Revenue Management in Multi-Firm, Multi-Product Price Competition

Dynamic pricing models in revenue management lack the ability to have multiple firms selling multiple product classes. In this thesis, a framework is created that allows for the construction of revenue management models with multiple firms, each selling multiple product types and where the firms have the ability to alter their prices instantly based on market conditions. The framework is a finite repeated game, where the optimal price for each state can be calculated through backwards induction. Conditions for existence of pure strategy Nash Equilibria are proven and conditions for unique pure strategy Nash Equilibria are discussed. We illustrate the pricing dynamics in a 2x1 and a 2x3 model. We recreate the well-known Netessine and Shumsky airline duopoly model but allow the firms to use dynamic pricing rather than booking limits. We find that in all cases the revenues from a dynamic pricing approach exceed those from booking limits. Through the use of three examples we show that our model provides vastly increased revenues over traditional models as it considers cross-price elasticities and how firms should alter their prices in response to the quantity levels of all products in the market

Experience Gained Investigating, Acquiring and Operating the First Traffic Speed Deflectometer in Australia

AbstractTo manage a pavement one must know something about its condition. The more you know, the better informed your decisions are. In Australia, road agencies have been utilising automated data collection systems to assess the functional condition of their pavements for the best part of the last two decades. However, during this time, the assessment of structural condition has been limited to manual, slow moving or point-based testing. This has made collection of this data across entire networks unrealistic, even though this information is desirable. Therefore, it is no surprise that Australian road agencies have shown significant interest in the Traffic Speed Deflectometer (TSD), a device they hope can provide the network-level structural information they desire.This paper provides the background leading to the initial Australian TSD trials and how ARRB Group was able to procure a TSD for Australia and New Zealand. It also details the integration of additional data collection modules and how they allow the functional and structural condition of the pavement to be measured at the same time. Finally, the paper documents some of the lessons learnt throughout the TSD's acceptance testing and first 18 months of use on the Australian and New Zealand road networks. During this time, over 60,000 km were surveyed with the TSD

The Performance of Concrete in a Marine Environment

This paper presents a summary of data from wide range of concretes following periods of marine exposure ranging up to 25 years. Data are presented from more than 100 different concrete mixtures. The various types of concrete include fibre-reinforced concrete (FRC), ultra-high performance concrete (UHPC), concrete with a range of supplementary cementing materials (SCM such as fly ash, slag, and silica fume) and replacement levels (e.g. up to 58% fly ash and 80% slag), lightweight-aggregate concrete (LWAC) and concrete containing alkali-silica reactive aggregate. Testing included measuring chloride concentration profiles, electrochemical corrosion measurements (for steel-reinforced concrete), and various electrical and mechanical properties, in addition to the examination of the microstructure. The data invariably show the importance of the binder type in terms of resistance to chloride ingress and the protection conferred on embedded steel reinforcement, however, the overall performance of SCM concrete was equivocal as high replacement levels were observed to lead to increased surface deterioration (scaling) in some cases. The performance of UHPC was exemplary with little significant chloride penetration and no evidence of surface deterioration after up to 20 years exposure and an estimated 2,000+ freeze-thaw cycles. Expansion (and cracking) due to alkali-silica reaction was observed to be reduced by seawater exposure but, perhaps more significantly, render air-entrained concrete highly susceptible to freeze-thaw damage when the expansion exceeded a certain threshold value. The data are discussed in terms of code requirements and the need for appropriate performance testing. The importance of long-term monitoring of concrete on exposure sites is also discussed

Residual stresses in aerospace structures reinforced with bonded crack retarders

Bonded crack retarder technology is an innovative concept to improve the fatigue performance of aircraft structures. Stiffening ‘straps’ are adhesively bonded to areas where potential fatigue cracking may occur. The straps retard the growth of fatigue cracks, by a combination of the local stiffening effect that reduces the crack driving force, and bridging in the wake of the crack. However, bonded crack retarder results in thermal residual stresses that may adversely affect the performance of the reinforced structure due to extensive fatigue loads in service. This is the first study where we have looked at the application of GLARE6/5 fibre-metal laminate as a bonded crack retarder onto a structural butt joint and simulated manhole mock-up assemblies containing cold-worked holes. Neutron diffraction was used for residual stress measurements. Results indicate that the strap-bonding process has no discernible effect on the magnitude of the compressive cold-working stresses. The use of bonded crack retarders should not, therefore, impair the benefits of cold working of fastener joints in aircraft structures

Effects of Selection for Kernel per Spike in Two Populations of Winter Wheat

Agronom

Entwicklungskonzepte für robuste Ökobetone

Beton ist der weltweit meist verwendete Baustoff und eines der meist produzierten Güter überhaupt. Seine Produktion in solch großen Mengen erfolgt jedoch unter erheblichen Eingriffen in die natürliche Umwelt, die sowohl signifikante Beiträge zu den anthropogenen CO2-Emissionen wie auch regionale Verknappungen der mineralischen Betonausgangsstoffe beinhalten. Ökobetone müssen sowohl eine verbesserte CO2-Bilanz aufweisen wie auch gegenüber Schwankungen in der Qualität ihrer Ausgangsstoffe robust sein, das heißt die für sie bestimmten Frisch- und Festbetoneigenschaften mit hoher Sicherheiz erzielen. Die granulometrischen Eigenschaften der Ausgangsstoffe und die Zusammensetzung der Gesteinskörnungen spielen hierfür eine zentrale Rolle. Dieser Beitrag erläutert Ansätze zur Entwicklung rheologisch robuster Ökobetone.Concrete is the most used construction material and one of the most produced goods of all. Its production in such large quantities causes great environmental impacts, including significant contributions to anthropogenic CO2-emissions and a decrease in the regional availability of high quality constituent materials. Green concretes must demonstrate an improved CO2-balance over their lifecycle and yet also be robust against variations in the quality of their constituent materials, meaning the desired properties of the concretes must be achieved with a high level of certainty. The granulometric properties of the aggregates are central to this challenge. This paper explains development procedures for rheologically robust concrete mixtures

Effect of impact damage on fatigue performance of structures reinforced with GLARE bonded crack retarders

Fibre-Metal Laminates (FML) such as GLARE are of interest as bonded crack retarders (BCR) to improve the fatigue performance of aircraft structures. The degradation of the performance of the crack retarder in service if subjected to damage is a critical factor in designing with this concept. Bonded assemblies of an aluminium alloy substrate reinforced with a GLARE strap were prepared, and were subjected to low velocity impact damage onto the GLARE, with impact energies ranging from 10 to 60J. The thermal residual stresses developed during the bonding process of the GLARE to the aluminium were determined using neutron diffraction, and the change in the thermal residual stresses owing to impact damage onto the GLARE was evaluated. Pre- and post-impact fatigue performance of the BCR assemblies has been investigated. The results show that the BCR provides an improvement in fatigue life, but the reduction is impaired following impact damage. The results show that monitoring of impact damage will be critical in the damage tolerance assurance for aerospace structures containing bonded crack retarders