Various traffic management strategies have been developed to alleviate the congestion on freeways. The equity issue has been considered as one of the major challenges for the implementation of some traffic control str...Various traffic management strategies have been developed to alleviate the congestion on freeways. The equity issue has been considered as one of the major challenges for the implementation of some traffic control strategies, especially ramp metering. This paper presents a comparative evaluation of the efficiency and equity performance of a traffic control strategies namely Fixed Time Ramp Metering (FTRM). Instead of focusing on a single equity measure and/or indicator, different approaches to the equity concept are discussed and various equity measures are examined. The equity and efficiency performance of traffic control strategies are compared and evaluated by incorporating them into the simulated corridor. The Bosporus Bridge of Istanbul O-1 Freeway, Turkey is used as a test-bed for the simulation model and the control strategy is employed through microscopic traffic flow simulation software, VISSIM AG. The findings from the simulations show that the equity and efficiency properties of the network vary with the measures and indicators taken into account. The results also suggest that the trade-off between equity and efficiency can be observed for some measures, whereas regarding to other measures the trade-off is not validated.展开更多
Scientific Land Reform is at centre of decades＇ conflict and even during Peace Process in Nepal. In this regards, land reform attempts to address equity and efficiency so as to address historical inequity and injusti...Scientific Land Reform is at centre of decades＇ conflict and even during Peace Process in Nepal. In this regards, land reform attempts to address equity and efficiency so as to address historical inequity and injustices for promoting peace process in Nepal. From equity perspective, landlessness, unequal power structure and social relation, injustices and discrimination for long centuries are key land issues. Along with this, economic efficiency is the fundamental for enhancing agricultural growth leading to economic growth. In particular, this article argues that, in the given prevailing condition, i.e. traditional and subsistence and rampant rural poverty and unequal power structure and injustices, small farms perform better leading to food and livelihood security at household level. Consequently, ＇Scientific Land Reform＇ has been defined by taking into account the essence of equity and efficiency.展开更多
This paper presents results concerning energy efficiency of wheat production considered in the context of specific energy input variation in different climatic conditions of Europe as well as case studies on implement...This paper presents results concerning energy efficiency of wheat production considered in the context of specific energy input variation in different climatic conditions of Europe as well as case studies on implementation of selected energy saving measures in practice. The source data collected from the six european union （EU） countries represent five agricultural regions of continental Europe and three climates： continental, temperate and Mediterranean. The life cycle assessment （LCA） methodology was applied to analyze the data excluding of pre-farm gate activities. The total primary energy consumption was decomposed into main energy input streams and it was regressed to yield. In order to compare energy efficiency of wheat production across the geographical areas, the data envelopment analysis （DEA） was applied. It was shown that the highest wheat yield （6.7 t/ha to 8.7 t/ha） at the lowest specific energy input （2.08 GJ/t to 2.56 G J/t） is unique for temperate climate conditions. The yield in continental and Mediterranean climatic conditions is on average lower by 1.3 t/ha and 2.7 t/ha and energy efficiency lower by 14% and 38%, respectively. The case studies have shown that the energy saving activities in wheat production may be universal for the climatic zones or specific for a given geographical location. It was stated that trade-offs between energy, economic, and environmental effects, which are associated with implementation of a given energy saving measure or a set of measures to a great extent depend on the current energy efficiency status of the farm and opportunity for investment, which varies substantially across Europe.展开更多
Motivated by the objective of pursuing revenue, improvement in coverage and reduction in energy cost for wireless communication networks have been of great significance for mobile operators. Therefore, heterogeneous c...Motivated by the objective of pursuing revenue, improvement in coverage and reduction in energy cost for wireless communication networks have been of great significance for mobile operators. Therefore, heterogeneous cellular networks(HCNs) and Coordinated Multipoint(Co MP) transmission are considered as promising solutions to enhance the performances of wireless communication systems. This paper analyzed the K-tier HCNs with a dynamic downlink Co MP scheme, in which the flexible clusters of cooperative stations are determined by a connecting threshold θ. Using stochastic geometry, the coverage probability(CP) and energy efficiency(EE) of a K-tier HCN operating under this scheme are derived, based on which the trade-off between CP and EE is discovered and discussed. Simulation results show the validity of our derivations. The proposed schememay significantly reduce energy consumption sacrificing a small amount of CP, and outperforms the fixed scheme as well. The CP-EE trade-off are also revealed, whichsuggests suitable trade-off points between CP and EE that will deliver the maximum economic profitability. Tendencies discovered in this paper may provide the operators with opportunities for further optimization in pursuit of economic profitability.展开更多
文摘Various traffic management strategies have been developed to alleviate the congestion on freeways. The equity issue has been considered as one of the major challenges for the implementation of some traffic control strategies, especially ramp metering. This paper presents a comparative evaluation of the efficiency and equity performance of a traffic control strategies namely Fixed Time Ramp Metering (FTRM). Instead of focusing on a single equity measure and/or indicator, different approaches to the equity concept are discussed and various equity measures are examined. The equity and efficiency performance of traffic control strategies are compared and evaluated by incorporating them into the simulated corridor. The Bosporus Bridge of Istanbul O-1 Freeway, Turkey is used as a test-bed for the simulation model and the control strategy is employed through microscopic traffic flow simulation software, VISSIM AG. The findings from the simulations show that the equity and efficiency properties of the network vary with the measures and indicators taken into account. The results also suggest that the trade-off between equity and efficiency can be observed for some measures, whereas regarding to other measures the trade-off is not validated.
文摘Scientific Land Reform is at centre of decades＇ conflict and even during Peace Process in Nepal. In this regards, land reform attempts to address equity and efficiency so as to address historical inequity and injustices for promoting peace process in Nepal. From equity perspective, landlessness, unequal power structure and social relation, injustices and discrimination for long centuries are key land issues. Along with this, economic efficiency is the fundamental for enhancing agricultural growth leading to economic growth. In particular, this article argues that, in the given prevailing condition, i.e. traditional and subsistence and rampant rural poverty and unequal power structure and injustices, small farms perform better leading to food and livelihood security at household level. Consequently, ＇Scientific Land Reform＇ has been defined by taking into account the essence of equity and efficiency.
文摘This paper presents results concerning energy efficiency of wheat production considered in the context of specific energy input variation in different climatic conditions of Europe as well as case studies on implementation of selected energy saving measures in practice. The source data collected from the six european union （EU） countries represent five agricultural regions of continental Europe and three climates： continental, temperate and Mediterranean. The life cycle assessment （LCA） methodology was applied to analyze the data excluding of pre-farm gate activities. The total primary energy consumption was decomposed into main energy input streams and it was regressed to yield. In order to compare energy efficiency of wheat production across the geographical areas, the data envelopment analysis （DEA） was applied. It was shown that the highest wheat yield （6.7 t/ha to 8.7 t/ha） at the lowest specific energy input （2.08 GJ/t to 2.56 G J/t） is unique for temperate climate conditions. The yield in continental and Mediterranean climatic conditions is on average lower by 1.3 t/ha and 2.7 t/ha and energy efficiency lower by 14% and 38%, respectively. The case studies have shown that the energy saving activities in wheat production may be universal for the climatic zones or specific for a given geographical location. It was stated that trade-offs between energy, economic, and environmental effects, which are associated with implementation of a given energy saving measure or a set of measures to a great extent depend on the current energy efficiency status of the farm and opportunity for investment, which varies substantially across Europe.
基金supported by the National Natural Science Foundation of China under Grant No.61231009the National High-tech Research and Development Program of China under Grant No.2014AA01A701the Program for New Century Excellent Talents in University of Ministry of Education of China under Grant No.NCET 12-0795
文摘Motivated by the objective of pursuing revenue, improvement in coverage and reduction in energy cost for wireless communication networks have been of great significance for mobile operators. Therefore, heterogeneous cellular networks(HCNs) and Coordinated Multipoint(Co MP) transmission are considered as promising solutions to enhance the performances of wireless communication systems. This paper analyzed the K-tier HCNs with a dynamic downlink Co MP scheme, in which the flexible clusters of cooperative stations are determined by a connecting threshold θ. Using stochastic geometry, the coverage probability(CP) and energy efficiency(EE) of a K-tier HCN operating under this scheme are derived, based on which the trade-off between CP and EE is discovered and discussed. Simulation results show the validity of our derivations. The proposed schememay significantly reduce energy consumption sacrificing a small amount of CP, and outperforms the fixed scheme as well. The CP-EE trade-off are also revealed, whichsuggests suitable trade-off points between CP and EE that will deliver the maximum economic profitability. Tendencies discovered in this paper may provide the operators with opportunities for further optimization in pursuit of economic profitability.
