Mahdi Rajabzadeh, Seyed Mohammad Taghi Bathaee and M. A. Golkar
This paper investigates the DC-Link voltage regulation of fuel cell electric vehicle (FCEV) with hybrid power source (HPS). The HPS consists of fuel cell (FC) as the main source…
Abstract
Purpose
This paper investigates the DC-Link voltage regulation of fuel cell electric vehicle (FCEV) with hybrid power source (HPS). The HPS consists of fuel cell (FC) as the main source and ultracapacitor (UC) as the auxiliary source in order to compensate for the slow dynamics of FC in transient conditions. The system is a multiconverter structure which is comprised of a boost DC/DC converter and a buck-boost converter connecting FC and UC to DC-link respectively.
Design/methodology/approach
The FCEV is modeled dynamically, considering the nonlinear behavior of HPS and multiconverter system. This paper presents an advanced control approach based on the control Lyapunov function (CLF) to regulate the DC-link voltage and impeccable tracking of UC current to its references. The stability analysis of closed loop system is also insured.
Findings
The performance of proposed controller is illustrated via Simulink® using numerical simulations under European Extra Urban Driving Cycle (EUDC). The simulation results show that the presented method is both satisfactory and consistent with expectation.
Originality/value
The proposed control method is state of the art in FCEV and improves the energy management system.
Ali Haji Gholam Saryazdi and Mohammad Ghavidel
The purpose of this paper is to investigate the dynamics of waste production in the product structure of a wire and cable manufacturing company that deals with a high-volume waste…
Abstract
Purpose
The purpose of this paper is to investigate the dynamics of waste production in the product structure of a wire and cable manufacturing company that deals with a high-volume waste and proposes strategies that reduce product costs.
Design/methodology/approach
The methodology for this research is descriptive and expressive modeling in a way that theories of research have been extracted from literature and field studies have been done based on the company specialists’ views. The system dynamics has been used to analyze and model waste in a wire and cable firm.
Findings
Applying SD approach in the paper not only helps to identify the structure of producing the waste, which is complicated and dynamic, but also proposes ways to reduce them and illustrate the applied results. The second outcome shows that in the waste management there should be a digression in a managerial view to the systematic thought. In the other word as in the system dynamic approach, the expansion of the model boundary is one of the objectives to find appropriate solution. The behavior model showed that in the waste management the most effective way to reduce the waste is to buy qualified raw material which is out of the firm.
Originality/value
This paper not only shows that the system dynamic approach is appropriate for the waste management problems which are complicated and dynamic but also proved that in the waste management system the solutions are not always near or within the firm. They should be identified by a systematic approach.
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Mahdi Salehi, Samira Ahmadzadeh and Fahimeh Irvani Qale Sorkh
The present study aims to assess the potential effects of intellectual capital (IC) and disclosure of firms' affiliate transactions on contractual costs (CC).
Abstract
Purpose
The present study aims to assess the potential effects of intellectual capital (IC) and disclosure of firms' affiliate transactions on contractual costs (CC).
Design/methodology/approach
The statistical population of the study includes 768 firm-year observations listed on the Tehran Stock Exchange during 2012–2017. According to Pulic's model, the authors divide IC into three components, such as human capital (HC), relational capital and structural capital (SC). CC is also measured by utilising two variables of board cash compensation and unexpected reward of managers.
Findings
The results show that there is a negative and significant relationship between HC and CC. In contrast, the authors find that relational capital and SC have a positive impact on CC. The authors’ further analyses also demonstrate that disclosure of transactions with affiliates has a negative effect on unexpected rewards of managers.
Originality/value
Since there is no conducted study, which discusses the relationship between IC and contractual cost, this paper might be considered the primary studies conducted in this line of literature, specifically in emerging markets. Moreover, to the best of the authors' knowledge, this is the first study investigating the potential impact of disclosure of selling and purchasing transactions, separately, on the director's unexpected reward.
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Peivand Ghasemzadeh, Seyed Mahdi Rezayat Sorkhabadi, Abbas Kebriaeezadeh, Jamal Aldin Nazari, Mandana Farzaneh and Gholamhossein Mehralian
Innovative organizations are increasingly facing challenges in a dynamic market to address corporate social responsibility (CSR) issues; however, research on how organizational…
Abstract
Purpose
Innovative organizations are increasingly facing challenges in a dynamic market to address corporate social responsibility (CSR) issues; however, research on how organizational learning (OL) contributes to organizations’ social responsibility and innovation remains sparse. This study aims to bridge the gap in previous research and examines how OL and dynamic capabilities (DCs) act as drivers of CSR performance (CSRP) and innovation performance.
Design/methodology/approach
This study is survey-based and uses time-lagged, multisource data from 151 pharmaceutical industry-related companies in Iran. Structural equation modeling was applied to test the validity of the measurement model and hierarchical regression was used to test the key hypotheses.
Findings
DCs mediate the relationship between OL and CSRP. Moreover, CSRP significantly mediates the relationship between OL and innovation.
Originality/value
Drawing on the perspective of DCs, this research is among the first to offer new insights in a new context on what antecedent conditions lead to the successful implementation of organizational CSRP and how CSRP would, in turn, lead to subsequent innovation performance improvement.
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The purpose of this study is to investigate and analyze the knowledge management (KM) model of Nonaka and Takeuchi, focusing on institutional and infrastructure factors in a…
Abstract
Purpose
The purpose of this study is to investigate and analyze the knowledge management (KM) model of Nonaka and Takeuchi, focusing on institutional and infrastructure factors in a specific field of design offices in a product-oriented organization. In other words, this research does not intend to recreate the model of Nonaka and Takeuchi, but seeks to expand and modify this model according to the specific context and institutional and infrastructure factors that may specifically affect the effectiveness of the model.
Design/methodology/approach
This study used two distinct questionnaires, administered to the same set of respondents, to comprehensively address different dimensions of KM. The first questionnaire, focused on KM components, assessed aspects such as knowledge creation, sharing and utilization. The second questionnaire evaluated institutional and infrastructural factors critical to KM, covering dimensions like organizational culture, values, leadership, context, hardware, software and network systems. This dual-questionnaire approach is justified, as it allows for a detailed and differentiated analysis: one tool captures the operational aspects of KM, while the other explores the supporting infrastructure. This methodology ensures that the study accurately measures both the effectiveness of KM practices and the adequacy of the supporting environment, thus providing a robust assessment of the KM system.
Findings
This study identifies seven key factors influencing KM processes: organizational culture, values, leadership, context, hardware, software and network systems. These factors shape how knowledge is created, shared and used, and support proposed modifications to the Nonaka and Takeuchi KM model. Using the TOPSIS method, this study found that organizational context, culture and values rank above average, while KM policies are moderate, and information technology is below average in the design offices of a product-oriented organization in Tehran. Further research in different sectors could help validate these findings.
Originality/value
This study introduces a novel enhancement to the Nonaka and Takeuchi KM model by incorporating a comprehensive analysis of institutional and infrastructural factors. Unlike existing models, which primarily focus on generalized KM principles, this research uniquely integrates specific factors such as organizational culture, leadership and technological infrastructure. The originality of this work lies in its tailored approach for product-oriented organizations, offering a more precise and actionable framework for improving KM practices. This advancement not only deepens theoretical insights but also provides practical value by addressing the specific needs and dynamics of the target organizations.
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Mohammad Farahmand-Mehr and Seyed Meysam Mousavi
The purpose of this study is to investigate resource-constrained multi-project scheduling problems (RCMPSP) involving uncertainty in the form of time-dependent renewable resource…
Abstract
Purpose
The purpose of this study is to investigate resource-constrained multi-project scheduling problems (RCMPSP) involving uncertainty in the form of time-dependent renewable resource reliability. A key focus is to minimize the makespan (completion time) of projects when resources can become unavailable or fail over time at non-constant rates. Accounting for realistic resource reliability seeks to provide scheduling solutions that better reflect potential delays in practical multi-project environments.
Design/methodology/approach
A new discrete-time binary integer programming formulation of RCMPSP is expanded to include time-dependent resource reliability and simultaneously evaluate the time-dependent failure rate and constant repair rate of a resource. A new hybrid immune genetic algorithm with local search (HIGALS) is developed to solve this NP-hard problem. HIGALS incorporates a new coding mechanism, initialization method and local search operator.
Findings
A case study tests the proposed HIGALS approach. The validity of the mathematical model is confirmed by solving small-sized problems with GAMS software. The proposed HIGALS algorithm is validated by solving small-sized problems and comparing its solutions with GAMS. The superiority of HIGALS is demonstrated by comparing its solutions with six basic algorithms on medium- and large-sized problems. Results show that HIGALS outperforms existing algorithms, achieving an average reduction in makespan of over 11.79%, while maintaining the advantages of genetic, immune and local search algorithms and avoiding their disadvantages.
Practical implications
Considering time-dependent resource reliability can help project managers plan for disruptions and delays in resource-critical projects. HIGALS provides decision support for robust multi-project scheduling.
Originality/value
This study contributes to the field by investigating RCMPSP with time-dependent renewable resource reliability, which reflects real-world uncertainty more accurately. HIGALS presents a novel approach to balance intensification and diversification for this challenging problem.