This study deals with the Permutation Flow Shop Scheduling Problem （PFSP） based on the maximum completion time （makespan）. NEH （ the algorithm of Nawaz, Eascore and Ham） is the concluded most efficient construct...This study deals with the Permutation Flow Shop Scheduling Problem （PFSP） based on the maximum completion time （makespan）. NEH （ the algorithm of Nawaz, Eascore and Ham） is the concluded most efficient constructive method in solving this NP-hard problem. The principal features of its strengths are the initial arrangement of jobs and the job insertion phase. In some instances, ties will occur in both the initial permutation and the partial sequences. The problem of ties breaking may have a significant impact on the NEH performance, but evaluate all the ties will be non-polynomial in the worst case. Several kinds of methods are presented in the paper to break the ties in a quick time. Together with the basic one, all 22 methods are tested on the famous Taillard＇s benchmarks and the most suitable ties breaking policy is recommended.展开更多
This paper presents a fuzzy tuning system for real-time industrial PID （proportional-integral-derivative） controllers. The algorithm set the proportional gain, integral time and derivative time of a classical PID st...This paper presents a fuzzy tuning system for real-time industrial PID （proportional-integral-derivative） controllers. The algorithm set the proportional gain, integral time and derivative time of a classical PID structure according to the set point, error and error derivative of the process, respectively. The tuning of the PID controller is based on a fuzzy inference machine. The set of rules of the fuzzy inference machine was obtained by experts engineering. The system is tested in an austempering process but can be applied in any industrial plant. Besides, an analysis between the response of the process with a PID controller and the system of fuzzy auto-tuning for P1D proposed was made.展开更多
In this paper, the influence of low power factor on electricity system and the influence of paper breaking on heat system are presented. For that, a mathematical model and a case study for a paper mill are realised. T...In this paper, the influence of low power factor on electricity system and the influence of paper breaking on heat system are presented. For that, a mathematical model and a case study for a paper mill are realised. The electric mathematical model is based on the relations of energy losses in cables and in transformers as a function of power factor. The thermal mathematical model includes characteristic energy and efficiency of boiler depending on its load. Characteristic of efficiency is modeled by a quadratic dependence between fuel consumption and steam flow. In the case, study were estimated to reduce energy losses for factor neutral （0.92） against real power factor （0.75） for the electrical scheme of a paper machine. Analytical expression of the boiler characteristic and variation of boiler efficiency depending on its load were estimated, too.展开更多
In order to evaluate the operational reliability of Japanese FBR （fast breeder reactor） MONJU, frequencies of important intermediate events and equipment failures resulting during reactor automatic trip are predicte...In order to evaluate the operational reliability of Japanese FBR （fast breeder reactor） MONJU, frequencies of important intermediate events and equipment failures resulting during reactor automatic trip are predicted using FTA （fault tree analysis） technique for the plant system model. The targeted devices are the following： PHTS （primary heat transport system）, SHTS （secondary heat transport system）, WS （water and steam system）, PPS （plant protection system） and PCS （plant control system）. In this paper, the frequency of automatic reactor trips was estimated by extracting and analyzing the important intermediate events and equipment failures covering all the derived fault trees of these systems. The analyses predicted 1.2/RY （reactor year） the value of unplanned shut down frequency by the internal factor of the system. The largest contributed event was function failure of SHTS accounting for 42.6% of total events followed by PHTS with 40.1%. The contribution factor of WS was only 4.4%.展开更多
基金Programfor New Century Excellent Talents in University,China(NO.NCET04-0383)Science and Technology Phosphor Program of Shanghai,China(NO.04QMH1405)
文摘This study deals with the Permutation Flow Shop Scheduling Problem （PFSP） based on the maximum completion time （makespan）. NEH （ the algorithm of Nawaz, Eascore and Ham） is the concluded most efficient constructive method in solving this NP-hard problem. The principal features of its strengths are the initial arrangement of jobs and the job insertion phase. In some instances, ties will occur in both the initial permutation and the partial sequences. The problem of ties breaking may have a significant impact on the NEH performance, but evaluate all the ties will be non-polynomial in the worst case. Several kinds of methods are presented in the paper to break the ties in a quick time. Together with the basic one, all 22 methods are tested on the famous Taillard＇s benchmarks and the most suitable ties breaking policy is recommended.
文摘This paper presents a fuzzy tuning system for real-time industrial PID （proportional-integral-derivative） controllers. The algorithm set the proportional gain, integral time and derivative time of a classical PID structure according to the set point, error and error derivative of the process, respectively. The tuning of the PID controller is based on a fuzzy inference machine. The set of rules of the fuzzy inference machine was obtained by experts engineering. The system is tested in an austempering process but can be applied in any industrial plant. Besides, an analysis between the response of the process with a PID controller and the system of fuzzy auto-tuning for P1D proposed was made.
文摘In this paper, the influence of low power factor on electricity system and the influence of paper breaking on heat system are presented. For that, a mathematical model and a case study for a paper mill are realised. The electric mathematical model is based on the relations of energy losses in cables and in transformers as a function of power factor. The thermal mathematical model includes characteristic energy and efficiency of boiler depending on its load. Characteristic of efficiency is modeled by a quadratic dependence between fuel consumption and steam flow. In the case, study were estimated to reduce energy losses for factor neutral （0.92） against real power factor （0.75） for the electrical scheme of a paper machine. Analytical expression of the boiler characteristic and variation of boiler efficiency depending on its load were estimated, too.
文摘In order to evaluate the operational reliability of Japanese FBR （fast breeder reactor） MONJU, frequencies of important intermediate events and equipment failures resulting during reactor automatic trip are predicted using FTA （fault tree analysis） technique for the plant system model. The targeted devices are the following： PHTS （primary heat transport system）, SHTS （secondary heat transport system）, WS （water and steam system）, PPS （plant protection system） and PCS （plant control system）. In this paper, the frequency of automatic reactor trips was estimated by extracting and analyzing the important intermediate events and equipment failures covering all the derived fault trees of these systems. The analyses predicted 1.2/RY （reactor year） the value of unplanned shut down frequency by the internal factor of the system. The largest contributed event was function failure of SHTS accounting for 42.6% of total events followed by PHTS with 40.1%. The contribution factor of WS was only 4.4%.
