24 research outputs found
Formulation and solution of a two-stage capacitated facility location problem with multilevel capacities
In this paper, the multi-product facility location problem in a two-stage supply chain is investigated. In this problem, the locations of depots (distribution centres) need to be determined along with their corresponding capacities. Moreover, the product flows from the plants to depots and onto customers must also be optimised. Here, plants have a production limit whereas potential depots have several possible capacity levels to choose from, which are defined as multilevel capacities. Plants must serve customer demands via depots. Two integer linear programming (ILP) models are introduced to solve the problem in order to minimise the fixed costs of opening depots and transportation costs. In the first model, the depot capacity is based on the maximum number of each product that can be stored whereas in the second one, the capacity is determined by the size (volume) of the depot. For large problems, the models are very difficult to solve using an exact method. Therefore, a matheuristic approach based on an aggregation approach and an exact method (ILP) is proposed in order to solve such problems. The methods are assessed using randomly generated data sets and existing data sets taken from the literature. The solutions obtained from the computational study confirm the effectiveness of the proposed matheuristic approach which outperforms the exact method. In addition, a case study arising from the wind energy sector in the UK is presented
Interdependence between transportation system and power distribution system: a comprehensive review on models and applications
The rapidly increasing penetration of electric vehicles in modern metropolises has been witnessed during the past decade, inspired by financial subsidies as well as public awareness of climate change and environment protection. Integrating charging facilities, especially high-power chargers in fast charging stations, into power distribution systems remarkably alters the traditional load flow pattern, and thus imposes great challenges on the operation of distribution network in which controllable resources are rare. On the other hand, provided with appropriate incentives, the energy storage capability of electric vehicle offers a unique opportunity to facilitate the integration of distributed wind and solar power generation into power distribution system. The above trends call for thorough investigation and research on the interdependence between transportation system and power distribution system. This paper conducts a comprehensive survey on this line of research. The basic models of transportation system and power distribution system are introduced, especially the user equilibrium model, which describes the vehicular flow on each road segment and is not familiar to the readers in power system community. The modelling of interdependence across the two systems is highlighted. Taking into account such interdependence, applications ranging from long-term planning to short-term operation are reviewed with emphasis on comparing the description of traffic-power interdependence. Finally, an outlook of prospective directions and key technologies in future research is summarized.fi=vertaisarvioitu|en=peerReviewed
Synthesis and biological evaluation of triazolylnucleosides as antibacterial and anticancer agents
A series of novel triazolylnucleosides has been efficiently synthesized (6a-h, 7a-b) by azide–alkyne 1,3-dipolar cycloaddition reaction and evaluated for antibacterial and anticancer activities. These nucleosides (6a-h) were screened against Staphylococcus aureus (ATCC 6538), gram-positive and Escherichia coli (ATCC 10536), Salmonella and Pseudomonas gram-negative bacterial strains. Among the series, three compounds (6c-e) exhibited significant levels of antibacterial activity against Staphylococcus aureus in reference to the standard drug, Levofloxacin. Triazolylnucleosides (6a-h) were also screened for anti-proliferative activities against cancer cell lines such as Huh-7 liver cancer cells. Three compounds (6e, 7a-b) have displayed promising anti-proliferative activity against Huh-7 and U87G cancer cells lines