Search results

The purpose of this article is to investigate the return associated with a Canadian dollar (C$) investment in the USA under passive, random walk, value at risk, and Sharpe ratio strategies.

To comply with the purpose, this paper used a GARCH model, and used, as basic data, daily C$ exchange rates and weekly US and Canadian interest rates on 90‐day CDs, from January 2 to November 26, 2004.

The empirical results suggest that currency returns are positively correlated to risk; and that the return provided by the random walk strategy beats the other strategies considered in this paper.

The findings suggest that currency investment is similar to other forms of investment, since it shows a positive relationship between risk and return. It also supports the long‐standing belief that sophisticated strategies do not beat simple‐minded approaches such as a random walk strategy.

This paper uses a utility function to investigate the response of investors to risk and return under different aversion scenarios.

Two-stage production systems including a processing shop and an assembly stage are widely used in various manufacturing industries. These two stages are usually studied independently which may not lead to ideal results. This paper aims to deal with a two-stage production system including a job shop and an assembly stage.

Some exact methods are proposed based on branch and bound (B&B) approach to minimize the total completion time of products. As B&B approaches are usually time-consuming, three efficient lower bounds are developed for the problem and variable neighborhood search is used to provide proper upper bound of the solution in each branch. In addition, to create branches and search new nodes, two strategies are applied including the best-first search and the depth-first search (DFS). Another feature of the proposed algorithms is that the search space is reduced by releasing the precedence constraint. In this case, the problem becomes equivalent to a parallel machine scheduling problem, and the redundant branches that do not consider the precedence constraint are removed. Therefore, the number of nodes and computational time are significantly reduced without eliminating the optimal solution.

Some numerical examples are used to evaluate the performance of the proposed methods. Comparison result to mathematical model (mixed-integer linear programming) validates the performance accuracy and efficiency of the proposed methods. In addition, computational results indicate the superiority of the DFS strategy with regard to CPU time.

Studies about the scheduling problems for two-stage production systems including job shop followed by an assembly stage traditionally present approximate method and metaheuristic algorithms to solve the problem. This is the first study that introduces exact methods based on (B&B) approach.

This paper aims to address a distributed assembly permutation flow-shop scheduling problem (DAPFSP) considering budget constraints and factory eligibility. The first stage of the considered production system is composed of several non-identical factories with different technology levels and so the factories' performance is different in terms of processing time and cost. The second stage is an assembly stage wherein there are some parallel work stations to assemble the ready parts into the products. The objective function is to minimize the maximum completion time of products (makespan).

First, the problem is formulated as mixed-integer linear programing (MIP) model. In view of the nondeterministic polynomial (NP)-hard nature, three approximate algorithms are adopted based on variable neighborhood search (VNS) and the Johnsons' rule to solve the problem on the practical scales. The proposed algorithms are applied to solve some test instances in different sizes.

Comparison result to mathematical model validates the performance accuracy and efficiency of three proposed methods. In addition, the result demonstrated that the proposed two-level self-adaptive variable neighborhood search (TLSAVNS) algorithm outperforms the other two proposed methods. Moreover, the proposed model highlighted the effects of budget constraints and factory eligibility on the makespan. Supplementary analysis was presented by adjusting different amounts of the budget for controlling the makespan and total expected costs. The proposed solution approach can provide proper alternatives for managers to make a trade-off in different various situations.

The problem of distributed assembly permutation flow-shop scheduling is traditionally studied considering identical factories. However, processing factories as an important element in the supply chain use different technology levels in the real world. The current paper is the first study that investigates that problem under non-identical factories condition. In addition, the impact of different technology levels is investigated in terms of operational costs, quality levels and processing times.

Nowadays, the topic of supply chain network design has gained significant attention as a critical area within the field of supply chain management. Researchers have dedicated their studies to exploring market competitiveness and pursuing greater benefits. This paper presents a multi-objective mathematical model aimed at designing a competitive and sustainable closed-loop supply chain network specifically for perishable products. The proposed model takes into account the competition between two supply chains, considering various factors such as environmental impacts, social performance and resilience.

To address the competitive nature of this model, this study introduces a two-stage approach. In the initial stage, this study uses a game theory approach to determine equilibrium values for competitive decisions. This allows establishing a fair and balanced playing field between the two supply chains. Subsequently, due to the complexity of the proposed model, this study uses a multi-objective metaheuristic algorithm based on the Non-dominated Sorting Genetic Algorithm. This algorithm serves as a robust computational tool to effectively solve the network design problem and optimize the desired objectives.

To evaluate the effectiveness of the proposed model and solution approach, this study provides a numerical example. Through graphical and statistical analysis, this study assesses the performance of the model and its ability to achieve the desired objectives. The results and charts obtained demonstrate the strong performance and efficacy of the proposed model in effectively addressing the challenges associated with designing a competitive and sustainable closed-loop supply chain network for perishable products.

By considering the various factors at play and incorporating them into the model, this study aims to contribute to the existing body of knowledge in supply chain management. The findings provide valuable insights into designing supply chain networks that not only enhance competitiveness but also promote sustainability.

This study represents one of the initial investigations into the evaluation of competitive supply chains, taking into account crucial factors such as environmental, social and resilience. A supply chain that considers these factors can attain greater durability and competitiveness compared to other supply chains.

The purpose of this paper is to frame Khaled Hosseini's novels, The Kite Runner and A Thousand Splendid Suns, as literature to expand and enhance the American secondary curriculum with multicultural themes based on Afghanistan as a geographical and cultural place in a dynamic, diverse, and complex world more mediated than ever before by computer technologies.

The methodological approach to the study is a synthesis of geographic education grounded in the concept of place and diversity pedagogy.

Khaled Hosseini's web site has become the cyber place where hundreds of readers from around the world come to express their deep emotional reactions to The Kite Runner and A Thousand Splendid Suns. At the same time, that so many diverse international readers are responding favorably to Hosseini's novels, his works are being censored in classrooms in the USA. The research outlines geographical and cultural geographic features of Afghanistan – a place torn by military efforts of several nations. In the context of diversity pedagogy, the power of the novels portrays “difference,” yet humanity in need of understanding. Further attention is given to the censorship of ideas in American education, with Hosseini's books as one example.

This paper frames Hosseini's novels as place‐based literature illustrating the homeland of Afghanistan now more accessible than ever before to international and US classrooms.

This paper aims to introduce a new structure for coaxial magnetic gears.

The study discusses the design and electromagnetic modeling of a triple-speed coaxial magnetic gear (TSCMG) for three different levels of torques in special applications such as wind energy conversion and electrical vehicles. The proposed TSCMG consists of inner, middle and outer rotor, which has one rotor more than its conventional counterpart. The suggested TSCMG’s related equations such as transform ratio and torque are calculated, then TSCMG is simulated in a finite element environment. A comprehensive study has been done on TSCMG, and results are compared with two other magnetic gears with the same volume but two speeds.

The obtained results show that the proposed structure for TSCMGs is significantly practical and applicable in higher ranges of torques. Finally, an experimental TSCMG is prototyped to verify the results.

The achievements are excellent and confirm that TSCMG can be used as powerful equipment in a wide range of application like permanent wind turbines to generate electricity in 24 h per every single day.

The purpose of this paper is to investigate the natural convection behavior of nanofluids in an enclosure. The enclosure is a 3D capsule with curved boundaries filled with TiO₂-water nanofluid.

In this paper, a multiple relaxation times lattice Boltzmann method (MRT-LBM) has been used. Two-component LBM has been conducted to consider the interaction forces between nanoparticles and the base fluid.

Results show that the enhanced Nusselt number (Nu*) increases with the increase in volume fraction of nanoparticles (ϕ) and Ra number and decrease of nanoparticle size (λ). Additionally, the findings indicate that increasing volume fraction beyond a certain value decreases Nu*.

This paper presents a MRT model of lattice Boltzmann in a 3D curved enclosure. A correlation is also presented based on the current results for Nu* depending on Ra number, volume fraction and size of nanoparticles. Furthermore, a comparison for the convergence rate and accuracy of this model and the SIMPLE algorithm is presented.

Nowadays, the risk assessment and reliability engineering of various production processes have become an inevitable necessity. Because if these risks are not going to be evaluated and no solution is going to be taken for their prevention, managing them would be really hard and costly in case of their occurrence. The importance of this issue is much higher in producing healthcare products due to their quality's direct impact on the health of individuals and society.

One of the most common approaches of risk assessment is the failure mode and effects analysis (FMEA), which is facing some limitations in practice. In this research, a new generalized multi-attribute failure mode analysis approach has been proposed by utilizing the best–worst method and linguistic 2-tuple representation in order to evaluate the production process of hemodialysis solution in a case of Tehran, Iran.

According to the results, entry of waste to the mixing tanker, impurity of raw materials and ingredients and fracture of the mixer screw have been identified as the most important potential failures. At last, the results of this research have been compared with the previous studies.

Some reinforcement attributes have been added to the traditional FMEA attributes in order to improve the results. Also, the problems of identical weights for attributes, inaccuracy in experts' opinions and the uncertainties in prioritizing the potential failures were improved. Furthermore, in addition to the need for less comparative data, the proposed approach is more accurate and comprehensive in its results.

This chapter explores the determinants of satisfaction of the Islamic microcredit borrowers in Bangladesh. A total of 245, mostly educated and young, borrowers of rural development scheme, the largest Islamic microcredit institution (MCI) in the world, were included in a survey using a structured questionnaire. Factors were extracted using exploratory factor analysis. Multiple regression analysis was conducted to identify influential determinants of satisfaction of microcredit borrowers. Borrowers have identified the activities and interaction in the “center,” which includes weekly/monthly meetings, investment-related training, and group performance review, as the most vital factor influencing their overall satisfaction. Competence of the microcredit staffs and officials is the second important determinant. Trust plays the next important role in overall satisfaction of the borrowers with the Islamic microcredit institutions. Convenience, of applying for loan, getting an approval, and paying instalments, is the other influential determinant of the borrower’s satisfaction. The findings imply that given the competition and social need of the Islamic microcredit institutions globally, policymakers must ensure greater investment in human capital, in creating awareness about products and services of the Islamic microcredits, and in initiating a prudent change in the regulation so that Islamic microcredit can become a tool for sustainable socioeconomic development. Use of a proper marketing strategy can also help the MCIs to support the financial inclusion policy of the government. Satisfaction of the borrowers of the Islamic microcredit institutions is yet to arrive in Islamic marketing literature. The proposed borrower-centric model can help reduce poverty and the internal loan-shark problem through adequate engagement of relevant stakeholders.

The purpose of this paper is to evaluate the impact of Entrepreneurship Education Programs (EEPs) from students’ and educators’ viewpoint to improve the quality of EEPs.

This research applies a qualitative-quantitative methodology. Its sample is included 291 students were selected randomly and 35 educators were chosen by convenience technique from universities of Applied Science and Technology of Iran.

The results revealed that essence of EEPs had a positive direct effect on objectives and content of EEPs; objectives and content of EEPs had a positive direct effect on methods of EEPs; essence of EEPs had a positive direct effect on impact of EEPs; and essence of EEPs had a positive indirect effect on methods through objectives and content based on students’ and educators’ perspective. Moreover, as opposed to educators’, students believed that methods of EEPs have not a positive direct effect on impact, while educators were opponent to students approach about the positive direct effect of essence of EEPs on methods.

The study was limited to Applied Science and Technology universities were selected by convenience sampling method. Similar studies in other universities are needed to be conducted by simple random sampling to evaluate EEPs.

The study recommends policy-makers to be aware of students’ needs of EEPs’ methods, as well inform educators about effective and initiative methods.

Evaluating impact of EEPs based on demand and supply-side viewpoint is the first study conducted in Applied Science and Technology universities of Iran.