Solution algorithms for the parallel replacement problem under economy of scale

1998 ◽  
Vol 45 (3) ◽  
pp. 279-295 ◽  
Author(s):  
Zhi-Long Chen
Keyword(s):  
Economy Of Scale ◽  
Solution Algorithms ◽  
Parallel Replacement ◽  
Replacement Problem

Improving Efficiency in Robot Assisted Belt Grinding of High Performance Materials

2014 ◽  
Vol 907 ◽  
pp. 139-149 ◽  
Author(s):  
Eckart Uhlmann ◽  
Florian Heitmüller
Keyword(s):  
Gas Turbines ◽  
High Performance ◽  
Scale Effects ◽  
Turbine Blades ◽  
Repair Process ◽  
Industrial Robots ◽  
Robot Assisted ◽  
Belt Grinding ◽  
Economy Of Scale ◽  
The Individual

In gas turbines and turbo jet engines, high performance materials such as nickel-based alloys are widely used for blades and vanes. In the case of repair, finishing of complex turbine blades made of high performance materials is carried out predominantly manually. The repair process is therefore quite time consuming. And the costs of presently available repair strategies, especially for integrated parts, are high, due to the individual process planning and great amount of manually performed work steps. Moreover, there are severe risks of partial damage during manually conducted repair. All that leads to the fact that economy of scale effects remain widely unused for repair tasks, although the piece number of components to be repaired is increasing significantly. In the future, a persistent automation of the repair process chain should be achieved by developing adaptive robot assisted finishing strategies. The goal of this research is to use the automation potential for repair tasks by developing a technology that enables industrial robots to re-contour turbine blades via force controlled belt grinding.

scholarly journals Public-private cooperation and agricultural development in Sub-Saharan Africa: a review of Nigerian growth enhancement scheme and e-voucher program

Food Security ◽  
2020 ◽  
Author(s):  
Emmanuel Olatunbosun Benjamin ◽  
Oreoluwa Ola ◽  
Hannes Lang ◽  
Gertrud Buchenrieder
Keyword(s):  
Information And Communication Technologies ◽  
Agricultural Development ◽  
Sub Saharan Africa ◽  
Living Standard ◽  
Growth Enhancement ◽  
Extension Services ◽  
Voucher Program ◽  
Economy Of Scale ◽  
Sub Saharan ◽  
The Impact

AbstractThe Growth Enhancement Scheme and e-voucher program, rolled out across Nigeria in 2011 by the federal government, provided the institutional basis for private agro-dealers to engage in the distribution of subsidized fertilizer, improved seeds and extension services to farmers. However, the impact of this policy on different modes of extension service delivery is still missing in literature. We apply an Ordinary Least Squared and Difference-in-Difference methodology on the (2010 and 2012) Living Standard Measurement Study of the World Bank. The results suggest that extension visitations as well as public extension services positively influence farm revenue. Furthermore, a substantial increase in fertilizer expenditure by farmers was observed, due to the e-voucher program, which could have contributed to the improved agricultural output witnessed in Nigeria post-Growth Enhancement Scheme era. Governments across Sub-Saharan Africa should implement policies that harness the economy of scale and scope of the private sector as well as information and communication technologies in delivering on time and adequate agricultural inputs to farmers.

Discrete Dynamic Shortest Path Problems in Transportation Applications: Complexity and Algorithms with Optimal Run Time

1998 ◽  
Vol 1645 (1) ◽  
pp. 170-175 ◽  
Author(s):  
Ismail Chabini
Keyword(s):  
Large Scale ◽  
Shortest Paths ◽  
Transportation Systems ◽  
Solution Algorithm ◽  
Shortest Path Problems ◽  
Discrete Dynamic ◽  
Solution Algorithms ◽  
Dynamic Network Models ◽  
Early Results ◽  
Run Time

A solution is provided for what appears to be a 30-year-old problem dealing with the discovery of the most efficient algorithms possible to compute all-to-one shortest paths in discrete dynamic networks. This problem lies at the heart of efficient solution approaches to dynamic network models that arise in dynamic transportation systems, such as intelligent transportation systems (ITS) applications. The all-to-one dynamic shortest paths problem and the one-to-all fastest paths problems are studied. Early results are revisited and new properties are established. The complexity of these problems is established, and solution algorithms optimal for run time are developed. A new and simple solution algorithm is proposed for all-to-one, all departure time intervals, shortest paths problems. It is proved, theoretically, that the new solution algorithm has an optimal run time complexity that equals the complexity of the problem. Computer implementations and experimental evaluations of various solution algorithms support the theoretical findings and demonstrate the efficiency of the proposed solution algorithm. The findings should be of major benefit to research and development activities in the field of dynamic management, in particular real-time management, and to control of large-scale ITSs.

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