• Smart Structures and Systems
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• v.15 no.1
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• pp.99-117
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• 2015

The Stonecutters Bridge (SCB) in Hong Kong is the third-longest cable-stayed bridge in the world with a main span stretching 1,018 m between two 298 m high single-leg tapering composite towers. A Wind and Structural Health Monitoring System (WASHMS) is being implemented on SCB by the Highways Department of The Hong Kong SAR Government, and the SCB-WASHMS is composed of more than 1,300 sensors in 15 types. In order to establish a linkage between structural health monitoring and maintenance management, a Structural Health Rating System (SHRS) with relevant rating tools and indices is devised. On the basis of a 3D space frame finite element model (FEM) of SCB and model updating, this paper presents the development of an SHR-oriented 3D multi-scale FEM for the purpose of load-resistance analysis and damage evaluation in structural element level, including modeling, refinement and validation of the multi-scale FEM. The refined 3D structural segments at deck and towers are established in critical segment positions corresponding to maximum cable forces. The components in the critical segment region are modeled as a full 3D FEM and fitted into the 3D space frame FEM. The boundary conditions between beam and shell elements are performed conforming to equivalent stiffness, effective mass and compatibility of deformation. The 3D multi-scale FEM is verified by the in-situ measured dynamic characteristics and static response. A good agreement between the FEM and measurement results indicates that the 3D multi-scale FEM is precise and efficient for WASHMS and SHRS of SCB. In addition, stress distribution and concentration of the critical segments in the 3D multi-scale FEM under temperature loads, static wind loads and equivalent seismic loads are investigated. Stress concentration elements under equivalent seismic loads exist in the anchor zone in steel/concrete beam and the anchor plate edge in steel anchor box of the towers.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.858-863
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• 1995

The nitrogenation process and magnetic properties of $Sm_{2}Fe_{17}N_{x}\;(0{\leq}x{\leq}3)$ were investigated. During the initial nitrogenation process, the nitrogen content had linear relation with the square root of nitrogenation time, and the activation energy for the process was calculated to be 102.4 kJ/mol. The magnetic properties of $Sm_{2}Fe_{17}N_{x}$ were strongly dependent on the nitrogen content and the composition having $Sm_{2}Fe_{17}N_{2.8}$ showed optimum magnetic properties with a Curie temperature of 450 oC. The intrinsic magnetic properties of the nitride at room temperature were $M_{s}=1147\;emu/cm^{3},\;K_{1}=4.6{\times}10^{7}erg/cm^{3},\;K_{2}=6.0{\times}10^{7}erg/cm^{3}\;and\;H_{A}=290\;kOe$, respectively.

• Journal of Fisheries and Marine Sciences Education
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• v.10 no.1
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• pp.1-14
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• 1998

Transportation provides an infrastructure vital to economic growth, and it is also an integral part of production. As a port is regarded as the interface between the maritime transport and domestic transport sectors, it certainly play a key role in any economic development. Ship's delay caused by port congestion has recently has recently attracted attended with the analysis of overall operation in port. In order to analyse complicated port operation which contains large number of variable factors, queueing theory is needed to be adopted, which is applicable to a large scale transportation system in chiding ship's delay in Inchon port in relation to ship's delay problem. The overall findings are as follows ; 1. The stucture of queueing model in this port can be represented as a complex of multi-channel single-phase 2. Ship's arrival and service pattern were Poisson Input Erlangian Service. 3. The suitable formula to calculate the mean delay in this port, namely, $W_q={\frac{{\rho}}{{\lambda}(1-{\rho})}}{\frac{e{\small{N}}({\rho}{\cdot}N)}{D_{N-1}({\rho}{\cdot}N)}}$ Where, ${\lambda}$ : mean arrival rate ${\mu}$ : mean servicing rate N : number of servicing channel ${\rho}$ : utilization rate (l/Nm) $e{\small{N}}$ : the Poisson function $D_{(n-1)}$ : a function of the cumulative Poisson function 4. The utility rate is 95.0 percents in general piers, 75.39 percents in container piers, and watiting time 28.43 hours in general piers, 13.67 hours in container piers, and the length of queue is 6.17 ships in general piers, 0.93 ships in container piers, and the ship turnaround time is 107.03 hours in general piers, 51.93 hours in container piers.

• Journal of Marine Life Science
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• v.6 no.1
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• pp.1-8
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• 2021

In marine ecosystems, the biosynthesis and catabolism of dimethylsulfoniopropionate (DMSP) by marine bacteria is critical to microbial survival and the ocean food chain. Furthermore, these processes also influence sulfur recycling and climate change. Recent studies using emerging genome sequencing data and extensive bioinformatics analysis have enabled us to identify new DMSP-related genes. Currently, seven bacterial DMSP lyases (DddD, DddP, DddY, DddK, DddL, DddQ and DddW), two acrylate degrading enzymes (DddA and DddC), and four demethylases (DmdA, DmdB, DmdC, and DmdD) have been identified and characterized in diverse marine bacteria. In this review, we focus on the biochemical properties of DMSP cleavage enzymes with special attention to DddD, DddA, and DddC pathways. These three enzymes function in the production of acetyl coenzyme A (CoA) and CO₂ from DMSP. DddD is a DMSP lyase that converts DMSP to 3-hydroxypropionate with the release of dimethylsulfide. 3-Hydroxypropionate is then converted to malonate semialdehyde by DddA, an alcohol dehydrogenase. Then, DddC transforms malonate semialdehyde to acetyl-CoA and CO₂ gas. DddC is a putative methylmalonate semialdehyde dehydrogenase that requires nicotinamide adenine dinucleotide and CoA cofactors. Here we review recent insights into the structural characteristics of these enzymes and the molecular events of DMSP degradation.

• Experimental Neurobiology
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• v.26 no.5
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• pp.241-251
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• 2017

Saturation mutagenesis was performed on a single position in the voltage-sensing domain (VSD) of a genetically encoded voltage indicator (GEVI). The VSD consists of four transmembrane helixes designated S1-S4. The V220 position located near the plasma membrane/extracellular interface had previously been shown to affect the voltage range of the optical signal. Introduction of polar amino acids at this position reduced the voltage-dependent optical signal of the GEVI. Negatively charged amino acids slightly reduced the optical signal by 33 percent while positively charge amino acids at this position reduced the optical signal by 80%. Surprisingly, the range of V220D was similar to that of V220K with shifted optical responses towards negative potentials. In contrast, the V220E mutant mirrored the responses of the V220R mutation suggesting that the length of the side chain plays in role in determining the voltage range of the GEVI. Charged mutations at the 219 position all behaved similarly slightly shifting the optical response to more negative potentials. Charged mutations to the 221 position behaved erratically suggesting interactions with the plasma membrane and/or other amino acids in the VSD. Introduction of bulky amino acids at the V220 position increased the range of the optical response to include hyperpolarizing signals. Combining The V220W mutant with the R217Q mutation resulted in a probe that reduced the depolarizing signal and enhanced the hyperpolarizing signal which may lead to GEVIs that only report neuronal inhibition.

• Mycobiology
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• v.47 no.1
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• pp.59-65
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• 2019

Agrobacterium tumefaciens-mediated transformation (ATMT), as a simple and versatile method, achieves successful transformation in the yeast-like cells (YLCs) of Tremella fuciformis with lower efficiency. Establishment of a more efficient transformation system of YLCs is important for functional genomics research and biotechnological application. In this study, an enzymolysis-assisted ATMT method was developed. The degradation degree of YLCs depends on the concentration and digestion time of Lywallzyme. Lower concentration (${\leq}0.1%$) of Lywallzyme was capable of formation of limited wounds on the surface of YLCs and has less influence on their growth. In addition, there is no significant difference of YLCs growth among groups treated with 0.1% Lywallzyme for different time. The binary vector pGEH under the control of T. fuciformis glyceraldehyde-3-phosphate dehydrogenase gene (gpd) promoter was utilized to transform the enzymolytic wounded YLCs with different concentrations and digestion time. The results of PCR, Southern blot, quantitative real-time PCR (qRT-PCR) and fluorescence microscopy revealed that the T-DNA was integrated into the YLCs genome, suggesting an efficient enzymolysis-assisted ATMT method of YLCs was established. The highest transformation frequency reached 1200 transformants per $10^6$ YLCs by 0.05% (w/v) Lywallzyme digestion for 15 min, and the transformants were genetically stable. Compared with the mechanical wounding methods, enzymolytic wounding is thought to be a tender, safer and more effective method.

• Food Science of Animal Resources
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• v.41 no.4
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• pp.687-700
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• 2021

This study performed to evaluate the applicability of functional dairy food materials by comparing the calcium solubilization ability and anti-inflammatory effects of hydrolyzed casein protein. Commercial enzyme (Alcalase^®; Neutrase^®; Protamex^®; Flavourzyme^®) was added to the 10% casein solution to prepare the casein hydrolysates. Samples obtained every hour [1:200 (w/v)]. According to results of measuring the degree of hydrolysis (DH), all of four enzymatic hydrolysates increased rapidly from 30 to 40 min, and after 150 min, there were no change. Protamex^® and Neutrase^® had the highest DH compared to others enzymatic hydrolysates. After that, peptides obtained throughout a preparative liquid chromatography system. In the calcium solubility experiments, neutrase fraction (NF) 4 and NF7 showed similar activities with casein phosphopeptide (CPP). In vitro cell experiments showed that no cytotoxicity except for NF6. Also, the production of nitric oxide (NO) inhibited as the concentration of fraction samples increased. The cytokine (IL-1α, IL-6, and TNF-α) production was lower than lipopolysaccharide (+) group significantly. Therefore, the possibility of anti-inflammatory activity found in the hydrolyzed samples. According to the above experiments, NF3 and Protamex Fraction (PF) 3 selected. Amino acids selected throughout an AccQ-Tag system. As a result, 17 species of amino acids and several species of unknown amino acids identified. Both fractions had the highest content of phenylalanine. This study identified the potential of biologically active and functional peptides derived from casein that affect the food and dairy industry.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3614-3619
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• 2022

To operate the ion cyclotron resonance heating (ICRH) antennas in a better heating state and produce relatively low impurities, it is necessary to control the antenna spectrum by changing the antenna phasing. As the electrical length of the antenna feeding transmission lines is changing as a matter of the standing wave pattern at the ceramic supports, 90° elbows, T-connectors and antenna loops, we chose to measure the current at the grounding points of the antenna loops by antenna strap probe. The voltage drops along a small, several millimeter-long paths at the end of the antenna loops give a signal that is proportional to the current in the antenna loop. Through the simulation of the antenna strap probe and the actual measurement of the antenna phasing under vacuum conditions, the reliability of the antenna strap probe based diagnostic system have been successfully proved. Moreover, this system was successfully applied to the ICRH daily experiments in the spring of 2021. In the near future, the active real-time feedback control of the antenna phasing system will be developed based on this diagnostic system in the EAST tokamak.

• Geomechanics and Engineering
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• v.29 no.2
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• pp.113-131
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• 2022

A rockburst is a common disaster in deep-tunnel excavation engineering, especially for high-geostress areas. An anomalously low friction effect is one of the most important inducements of rockbursts. To elucidate the correlation between an anomalously low friction effect and a rockburst, we establish a two-dimensional prediction model that considers the discontinuous structure of a rock mass. The degree of freedom of the rotation angle is introduced, thus the motion equations of the blocks under the influence of a transient disturbing force are acquired according to the interactions of the blocks. Based on the two-dimensional discontinuous block model of deep rock mass, a rockburst prediction model is established, and the initiation process of ultra-low friction rockburst is analyzed. In addition, the intensity of a rockburst, including the location, depth, area, and velocity of ejection fragments, can be determined quantitatively using the proposed prediction model. Then, through a specific example, the effects of geomechanical parameters such as the different principal stress ratios, the material properties, a dip of principal stress on the occurrence form and range of rockburst are analyzed. The results indicate that under dynamic disturbance, stress variation on the structural surface in a deep rock mass may directly give rise to a rockburst. The formation of rockburst is characterized by three stages: the appearance of cracks that result from the tension or compression failure of the deformation block, the transformation of strain energy of rock blocks to kinetic energy, and the ejection of some of the free blocks from the surrounding rock mass. Finally, the two-dimensional rockburst prediction model is applied to the construction drainage tunnel project of Jinping II hydropower station. Through the comparison with the field measured rockburst data and UDEC simulation results, it shows that the model in this paper is in good agreement with the actual working conditions, which verifies the accuracy of the model in this paper.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.51.1-51.1
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• 2019

At the commissioning phase of KVN from 2009 to 2013, single-dish survey and monitoring observations were performed toward about 1000 evolved stars and about 60 relatively strong SiO and H2O maser sources respectively. Based on these single-dish results and VLBI feasibility test observations at K/Q/W/D bands in 2014, KVN Key Science Project (KSP) has started from 2015 and will be completed in 2019 as KSP phase I. Here we present the overview of observational studies on evolved stars using KVN. In KSP phase I, we have focused on nine KSP sources which show a successful astrometrically registered maps of SiO and H2O masers using the source frequency phase referencing method. We aim at investigating the spatial structure and dynamical effect from 43/42/86/129 GHz SiO to 22 GHz H2O maser regions associated with a stellar pulsation and development of asymmetry in circumstellar envelopes. Using the combined network KaVA (KVN+Japanese VLBI network VERA), KaVA Large Program titled on "Expanded Study on Stellar Masers: ESTEMA Phase I" was performed from 2015 to 2016. Based on ESTEMA Phase I, EAVN Large Program titled on "EAVN Synthesis of Stellar Maser Animations: ESTEMA Phase II" was also performed from 2018. The ESTEMA II project aims to publish composite animations of circumstellar H2O and SiO masers, which taken from up to 6 long-period variable stars with a variety of the pulsation periods (333-1000 days). The animations will exhibit the three-dimensional kinematics of the maser gas clumps with complexity caused by stellar pulsation-driven shock waves and anisotropy of clump ejections from the stellar surface. Adding three EAVN telescopes (Tianma 65m, Nanshan 26m and NRO 45m telescopes) with KaVA always secures the high quality of the maser image frames through the monitoring program.