The resilience of industry has caught much attention since the outbreak COVID-19 pandemic. Most literature argues that spatial concentration is beneficial to industrial development, but few reports discuss its impact on survival from a long-term perspective, namely resilience. Therefore, this study tries answer whether patterns performance through investigating longevity production sites. We ta...

abstract portfolio definition is the most important decision for individuals and legal persons that invest in stock. the main objective of this paper is study and determination of optimal portfolio for stock of active food industrial company in tehran stock based on value at risk (var) index. for this purpose, we used weekly static of stock of active food industrial company in tehran from bahma...