488 research outputs found

    Scenes From a Restaurant: Privacy Regulation in Stressful Situations

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    Stress results when an individual has less control over an environment or a situation than is desired. One way of regaining control and reducing stress is to regulate privacy by screening the self from spatial, visual or acoustical invasion. This study examined the use of architectural features to regulate privacy under hypothetical situations that are likely to generate low, moderate and high stress, comparing the seating choices of males and females in a variety of dining scenarios in a restaurant. In more stressful circumstances such as those associated with a job interview, participants chose restaurant seating bounded by more architectural features than they did in more relaxed dining situations such as dining with friends. Males and females appeared to be different in their responses to moderate and high stress situations. These results have implications for designers of secondary settings where stressful interactions are likely to take place

    Turning the Tables: The Psychology of Design for High-Volume Restaurants

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    The use of colors, sounds, sights, and smells can be applied to restaurant settings to encourage a high customer volume and fast table turns

    Comparison of CFD and DSMC Using Calibrated Transport Parameters

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    Hypersonic re-entry flows span a wide range of length scales where regions of both rarefied and continuum flow exist. Traditional computational fluid dynamics (CFD) techniques do not provide an accurate solution for the rarefied regions of such mixed flow fields. Although direct simulation Monte Carlo (DSMC) can be used to accurately capture both the continuum and rarefied features of mixed flow fields, they are computationally expensive when employed to simulate the low Knudsen number continuum regimes. Thus, a hybrid framework for seamlessly combining the two methodologies, CFD and DSMC, continues to be a topic of significant research effort. Ensuring consistency in the reaction kinetics and transport models employed within CFD and DSMC is a crucial requirement for obtaining a reliable solution from a hybrid framework for combined continuum/rarefied high speed flows. This paper represents one of the first studies to utilize the calibrated transport parameters developed to ensure consistency between CFD and DSMC solvers. The new variable soft sphere (VSS) parameters are compared to both previous standard variable hard sphere (VHS) parameters and also to solutions from the CFD transport properties that the new parameters were developed to reproduce

    Visual Methods: Using Photographs to Capture Customers’ Experience with Design

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    Traditional guest feedback methods such as surveys or mystery shopping are not ideal for collecting information about customers\u27 reactions to a hotel\u27s physical design. Because design is a visual medium, survey questions may not capture the whole of a guest\u27s reaction to the design. By the same token, the reaction of mystery shoppers to design is not necessarily representative of all guests. Instead, a photography-based approach allows guests to show managers and researchers what they consider to be the hotel\u27s design highlights and failures. A pilot study indicated that guests took notice of design elements that signified that the hotel was being considerate of their needs, as well as providing a functional, high-quality environment

    Detailed modeling and analysis of spacecraft plume/ionosphere interactions in low Earth orbit

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    Detailed direct simulation Monte Carlo/particle‐in‐cell simulations involving the interaction of spacecraft thruster plumes with the rarefied ambient ionosphere are presented for steady thruster firings in low Earth orbit (LEO). A nominal mass flow rate is used to prescribe the rocket exit conditions of a neutral propellant species for use in the simulations. The charge exchange interactions of the steady plume with the rarefied ionosphere are modeled using a direct simulation Monte Carlo/particle‐in‐cell methodology, allowing for a detailed assessment of nonequilibrium collisional and plasma‐related phenomena relevant for these conditions. Results are presented for both ram‐ and wake‐flow configurations, in which the thrusters are firing into (ram) or in the direction of (wake) the free stream ionosphere flow in LEO. The influence of the Earth's magnetic field on the development of the ion plume is also examined for three different field strengths: two limiting cases in which B →0 and B → ∞ , and the LEO case in which B =0.5 Gs. The magnetic field is found to have a substantial impact on the resulting neutral and ion plumes, and the gyroscopic motion of the magnetized ions results in a broadening of the ion energy distribution functions. The magnetic field model also incorporates a cross‐field diffusion mechanism which is shown to increase the current density sampled far from the thruster. Key Points Particle‐based model for plume/ionosphere interactions Charge‐exchange reactions modeled using detailed DCS/TCS data B ‐field has a strong influence on the development of plumesPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106930/1/jgra50833.pd

    Spacecraft plume interactions with the magnetosphere plasma environment in geostationary Earth orbit

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    Particle‐based kinetic simulations of steady and unsteady hydrazine chemical rocket plumes are presented in a study of plume interactions with the ambient magnetosphere in geostationary Earth orbit. The hydrazine chemical rocket plume expands into a near‐vacuum plasma environment, requiring the use of a combined direct simulation Monte Carlo/particle‐in‐cell methodology for the rarefied plasma conditions. Detailed total and differential cross sections are employed to characterize the charge exchange reactions between the neutral hydrazine plume mixture and the ambient hydrogen ions, and ion production is also modeled for photoionization processes. These ionization processes lead to an increase in local plasma density surrounding the spacecraft owing to a partial ionization of the relatively high‐density hydrazine plume. Results from the steady plume simulations indicate that the formation of the hydrazine ion plume are driven by several competing mechanisms, including (1) local depletion and (2) replenishing of ambient H+ ions by charge exchange and thermal motion of 1 keV H+ from the ambient reservoir, respectively, and (3) photoionization processes. The self‐consistent electrostatic field forces and the geostationary magnetic field have only a small influence on the dynamics of the ion plume. The unsteady plume simulations show a variation in neutral and ion plume dissipation times consistent with the variation in relative diffusion rates of the chemical species, with full H2 dissipation (below the ambient number density levels) approximately 33 s after a 2 s thruster burn.Key PointsSpacecraft hydrazine plume interacts with GEO via charge exchange and photoionization processesMagnetized hydrazine ion plumes envelop spacecraft, and neutral plumes convect downstreamIon and neutral plume dissipation times longer and species‐dependentPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135463/1/jgra52433_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135463/2/jgra52433.pd

    Development of a Detailed Surface Chemistry Framework in DSMC

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    Many of the current direct simulation Monte Carlo (DSMC) codes still employ only simple surface catalysis models. These include only basic mechanisms such as dissociation, recombination, and exchange reactions, without any provision for adsorption and finite rate kinetics. Incorporating finite rate chemistry at the surface is increasingly becoming a necessity for various applications such as high speed re-entry flows over thermal protection systems (TPS), micro-electro-mechanical systems (MEMS), surface catalysis, etc. In the recent years, relatively few works have examined finite-rate surface reaction modeling using the DSMC method.In this work, a generalized finite-rate surface chemistry framework incorporating a comprehensive list of reaction mechanisms is developed and implemented into the DSMC solver SPARTA. The various mechanisms include adsorption, desorption, Langmuir-Hinshelwood (LH), Eley-Rideal (ER), Collision Induced (CI), condensation, sublimation, etc. The approach is to stochastically model the various competing reactions occurring on a set of active sites. Both gas-surface (e.g., ER, CI) and pure-surface (e.g., LH, desorption) reaction mechanisms are incorporated. The reaction mechanisms could also be catalytic or surface altering based on the participation of the bulk-phase species (e.g., bulk carbon atoms). Marschall and MacLean developed a general formulation in which multiple phases and surface sites are used and we adopt a similar convention in the current work. Microscopic parameters of reaction probabilities (for gas-surface reactions) and frequencies (for pure-surface reactions) that are require for DSMC are computed from the surface properties and macroscopic parameters such as rate constants, sticking coefficients, etc. The energy and angular distributions of the products are decided based on the reaction type and input parameters. Thus, the user has the capability to model various surface reactions via user-specified reaction rate constants, surface properties and parameters

    Understanding Consumers’ Inferences from Price and Nonprice Information in the Online Lodging Purchase Decision

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    The sustained success of variable pricing for revenue management (RM) is dependent on the creation of appropriate price points at which to sell a given product offering. To date, few studies have considered the impact of nonprice information on consumer reaction to price, and none have investigated the relative weights that consumers assign to price and the nonprice information available to them during different phases of the purchase choice process. This exploratory study uses a combination of eye tracking and retrospective think-aloud (RTA) interviews to examine how consumers consider the price and nonprice content generated by the firm and the nonprice information generated by other consumers during two distinct phases of the online choice process: browsing and deliberation. This study’s findings suggest that during browsing, firm-generated content appears to be very influential, particularly the image selected to represent the property in search results. Both firm-generated and user-generated content play a role in hotel choice during deliberation, with the interplay among several types of information being an important indication of value for consumers

    Show Me What You See, Tell Me What You Think: Using Eye Tracking for Hospitality Research

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    Identifying precisely what consumers are looking at (and by implication what they are thinking) when they consider a web page, an image, or a hospitality environment could provide tremendous insights to the hospitality industry. By using eye tracking technology, one can almost literally see through the eyes of the customer to find out what information is examined at various points during the hotel search process or to assess which property design features attract guests’ attention. When eye tracking is immediately followed by interviews that review a graphical representation of the consumer’s eye movements, the thought processes behind consumers’ visual activity can be uncovered and explored. In this paper we explain how eye tracking works and how it could apply to hospitality research. Today’s eye tracking systems are easy for researchers to set up and use and are virtually transparent to the participant during use, making eye tracking a valuable method for examining consumer choice or facility design, or to develop employee training procedures. We argue that eye tracking would provide rich results and deserves to be considered for a wide range of hospitality applications

    Brans-Dicke cylindrical wormholes

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    Static axisymmetric thin-shell wormholes are constructed within the framework of the Brans-Dicke scalar-tensor theory of gravity. Examples of wormholes associated with vacuum and electromagnetic fields are studied. All constructions must be threaded by exotic matter, except in the case of geometries with a singularity of finite radius, associated with an electric field, which can have a throat supported by ordinary matter. These results are achieved with any of the two definitions of the flare-out condition considered.Comment: 11 pages, 3 figures; v3: corrected version, conclusions unchange
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