Finite element analysis and axial bearing capacity of steel reinforced recycled concrete filled square steel tube columns

Jing Dong,Hui Ma,Changming Zou,Yunhe Liu,Chen Huang 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.1

This paper presents a finite element model which can simulate the axial compression behavior of steel reinforced recycled concrete (SRRC) filled square steel tube columns using the ABAQUS software. The analytical model was established by selecting the reasonable nonlinear analysis theory and the constitutive relationship of material in the columns. The nonlinear analysis of failure modes, deformation characteristics, stress nephogram, and load-strain curves of columns under axial loads was performed in detail. Meanwhile, the influences of recycled coarse aggregate (RCA) replacement percentage, profile steel ratio, width thickness ratio of square steel tube, RAC strength and slenderness ratio on the axial compression behavior of columns were also analyzed carefully. It shows that the results of finite element analysis are in good agreement with the experimental results, which verifies the validity of the analytical model. The axial bearing capacity of columns decreased with the increase of RCA replacement percentage. While the increase of wall thickness of square steel tube, profile steel ratio and RAC strength were all beneficial to improve the bearing capacity of columns. Additionally, the parameter analysis of finite element analysis on the columns was also carried out by using the above numerical model. In general, the SRRC filled square steel tube columns have high bearing capacity and good deformation ability. On the basis of the above analysis, a modified formula based on the American ANSI/AISC 360-10 was proposed to calculate the nominal axial bearing capacity of the columns under axial loads. The research conclusions can provide some references for the engineering application of this kind of columns.

Culture of a Whole Porcine Liver Ex Situ without Red Blood Cells

( Jing Dong ),( Lingling Xia ),( Hefang Shen ),( Congwen Bian ),( Sujin Bao ),( Ming Zhang ),( Yan Dai ),( Yanhong Xu ),( Qiru Xiong ),( Jianjian Xu ),( Lili Xu ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Liver transplantation is an effective approach to end-stage liver disease. Shortage of donor liver and increased waiting time for liver transplantation necessitate the development of an organ culture system by which livers can be cultured and maintained ex situ for a prolonged period of time. The aim of this work is to test whether cell culture condition in vitro could be used to culture whole livers ex situ without the use of erythrocytes. Methods: Eight castrated male land race/farm young porcine livers were exposed to 30 min warm ischemia and 30 min cold perfusion. Livers were isolated and connected to an ex situ liver culture system using a standard culture medium RPMI 1640 supplied with 10% of fetal calf serum and sufficient dissolved oxygen under a normothermic condition for 6 hours. Metabolic biomarkers, bile and urea production, hepatic cell viability, and histology analysis of biopsies were performed and analyzed. Results: Dissociated porcine hepatic cells survived and grew in vitro under the standard RPMI 1640 culture medium. When the same RPMI 1640 medium supplemented with 10% of FCS and sufficient oxygen was used to culture livers ex situ, over 98% of liver cells were viable for at least 6 hours during ex situ whole organ culture based on the results from biochemical assays. Conclusions: Our data demonstrate that the liver culture system established in this work can be used to culture whole livers ex situ in the absence of erythrocytes.

Research on the Re-use of Spaces for Abandoned Factory Culture Based on the Experience Level-Taking Beijing Shougang industrial Park as an Example

Jingdong He(하정동),Chul Soo Kim(김철수) 한국디자인학회 2023 한국디자인학회 학술발표대회 논문집 Vol.2023 No.10

Interactive Experience Design in History Museums Based on Distributed Cognition :Focusing on the Case of History Museums in China

Jingdong He,김철수 사단법인 한국융합기술연구학회 2024 아시아태평양융합연구교류논문지 Vol.10 No.2

In the rapid development of experience economy, the cultural experience environment of history museums is gradually enriched, and the interactive experience of museum visitors becomes more and more important. Distributed cognition theory is one of the cognitive theories that emphasize the interaction between the cognitive subject and the environment as a complete system, which precisely solves the problem of a single cognitive approach in traditional history museums due to the limited function and participation. This study aimed to redefine the interactive experiential elements of museums in conjunction with distributed cognition theory in order to enhance visitor interaction and experience. The scope of the study was limited to the experiential elements of history museums and the interactive experience processes based on distributed cognition (content interaction, instrumental interaction and contextual interaction), and the main methodology used was a case study. The types of guiding devices, the five senses of experience, and the ways of interactive experience based on them were analyzed in three museums: the Forbidden City Museum in Beijing, the Terracotta Warriors and Horses Museum in Qin Shi Huang, and the Dunhuang Museum. Various design approaches that help enhance visitors' sensory experience and engagement are demonstrated. Results of the study showed that the elements of interactive experience design for history museums under the distributed cognition theory and explains how these elements affect the feelings and experiences of museum visitors. Each of the three museums in the case study underperformed in their respective cognitive, interactive and experiential elements. Based on these findings, it is necessary to add and enrich the interactive experience elements for the five senses of museum visitors' experience. To make the cognitive process of museum visitors more fluid. The study concludes that interactive experience design based on distributed cognition theory improves visitor engagement but also opens up new possibilities for interactive and educational experiences in history museums. This study highlights the need for museums to adapt to modern technological trends and cognitive theories in order to remain relevant and engaged in the digital age. Ultimately, this thesis contributes to the wider field of design by demonstrating the practical applications and benefits of distributed cognitive theory in creating more dynamic, interactive, and personalised museum experiences.

Between a Rock and a Very Hard Place: China’s Ukraine War Dilemma

Jingdong Yuan,Fei Su 동아시아재단 2022 Global Asia Vol.17 No.2

Cross-Strait Relations 2008-2016: Progress, Problems, and Prospects

( Jingdong Yuan ) 서울대학교 통일평화연구원 2016 Asian Journal of Peacebuilding Vol.4 No.2

Cross-Strait relations over the past eight years have witnessed noticeable improvement and contributed to peace and stability in the region. This article argues that Beijing and Taipei have yet to tackle more fundamental issues and move forward with political negotiations on the status of cross-Strait relations. The growing military imbalance over the past decade has eroded Taiwan`s security and undermined its ability to negotiate with Beijing from a position of strength. With the DPP`s Tsai winning the 2016 election and her refusal to formally embrace the “1992 Consensus,” tensions could flare up again. Washington remains committed to Taiwan`s security through defense cooperation and arms sales, but its willingness to do so will be tested by a rising China determined to resolve the issue on its own terms.

Exploring cognitive trajectories and their association with physical performance: evidence from the China Health and Retirement Longitudinal Study

Jingdong Suo,Xianlei Shen,Jinyu He,Haoran Sun,Yu Shi,Rongxin He,Xiao Zhang,Xijie Wang,Yuandi Xi,Wannian Liang 한국역학회 2023 Epidemiology and Health Vol.45 No.-

OBJECTIVES: The long-term trends of cognitive function and its associations with physical performance remain unclear, particularly in Asian populations. The study objectives were to determine cognitive trajectories in middle-aged and elderly Chinese individuals, as well as to examine differences in physical performance across cognitive trajectory groups. METHODS: Data were extracted from the China Health and Retirement Longitudinal Study. A total of 5,701 participants (47.7% male) with a mean age of 57.8 (standard deviation, 8.4) years at enrollment were included. A group-based trajectory model was used to identify cognitive trajectory groups for each sex. Grip strength, repeated chair stand, and standing balance tests were used to evaluate physical performance. An ordered logistic regression model was employed to analyze differences in physical performance across cognitive trajectory groups. RESULTS: Three cognitive trajectory groups were identified for each sex: low, middle, and high. For both sexes, higher cognitive trajectory groups exhibited smaller declines with age. In the fully adjusted model, relative to the low trajectory group, the odds ratios (ORs) of better physical performance in the middle cognitive group were 1.37 (95% confidence interval [CI], 1.17 to 1.59; p<0.001) during follow-up and 1.40 (95% CI, 1.20 to 1.64; p<0.001) at the endpoint. The ORs in the high trajectory group were 1.94 (95% CI, 1.61 to 2.32; p<0.001) during follow-up and 2.04 (95% CI, 1.69 to 2.45; p<0.001) at the endpoint. CONCLUSIONS: Cognitive function was better preserved in male participants and individuals with higher baseline cognitive function. A higher cognitive trajectory was associated with better physical performance over time.

Nutrigenomics Approach-A Strategy for Identification of Nutrition Responsive Genes Influencing Meat Edible Quality Traits in Swine

Yin, Jingdong,Li, Defa Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.4

In the last 20 years, meat quality, especially meat edible quality has become a more intriguing topic in the field of swine production. In this paper, we briefly review the progress of meat quality research from the aspects of genetic selection and nutritional modulation, and propose a possible approach -nutrigenomics- to explore the nutrition-responsive major genes that affect meat quality formation during the growing and fattening of pigs.

Quantitative Determination of the Chromophore Alignment Induced by Electrode Contact Poling in Self-Assembled NLO Materials

김태동,Jingdong Luo,Alex K.-Y. Jen 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.4

The electrode contact poling is one of the efficient tools to induce a stable polar order of nonlinear optical (NLO) chromophores in the solid film. Self-assembled NLO chromophores with high electro-optic (E-O) activities were utilized for quantitative determination of the chromophore order induced under contact poling by spectroscopic changes. We found that NLO chromophores rarely decompose under the high electric field during contact poling. The absorption spectra were de-convoluted into a sum of Gaussian components to separate energy transitions for a binary composite system which contains a secondary guest chromophore AJC146 in the self-assembled chromophore HDFD. Poling efficiency was significantly improved in the binary system compared to the individual components.

Unified Model for Performance Analysis of IEEE 802.11 Ad Hoc Networks in Unsaturated Conditions

( Changchun Xu ),( Jingdong Gao ),( Yanyi Xu ),( Jianhua He ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.2

IEEE 802.11 standard has achieved huge success in the past decade and is still under development to provide higher physical data rate and better quality of service (QoS). An important problem for the development and optimization of IEEE 802.11 networks is the modeling of the MAC layer channel access protocol. Although there are already many theoretic analysis for the 802.11 MAC protocol in the literature, most of the models focus on the saturated traffic and assume infinite buffer at the MAC layer. In this paper we develop a unified analytical model for IEEE 802.11 MAC protocol in ad hoc networks. The impacts of channel access parameters, traffic rate and buffer size at the MAC layer are modeled with the assistance of a generalized Markov chain and an M/G/1/K queue model. The performance of throughput, packet delivery delay and dropping probability can be achieved. Extensive simulations show the analytical model is highly accurate. From the analytical model it is shown that for practical buffer configuration (e.g. buffer size larger than one), we can maximize the total throughput and reduce the packet blocking probability (due to limited buffer size) and the average queuing delay to zero by effectively controlling the offered load. The average MAC layer service delay as well as its standard deviation, is also much lower than that in saturated conditions and has an upper bound. It is also observed that the optimal load is very close to the maximum achievable throughput regardless of the number of stations or buffer size. Moreover, the model is scalable for performance analysis of 802.11e in unsaturated conditions and 802.11 ad hoc networks with heterogenous traffic flows.