On Using the Linear Programming Relaxation of Assignment Type Mixed Integer Problems -- Contributions to Duality Theory of Certain Non-Convex Optimization Problems -- Multistate Reliability Problems for GSP-Digraphs -- Improved Bounds for the Sn /n Problem -- Selection of Solutions by Algorithms -- to Stochastic Scheduling Problems -- Aspects of Optimization in Automobile Insurance -- GERT Networks with Tree Structure: Properties, Temporal Analysis, Cost Minimization and Scheduling -- On Stability of Linear Time-Varying Infinite Dimensional Systems -- Optimal Stopping and Leavable Gambling Models with the Average Return Criterion -- A Closed Network Model. for I/O Subsystems.