Rupture propagation and arrest during 2016 Gyeongju earthquake sequence

Xiangyi An,Jin-Han Ree,Sungshil Kim,Dabin Heo,Kyungjoon Cho,Tae-Seob Kang,Kwang-Hee Kim,YoungHee Kim,Junkee Rhie 대한지질학회 2022 대한지질학회 학술대회 Vol.2022 No.10

Evaluating LIMU System Quality with Interval Evidence and Input Uncertainty

Xiangyi Zhou,Zhi-Jie Zhou,Xiaoxia Han,Zhichao Ming,Yanshan Bian 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.11

The laser inertial measurement unit is a precision device widely used in rocket navigation system and other equipment, and its quality is directly related to navigation accuracy. In the quality evaluation of laser inertial measurement unit, there is inevitably uncertainty in the index input information. First, the input numerical information is in interval form. Second, the index input grade and the quality evaluation result grade are given according to different national standards. So, it is a key step to transform the interval information input by the index into the data form consistent with the evaluation result grade. In the case of uncertain input, this paper puts forward a method based on probability distribution to solve the problem of asymmetry between the reference grade given by the index and the evaluation result grade when evaluating the quality of laser inertial measurement unit. By mapping the numerical relationship between the designated reference level and the evaluation reference level of the index information under different distributions, the index evidence symmetrical with the evaluation reference level is given. After the uncertain input information is transformed into evidence of interval degree distribution by this method, the information fusion of interval degree distribution evidence is carried out by interval evidential reasoning algorithm, and the evaluation result is obtained by projection covariance matrix adaptive evolution strategy optimization. Taking a five-meter redundant laser inertial measurement unit as an example, the applicability and effectiveness of this method are verified.

Analysis of notch depth and loading rate effects on crack growth in concrete by FE and DIC

Xiangyi Zhu,Xudong Chen,Jun Lu,Xiangqian Fan 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.24 No.6

In this paper, the fracture characteristics of concrete specimens with different notch depths under three-point flexural loads are studied by finite element and fracture mechanics methods. Firstly, the concrete beams (the size is 700×100×150 mm) with different notch depths (a=30 mm, 45 mm, 60 mm and 75 mm respectively) are tested to study the influence of notch depths on the mechanical properties of concrete. Subsequently, the concrete beams with notch depth of 60 mm are loaded at different loading rates to study the influence of loading rates on the fracture characteristics, and digital image correlation (DIC) is used to monitor the strain nephogram at different loading rates. The test results show that the flexural characteristics of the beams are influenced by notch depths, and the bearing capacity and ductility of the concrete decrease with the increase of notch depths. Moreover, the peak load of concrete beam gradually increases with the increase of loading rate. Then, the fracture energy of the beams is accurately calculated by tail-modeling method and the bilinear softening constitutive model of fracture behavior is determined by using the modified fracture energy. Finally, the bilinear softening constitutive function is embedded into the finite element (FE) model for numerical simulation. Through the comparison of the test results and finite element analysis, the bilinear softening model determined by the tail-modeling method can be used to predict the fracture behavior of concrete beams under different notch depths and loading rates.

Mechanical properties of pervious concrete with recycled aggregate

Xiangyi Zhu,Xudong Chen,Nan Shen,Huaxuan Tian,Xiangqian Fan,Jun Lu 사단법인 한국계산역학회 2018 Computers and Concrete, An International Journal Vol.21 No.6

In order to research the influence of different recycled aggregate contents on the mechanical properties of pervious concrete, the experimental study and numerical simulation analysis of the mechanical properties of pervious concrete with five kinds of recycled aggregates contents (0%, 25%, 50%, 75% and 100%) are carried out in this paper. The experimental test were first performed on concrete specimens of different sizes in order to determine the influence of recycled aggregate on the compressive strength and splitting tensile strength, direct tension strength and bending strength. Then, the development of the internal cracks of pervious concrete under different working conditions is studied more intuitively by PFC3D. The experimental results show that the concrete compressive strength, tensile strength and bending strength decrease with the increase of the recycled aggregate contents. This trend of reduction is not only related to the brittleness of recycled aggregate concrete, but also to the weak viscosity of recycled aggregate and cement paste. It is found that the fracture surface of pervious concrete with recycled aggregate is smoother than that of natural aggregate pervious concrete by PFC3D, which means that the bridging effect is weakened in the stress transfer between the left and right sides of the crack. Through the analysis of the development of the internal cracks, the recycled aggregate concrete generated more cracks than the natural aggregate concrete, which means that the recycled aggregate concrete is easier to form a coalescence fracture surface and eventually break.

Mn0.05Cd0.95S/Cu2SeI p-n heterojunction with high-conductivity for efficient photocatalytic hydrogen evolution

Xiangyi Wang,Zhiliang Jin 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.103 No.-

It is undoubtedly that constructing heterojunction on the surface of semiconductor materials is an effectiveway to improve the performance of photocatalysts. Here, Cu2SeI nanospheres were dispersed on thesurface of Mn0.05Cd0.95S nanoparticles constructed a p-n heterojunction photocatalyst with high conductivity. Firstly, SEM and TEM showed that the load of Cu2SeI nanospheres successfully formed a close contacton the surface of MCS, which was conducive to the rapid charge transfer between the two. Undervisible light irradiation, Na2S/Na2SO3 (0.35 M/0.25 M) was used as sacrifice reagent for hydrogen production. The results showed that the construction of p-n heterojunction was beneficial to charge transfer andthe hydrogen evolution ability of the composite catalyst was greatly improve, the 3%MCS/Cu2SeI showedthe best hydrogen production activity reaching 677.4 lmol after 5 h, it is 12.3 times higher than that ofsingle catalyst MCS, In addition, the results of X-ray photoelectron spectroscopy (XPS) show that thebinding energies of the elements in the composite catalysts are different compared with those in the catalystsalone, indicating that there is a interaction between the catalysts. Through the analysis of photoelectrochemicaland fluorescence spectra, the charge transfer kinetics of the composite catalyst wasexplained and discussed in depth. On the basis of the above analysis results, the possible photocatalyticreaction mechanism of the composite catalyst was proposed, and the mechanism was analyzed and discussed. This work has undoubtedly made a further improvement for the activity of photocatalytic hydrogenproduction.

구마모토지진 이전과 지진 당시 규슈의 지표변형

안상익(Xiangyi An),김성실(Sungshil Kim),이진한(Jinhan Ree) 대한지질학회 2018 대한지질학회 학술대회 Vol.2018 No.10

Research on Fire Extinguishing Shell Material Selection and Parameters Optimization

Guan Xiangyi,Liu Shaogang,Sun Qingli,Ma Bingpeng,Zhao Lili 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.5

Remote grenade is often used to fight. Fire extinguishing shell material selection and structure parameters have a great influence on fire extinguishing dispersion and even directly determine the extinguishing effect. Taking the crown fire of Mongolica 20 years old as example, the influences of fire extinguishing bombs with different shell materials on fire extinguishing dispersion are compared in this paper. Simulation of fire extinguishing bombs with different shell materials is operated by finite elements software and come to a conclusion that unidirectional short fiber reinforced composite materials is suitable for fire extinguishing bomb shell because of less power consumption and longer dispersion distance when shell bursting. In the meantime, the experiment is carried out on the sample of fire extinguishing bomb with the shell of unidirectional short fibers. The conclusion is length-diameter ratio to put plant crown fire out has better fire control effect than fire extinguishing bomb with 1.5% powder and save the use of extinguishant.

GNSS자료를 이용한 지진발생대의 인지: 일본 규수의 예

안상익(Xiangyi An),이진한(Jinhan Ree),김성실(Sungshil Kim),김준석(Junseok Kim) 대한지질학회 2019 대한지질학회 학술대회 Vol.2019 No.10

Border Detecting Method for IR Image of Fire Extinguishing Agent Dispersion

Guan xiangyi,Liu shaogang,Ma bingpeng,Sun zhenbao,Zhao lili,Xu ying 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.4

Reflections on Difficulties and Solutions of English Teaching in China

Zheng Xiangyi(쩡시앙이) 국제지역연구학회 2010 국제지역학논총 Vol.3 No.2

중국경제의 빠른 성장과 함께, 영어습득은 전망 있고 보다 나은 직업을 찾기 위한 필수적인 도구로 간주되고 있다. 그러나 영어교육과 학습의 결과는 훨씬 만족스럽지 못해 왔다. 영어를 학습하는 이들의 높은 시험점수와 낮은 의사소통 능력사이의 분명한 대조는 중국에서 영어교육이 성공적이지 못했다는 사실을 드러낸다. 학생중심과 교사중심의 교실, 실력위주 혹은 시험위주의 평가제도, 언어주입과 표현, 그리고 정확성과 유창함과 관련이 있는 중국 영어교육의 몇 가지 어려운 점들에 대해 한 대학영어교수의 관점에서 인지하고 논의할 것이다. 많은 문제점들 중에서, 그런 문제점들에 초점을 맞춤으로써, 영어교육과 학습에서 영어를 학습하는 이들의 언어의시소통능력을 이루기 위한 학생중심의 교실, 시험의 이로운 워시백(역류)효과, 언어 표현과 유창함을 향상시킴으로써 현역종사자들이 그런 복잡한 문제들을 해결하도록 몇 가지 가능성 있는 해결책들과 건설적인 의견들이 제시될 것이다.