A considerable problem in competitive trade world is choosing the best supply chain. As a result in much more serious circumstances of competitions looking for the best supplier for manufacturing, for preparing raw material, is very significant. Meantime suppliers have different scenarios to be fulfilled, such as changing selection variables like lead-time, transportation cost and transportatio...

The cell formation (CF) is one of the most important steps in the design of a cellular manufacturing system (CMS), which it includes machines’ grouping in cells and part grouping as separate families, so that the costs are minimized. The various aspects of the problem should be considered in a CF. The machine reliability and the tool assigned to them are the most important problems which have t...

We develop and empirically implement a model of optimal replacement of rental equipment and apply the model to derive detailed optimal replacement strategies for five different types of rental machinery: 1) excavators, 2) high reach forklifts, 3) skid steers, 4) scissor lifts, and 5) telescopic booms. Using data on actual replacements, revenues, maintenance costs, new machine prices and resale ...

In every field of our real life situations, we deal with a replacement problem, when some items such as machines, medical equipment, military tank, electric bulb etc. or workers need to replace due to their decreased efficiency, failure or break down. To get a more realistic view of a replacement problem, here, we consider that the capital cost ( C ~ ), scrap value or resale value ( S ~ ), main...

In Operations Research, the equipment replacement process is usually modeled in discrete time. The optimal replacement strategies are found from discrete (or integer) programming problems, well known for their analytic and computational complexity. An alternative approach is represented by continuous-time vintage capital models that explicitly involve the equipment lifetime and are described by...

contraceptive patches have become a frequently used contraceptive method. we present a mathematical model that describes the serum concentration profiles of norelgestromin (ngmn) and ethinylestradiol (ee) released from the contraceptive patch ortho evra®. we propose a simple one-compartment model based on pharmacokinetics data reported in previous studies. the model assumes a time-dependent rel...

In the present academic and engineering fields, every measure function of product reliability is modeled estimated from statistical perspective. These indicate that there universally exist differences in reliabilities new identical products survive burn-in test. On basis products, designing through-life maintenance models for managing different a very practical topic fields. this study, random ...

Cotton is one of the major crops cultivated in the Texas Rolling Plains region, and it is a major contributor to the regional economy. Cotton cultivation in this region is facing severe challenges due to an increase in the frequency of droughts and a projected decrease in rainfall in the future. Development and evaluation of deficit irrigation strategies for this region could potentially conser...

Today power consumption is considered to be one of the important issues. Therefore, its reduction plays a considerable role in developing systems. Previous studies have shown that approximately 50% of total power consumption is used in cache memories. There is a direct relationship between power consumption and replacement quantity made in cache. The less the number of replacements is, the less...