درخت حوزه‌های تخصصی

This paper focuses on two main issues that are based on two important concepts: exponential Levy process and minimal entropy martingale measure. First, we intend to obtain risk measurement such as value-at-risk (VaR) and conditional value-at-risk (CvaR) using Monte-Carlo methodunder minimal entropy martingale measure (MEMM) for exponential Levy process. This Martingale measure is used for the exponential type of the processes such as exponential Levy process. Also, it can be said MEMM is a kind of important sampling method where the probability measure with minimal relative entropy replaces the main probability. Then we are going to obtain VaR and CVaR by Monte-Carlo simulation. For this purpose, we have to calculate option price, implied volatility and returns under MEMM and then obtain risk measurement by proposed algorithm. Finally, this model is simulated for exponential variance gamma process. Next, we intend to develop two theorems for implied volatility under minimal entropy martingale measure by examining the conditions. These theorems consider the asymptotic implied volatility for the case that time to maturity tends to zero and infinity.

This study explores the use of influence strategies and social mechanisms by the manufacturer to achieve supplier flexibility. Major components of marketing research of previous studies related to influence strategies and measures flexibility in the supply chain context are used. This empirical study utilized 300 survey samples from senior management at Small Medium Enterprises (SME)s. Results show that using influence strategies has positive effects on supplier mix flexibility. Furthermore, the effects of trust on shared vision is positive on manufacturer flexibility.

The current strategies of increasing work-life quality are being given special attention by both public and private organizations. These quality strategies have arisen because of the highly competitive environment. Also, a safe and healthy work environment that provides the opportunities for employees to enhance their loyalty, affiliation and love towards their work and organization is required in order to achieve the current and future aspirations of the organization. Accordingly, this study aims to explore the direct relationship between the variables: the strategy of work-life quality, strategic agility and sustainable competitive advantage, to identify their indirect relationships with their own dimensions. In order to achieve this, a questionnaire was distributed to both heads of companies and their deputies in large and medium Yemeni manufacturing companies, using a random sampling technique to reach 227 companies out of 554 by distributing 454 questionnaires for the selected population. Cronbach’s Alpha coefficient and exploratory statistics were carried out to identify the quality of measurements used to examine the proposed theoretical method using SEM. The results of the study are that there is a direct relationship between the variables. Additionally, there is an indirect relationship between the independent variable (strategy of work-life quality) and the dependent variable (sustainable competitive advantage) using strategic agility as a mediator in Yemeni large and medium manufacturing companies. These findings ensure the validity of the proposed theoretical model. In addition, it fills the knowledge gap regarding this issue and the findings highlight the competitive challenges that Yemeni companies must be aware of.