Improved Scatter Search Algorithm for Multi-skilled Personnel Scheduling of Ship Block Painting

This paper focuses on the optimization method for multi-skilled painting personnel scheduling.The budget working time analysis is carried out considering the influence of operating area,difficulty of spraying area,multi-skilled workers,and worker’s efficiency,then a mathematical model is established to minimize the completion time. The constraints of task priority,paint preparation,pump management,and neighbor avoidance in the ship block painting production are considered. Based on this model,an improved scatter search(ISS)algorithm is designed,and the hybrid approximate dynamic programming(ADP)algorithm is used to improve search efficiency. In addition,the two solution combination methods of path-relinking and task sequence combination are used to enhance the search breadth and depth. The numerical experimental results show that ISS has a significant advantage in solving efficiency compared with the solver in small scale instances;Compared with the scatter search algorithm and genetic algorithm,ISS can stably improve the solution quality. Verified by the production example,ISS effectively shortens the total completion time of the production,which is suitable for scheduling problems in the actual painting production of the shipyard.

Comparing the Diagnostic Criteria for Gestational Diabetes Mellitus of World Health Organization 2013 with 1999 in Chinese Population

INTRODUCTION Gestational diabetes mellitus （GDM） was earlier defined as ＂hyperglycemia first recognized during pregnancy＂ and has more recently been described by American Diabetes Association （ADA） （2012） as diabetes diagnosed during pregnancy that is not clearly overt diabetes. The hyperglycemia and adverse pregnancy outcomes study （HAPO） demonstrated that the risk of adverse maternal,fetal,and neonatal outcomes continuously increase as a function of maternal glycemia at 24-28 weeks,even within ranges previously considered normal for pregnancy.

Excessive gestational weight gain in early pregnancy and insufficient gestational weight gain in middle pregnancy increased risk of gestational diabetes mellitus

Background:Gestational weight gain(GWG)is associated with the risk of gestational diabetes mellitus(GDM).However,the effect of weight gain in different trimesters on the risk of GDM is unclear.This study aimed to evaluate the effect of GWG on GDM during different trimesters.Methods:A birth cohort study was conducted from 2017 to 2020 in Shenzhen,China.In total,51,205 participants were included comprising two models(early pregnancy model and middle pregnancy model).Gestational weight(kg)was measured at each prenatal clinical visit using a standardized weight scale.Logistic regression analysis was used to assess the risk of GDM.Interaction analysis and mediation effect analysis were performed in the middle pregnancy model.Results:In the early pregnancy model,the risk of GDM was 0.858 times lower(95%confidence interval[CI]:0.786,0.937)with insufficient GWG(iGWG)and 1.201 times higher(95%CI:1.097,1.316)with excessive GWG after adjustment.In the middle pregnancy model,the risk of GDM associated with iGWG increased 1.595 times(95%CI:1.418,1.794)after adjustment;for excessive GWG,no significant difference was found(P=0.223).Interaction analysis showed no interaction between GWG in early pregnancy(GWG-E)and GWG in middle pregnancy(GWG-M)(F=1.268;P=0.280).The mediation effect analysis indicated that GWG-M plays a partial mediating role,with an effect proportion of 14.9%.Conclusions:eGWG-E and iGWG-M are associated with an increased risk of GDM.Strict control of weight gain in early pregnancy is needed,and sufficient nutrition should be provided in middle pregnancy.