Vibration based bridge scour evaluation: A data-driven method using support vector machines

Zhang, Zhiming,Sun, Chao,Li, Changbin,Sun, Mingxuan Techno-Press 2019 Structural monitoring and maintenance Vol.6 No.2

Bridge scour is one of the predominant causes of bridge failure. Current climate deterioration leads to increase of flooding frequency and severity and thus poses a higher risk of bridge scour failure than before. Recent studies have explored extensively the vibration-based scour monitoring technique by analyzing the structural modal properties before and after damage. However, the state-of-art of this area lacks a systematic approach with sufficient robustness and credibility for practical decision making. This paper attempts to develop a data-driven methodology for bridge scour monitoring using support vector machines. This study extracts features from the bridge dynamic responses based on a generic sensitivity study on the bridge's modal properties and selects the features that are significantly contributive to bridge scour detection. Results indicate that the proposed data-driven method can quantify the bridge scour damage with satisfactory accuracy for most cases. This paper provides an alternative methodology for bridge scour evaluation using the machine learning method. It has the potential to be practically applied for bridge safety assessment in case that scour happens.

On Peter Newmark: Translation theory and influence from the Chinese perspective

Shizhuo YANG & Zhiming SUN 한국통역번역학회 2012 FORUM Vol.10 No.2

A comparison of the fracture resistances of endodontically treated mandibular premolars restored with endocrowns and glass fiber postcore retained conventional crowns

Jing Guo,Zhiming Wang,Xuesheng Li,Chaoyang Sun,Erdong Gao,Hongbo Li 대한치과보철학회 2016 The Journal of Advanced Prosthodontics Vol.8 No.6

PURPOSE This in-vitro study aimed to evaluate the fracture resistances and failure modes of endodontically treated mandibular premolars restored with endocrowns and conventional post-core retained crowns. MATERIALS AND METHODS Thirty mandibular premolars were assigned into three groups (n=10): GI, intact teeth; GE, teeth with endocrowns; GC, teeth with conventional post-core supported crowns. Except for the teeth in group GI, all specimens were cut to 1.5 mm above the cementoenamel junction and endodontically treated. Both endocrowns and conventional crowns were fabricated from lithium-disilicate blocks using a CEREC 3D CAD/CAM unit. All specimens were subjected to thermocycling and then to 45° oblique compressive load until fracture occurred. The fracture resistance and failure mode of each specimen were recorded. Data were analyzed with one-way ANOVA and LSD Post Hoc Test (α=.05). RESULTS The fracture resistances of GE and GC were significantly lower than that of GI (P<.01), while no significant difference was found between GE and GC (P=.702). As of the failure mode, most of the specimens in GE and GC were unfavorable while a higher occurrence of favorable failure mode was presented in GI. CONCLUSION For the restoration of mandibular premolar, endocrown shows no advantage in fracture resistance when compared with the conventional method. Both of the two methods cannot rehabilitate endodontically treated teeth with the same fracture resistances that intact mandibular premolars have.

A comparison of the fracture resistances of endodontically treated mandibular premolars restored with endocrowns and glass fiber post-core retained conventional crowns

Guo, Jing,Wang, Zhiming,Li, Xuesheng,Sun, Chaoyang,Gao, Erdong,Li, Hongbo The Korean Academy of Prosthodonitics 2016 The Journal of Advanced Prosthodontics Vol.8 No.6

PURPOSE. This in-vitro study aimed to evaluate the fracture resistances and failure modes of endodontically treated mandibular premolars restored with endocrowns and conventional post-core retained crowns. MATERIALS AND METHODS. Thirty mandibular premolars were assigned into three groups (n=10): GI, intact teeth; GE, teeth with endocrowns; GC, teeth with conventional post-core supported crowns. Except for the teeth in group GI, all specimens were cut to 1.5 mm above the cementoenamel junction and endodontically treated. Both endocrowns and conventional crowns were fabricated from lithium-disilicate blocks using a CEREC 3D CAD/CAM unit. All specimens were subjected to thermocycling and then to $45^{\circ}$ oblique compressive load until fracture occurred. The fracture resistance and failure mode of each specimen were recorded. Data were analyzed with one-way ANOVA and LSD Post Hoc Test (${\alpha}=.05$). RESULTS. The fracture resistances of GE and GC were significantly lower than that of GI (P<.01), while no significant difference was found between GE and GC (P=.702). As of the failure mode, most of the specimens in GE and GC were unfavorable while a higher occurrence of favorable failure mode was presented in GI. CONCLUSION. For the restoration of mandibular premolar, endocrown shows no advantage in fracture resistance when compared with the conventional method. Both of the two methods cannot rehabilitate endodontically treated teeth with the same fracture resistances that intact mandibular premolars have.

Visible-Light-Driven Catalytic Disinfection of Staphylococcus aureus Using Sandwich Structure g-C₃N₄/ZnO/Stellerite Hybrid Photocatalyst

( Wanzhong Zhang ),( Caihong Yu ),( Zhiming Sun ),( Shuilin Zheng ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.6

A novel g-C₃N₄/ZnO/stellerite (CNZOS) hybrid photocatalyst, which was synthesized by coupled hydro thermal-thermal polymerization processing, was applied as an efficient visiblelight-driven photocatalyst against Staphylococcus aureus. The optimum synthesized hybrid photocatalyst showed a sandwich structure morphology with layered g-C₃N₄ (doping amount: 40 wt%) deposited onto micron-sized ZnO/stellerite particles (ZnO average diameter: ~18 nm). It had a narrowing band gap (2.48 eV) and enlarged specific surface area (23.05 ㎡/g). The semiconductor heterojunction effect from ZnO to g-C₃N₄ leads to intensive absorption of the visible region and rapid separation of the photogenerated electron-hole pairs. In this study, CNZOS showed better photocatalytic disinfection efficiency than g-C₃N₄/ZnO powders. The disinfection mechanism was systematically investigated by scavengerquenching methods, indicating the important role of H₂O₂ in both systems. Furthermore, h⁺ was demonstrated as another important radical in oxidative inactivation of the CNZOS system. In respect of the great disinfection efficiency and practicability, the CNZOS heterojunction photocatalyst may offer many disinfection applications.

Differential expression of heat shock protein 90, 70, 60 in chicken muscles postmortem and its relationship with meat quality

Zhang, Muhan,Wang, Daoying,Geng, Zhiming,Sun, Chong,Bian, Huan,Xu, Weimin,Zhu, Yongzhi,Li, Pengpeng Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.1

Objective: The aim of this study was to investigate the expression of heat shock protein (HSP) 90, 70, and 60 in chicken muscles and their possible relationship with quality traits of meat. Methods: The breast muscles from one hundred broiler chickens were analyzed for drip loss and other quality parameters, and the levels of heat shock protein (HSP) 90, 70, and 60 were determined by immunoblots. Results: Based on the data, chicken breast muscles were segregated into low (drip loss${\leq}5%$), intermediate (5%<drip loss<9.5%) and high (drip loss${\geq}9.5$) drip loss groups. The expression of HSP90 and HSP60 were significantly lower in the high drip loss group compared to that in the low and intermediate drip loss group (p<0.05), while HSP70 was equivalent in abundance in all groups (p>0.05). Conclusion: Results of this study suggests that higher levels of HSP90 and HSP60 may be advantageous for maintenance of cell function and reduction of water loss, and they could act as potential indicator for better water holding capacity of meat.

CNC tool path generation for freeform surface machining based on preferred feed direction field

Guanying Huo,Xin Jiang,Cheng Su,Zehong Lu,Yuwen Sun,Zhiming Zheng,Deyi Xue 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.5

This paper presents a novel method to generate three-axis CNC tool paths for machining freeform surfaces based on a preferred feed direction field. This research was initiated from a fluid dynamics behavior that the energy loss can be reduced when the streamlines of fluid and the small grooves on a surface are in the same directions. In this research, the fluid streamlines above the surface are defined by a collection of vectors. These vectors are regularized into a grid of vectors, and these regularized vectors are further projected onto the tangent planes of a grid of points on the surface to create the preferred feed direction field. Based on the parametric model of the surface, the vectors on the tangent planes of the surface are mapped into vectors in the parametric domain. A scalar function is constructed such that the isolines of this scalar function and the preferred feed direction vectors in the parametric domain are in the same directions. A group of isolines of the scalar function are identified and these isolines are mapped back onto the 3-D surface as the created tool paths considering the tolerance requirement. The developed method has been applied to generate the tool paths for machining surfaces of a compressor blade.