Product Differentiation and Film Programming Choice: Do First-Run Movie Theatres Show the Same Films?

We present an empirical analysis of product differentiation using a new dynamic panel data set on film programming choice in a major U.S. metropolitan motion-pictures exhibition market. Using these data, we compute two measures of film programming choice, which allow us to investigate the determinants of strategic product differentiation in a multi-characteristics space. Our evidence is consistent with the idea that the degree of product differentiation between theatre pairs reflects a balance between strategic concerns and contractual constraints. Similarity in one dimension is offset by differentiation in others. Our results further suggest that the degree of product differentiation is negatively related to market size. Finally, we find thta ownership matters theatres under common ownership make more similar programming choices than theatres with different owners.

Product Differentiation and Film Programming Choice: Do First-Run Movie Theatres Show the Same Films?

We present an empirical analysis of product differentiation using a rich new dynamic panel data set on film programming choice in a major U.S. metropolitan motion-pictures exhibition market. These data allow us to investigate the determinants of strategic product differentiation in a multicharacteristics space. We find evidence of stability in the degree of product differentiation over time, but also find that the degree of product differentiation between theatre pairs reflects a balance between strategic concerns and contractual constraints. Similarity in one dimension is offset by differentiation in others. Finally, we find that theatres under common ownership make more similar programming choices than theatres with different owners.

Tensiography and Liquid Drop Metrology

This research focused on drop metrology and the use of camera technology and vibration analysis influence on theoretical and practical tensiography. Drop shape and Tensiography are explained and how they relate to each other. Studies shows a relationship between vibration frequency and surface tension of liquids. However they also reveal the need for a theoretical understanding of the vibration tensiotrace of drops. Camera studies on large diameter dropheads used in tensiography are explored. Various image analysis methods were investigated for determining drop shape from camera images. Examination of the digital image reveals measurement issues. High speed camera images reveal new details of the drop separation process. An examination of drop modelling methods from camera images and the principles of such modelling were undertaken. Camera studies were developed which enabled the practical investigation of edge-detection. The theory developed links the drop shape with the tensiotrace of drops examined. The ray tracing method of the modelling of drop shape would have to be consolidated by establishing a definitive relationship between drop shape and the tensiotrace. This lead to acquiring photo images of real drops to get the profile of its edge or the drop shape. Various methods are used and assumptions are made in finding the edge of a drop from a photo image, in particular to the measurement of length, radii and angles

Increased Tolerance to Abiotic Stresses in Tobacco Plants Expressing a Barley Cell Wall Peroxidase

Tensiography is a technique that determines the physical and chemical properties of a liquid by illuminating a growing pendant drop from within using a source fibre. Light reflected internally at the surface of the drop is recieved by a collector fibre and is converted into an electric signal called a tensiotrace, which is a graph of reflected light as a function of drop volume. The instrument obtaining this signal is called multianalyser. A numerical model that simulates tensiotraces through a raytracing analysis (RAST - Raytracing Analysis for the Simulation of Tensiotraces) of the multianalyser as been developed to define theoretically how the tensiotrace describes the physical and chemical properties of a liquid. The purpose of this study is to investigate the model as an engineering/design assistant leading to discoveries and improvements to the multianalyser

RAST Model: Simulation of Tensiotraces to Facilitate Drophad Engineering

Tensiography is a technique that determines the physical and chemical properties of a liquid by illuminating a growing pendant drop from within using a source fibre. Light reflected internally at the surface of the drop is recieved by a collector fibre and is converted into an electric signal called a tensiotrace, which is a graph of reflected light as a function of drop volume. The instrument obtaining this signal is called multianalyser. A numerical model that simulates tensiotraces through a raytracing analysis (RAST - Raytracing Analysis for the Simulation of Tensiotraces) of the multianalyser as been developed to define theoretically how the tensiotrace describes the physical and chemical properties of a liquid. The purpose of this study is to investigate the model as an engineering/design assistant leading to discoveries and improvements to the multianalyser

Neutron background in large-scale xenon detectors for dark matter searches

Simulations of the neutron background for future large-scale particle dark matter detectors are presented. Neutrons were generated in rock and detector elements via spontaneous fission and (alpha,n) reactions, and by cosmic-ray muons. The simulation techniques and results are discussed in the context of the expected sensitivity of a generic liquid xenon dark matter detector. Methods of neutron background suppression are investigated. A sensitivity of $10^{-9}-10^{-10}$ pb to WIMP-nucleon interactions can be achieved by a tonne-scale detector.Comment: 35 pages, 13 figures, 2 tables, accepted for publication in Astroparticle Physic

Magnetic inspection platform for teleoperated remote inspections of complex geometry

The NDE industry is under constant pressure to increase inspection speeds, while simultaneously reducing costs to keep up with the ever-expanding demands of providing robust inspection for new infrastructure as well as ongoing inspections for currently operating facilities, and the increasing rise in the need for extensions in the planned life of existing plants. Currently, setting up an automated phased array ultrasonic inspection requires significant manpower, especially on components with complex geometry, this often exposes operators to hazardous environments. This is a particular problem with conventional ultrasonic NDT where operators must regularly exchange probes (an ‘intervention’). Furthermore, inspections are often carried out during planned outages, and the necessary installation time of rigging can represent a significant part of the inspection cost. To alleviate these challenges, several specialised robotic systems have been developed in industry for performing NDE in areas with well-defined geometries. However, these systems are often limited by a high degree of manual intervention, a lack of general-purpose design, and unsophisticated brute-force data acquisition with little to no data interpretation. The development of next generation, automated NDE solutions present considerable improvements to the current state of design such as reduced inspection time, greater separation of data capture and analysis, data localization – data are intrinsically encoded with the position they were captured. These benefits lead to a reduction in plant downtime & operator dosage. The platform presented will achieve these improvements through a set of universal automated deployment tools, implemented through hardware and software advances. By creating a platform consisting of a motorised magnetic base paired with a miniature robotic arm, a very capable and adaptable system is formed. This allows for different sensing modalities with an initial focus on phased array ultrasonics to be delivered accurately and repeatably to the target inspection site. Furthermore, by introducing additional perceptual sensors such as cameras, laser scanners, & a force-torque sensor the system can understand the environment in which it is operating. Through these sensors the user may guide the robot through the plant remotely in a safe and controlled manner. In addition to this these sensors may be used to generate scan paths of critical areas with unknown geometry on the fly as well as adapt the path in a conformable manner

A pulsed eddy current sensor for UAV deployed pipe thickness measurement

The necessity to inspect essential infrastructure such as oil and gas pipelines for wear, and deterioration highlights the critical role of enhancing Non-Destructive Testing (NDT) methods. Routine inspection for wall thinning is essential for monitoring the structural integrity of these assets and preventing serious accidents. Given the challenges of manned access to these assets, Unmanned Aerial Vehicles (UAVs) equipped with high-resolution cameras are increasingly being adopted as a safer and more efficient alternative for remote inspections. However, their inability to detect sub-surface defects or assess thickness under coatings restricts their applicability. Pulsed Eddy Current (PEC) technology provides a promising solution, capable of assessing thickness beneath coatings and addressing the shortcomings of camera-based inspections. Traditional PEC systems are effective but bulky and difficult to incorporate within mobile platforms, limiting their versatility and ease of deplorability. This paper presents a novel, compact PEC sensor system to address these challenges, enhancing PEC inspections for mobile platforms. The system can be effectively mounted on a crawler-hybrid UAV, facilitating detailed 360-degree inspections of pipe surfaces. Findings detail the autonomous deployment of this PEC system via a UAV for the non-intrusive assessment of wall thickness. Finite element analysis was used for the design and performance evaluation of the PEC system. Integrated with a multirotor-crawler UAV engineered for navigating through complex pipeline environments, this mobile PEC system can conduct thorough evaluations of steel pipeline wall thinning. The system delivers a sensing method that achieves accurate thickness measurements, with errors under 4.8%, facilitating reliable and comprehensive asset inspections

Characterization of EMAT guided wave reflectivity on welded structures for use in ranging

Guided wave ranging measurements offers an elegant method to localize an inspection robot relative to the geometric features, such as welds, of a structure under test. This paper characterizes the suitability of various EMAT generated guided wave modes when reflecting from butt welds for the purpose of choosing a low frequency mode suitable for accurate ranging. Wave modes were tested in 10mm mild steel plate in experiment and simulation, the method of data extraction is discussed as well as the determination of the wave mode best suited for weld ranging by means of comparison of the reflection coefficients. The authors conclude SH1 at a frequency-thickness product of 2 MHz.mm, is shown to be a highly suitable wave mode for gaining a large reflection from a weld, with an average reflection co-efficient of approximately 0.45 across four different sized weld crowns. A ranging over 1 meter experimentally was demonstrated to have a 2.65% error using our method. This work will enable simultaneous detailed mapping through ranging and inspection of large welded structures by mobile robotic inspection systems using EMAT'

GADGET: A code for collisionless and gasdynamical cosmological simulations

We describe the newly written code GADGET which is suitable both for cosmological simulations of structure formation and for the simulation of interacting galaxies. GADGET evolves self-gravitating collisionless fluids with the traditional N-body approach, and a collisional gas by smoothed particle hydrodynamics. Along with the serial version of the code, we discuss a parallel version that has been designed to run on massively parallel supercomputers with distributed memory. While both versions use a tree algorithm to compute gravitational forces, the serial version of GADGET can optionally employ the special-purpose hardware GRAPE instead of the tree. Periodic boundary conditions are supported by means of an Ewald summation technique. The code uses individual and adaptive timesteps for all particles, and it combines this with a scheme for dynamic tree updates. Due to its Lagrangian nature, GADGET thus allows a very large dynamic range to be bridged, both in space and time. So far, GADGET has been successfully used to run simulations with up to 7.5e7 particles, including cosmological studies of large-scale structure formation, high-resolution simulations of the formation of clusters of galaxies, as well as workstation-sized problems of interacting galaxies. In this study, we detail the numerical algorithms employed, and show various tests of the code. We publically release both the serial and the massively parallel version of the code.Comment: 32 pages, 14 figures, replaced to match published version in New Astronomy. For download of the code, see http://www.mpa-garching.mpg.de/gadget (new version 1.1 available