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A Clustered Overflow Configuration of Inpatient Beds in Hospitals
Problem Definition: The shortage of inpatient beds is a major cause of delays and cancellations in many hospitals. It may also lead to patients being admitted to inappropriate wards, whereby resulting in a lower quality of care and a longer length of stay.
Academic/Practical Relevance: Investment in additional beds is not always feasible. Instead, new and creative solutions for a more efficient use of existing resources must be sought.
Methodology: We propose a new configuration of inpatient beds which we call the clustered overflow configuration. In this configuration, patients who are denied admission to their primary wards as a result of beds being fully occupied are admitted to overflow wards, with each designated to serve overflows from a certain subset of specialties and providing the same quality of care as in primary wards. We propose two different formulations for partitioning and bed allocation in the proposed configuration: one minimizing the sum of average daily costs of turning patients away and nursing teams, and another minimizing the numbers turned away subject to nursing cost falling below a given threshold. We heuristically solve instances from both formulations.
Results: Applying the models to real data shows that the configurations obtained from our models compare very well with the other configurations proposed in the literature, provided that
patients' willingness to wait is relatively short.
Managerial Implications: The proposed configuration provides the combined advantages of the dedicated configuration, wherein patients are only admitted to their primary wards, and the exible configuration, in which all specialties share a single ward. On the other hand, it restricts the adverse impacts of pooling and minimizes cross-training costs through appropriate partitioning and bed allocation. As such, it serves as a viable alternative to existing inpatient configurations
Degassing process of Satsuma-Iwojima volcano, Japan: Supply of volatile components from a deep magma chamber
Viscosity of andesitic lava and its implications for possible drain-back processes in the 2011 eruption of the Shinmoedake volcano, Japan
Synchronous degassing patterns of the neighbouring volcanoes Llaima and Villarrica in south-central Chile: the influence of tidal forces
Measuring volcanic degassing of SO2 in the lower troposphere with ASTER band ratios
We present a new method for measuring SO2 with the data from the ASTER (Advanced Spaceborne Thermal
Emission and Reflectance radiometer) orbital sensor. The method consists of adjusting the SO2 column
amount until the ratios of radiance simulated on several ASTER bands match the observations. We present a
sensitivity analysis for this method, and two case studies. The sensitivity analysis shows that the selected
band ratios depend much less on atmospheric humidity, sulfate aerosols, surface altitude and emissivity than
the raw radiances. Measurements with b25% relative precision are achieved, but only when the thermal
contrast between the plume and the underlying surface is higher than 10 K. For the case studies we focused
on Miyakejima and Etna, two volcanoes where SO2 is measured regularly by COSPEC or scanning DOAS. The
SO2 fluxes computed from a series of ten images of Miyakejima over the period 2000–2002 is in agreement
with the long term trend of measurement for this volcano. On Etna, we compared SO2 column amounts
measured by ASTER with those acquired simultaneously by ground-based automated scanning DOAS. The
column amounts compare quite well, providing a more rigorous validation of the method. The SO2 maps
retrieved with ASTER can provide quantitative insights into the 2D structure of non-eruptive volcanic
plumes, their dispersion and their progressive depletion in SO2