaluation based on the Distance from Average Solution (EDAS) for PFS based on the DEMATEL is proposed: The authors offer a new score function and prove some properties for the score function. They put forward a novel Decision-making Trial and Evaluation Laboratory (DEMATEL) method for PFS to analyze the relations of criteria and get criteria weights. Considering the bounded rationality of DM, the authors propose a new EDAS method for PFS based on prospect theory. They apply their proposed approach to a western city's actual case in selecting a suitable project for building a high-grade highway.

By comparison, the authors can observe that our method has some traits: (1) considering bounded rationality of DM; (2) fewer computation; (3) having the ability to obtain the relation of criteria and finding the critical factor in the decision system.

In this paper, the authors propose a new EDAS method for PFS based on the DEMATEL technique. They transform PFS into crisp numbers by their proposed new score function for PFN to make the decision process more convenient. Then, the authors use the DEMATEL method to obtain the relationship between criteria and criteria weights. Furthermore, they propose a new EDAS method for PFS based on DEMATEL to reduce the computational complexity. Finally, they apply our method to a real case and compare our method with two traditional methods.

The purpose of this study is to identify the barriers to the adoption of blockchain technology in green supply chain management (GSCM) and further analyze the cause and effect relationship to prioritize the barriers for making strategic decisions.

The study examines 15 potential barriers related to the adoption of blockchain in GSCM which is identified from the literature review and finalized after subsequent discussions with industry professionals. Integrated Fuzzy-Decision-Making Trial and Evaluation Laboratory approach is used to analyze cause and effect relationships and prioritize the barriers. Fuzzy set theory is used to handle the uncertainty and vagueness associated with the personnel biases and data deficiency problems. Three small to medium enterprises’ (SMEs’) are considered for gathering data and further analyzing the crucial barriers that are impeding the adoption of blockchain technology in GSCM.

The findings reveal that “lack of management vision” and “cultural differences among supply chain partners” are the most influencing barriers, whereas; “collaboration challenges” and “hesitation and workforce obsolescence” are the most influential barriers in the adoption of blockchain in GSCM.

The study is developed based on 15 selected barriers which were further tested using data from three SMEs’ in the emerging economy of India. The adoption of blockchain technology in GSCM is at a nascent stage and more research studies are necessary to extend the knowledge base.

Managers need to eliminate the barriers and extend the blockchain technology application in GSCM. Managers need to develop the mission and vision of the company by doing proper alignment of blockchain technology with GSCM goals. Second, managers need to make strong collaborations and remove the hesitation and workforce obsolescence barrier by providing the right education and pieces of training.

Blockchain technology in GSCM is in a nascent stage. This study extends the knowledge base by identifying and further prioritizing the leading blockchain barriers that need to be overcome for effectively adopting blockchain in GSCM.

The validity and legitimacy of auditing profession depends on trust as one of the most important assets of auditing profession that trust itself is directly derived from capacity of this profession in responding to responsibilities. The present research has tried to identify 15 ethical values in auditing and analyzing causal relationships of ethical values in auditing from Islam’s perspective using fuzzy decision-making trial and evaluation laboratory (DEMATEL) approach. The purpose of this paper is analyzing causal relationships of ethical values in auditing from Islam’s perspective because ethical values improve auditing and keep the auditor’s independence.

Reviewing the literature and conducting a survey among 14 certified auditing experts, 15 ethical values in auditing were identified according to Islamic law using fuzzy DEMATEL techniques. Adopting this approach, the study was then to determine causal relationships and to identify influential values.

Based on the findings, the metrics “independence” with (D−R) = +1.045 was identified to be the cornerstone of the auditing profession. Independence is an essential component for users’ trust in the financial statements. If it is ignored, many other values will further make no sense. Truth-seeking as a value with (D + R) = +3.289 has the greatest interaction with other values, and this reveals that truth-seeking is one of the most significant auditing missions. Additionally, the value “trust” with (D−R) = −1.605 is mostly affected by other variables, suggesting that other values strongly influence this value, and it will be distorted if other values are ignored.

Auditing ethics is one of the most important and striking factors that maintains the credibility and dignity of the auditing profession. Today, the society’s expectations from auditing and accounting professions have increased. Increasing these expectations requires official accountants to provide their professional services in the form of ethical auditing. As this model has been designed using the ideas of the Muslim professional experts, the results may be different from those of non-Muslim professional experts.

Considering that identified values are of great importance in Islam religion, it seems that using Islamic culture and pragmatic tone by professionals, scholars and legislative bodies is necessary to create changes required in the current business culture and as the result to create fundamental changes in professional behaviors of auditing area. This study is the first to provide evidence on the improvement of auditing based on a review of auditing studies in Islam.

This research primarily aims to find and analyse the interaction among success factors for improving the performance of Indonesia’s dairy milk supply chain. Further, this research aims to formulate the right policies for improving the performance of the chain based on the success factor that belongs to cause groups.

The paper analyses 10 success factors for improving the performance of the Indonesian dairy supply chain with the decision-making trial and evaluation laboratory (DEMATEL) method and analyses the Delphi method to formulate the right policies for improving performance.

There are four important influencing factors that directly impact the overall system, i.e. the number of dairy cattle import, national milk demand, the total number of dairy farmers and the number of dairy cattle ownership or herd size. Several alternative policies have been designed by several experts according to the influencing factors, i.e. the government assists in the procurement of imported cattle, provides financial assistance to farmers in the form of low-interest financing, improves the partnership system between farmers and dairy cooperatives, provides a reward system for the farmers and increases the level of formality of contract between the farmers and cooperatives.

Interrelationships of each success factor and the most important influencing success factors could not be generally determined because it depends on the point of view of the experts. Future research can apply the success factors proposed by this research to the different dairy milk supply chain. Then, this research used only nine experts for formulating alternative policies. Future research may repeat this method using multiple experts to justify the validity of the research. Moreover, this research only explored 21 success factors of the increase in the performance of the Indonesian dairy supply chain. Future research should consider not only the supply side and number of dairy cattle but also several success factors from the causal relationship diagram in the broader dairy milk supply chain.

This research provides essential insights for policymakers, as they have to understand and evaluate the success factors before formulating several alternative policies.

The research has revealed that the right alternative policies can be designed, as the causal factor has been known.

This research contributes to applying a combination of causal relationship diagram of System Dynamic and DEMATEL method as a qualitative and quantitative method in one integrated way through performance dairy supply chain analysis. As a result, this research draws a policy for the dairy supply chain referring to the success factor as a cause for the low performance of the Indonesian dairy supply chain.

Supplier selection for capital procurement is a major strategic decision for any automobile company. The decision determines the success of the company and must be taken systematically with the utmost transparency. The purpose of this paper is to construct capital procurement decision-making model to optimize supplier selection in the Indian automobile industry.

To achieve the stated objective, a combined approach of fuzzy theory and AHP-DEMATEL is applied. Evaluation parameters are identified through an extensive literature review and criteria validation has been introduced through a Fuzzy Delphi method by using fuzzy linguistic scales to handle the vagueness of information. AHP is employed to find the priority weight of criteria, although an inter-relationship map among criteria is not possible through AHP alone since it considers all criteria as independent. To overcome this, DEMATEL is used to establish cause-effect relationships among criteria.

The results show that the total cost of ownership (TOC) is the first weighted criterion in supplier selection for capital procurement, followed by manufacturing flexibility and maintainability, then conformity with requirement. The cause-effect model shows that supplier profile, TOC, service support and conformity with requirement are in the cause group and are considered to be the most critical factors in selecting the supplier.

The study’s outcome can help the automobile industry to optimize their selection process in selecting their suppliers for capital procurement; the proposed model can provide guidelines and direction in this regard.