Hot Stamping Die Design for Vehicle Door Beams using Ultra-High Strength Steel

Chao Jiang,Zhongde Shan,Bailiang Zhuang,Milan Zhang,Ying Xu 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

The energy saving and safety is the eternal theme of development of automobile industry. Ultra-high strength steel automotive body structures of hot stamping have been widely used with these dual advantages that reducing vehicle weight while enhancing safety performance at the same time. The forming and quenching integration die was investigated in this paper with a vehicle door beam as an example, especially the whole die structure and hot stamping process were optimized through numerical simulation of die strength, cooling pipe arrangement and other related factors, and beam samples with tensile strength 1550Mpa, elongation rate 6.5% and shape accuracy of ±0.3mm were produced by this die. Moreover, the stiffness increased by 2.2 times than the original tube beam and 3.8 times of the intensity, which led to full score in C-NCAP Crash Test. By reducing the thickness cross section and the depth of drawing comparing with the original tubular beam,door beam weight could be reduced by 9.32%, which had effective energy-saving and emission-reduction effect.

Video Multiple Classification Algorithm Based on SVM

Chao Jiang,Shuguang Wang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.7

The performance of video automatic classification algorithm depends largely on the extraction of video features and selection of classification algorithm. From the perspective of video contents and video style type, the paper presents a new feature representation scheme, i.e. MPEG-7 visual description sub-combination model, a new method based on support vector machine (SVM) to solve problems with existing algorithms, by analyzing visual differences between five types of videos. Also we improve the classifier decision scheme and then propose the secondary prediction mechanism based on SVM 1-1 approach, improving the accuracy of SVM multi-classification method. The experimental results indicate that the proposed method manifests differences of different videos about feature selection, enhances the discrimination ability of videos pending for classification and increases the effectiveness of SVM multi-video classification.

Expression of Human FGF18 by Fusion with Oleosin in Arabidopsis thaliana Seeds

Chao Jiang,Xiaokun Li,Feng Zhai,Nuo Xu,Jing Yang,Yunpeng Wang,Libo Jin,Haiyan Li 한국식물학회 2018 Journal of Plant Biology Vol.61 No.3

Expression of recombinant human fibroblast growthfactor 18 (hFGF18) in mammalian cells and Escherichia colihas been extensively used for fundamental research andclinical applications, but they are difficult, expensive. Theexpression of recombinant proteins fused to oleosin proteinhave distinct advantages, such as safety, ease, low cost. Sowe have expressed hFGF18 fused to oleosin protein in the oilbodies of Arabidopsis thaliana (A. thaliana) and screen theproliferation effect of NIH3T3 cells. The vector of oleosinhFGF18fusion gene was constructed and transformed intowild A. thaliana. Transformed A. thaliana lines were obtainedby the floral dip method and confirmed using polymerasechain reaction (PCR). The PCR results indicated that theoleosin-hFGF18 fusion gene was integrated into the A. thaliana genome. The oil bodies expression of oleosin-hFGF18was confirmed by sodium dodecyl sulfate polyacrylamidegel electrophoresis and western blotting. The biologicalactivity showed that oil bodies expressing oleosin-hFGF18could stimulate the proliferation of NIH3T3 cells.

Local Strain-Based Low-Cycle Fatigue Assessment of Joint Structure in Steel Truss Bridges During Earthquakes

Chao Jiang,Takeshi Hanji,Kazuo Tateishi,Masaru Shimizu 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.5

During the 2011 Tohoku Earthquake, a truss bridge joint structure was cracked due to large cyclic deformation, making us recognize the importance of assessing the seismic performance of joint structures in truss bridges from the viewpoint of low-cycle fatigue. In this study, seismic response analysis of an actual deck truss bridge was performed under diff erent seismic waves, and local strain behavior generated at welded joints around a joint structure was clarifi ed using a zooming analysis technique. The results revealed the possibility that welded joints for a lateral gusset-plate in a joint structure can be cracking sites during earthquakes. In addition, it was indicated that seismic isolation bearings can signifi cantly reduce the local strain at the joint structure and improve its low-cycle fatigue performance. Moreover, as a simple countermeasure, weld toe treatment by grinding is also eff ective to decrease the possibility of low-cycle fatigue cracking at the joint structure.

Fatigue Crack Growth Characteristics of Several Kinds of Structural Steels Under Low-Cycle Fatigue Loading

Chao Jiang,Takeshi Hanji,Kazuo Tateishi,Masaru Shimizu 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.1

Because low-cycle fatigue is one of the failure modes in steel structures during earthquakes, crack growth prediction in the low-cycle fatigue region has become an important factor in the evaluation of the seismic performance of steel structures. This study conducted fatigue crack growth tests with several kinds of structural steels to clarify their crack growth behaviour in the low-cycle fatigue region. These tests employed an elastic compliance technique usually used in the high-cycle fatigue region to determine crack size. Before applying the elastic compliance method to a low-cycle fatigue crack growth test, a correlation between specimen load-line crack-opening elastic compliance and crack size was analytically derived. The test results indicated that crack sizes obtained by the elastic compliance method agree relatively well with those actually measured from images. Moreover, it was revealed that the crack growth rate can be correlated with the cyclic J-integral range calculated by finite element analysis, and that the relationships between the crack growth rate and the cyclic J-integral range are similar regardless of the steel type.

Autonomous Lane Keeping System: Lane Detection, Tracking and Control on Embedded System

Chao Jiang,Mingjie Liu,Xutao Deng,Zhen Lei,Changhao Piao 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.1

Autonomous lane keeping system is the key technique to autonomous driving. It includes lane detection, lane tracking and control. It has been developed enormously, but it is still a challenge work due to diff erent factors such as illumination, general hyper-parameters setting for diff erent road condition and lane boundary correction. In addition, due to imbalance on accuracy and processing time, it is hard to conduct in embedding system. In this study, an autonomous lane keeping system is developed based on deep learning. First, a lane detection and tracking system is designed, which is robust to lane boundary correction. Especially for lane detection, a light-weight network named as LaneFCNet is proposed, which can balance accuracy and processing time. Then, lane tracking was followed by detector to improve the detection performance and create autonomous driving trajectory. Finally, to brief lane fi tting problem, it was treated as ridge regression problem, which can enhance the eff ectiveness to the whole system. Experimental results show that our integrated lane detection and tracking system can trade off accuracy and processing time and the whole line keeping system is robust enough to autonomous driving.

The funding factor: a cross-disciplinary examination of the association between research funding and citation impact

Yan, Erjia,Wu, Chaojiang,Song, Min Springer-Verlag 2018 Scientometrics Vol.115 No.1

<P>This paper intends to illuminate the relationship between science funding and citation impact in seven STEMM disciplines (science, technology, engineering, mathematics, and medicine). Using a regression model with Heckman bias correction, we find that funding has a positive, significant association with a paper's citations in STEMM fields. Further analyses show that this association is magnified by the factors of multiple authorship and multiple institutions. For funded papers in STEM, multi-author and multi-institution papers tend to receive even more citations than single-authored and single-institution papers; however, funded papers in Medicine received less gain in citation impact when either factor is considered. Based on the finding that funding support has a stronger association with citation impact when it is treated as a binary variable than as a count variable, this paper recommends the allocation of funding to researchers without active funding support, instead of giving awards to those with multiple funding supports at hand.</P>

Impact resistance and damage assessment of steel beams with different web openings

Huayan Chen,Jianzhong Huang,Chaojiang Fu,Sixiang Wang,Fengxuan Wang,Caisong Luo,Bizhen Wang 한국강구조학회 2024 International Journal of Steel Structures Vol.24 No.2

To investigate the impact resistance of steel beams with diff erent web openings, falling-hammer impact trials and numerical models analyses were performed, focusing on the impact energy, inter-opening space, and opening diameter. The impact resistance of steel beams with diff erent web openings was analyzed, and damage-assessment curves for web-opening steel beams (WOSBs) under impact loads were established. The results showed that web-hexagonal-opening steel beams (WHOSBs) yielded greater damage-related deformation than web-circular-opening steel beams (WCOSBs) for the same impact energy. The average maximum mid-span displacement of the WCOSBs under the falling-hammer was 86.49% that of the WHOSBs, whereas the average energy absorption rate was 6.07% higher. The WCOSBs were more resistant to impacts than the WHOSBs. The impact velocity and mass were the key damage-assessment parameters, and velocity–mass damage-assessment curves and determination equations were established according to on the WOSBs’ maximum mid-span displacement under hinge-supported restraints at both ends. Thus, this study will serve as a reference for assessing the damages of WOSBs subjected to impacts.

Alternative Splicing of Breast Cancer Associated Gene BRCA1 from Breast Cancer Cell Line

Lixia, Miao,Zhijian, Cao,Chao, Shen,Chaojiang, Gu,Congyi, Zheng Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.1

Breast cancer is the most common malignancy among women, and mutations in the BRCA1 gene produce increased susceptibility to these malignancies in certain families. In this study, the forward 1-13 exons of breast cancer associated gene BRCA1 were cloned from breast cancer cell line ZR-75-30 by RT-PCR method. Sequence analysis showed that nine BRCA1 splice forms were isolated and characterized, compared with wild-type BRCA1 gene, five splice forms of which were novel. These splice isoforms were produced from the molecular mechanism of 5' and 3' alternative splicing. All these splice forms deleting exon 11b and the locations of alternative splicing were focused on two parts:one was exons 2 and 3, and the other was exons 9 and 10. These splice forms accorded with GT-AG rule. Most these BRCA1 splice variants still kept the original reading frame. Western blot analysis indicated that some BRCA1 splice variants were expressed in ZR-75-30 cell line at the protein level. In addition, we confirmed the presence of these new transcripts of BRCA1 gene in MDA-MB-435S, K562, Hela, HLA, HIC, H9, Jurkat and human fetus samples by RT-PCR analysis. These results suggested that breast cancer associated gene BRCA1 may have unexpectedly a large number of splice variants. We hypothesized that alternative splicing of BRCA1 possibly plays a major role in the tumorigenesis of breast and/or ovarian cancer. Thus, the identification of cancer-specific splice forms will provide a novel source for the discovery of diagnostic or prognostic biomarkers and tumor antigens suitable as targets for therapeutic intervention.

Strain Improvement and Metabolic Flux Modeling of Wild-type and Mutant Alcaligenes sp. NX-3 for Synthesis of Exopolysaccharide Welan Gum

Hui Li,Hong Xu,Sha Li,Hao Xu,Chaojiang Guo,Pingkai Ouyang,Hanjie Ying 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.5

Low-energy nitrogen ion beam implantation technique was used for the strain improvement of Alcaligenes sp. NX-3 for the production of exopolysaccharide welan gum. A high welan gum producing mutant, Alcaligenes sp. NX-3-1, was obtained through 20 keV N+ ion beam irradiation. Starting at a concentration of 50 g/L of glucose, mutant NX-3-1 produced 25.0 g/L of welan gum after 66 h of cultivation in a 7.5 L bioreactor, which was 34.4% higher than that produced by the wild-type strain. The results of metabolic flux analysis showed that the glucose-6-phosphate and acetyl coenzyme A nodes were the principle and flexible nodes, respectively. At the glucose-6-phosphate node, the fraction of carbon measured from glucose-6-phosphate to glucose-1-phosphate was enhanced after mutagenesis, which indicated that more flux was used to synthesize welan gum in the mutant. By analyzing the activities of related enzymes in the biosynthetic pathway of sugar nucleotides essential for welan gum production, we found that the specific activities of phosphoglucomutase, UDP-glucose pyrophosphorylase,UDP-glucose dehydrogenase, and dTDP-glucose pyrophosphorylase in the mutant strain were higher than those in the wild-type strain. These improvements in enzyme activities could be due to the affected of ion beam implantation.