Observational studies comparing groups or populations to evaluate services or interventions usually require case-mix adjustment to account for imbalances between the groups being compared. Simulation studies have, however, shown that case-mix adjustment can make any bias worse. One reason this can happen is if the risk factors used in the adjustment are related to the risk in different ways in ...

Mixed-integer linear programming is adopted to translate the routing of service operation vessels that support logistic aspects maintenance offshore floating wind farms into mathematical language. The models attempt help decision-makers by providing quantified tools screen out optimal planning for preventive maintenance. search base location, vessel’s per day, capacity, and vessel fleet composi...

The passenger line planning is a process of strategic long-term decision-making problem in the field of railway passenger planning. A line is a route between starting point and destination with certain stops, which has a certain frequency of train schedule. A new solution based on decomposition algorithm has been proposed in this paper, which is defined in a master problem and two sub problems....

Lean Manufacturing concept is well described in the literature in the context of low-mix high-volume production. There are numerous case studies proving outstanding benefits of implementation Lean principles. Nowadays enterprises have to face the problem of high variety of products and dynamically changing demand. Lean tools and methods known from repetitive production do not always fit to high...

Robust supplier selection problem, in a scenario-based approach has been proposed, when the demand and exchange rates are subject to uncertainties. First, a deterministic multi-objective mixed integer linear programming is developed; then, the robust counterpart of the proposed mixed integer linear programming is presented using the recent extension in robust optimization theory. We discuss dec...

in this paper, a hybrid method for limited resource allocation and leveling in complex multi-stage, multi-product and multi-period production planning problems with aim of lot-size determination and total cost minimization has been proposed. this problem consists of multiple products with sequential production processes that are produced in different periods to meet the customers demand. by det...

Motivated by what is required for real-time path planning, the paper starts out by presenting RMPD, a new recursive “local” planner founded on the key notion that, unless made necessary by an obstacle, there must be no deviation from the shortest path between any two points, which would normally be a straight line path in the configuration space. Subsequently, we increase the power of RMPD by i...

Electricity demand is forecasted to double in 2035, and it is vital to address the economicsof electrical energy generation for planning purposes. This study aims to examine the applicability ofGravitational Search Algorithm (GSA) and the newly improved GSA (IGSA) for optimization of themixed-integer non-linear electricity generation expansion planning (GEP) problem. The performanceindex of GEP...

Video-game designers often tessellate continuous 2dimensional terrain into a grid of blocked and unblocked square cells. The three main ways to calculate short paths on such a grid are to determine truly shortest paths, shortest vertex paths and shortest grid paths, listed here in decreasing order of computation time and increasing order of resulting path length. We show that, for both vertex a...