With the increase of problem dimensions,most solutions of existing many-objective optimization algorithms are non-dominant.Therefore,the selection of individuals and the retention of elite individuals are important.Ex...With the increase of problem dimensions,most solutions of existing many-objective optimization algorithms are non-dominant.Therefore,the selection of individuals and the retention of elite individuals are important.Existing algorithms cannot provide sufficient solution precision and guarantee the diversity and convergence of solution sets when solving practical many-objective industrial problems.Thus,this work proposes an improved many-objective pigeon-inspired optimization(ImMAPIO)algorithm with multiple selection strategies to solve many-objective optimization problems.Multiple selection strategies integrating hypervolume,knee point,and vector angles are utilized to increase selection pressure to the true Pareto Front.Thus,the accuracy,convergence,and diversity of solutions are improved.ImMAPIO is applied to the DTLZ and WFG test functions with four to fifteen objectives and compared against NSGA-III,GrEA,MOEA/D,RVEA,and many-objective Pigeon-inspired optimization algorithm.Experimental results indicate the superiority of ImMAPIO on these test functions.展开更多
This paper brings forward a novel dynamic multiple access network selection scheme(NDMAS),which could achieve less energy loss and improve the poor adaptive capability caused by the variable network parameters.Firstly...This paper brings forward a novel dynamic multiple access network selection scheme(NDMAS),which could achieve less energy loss and improve the poor adaptive capability caused by the variable network parameters.Firstly,a multiple access network selection mathematical model based on information theory is presented.From the perspective of information theory,access selection is essentially a process to reduce the information entropy in the system.It can be found that the lower the information entropy is,the better the system performance fulfills.Therefore,this model is designed to reduce the information entropy by removing redundant parameters,and to avoid the computational cost as well.Secondly,for model implementation,the Principal Component Analysis(PCA) is employed to process the observation data to find out the related factors which affect the users most.As a result,the information entropy is decreased.Theoretical analysis proves that system loss and computational complexity have been decreased by using the proposed approach,while the network QoS and accuracy are guaranteed.Finally,simulation results show that our scheme achieves much better system performance in terms of packet delay,throughput and call blocking probability than other currently existing ones.展开更多
Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the fac...Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the factors affecting mining method selection are determined. These factors include shape, thick- ness, depth, slope, RMR and RSS of the orebody, RMR and RSS of the hanging wall and footwall. Then, the priorities of these factors are calculated. In order to calculate the priorities of factors and select the best mining method for Qapiliq salt mine, Iran, based on these priorities, fuzzy analytical hierarchy process （AHP） technique is used. For this purpose, a questionnaire was prepared and was given to the associated experts. Finally, after a comparison carried out based on the effective factors, between the four mining methods including area mining, room and pillar, cut and fill and stope and pillar methods, the stope and nillar mining method was selected as the most suitable method to this mine.展开更多
Selective catalytic transfer hydrogenation(CTH)of carbonyl compounds to obtain specific alcohols holds significant importance across various fields.Achieving multiple selectivity in CTH is particularly crucial,but ful...Selective catalytic transfer hydrogenation(CTH)of carbonyl compounds to obtain specific alcohols holds significant importance across various fields.Achieving multiple selectivity in CTH is particularly crucial,but full of great challenge.Herein,a cationic In-captured Zr-porphyrin framework(1)with nanosized pores/cages was successfully constructed and showed high structure stability.Catalytic investigations revealed that 1 displayed highly multi-selective CTH of aldehydes and ketones containing both chemo-and size selectivity for the first time.The CTH of aldehydes and ketones exhibited remarkable reductive selectivity of 99%towards C=O bonds into CH–OH in the presence of-NO_(2),-CN and C=C groups.Through tuning the reaction conditions,1 also exhibited highly selective reduction of 97%for-CHO groups in the simultaneous presence of-CHO and-COCH3groups in intra-and intermolecular settings.Remarkably,reductive selectivity towards-CHO group remained prominent among five concurrent unsaturated groups mentioned above.Additionally,the definite pore size of 1 facilitated volume control of substrates,enabling size selectivity.1 as a heterogeneous catalyst was further confirmed by leaching tests,and maintained high activity even after being used for at least six cycles.Mechanistic studies have revealed that Zr6O8clusters served as the catalytic centers and the observed chemoselectivity mainly results from the synergistic effect of distinct metal sites within 1.The heightened selectivity towards-CHO over-COCH_(3)can be attributed to the easier realization of transfer hydrogenation processes for-CHO compared to-COCH_(3).展开更多
In order to meet the needs of high-speed development of optical communication system, a construction method of quasi-cyclic low-density parity-check(QC-LDPC) codes based on multiplicative group of finite field is prop...In order to meet the needs of high-speed development of optical communication system, a construction method of quasi-cyclic low-density parity-check(QC-LDPC) codes based on multiplicative group of finite field is proposed. The Tanner graph of parity check matrix of the code constructed by this method has no cycle of length 4, and it can make sure that the obtained code can get a good distance property. Simulation results show that when the bit error rate(BER) is 10-6, in the same simulation environment, the net coding gain(NCG) of the proposed QC-LDPC(3 780, 3 540) code with the code rate of 93.7% in this paper is improved by 2.18 dB and 1.6 dB respectively compared with those of the RS(255, 239) code in ITU-T G.975 and the LDPC(3 2640, 3 0592) code in ITU-T G.975.1. In addition, the NCG of the proposed QC-LDPC(3 780, 3 540) code is respectively 0.2 dB and 0.4 dB higher compared with those of the SG-QC-LDPC(3 780, 3 540) code based on the two different subgroups in finite field and the AS-QC-LDPC(3 780, 3 540) code based on the two arbitrary sets of a finite field. Thus, the proposed QC-LDPC(3 780, 3 540) code in this paper can be well applied in optical communication systems.展开更多
基金This work was supported by the National Key Research and Development Program of China(No.2018YFC1604000)the National Natural Science Foundation of China(Nos.61806138,61772478,U1636220,61961160707,and 61976212)+2 种基金the Key R&D Program of Shanxi Province(High Technology)(No.201903D121119)the Key R&D Program of Shanxi Province(International Cooperation)(No.201903D421048)the Key R&D Program(International Science and Technology Cooperation Project)of Shanxi Province,China(No.201903D421003).
文摘With the increase of problem dimensions,most solutions of existing many-objective optimization algorithms are non-dominant.Therefore,the selection of individuals and the retention of elite individuals are important.Existing algorithms cannot provide sufficient solution precision and guarantee the diversity and convergence of solution sets when solving practical many-objective industrial problems.Thus,this work proposes an improved many-objective pigeon-inspired optimization(ImMAPIO)algorithm with multiple selection strategies to solve many-objective optimization problems.Multiple selection strategies integrating hypervolume,knee point,and vector angles are utilized to increase selection pressure to the true Pareto Front.Thus,the accuracy,convergence,and diversity of solutions are improved.ImMAPIO is applied to the DTLZ and WFG test functions with four to fifteen objectives and compared against NSGA-III,GrEA,MOEA/D,RVEA,and many-objective Pigeon-inspired optimization algorithm.Experimental results indicate the superiority of ImMAPIO on these test functions.
基金supported by National Natural Science Foundation of China under Grant No.60971083National International Science and Technology Cooperation Project of China (No.2010DFA11320)
文摘This paper brings forward a novel dynamic multiple access network selection scheme(NDMAS),which could achieve less energy loss and improve the poor adaptive capability caused by the variable network parameters.Firstly,a multiple access network selection mathematical model based on information theory is presented.From the perspective of information theory,access selection is essentially a process to reduce the information entropy in the system.It can be found that the lower the information entropy is,the better the system performance fulfills.Therefore,this model is designed to reduce the information entropy by removing redundant parameters,and to avoid the computational cost as well.Secondly,for model implementation,the Principal Component Analysis(PCA) is employed to process the observation data to find out the related factors which affect the users most.As a result,the information entropy is decreased.Theoretical analysis proves that system loss and computational complexity have been decreased by using the proposed approach,while the network QoS and accuracy are guaranteed.Finally,simulation results show that our scheme achieves much better system performance in terms of packet delay,throughput and call blocking probability than other currently existing ones.
文摘Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the factors affecting mining method selection are determined. These factors include shape, thick- ness, depth, slope, RMR and RSS of the orebody, RMR and RSS of the hanging wall and footwall. Then, the priorities of these factors are calculated. In order to calculate the priorities of factors and select the best mining method for Qapiliq salt mine, Iran, based on these priorities, fuzzy analytical hierarchy process （AHP） technique is used. For this purpose, a questionnaire was prepared and was given to the associated experts. Finally, after a comparison carried out based on the effective factors, between the four mining methods including area mining, room and pillar, cut and fill and stope and pillar methods, the stope and nillar mining method was selected as the most suitable method to this mine.
基金supported by National Nature Science Foundation of China(Nos.92161202 and 22121005)China Postdoctoral Science Foundation(Nos.2023M741814 and 2023M741815)+2 种基金Postdoctoral Fellowship Program of CPSF(No.GZC20231170)Natural Science Foundation of Science&Technology Department of Sichuan Province(No.2023NSFSC110)Research and Innovation Team of China West Normal University(No.KCXTD2023-1)。
文摘Selective catalytic transfer hydrogenation(CTH)of carbonyl compounds to obtain specific alcohols holds significant importance across various fields.Achieving multiple selectivity in CTH is particularly crucial,but full of great challenge.Herein,a cationic In-captured Zr-porphyrin framework(1)with nanosized pores/cages was successfully constructed and showed high structure stability.Catalytic investigations revealed that 1 displayed highly multi-selective CTH of aldehydes and ketones containing both chemo-and size selectivity for the first time.The CTH of aldehydes and ketones exhibited remarkable reductive selectivity of 99%towards C=O bonds into CH–OH in the presence of-NO_(2),-CN and C=C groups.Through tuning the reaction conditions,1 also exhibited highly selective reduction of 97%for-CHO groups in the simultaneous presence of-CHO and-COCH3groups in intra-and intermolecular settings.Remarkably,reductive selectivity towards-CHO group remained prominent among five concurrent unsaturated groups mentioned above.Additionally,the definite pore size of 1 facilitated volume control of substrates,enabling size selectivity.1 as a heterogeneous catalyst was further confirmed by leaching tests,and maintained high activity even after being used for at least six cycles.Mechanistic studies have revealed that Zr6O8clusters served as the catalytic centers and the observed chemoselectivity mainly results from the synergistic effect of distinct metal sites within 1.The heightened selectivity towards-CHO over-COCH_(3)can be attributed to the easier realization of transfer hydrogenation processes for-CHO compared to-COCH_(3).
基金supported by the National Natural Science Foundation of China(No.61571072)the Basic and Advanced Technology Research Project in Chongqing(No.cstc2015jcyjA 40015)
文摘In order to meet the needs of high-speed development of optical communication system, a construction method of quasi-cyclic low-density parity-check(QC-LDPC) codes based on multiplicative group of finite field is proposed. The Tanner graph of parity check matrix of the code constructed by this method has no cycle of length 4, and it can make sure that the obtained code can get a good distance property. Simulation results show that when the bit error rate(BER) is 10-6, in the same simulation environment, the net coding gain(NCG) of the proposed QC-LDPC(3 780, 3 540) code with the code rate of 93.7% in this paper is improved by 2.18 dB and 1.6 dB respectively compared with those of the RS(255, 239) code in ITU-T G.975 and the LDPC(3 2640, 3 0592) code in ITU-T G.975.1. In addition, the NCG of the proposed QC-LDPC(3 780, 3 540) code is respectively 0.2 dB and 0.4 dB higher compared with those of the SG-QC-LDPC(3 780, 3 540) code based on the two different subgroups in finite field and the AS-QC-LDPC(3 780, 3 540) code based on the two arbitrary sets of a finite field. Thus, the proposed QC-LDPC(3 780, 3 540) code in this paper can be well applied in optical communication systems.
