Market structure and the value of overselling under stochastic demands

In the operations management literature, traditional revenue management focused on pricing and capacity allocation strategies in a two-period model with stochastic demand. Inspired by travel and lodging industries, we examine a two-period model in which each seller may also adopt the overselling strategy to customers whose valuations are differentiated by timing of arrivals. Widely seen as a popular hedge against consumers’ skipping reservations, we extend the stylized approaches of Biyalogorsky, Carmon, Fruchter, and Gerstner (1999) and Lim (2009) to understand the value of overselling under various market structures. We find that contrary to existing literature, the impact of period-two pricing competition from overselling spills over to period-one such that overselling may not always be a (weakly) dominant strategy once unlimited early demand ceases to hold in a duopoly regime. We provide some numerical studies on the existence of multiple equilibria at the capacity allocation level which actually lead to different selling strategies at the equilibrium despite identical market conditions and firm characteristics

Hydrodinamic Aspects of a High-Speed SWATH and New Hull Form

The main problems of high-speed ships operating in open seas are their insufficient seaworthiness and speed loss in high sea states. Small Water-plane Area Twin-Hulls (SWATH) are characterised by excellent seaworthiness, but the hull forms of a traditional SWATH are not suited for higher speeds. A new shape of underwater gondola has been developed for a semi-planing (S/P) SWATH. Additionally, hydrofoils can be applied to this ship to provide the optimal dynamic draught and trim, to mitigate motions in rough seas, and even to carry a part of the ship weight. The relative speed of this SWATH can be beneficially increased up to the displacement Froude number 3. Several concept designs addressing naval and civil transportation needs are outlined in this paper

Asymptomatic Fluid Collections Following Distal Pancreatectomy – Is Intervention Warranted?

Objective To determine the incidence, associated factors, natural history, and interventions for FCs

Integrated Transcriptome and Binding Sites Analysis Implicates E2F in the Regulation of Self-Renewal in Human Pluripotent Stem Cells

Rapid cellular growth and multiplication, limited replicative senescence, calibrated sensitivity to apoptosis, and a capacity to differentiate into almost any cell type are major properties that underline the self-renewal capabilities of human pluripotent stem cells (hPSCs). We developed an integrated bioinformatics pipeline to understand the gene regulation and functions involved in maintaining such self-renewal properties of hPSCs compared to matched fibroblasts. An initial genome-wide screening of transcription factor activity using in silico binding-site and gene expression microarray data newly identified E2F as one of major candidate factors, revealing their significant regulation of the transcriptome. This is underscored by an elevated level of its transcription factor activity and expression in all tested pluripotent stem cell lines. Subsequent analysis of functional gene groups demonstrated the importance of the TFs to self-renewal in the pluripotency-coupled context; E2F directly targets the global signaling (e.g. self-renewal associated WNT and FGF pathways) and metabolic network (e.g. energy generation pathways, molecular transports and fatty acid metabolism) to promote its canonical functions that are driving the self-renewal of hPSCs. In addition, we proposed a core self-renewal module of regulatory interplay between E2F and, WNT and FGF pathways in these cells. Thus, we conclude that E2F plays a significant role in influencing the self-renewal capabilities of hPSCs

The surface of iron molybdate catalysts used for the selective oxidation of methanol

The oxidation of methanol to formaldehyde is a major chemical process carried out catalytically and iron molybdate is one of the major catalysts for this process. In this paper we explore the nature of the active and selective surfaces of iron molybdate catalysts and show that the effective catalysts comprise molybdenum rich surfaces. We conclude that it is therefore important to maximise the surface area of these active catalysts and to this end we have studied catalysts made using a new physical grinding method with oxalic acid. For super-stoichiometric materials (Fe:Mo = 1:2.2) the reaction data show that physical mixing produces effective catalysts, possibly offering an improvement over the conventional co-precipitation method

Heritage Quay: What Will You Discover? Transforming the Archives of the University of Huddersfield, Yorkshire, UK

The Heritage Quay project is changing how archive services at the University of Huddersfield are delivered. This article examines how the Staff/Space/Collections dependency model and Customer Service Excellence framework have been used, and what lessons can be drawn for other archives

Expanding the Whipple Accelerated Recovery Pathway (WARP) To All Patients Undergoing Pancreaticoduodenectomy (PD)

Introduction: Pancreaticoduodenectomy (PD) is a complex abdominal procedure with high rates of perioperative morbidity. The Whipple Accelerated Recovery Pathway (WARP) was developed for highly selected patients undergoing PD to reduce hospital length of stay (LOS) and time to adjuvant therapy (TTAT), without increasing post-operative complications (POC) or readmission rates (RR). The purpose of this study was to determine if WARP could be implemented for all-risk patients undergoing PD. Methods: A single-institution, retrospective analysis of 281 patients implemented on the WARP between 2017-2020 was performed. 119 patients were categorized as WARP-eligible (WEPs) according to original inclusion criteria, and 162 were deemed WARP-ineligible (WIPs). Primary endpoints include LOS, TTAT, RR, and POC. Data was collected from Epic and a multivariate analysis with logistic regression was performed. Results: 28 POC were found in WEPs (23.5%) compared to 73 POC in WIPs (45.1%) (p\u3c0.05). Delayed gastric emptying (DGE) and post-operative pancreatic fistulas (POPF) were higher in WIPs: DGE was found in 10.2% of WEPs vs. 26.2% of WIPs (p\u3c0.05), while POPF was found in 5.1% of WEPs vs. 21% of WIPs (p\u3c0.05). Mean LOS was 5 days for WEPs vs. 6 days for WIPs (p\u3c0.05). TTAT was 55 days for WEPs, compared to 63 days in WIPs (p\u3c0.05). RR was 12.6% for WEPs and 23.5% for WIPs (p\u3c0.05). Discussion: WARP results in lowered POC, TTAT, LOS, and RR, cutting costs to patients. WARP may be expanded to all PD patients; however, WIPs may benefit from additional modifications that are specific for patient risk factor

A framework for convection and boundary layer parameterization derived from conditional filtering

A new theoretical framework is derived for parameterization of subgrid physical processes in atmospheric models; the application to parameterization of convection and boundary layer fluxes is a particular focus. The derivation is based on conditional filtering, which uses a set of quasi-Lagrangian labels to pick out different regions of the fluid, such as convective updrafts and environment, before applying a spatial filter. This results in a set of coupled prognostic equations for the different fluid components, including subfilter-scale flux terms and entrainment/detrainment terms. The framework can accommodate different types of approaches to parameterization, such as local turbulence approaches and mass-flux approaches. It provides a natural way to distinguish between local and nonlocal transport processes, and makes a clearer conceptual link to schemes based on coherent structures such as convective plumes or thermals than the straightforward application of a filter without the quasi-Lagrangian labels. The framework should facilitate the unification of different approaches to parameterization by highlighting the different approximations made, and by helping to ensure that budgets of energy, entropy, and momentum are handled consistently and without double counting. The framework also points to various ways in which traditional parameterizations might be extended, for example by including additional prognostic variables. One possibility is to allow the large-scale dynamics of all the fluid components to be handled by the dynamical core. This has the potential to improve several aspects of convection-dynamics coupling, such as dynamical memory, the location of compensating subsidence, and the propagation of convection to neighboring grid columns