We investigate the single machine scheduling problem with job release dates and due dates, and multiple planned unavailability time periods. This problem arises in the context of machine scheduling with planned preventive maintenance and might be viewed as a generalization of   several fundamental single-machine problems. The contribution of this paper is two-fold. First, we propose a new lower bound that is based on the concept of semi-preemptive scheduling. Second, we propose an exact algorithm that requires solving a sequence of one-machine problems without availability constraints.

The purpose of this paper is to analyses the productivity growth performance of the different sectors of the Saudi economy.  In particular, this paper tries to look at the following questions:
(1) What does productivity growth performance look like in the different sectors of the economy? (2) What are the relative contribution labor and capital to sectoral growth?
(3) What policy suggestions could be made to enhance productivity growth and increase its role in the overall economic growth and diversification of the economic base of the Saudi economy?  

As the world’s largest exporter of crude oil and natural gas liquids, with the world’s largest reserves of these products, the Kingdom of Saudi Arabia is understandably quite dependent upon oil export revenues to fuel its economy. 
            Attempts to diversify the Kingdom’s economic base have been successful, but the fact remains that the Saudi economy is still quite dependent on crude oil and downstream refined petroleum and petrochemical products.

Using a Vector Auto-Regression approach (VAR), this paper attempts to analyze the dynamic behavior of the non-oil GDP of Saudi Arabia for the period 1963-2004.

Using A vector auto-regression approach (VAR), this paper  mainly studys the effect of the government domestic expenditure, and other variables, on the behavior of the private consumption in Saudi Arabia during the period 1960-1997 by analyzing the response of the latter to the structural shocks in the former.

This study specifies a modified version of the monetary approach to the balance of payments (MABP) model with free capital flow and fixed exchange rates for Saudi Arabia, and tests the independence of monetary policy of its central bank using annual data from 1960 to 1994. Further, capital flight and speculative inventory behavior of importers of consumer and capital goods in Saudi Arabia are also tested to the expected exchange rate depreciation during the periods of exchange turmoil against the riyal.

The purpose of this study was to evaluate in vitro the effect of different variables (delivery system, surface contact with the irrigant, the frequency of changing the irrigant and the total volume of the irrigant) of sodium hypochlorite on the elimination of E. faecalis using rotary instrumentation and intermittent passive ultrasonic irrigation (IPUI). MATERIALS and METHODS: Sixty extracted single-rooted teeth were instrumented up to size 20 K-file, then inoculated with E. faecalis.