Risk Degree of Ship-bridge Collision based on Theory of Ship Collision Avoidance

Yihua Liu,Yingjie Xiao 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.11

Bridges have played an integral role in the development of economy and progress of human society, which facilitate transportation and promote regional economic development. However, a large number of bridges for sea-crossing or river-crossing have impeded the water transportation to varying degrees, and then one part of bridges are confronted with higher risk of ship-bridge collision. There are many ship-bridge collision accidents in the world in recent decades, which caused huge casualties and property losses. This paper proposes the model of risk degree for ship-bridge collision based on the theory of ship collision avoidance, as one parts of the system of active warning of ship-bridge collision avoidance, which can show the index of dynamic risk degree for vessels passing through bridge area. The index of ship-bridge collision can make more efficiency for the system of active warning of ship-bridge collision avoidance, which can ensure safety for vessels and bridges. The verification results show the application possibility of the model in practice.

EFFECT OF Cu ATOMIC SEGREGATION ON THE FROZEN STRUCTURES OF Co–Cu BIMETALLIC CLUSTERS

YINGJIE ZHANG,YONGQIANG LI,XUYANG XIAO,YUNHUI YAN 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2012 NANO Vol.7 No.6

Atomic segregation in bimetallic clusters can in°uence the surface constituent and be used to a®ect the frozen structure. In this study, molecular dynamics simulation with an embedded atom method was used to study the frozen structures of (CoCu)561 clusters with di®erent Co contents. It is found that the clusters can freeze to form icosahedron, truncated octahedron, decahedron or hcp with the change of Co contents. In these geometries, the structure of the lowest energy state is hcp, then in turn decahedron and truncated octahedron. The frozen structures are related to the release of excess energy, while the released excess energy was a®ected by the amount of segregated Cu atoms. This means that the atomic segregation can be used to tune the structures of bimetallic clusters.

A detailed study of physicochemical properties and microstructure of EmimCl-EG deep eutectic solvents: Their influence on SO2 absorption behavior

Jiahong Zhu,Yingjie Xu,Xiao Feng,Xiao Zhu 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.67 No.-

To get a better understanding of the effect of physicochemical properties and microstructure on SO2 absorption behavior of DESs with different molar ratios of EmimCl and EG (from 2:1 to 1:2), densities (ρ), viscosities (η), speeds of sound (u), refractive indices (nD), and thermal decomposition temperatures (Td) of EmimCl-EG DESs were measured and used to obtain the other derived properties, such as thermal expansion coefficient (αp) and activation energy for viscous flow (Eη). Moreover, FT-IR spectra and in situ variable-temperature NMR spectroscopy were employed to study the microstructures of DESs. Based on physicochemical and spectroscopic properties, the influence of the concentrations of EmimCl on the interactions in DESs was explored to be associated with their SO2 absorption behavior. The results show that the interactions between Emim+ and Cl− of EmimCl is gradually weakening with increasing the concentration of EG in DESs by forming of hydrogen bond interaction of OH⋯Cl−, resulting in a decrease of ρ, η, u, nD, and Td of DESs, and hindering the charge–transfer interaction of SO2 with Cl− and deceasing SO2 capture capacity. Moreover, the SO2 absorption capacity of DESs is proportional to their ρ and Eη, respectively.

SVPWM algorithm for five-level active-neutral-point-clamped H-bridge inverters

Jiang, Linfei,Xiao, Fei,Hu, Liangdeng,Jia, Yingjie The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.8

When compared with the three-level H-bridge inverter, the five-level active-neutral-point-clamped (5L-ANPC) H-bridge inverter has high output voltage level, high output power, and lower current harmonic content. Thus, it has the potential to be applied to the vessel integrated power systems. This paper proposes a method of space vector pulse width modulation (SVPWM) for the 5L-ANPC H-bridge inverter. First, the selection of the available switching vectors is based on an analysis of the switching constraints, switching times, and common-mode voltage. Then, according to the control requirements of the neutral-point potential and the floating capacitor voltage of the inverter, the action time of each switching vector is calculated. The sequence of the switching vectors in different intervals is determined based on the principle of reducing the switching times. Finally, a hardware-in-loop (HIL) real-time simulation experimental platform is established to verify the proposed method.

Double-Spiral Hexagonal Boron Nitride and Shear Strained Coalescence Boundary

Park, Hyo Ju,Tay, Roland Yingjie,Wang, Xiao,Zhao, Wen,Kim, Jung Hwa,Ruoff, Rodney S.,Ding, Feng,Teo, Edwin Hang Tong,Lee, Zonghoon American Chemical Society 2019 NANO LETTERS Vol.19 No.7

<P>Among the different growth mechanisms for two-dimensional (2D) hexagonal boron nitride (h-BN) synthesized using chemical vapor deposition, spiraling growth of h-BN has not been reported. Here we report the formation of intertwined double-spiral few-layer h-BN that is driven by screw dislocations located at the antiphase boundaries of monolayer domains. The microstructure and stacking configurations were studied using a combination of dark-field and atomic resolution transmission electron microscopy. Distinct from other 2D materials with single-spiral structures, the double-spiral structure enables the intertwined h-BN layers to preserve the most stable AA′ stacking configuration. We also found that the occurrence of shear strains at the boundaries of merged spiral islands is dependent on the propagation directions of encountering screw dislocations and presented the strained features by density functional theory calculations and atomic image simulations. This study unveils the double-spiral growth of 2D h-BN multilayers and the creation of a shear strain band at the coalescence boundary of two h-BN spiral clusters.</P> [FIG OMISSION]</BR>

Performance of different absorber materials and move-in/out strategies for the control rod in small rod-controlled pressurized water reactor: A study based on KLT-40 model

Wu Zhiqiang,Xie Jinsen,Chen Pengyu,Xiao Yingjie,Ni Zining,Liu Tao,Deng Nianbiao,Sun Aikou,Yu Tao 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.7

Small rod-controlled pressurized water reactors (PWR) are the ideal energy source for vessel propulsion, benefiting from their high reactivity control efficiency. Since the control rods (CRs) increase the complexity of reactivity control, this paper seeks to study the performance of CRs in small rod-controlled PWRs to extend the lifetime and reduce power offset due to CRs. This study investigates CR grouping, move-in/out strategies, and axially non-uniform design effects on core neutron physics metrics. These metrics include axial offset (AO), core lifetime (CL), fuel utilization (FU), and radial power peaking factor (R-PPF). To simulate the movement of the CRs, a "Critical-CR-burnup" function was developed in OpenMC. In CR designs, the CRs are grouped into three banks to study the simultaneous and prioritized move-in/out strategies. The results show CL extension from 590 effective full power days (EFPDs) to 638–698 EFPDs. A lower-worth prioritized strategy minimizes AO and the extremum values decrease from 0.69 and + 0.81 to 0.28 and + 0.51. Although an axially non-uniform CR design can improve AO at the beginning of cycle (BOC), considering the overall CR worth change is crucial, as a significant decrease can adversely impact axial power distribution during the middle of cycle (MOC).

Application of the sheet electrode to enhance the geometric characteristics of micro-holes fabricated by electrochemical discharge machining

Zhongning Guo,Shunzhi Qiao,Liangliang Wang,Kai Zhang,Yingjie Xiao,Zhixiang Zou 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.11

The electrochemical discharge machining (ECDM) is an advanced machining technology used to fabricate micro-holes in glass. In this study, a sheet tool electrode is employed to increase electrolyte circulation in machining zone. The effect of pulse voltage, frequency, duty cycle, electrolyte concentration, and tool rotation speed on the geometric properties of micro-holes were evaluated. The results showed that when using a sheet tool electrode, the machining depth increased by 42.9 %, and the machining efficiency increased by 51.1 %, while the entrance diameter was reduced by 13.9 % than cylindrical tool electrode. Additionally, the heat-affected zone (HAZ) and entrance hole surface quality is improved. On the other hand, the Taguchi method was employed to analyze the relative importance of the machining parameters on geometric characteristics of micro-holes (i.e. drilled depth and entrance diameter of micro-holes). Finally, the entrance hole overcut of 148 μm was successfully fabricated with a depth of 2520 μm. It was discovered that using a sheet tool electrode is a simple method for machining a deep micro-hole with high machining efficiency and a range entrance hole diameter overcut that is acceptable.