Intensive land use( ILU) policies affect the demand and supply of land. These policies promote efficient land use, and demands for land must therefore be evaluated in terms of the level of land-use intensity. If the d...Intensive land use( ILU) policies affect the demand and supply of land. These policies promote efficient land use, and demands for land must therefore be evaluated in terms of the level of land-use intensity. If the demand is considered excessive, ILU policies act like a "valve"to restrict the land supply. Drawing on data from Chengdu,China,where developable land is scarce,we construct a model using system dynamics( SD) to simulate two scenarios: ILU development and non-ILU development. The results show that when ILU leads to positive land-use efficiency,land supply will exceed demand,resulting in an appropriate level of real demand for the current population level and GDP. Thus,artificial demand( inflated by investors) is reduced. By contrast,when non-ILU leads to negative land-use efficiency,land demand will exceed supply. In this scenario,artificial demand is higher than real demand.展开更多
Mathematics is a key factor in achieving the Sustainable Development Goals (SDGs), because of its applicability to real situations. To achieve the set goals in SDG, this paper suggests some mathematical methods that w...Mathematics is a key factor in achieving the Sustainable Development Goals (SDGs), because of its applicability to real situations. To achieve the set goals in SDG, this paper suggests some mathematical methods that will be useful for solving real situations in relation to goals 2 and 12 of SDGs approved by UN when modeled mathematically. The Northwest Corner Method (NWCM), Least Cost Method (LCM), and Vogel Approximation Method (VAM), which are the initial solution methods were examined to ascertain the ideal route of transporting commodities from production facilities to requirement destination while the optimal solution methods involve Stepping Stone Method (SSM), and Modified Distribution Method (MDM), that give the feasible solution which will enhance minimum transportation cost were also thoroughly defined. Subsequent research shall focus on application of the methods in relation to SDGs problems in comparison with other existing methods.展开更多
The growth of renewable energy has accelerated globally toward a low-carbon economy since the Paris Agreement entered into force in 2016.As a result of the increase of variable renewable energy(VRE),namely solar PV an...The growth of renewable energy has accelerated globally toward a low-carbon economy since the Paris Agreement entered into force in 2016.As a result of the increase of variable renewable energy(VRE),namely solar PV and wind,power systems require more flexibility from conventional power plants with less power generation to regulate increased variability.There are sources of flexibility other than conventional power plants,including enhanced power networks,storage capacity and demand response.To maximize economic utilization of VRE power generation,it is necessary to use the flexibility potential from all these sources.In Japan,the share of VRE has increased since the introduction of a feed-in tariff(FIT)and,in parallel,power market reform is underway.Japan has a unique power system of nine grids connected like a fish bone,making the uptake of an increasing share of VRE challenging.This paper assesses the value of flexibility by source in Japan’s power system in 2030.An analysis of different VRE scenarios is undertaken based on a newly developed production cost model.The result of the simulation shows the quantitative impact of each source of flexibility to the generation cost and VRE curtailment and demonstrates the mechanism by which flexibility works to impact VRE curtailment.展开更多
基金Hundred-Talent Program of Ministry of Land and Resources,China
文摘Intensive land use( ILU) policies affect the demand and supply of land. These policies promote efficient land use, and demands for land must therefore be evaluated in terms of the level of land-use intensity. If the demand is considered excessive, ILU policies act like a "valve"to restrict the land supply. Drawing on data from Chengdu,China,where developable land is scarce,we construct a model using system dynamics( SD) to simulate two scenarios: ILU development and non-ILU development. The results show that when ILU leads to positive land-use efficiency,land supply will exceed demand,resulting in an appropriate level of real demand for the current population level and GDP. Thus,artificial demand( inflated by investors) is reduced. By contrast,when non-ILU leads to negative land-use efficiency,land demand will exceed supply. In this scenario,artificial demand is higher than real demand.
文摘Mathematics is a key factor in achieving the Sustainable Development Goals (SDGs), because of its applicability to real situations. To achieve the set goals in SDG, this paper suggests some mathematical methods that will be useful for solving real situations in relation to goals 2 and 12 of SDGs approved by UN when modeled mathematically. The Northwest Corner Method (NWCM), Least Cost Method (LCM), and Vogel Approximation Method (VAM), which are the initial solution methods were examined to ascertain the ideal route of transporting commodities from production facilities to requirement destination while the optimal solution methods involve Stepping Stone Method (SSM), and Modified Distribution Method (MDM), that give the feasible solution which will enhance minimum transportation cost were also thoroughly defined. Subsequent research shall focus on application of the methods in relation to SDGs problems in comparison with other existing methods.
文摘The growth of renewable energy has accelerated globally toward a low-carbon economy since the Paris Agreement entered into force in 2016.As a result of the increase of variable renewable energy(VRE),namely solar PV and wind,power systems require more flexibility from conventional power plants with less power generation to regulate increased variability.There are sources of flexibility other than conventional power plants,including enhanced power networks,storage capacity and demand response.To maximize economic utilization of VRE power generation,it is necessary to use the flexibility potential from all these sources.In Japan,the share of VRE has increased since the introduction of a feed-in tariff(FIT)and,in parallel,power market reform is underway.Japan has a unique power system of nine grids connected like a fish bone,making the uptake of an increasing share of VRE challenging.This paper assesses the value of flexibility by source in Japan’s power system in 2030.An analysis of different VRE scenarios is undertaken based on a newly developed production cost model.The result of the simulation shows the quantitative impact of each source of flexibility to the generation cost and VRE curtailment and demonstrates the mechanism by which flexibility works to impact VRE curtailment.
