Review of research on safety control of seismic wave and shock wave induced by underwater blasting

Yaxiong Peng,Li Wu,Ying Su,Binbin Zhu,Chunhui Chen,Bo Li 한국자원공학회 2017 Geosystem engineering Vol.20 No.3

The safety control methods and indexes of seismic wave and shock wave induced by underwater blasting are, respectively, elaborated in this paper. The single-factor and the double-factor safety control taking both vibration velocity and vibration frequency into consideration are comprehensively analyzed, and the weaknesses of the application scopes of both criteria in the safety performance evaluation of blasting vibration are discussed. Relative researches on the duration time of blasting are introduced, and the duration time for blasting is proposed to be embraced in the scope of safety control. Besides, the research progresses of safety control of water shock wave and aerial shock wave are, respectively, introduced, and the weaknesses of the above methods in the application to underwater blasting engineering are analyzed. Based on the analysis of the adverse effects of seismic wave and shock wave, the new idea to study the synergistic effects of both kinds of waves is put forward, and the comprehensive safety control method which includes both seismic wave and shock wave remains to be developed.

Effective transportation of electrons/Li ions in V2O3 nanoparticle/carboncoated stainless steel composite electrodes for lithium-ion storage

Yaxiong Tian,Jianghua Zhang,Tunmise Ayode Otitoju,Honggang Wang,Huaxia Chen,Lin Zhu,Zhongmin Feng,Ting Sun 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.114 No.-

The performance of V2O3 is threatened as a result of relatively sluggish electrons/ion transportation andstructural pulverization in lithium-ion batteries. The rational design of the electrode structure to exhibitgreat lithium storage of V2O3 is crucial. In this work, we report stable composite electrodes by integratingV2O3 nanoparticles with an uneven carbon-coated stainless-steel oxide (V2O3/C/SS) current collector viaan in-situ growth method. They allow fast electrical conductivity through the carbon coating and reductionstrategy. Meanwhile, the small nanoparticle size of V2O3 on V2O3/C/SS as well as the undestroyed 3DV–V skeleton are helpful to Li-ion diffusion. The weak interaction between Li ions and V2O3 achieves fastand high Li storage behavior, which proves by electrochemical kinetics analysis and DFT calculation. Theelectrode delivers high rate capacitive and long cycling stability with 564 mAh g1 and 310 mAh g1 at100 mA g1 and 1 A g1, respectively, and a specific capacity of 118 mAh g1 is achieved after 1000 cyclesat 5 A g1. The excellent electrochemical performance may be ascribed to the unique design for effectiveelectron and Li-ion transportation. This work offers a new prospect for the development of highperformancebinder-free V2O3-based electrodes.

Shaonian Songs from Northwestern China

Du Yaxiong 서울대학교 동양음악연구소 1998 동양음악 Vol.20 No.-

The Construction of Sanjo and Its Numbering System

Du, YaXiong 한국음악사학회 2002 한국음악사학보 Vol.29 No.-

산조는 '산'(散)과 '조'(調)라는 한자로 구성되었다. 산조의 장단도 '장'(長)과 '단'(短)의 한자로 구성되어 있다. 한국의 전통음악 중 정악(正樂)은 유교(儒敎)의 영향을 많이 받았음이 확실하다. 현재 한국에서는 유학적 전통이 전국적으로 차지하는 영향력은 대단하다. 예를 들건대, 한국의 국기인 태극기(太極旗)조차도 『역경』(易經)의 원리에 의하여 설계되었다. 이렇듯 한국 안에서의 유교영향은 무시할 수 없고, 전통음악에까지 그 영향을 미쳤다. 유교의 그런 영향이 민속음악에는 어떻게 반영됐는지가 궁금하였다. 그러므로 필자는 이 의문을 해결하기 위하여 산조의 수적(數的) 구조에 주목하였다. 산조 장단의 진양조가 6의 18박으로 되었고, 중모리가 네 개의 3박(3+3+3+3) 또는 세 개의 4박(4+4+4)으로 되어 있으며, 자진모리가 2박 계통의 수적 구조로 이루어졌다. 한국어로 mode는 조(調)이다. 이 조라는 용어는 선법(旋法)뿐만 아니라 선율(旋律), 그리고 선율형(旋律型) 등을 포괄하는 말로서 인도의 라가(raga)나 아라비아 또는 중앙아시아의 마캄(makam)의 뜻과 아주 흡사하다. 한국의 조는 평조(平調)와 계면조(界面調)가 있는데, 평조는 5음음계로 구성되었다. 그리고 계면조도 때로 5음음계로 사용되며, 때로 반음을 사용하여 온음음계로 구성되기도 한다. 계면조의 가장 중요한 특징이라면, 주음 4도 아래음에 강한 요성(搖聲)이 보이고, 주음 위의 음에서 흘러내리는 음이 보이는 점이다. 이재숙(李在淑)의 연구에 의하면, 일반적으로 산조의 악구(樂句)에 사용되는 음의 수가 셋 또는 넷임을 알 수 있으며, 또한 각 장단을 이루는 악구의 수가 3, 4, 6임을 볼 때, 그 숫자는 아주 중요한 의미를 지닌다. 여기서 왜 산조의 구성이 3, 4, 6과 같은 숫자와 관련됐는가에 대한 의문이 생긴다. 3, 4, 6의 숫자는 『역경』에서 아주 중요하다. 양효(陽爻)는 끊어지지 않는 효(爻)이고, 음효(陰爻)는 중간에 끊어진 효이다. 세 개의 효로 나열하면 여덟가지의 괘(卦)가 만들어진다. 이 괘는 자연·사회·개인 등의 여러 양상을 나타내게 된다. 8괘로부터 다시 64괘가 만들어진다. 『역경』에서 3은 8괘의 각 괘가 가지는 효(爻)의 수이며, 4는 아주 중요한 네 가지에 대한 상징이고, 6은 6효를 가지는 괘의 효수(爻數)이다. 13경 중의 하나인 『역경』은 중국의 유학경전(儒學經典)이라 할 수 있다. 위 와 같은 고찰을 통하여 산조에서 사용되는 숫자들이 무작위적으로 사용됐다고는 보여지지 않으며, 한국음악가들이 산조를 창작할 때 어떤 면에서는 유교적인 영향을 받았다고 볼 수 있다. 그러므로 한국의 민속음악을 보는 새로운 시각을 우리가 찾았다고 할 수 있다.

Research on Automatic Mapping Method of Geologic Column

Shao YanLin,Shao YaXiong,Xu XiaoHong,He ZhenMing,Li GongQuan 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.7

The realization of the digital reservoir can greatly improve the information level of the petroleum corporation in hydrocarbon exploration and development, reduce risk and improve efficiency. Wells are the core object of digital reservoir management. Geologic column of drilling is the main carrier of multi-source information. Automatic mapping method and multi-source information fusion of geologic column have become a research hotspot of digital reservoir construction. This paper describes current situation of the domestic reservoir management and practical problem of geological maps digitizing. The thought and process of geologic column automatic mapping, which are based on spatial information technology, are submitted. The partition of information bar is settled on. The three-tier system architecture of automatic mapping system is established. With the support of XML technology, XSD is used to make the parameter template of geologic column automatic mapping and realize corresponding configuration wizard. UML is used to design the automatic mapping system. The lithological plate and geological symbols is coded to realize automatic mapping of corresponding drawing elements. The drawing methods of logging and petrophysical data are improved and the visualization of curve and numerical stick figure is achieved. The integration method of casting photos, core images and geologic column is submitted. For the secondary development technology of ArcGIS Engine, object-oriented program is adopted to realize automatic mapping of geologic ArcGIS Engine column. This paper provides a new way for the geologic column mapping during the process of digital reservoir construction.

The influence of accelerometer epoch length on physical activity output in adolescent athletes

Jae-Hyun Lee,Soonhyun Kwon,Soyoon Lee,Se-Yeon Jang,Wooyeon Jo,Jaeho Jin,Yaxiong Zheng,Sang Ki Lee 한국운동재활학회 2023 JER Vol.19 No.6

Epoch in accelerometer measurements is an important option that af-fects the results of physical activity (PA) analysis. Many studies have been conducted to investigate the effect of epoch on PA output in ado-lescents, but few have been performed on highly active youth athletes. We aimed to examine the differences in energy expenditure and time spent in different activity intensities by applying various epoch lengths in adolescent athletes. The participants of this study comprised 31 male athletes aged 12 to 13 in basketball, soccer, and taekwondo teams. Ath-letes wore a tri-axial accelerometer attached to the right hip for 6 to 7 consecutive days, including sleeping time. Subsequently, the recorded data from the accelerometer were downloaded using the ActiLife soft-ware and analyzed by varying the epoch to 1, 10, 30, and 60 sec. Daily average metabolic equivalents (METs) increased as the epoch in-creased (F=2.918, P=0.037), showing a significant difference between 1 and 60-sec epochs. As epoch length increased, sedentary (0–1.5 METs) (F=94.001, P=0.000) and high intensity (6 METs and higher) activity time (F=3.536, P=0.017) decreased, while low (1.5–3 METs) (F=173.949, P= 0.000), moderate (3–6 METs) (F=70.792, P=0.000), and moderate-to-vig-orous activity (3 METs and higher intensity) (F=34.683, P=0.000) times increased. Comparing PA among adolescent athletes by varying epoch settings of accelerometers revealed differences in PA levels and time spent in different activity intensities. Future studies should consider the characteristic changes in the PA outputs according to the epoch length in very active adolescent athletes.