71 research outputs found

    Cognitive dissonance: effects of perceived choice on attitude change

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    The hypothesis that greater perceived choice would induce attitude change as a method of cognitive dissonance reduction was investigated in a between-groups design. Twenty first and second year students at an undergraduate college were randomly assigned to one of two conditions: high-choice and no-choice. Participants in the high-choice condition were predicted to evaluate the possibility of a 10% tuition increase at an undergraduate college more favorably than participants in the no-choice condition upon writing essays in favor of a possible tuition increase. A one-way analysis of variance yielded results supporting the hypothesis that greater perceived choice induces attitude change as a method of dissonance reduction. The results are congruent with previous research on this topic

    Controllers, observers, and applications thereof

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    Controller scaling and parameterization are described. Techniques that can be improved by employing the scaling and parameterization include, but are not limited to, controller design, tuning and optimization. The scaling and parameterization methods described here apply to transfer function based controllers, including PID controllers. The parameterization methods also apply to state feedback and state observer based controllers, as well as linear active disturbance rejection (ADRC) controllers. Parameterization simplifies the use of ADRC. A discrete extended state observer (DESO) and a generalized extended state observer (GESO) are described. They improve the performance of the ESO and therefore ADRC. A tracking control algorithm is also described that improves the performance of the ADRC controller. A general algorithm is described for applying ADRC to multi-input multi-output systems. Several specific applications of the control systems and processes are disclosed

    Thermal analysis of combinatorial solid geometry models using SINDA

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    Algorithms have been developed using Monte Carlo techniques to determine the thermal network parameters necessary to perform a finite difference analysis on Combinatorial Solid Geometry (CSG) models. Orbital and laser fluxes as well as internal heat generation are modeled to facilitate satellite modeling. The results of the thermal calculations are used to model the infrared (IR) images of targets and assess target vulnerability. Sample analyses and validation are presented which demonstrate code products

    The effect of wavy leading edges on aerofoil-gust interaction noise

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    High-order accurate numerical simulations are performed to investigate the effects of wavy leading edges (WLEs) on aerofoil–gust interaction (AGI) noise. The present study is based on periodic velocity disturbances predominantly in streamwise and vertical directions that are mainly responsible for the surface pressure fluctuation of an aerofoil. In general, the present results show that WLEs lead to reduced AGI noise. It is found that the ratio of the wavy leading-edge peak-to-peak amplitude (LEA) to the longitudinal wavelength of the incident gust (?g) is the most important factor for the reduction of AGI noise. It is observed that there exists a tendency that the reduction of AGI noise increases with LEA/?g and the noise reduction is significant for LEA/?g?0.3. The present results also suggest that any two different cases with the same LEA/?g lead to a strong similarity in their profiles of noise reduction relative to the straight leading-edge case. The wavelength of wavy leading edges (LEW), however, shows minor influence on the reduction of AGI noise under the present gust profiles used. Nevertheless, the present results show that a meaningful improvement in noise reduction may be achieved when 1.0?LEW/?g?1.5. In addition, it is found that the beneficial effects of WLEs are maintained for various flow incidence angles and aerofoil thicknesses. Also, the WLEs remain effective for gust profiles containing multiple frequency components. It is discovered in this paper that WLEs result in incoherent response time to the incident gust across the span, which results in a decreased level of surface pressure fluctuations, hence a reduced level of AGI noise

    Project HyBuJET

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    A conceptual Hypersonic Business Jet (HyBuJet) was examined. The main areas of concentration include: aerodynamics, propulsion, stability and control, mission profile, and atmospheric heating. In order to optimize for cruise conditions, a waverider configuration was chosen for the high lift drag ratio and low wave drag. The leading edge and lower surface of a waverider was mapped out from a known flow field and optimized for cruising at Mach 6 and at high altitudes. The shockwave generated by a waverider remains attached along the entire leading edge, allowing for a larger compression along the lower surface. Three turbofan ramjets were chosen as the propulsion of the aircraft due to the combination of good subsonic performance along with high speed propulsive capabilities. A combination of liquid silicon convective cooling for the leading edges with a highly radiative outer skin material was chosen to reduce the atmospheric heating to acceptable level

    Trading people versus trading time: What is the difference?

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    BACKGROUND: Person trade-off (PTO) elicitations yield different values than standard utility measures, such as time trade-off (TTO) elicitations. Some people believe this difference arises because the PTO captures the importance of distributive principles other than maximizing treatment benefits. We conducted a qualitative study to determine whether people mention considerations related to distributive principles other than QALY-maximization more often in PTO elicitations than in TTO elicitations and whether this could account for the empirical differences. METHODS: 64 members of the general public were randomized to one of three different face-to-face interviews, thinking aloud as they responded to TTO and PTO elicitations. Participants responded to a TTO followed by a PTO elicitation within contexts that compared either: 1) two life-saving treatments; 2) two cure treatments; or 3) a life-saving treatment versus a cure treatment. RESULTS: When people were asked to choose between life-saving treatments, non-maximizing principles were more common with the PTO than the TTO task. Only 5% of participants considered non-maximizing principles as they responded to the TTO elicitation compared to 68% of participants who did so when responding to the PTO elicitation. Non-maximizing principles that emerged included importance of equality of life and a desire to avoid discrimination. However, these principles were less common in the other two contexts. Regardless of context, though, participants were significantly more likely to respond from a societal perspective with the PTO compared to the TTO elicitation. CONCLUSION: When lives are at stake, within the context of a PTO elicitation, people are more likely to consider non-maximizing principles, including the importance of equal access to a life-saving treatment, avoiding prejudice or discrimination, and in rare cases giving treatment priority based purely on the position of being worse-off

    Bohrsystem

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    Source: DE102013111200B3 [DE] Die Erfindung betrifft ein Bohrsystem und Bohrwerkzeug mit einem Bohrinstrument (12), welches einen Antrieb (18) aufweist, welches ein Bohrwerkzeug (14) antreibt, das eine geteilte Bohrspitze (29) umfasst, wobei das Bohrwerkzeug (14) drei oder mehr Bohrsegmente aufweist, die einen Bohrkopf (31) mit einer gemeinsamen Bohrspitze bilden, wobei jedes Bohrsegment unabhaengig von dem benachbarten Bohrsegment nach dem Pendelhubprinzip antreibbar ist sowie ein Verfahren zum Antrieb eines Bohrwerkzeuges eines solchen Bohrsystems

    Anordnung und Verfahren zum Bestücken eines Katheters mit strahlentherapeutischen Elementen

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    Beschrieben wird eine Anordnung sowie ein Verfahren zum Bestücken wenigstens einen Katheters mit strahlentherapeutischen Elementen, nachfolgend als Seeds bezeichnet, sowie mit Abstandshaltern, nachfolgend als Spacer bezeichnet, zum Zwecke einer Brachytherapie, mit einer die Seeds bevorratenden Bereitstellungseinheit, einer Reservoireinheit für die Spacer, einem Transfermechanismus zum vereinzelten, mittel- oder unmittelbaren Überführen der Seeds aus der Bereitstellungseinheit in den Katheter, einer Einbringeinheit zur vereinzelten Einführung der Spacer in den Katheter sowie einer mit dem Transfermechanismus und der Reservoireinheit in Kommunikation stehenden Steuereinheit zur kontrollierten Bestückung des Katheters mit Seeds und/oder Spacer. Die Erfindung zeichnet sich dadurch aus, dass die Bereitstellungseinheit der Seeds ein Schlittenelement umfasst, das längs einer Raumachse vermittels eines Linearantriebes bidirektional auslenkbar gelagert ist und eine Vielzahl quer zur Raumachse orientierte und in serieller Abfolge längs der Raumrichtung angeordnete, das Schlittenelement vollständig durchsetzende Durchgangsöffnungen aufweist, die jeweils zur Aufnahme eines Seeds pro Öffnung geeignet ausgebildet sind, dass die Reservoireinheit für die Spacer wenigstens eine Fördereinheit für ein Stranggut umfasst und derart seitlich neben der Raumachse angeordnet ist, so dass das Stranggut quer zur Raumachse bidirektional förderbar und zur Ein- und Durchführung in und durch jeweils eine Durchgangsöffnung innerhalb des Schlittenelementes geeignet gelagert ist, dass der Transfermechanismus das vermittels der Fördereinheit bidirektional förderbare Stranggut umfasst, dass der wenigstens eine Katheter seitlich neben der Raumachse mit einer quer zur Raumachse orientierten Katheterlängsachse derart angeordnet ist, dass eine dem Schlittenelement zugewandte Katheteröffnung koaxial zu jeweils einer Durchgangsöffnung innerhalb des Schlittenelementes ausgerichtet ist, und dass zumindest zwischen dem Schlittenelement und der Katheteröffnung eine Zerteileinheit angeordnet ist, die das Stranggut beabstandet zum Stranggutende zur Herstellung eines Spacers zerteilt
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