Implementing effective cost management approaches has recently gained momentum due to intense competition and increasing customer demands. Moreover, effective cost management approaches have contributed to firms＇ com...Implementing effective cost management approaches has recently gained momentum due to intense competition and increasing customer demands. Moreover, effective cost management approaches have contributed to firms＇ competitive advantage in relation to cost leadership strategy. Consequently, firms have implemented contemporary cost management systems, such as activity-based management, business process re-engineering, life-cycle costing, target costing, and theory of constraint （TOC）, to enable them to become low-cost producers and compete effectively and sustain their performance. Furthermore, focusing on cost management to improve profitability has led to the integration of activity-based costing （ABC） and TOC. Therefore, the aim of this study is to review literature and discuss how integration of ABC and TOC can result in improved and sustained cost management. While these methods have different approaches in addressing cost management, treating them as complementary cost management approaches can result in improved cost management due to improved product costing, improved cost reporting, improved product-mix decisions, and improved cycle-time management. Improvement in cost management will then result in sustained cost management. Sustained cost management is further enhanced with the investment in information customer and shareholder value technology that supports cross-functional decision making to continue creating to remain competitive in the market.展开更多
Based on the molecular theory of non-linear viscoelasticity with constrained entanglements in polymer melts, the material functions in simple shear flow were formulated, the theoretical relations between. eta((gamma) ...Based on the molecular theory of non-linear viscoelasticity with constrained entanglements in polymer melts, the material functions in simple shear flow were formulated, the theoretical relations between. eta((gamma) over dot), psi (10)((gamma) over dot) and shear rate ((gamma) over dot), and topologically constrained dimension number n ' and a were derived. Linear viscoelastic parameters (eta (0) and G(N)(0)) and topologically constrained dimension number (n ' a and <(<upsilon>)over bar>) as a function of the primary molecular weight (M-n), molecular weight between entanglements (M-C) and the entanglement sites sequence distribution in polymer chain were determined. A new method for determination of viscoelastic parameters (eta (0), psi (10), G(N)(0) and J(e)(0)), topologically constrained dimension number (n ', a and v) and molecular weight (M-n, M-c and M-e) from the shear flow measurements was proposed. It was used to determine those parameters and structures of HDPE, making a good agreement between these values and those obtained by other methods. The agreement affords a quantitative verification for the molecular theory of nonlinear viscoelasticity with constrained entanglement in polymer melts.展开更多
In WSNs, energy conservation is the primary goal, while throughput and delay are less important. This re-sults in a tradeoff between performance (e.g., throughput, delay, jitter, and packet-loss-rate) and energy con-s...In WSNs, energy conservation is the primary goal, while throughput and delay are less important. This re-sults in a tradeoff between performance (e.g., throughput, delay, jitter, and packet-loss-rate) and energy con-sumption. In this paper, the problem of energy-efficient MAC protocols in WSNs is modeled as a game-theoretic constraint optimization with multiple objectives. After introducing incompletely cooperative game theory, based on the estimated game state (e.g., the number of competing nodes), each node independ-ently implements the optimal equilibrium strategy under the given constraints (e.g., the used energy and QoS requirements). Moreover, a simplified game-theoretic constraint optimization scheme (G-ConOpt) is pre-sented in this paper, which is easy to be implemented in current WSNs. Simulation results show that G-ConOpt can increase system performance while still maintaining reasonable energy consumption.展开更多
Aspects of the general Vlasov theory are examined separately as applied to a thin-walled channel section cantilever beam under free-end end loading. In particular, the flexural bending and shear that arise under trans...Aspects of the general Vlasov theory are examined separately as applied to a thin-walled channel section cantilever beam under free-end end loading. In particular, the flexural bending and shear that arise under transverse shear and axial torsional loading are each considered theoretically. These analyses involve the location of the shear centre at which transverse shear forces when applied do not produce torsion. This centre, when taken to be coincident with the centre of twist implies an equivalent reciprocal behaviour. That is, an axial torsion applied concentric with the shear centre will twist but not bend the beam. The respective bending and shear stress conversions are derived for each action applied to three aluminium alloy extruded channel sections mounted as cantilevers with a horizontal principal axis of symmetry. Bending and shear are considered more generally for other thin-walled sections when the transverse loading axes at the shear centre are not parallel to the section = s centroidal axes of principal second moments of area. The fixing at one end of the cantilever modifies the St Venant free angular twist and the free warping displacement. It is shown from the Wagner-Kappus torsion theory how the end constrained warping generates an axial stress distribution that varies with the length and across the cross-section for an axial torsion applied to the shear centre. It should be mentioned here for wider applications and validation of the Vlasov theory that attendant papers are to consider in detail bending and torsional loadings applied to other axes through each of the centroid and the web centre. Therein, both bending and twisting arise from transverse shear and axial torsion applied to each position being displaced from the shear centre. Here, the influence of the axis position upon the net axial and shear stress distributions is to be established. That is, the net axial stress from axial torsional loading is identified with the sum of axial stress due to bending and axial stress arising from constrained warping displacements at the fixing. The net shear stress distribution overlays the distributions from axial torsion and that from flexural shear under transverse loading. Both arise when transverse forces are displaced from the shear centre.展开更多
简要分析了产品冲突问题的约束理论(theory of constraints,TOC)思维流程,介绍了发明问题解决理论(theory of inventive problem solving,TRIZ)创新设计过程.描述了TOC中5个逻辑图表及其相互之间的关系.提出一种将TRIZ与TOC相结合的产...简要分析了产品冲突问题的约束理论(theory of constraints,TOC)思维流程,介绍了发明问题解决理论(theory of inventive problem solving,TRIZ)创新设计过程.描述了TOC中5个逻辑图表及其相互之间的关系.提出一种将TRIZ与TOC相结合的产品冲突问题解决过程构造模型的设计方法,利用所构造的产品当前实现树、逻辑图表和TRIZ的矛盾冲突解决矩阵来解决产品冲突问题.实例证明TRIZ与TOC相结合的方法用于驱动产品创新设计是切实可行的.展开更多
针对大规模Job Shop调度问题,提出了一种基于TOC(theory of constraints)的免疫遗传算法。该算法依据TOC理论中瓶颈机约束生产系统性能的思想,利用瓶颈机器的特性,在染色体编码及遗传操作过程中,对瓶颈机与非瓶颈机采用不同的处理方式,...针对大规模Job Shop调度问题,提出了一种基于TOC(theory of constraints)的免疫遗传算法。该算法依据TOC理论中瓶颈机约束生产系统性能的思想,利用瓶颈机器的特性,在染色体编码及遗传操作过程中,对瓶颈机与非瓶颈机采用不同的处理方式,以使瓶颈工序得到最优化调度。而非瓶颈工序在满足瓶颈工序的调度方案的基础上进行快速调度,降低大规模作业车间调度问题的复杂度,提高算法的求解效率。为提高算法求解质量,克服遗传算法的随机性及迭代退化问题,将TOC理论中的瓶颈机器拓展至瓶颈工件,提出候选瓶颈工件集及瓶颈工件的定义。通过对瓶颈机接种"瓶颈工件邻域对换"免疫算子,充分利用种群中个体的特征信息,辅助遗传算法的优化过程。仿真结果表明:瓶颈特征的应用以及免疫算子的融入是有效的,免疫遗传算法可以在较短的时间内求得令人满意的解。展开更多
分析了混流生产条件下生产作业计划的特点和MRPⅡ/ERP、JIT的局限,提出并阐述了混流生产条件基于约束理论TOC(Theory of Corstraints)制定生产作业计划的关键问题,即瓶颈环节的确定和转移问题、生产系统中批量和提前期的联合确定问题以...分析了混流生产条件下生产作业计划的特点和MRPⅡ/ERP、JIT的局限,提出并阐述了混流生产条件基于约束理论TOC(Theory of Corstraints)制定生产作业计划的关键问题,即瓶颈环节的确定和转移问题、生产系统中批量和提前期的联合确定问题以及缓冲位置和缓冲大小的确定问题,对解决这些问题的思路和发展作了探讨。展开更多
文摘Implementing effective cost management approaches has recently gained momentum due to intense competition and increasing customer demands. Moreover, effective cost management approaches have contributed to firms＇ competitive advantage in relation to cost leadership strategy. Consequently, firms have implemented contemporary cost management systems, such as activity-based management, business process re-engineering, life-cycle costing, target costing, and theory of constraint （TOC）, to enable them to become low-cost producers and compete effectively and sustain their performance. Furthermore, focusing on cost management to improve profitability has led to the integration of activity-based costing （ABC） and TOC. Therefore, the aim of this study is to review literature and discuss how integration of ABC and TOC can result in improved and sustained cost management. While these methods have different approaches in addressing cost management, treating them as complementary cost management approaches can result in improved cost management due to improved product costing, improved cost reporting, improved product-mix decisions, and improved cycle-time management. Improvement in cost management will then result in sustained cost management. Sustained cost management is further enhanced with the investment in information customer and shareholder value technology that supports cross-functional decision making to continue creating to remain competitive in the market.
基金The authors gratefully a.cknowledge financial supportfrom th6 Natiol-al Natural Science Foundatiol- of CI-h-a. The number of
文摘Based on the molecular theory of non-linear viscoelasticity with constrained entanglements in polymer melts, the material functions in simple shear flow were formulated, the theoretical relations between. eta((gamma) over dot), psi (10)((gamma) over dot) and shear rate ((gamma) over dot), and topologically constrained dimension number n ' and a were derived. Linear viscoelastic parameters (eta (0) and G(N)(0)) and topologically constrained dimension number (n ' a and <(<upsilon>)over bar>) as a function of the primary molecular weight (M-n), molecular weight between entanglements (M-C) and the entanglement sites sequence distribution in polymer chain were determined. A new method for determination of viscoelastic parameters (eta (0), psi (10), G(N)(0) and J(e)(0)), topologically constrained dimension number (n ', a and v) and molecular weight (M-n, M-c and M-e) from the shear flow measurements was proposed. It was used to determine those parameters and structures of HDPE, making a good agreement between these values and those obtained by other methods. The agreement affords a quantitative verification for the molecular theory of nonlinear viscoelasticity with constrained entanglement in polymer melts.
文摘In WSNs, energy conservation is the primary goal, while throughput and delay are less important. This re-sults in a tradeoff between performance (e.g., throughput, delay, jitter, and packet-loss-rate) and energy con-sumption. In this paper, the problem of energy-efficient MAC protocols in WSNs is modeled as a game-theoretic constraint optimization with multiple objectives. After introducing incompletely cooperative game theory, based on the estimated game state (e.g., the number of competing nodes), each node independ-ently implements the optimal equilibrium strategy under the given constraints (e.g., the used energy and QoS requirements). Moreover, a simplified game-theoretic constraint optimization scheme (G-ConOpt) is pre-sented in this paper, which is easy to be implemented in current WSNs. Simulation results show that G-ConOpt can increase system performance while still maintaining reasonable energy consumption.
文摘Aspects of the general Vlasov theory are examined separately as applied to a thin-walled channel section cantilever beam under free-end end loading. In particular, the flexural bending and shear that arise under transverse shear and axial torsional loading are each considered theoretically. These analyses involve the location of the shear centre at which transverse shear forces when applied do not produce torsion. This centre, when taken to be coincident with the centre of twist implies an equivalent reciprocal behaviour. That is, an axial torsion applied concentric with the shear centre will twist but not bend the beam. The respective bending and shear stress conversions are derived for each action applied to three aluminium alloy extruded channel sections mounted as cantilevers with a horizontal principal axis of symmetry. Bending and shear are considered more generally for other thin-walled sections when the transverse loading axes at the shear centre are not parallel to the section = s centroidal axes of principal second moments of area. The fixing at one end of the cantilever modifies the St Venant free angular twist and the free warping displacement. It is shown from the Wagner-Kappus torsion theory how the end constrained warping generates an axial stress distribution that varies with the length and across the cross-section for an axial torsion applied to the shear centre. It should be mentioned here for wider applications and validation of the Vlasov theory that attendant papers are to consider in detail bending and torsional loadings applied to other axes through each of the centroid and the web centre. Therein, both bending and twisting arise from transverse shear and axial torsion applied to each position being displaced from the shear centre. Here, the influence of the axis position upon the net axial and shear stress distributions is to be established. That is, the net axial stress from axial torsional loading is identified with the sum of axial stress due to bending and axial stress arising from constrained warping displacements at the fixing. The net shear stress distribution overlays the distributions from axial torsion and that from flexural shear under transverse loading. Both arise when transverse forces are displaced from the shear centre.
文摘简要分析了产品冲突问题的约束理论(theory of constraints,TOC)思维流程,介绍了发明问题解决理论(theory of inventive problem solving,TRIZ)创新设计过程.描述了TOC中5个逻辑图表及其相互之间的关系.提出一种将TRIZ与TOC相结合的产品冲突问题解决过程构造模型的设计方法,利用所构造的产品当前实现树、逻辑图表和TRIZ的矛盾冲突解决矩阵来解决产品冲突问题.实例证明TRIZ与TOC相结合的方法用于驱动产品创新设计是切实可行的.
文摘针对大规模Job Shop调度问题,提出了一种基于TOC(theory of constraints)的免疫遗传算法。该算法依据TOC理论中瓶颈机约束生产系统性能的思想,利用瓶颈机器的特性,在染色体编码及遗传操作过程中,对瓶颈机与非瓶颈机采用不同的处理方式,以使瓶颈工序得到最优化调度。而非瓶颈工序在满足瓶颈工序的调度方案的基础上进行快速调度,降低大规模作业车间调度问题的复杂度,提高算法的求解效率。为提高算法求解质量,克服遗传算法的随机性及迭代退化问题,将TOC理论中的瓶颈机器拓展至瓶颈工件,提出候选瓶颈工件集及瓶颈工件的定义。通过对瓶颈机接种"瓶颈工件邻域对换"免疫算子,充分利用种群中个体的特征信息,辅助遗传算法的优化过程。仿真结果表明:瓶颈特征的应用以及免疫算子的融入是有效的,免疫遗传算法可以在较短的时间内求得令人满意的解。
文摘分析了混流生产条件下生产作业计划的特点和MRPⅡ/ERP、JIT的局限,提出并阐述了混流生产条件基于约束理论TOC(Theory of Corstraints)制定生产作业计划的关键问题,即瓶颈环节的确定和转移问题、生产系统中批量和提前期的联合确定问题以及缓冲位置和缓冲大小的确定问题,对解决这些问题的思路和发展作了探讨。
