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1 – 10 of over 33000Discusses the methods of sensitivity analysis in use generally andby the property appraisal profession. Proposes a simplified structuredand systematic technique of selecting…
Abstract
Discusses the methods of sensitivity analysis in use generally and by the property appraisal profession. Proposes a simplified structured and systematic technique of selecting critical or sensitive factors for sensitivity analysis in property development and investment appraisal. Concludes that sensitivity analysis has become an integral part of property appraisal.
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Yidu Zhang, Yongshou Liu and Qing Guo
This paper aims to develop a method for evaluating the failure probability and global sensitivity of multiple failure modes based on convex-probability hybrid uncertainty.
Abstract
Purpose
This paper aims to develop a method for evaluating the failure probability and global sensitivity of multiple failure modes based on convex-probability hybrid uncertainty.
Design/methodology/approach
The uncertainty information of the input variable is considered as convex-probability hybrid uncertainty. Moment-independent variable global sensitivity index based on the system failure probability is proposed to quantify the effect of the input variable on the system failure probability. Two-mode sensitivity indices are adopted to characterize the effect of each failure mode on the system failure probability. The method based on active learning Kriging (ALK) model with a truncated candidate regions (TCR) is adopted to evaluate the systems failure probability, as well as sensitivity index and this method is termed as ALK-TCR.
Findings
The results of five examples demonstrate the effectiveness of the sensitivity index and the efficiency of the ALK-TCR method in solving the problem of multiple failure modes based on the convex-probability hybrid uncertainty.
Originality/value
Convex-probability hybrid uncertainty is considered on system reliability analysis. Moment-independent variable sensitivity index based on the system failure probability is proposed. Mode sensitivity indices are extended to hybrid uncertain reliability model. An effective global sensitivity analysis approach is developed for the multiple failure modes based on convex-probability hybrid uncertainty.
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E. HINTON, N.V.R. RAO and J. SIENZ
This paper deals with structural shape and thickness optimization of axisymmetric shell structures loaded symmetrically. In the finite element stress analysis use is made of newly…
Abstract
This paper deals with structural shape and thickness optimization of axisymmetric shell structures loaded symmetrically. In the finite element stress analysis use is made of newly developed linear, quadratic, and cubic, variable thickness, C(0) elements based on axisymmetric Mindlin‐Reissner shell theory. An integrated approach is used to carry out the whole shape optimization process in a fully automatic manner. A robust, versatile and flexible mesh generator is incorporated with facilities for generating either uniform or graded meshes, with constant, linear, or cubic variation of thickness, pressure etc. The midsurface geometry and thickness variations of the axisymmetric shell structure are defined using cubic splines passing through certain key points. The design variables are chosen as the coordinates and/or the thickness at the key points. Variable linking procedures are also included. Sensitivity analysis is carried out using either a semi‐analytical method or a global finite difference method. The objective of the optimization is the weight minimization of the structure. Several examples are presented illustrating optimal shapes and thickness distributions for various shells. The changes in the bending, membrane and shear strain energies during the optimization process are also monitored.
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Javier Luis Mroginski, Pablo Alejandro Beneyto, Guillermo J Gutierrez and Ariel Di Rado
There are many problems in civil or mechanical engineering related to structural design. In such a case, the solution techniques which lead to deterministic results are no longer…
Abstract
Purpose
There are many problems in civil or mechanical engineering related to structural design. In such a case, the solution techniques which lead to deterministic results are no longer valid due to the heuristic nature of design problems. The purpose of this paper is to propose a computational tool based on genetic algorithms, applied to the optimal design of cross-sections (solid tubes) of 3D truss structures.
Design/methodology/approach
The main feature of this genetic algorithm approach is the introduction of a selective-smart method developed in order to improve the convergence rate of large optimization problems. This selective genetic algorithm is based on a preliminary sensitivity analysis performed over each variable, in order to reduce the search space of the evolutionary process. In order to account for the optimization of the total weight, the displacement (of a specific section) and the internal stresses distribution of the structure a multiobjective optimization function was proposed.
Findings
The numerical results presented in this paper show a significant improvement in the convergence rate as well as an important reduction in the relative error, compared to the exact solution.
Originality/value
The variables sensitivity analysis put forward in this approach introduces a significant improvement in the convergence rate of the genetic algorithm proposed in this paper.
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The purpose of this paper is to report a study in which the feasibility of conducting probabilistic finite element analysis (FEA) for crane hook design has been explored.
Abstract
Purpose
The purpose of this paper is to report a study in which the feasibility of conducting probabilistic finite element analysis (FEA) for crane hook design has been explored.
Design/methodology/approach
This paper presents the results of probabilistic analysis, where in the input random variables are varied and corresponding variations in the output parameters were observed. In this study, material properties and load have been considered as random input variables and the maximum stress, maximum deflection variations were considered as output random variables.
Findings
The probability of occurrence of output variation and the sensitivity of output variables on the input variables are the important results generated from this analysis. By performing this probabilistic analysis, the random selection of factor of safety could be avoided.
Research limitations/implications
The implementation study has been carried out for a single product.
Practical implications
The usage of the approach will indicate the importance of probabilistic analysis in product design and development process. This process will enable the organization to compete in the global market.
Originality/value
A case study has been reported to indicate the feasibility of performing probabilistic FEA for crane hook design. Hence, the contributions are original.
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Cemil Kuzey, Ali Uyar and Dursun Delen
The paper aims to identify and critically analyze the factors influencing cost system functionality (CSF) using several machine learning techniques including decision trees…
Abstract
Purpose
The paper aims to identify and critically analyze the factors influencing cost system functionality (CSF) using several machine learning techniques including decision trees, support vector machines and logistic regression.
Design/methodology/approach
The study used a self-administered survey method to collect the necessary data from companies conducting business in Turkey. Several prediction models are developed and tested; a series of sensitivity analyses is performed on the developed prediction models to assess the ranked importance of factors/variables.
Findings
Certain factors/variables influence CSF much more than others. The findings of the study suggest that utilization of management accounting practices require a functional cost system, which is supported by a comprehensive cost data management process (i.e. acquisition, storage and utilization).
Research limitations/implications
The underlying data were collected using a questionnaire survey; thus, it is subjective which reflects the perceptions of the respondents. Ideally, it is expected to reflect the objective of the practices of the firms. Second, the authors have measured CSF it on a “Yes” or “No” basis which does not allow survey respondents reply in between them; thus, it might have limited the choices of the respondents. Third, the Likert scales adopted in the measurement of the other constructs might be limiting the answers of the respondents.
Practical implications
Information technology plays a very important role for the success of CSF practices. That is, successful implementation of a functional cost system relies heavily on a fully integrated information infrastructure capable of constantly feeding CSF with accurate, relevant and timely data.
Originality/value
In addition to providing evidence regarding the factors underlying CSF based on a broad range of industries interesting finding, this study also illustrates the viability of machine learning methods as a research framework to critically analyze domain specific data.
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The aim of this paper is to undertake analysis and comparison of the closed‐loop and sensorless control systems sensitivity to the broken rotor for diagnostic purposes. For the…
Abstract
Purpose
The aim of this paper is to undertake analysis and comparison of the closed‐loop and sensorless control systems sensitivity to the broken rotor for diagnostic purposes. For the same vector control system induction motor drive analysis concerning operation with the asymmetric motor, broken rotor fault handling and operation were investigated. Reliability, range of stable operation, fault symptoms and application of diagnosis methods based on control system variables utilization was analyzed.
Design/methodology/approach
Induction motor drive vector control system synthesis was applied using the multiscalar variables of the machine model with nonlinear feedback linearization applied to use classical cascaded PI controllers for the speed‐torque and flux decoupled control. Speed observer was applied for the rotor flux and rotor speed estimation for the sensorless control system synthesis.
Findings
Relative sensitivity of the state and control system variables to broken rotor fault based on experimental results for the closed‐loop and sensorless control systems is presented and compared. Drawbacks of using the MCSA analysis for the rotor fault diagnosis in the closed‐loop and sensorless control systems are pointed. Advantages and drawbacks of the state space estimators filtering characteristics in the sensorless control system are described.
Practical implications
Asymmetric IM motor drive handling and diagnosis. Broken rotor range diagnosis inconsistency using the popular MCSA method should be considered in the closed‐loop and sensorless control system of the induction motor drive. Depending on the IM motor drive application and the operation requirements the results can be used for asymmetric machine proper handling, choosing proper control system structure and control system variables for rotor fault early diagnosis.
Originality/value
Sensitivity of the state and control system variables to broken rotor fault based on experimental results for the closed‐loop and sensorless control systems is presented, which implies motor handling procedures and fault diagnosis.
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This study aims to explore the relationship between risk governance characteristics (chief risk officer [CRO], chief financial officer [CFO] and senior directors [SENIOR]) and…
Abstract
Purpose
This study aims to explore the relationship between risk governance characteristics (chief risk officer [CRO], chief financial officer [CFO] and senior directors [SENIOR]) and regulatory adjustments (RAs) in Organization for Economic Cooperation and Development public commercial banks.
Design/methodology/approach
Using principal component analysis (PCA) and regression models, the research analyzes a representative data set of these banks.
Findings
A significant negative correlation between risk governance characteristics and RAs is found. Sensitivity analysis on the regulatory Tier 1 capital ratio and the total capital ratio indicates mixed outcomes, suggesting a complex relationship that warrants further exploration.
Research limitations/implications
The study’s limited sample size calls for further research to confirm findings and explore risk governance’s impact on banks’ capital structures.
Practical implications
Enhanced risk governance could reduce RAs, influencing banking policy.
Social implications
The study advocates for improved banking regulatory practices, potentially increasing sector stability and public trust.
Originality/value
This study contributes to understanding risk governance’s role in regulatory compliance, offering insights for policymaking in banking.
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William Rodney and Paul Gallimore
This paper identifies that the methods used to quantify the financial risk of appraisals of private sector projects for primary health care development have been inadequate. Data…
Abstract
This paper identifies that the methods used to quantify the financial risk of appraisals of private sector projects for primary health care development have been inadequate. Data was collected and analysed from private developers on 18 schemes, varying by scale and location. It is argued that this is important for those involved with facilities management as well as those directly involved with the financial risk appraisal of a PFI/PPP project. Financial risks are more likely to arise when certain build designs are used which make projects more susceptible to particular risks. The paper makes recommendations on the appraisal of future projects for value for money reflecting the risk transfer achieved and devising a common, systematic format to provide consistency and standardisation. It concludes, however, that systems should not be formulated which might act as disincentives to the private sector, or impose increased workloads on the public sector in assessing proposals.
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Riccardo Natoli and Segu Zuhair
– The purpose of this paper is to demonstrate the potential of the resource-infrastructure-environment (RIE) index as a supplementary tool to assist policy makers.
Abstract
Purpose
The purpose of this paper is to demonstrate the potential of the resource-infrastructure-environment (RIE) index as a supplementary tool to assist policy makers.
Design/methodology/approach
This study undertakes a sensitivity analysis (SA) to assess the responsiveness of the RIE index to potential policy actions on three countries: Australia (mid-industrialised nation), Mexico (emerging economy) and the USA (highly industrialised nation).
Findings
The results show that the RIE framework is capable of accommodating SA to guide the policymakers on the directional changes of the index to measurable changes to its component parts.
Research limitations/implications
Although the initial results seem promising, further refinement of the indicator is required before it can be practically implemented. For instance, the RIE framework has yet to incorporate dimensions to represent distribution and effects of substitution.
Originality/value
The paper undertakes a SA to assess the responsiveness of the RIE index which is an alternative measure of progress for nations that has the capability to capture more aspects important to progress.
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