Research On Ship Deficiency Attributes And Detention Risk Driven By Port State Control Data

The maritime transportation has always played a prominent role in the field of global logistics as it is economical and environmental-friendly.However,the vast ocean is full of risks,and various maritime accidents happened all the time.Therefore,the continuous improvement of the ship safety is always an important topic in the global maritime industry.Since its inception,Port State Control(PSC)has become more and more influential under the prevalent international maritime safety framework.Its development trend of relevant inspection standards and technical means has also become the focus of the industry.Based on the international maritime laws and regulations,PSC has established a comprehensive,objective and globalized ship safety inspection system.A large amount of data related to ship features as well as the software and hardware deficiencies summarized from the inspections include useful information,which can reflect the actual situation of ship safety.As such,through analysis of PSC data structure and with the proper mining approach to eliminate the redundant information and probe into the risks manifested by the data,it is definite that safety risk factors directly or indirectly connected to the deficiencies can be recognized and then the objective rules of ship safety can be refined to a certain extent,which can then become a reference to lowering the system safety risks.Based on the PSC data,this study conducts an in-depth research on ship deficiency attributes and detention risks.The studies are as follows:(1)In light of deficiency correlation,considering the multi-element coupling risk,association rule method was used to systematically carry out study on correlation of ship deficiencies.Given the features of PSC data structure,the optimized Data Quality Control Apriori(DQC-Apriori)algorithm model is adopted to analyze correlation among 18 deficiencies categories,568 deficiencies sub-categories and 277 detainable deficiencies categories.Results showed that: in deficiency categories,frequent itemset has the highest Support and Confidence that 01(Certificates and Documentation)deficiency is to be found when 10(Safety Navigation)deficiency is confirmed;and in deficiency sub-categories,frequent itemset has the highest Support and Confidence that 01220(SEA)deficiency is to be found when 10111(Charts)deficiency is confirmed;while in detainable deficiency categories,frequent itemset has the highest Support and Confidence that 15105(Resources and Personnel)deficiency is to be found when 15106(Shipboard Operations)deficiency is confirmed.The association rule concluded progressively revealed the coupling relationship of different elements,especial y the rules between deficiencies sub-categories and detainable deficiencies which is a relatively good and practical guidance for the ship to identify specific pitfalls.(2)In view of deficiency importance,taking ship detention as the system target risk,the deficiency importance theory containing the element importance,overall importance and integrated importance was proposed.Based on the deficiency element importance,a judgment matrix via PSC Deficiency Hierarchy Structure Model(DEFHSM)was established to obtain the ranking of overall importance weight of deficiencies.It turned out that Certificates and Documentation,Fire Safety,and ISM are the top 3 deficiency categories leading to the ship detention while Endorsement by Flag State,Fire-dampers,Ship and Equipment Maintenance as well as Resources and Personnel are the top 4 deficiency sub-categories leading to ship detention.Based on correlation among different detainable deficiencies,coupling correction variable was introduced to calculate the deficiencies integrated importance weight.And the results showed that Endorsement by Flag State,Fire Detection and Alarm System,and Lifeboat are the top 3 deficiencies sub-categories leading to ship detention.The deficiency integrated importance included the influence of different deficiencies attributes and hence completed correlation correction to overall importance weight,which is positive for revealing influence rules of deficiency importance to ship detention.(3)From the point of ship detention risk,based on the study on deficiency correlation and importance,Detention Risk Anticipation Model(DETRAM)covering detention risk identification,analysis and evaluation etc.was built.Multinomial Naive Bayes(MNB)and Support Vector Machines(SVM)were used in analyzing typical cases based on different deficiency importance weight to reveal change rules of key evaluation indicators.The results proved that compared to the MNB,the value of evaluation indicator calculated via SVM was better;the case without consideration of deficiency importance has the lowest average accuracy;the case taking consideration of overall importance with top 20 detainable deficiencies as input variables had a highest average accuracy while one considering integrated importance with top 15 detainable deficiencies as input variables had a highest average accuracy.In view of the analysis conclusion,to better synthesize the deficiency correlation and importance,it was confirmed to take top 15 detainable deficiencies ranked by integrated importance as input variables through SVM for applications in order to help management company to have targeted risk-proof check based on the anticipated ship detention rate.Given all above,the study on deficiency correlation,deficiency importance and detention risk anticipation are a theoretical breakthrough and of practical instruction significance to a certain extent.Relying on objective data analysis,it can dilute the influence of subjective factor to decision making,and thus promoting the quantitative management of ship safety and prevention of system risk.