A method for system identification using the optimality criteria optimization approach

An algorithm similar to the optimality criteria approach used in structural optimization is presented for identifying stiffnesses of structural members by using vibration test data. A set of equivalent static inertia forces are obtained from the vibration analysis using d'Alembert's principle and are used to solve the multiple displacement constraint problem. The displacement constraint values are specified based on the measured experimental modal displacement data at critical locations. The algorithm is used to find the changes needed in the stiffnesses of the elements and the distribution of nonstructural mass of the nominal analytical model to correlate the analytical and experimental data. The algorithm alternates between the vibration analysis and static analysis to find the equivalent load vector and modify the stiffnesses. The identified stiffness properties of the structural elements can be used to control and study the dynamic response of the structure.     

Comparison of voice analysis systems for perturbation measurement

Dysphonic voices are often analyzed using automated voice analysis software. However, the reliability of acoustic measures obtained from these programs remains unknown, particularly when they are applied to pathological voices. This study compared perturbation measures from CSpeech, Computerized Speech Laboratory, SoundScope, and a hand marking voice analysis system. Sustained vowels from 29 male and 21 female speakers with mild to severe dysphonia were digitized, and fundamental frequency (F0), jitter, shimmer, and harmonics- or signal-to-noise ratios were computed. Commercially available acoustical analysis programs agreed well, but not perfectly, in their measures of F0. Measures of perturbation in the various analysis packages use different algorithms, provide results in different units, and often yield values for voices that violate the assumption of quasi-periodicity. As a result, poor rank order correlations between programs using similar measures of perturbation were noted. Because measures of aperiodicity apparently cannot be reliably applied to voices that are even mildly aperiodic, we question their utility in quantifying vocal quality, especially in pathological voices.     

An automated technique for real-time production of lifelike animations of American Sign Language

Generating sentences from a library of signs implemented through a sparse set of key frames derived from the segmental structure of a phonetic model of ASL has the advantage of flexibility and efficiency, but lacks the lifelike detail of motion capture. These difficulties are compounded when faced with real-time generation and display. This paper describes a technique for automatically adding realism without the expense of manually animating the requisite detail. The new technique layers transparently over and modifies the primary motions dictated by the segmental model and does so with very little computational cost, enabling real-time production and display. The paper also discusses avatar optimizations that can lower the rendering overhead in real-time displays.     

David Godschalk

David R. Godschalk, professor emeritus in the Department of City and Regional Planning at the University of North Carolina, Chapel Hill, passed away in early 2018. In this essay we reflect on Dave’s planning scholarship and practice. We discuss his main contributions in 4 prominent areas. First is the importance of public participation and collaboration for the planning and governance of communities. He argued for democratizing and recasting public participation, with planners working alongside community members coproducing plans and incorporating uncertainty, new information, and different viewpoints. Second is Dave’s focus on the tenets of the comprehensive plan and its core element, the land use plan. In the plan, central principles of livable urban forms and model planning processes can be integrated and translated to practice. With academic collaborators and practitioners he pioneered theoretical and empirical research on what constitutes a high-quality plan, a fundamental question at the heart of planning. Third is his research demonstrating how spatial planning can be used for hazard mitigation and urban resilience. This work forged a new generation of planning academics and practitioners who focused on hazard plans for predisaster mitigation and postdisaster recovery at multiple governmental levels. Finally, fourth is his personal involvement in planning-related institutions that he helped create, lead, or steer. In his various roles as scholar, teacher, mentor, collaborator, supervisor, planning director, and elected official, Dave touched the lives of many who now build on his contributions in creating better communities.     

Binding of harvested bacterial exopolymers to the surface of calcite

Biologically produced exopolysaccharides (EPS) affect calcite dissolution and precipitation. In this study, natural alkaliphilic microbial isolates were collected from biofilms on historic limestone. The isolates were screened for their ability to produce significant quantities of EPS in cultures. The most productive isolates were identified by 16S rRNA sequence analysis as a close relative of Bacillus cereus. EPS with different chemical structures were harvested from the isolates. Isothermal titration calorimetry (ITC) was used to quantify the thermodynamics of binding by the harvested EPS to calcite. The binding was described by a Langmuir adsorption isotherm. Characterization of the EPS showed that binding strength to calcite depended on the chemical nature of the polymer.     

BeWell: Sensing Sleep,Physical Activities and Social Interactions to Promote Wellbeing

Smartphone sensing and persuasive feedback design is enabling a new generation of wellbeing apps capable of automatically monitoring multiple aspects of physical and mental health. In this article, we present BeWell+ the next generation of the BeWell smartphone wellbeing app, which monitors user behavior along three health dimensions, namely sleep, physical activity, and social interaction. BeWell promotes improved behavioral patterns via feedback rendered as an ambient display on the smartphone’s wallpaper. With BeWell+, we introduce new mechanisms to address key limitations of the original BeWell app; specifically, (1) community adaptive wellbeing feedback, which generalizes to diverse user communities (e.g., elderly, children) by promoting better behavior yet remains realistic to the user’s lifestyle; and, (2) wellbeing adaptive energy allocation, which prioritizes monitoring fidelity and feedback responsiveness on specific health dimensions (e.g., sleep) where the user needs additional help. We evaluate BeWell+ with a 27 person, 19 day field trial. Our findings show that not only can BeWell+ operate successfully on consumer smartphones; but also users understand feedback and respond by taking steps towards leading healthier lifestyles.     

Modified fully utilized design (MFUD) method for stress and displacement constraints

The traditional fully stressed method performs satisfactorily for stress-limited structural design. When this method is extended to include displacement limitations in addition to stress constraints, it is known as the Fully Utilized Design (FUD). Typically, the FUD produces an overdesign, which is the primary limitation of this otherwise elegant method. We have modified FUD in an attempt to alleviate the limitation. This new method, called the Modified Fully Utilized Design (MFUD) method, has been tested successfully on a number of problems that were subjected to multiple loads and had both stress and displacement constraints. The solutions obtained with MFUD compare favourably with the optimum results that can be generated by using non-linear mathematical programming techniques. The MFUD method appears to have alleviated the overdesign condition and offers the simplicity of a direct, fully stressed type of design method that is distinctly different from optimization and optimality criteria formulations. The MFUD method is being developed for practicing engineers who favour traditional design methods rather than methods based on advanced calculus and non-linear mathematical programming techniques. The Integrated Force Method (IFM) was found to be the appropriate analysis tool in the development of the MFUD method. In this paper, the MFUD method and its optimality are examined along with a number of illustrative examples. © 1998 This paper was produced under the auspices of the U.S. Government and it is therefore not subject to copyright in the U.S.     

Making Room for the River

Abstract

Problem, research strategy, and findings: In this study we analyze plan integration for flood resilience in the city of Nijmegen, the site of the largest Room for the River project in The Netherlands. Little is known about the degree to which local and regional plans are coordinated with the national Room for the River program or about the cumulative influence of plans on flood vulnerability. To effectively investigate these issues, we use and build upon the Plan Integration for Resilience Scorecard (PIRS) concept and method, which analyzes the consistency and effects of networks of plans on community vulnerability. We expand the scope to include plans from multiple administrative scales and the focus to include environmental vulnerability. Using a three-phase evaluation process, we demonstrate that Room for the River policies are well integrated in Nijmegen’s network of plans, particularly with respect to flood safety and natural protection. However, we also find that policies at different administrative scales lack consistency in some places, some socially vulnerable neighborhoods receive comparatively little policy attention, and local plans often prioritize development over flood resilience, though higher tier plans sometimes make up for these policy gaps. Flood resilience is still finding its way in the Dutch planning system.

Takeaway for practice: The PIRS offers planning practitioners a method to assess how networks of plans influence community vulnerability and, as demonstrated in this analysis, to determine the degree to which plans at multiple administrative scales target the most physically, socially, and environmentally vulnerable geographic areas. It can be used to support the ambitious goals of a program like Room for the River and align them with local development priorities.