Research On Scheduling Optimization For Seafarers’ Physical Examination

According to the National Bureau of Statistics,China’s total import and export of goods trade in 2022 was 42.07 trillion yuan,an increase of 7.7% year-on-year.Port container throughput also reached 295.87 million TEUs,an increase of 4.7% year-on-year.Meanwhile,by the end of 2021,China has become the country with the largest number of seafarers in the world,with 570,000 seafarers registered for international voyages alone.Due to the special nature of the marine operating environment,fuel oil(lubricating oil),noise,humidity,vibration,high temperature,drinking water pollution,etc.are very likely to cause occupational diseases of seafarers and lead to various accidents.Therefore,how to reduce the risk caused by health problems of seafarers and avoid the resulting loss of life and property has become one of the urgent problems in China’s maritime industry.As one of the means to effectively reduce the health risk of seafarers,the cost control and efficiency improvement of seafarer medical examination process has attracted much scholarly attention.Considering that the standard,process and urgency of seafarer medical examination are different from traditional health examination,the actual seafarer medical examination is more in a short-term centralized form.Therefore the pressure on the fixed inspection agency is very high at a given time.For reasons of time,economic cost and the impact of customer satisfaction on the institution,etc.,medical examination institutions can adopt two models of distributed medical examination and refusable acceptance to relieve the pressure of medical examination.In this thesis,two scheduling optimization problems are refined based on these two medical examination patterns and combining them with the actual problem context.The main research is as follows:(1)Rejectable medical examination scheduling problem considering seafarer arrival time: The medical examination organization has to reject the medical examination application of some seafarers who arrive in real time and reassign them to other medical examination organizations or make another appointment for medical examination due to the maximum acceptance capacity,equipment capacity and other factors.While introducing the concept of rejection cost,the sum of the maximum completion time of all seafarers’ medical examinations and the rejection cost is chosen as the optimization target.(2)Distributed medical examination scheduling problem considering the arrival time of seafarers.When there are more than one medical examination institutions in a certain area,seafarers can be arranged to go to different institutions for medical examination according to the busy degree of different medical examination institutions.At this time,the seafarer medical examination scheduling problem can be regarded as a distributed medical examination scheduling problem considering the arrival time of seafarers,and the optimization objective is to minimize the sum of squares of the seafarer medical examination completion time.For these two strong NP-hard problems,firstly,a mixed-integer programming model is developed for each of them and the exact solution is found using CPLEX software.Secondly,intelligent optimization algorithms are designed and improvement strategies are proposed with the problem characteristics.Finally,through the analysis of the optimal solution structure,large-scale heuristic algorithms based on the dense idea are proposed for each of the two problems,and their asymptotic optimality is verified by the experimental results.The numerical experimental results are analyzed and generalized to obtain that the heuristic and improvement strategies based on the dense idea have certain guiding meaning and application value for real seafarer medical examination scenarios.