Papers by Nam Anh Nguyen Hoang
Structural Control and Health Monitoring, 2009
In this study, the damping performance of various types of nonlinear dampers attached to a stay c... more In this study, the damping performance of various types of nonlinear dampers attached to a stay cable is investigated. The equivalent viscosity over one cycle of vibrations of the cable is estimated on the basis of the equivalent value of absorbed energy. Thus, an equivalent modal damping ratio is obtained that depends on the damper characteristics and damper displacement. As the mechanical design of dampers is such that their movement is usually restricted to a stroke, the average damper performance is calculated over the stroke length; the design charts available for linear dampers can be extended to nonlinear dampers as well. Results show that a nonlinear damper is effective over a wide range of vibration modes and can have potentially more design advantages than a linear damper.
Journal of Structural Engineering, 2008
The performance of a damper in controlling large-amplitude vibrations of a stay cable in a bridge... more The performance of a damper in controlling large-amplitude vibrations of a stay cable in a bridge is influenced by essential parameters such as the amount of sag and flexural rigidity of the cable, and the stiffness of the damper support. In this paper, accurate asymptotic formulas ...
Journal of Engineering Mechanics, 2007
The effects of bending on the modal properties of a stay cable with a transverse damper are analy... more The effects of bending on the modal properties of a stay cable with a transverse damper are analytically studied. Considering that the value of the flexural rigidity in the stay cable is small in practice, an explicit asymptotic formula for the modal damping of a cable with a general ...
Journal of Bridge Engineering, 2008
The combined effect of two dampers, either on the same end or opposite ends of a stay cable, is a... more The combined effect of two dampers, either on the same end or opposite ends of a stay cable, is analytically studied in this paper. By considering small distances of the dampers from the anchorages, an asymptotic formula for the modal damping ratio of the cable is derived ...
Engineering Structures, 2008
In seismic retrofit of a long-span truss bridge in Japan, a new retrofit scheme was applied in wh... more In seismic retrofit of a long-span truss bridge in Japan, a new retrofit scheme was applied in which the existing bearings of the bridge were replaced by a new floor deck isolation system. The floor decks and isolation system together can be viewed as a giant tuned ...
Earthquake Engineering & Structural Dynamics, 2005
A new method to design multiple tuned mass dampers (multiple TMDs) for minimizing excessive vibra... more A new method to design multiple tuned mass dampers (multiple TMDs) for minimizing excessive vibration of structures has been developed using a numerical optimizer. It is a very powerful method by which a large number of design variables can be e ectively handled without imposing any restriction before the analysis. Its framework is highly exible and can be easily extended to general structures with di erent combinations of loading conditions and target controlled quantities. The method has been used to design multiple TMDs for SDOF structures subjected to wide-band excitation. Some novel results have been obtained. To reduce displacement response of the structure, the optimally designed multiple TMDs have distributed natural frequencies and distinct damping ratios at low damping level. The obtained optimal conÿguration of TMDs was di erent from the earlier analytical solutions and was proved to be the most e ective. A robustness design of multiple TMDs has also been presented. Robustness is deÿned as the ability of TMDs to function properly despite the presence of uncertainties in the parameters of the system. Numerical examples of minimizing acceleration structural response have been given where the system parameters are uncertain and are modeled as independent normal variates. It was found that, in case of uncertainties in the structural properties, increasing the TMD damping ratios along with expanding the TMD frequency range make the system more robust. Meanwhile, if TMD parameters themselves are uncertain, it is necessary to design TMDs for higher damping ratios and a narrower frequency range. Copyright ? 2004 John Wiley & Sons, Ltd.
Journal of ERW and Mine Action Editorial Board reviews all articles for content and readability, ... more Journal of ERW and Mine Action Editorial Board reviews all articles for content and readability, and it reserves the right to alter articles for readability and space concerns. Every effort is made to assure accuracy and to maintain the integrity and meaning of the text. Manuscripts and photos will not be returned unless requested. The Journal Editorial Staff reserves the right to reject submissions that include text copied from other sources in part or in whole. Previously published works to which the author retains publishing rights may be submitted, but The Journal requires notification of this previous publication when authors submit material so that reprint permission may be verified. Please note that all rights to content (including photographs) published in The Journal are reserved, and notification and written approval are required before any content may be used by another source or publication. Authors who submit articles to The Journal are expected to do so in good faith and are solely responsible for the content therein, including the accuracy of all information and correct attribution for quotations and citations.
Journal of Biological Chemistry, 2018
The Journal of biological chemistry, Jan 9, 2018
During DNA replication or repair, the DNA polymerase cofactor, proliferating cell nuclear antigen... more During DNA replication or repair, the DNA polymerase cofactor, proliferating cell nuclear antigen (PCNA), homotrimerizes and encircles the replicating DNA, thereby acting as a DNA clamp that promotes DNA polymerase processivity. The formation of the PCNA trimer is also essential for targeting the replication- licensing protein, chromatin-licensing and DNA replication factor 1 (CDT1), for ubiquitin-dependent proteolysis to prevent chromosomal DNA re-replication. CDT1 uses its PCNA-interacting peptide box (PIP box) to interact with PCNA, and the CRL4 E3 ubiquitin ligase subunit CDT2 is recruited through the formation of PCNA-CDT1 complexes. However, it remains unclear how CDT1 and many other PIP box-containing proteins are marked for degradation by the CRL4CDT2 ubiquitin ligase during DNA replication or damage. Here, using recombinant protein expression coupled with site-directed mutagenesis, we report that CDT2 and PCNA directly interact and this interaction depends on the presence o...
Nature communications, Apr 24, 2018
Many non-histone proteins are lysine methylated and a novel function of this modification is to t... more Many non-histone proteins are lysine methylated and a novel function of this modification is to trigger the proteolysis of methylated proteins. Here, we report that the methylated lysine 142 of DNMT1, a major DNA methyltransferase that preserves epigenetic inheritance of DNA methylation patterns during DNA replication, is demethylated by LSD1. A novel methyl-binding protein, L3MBTL3, binds the K142-methylated DNMT1 and recruits a novel CRL4 ubiquitin ligase to degrade DNMT1. Both LSD1 and PHF20L1 act primarily in S phase to prevent DNMT1 degradation by L3MBTL3-CRL4. Mouse L3MBTL3/MBT-1 deletion causes accumulation of DNMT1 protein, increased genomic DNA methylation, and late embryonic lethality. DNMT1 contains a consensus methylation motif shared by many non-histone proteins including E2F1, a key transcription factor for S phase. We show that the methylation-dependent E2F1 degradation is also controlled by L3MBTL3-CRL4. Our studies elucidate for the first time a novel mechanism by w...
Australian Journal of Agricultural and Resource Economics, 2017
Studies of market integration show that price changes are transmitted spatially through arbitrage... more Studies of market integration show that price changes are transmitted spatially through arbitrage. Transmission across differentiated agricultural products is important to investigate, but it has not been explored given its complexities for assessment. Using data from Australian cattle markets, we examine the dynamics of Meat Standards Australia price premium transmission between states. An impulse response function analysis using Bayesian vector autoregression with sign restriction identification shows that shocks to prices and price premiums are partially transmitted contemporaneously between markets and it takes several weeks to complete transmission. In addition, we find an asymmetry of price and price premium shocks originating in Southern Queensland that have an inverse immediate impact in New South Wales, and take months to transmit the usual price response. This outcome may be explained by differences in cattle availability in each state, which can be related to forage availability due to weather conditions. Based on these results, producers can forecast fluctuations on price premiums and adjust their cattle supply accordingly.
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Papers by Nam Anh Nguyen Hoang