The market-based incentive mechanism of payments for forest environmental services (PFES) seeks to capture part of the benefits derived from forest environmental services and channels them to forest resource owners/ma...The market-based incentive mechanism of payments for forest environmental services (PFES) seeks to capture part of the benefits derived from forest environmental services and channels them to forest resource owners/managers who generate these services, thus increases their incentives to conserve and manage forest resources. This paper examines some of the most important ethical issues entailed by PFES mechanism. The analysis shows that PFES may not always benefit the poor due to the comparative disadvantages of the poor and the complicated characteristics of forest ecosystem services. It is important and urgent to take ethical dimensions into account in the PFES approaches and design and develop the pro- poor payment mechanism in order to achieve the two objectives of forest conservation and economic development.展开更多
Computer-aided process planning （CAPP） is an essential component of computer integrated manufacturing （CIM） system. A good process plan can be obtained by optimizing two elements, namely, operation sequence and th...Computer-aided process planning （CAPP） is an essential component of computer integrated manufacturing （CIM） system. A good process plan can be obtained by optimizing two elements, namely, operation sequence and the machining parameters of machine, tool and tool access direction （TAD） for each operation. This paper proposes a novel optimization strategy for process planning that considers different dimensions of the problem in parallel. A multi-dimensional tabu search （MDTS） algo-rithm based on this strategy is developed to optimize the four dimensions of a process plan, namely, operation sequence （OperSeq）, machine sequence （MacSeq）, tool sequence （TooISeq） and tool approach direction sequence （TADSeq）, sequentially and iteratively. In order to improve its efficiency and stability, tabu search, which is incorporated into the proposed MDTS al- gorithm, is used to optimize each component of a process plan, and some neighbourhood strategies for different components are presented for this tabu search algorithm. The proposed MDTS algorithm is employed to test four parts with different numbers of operations taken from the literature and compared with the existing algorithms like genetic algorithm （GA）, simulated annealing （SA）, tabu search （TS） and particle swarm optimization （PSO）. Experimental results show that the developed algo-rithm outperforms these algorithms in terms of solution quality and efficiency.展开更多
文摘The market-based incentive mechanism of payments for forest environmental services (PFES) seeks to capture part of the benefits derived from forest environmental services and channels them to forest resource owners/managers who generate these services, thus increases their incentives to conserve and manage forest resources. This paper examines some of the most important ethical issues entailed by PFES mechanism. The analysis shows that PFES may not always benefit the poor due to the comparative disadvantages of the poor and the complicated characteristics of forest ecosystem services. It is important and urgent to take ethical dimensions into account in the PFES approaches and design and develop the pro- poor payment mechanism in order to achieve the two objectives of forest conservation and economic development.
基金supported by the State Key Program of National Natural Science Foundation of China (Grant No. 51035001)National Natural Science Foundation of China (Grant Nos. 50825503, 50875101)
文摘Computer-aided process planning （CAPP） is an essential component of computer integrated manufacturing （CIM） system. A good process plan can be obtained by optimizing two elements, namely, operation sequence and the machining parameters of machine, tool and tool access direction （TAD） for each operation. This paper proposes a novel optimization strategy for process planning that considers different dimensions of the problem in parallel. A multi-dimensional tabu search （MDTS） algo-rithm based on this strategy is developed to optimize the four dimensions of a process plan, namely, operation sequence （OperSeq）, machine sequence （MacSeq）, tool sequence （TooISeq） and tool approach direction sequence （TADSeq）, sequentially and iteratively. In order to improve its efficiency and stability, tabu search, which is incorporated into the proposed MDTS al- gorithm, is used to optimize each component of a process plan, and some neighbourhood strategies for different components are presented for this tabu search algorithm. The proposed MDTS algorithm is employed to test four parts with different numbers of operations taken from the literature and compared with the existing algorithms like genetic algorithm （GA）, simulated annealing （SA）, tabu search （TS） and particle swarm optimization （PSO）. Experimental results show that the developed algo-rithm outperforms these algorithms in terms of solution quality and efficiency.
