Auto-parametric resonance of framed structures under periodic excitations

Yuchun Li,Hongliang Gou,Long Zhang,Chenyu Chang 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.61 No.4

A framed structure may be composed of two sub-structures, which are linked by a hinged joint. One sub-structure is the primary system and the other is the secondary system. The primary system, which is subjected to the periodic external load, can give rise to an auto-parametric resonance of the second system. Considering the geometric-stiffness effect produced by the axially internal force, the element equation of motion is derived by the extended Hamilton\'s principle. The element equations are then assembled into the global non-homogeneous Mathieu-Hill equations. The Newmark\'s method is introduced to solve the time-history responses of the non-homogeneous Mathieu-Hill equations. The energy-growth exponent/coefficient (EGE/EGC) and a finite-time Lyapunov exponent (FLE) are proposed for determining the auto-parametric instability boundaries of the structural system. The auto-parametric instabilities are numerically analyzed for the two frames. The influence of relative stiffness between the primary and secondary systems on the auto-parametric instability boundaries is investigated. A phenomenon of the \"auto-parametric internal resonance\" (the auto-parametric resonance of the second system induced by a normal resonance of the primary system) is predicted through the two numerical examples. The risk of auto-parametric internal resonance is emphasized. An auto-parametric resonance experiment of a

The Breed and Sex Effect on the Carcass Size Performance and Meat Quality of Yak in Different Muscles

Zhang, Li,Sun, Baozhong,Yu, Qunli,Ji, Qiumei,Xie, Peng,Li, Haipeng,Wang, Li,Zhou, Yuchun,Li, Yongpeng,Huang, Caixia,Liu, Xuan Korean Society for Food Science of Animal Resource 2016 한국축산식품학회지 Vol.36 No.2

The carcass size performances and the meat quality of Gannan and Sibu yak were determined using M. supraspinatus (SU), M. longissimus thoracis (LT) and M.quadriceps femoris (QF). It is found that Sibu yak had significantly higher carcass weight (CW) than Gannan yak with difference of nearly 40 kg, as well as significantly higher eye muscle area (EMA), carcass thorax depth (CTD), round perimeter (RP), etc. The carcass performances of steer yak were significantly higher than heifer yak except meat thickness at round (MTR) (p<0.05). The results show that both yak breed and gender had significant effects on carcass performances. It could be seen that the variation of carcass size performances from breeds is as large as from gender (50.22% and 46.25% of total variation, respectively) through principal component analysis (PCA). Sibu yak had significantly higher L*, b*, WBSF, cooking loss and Fat content, while Gannan yak had significantly higher a*, press loss, protein content and moisture (p<0.05). Yak gender and muscle had insignificant effects on meat colour and water holding capacity (p>0.05). The variation of meat quality of yak from breed is up to 59.46% of total variation according to PCA. It is shown that the difference between breeds, for Gannan yak and Sibu yak, plays an important role in carcass size performance and meat quality.

The Breed and Sex Effect on the Carcass Size Performance and Meat Quality of Yak in Different Muscles

Li Zhang,Baozhong Sun,Qun-li Yu,Qiumei Ji,Peng Xie,Haipeng Li,Li Wang,Yuchun Zhou,Yongpeng Li,Caixia Huang,Xuan Liu 한국축산식품학회 2016 한국축산식품학회지 Vol.36 No.2

The carcass size performances and the meat quality of Gannan and Sibu yak were determined using M. supraspinatus (SU), M. longissimus thoracis (LT) and M.quadriceps femoris (QF). It is found that Sibu yak had significantly higher carcass weight (CW) than Gannan yak with difference of nearly 40 kg, as well as significantly higher eye muscle area (EMA), carcass thorax depth (CTD), round perimeter (RP), etc. The carcass performances of steer yak were significantly higher than heifer yak except meat thickness at round (MTR) (p<0.05). The results show that both yak breed and gender had significant effects on carcass performances. It could be seen that the variation of carcass size performances from breeds is as large as from gender (50.22% and 46.25% of total variation, respectively) through principal component analysis (PCA). Sibu yak had significantly higher L*, b*, WBSF, cooking loss and Fat content, while Gannan yak had significantly higher a*, press loss, protein content and moisture (p<0.05). Yak gender and muscle had insignificant effects on meat colour and water holding capacity (p>0.05). The variation of meat quality of yak from breed is up to 59.46% of total variation according to PCA. It is shown that the difference between breeds, for Gannan yak and Sibu yak, plays an important role in carcass size performance and meat quality.

Experimental study of upward flame spread of electrical wire with Cu-core under applied AC electric field

Zhisheng Li,Yuchun Zhang,Oh Boong Kwon,Jeong Park,Suk Ho Chang 한국연소학회 2022 KOSCOSYMPOSIUM논문집 Vol.2022 No.11

Effect of applied AC electric field on flame spread over an inclined electrical wire with Cu-core

Zhisheng Li,Yuchun Zhang,Oh Boong Kwon,Jeong Park,Suk Ho Chung 한국연소학회 2022 KOSCOSYMPOSIUM논문집 Vol.2022 No.5

R&D intensity, free cash flow, and technological innovation: evidence from high-tech manufacturing firms in China

Xin Kuang,Chen Xin,Zhang Ran,Sun Yuchun 기술경영경제학회 2019 ASIAN JOURNAL OF TECHNOLOGY INNOVATION Vol.27 No.2

Technological innovation, which can be classified into major and minor innovation, enables firms to gain competitive and sustainable advantage in the changing environment. R&D investment and financial resources are recognized as two critical factors for fostering technological innovation. Based on a panel dataset of 257 listed Chinese high-tech manufacturing firms over the period of 2008–2015, we explored the effect of R&D intensity on technological innovation and the moderating role of free cash flow using negative binormal regression models. Our results reveal that the relationship between R&D intensity and technological innovation (both major and minor innovation) follows an inverted U pattern in which technological innovation increases with R&D intensity at decreasing rates and falls gradually after R&D intensity exceeds a threshold. Our results also indicate that free cash flow plays a moderating role in the relationship between R&D intensity and major innovation but not in the relationship between R&D intensity and minor innovation. Our study draws attention to the improvement of R&D investment efficiency in high-tech manufacturing firms and sheds light on the importance of holding cash in major innovation-oriented firms.

Multi-constrained Shortest Disjoint Paths for Reliable QoS Routing

Ke Xiong,Zheng-ding Qiu,Yuchun Guo,Hongke Zhang 한국전자통신연구원 2009 ETRI Journal Vol.31 No.5

Finding link-disjoint or node-disjoint paths under multiple constraints is an effective way to improve network QoS ability, reliability, and so on. However, existing algorithms for such scheme cannot ensure a feasible solution for arbitrary networks. We propose design principles of an algorithm to fill this gap, which we arrive at by analyzing the properties of optimal solutions for the multi-constrained link-disjoint path pair problem. Based on this, we propose the link-disjoint optimal multi-constrained paths algorithm (LIDOMPA), to find the shortest link-disjoint path pair for any network. Three concepts, namely, the candidate optimal solution, the contractive constraint vector, and structure-aware non-dominance, are introduced to reduce its search space without loss of exactness. Extensive simulations show that LIDOMPA outperforms existing schemes and achieves acceptable complexity. Moreover, LIDOMPA is extended to the node-disjoint optimal multi-constrained paths algorithm (NODOMPA) for the multi-constrained node-disjoint path pair problem.

Detection of genome-wide structural variations in the Shanghai Holstein cattle population using next-generation sequencing

Dengying Liu,Zhenliang Chen,Zhe Zhang,Hao Sun,Peipei Ma,Kai Zhu,Guanglei Liu,Qishan Wang,Yuchun Pan 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.3

Objective: The Shanghai Holstein cattle breed is susceptible to severe mastitis and other diseases due to the hot weather and long-term humidity in Shanghai, which is the main distribution centre for providing Holstein semen to various farms throughout China. Our objective was to determine the genetic mechanisms influencing economically important traits, especially diseases that have huge impact on the yield and quality of milk as well as reproduction. Methods: In our study, we detected the structural variations of 1,092 Shanghai Holstein cows by using next-generation sequencing. We used the DELLY software to identify deletions and insertions, cn.MOPS to identify copy-number variants (CNVs). Furthermore, we annotated these structural variations using different bioinformatics tools, such as gene ontology, cattle quantitative trait locus (QTL) database and ingenuity pathway analysis (IPA). Results: The average number of high-quality reads was 3,046,279. After filtering, a total of 16,831 deletions, 12,735 insertions and 490 CNVs were identified. The annotation results showed that these mapped genes were significantly enriched for specific biological functions, such as disease and reproduction. In addition, the enrichment results based on the cattle QTL database showed that the number of variants related to milk and reproduction was higher than the number of variants related to other traits. IPA core analysis found that the structural variations were related to reproduction, lipid metabolism, and inflammation. According to the functional analysis, structural variations were important factors affecting the variation of different traits in Shanghai Holstein cattle. Our results provide meaningful information about structural variations, which may be useful in future assessments of the associations between variations and important phenotypes in Shanghai Holstein cattle. Conclusion: Structural variations identified in this study were extremely different from those of previous studies. Many structural variations were found to be associated with mastitis and reproductive system diseases; these results are in accordance with the characteristics of the environment that Shanghai Holstein cattle experience.