Searching and fixating: scale-invariance vs. characteristic timescales in attentional processes

In an experiment involving semantic search, the visual movements of sample populations subjected to visual and aural input were tracked in a taskless paradigm. The probability distributions of saccades and fixations were obtained and analyzed. Scale-invariance was observed in the saccadic distributions, while the fixation distributions revealed the presence of a characteristic (attentional) time scale for literate subjects. A detailed analysis of our results suggests that saccadic eye motions are an example of Levy, rather than Brownian, dynamics.Comment: Accepted to Europhysics Letters (2011

Uncertainty in the performance validation of HVAC Systems

A first principles based model approach to AHU cooling coil performance validation is presented. The model of correct operation is compared to that observed in the real system. In the scheme, uncertainty in the measurements and the models is evaluated to generate robust thresholds for decision making. The approach describes the design intent by estimating certain model parameters from design data and expert knowledge. The method systematically incorporates the uncertainty in these parameter estimates in the calculation of the system validation threshold. This yields a definite, transparent indication of system performance to a stated level of confidence. The approach is demonstrated on a cooling coil subsystem installed in an air-handling unit serving zones in a real building

Ground water supplies in northern Cook and northern DuPage counties

At head of title: State of Illinois...Enumeration continues from preceding title

The disposal of the sewage of the Sanitary district of Chicago

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Sandstone water supplies of the Joliet area

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In Search of America: One Barbershop at a Time

Barbershops are a mainstay of the American tradition and have served as an anchor to main streets across the country. They have a colorful history and play an important role as community gathering places for men and boys. Before our society became more mobile, a boy may have grown up in the same barbershop, in the same barber chair, getting his hair cut by the same barber, from his years as a toddler, a teenager, and into his young adulthood. Many old school barbers have cut the hair of multiple generations, grandfathers, fathers, and sons, while standing in the same four foot by four foot space for over forty, fifty, sixty, or even seventy years. This thesis explores the various roles and many contributions of local barbershops from personal observation and business travels across America combined with scholarly and popular literature

Production of fuel gas by anaerobic fermentations

Reprint. Originally published: Industrial and engineering chemistry ; v. 22 (November 1930)Includes bibliographical references

Preliminary data on surface water resources

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Ground water supplies of the Chicago-Joliet-Chicago Heights area

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Anaerobic fermentations

At head of title: State of Illinois. Department of registration and education. Division of the state water supply. A.M. Buswell, chief. W.D. Hatfield, editor.Bibliography: p. 186-193.Enumeration continues from preceding title