4,590 research outputs found
Remote Services, Inc.
The Remote Services, Inc. (RSI) case is designed as an extensible, database design and implementation project. The case is designed in two primary components: design and implementation. The design component of the case allows students to evaluate a scenario that is similar to a real-world business situation and create an appropriate design strategy. The implementation component of the case provides the students with a related scenario that gives them a completed design to be implemented. Implementation tasks include the creation of tables, loading data, creating views, creating triggers, and coding stored procedures. This allows the instructor to easily separate the design and implementation activities so that students that struggle with the design aspect of the project can start with a clean slate for the implementation activities, thus giving the instructor a better chance to assess the students\u27 implementation-oriented skills. The case can be used as a group project exercise. It can also be easily extended to include additional human resources and accounting functions for a more complex case
Studying the effects of in-vehicle information systems on driver visual behaviour – implications for design
In-vehicle information systems (IVIS) are a common feature in modern vehicles. The interaction of drivers with IVIS when driving must be considered to minimise distraction whilst maintaining the benefits provided. This research investigates the glance behaviours of drivers, assessed from video data, when using two functions – a personal navigation device (study 1) and a green driving advisory device (study 2). The main focus was to establish the number of glances of 2 seconds or more to the IVIS and relate this to driver safety (as stipulated in new guidelines for use of IVIS proposed by NHTSA). In study 1, the percentage of eyes- off-road time for drivers was much greater in the experimental (with device) condition compared to the baseline condition (14.3% compared to 6.7%) but, whilst glances to the personal navigation device accounted for the majority of the increase, there were very few which exceeded 2 seconds. Drivers in study 2 spent on average 4.3% of their time looking at the system, at an average of 0.43 seconds per glance; no glances exceeded 2 seconds. The research showed that ordinary use of IVIS (excluding manual interaction) does not lead to driver visual distraction and therefore the impact on safety is minimal. The results of the study have important design implications for future in-vehicle information systems
Chondrule Formation in Bow Shocks around Eccentric Planetary Embryos
Recent isotopic studies of Martian meteorites by Dauphas & Pourmond (2011)
have established that large (~ 3000 km radius) planetary embryos existed in the
solar nebula at the same time that chondrules - millimeter-sized igneous
inclusions found in meteorites - were forming. We model the formation of
chondrules by passage through bow shocks around such a planetary embryo on an
eccentric orbit. We numerically model the hydrodynamics of the flow, and find
that such large bodies retain an atmosphere, with Kelvin-Helmholtz
instabilities allowing mixing of this atmosphere with the gas and particles
flowing past the embryo. We calculate the trajectories of chondrules flowing
past the body, and find that they are not accreted by the protoplanet, but may
instead flow through volatiles outgassed from the planet's magma ocean. In
contrast, chondrules are accreted onto smaller planetesimals. We calculate the
thermal histories of chondrules passing through the bow shock. We find that
peak temperatures and cooling rates are consistent with the formation of the
dominant, porphyritic texture of most chondrules, assuming a modest enhancement
above the likely solar nebula average value of chondrule densities (by a factor
of 10), attributable to settling of chondrule precursors to the midplane of the
disk or turbulent concentration. We calculate the rate at which a planetary
embryo's eccentricity is damped and conclude that a single planetary embryo
scattered into an eccentric orbit can, over ~ 10e5 years, produce ~ 10e24 g of
chondrules. In principle, a small number (1-10) of eccentric planetary embryos
can melt the observed mass of chondrules in a manner consistent with all known
constraints.Comment: Accepted for publication in The Astrophysical Journa
The Prediction of Broadband Shock-Associated Noise from Dualstream and Rectangular Jets Using RANS CFD
Supersonic jets operating off-design produce broadband shock-associated noise. Broadband shock-associated noise is characterized by multiple broadband peaks in the far-field and is often the dominant source of noise towards the sideline and upstream direction relative to the jet axis. It is due to large scale coherent turbulence structures in the jet shear layers interacting with the shock cell structure. A broadband shock-associated noise model recently developed by the authors predicts this noise component from solutions to the Reynolds averaged Navier-Stokes equations using a two-equation turbulence model. The broadband shock-associated noise model is applied to dualstream and rectangular nozzles operating supersonically, heated, and off-design. The dualstream jet broadband shock-associated noise predictions are conducted for cases when the core jet is supersonic and the fan jet is subsonic, the core jet is subsonic and the fan jet is supersonic, and when both jet streams operate supersonically. Rectangular jet predictions are shown for a convergent-divergent nozzle operating both over- and under-expanded for cold and heated conditions. The original model implementation has been heavily modified to make accurate predictions for the dualstream jets. It is also argued that for over-expanded jets the oblique shock wave attached to the nozzle lip contributes little to broadband shock-associated noise. All predictions are compared with experiments
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The Internal Circadian Clock Increases Hunger and Appetite in the Evening Independent of Food Intake and Other Behaviors
Objective: Despite the extended overnight fast, paradoxically, people are typically not ravenous in the morning and breakfast is typically the smallest meal of the day. Here we assessed whether this paradox could be explained by an endogenous circadian influence on appetite with a morning trough, while controlling for sleep/wake and fasting/feeding effects. Design and Methods We studied 12 healthy non-obese adults (6 male; age, 20–42 year) throughout a 13-day laboratory protocol that balanced all behaviors, including eucaloric meals and sleep periods, evenly across the endogenous circadian cycle. Participants rated their appetite and food preferences by visual analog scales. Results: There was a large endogenous circadian rhythm in hunger, with the trough in the biological morning (8 AM) and peak in the biological evening (8 PM; peak-to-trough amplitude=17%; P=0.004). Similarly phased significant endogenous circadian rhythms were present in appetite for sweets, salty and starchy foods, fruits, meats/poultry, food overall, and for estimates of how much food participants could eat (amplitudes 14–25%; all P < 0.05). Conclusions: In people who sleep at night, the intrinsic circadian evening peak in appetite may promote larger meals before the fasting period necessitated by sleep. Furthermore, the circadian decline in hunger across the night would theoretically counteract the fasting-induced hunger increase that could otherwise disrupt sleep
Emotional Dissonance and the Information Technology Professional: A Methodological Replication Study
This study is a methodological replication of Emotional Dissonance and the Information Technology Professional by Rutner, Hardgrave, and McKnight (2008). Though we adopted the original study\u27s hypotheses and research methodology, we add to that research by investigating generational differences, increasing the sample size, and including respondents from multiple firms and industries. In this replication, we were able to 1) establish continued support for the direct impact of emotional dissonance on work exhaustion, 2) increase the explanatory power, and 3) provide broader generalizability through sampling subjects from multiple firms. We discuss both the practical and theoretical implications of these findings
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