Synchronization of multiple rigid body systems: a survey

The multi-agent system has been a hot topic in the past few decades owing to its lower cost, higher robustness, and higher flexibility. As a particular multi-agent system, the multiple rigid body system received a growing interest since its wide applications in transportation, aerospace, and ocean exploration. Due to the non-Euclidean configuration space of attitudes and the inherent nonlinearity of the dynamics of rigid body systems, synchronization of multiple rigid body systems is quite challenging. This paper aims to present an overview of the recent progress in synchronization of multiple rigid body systems from the view of two fundamental problems. The first problem focuses on attitude synchronization, while the second one focuses on cooperative motion control in that rotation and translation dynamics are coupled. Finally, a summary and future directions are given in the conclusion

Quantitative Attribution of Climate Effects on Hurricane Harvey’s Extreme Rainfall in Texas

Hurricane Harvey made landfall in August 2017 as the first land-falling category 4 hurricane to hit the state of Texas since Hurricane Carla in September 1961. While its intensity at landfall was notable, most of the vast devastation in the Houston metropolitan area was due to Harvey stalling near the southeast Texas coast over the next several days. Harvey\u27s long-duration rainfall event was reminiscent of extreme flooding that occurred in the neighboring state of Louisiana: both of which were caused by a stalled tropical low-pressure system producing four days of intense precipitation. A quantitative attribution analysis of Harvey\u27s rainfall was conducted using a mesoscale atmospheric model forced by constrained boundary and initial conditions that had their long-term climate trends removed. The removal of the various trends of the boundary and initial conditions minimizes the effects of warming in the air and the ocean surface on Harvey. The 60 member ensemble simulations suggest that post-1980 climate warming could have contributed to the extreme precipitation that fell on southeast Texas during 26–29 August 2017 by approximately 20%, with an interquartile range of 13%–37%. While the attribution outcome could be model dependent, this downscaling approach affords the closest means possible of a case-to-case comparison for event attribution, complementing other statistics-based attribution studies on Harvey. Further analysis of a global climate model tracking Harvey-like stalling systems indicates an increase in storm frequency and intensity over southeast Texas through the mid-21st century

Gas detection with micro and nano-engineered optical fibers

Author name used in this publication: W. JinAuthor name used in this publication: H. L. HoAuthor name used in this publication: Y. C. CaoInvited conference paper2011-2012 > Academic research: not refereed > Invited conference paperVersion of RecordPublishe

Evanescent-wave photoacoustic spectroscopy with optical micro/nano fibers

2011-2012 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Miniature fiber-tip photoacoustic spectrometer for trace gas detection

Author name used in this publication: Hoi Lut Ho2012-2013 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Future Constraints on Dark Matter with Gravitationally Lensed Fast Radio Bursts Detected by BURSTT

Understanding dark matter is one of the most urgent questions in modern physics. A very interesting candidate is primordial black holes (PBHs; Carr2016). For the mass ranges of $100 M_{\odot}$, PBHs have been ruled out. However, they are still poorly constrained in the mass ranges of $10^{-16} - 100 M_{\odot}$ (Belotsky et al. 2019). Fast radio bursts (FRBs) are millisecond flashes of radio light of unknown origin mostly from outside the Milky Way. Due to their short timescales, gravitationally lensed FRBs, which are yet to be detected, have been proposed as a useful probe for constraining the presence of PBHs in the mass window of $< 100M_{\odot}$ (Mu\~noz et al. 2016). Up to now, the most successful project in finding FRBs has been CHIME. Due to its large field of view (FoV), CHIME is detecting at least 600 FRBs since 2018. However, none of them is confirmed to be gravitationally lensed (Leung et al. 2022). Taiwan plans to build a new telescope, BURSTT dedicated to detecting FRBs. Its survey area will be 25 times greater than CHIME. BURSTT can localize all of these FRBs through very-long-baseline interferometry (VLBI). We estimate the probability to find gravitationally lensed FRBs, based on the scaled redshift distribution from the latest CHIME catalog and the lensing probability function from Mu\~noz et al. (2016). BURSTT-2048 can detect ~ 24 lensed FRBs out of ~ 1,700 FRBs per annum. With BURSTT's ability to detect nanosecond FRBs, we can constrain PBHs to form a part of dark matter down to $10^{-4}M_{\odot}$.Comment: Accepted for publication in ApJ. A summary video is available at this https://youtu.be/yivrtvuMDH

Climatic factors interference with the occurrence of Beauveria bassiana and Metarhizium anisopliae in cultivated soil

Description of method and recommendation of laboratory and field procedures for the isolation of soil borne entomopathogenic fungi (specifically Beauveria bassiana and Metarhizium anisopliae) is presented. Baiting technique method was used for screening of occurrence of indigenous populations of entomopathogenic fungi. Totally, 2068 alive greater wax moth larvae (Galleria mellonella L.) were used to trap entomopathogenic fungi present in the soil. Site selected was the experimental farm of Assiut University; only 105 larvae were infected by entomopathogenic fungi representing 5.08% mortality. B. bassiana caused 85.71% of the mortality  represented by 90 isolates. M. anisopliae caused 14.29% of the mortality giving only 15 isolates of M. anisopliae. Data showed that B. bassiana seems to be the most economically important entomopathogenic fungi inhabiting soil cultivated with wheat and cotton plants. The highest number of the isolates was recorded during spring and autumn seasons. The relationship between the incidence of B. bassiana and M. anisopliae and the selected weather factors was statistically analyzed using multiple regression analysis.Key words: Entomopathogenic fungi, Galleria mellonella, baiting technique, soil