In this paper, we present a genetic algorithm approach that considers the single machine scheduling problem. There are n jobs, in which each job j ( 1 2 j n = , ,..., ) has a normal processing time j p , a due date j d , earliness penalty j α , and tardiness penalty j β . The objective is to find the sequence of jobs that minimizes the weighted sum of earliness and tardiness penalty costs, with...

This paper focuses on production scheduling in a semiconductor wafer fab producing multiple product types that have different due dates and different process flows. In the wafer fab, wafer lots are processed on serial and batch processing workstations, each of which consists of parallel identical machines. Machines in serial processing workstations process wafer lots one by one, while those in ...

Apatite is increasingly used in sedimentary provenance studies. However, detrital apatite U–Pb geochronology can be challenging due to the presence of non-radiogenic Pb, its intermediate closure temperature (~350–550°C) and/or age-resetting by metamorphic/metasomatic processes. The Lu–Hf system has a higher (~675–750°C) and is, therefore, more robust thermal resetting. Here we present first age...

in order to study the effects of fall planting dates on yield and yield components of six cumin (cuminum cyminum l.) ecotypes an experiment was arranged in a randomized complete block design as a split-plot with three replications during 2007-08 growing season at the agricultural research station of ferdowsi university of mashhad. three planting dates (18 oct. (first), 8 nov. (second) and 29 de...

In this paper, we consider distributed versions of a modified shifting bottleneck heuristic for complex job shops. The considered job shop environment contains parallel batching machines, machines with sequence-dependent setup times and reentrant process flows. Semiconductor wafer fabrication facilities are typical examples for manufacturing systems with these characteristics. The used performa...

This paper addresses the Tardy/Lost penalty minimization with common due dates on a single machine. According to this performance measure, if the tardiness of a job exceeds a predefined value, the job will be lost and penalized by a fixed value. Initially, we present a 2-approximation algorithm and examine its worst case ratio bound. Then, a pseudo-polynomial dynamic programming algorithm is de...