We propose a learning-based system for enabling quadrupedal robots to manipulate large, heavy objects using their whole body. Our system is based on a hierarchical control strategy that uses the deep ...latent variable embedding which captures manipulation-relevant information from interactions, proprioception, and action history, allowing the robot to implicitly understand object properties. We evaluate our framework in both simulation and real-world scenarios. In the simulation, it achieves a success rate of 93.6<inline-formula><tex-math notation="LaTeX">\%</tex-math></inline-formula> in accurately re-positioning and re-orienting various objects within a tolerance of 0.03 <inline-formula><tex-math notation="LaTeX">\text{m}</tex-math></inline-formula> and 5<inline-formula><tex-math notation="LaTeX">^\circ</tex-math></inline-formula>. Real-world experiments demonstrate the successful manipulation of objects such as a 19.2 <inline-formula><tex-math notation="LaTeX">\text{kg}</tex-math></inline-formula> water-filled drum and a 15.3 <inline-formula><tex-math notation="LaTeX">\text{kg}</tex-math></inline-formula> plastic box filled with heavy objects while the robot weighs 27 <inline-formula><tex-math notation="LaTeX">\text{kg}</tex-math></inline-formula>. Unlike previous works that focus on manipulating small and light objects using prehensile manipulation, our framework illustrates the possibility of using quadrupeds for manipulating large and heavy objects that are ungraspable with the robot's entire body. Our method does not require explicit object modeling and offers significant computational efficiency compared to optimization-based methods.
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•Biofilm in reverse osmosis membrane regulated by quorum sensing was investigated.•Surface modification versus direct dosing of quorum sensing inhibitors was compared.•Membrane ...surface modification with QSIs shows higher inhibitory effects on biofilm.•Chemical structure of vanillin and vanillin-analogues are crucial on QS inhibition.
Quorum sensing inhibitors (QSIs) have shown promising results in reducing biofouling in various membrane systems. Vanillin was shown to inhibit QS of gram-negative bacteria during water treatment. Here, four vanillin-analogues with various chemical structures were used to understand the QS mechanisms in biofilm reduction and to compare direct dosing and surface modification of the inhibitors. Biofilm reduction, evaluated based on the content of extracellular polymeric substances (EPS), was the greatest with vanillin (49%) and occurred to some extent with 4-hydroxybenzaldehyde (21%) and m-anisaldehyde (13%), when direct dosing was applied. Experiments using vanillin-analogues revealed crucial roles of the chemical structure and functional groups on the inhibition of biofilm formation. The aldehyde and hydroxyl groups in both vanillin and 4-hydroxybenzaldehyde might be essential for QS inhibition. Further, surface modification with interfacial polymerization and immobilization of QSIs was conducted to evaluate their anti-biofouling capabilities. Surface modification was markedly effective in reducing biofilm formation; the EPS content of biofilms formed on vanillin-incorporated membranes was reduced by 64%. Additionally, the modified membranes showed a water flux comparable to that of pristine membranes, showing little possibility to block membrane pores during modification procedures. These findings will aid the development of QSI-based techniques for biofouling mitigation.
The effects of the low-temperature annealing on Zn-doped indium--tin-oxide (ITO) films such as the electrical, optical and structural properties were investigated. Zn-doped ITO films were fabricated ...by rf magnetron sputtering of ITO and Al-doped ZnO (AZO) targets on corning glass at room temperature. The content of Zn increased with increasing the power of AZO target. The carrier concentration of films shows the decreasing behaviour with increasing the content of Zn, due to a carrier compensation originating from the substitution of a doped Zn for an In or interstitial site. After the low-temperature annealing at 180 °C in vacuum, all films were slightly decreased a carrier concentration and increased the hall mobility because of the absorption of oxygen on the surface films. In addition, the average transmittance did not show a considerable change and had a high values over 80%. Especially, the Zn-doped ITO with atomic ratio of $\text{Zn}/(\text{In}+\text{Zn})$ of 6.8 at. % had the resistivity of $4\times 10^{-4}$ $\Omega$ cm, the highest hall mobility of 41 cm 2 V -1 s -1 , and the average transmittance of 82%.
Abstract
Fucoidan, a sulfated polysaccharide extracted from brown seaweed, has been proposed to effectively treat and prevent various viral infections. However, the mechanisms behind its antiviral ...activity are not completely understood. We investigate here the global transcriptional changes in bone marrow-derived dendritic cells (BMDCs) using RNA-Seq technology. Through both analysis of differentially expressed genes (DEG) and gene set enrichment analysis (GSEA), we found that fucoidan-treated BMDCs were enriched in virus-specific response pathways, including that of SARS-CoV-2, as well as pathways associated with nucleic acid-sensing receptors (RLR, TLR, NLR, STING), and type I interferon (IFN) production. We show that these transcriptome changes are driven by well-known regulators of the inflammatory response against viruses, including IRF, NF-κB, and STAT family transcription factors. Furthermore, 435 of the 950 upregulated DEGs are classified as type I IFN-stimulated genes (ISGs). Flow cytometric analysis additionally showed that fucoidan increased MHCII, CD80, and CD40 surface markers in BMDCs, indicative of greater antigen presentation and co-stimulation functionality. Our current study suggests that fucoidan transcriptionally activates PRR signaling, type I IFN production and signaling, ISGs production, and DC maturation, highlighting a potential mechanism of fucoidan-induced antiviral activity.
이 연구는 충남대학교 연구비와 교육부 조성 한국연구재단(NRF-2019R1I1A3A01060331 to J.K.) 또한, 과학기술정보통신부가 지원하는 한국연구재단(NRF)을 통한 브레인풀 프로그램(NRF-2020H1D3A2A02048437, J.G.K.)과 과학기술부(NRF-2021M3H9A1030267, S.Y.K.)의 지원으로 진행됐다.
Given a root system, the Weyl chambers in the co-weight lattice give rise to a real toric variety, called the real toric variety associated with the Weyl chambers. We compute the integral cohomology ...groups of real toric varieties associated with the Weyl chambers of type Cn and Dn, completing the computation for all classical types.
수중 구조물 형상의 영상 정보를 이용한 수중로봇 위치인식 기법 정종대(Jongdae Jung); 최수영(Suyoung Choi); 최현택(Hyun-Taek Choi) ...
Han-guk haeyang gonghak hoeji (Online),
2015, Letnik:
29, Številka:
5
Journal Article
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An autonomous underwater vehicle (AUV) can perform flexible operations even in complex underwater environments because of its autonomy. Localization is one of the key components of this autonomous ...navigation. Because the inertial navigation system of an AUV suffers from drift, observing fixed objects in an inertial reference system can enhance the localization performance. In this paper, we propose a method of AUV localization using visual measurements of underwater structures. A camera measurement model that emulates the camera's observations of underwater structures is designed in a particle filtering framework. Then, the particle weight is updated based on the extracted visual information of the underwater structures. The proposed method is validated based on the results of experiments performed in a structured basin environment.
This observational study of Medicare fee-for-service claims data evaluates demographic characteristics of psychiatrists who deliver telemental health visits in the Medicare population.
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