Can B. Kalayci and Surendra M. Gupta
Disturbing increase in the use of virgin resources to produce new products has threatened the environment. Many countries have reacted to this situation through regulations which…
Abstract
Disturbing increase in the use of virgin resources to produce new products has threatened the environment. Many countries have reacted to this situation through regulations which aim to eliminate negative impact of products on the environment shaping the concept of environmentally conscious manufacturing and product recovery (ECMPRO). The first crucial and the most time-consuming step of product recovery is disassembly. The best productivity rate is achieved via a disassembly line in an automated disassembly process. In this chapter, we consider a sequence-dependent disassembly line balancing problem (SDDLBP) with multiple objectives that is concerned with the assignment of disassembly tasks to a set of ordered disassembly workstations while satisfying the disassembly precedence constraints and optimizing the effectiveness of several measures considering sequence-dependent time increments among disassembly tasks. Due to the high complexity of the SDDLBP, there is currently no known way to optimally solve even moderately sized instances of the problem. Therefore, an efficient methodology based on the simulated annealing (SA) is proposed to solve the SDDLBP. Case scenarios are considered and comparisons with ant colony optimization (ACO), particle swarm optimization (PSO), river formation dynamics (RFD), and tabu search (TS) approaches are provided to demonstrate the superior functionality of the proposed algorithm.
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Can B. Kalayci, Olcay Polat and Surendra M. Gupta
The purpose of this paper is to efficiently solve disassembly line balancing problem (DLBP) and the sequence-dependent disassembly line balancing problem (SDDLBP) which are both…
Abstract
Purpose
The purpose of this paper is to efficiently solve disassembly line balancing problem (DLBP) and the sequence-dependent disassembly line balancing problem (SDDLBP) which are both known to be NP-complete.
Design/methodology/approach
This manuscript utilizes a well-proven metaheuristics solution methodology, namely, variable neighborhood search (VNS), to address the problem.
Findings
DLBPs are analyzed using the numerical instances from the literature to show the efficiency of the proposed approach. The proposed algorithm showed superior performance compared to other techniques provided in the literature in terms of robustness to reach better solutions.
Practical implications
Since disassembly is the most critical step in end-of-life product treatment, every step toward improving disassembly line balancing brings us closer to cost savings and compelling practicality.
Originality/value
This paper is the first adaptation of VNS algorithm for solving DLBP and SDDLBP.
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Can B. Kalayci and Surendra M. Gupta
The purpose of this paper is to introduce sequence‐dependent disassembly line balancing problem (SDDLBP) to the literature and propose an efficient metaheuristic solution…
Abstract
Purpose
The purpose of this paper is to introduce sequence‐dependent disassembly line balancing problem (SDDLBP) to the literature and propose an efficient metaheuristic solution methodology to this NP‐complete problem.
Design/methodology/approach
This manuscript utilizes a well‐proven metaheuristics solution methodology, namely, ant colony optimization, to address the problem.
Findings
Since SDDLBP is NP‐complete, finding an optimal balance becomes computationally prohibitive due to exponential growth of the solution space with the increase in the number of parts. The proposed methodology is very fast, generates (near) optimal solutions, preserves precedence requirements and is easy to implement.
Practical implications
Since development of cost effective and profitable disassembly systems is an important issue in end‐of‐life product treatment, every step towards improving disassembly line balancing brings us closer to cost savings and compelling practicality.
Originality/value
This paper introduces a new problem (SDDLBP) and an efficient solution to the literature.
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Iman Mohammadi, Hamzeh Mohammadi Khoshouei and Arezoo Aghaei Chadegani
In this study, to maximize returns and minimize investment risk, an attempt was made to form an optimal portfolio under conditions where the capital market has a price bubble…
Abstract
Purpose
In this study, to maximize returns and minimize investment risk, an attempt was made to form an optimal portfolio under conditions where the capital market has a price bubble. According to the purpose, the research was of the applied type, in terms of data, quantitative and postevent, and in terms of the type of analysis, it was of the descriptive-correlation type. Sequence, skewness and kurtosis tests were used to identify the months with bubbles from 2015 to 2021 in the Tehran Stock Exchange. After identifying the bubble courses, artificial bee colony meta-heuristic and invasive weed algorithms were used to optimize the portfolio. The purpose of this paper is to address these issues.
Design/methodology/approach
The existence of bubbles in the market, especially in the capital market, can prevent the participation of investors in the capital market process and the correct allocation of financial resources for the economic development of the country. However, due to the goal of investors to achieve a portfolio of high returns with the least amount of risk, there is need to pay attention to these markets increases.
Findings
The results identify 14 periods of price bubbles during the study period. Additionally, stock portfolios with maximum returns and minimum risk were selected for portfolio optimization. According to the results of using meta-heuristic algorithms to optimize the portfolio, in relation to the obtained returns and risk, no significant difference was observed between the returns and risk of periods with price bubbles in each of the two meta-heuristic algorithms. This study can guide investors in identifying bubble courses and forming an optimal portfolio under these conditions.
Research limitations/implications
One of the limitations of this research is the non-generalizability of the findings to stock exchanges of other countries and other time periods due to the condition of the price bubble, as well as other companies in the stock market due to the restrictions considered for selecting the statistical sample.
Originality/value
This study intends to form an optimal stock portfolio in a situation where the capital market suffers from a price bubble. This study provides an effective and practical solution for investors in the field of stock portfolio optimization.
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Hasan Tutar, Salih Tutar, Batuhan Medetoglu and Muhammed Kalayci
Assessing the performance and stability of financial institutions is crucial for investors, regulators and stakeholders. The primary purpose of this study was to examine the…
Abstract
Purpose
Assessing the performance and stability of financial institutions is crucial for investors, regulators and stakeholders. The primary purpose of this study was to examine the economic resilience and sustainability performance of banks operating in Türkiye through their capital adequacy, asset quality, management quality, earnings, liquidity, and sensitivity to market risk (CAMELS) and environmental, social and governance (ESG) scores. The research examined whether there was a significant relationship between the CAMELS and ESG scores of the banks in the sample and how they affected each other.
Design/methodology/approach
This study analyzed the relationship between the CAMELS and ESG scores of five public and private banks operating in Türkiye. The study used statistical techniques such as correlation, regression and descriptive statistics to analyze the relationship between the CAMELS and the ESG score clusters. The data in the research cover the period 2008–2022 and were obtained from open sources disclosed to the public by the banks.
Findings
The study found a statistically significant relationship between the financial institutions’ CAMELS and ESG scores. Banks with higher CAMELS scores had a better ESG performance; however, this relationship was not linear. Regression analysis allowed for the identification of factors that had a significant impact on ESG scores within the CAMELS framework. No effect was detected on earnings (E), one of the CAMELS elements in the “economic, environmental, and governance elements” section of the banks' ESG scores. Management quality (M) positively affected only governance (G). Additionally, it was determined that the banks’ environmental performance (ENV) positively affected their CAMELS score.
Practical implications
The positive relationship between the CAMELS and ESG dimensions shows that financial sustainability is essential. The findings are expected to enrich the understanding of financial institutions’ resilience in the context of Türkiye, which constitutes the research sample. In addition, the inferences that can be made from this Turkish sample are essential for informing investment decisions, regulatory frameworks and broader stakeholder engagement in similar markets.
Social implications
Although a significant and positive relationship was established between ESG and CAMELS scores, a substantial and positive relationship only sometimes emerged when the sub-elements of the variables in question were examined. Investing in environmental initiatives helps companies build sustainable business models for the long term, paving the way for future profits and improved capital adequacy and liquidity. However, new regulations and practices related to environmental activities may introduce additional costs, necessitating changes to existing business processes.
Originality/value
This study provides important information regarding the interaction in financial institutions between financial stability assessed by CAMELS scores and sustainability performance measured by ESG scores. The findings show that institutions with robust economic fundamentals demonstrate better ESG performance. This indicates that there is a positive relationship between financial stability and responsible business practices. This information will help investors, regulators and stakeholders to make informed decisions about financial institutions, decisions that focus on sustainability. The results also suggest that it is necessary to use dynamic models and analytical tools to address the link between CAMELS and ESG.
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Zeliha Özlü-Erkilic, Dietmar Winkler, Christian Popow, Heidi Elisabeth Zesch and Türkan AKKAYA-KALAYCI
The migration background can influence the life satisfaction of migrants. The purpose of this paper is to examine the life satisfaction of migrants and particularly the…
Abstract
Purpose
The migration background can influence the life satisfaction of migrants. The purpose of this paper is to examine the life satisfaction of migrants and particularly the satisfaction regarding their health in comparison to natives.
Design/methodology/approach
The life satisfaction of 50 Turkish-speaking migrants living in Vienna was compared with the life satisfaction of 50 native Austrians by the questionnaire of life satisfaction by Fahrenberg et al. (2000).
Findings
Turkish-speaking migrants had lower values than natives in all scales of the questionnaire concerning life satisfaction. Turkish-speaking women reported the lowest satisfaction regarding their health state. In the migrant group the satisfaction regarding health decreased with increasing age.
Research limitations/implications
The Turkish version of the questionnaire was translated into Turkish by authors but not formally validated. Furthermore acculturation strategies as well as the mental and physical health state of the participant, which can crucially influence the life satisfaction of migrants, were not surveyed.
Practical implications
Migrants have lower life satisfaction possibly because of their physical and mental health problems. Therefore in countries with a high proportion of migrants the health-care system should be adapted for the needs of migrants, especially for the needs of women and older migrants in order to increase the utilization of the health-care services, primarily the use of the preventive health-care services.
Social implications
The results of the present study can be helpful to develop strategies for improving the life satisfaction of migrants, especially the satisfaction regarding their health.
Originality/value
To the authors’ knowledge, the present study is the first research project in Vienna conducted to estimate the impact of migration background on life satisfaction.
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The purpose of this paper is to present an interactive system to enable product design for disassembly and to offer robust and quick design solutions based on designers’ input.
Abstract
Purpose
The purpose of this paper is to present an interactive system to enable product design for disassembly and to offer robust and quick design solutions based on designers’ input.
Design/methodology/approach
The system utilizes an interactive questionnaire to communicate with the designer. The questionnaire is in the form of binary questions (Yes/No) and design questions that would enable the system to learn the objectives of the design. Solutions are based on a CAD supported design platform. The efficiency of each design is calculated using disassembly time as the metric of measurement using motion-time measurement (MTM). The designer would be able to make an informed decision with respect to component functionality, ease of disassembly and disassembly time. The paper presents a detailed framework and structure of this system.
Findings
The value of the system is corroborated by means of a case study of an actual product design. The system is structured to offer multiple solutions to a design problem so as to enable the designer to choose the option that best serves their needs.
Originality/value
This novel interactive system would accept customers’ design preferences as input and offer multiple solutions in order to solve the design problem. Process time is directly calculated using the MTM system of measurement by converting design features into time measurement units. Disassembly time can then be easily converted into disassembly cost by using standard conversion rates. The value to designers is obvious.