Toward Co-Robotic Construction: Visual Site Monitoring & Hazard Detection to Ensure Worker Safety

Construction has remained the least automated and productive as well as the most hazardous industry. Moreover, it has been plagued by a significant lack of diversity in its workforce as well as aging laborers. To address these issues, co-robotic construction has emerged as a new paradigm of construction. The industry is gradually gearing up to embrace robotic solutions, and many construction robots with various degrees of autonomy are under development or in the early stage of deployment. Presenting a different horizon of construction—harmonious co-existence and co-work between workers and robots—co-robotic construction is expected to reform labor-intensive construction into the more productive, safer, and more inclusive industry. However, an in-depth understanding of the robots’ situational intelligence is still lacking, particularly conclusive logic and technologies to ensure workers’ safety nearby autonomous (or semi-) robots, which is fundamental in realizing the co-robotic construction. To fill the gap, this research established a comprehensive robotic hazard detection roadmap and developed core technologies to realize it, leveraging unmanned aerial vehicles, computer vision, and deep learning. In this dissertation, I describe how the developed technologies with a conclusive logic can pro-actively detect the robotics hazards taking various forms and scenarios in an unstructured and dynamic construction environment. The successful implementation of the robotic hazard detection roadmap in co-robotic construction allows for timely interventions such as pro-active robot control and worker feedback, which contributes to reducing robotic accidents. Eventually, this will make human-robot co-existence and collaboration safer, while also helping to build workers’ trust in robot co-workers. Finally, the ensured safety and trust between robots and workers would contribute to promoting construction enterprises to embrace robotic solutions, boosting construction reformation toward innovative co-robotic construction.PHDCivil EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/167981/1/daeho_1.pd

Bound of Noncommutativity Parameter Based on Black Hole Entropy

We study the bound of the noncommutativity parameter in the noncommutative Schwarzschild black hole which is a solution of the noncommutative ISO(3,1) Poincare gauge group. The statistical entropy satisfying the area law in the brick wall method yields a cutoff relation which depends on the noncommutativity parameter. Requiring both the cutoff parameter and the noncommutativity parameter to be real, the noncommutativity parameter can be shown to be bounded as $\Theta > 8.4\ times 10^{-2}l_{p}$.Comment: LaTeX 7 pages, references added, minor correction

Computations of Cryogenic Cavitating Flows around Turbopump Inducer

This paper deals with the numerical computations of cryogenic cavitating flows around turbopump inducer in liquid rocket. The baseline numerical fluxes for the computations of all-speed two-phase flows (two-phase RoeM and AUSMPW+ schemes) are extended for treating general equation of states, and improved preconditioning techniques are developed for robust and efficient computations in low-speed region. As a validation step for such progress, cryogenic cavitating flows around hydrofoil and ogive are computed. Finally, numerical simulations of three-dimensional KARI turbopump inducer are carried out under various flow conditions with water and cryogenic fluids, and the difference in inducer flow physics depending on the working fluids are examined.OAIID:oai:osos.snu.ac.kr:snu2014-01/104/0000004648/19SEQ:19PERF_CD:SNU2014-01EVAL_ITEM_CD:104USER_ID:0000004648ADJUST_YN:NEMP_ID:A001138DEPT_CD:446CITE_RATE:0FILENAME:김종암_국제학술대회_20140717_김형준.pdfDEPT_NM:기계항공공학부CONFIRM:

Antioxidant, inhibition of α-glucosidase and suppression of nitric oxide production in LPS-induced murine macrophages by different fractions of Actinidia arguta stem

AbstractIn traditional systems of medicine, fruits, leaves, and stems of Actinidia arguta (Sieb. et Zucc.) Planch. ex Miq. have been used to treat various inflammatory diseases. The present study determined the proximate composition, antioxidant, anti-inflammatory, and hypoglycemic potential of A. arguta stem. Phenolic composition of hot water extract and its sub-fractions was determined by Folin–Ciocalteu’s reagent method. In vitro antioxidant activities of the samples were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging assays. Anti-inflammatory activity of different fractions was investigated through the inhibition of nitric oxide (NO) production in lipopolysaccharide (1μg/ml) stimulated RAW 264.7 cells. In addition, inhibition of α-glucosidase activity of hot water extract was determined using p-nitrophenyl-α-d-glucopyranoside (pNPG) as a substrate. Ethyl acetate (557.23mgGAE/g) fraction contains higher level of total phenolic content. The antioxidant activity evaluated by DPPH radical scavenging assay showed a strong activity for ethyl acetate (IC50 of 14.28μg/ml) and n-butanol fractions (IC50 of 48.27μg/ml). Further, ethyl acetate fraction effectively inhibited NO production in RAW 264.7 cells induced by lipopolysaccharide (LPS) than other fractions (nitrite level to 32.14μM at 200μg/ml). In addition, hot water extract of A. arguta stem exhibited appreciable inhibitory activity against α-glucosidase enzyme with IC50 of 1.71mg/ml. The obtained results have important consequence of using A. arguta stem toward the development of effective anti-inflammatory drugs

Efficient and accurate computations of all-speed cryogenic two-phase flows around turbopump inducer

The present paper deals with a numerical method for all-speed cryogenic cavitating flows in turbopump inducer. Recently, we have developed an accurate and efficient baseline numerical scheme for the computations of all-speed two-phase flows. By extending such progress, we conduct some modification of preconditioning technique and propose an accurate and efficient numerical method to deal with the computations of cryogenic two-phase flows. To verify pressure and temperature depression effect in cryogenic cavitation, we carry out numerical simulations of cryogenic cavitation flows around hydrofoil. Compared with Hords experimental data, computed results are turned out to be quite satisfactory. Finally, numerical simulations of KARI turbopump inducer are carried out under various flow conditions with water and cryogenic fluids, and we examine the differences in inducer flow physics depending on the working fluids.The authors appreciate the financial supports provided by NSL (National Space Laboratory) program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (GRANT 20120009099).OAIID:oai:osos.snu.ac.kr:snu2013-01/104/0000004648/24SEQ:24PERF_CD:SNU2013-01EVAL_ITEM_CD:104USER_ID:0000004648ADJUST_YN:NEMP_ID:A001138DEPT_CD:446CITE_RATE:0FILENAME:hj_kim.pdfDEPT_NM:기계항공공학부EMAIL:[email protected]:

Observation of superabsorption by correlated atoms

Emission and absorption of light lie at the heart of light-matter interaction. Although the emission and absorption rates are regarded as intrinsic properties of atoms and molecules, various ways to modify these rates have been sought in critical applications such as quantum information processing, metrology and light-energy harvesting. One of the promising approaches is to utilize collective behavior of emitters as in superradiance. Although superradiance has been observed in diverse systems, its conceptual counterpart in absorption has never been realized. Here, we demonstrate superabsorption, enhanced cooperative absorption, by correlated atoms of phase-matched superposition state. By implementing an opposite-phase-interference idea on a superradiant state or equivalently a time-reversal process of superradiance, we realized the superabsorption with its absorption rate much faster than that of the ordinary ground-state absorption. The number of photons completely absorbed for a given time interval was measured to be proportional to the square of the number of atoms. Our approach, breaking the limitation of the conventional absorption, can help weak-signal sensing and advance efficient light-energy harvesting as well as light-matter quantum interfaces.Comment: 7 pages, 5 figure

Computations of all-speed cryogenic cavitating flows in turbopump inducer

The present paper deals with a numerical method for all-speed cryogenic cavitating flows in turbopump inducer. Recently, we have developed an accurate and efficient baseline numerical scheme for the computations of all-speed two-phase flows. By extending such progress, we conduct some modification of preconditioning technique and propose an accurate and efficient numerical method to deal with the computations of cryogenic two-phase flows. To verify pressure and temperature depression effect in cryogenic cavitation, we carry out numerical simulations of cryogenic cavitation flows around hydrofoil. Compared with Hords experimental data, computed results are turned out to be quite satisfactory. Finally, numerical simulations of KARI turbopump inducer are carried out under various flow conditions with water and cryogenic fluids, and we examine the differences in inducer flow physics depending on the working fluids.The authors appreciate the financial supports provided by NSL (National Space Laboratory) program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (GRANT 20120009099).OAIID:oai:osos.snu.ac.kr:snu2012-01/104/0000004648/39SEQ:39PERF_CD:SNU2012-01EVAL_ITEM_CD:104USER_ID:0000004648ADJUST_YN:NEMP_ID:A001138DEPT_CD:446CITE_RATE:0FILENAME:COMPUTATIONS_OF_ALL-SPEED_CRYOGENIC_CAVITATING_FLOWS_IN_TURBOPUMP_INDUCER.pdfDEPT_NM:기계항공공학부EMAIL:[email protected]: