Cantilever micro-rheometer for the dcharacterization of sugar solutions

The volume required for the rheological characterization of fluids can be minimized by using micromechanical cantilevers as viscosity sensors. Here, a simple measurement tool for the characterization of sugar solutions is proposed. The sensor consists of a micromechanical cantilever as used in an atomic force microscopy which is integrated into a closed fluid handling system. Fluid properties are derived from an analysis of the power spectral density of the fluctuations of the cantilever deflection signal. The data acquisition system is operated with standard consumer computer components, which limits the costs for the hardware. Measurements with different sugar solutions indicate that the sensor system provides reliable viscosity values for sugar concentrations as they occur in biological systems. The viscosities of the sugar solutions could be evaluated with an error smaller than 5%

Temporal Reliability of Willingness to Pay from the National Survey of Fishing, Hunting, and Wildlife-Associated Recreation

The U.S. Fish and Wildlife Service's National Survey of Fishing, Hunting, and Wildlife Associated Recreation has been a source of information on wildlife-related recreation since 1955. The contingent valuation method has been used to estimate willingness to pay for recreation trips in the 1980, 1985, 1991, 1996 and 2001 surveys. However, relatively little comparative analysis over time has been performed. Similar value elicitation formats were used in the 1991 and 1996 surveys for bass and trout fishing, deer hunting, and nonconsumptive wildlife recreation. We statistically analyze these data to assess the temporal reliability of the willingness to pay. We control for the effects of trip quality and socioeconomic variables and find that willingness to pay is significantly lower in 1996 for each activity. A subtle, but important, change in the 1996 question format may drive the result of lower willingness to pay.

Participatory Scenario Generation: Communicating Usability Issues in Product Design through User Involvement in Scenario Generation\ud

Scenarios have proven to be a valuable tool in evaluating and communicating usability issues in consumer product design. Scenarios are explicit descriptions of hypothetical use situations. Realistic scenarios can serve as a valuable frame of reference to evaluate design solutions with regard to usability. To be able to achieve this required level of realism, involving users in scenario generation is essential. In this presentation we discuss how and where users can be involved in a scenario based product design process by means of examples of design projects that were executed by master students Industrial Design Engineering of the University of Twente. \ud \ud We distinguish direct and indirect scenario generation. In direct scenario generation the user is actively involved in a participatory scenario generation session: the scenarios are created together with users. Indirect scenario generation is an approach in which scenarios are created by designers based on common analysis techniques like observations and interviews. These scenarios are then offered to users for confirmation. Both types of user involvement in scenario generation can be aimed at either current use scenarios which describe the current situation or future use scenarios which include a new product design. \ud \ud The examples show that all strategies can be applied successfully to create realistic scenarios. Which strategy to choose depends among others upon risks and privacy issues, occurrence of infrequent events and availability of users. Furthermore, the variety of approaches shows that there is still a lot to explore with regard to benefits and limitations of the many techniques that can be applied in generating scenarios for consumer product design. We hope to contribute to this field by means of the research in our group and the work of students in the SBPD course\u

HeadOn: Real-time Reenactment of Human Portrait Videos

We propose HeadOn, the first real-time source-to-target reenactment approach for complete human portrait videos that enables transfer of torso and head motion, face expression, and eye gaze. Given a short RGB-D video of the target actor, we automatically construct a personalized geometry proxy that embeds a parametric head, eye, and kinematic torso model. A novel real-time reenactment algorithm employs this proxy to photo-realistically map the captured motion from the source actor to the target actor. On top of the coarse geometric proxy, we propose a video-based rendering technique that composites the modified target portrait video via view- and pose-dependent texturing, and creates photo-realistic imagery of the target actor under novel torso and head poses, facial expressions, and gaze directions. To this end, we propose a robust tracking of the face and torso of the source actor. We extensively evaluate our approach and show significant improvements in enabling much greater flexibility in creating realistic reenacted output videos.Comment: Video: https://www.youtube.com/watch?v=7Dg49wv2c_g Presented at Siggraph'1