Background: Smartphones pervasiveness has captured people with the ability to search for information, communicate more easily, and make our day-to-day jobs easier. On other hand, excessive smartphone use can also lead serious musculoskeletal consequences including neck pain disability. Objective: To determine correlation of Text-Neck-Syndrome addiction during COVID-19 pandemic. Methods: The cro...

In this paper we consider a single machine scheduling problem with deteriorating jobs. By deteriorating jobs, we mean that the processing time of a job is a simple linear function of its execution starting time. For the jobs with chain precedence constraints, we prove that the weighted sum of squared completion times minimization problem with strong chains and weak chains can be solved in polyn...