Extraction and analysis of the shoreline and land reclamation patterns are important for studies on topics such as the dynamics of coastal wetland ecological environments,transportation and exchange of material energy...Extraction and analysis of the shoreline and land reclamation patterns are important for studies on topics such as the dynamics of coastal wetland ecological environments,transportation and exchange of material energy in coastal regions,and recruitment of fishery resources.Spatial-temporal variations in the shoreline and land reclamation in the Bohai Sea were analyzed based on 49 Landsat images of 7 periods from 1985 to 2015.The following conclusions were drawn.(1)The extracted shoreline data based on visual interpretation had high precision,and the shoreline extraction errors could be controlled within the theoretical range.(2)Over the past 30 years,the shoreline of the Bohai Sea has exhibited an average rate of change of 188.47 m/a and an average accretion distance of 3.55×10^3 m toward the sea.The fastest rate of shoreline change occurred in Laizhou Bay(134.78 m/a),followed by Bohai Bay(128.20 m/a)and Liaodong Bay(61.69 m/a).(3)The average rate of reclamation was 3.25×10^4 ha/a in the Bohai Sea,where the total area of aquaculture land,unused land,and salt land exceeded 60%of the total reclamation area.(4)The geometric shape of the bay became increasingly complicated from year to year,and the geometric center of gravity of the bay moved rapidly toward the sea.In addition,the area of the bay showed a significant decreasing trend.Therefore,to protect the function and structure of the ecosystem in coastal regions,we must control the scale and rate of land reclamation in the future.展开更多
Along with the rapid development of economics and enhancement of industrialization, the power demand keeps rising and frequently creates mismatch between demand and supply in electricity.This provides miscellaneous en...Along with the rapid development of economics and enhancement of industrialization, the power demand keeps rising and frequently creates mismatch between demand and supply in electricity.This provides miscellaneous energy buy-back programs with great opportunities. Such programs, when activated, offer certain amount of financial compensations to participants for reducing their energy consumption during peak time. They aim at encouraging participants to shift their electricity usage from peak to non-peak time, and thereby release the demand pressure during peak time. This paper considers a periodic-review joint pricing and inventory decision model under an energy buy-back program over finite planning horizons, in which the compensation levels, setup cost and additive random demand function are incorporated. The objective is to maximize a manufacturer's expected total profit.By using Veinott's conditions, it is shown that the manufacturer's optimal decision is a state dependent(s, S, P) policy under a peak market condition, or partly an(s, S, A, P) policy under the normal market condition.展开更多
基金The National Basic Research Program(973 Program)of China,No.2015CB453303The Aoshan Scientific and Technical Innovation Program,No.2015ASKJ02-05+3 种基金The Special Fund of the Taishan Scholar Projectthe “Aoshan Talent” ProjectLaboratory for Marine Fisheries Science and Food Production ProcessesPilot National Laboratory for Marine Science and Technology(Qingdao),No.2017ASTCP-ES07
文摘Extraction and analysis of the shoreline and land reclamation patterns are important for studies on topics such as the dynamics of coastal wetland ecological environments,transportation and exchange of material energy in coastal regions,and recruitment of fishery resources.Spatial-temporal variations in the shoreline and land reclamation in the Bohai Sea were analyzed based on 49 Landsat images of 7 periods from 1985 to 2015.The following conclusions were drawn.(1)The extracted shoreline data based on visual interpretation had high precision,and the shoreline extraction errors could be controlled within the theoretical range.(2)Over the past 30 years,the shoreline of the Bohai Sea has exhibited an average rate of change of 188.47 m/a and an average accretion distance of 3.55×10^3 m toward the sea.The fastest rate of shoreline change occurred in Laizhou Bay(134.78 m/a),followed by Bohai Bay(128.20 m/a)and Liaodong Bay(61.69 m/a).(3)The average rate of reclamation was 3.25×10^4 ha/a in the Bohai Sea,where the total area of aquaculture land,unused land,and salt land exceeded 60%of the total reclamation area.(4)The geometric shape of the bay became increasingly complicated from year to year,and the geometric center of gravity of the bay moved rapidly toward the sea.In addition,the area of the bay showed a significant decreasing trend.Therefore,to protect the function and structure of the ecosystem in coastal regions,we must control the scale and rate of land reclamation in the future.
基金partially supported by Young Faculty Research Fund of Beijing Foreign Studies University(2015JT005)YETP(YETP0851)+3 种基金the National Natural Science Foundation of China(71371032)Key Project of Beijing Foreign Studies University Research Programs(2011XG003)the Humanities and Social Science Research Project of Ministry of Education(13YJA630125)the Fundamental Research Funds for the Central Universities
文摘Along with the rapid development of economics and enhancement of industrialization, the power demand keeps rising and frequently creates mismatch between demand and supply in electricity.This provides miscellaneous energy buy-back programs with great opportunities. Such programs, when activated, offer certain amount of financial compensations to participants for reducing their energy consumption during peak time. They aim at encouraging participants to shift their electricity usage from peak to non-peak time, and thereby release the demand pressure during peak time. This paper considers a periodic-review joint pricing and inventory decision model under an energy buy-back program over finite planning horizons, in which the compensation levels, setup cost and additive random demand function are incorporated. The objective is to maximize a manufacturer's expected total profit.By using Veinott's conditions, it is shown that the manufacturer's optimal decision is a state dependent(s, S, P) policy under a peak market condition, or partly an(s, S, A, P) policy under the normal market condition.
