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  1. Free, publicly-accessible full text available September 1, 2022
  2. Ishigami, G ; Yoshida, K (Ed.)
    The ability to build structures with autonomous robots using only found, minimally processed stones would be immensely useful, especially in remote areas. Assembly planning for dry-stacked structures, however, is difficult since both the state and action spaces are continuous, and stability is strongly affected by complex friction and contact constraints. We propose a planning algorithm for such assemblies that uses a physics simulator to find a small set of feasible poses and then evaluates them using a hierarchical filter. We carefully designed the heuristics for the filters to match our goal of building stable, free-standing walls. These plans are thenmore »executed open-loop with a robotic arm equipped with a wrist RGB-D camera. Experimental results show that the proposed planning algorithm can significantly improve the state of the art in robotic dry stacking.« less
  3. Fluorescent portable monitoring systems provide real-time and on-site analysis of a sample solution, avoiding transportation delays and solution degradation. However, some applications, such as environmental monitoring of bodies of water with algae pollution, rely on the temperature control that off-site systems provide for adequate solution results. The goal of this research is the development of a temperature stabilization module for a portable fluorescent sensing platform, which is necessary to prevent inaccurate results. Using a Peltier device-based system, the module heats/cools a solution through digital-to-analog control of the current, using three surface-mounted temperature modules attached to a copper cuvette holder, whichmore »is directly attached to the Peltier device. This system utilizes an in-house algorithm for control, which effectively minimizes temperature overshooting when a change is enacted. Finally, with the use of a sample fluorescent dye, Rhodamine B, the system's controllability is highlighted through the monitoring of Rhodamine B's fluorescence emission decrease as the solution temperature increases.« less
  4. Ionic liquid based fiber welding has been used to attach the metal−organic framework (MOF) UiO-66-NH2to cotton fibers. The results show that by controlling the extent of the welding process, it is possible to produce fibers that contain a high surface area (approximately 50−100 m2/ g), an X-ray diffraction pattern consistent with UiO-66-NH2, and fibers that are chemically reactive to dimethyl 4-nitrophenyl phosphate (DMNP), a common chemical weapon simulant. The ionic liquid/MOF welding solution can be applied by directly placing the fabric in the welding solution or by utilizing an airbrushing technique. Both welding techniques are shown to be scalable withmore »results collected on approximately 1×1, 5 ×5, and 15.5×15.5 in. swatches. The results are also applicable to weaving methods where the MOF is welded to individual threads and subsequently woven into a textile. The results provide an industrially scalable method of attaching a wide variety of MOFs to cotton textiles, which does not require synthesizing the MOF in the presence of the textile.« less
  5. Heating, ventilation and air-conditioning (HVAC) systems have been adopted to create comfortable, healthy and safe indoor environments. In the control loop, the technical feature of the human demand-oriented supply can help operate HVAC effectively. Among many technical options, real time monitoring based on feedback signals from end users has been frequently reported as a critical technology to confirm optimizing building performance. Recent studies have incorporated human thermal physiologysignals and thermal comfort/discomfort status as real-time feedback signals. A series of human subject experiments used to be conducted by primarily adopting subjective questionnaire surveys in a lab-setting study, which is limited inmore »the application for reality. With the help of advanced technologies, physiological signals have been detected, measured and processed by using multiple technical formats, such as wearable sensors. Nevertheless, they mostly require physical contacts with the skin surface in spite of the small physical dimension and compatibility with other wearable accessories, such as goggles, and intelligent bracelets. Most recently, a low cost small infrared camera has been adopted for monitoring human facial images, which could detect the facial skin temperature and blood perfusion in a contactless way. Also, according to latest pilot studies, a conventional digital camera can generate infrared images with the help of new methods, such as the Euler video magnification technology. Human thermal comfort/discomfort poses can also be detected by video methods without contacting human bodies and be analyzed by the skeleton keypoints model. In this review, new sensing technologies were summarized, their cons and pros were discussed, and extended applications for the demand-oriented ventilation were also reviewed as potential development and applications.« less
  6. Research about diversity in Construction and Civil Engineering (CCE) has been conducted from both the academic and industrial points of view. Researchers have suggested several strategies to further attract women and ethnic minorities (WEMs) to CCE at both academic and industry levels, mainly due to the skilled labor shortage, as well as to preserve the future success of the U.S. economy. Accordingly, this literature review aims to present the current levels of diversity and inclusion of minorities in CCE at academic and industry levels, while it identifies effective strategies for increasing diversity, recognizes knowledge gaps, and suggests recommendations for futuremore »research. The review is conducted by searching relevant papers from leading construction management and engineering education peer-reviewed publications. The findings indicate that although the low participation of minorities in CCE industries and education has been studied a few times from a gender point of view, it has not received adequate attention from the ethnicity perspective, especially at the academic level. This paper contributes to the body of knowledge by bringing together information related to the underrepresentation of WEMs in CCE academia and workforce environments and identifying the potential reasons for this low participation.« less