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  1. Free, publicly-accessible full text available October 2, 2024
  2. Turkan, Y. and (Ed.)
    Advances in construction robotics represent a potential shift in building design and construction. In general, construction robotics are usually deployed directly onto construction sites without systematically evaluating the design constructability for robotic applications. Literature on constructability suggest that ignoring it during design will cause rework, inefficiency, and higher cost. Although previous studies have widely discussed design constructability, they mainly focus on traditional human craft-based construction methods. Whereas a gap still exists in design constructability assessment for construction robotics. This paper presents an initial analytical framework for constructability assessment for construction robotics during the design phase. Specifically, we summarize factors that impact robotic constructability based on robotic features, design features, work constraints, and piloted an automated constructability checking system for robotics. Additionally, this study takes CANVAS, a drywall finishing robot, as case study to create a framework in simulation environment and the results demonstrate the potential value of the proposed framework. 
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    Free, publicly-accessible full text available June 28, 2024
  3. Desjardin, S. and (Ed.)
    The development of robotics in the Architecture, Engineering, and Construction (AEC) industry has emerged in recent years in response to technology advances and industry challenges such as workforce shortages. Construction robotics has the potential to increase construction productivity and accuracy as well as reduce accidents and costs. However, their introduction to construction sites creates new challenges. Previous studies have shown that robots can cause major changes in construction workflow, scope, and methods. Construction robotics introduce key changes to the work process and the sequence of construction tasks. The traditional planning approach for work break down structure and scheduling assigns resources for construction activities based on human labor and craft methods. Despite this, the capabilities of robotics relative to construction resource planning, sequencing, and work scope has not been fully studied. To address this, the implementation of robotics in construction projects needs a new approach to organizing work packages (WP). With the inclusion of robotics as a resource, planning parameters such as methods and sequence will change both the scope and accordingly the work packaging for construction. This paper aims to systematically identify the potential impacts of robots on construction processes, as well as how those changes influences work packaging. The methodology is based on data integration and content analysis from literature review and collected interviews with project participants about real-world construction projects. The paper discusses how construction robots impact the work package approach and categorizes the affected factors. These factors include the work area, sequence and priority of construction activities, safety management, allocation of risk responsibility for tasks, interaction with other trades, and required materials. 
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    Free, publicly-accessible full text available May 26, 2024
  4. Using transdimensional plasmonic materials (TDPM) within the framework of fluctuational electrodynamics, we demonstrate nonlocality in dielectric response alters near-field heat transfer at gap sizes on the order of hundreds of nanometers. Our theoretical study reveals that, opposite to the local model prediction, propagating waves can transport energy through the TDPM. However, energy transport by polaritons at shorter separations is reduced due to the metallic response of TDPM stronger than that predicted by the local model. Our experiments conducted for a configuration with a silica sphere and a doped silicon plate coated with an ultrathin layer of platinum as the TDPM show good agreement with the nonlocal near-field radiation theory. Our experimental work in conjunction with the nonlocal theory has important implications in thermophotovoltaic energy conversion, thermal management applications with metal coatings, and quantum-optical structures. 
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    Free, publicly-accessible full text available August 1, 2024
  5. Transfer learning on graphs drawn from varied distributions (domains) is in great demand across many applications. Emerging methods attempt to learn domain-invariant representations using graph neural networks (GNNs), yet the empirical performances vary and the theoretical foundation is limited. This paper aims at designing theory-grounded algorithms for graph domain adaptation (GDA). (i) As the first attempt, we derive a model-based GDA bound closely related to two GNN spectral properties: spectral smoothness (SS) and maximum frequency response (MFR). This is achieved by cross-pollinating between the OT-based (optimal transport) DA and graph filter theories. (ii) Inspired by the theoretical results, we propose algorithms regularizing spectral properties of SS and MFR to improve GNN transferability. We further extend the GDA theory into the more challenging scenario of conditional shift, where spectral regularization still applies. (iii) More importantly, our analyses of the theory reveal which regularization would improve performance of what transfer learning scenario, (iv) with numerical agreement with extensive real-world experiments: SS and MFR regularizations bring more benefits to the scenarios of node transfer and link transfer, respectively. In a nutshell, our study paves the way toward explicitly constructing and training GNNs that can capture more transferable representations across graph domains. Codes are released at 
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    Free, publicly-accessible full text available February 1, 2024
  6. Free, publicly-accessible full text available March 1, 2024
  7. Free, publicly-accessible full text available March 1, 2024

    We study the optical variability of a sample of candidate low-mass (dwarf and Seyfert) active galactic nuclei (AGNs) using Zwicky Transient Facility g-band light curves. Our sample is compiled from broad-line AGNs in dwarf galaxies reported in the literature with single-epoch virial black hole (BH) masses in the range MBH ∼ 104–108 M⊙. We measure the characteristic ‘damping’ time-scale of the optical variability τDRW, beyond which the power spectral density flattens, of a final sample of 79 candidate low-mass AGNs with high-quality light curves. Our results provide further confirmation of the MBH–τDRW relation from previous work within 1σ agreement, adding 78 new low-mass AGNs to the relation. The agreement suggests that the virial BH mass estimates for these AGNs are generally reasonable. We expect that the optical light curve of an accreting intermediate-mass black hole (IMBH) to vary with a rest-frame damping time-scale of ∼tens of hours, which could enable detection and direct mass estimation of accreting IMBHs in wide-field time-domain imaging surveys with sufficient cadence like with the Vera C. Rubin Observatory.

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  9. Free, publicly-accessible full text available January 1, 2024
  10. Free, publicly-accessible full text available January 1, 2024