FINITE GROUPS WITH SOME SEMI-p-COVER-AVOIDING OR ss-QUASINORMAL SUBGROUPS

Qingjun Kong,Xiuyun Guo 대한수학회 2014 대한수학회보 Vol.51 No.4

Suppose that G is a finite group and H is a subgroup of G. H is said to be an ss-quasinormal subgroup of G if there is a subgroup B of G such that G = HB and H permutes with every Sylow subgroup of B; H is said to be semi-p-cover-avoiding in G if there is a chief series 1 = G0 < G1 < · · · < Gt = G of G such that, for every i = 1, 2, . . . , t, if Gi/Gi−1 is a p-chief factor, then H either covers or avoids Gi/Gi−1. We give the structure of a finite group G in which some subgroups of G with prime-power order are either semi-p-cover-avoiding or ss-quasinormal in G. Some known results are generalized.

Experimental Investigation on Fatigue Strength of Joints between SRC Beams and Concrete-Filled RHS Columns

Qingjun Xian,Le-Wei Tong,Liying Zhou,Yiyi Chen 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.5

Fatigue behavior, failure mechanism and fatigue strength of joints between steel reinforced concrete (SRC) beams and Concrete Filled Rectangular Hollow Section (CFRHS) columns is discussed in this paper. Three identical beam-to-column joint specimens were designed and tested under static loading and two stages of fatigue loading. In the first stage of fatigue loading, the specimens were subjected to design fatigue load for 2 million cycles, while during the second stage, they were loaded to failure under increased fatigue load in order to know failure mechanism and fatigue strength. It is found that the joints satisfied design requirements when subjected to static loading and design fatigue loading. Fatigue failure occurred after these joints were applied higher-level fatigue loading. The crack initiated at the weld toe of stud or stirrup hole in the upper flange of I-shaped steel in certain SRC beam, and then it propagated along flange width in winding trajectory until fatigue fracture occurred. Stress amplitude of tension flange in SRC beam can be regarded as the parameter representing fatigue strength of the joints. S-N curves in related codes are selected to evaluate fatigue strength of the joints. The design method is suggested to consider fatigue design of the joints.

An inerter-system chain and energy-based optimal control of adjacent single-degree-of-freedom structures

Qingjun Chen,Zhipeng Zhao,Ruifu Zhang 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.28 No.2

Because of the limited land resources and preference of centralized services, more structures are often built close to each other, correspondingly yielding a demand that mitigates the dynamic responses of adjacent structures. Utilizing the intrinsic potential of the inerter to improve structural energy performances, an inerter-system chain is proposed for the adjacent singledegree- of-freedom structures, which forms a novel configuration featuring the reduction in input energy transmitted to the adjacent structures. The inerter-system chain is realized by two end-placed inerter-dashpot dampers and inter-placed springinerter- dashpot elements arranged in parallel. Stochastic energy balance analysis is conducted to derive a closed-form energy equation that reveals the energy basis of the inerter-system chain. An energy-based and bi-objective optimization strategy is developed with simultaneous consideration of displacement and energy performances, particularly easy-to-use design formulae being derived. The findings of this study show that a complete inerter-system chain exhibits a significant multi-reduction in the structural displacement, shear force, and dissipation energy burden. Particularly, the effectiveness of reducing the input power and vibrational energy transmitted into the entire structures counts on the series inerter-chain, which differentiates the proposed chain from alternative layouts. The proposed energy-based design framework is capable of minimizing the energy dissipation cost, with target displacement control demand satisfied.

A new multi-class classification method based on minimum enclosing balls

QingJun Song,XingMing Xiao,HaiYan Jiang,XieGuang Zhao 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.8

With respect to classification problems, the Minimum enclosing ball (MEB) method was recently studied by some scholars as a newsupport vector machine. As a nascent technology, however, MEB reports poor adaptability for different types of samples, especiallymulti-class samples. In this paper, we propose a new multi-class classification method based on MEB. This method is derived from eachclass sample center and radius with the Gaussian kernel width factor parameter σ, which is labelled as σ-MEB. σ is a variable parameteraccording to the different sample characteristics. When this parameter is considered, the multi-class classifier is easy to adapt and is robustin diverse datasets. The quadratic programming problem was transformed into its dual form with Lagrange multipliers using thismethod. Finally, we applied sequential minimal optimization method and Karush—Kuhn—Tucker conditions to accelerate the trainingprocess. Numerical experiment results indicate that given different types of samples, the proposed method is more accurate than themethods with which it is compared. Moreover, the proposed method reports values in the upper quantile with respect to adaptation performance.

Preparation and Properties of HUHPC with Low Shrinkage and High Impact Resistance

Qingjun Ding,Jinhua Gong,Gaozhan Zhang,Yang Liu,Jun Yang,Yongyuan Zhang,Peng Zhou 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.8

At present, nuclear energy is widely used to reduce pollution and clean energy. However, the radiation-proof concrete currently used to prepare nuclear shields cannot meet the protection requirements of nuclear safety. Therefore, there is an urgent need to develop radiation-proof concrete materials with high impact resistance and ultra-high strength. In this paper, the low-shrinkage, high-impact Heavy Ultra-High-Performance Concrete (HUHPC) was designed by the following innovative methods: Porous high titanium heavy slag sand (HTHS) (industrial solid waste) with “slow-water release” effect and expansion agent were synergistically used to improve volume stability; Irregular HTHS with “embedded lock” effect and steel fibers were synergistically utilized to enhance impact resistance; Heavy ilmenite sand was used to lift volume weight. The workability, mechanical properties, volume stability, impact resistance, and microstructure were studied. The results show that the designed HUHPC volume weight is more than 2,800 kg/m3 which can enhance the radiation protection performance greatly. The 180 d shrinkage of HUHPC is less than 400 με, which volume stability is improved by more than 30%. The addition of lithium carbonate slightly decreased the 28 d strength of HUHPC, but the appropriate admixture amount (0.9%) could improve the impact resistance of HUHPC by 33%.

Evaluation and optimization of SrCo0.9Ta0.1O3−δ perovskite as cathode for solid oxide fuel cells

Qingjun Zhou,Tong Wei,Yihua Shi,Songqing Guo,Yan Li,Jingxin Su,Huan Ren,Yin Zhu,김경국 한국물리학회 2012 Current Applied Physics Vol.12 No.4

The SrCo0.9Ta0.1O3-δ (SCT) perovskite-type oxide is synthesized by the conventional solid state reaction method and examined as an alternative cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). The electrical conductivity of SCT sample reaches 250e152 S cm-1 in the temperature range 600e800 ℃. SCT exhibits good chemical compatibility with the intermediate-temperature electrolyte material Sm0.2Ce0.8O1.9 (SDC). The average thermal expansion coefficient of SCT is 21.4 × 10-6 K-1. The cathode area specific resistance (ASR) of SCT is only 0.095 U cm2 at 750 ℃ and it decreases to 0.068 U cm2 when SDC is added to form a SCT-SDC composite cathode. The results indicate that the SCT can be a promising alternative cathode material for IT-SOFCs.

Seismic Performance of a Subway Station-Tunnel Junction Structure: A Shaking Table Investigation and Numerical Analysis

Qingjun Chen,Tianyu Zhang,Na Hong,Bin Huang 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.5

Damage cases show that during earthquakes, the sharp stiffness mutation of subway station-tunnel junction structures can lead to dislocations at the connections. To address this, shaking table tests were conducted followed by numerical simulations of a typical junction structure with rigid connections. The modeling method was verified based on the test results. Furthermore, numerical models of junction structures with rigid and flexible connections, single stations, and single tunnels were built, and deformation modes and stress distributions were comparatively analyzed. Combining the experimental and numerical results, it is found that there exists an intensive deformation inconsistency between the stations and the tunnels responsible for the junction structures’ dislocation failures. The station operates in both racking and distortion deformation modes when the tunnel undergoes ovaling deformation. The tunnel bends relative to the end wall at the connection. The junction structure with rigid connections is most at risk at the point located at the tunnel section connected to the end wall and near the bottom plate-sidewall joint. With flexible connections, the tunnels integrally translate relative to the end wall, and the stress response of the end wall openings can be larger than those with rigid connections.

The Automatic Recognition of Large Ball Valve Sealing Bolt Based on Digital Image

Qingjun Song,Xingming Xiao,Haiyan Jiang 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.6

In this paper, we put forward an effective algorithm for edge detection based on combination of multi-shape/scale Mathematical morphology and wavelet transformation. Firstly, the bimodal method and multi-threshold method were combined for the image segmentation. Then, the image edge was detected by the algorithm. Finally, the angle between the bolt and manipulator was calculated using the rotation conversion matrix. With the systematic error and correlation coefficient, the calculated angle was verified. Experimental results show that the method can protect the edge integrity of the nut image, with fast processing speed and strong anti-noise ability. The work in this paper provides a theoretical basis for the automatic recognition in the large ball valve sealing bolt system.

Exploring the Fusion of Children's Cognitive Features in Pop-Up Book Design with Traditional Chinese Medicine Culture: Enhancing Cognitive Abilities, Focus, and Interest

徐庆军(Qingjun XU) Korea Institute for Humanities and Social Sciences 2023 Journal of Global Arts Studies (JGAS) Vol.1 No.1

[Background] Pop-Up Books play a crucial role in early childhood education, particularly in enhancing overall development through unique interactivity and visual impact. [Purpose] To effectively inherit and innovate Traditional Chinese Medicine (TCM) culture, aiding in its integration into national education. [Method]Combining the distinctive presentation of pop-up books with virtual reality technology and the fundamental concepts of TCM, creating engaging and age-appropriate TCM educational materials for young children. [Result] Developing pop-up books tailored to children's cognitive abilities, incorporating TCM education into early childhood curriculums, and sparking interest in TCM culture. [Conclusion] The integration of pop-up book design, virtual reality, and cultural elements supports national efforts to disseminate and preserve cultural heritage, effectively transmitting excellent national culture in early education. 【背景】幼儿立体书(Pop-Up Book)在启蒙教育中起重要作用,特别是如何通过其独特的互动性和视觉效果来促进幼儿的全面发展。【目的】 实现中医药文化更加有效地传承与创新发展。助力中医药文化传播行动把中医药文化贯穿国民教育始终;【方法】 以设计幼儿中医启蒙立体书为出发点, 将立体书独特的展现形式与虚拟现实技术和中医传统文化基础内容相结合,利用开发立体书的趣味性和活动性设计适合幼儿的中医药基础知识的图书;【结果】 设计出适合幼儿认知特征的中医启蒙教育和幼儿教学的立体书. 把中医药文化教育融入幼儿启蒙教育课程, 让幼儿在学习了解中华中医药文化魅力的同时, 激发幼儿对中医文化的探索与学习欲望。【结论 】立体书籍设计+ 虚拟现实技术与民族文化相结合可以更好的助力国家推动民族文化传播、传承的政策,有利于在幼儿启蒙阶段教育中的更好的传承优秀的民族文化。

FINITE GROUPS WITH SOME SEMI-p-COVER-AVOIDING OR ss-QUASINORMAL SUBGROUPS

Kong, Qingjun,Guo, Xiuyun Korean Mathematical Society 2014 대한수학회보 Vol.51 No.4

Suppose that G is a finite group and H is a subgroup of G. H is said to be an ss-quasinormal subgroup of G if there is a subgroup B of G such that G = HB and H permutes with every Sylow subgroup of B; H is said to be semi-p-cover-avoiding in G if there is a chief series 1 = $G_0$ < $G_1$ < ${\cdots}$ < $G_t=G$ of G such that, for every i = 1, 2, ${\ldots}$, t, if $G_i/G_{i-1}$ is a p-chief factor, then H either covers or avoids $G_i/G_{i-1}$. We give the structure of a finite group G in which some subgroups of G with prime-power order are either semi-p-cover-avoiding or ss-quasinormal in G. Some known results are generalized.