Efficient Solution of a Multi-commodity, Two-stage Distribution Problem with Constraints on Assignment of Customers to Distribution Centres

A two-stage, distribution-planning problem is addressed. Customers are to be served with different commodities from a number of plants, through a number of intermediate distribution centres (DCs). The possible locations for the DCs are given. For each location, there is a fixed cost for opening the DC concerned, as well as an operating cost and a maximum capacity. The demand of each customer for each commodity is known, as well as shipping costs throughout. There are also two additional important requirements. First, each customer must be served with all the products it requires from a single distribution centre. Secondly, it must be possible to ascertain the plant origin of each product quantity delivered. The objective is to choose the locations for opening DCs such that the total cost is minimised. The problem is modelled as a mixed-integer-programming problem and solved by branch and bound. Lower bounds are calculated through a series of structural transformations. Much of the power of the solution scheme also stems from frequent generation of good upper bounds. Results of extensive computational experiments are given and discussed.     

A multilevel multilayer framework for manufacturing control

As a contribution to the debate on CAPM reference models derived from control theory concepts, we formulate the basic computer-aided production management problem from a control theoretic point of view and examine the main difficulties in using this crude framework as a basis for decision-making. Next, different hierarchical approaches are shown to be potentially of value in overcoming the two main difficulties highlighted by the control theoretic paradigm, i.e. dimensionality and the discrete event nature of manufacturing systems. In this context, we examine the literature concerned with both multilevel control as well as multilayer control where the notion of aggregation plays a key role. Next, a mixture of multilevel and multilayer control is used to provide a framework for production planning and scheduling for multiline batch manufacture with application to detergents plants. This framework would appear to be of values also in discrete parts manufacture and this is also highlighted.     

DQIT: /spl mu/-synthesis without D-scale fitting

A new approach called D-Q iteration (DQIT) for synthesizing robust H/sub /spl infin// controllers is proposed to avoid D-scale fitting in D-K iteration (DKIT). Each iteration includes a D-step and a Q-step. In the D-step, the D-scale at each frequency is optimized as in DKIT, but D-scale fitting is not required. In the Q-step, the scaled H/sub /spl infin// problem is approximated by a finite-dimensional Q-parameter optimization problem in the frequency domain, using D-scales directly. Numerical examples show significant improvement in some cases.     

Inelastic Damage Analysis of Reinforced Concrete Bridge Columns Based on Degraded Monotonic Energy

This paper summarizes the prediction of seismic damage of two existing bridges. The objective is to apply a damage index definition for reinforced concrete bridge columns under cyclic loading to existing bridge columns that might experience real seismic loading in the future, and to evaluate the ability of the damage index in describing the damage progression of the bridge columns during real seismic loading. Two existing bridges were selected from the Greater Vancouver Area in Canada. The first bridge, the Garneau Flyover, was designed in 1985 to ATC-6-1981 and is expected to have sufficient resistance to lateral earthquake loading. The second bridge, the Clydesdale Street Underpass, was designed long before ATC-6-1981 and is expected to show little or no lateral earthquake resistance. The damage index is applied to each of these structures, with columns modeled using the CANNY nonlinear structural analysis program. Shear and bond slip deformations were considered by making a simple modification to the column flexural properties. A series of nonlinear dynamic analyses were performed using records from the 1971 San Fernando, 1978 Miyaki-Oki (Japan), 1989 Loma Prieta, and 1999 Taiwan earthquakes fitted to the Vancouver firm ground spectrum. The calculated damage index provides a simple numerical indicator of the damage during an earthquake, easily computed from the results of a nonlinear dynamic analysis.     

Platinum-Based Regimens Are Active in Advanced Pediatric-Type Rhabdomyosarcoma in Adults and Depending on HMGB1 Expression

Rhabdomyosarcoma (RMS) in adults is a rare and aggressive disease, which lacks standard therapies for relapsed or advanced disease. This retrospective study aimed to describe the activity of BOMP-EPI (bleomycin, vincristine, methotrexate and cisplatin alternating with etoposide, cisplatin and ifosfamide), an alternative platinum-based regimen, in adult patients with relapsed/metastatic RMS. In the study, 10 patients with RMS with a median age at diagnosis of 20.8 years and a female/male distribution of 6/4 received a mean of 2.5 cycles of BOMP-EPI. The best RECIST response was a complete response in 1/10 (10%) patients, a partial response in 5/10 (50%), stable disease in 3/10 (30%) and progression in 1/10 (10%). With a median follow-up in the alive patients from the start of therapy of 30.5 months (15.7–258), all patients progressed with a median progression-free survival of 8.47 months (95% CI 8.1–8.8), and 7/10 patients died with a median overall survival of 24.7 months (95% CI 13.7–35.6). BOMP-EPI was an active chemotherapy regimen in adults with pediatric-type metastatic RMS, with outcomes in terms of survival that seem superior to what was expected for this poor-prognosis population. Low HMGB1 expression level was identified as a predictive factor of better response to this treatment.