In this paper, we consider a permutation flow shop scheduling problems with n jobs and m machines. The jobs have arbitrary processing times and due dates. Our objective is minimizing the total earliness and tardiness of all jobs. We develop a genetic algorithm to solve this problem. The performance of the algorithm is evaluated through computational experiments.

Nowadays, scheduling problems have a considerable application in production and service systems. In this paper, we consider the scheduling of n jobs on a single machine assuming no machine idleness, non-preemptive jobs and equal process times. In many of previous researches, because of the delivery dalays and holding costs, earliness and tardiness penalties emerge in the form of linear combinations in objective functions. However, minimizing the weighted quadratic earliness and tardiness penalties is considered in this paper. A branch and bound algorithm including some dominance rules, lower bounds and upper bounds is proposed to solve the problem. Finally, the efficiency of proposed method is proved via some test problems.

In order to evaluate the grain yield and other agronomic and qualitative characteristics of foreign corn hybrids, this experiment was conducted with 13 new maize hybrids and two commercial hybrids (BC-62, BC632, BC-621, BC628, BC-512, BC-595, PL-472, BC-525, Valbum, BC-626, BC-585, Torro, Simon, KSC 704 and KSC 703), in a randomized complete block design with four replications in Mahdasht research station in 2016. Analysis of variance showed that the effect of cultivar on grain yield, yield components and grain yield was significant at 1% probability level. The BC-621 was the best hybrid with a 100 seed weight of 359 gr, very low percentage of cob weight (12. 4%) and high grain yield (15. 060 t/ha) and shorter physiological maturation time (137 days). The BC-512 and BC-626 hybrids with physiological ripening time (138 and 136 days) and 1000 kernel weight (331 and 324 g) and cob (13. 5% and 16. 7%) and grain yields (14. 430 and 13. 830 t/h) were superior hybrids. The Torro hybrid was also a good cultivar with a 1000 kernel weight of 396 grams and a cob percentage (15 %) and a grain yield of 12. 980 t/h and a physiological ripening time of 137 days. These hybrids are high-yielding and compatible and very suitable for cultivation in the temperate regions of Kermanshah province. These hybrids were a very suitable in terms of type, plant height and low leaf shade in the plant, and the ability to penetrate sunlight on the lower leaves. The four hybrids yields were about 3 to 5 t/h higher than the KSC704 and KSC703 controls. Also they had more tolerance to corn common disease.

Domsiah is one of local rice cultivar with best quality in Iran, but it is nearly late with long awn. This study was conducted to induce earliness and awnless characterstics in Domsiah cultivar from 1995 to 1999. The seeds were irradiated with gamma rays at 100, 200 and 300 Gray, and Dimethyl Sulfate (DMS) at 0.1%, 0.2% and 0.3% (for 24 hrs. in room temperature), separately. At the end of first year of study, main panicels of some randomly selected plant were harvested and planted at M2 generation as a panicle-to-row. Results showed no sigificant varition among the DMS treatments; hence these treatments were removed from the study. Four early mutant populations (E1 to E4) were obtained from treatments of gamma rays at M2 generation. These mutant populations showed segregation for maturity. Meanwhile, the E1 population showed segragation for awnless. The plant height, culm number, maturity and panicle length were studied in mutant lines at M3generation. The E3line was 15 days earlier than control at M4 generation. The plant height of this line was significantly different compared to control, the awnless mutant line was also shorter and earlier. In order to study some morphological characteristics and yield at M 5generation, the E3and awnless mutant lines were planted in randomized completed block design with three replications in Rasht and Tonekabon in 1999 and 2000. The characteristics under study were included: plant height, culm number, peduncle, second internode length, flag leaf length and width, days to panicle emergence (DPE), days to maturity (DMA), panicle length, grain length and width, spikelet fertility, grain no. per panicle, grain yield, 100-grainweight, amylose (%), gel consistency and gelatination temperature. There were no significant differences in second internode length, DPE, spikelet fertility, amylose %, gel consistency and gelatination temperature. Generally, the correlation coefficient between DPE and DMA in rice is positive and significant, however, it was found non significant in this study. Because of highly significant correlation (r =0.7**) between yield and l00-grainweight, it is possible to improve grain yield through 100-grainweight. Although, there was not a significant difference between early mutant and awnless lines in DMA, however, 100 grain weight and no. of grain per panicle in awnless mutant line were higher than in early mutant line. These two mutant lines has significant difference for DMA compared to control i.e. they were 13 days earlier than control.    

This experiment was conducted to determine gene action for different traits of chickpea including days to 50% flowering, days to maturity, plant height, 100-seeds weight, number of pods per plant and seed yield. Five genotypes including Arman, Hashem, ILC588, ICCV2 and ILC3279 were selected and crossed with each other. Four generations of each cross along with parents were evaluated in a randomized complete block design with three replications. In each replication 15 plants for P1, P2 and F1, 30 plants for BC1 and BC2, and 60 plants for F2 were evaluated for all traits. Joint scaling test and chi-square test were used to estimate the gene action. The Chi-square of simple three parametric models was significant for all traits except for plant height, indicating the presence of non allelic-interactions in the inheritance of these traits in chickpea. Both additive and dominant genetic effects were significant for days to 50% flowering, days to maturity, number of pods per plant and seed yield. In addition, presence of high amount of dominant effect and dominant × dominant interactions suggests the importance of non-additive genetic effects for these traits in chickpea. Therefore, selection for these traits in early generations could not be effectively successful. However, additive genetic effects play an important role in the inheritance of plant height and 100-seed weight, promising selection for these traits in early generations during the process of chickpea breeding.

To study inheritance of morphological traits associated with earliness and their relationship with yield, six genotypes of cotton were studied in a half diallel cross in 2003 in Darab. Fifteen Fl and six parents were evaluated in a complete block design with three replications. The results showed that differences among treatments were significant for seed cotton yield, earliness, plant height, date of first squire and mean maturity data. General and specific combining ability (GCA and SCA) effects were estimated by the method 2 of the Griffing's model I.Mean square of general combining ability (GCA) was significant for all studied traits. Specific combining ability (SCA) was significant only for yield. GCA/SCA ratio was significant for all studied traits except for yield. Determination of genetic parameters, statistical indices and graphical analysis by Jinks-Hayman method showed that gene actions for yield and earliness were over-dominance, while plant height, days to first squire and mean maturity data showed partial dominance. All of the traits had high board sense heritability: Narrow sense heritability was also high for all traits except yield.

Nowadays, flexible manufacturing system (FMS) is introduced as a response to the competitive environment. Scheduling of FMS is more complex and more difficult than the other scheduling production systems. One of the main factors in scheduling of FMS is variable time of taking orders from customers, which leads to a sudden change in the manufacturing process. Also, some problems are created in production system such as waste, earliness and tardiness costs, and increase inventory. In this paper, a part of flexible manufacturing system where products are produced in two stages and in multiple repositories, is known as a bottleneck. In this study, a mathematical model for scheduling of this problem considering the limitations of the production system such as flow rate and output reservoirs, variable time order entry, waste resulting from the cessation of production, and the storage capacity of reservoirs is developed. Then, the proposed model has been solved by GAMS software. Results confirm the validity of the proposed model.

Cotton is an important fiber crop and used to produce fibers and oil. Evaluating morphologic traits of cotton is very important and can be used for the selection of better cultivars. This study was conducted in the Moghan Agricultural Research Station affiliated with the Ardabil Agricultural and Natural Resources Research and Training Center, Iran. In this study, 35 cultivars of cotton were evaluated for fiber-and yield-related traits during two consecutive years. We found that fiber quality and seed cotton traits were significantly affected by plots and cultivars over two years. Among the cultivars, the highest number of the bolls, boll weight, first picking yield, total yield, fiber strength, fiber traction, and fiber percentage were 24.5 g, 6.30 g, 3454 kg/ha, 5431 kg/ha, 34.5 g/tex, 7.30%, and 45.80% observed in cultivar Shayan, while the second picking yield, earliness percentage, and fiber fineness were 2323.3 kg/ha, 73.5%, and 4.55 μg/in obtained in cultivars Varamin, Avangard, and Armaghan, respectively. Based on the ward’s cluster analysis, the cotton cultivars were grouped into three different clusters. The cultivars in Cluster 3 including Nazilli, No.228, No.200, B557, Armaghan, Golestan, and Shayan are superior in terms of their number of the boll, boll weight, earliness percentage, fiber percentage, fiber length, fiber fineness, fiber strength, fiber traction, and yield performance.

This study presents an enhanced genetic algorithm (E-GA) to minimize earliness/tardiness costs in the job shop environment. It considers an unrelated parallel machine scheduling problem with a limit on maximum tardiness levels. This problem is motivated by the experience of one of the authors in a job shop supporting the local aircraft industry that requires strict control on delivery times. Current literature does not consider this critical restriction and unsuccessfully tries to deal with them using higher penalty costs. The proposed method uses the design of experiment (DOE) concept while optimizing the GA operators. Furthermore, it improves the initial solution using a hybrid dispatch rule through a strategic combination of construction and improvement heuristics. The model was applied to a local job shop. The results indicate that E-GA provides a schedule with lower cost and reduced computational time compared to existing dispatch rules in the literature and existing algorithms (OptQuest).