background: to extract utility values of diabetic retinopathy on a perfect health and perfect vision scales for iranians with both types diabetes. methods: in this investigation, 150 untreated patients with diabetic retinopathy consecutively were examined and interviewed in farabi eye hospital, tehran, iran, a tertiary referral center in the iranian health care system. utility values based on p...

in this paper, we present a genetic algorithm (ga) for optimization of a multi-mode resource constrained time cost trade off (mrctct) problem. the proposed ga, each activity has several operational modes and each mode identifies a possible executive time and cost of the activity. beyond earlier studies on time-cost trade-off problem, in mrctct problem, resource requirements of each execution mo...

In this paper, we present a genetic algorithm (GA) for optimization of a multi-mode resource constrained time cost trade off (MRCTCT) problem. The proposed GA, each activity has several operational modes and each mode identifies a possible executive time and cost of the activity. Beyond earlier studies on time-cost trade-off problem, in MRCTCT problem, resource requirements of each execution mo...

P and time are integral dimensions of virtually any decision. To treat them together, we consider the prospect of receiving outcome x with a probability p at time t. We define risk and time distance, and show that if these two distances are traded off linearly, then preferences are characterized by three functions: a value function, a probability discount rate function, and a psychological dist...

time, cost and quality are considered as the main components in managing each project. previous researches have mainly focused on the time-cost trade-off problems. recently quality is considered as the most important factor in project�s success, which is influenced by time acceleration that is the less time is spent the more success is gained. in time-cost-quality trade-off problems, each act...

Time-cost trade-off is one of the most important subjects in project management and of interest to contractors. The goal of time-cost trade-off is sensivity analysis of project costs to changes in activity duration in order to obtain the best combination of activity duration decrease, in a way that the sum of project costs is minimized. In the heuristics presented in this area, time crashing is...

Time-cost trade-off is one of the most important subjects in project management and of interest to contractors. The goal of time-cost trade-off is sensivity analysis of project costs to changes in activity duration in order to obtain the best combination of activity duration decrease, in a way that the sum of project costs is minimized. In the heuristics presented in this area, time crashing is...