This paper studied cardinality constrained portfolio with integer weight.We suggested two optimization models and used two genetic algorithms to solve them.In this paper,after finding well matching stocks,according to...This paper studied cardinality constrained portfolio with integer weight.We suggested two optimization models and used two genetic algorithms to solve them.In this paper,after finding well matching stocks,according to investor’s target by using first genetic algorithm,we gave optimal integer weight of portfolio with well matching stocks by using second genetic algorithm.Through numerical comparisons with other feasible portfolios,we verified advantages of designed portfolio with two genetic algorithms.For a numerical comparison,we used a prepared data consisted of 18 stocks listed in S&P 500 and numerical example strongly supported the designed portfolio in this paper.Also,we made all comparisons visible through all feasible efficient frontiers.展开更多
This study investigated the effects of torrefaction on forest residue(FR)and its subsequent ap-plication as a bulk-loading filler in polylactic acid(PLA)composites.Torrefaction enhanced the chemical properties of FR,i...This study investigated the effects of torrefaction on forest residue(FR)and its subsequent ap-plication as a bulk-loading filler in polylactic acid(PLA)composites.Torrefaction enhanced the chemical properties of FR,improving its compatibility with PLA,and the crystallinity increased from 24.9%to 42.5%.The process also improved the hydrophobicity of PLA/biomass composites,as demonstrated by the water contact angle of 76.1°,closely matching that of neat PLA(76.4°).With the introduction of 20%modified biomass properties after torrefaction treatment,the tensile strength of PLA/biomass composite increased from 58.7 to 62.3 MPa.Additionally,the addition of torrefied forest residue(TFR)accelerated biodegradation by increasing the onset of degrada-tion and inhibiting crystallization.After 90 d,the biodegradability of PLA/biomass composites reached 94.9%,which had a 6.9%increase compared to the neat PLA(88.8%).Overall,this study highlights the potential of torrefaction in enhancing both the physical properties and biodegrad-ability of PLA-based composites,contributing to a more sustainable approach to reducing plastic pollution.展开更多
Fast pyrolysis bio-oils(fpBO)were extracted with two alternative commercial transportation fuels,hydrocarbon diesel and bio-diesel.The extraction of fpBO with commercial diesel fuel provided a yield of 4.3 wt%,but the...Fast pyrolysis bio-oils(fpBO)were extracted with two alternative commercial transportation fuels,hydrocarbon diesel and bio-diesel.The extraction of fpBO with commercial diesel fuel provided a yield of 4.3 wt%,but the yield increased significantly to 26.6 wt%when bio-diesel was the extractant.The molecular weight of fpBO before and after extraction were consistent with the loss of a more soluble,low molecular weight fraction from the crude fpBO.The relative energy difference(RED),based on the Hansen solubility parameter(HSP),is used to examine the extraction efficiency of specific compounds in the two different‘solvents’.Differences in the RED values could be used to rationalize differences in the partitioning of common fpBO phenolics.展开更多
文摘This paper studied cardinality constrained portfolio with integer weight.We suggested two optimization models and used two genetic algorithms to solve them.In this paper,after finding well matching stocks,according to investor’s target by using first genetic algorithm,we gave optimal integer weight of portfolio with well matching stocks by using second genetic algorithm.Through numerical comparisons with other feasible portfolios,we verified advantages of designed portfolio with two genetic algorithms.For a numerical comparison,we used a prepared data consisted of 18 stocks listed in S&P 500 and numerical example strongly supported the designed portfolio in this paper.Also,we made all comparisons visible through all feasible efficient frontiers.
基金supported by the Korea Research Institute of Chemical Technology(KRICT)Project(No.KS2442-10)the R&D Program(No.20017973)of the Ministry of Trade,Industry,and Energy(MOTIE/KEIT).
文摘This study investigated the effects of torrefaction on forest residue(FR)and its subsequent ap-plication as a bulk-loading filler in polylactic acid(PLA)composites.Torrefaction enhanced the chemical properties of FR,improving its compatibility with PLA,and the crystallinity increased from 24.9%to 42.5%.The process also improved the hydrophobicity of PLA/biomass composites,as demonstrated by the water contact angle of 76.1°,closely matching that of neat PLA(76.4°).With the introduction of 20%modified biomass properties after torrefaction treatment,the tensile strength of PLA/biomass composite increased from 58.7 to 62.3 MPa.Additionally,the addition of torrefied forest residue(TFR)accelerated biodegradation by increasing the onset of degrada-tion and inhibiting crystallization.After 90 d,the biodegradability of PLA/biomass composites reached 94.9%,which had a 6.9%increase compared to the neat PLA(88.8%).Overall,this study highlights the potential of torrefaction in enhancing both the physical properties and biodegrad-ability of PLA-based composites,contributing to a more sustainable approach to reducing plastic pollution.
基金IBSS project funded by Agriculture and Food Research Initiative Competitive Grant no.2011-68005-30410 from the USDA National Institute of Food and Agriculture.
文摘Fast pyrolysis bio-oils(fpBO)were extracted with two alternative commercial transportation fuels,hydrocarbon diesel and bio-diesel.The extraction of fpBO with commercial diesel fuel provided a yield of 4.3 wt%,but the yield increased significantly to 26.6 wt%when bio-diesel was the extractant.The molecular weight of fpBO before and after extraction were consistent with the loss of a more soluble,low molecular weight fraction from the crude fpBO.The relative energy difference(RED),based on the Hansen solubility parameter(HSP),is used to examine the extraction efficiency of specific compounds in the two different‘solvents’.Differences in the RED values could be used to rationalize differences in the partitioning of common fpBO phenolics.
