A continued challenge for preservation is objective data to make informed collection decisions. When considering a shared national print system, this challenge relates to decisions of withdrawal or retention since catalog partners may not have data regarding the condition of others’ volumes. This conundrum led to a national research initiative funded by the Mellon Foundation, “Assessing the Physical Condition of the National Collection.” The project captured and analyzed condition data from 500 “identical” volumes from five American research libraries to explore the following: What is the condition of book collections from 1840–1940? Can condition be predicted by catalog or physical parameters? What assessment tools might indicate a book’s life expectancy? Filling gaps in knowledge about the physicality of our collections is helping identify at-risk collections and explain the cases of dissimilar “same” volumes based on the impact of paper composition. Predictive modeling and assessment tools are also used to improve the understanding of what is typical for specific eras.
A drone-projector equipped with a beam projector mounted on a drone has been investigated in order to develop a projector which can overcome restriction of place on which an image is projected. For the stability, the drone-projector requires its mass to be centered, and the additional weights related to projector should be within the payload of the drone. In addition to this requirement, the drone-projector should be designed to minimize the distortion of image caused by 3D translations or rotations of a drone during its hovering due to vibration of propellers, or global positioning system (GPS) errors. In this paper, we consider rotation of a droneprojector which makes the projected image tilted, keystoned, and shifted. To overcome this problem, we propose a software-based stabilization method which pre-corrects the image to be projected based on flight information. Our experimental results show that the distortion of the projected image due to rotations of the proposed drone-projector is attenuated by applying our stabilization method.