Traditionally, the inventory models available in literature assume that all articles purchased lot are perfect and demand is constant. However, there many causes provoke presence of defective goods dependent on some factors. In this direction, paper develops an economic order quantity (EOQ) model for imperfect quality items, taking into account ones sent as a single to repair shop reworking. Af...

Establishing test marks and reporting them to students is a difficult task for key medical educators. Failing a test is usually an unpleasant experience for any student. Therefore, medical educators must ensure the “reasonableness” of the pass mark and additionally, the quality of all test items. A poorly established pass mark and/or defective items may increase the number of students who fail ...

Due to the computerization of assessment tests, the use of Item Response Theory (IRT) has become commonplace for educational assessment development, evaluation, and refinement. When used appropriately by a Learning Management System (LMS), IRT can improve the assessment quality, increase the efficiency of the testing process, and provide in-depth descriptions of item and test properties. This p...

Classiication of real-time X-ray images of randomly oriented touching pistachio nuts is discussed. The ultimate objective is the development of a system for automated non-invasive detection of defective product items on a conveyor belt. We discuss the extraction of new features that allow better discrimination between damaged and clean items (pistachio nuts). This feature extraction and classii...

In the present paper we investigate a EOQ model for imperfect items under time variable linear demand. The defective items is being screened out by a 100 % screening process and then sold in a single batch by the end of the 100% screening process with a salvage price. The unsold perfect item during the cycle is sold at a different salvage price at the end of cycle. Two different types for cost ...

Production systems with scrapped and rework items have recently become an interesting subject of research. While most attempts have been focused on finding the optimal production quantity in a simple production system, little work appears on a joint production environment. In this research, two joint production systems in a form of multiproduct singlemachine with and without rework are studied ...

This paper derives optimal production-shipment policy for a single-producer multi-retailer integrated inventory model with rework. We assume that a product is manufactured by a producer. All items are screened for quality assurance. Random defective items will be picked up and reworked in the same cycle when regular production ends. Upon entire lot is quality assured, multiple shipments are del...

To overcome stress, such as resource limitation, an organism often needs to successfully mediate competition with other members of its own species. This may favor the evolution of defective traits that are harmful to the species population as a whole, and that may lead to its dilution or even to its extinction (the tragedy of the commons). Here, we show that this phenomenon can be circumvented ...