Hub-and-Spoke (H&S) network modeling is a form of transport topology optimization in which joins are connected through intermediate hub nodes. The Short Sea Shipping (SSS) problem aims to efficiently disperse passenger flows involving multiple vessel routes and intermediary hubs passengers transferred their final destination. contains elements the Travelling Salesman, with different levels ...

Many transport service providers operate on hub-and-spoke network structures. Major operators may have several dedicated hub facilities that are leased for a time horizon rather than being owned or constructed. For a given discrete planning horizon, service providers must decide on the location of the hub ports (i.e. terminals), the period when the lease contract starts, the period when the exi...

wanted to change their work. The mean score of MFI and job demand of our sample were 50.6 (SD: 12.5) and 36.1 (SD: 4.1), respectively. Multivariate logistic regression analysis (Table 1) showed that salarydissatisfaction significantly increased the incidence of depressive symptoms with adjusted odds ratio (OR) 1.9 (1.1–3.6). Meanwhile, physical fatigue, mental fatigue, and high job demand were ...

OBJECTIVES Regular and quality CD4 testing is essential to monitor disease progression in people living with HIV. In Haiti, most laboratories have limited infrastructure and financial resources and have relied on manual laboratory techniques. We report the successful implementation of a national specimen referral network to rapidly increase patient coverage with quality CD4 testing while at the...

of profitability, spatially spread demand, and intense competition have incited a trend to seek solutions through ICT and the Internet (3). One manifestation of this is an increase in collaboration among small to medium-sized LTL carriers. That is, small to medium-sized carriers have begun to develop strategies that exploit synergies (such as excess capacity, overlapping lanes, and facilities),...

This study formulates a two-objective model by individually minimizing shipping costs and inventory costs to decide whether to route a shipment through a hub or directly to its destination. First, shipping and inventory cost functions are formulated for a multi-port calling route. Shipping costs include capital and operating cost, fuel cost and port charge, while inventory costs include waiting...

Consider networks on n vertices at average density 1 per unit area. We seek a network that minimizes total length subject to some constraint on journey times, averaged over sourcedestination pairs. Suppose journey times depend on both route-length and number of hops. Then for the constraint corresponding to an average of 3 hops, the length of the optimal network scales as n13/10. Alternatively,...

The Universiteit van Amsterdam (UvA) [12] is geographically displaced throughout the millennium old capital city. As a reflection of this and of the devolved powers of the organization there exists’s a diversity of information systems and solutions scattered physically, architecturally and administratively. To lower cost of maintenance and to approach, in the near future, a more uniform and con...

A sustainable alternative to fossil fuels is biomass. The design of cost-efficient biomass networks necessary compete with nonrenewable resources. creation integrated supply chain (BSC) network models and solution procedures can contribute the achievement this goal. In particular, emerging bioenergy industry must take advantage economies scale in transportation minimize final product’s cost. Hu...