Baseline-free damage detection method for beam structures based on an actual influence line

Ning-Bo Wang,Wei-Xin Ren,Tian-Li Huang 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.4

The detection of structural damage without a priori information on the healthy state is challenging. In order to address the issue, the study presents a baseline-free approach to detect damage in beam structures based on an actual influence line. In particular, a multi-segment function-fitting calculation is developed to extract the actual deflection influence line (DIL) of a damaged beam from bridge responses due to a passing vehicle. An intact basis function based on the measurement position is introduced. The damage index is defined as the difference between the actual DIL and a constructed function related to the intact basis, and the damage location is indicated based on the local peak value of the damage index curve. The damage basis function is formulated by using the detected damage location. Based on the intact and damage basis functions, damage severity is quantified by fitting the actual DIL using the least-square calculation. Both numerical and experimental examples are provided to investigate the feasibility of the proposed method. The results indicate that the present baseline-free approach is effective in detecting the damage of beam structures.

Surface and foam property of perfluoroalkyl polyoxyethylene ether phosphate salt in aqueous-ethanol system

Bo Ning,Yan Wang,Mi Zhang,Yanyun Bai,Xiumei Tai,Wanxu Wang,Guoyong Wang 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.94 No.-

Foam is used in manyfields with excellent performance. Moreover, disinfectants with ethanol as themain ingredient have increasingly been used in people's lives. However, the foam research of an ethanolwatermixed system is still in the initial stage. In this work, a perfluoroalkyl polyoxyethylene etherphosphate salt surfactant (FEP-Na) was synthesized through a new molecular design. The surfactant hasgood interfacial adsorption behavior in 50% ethanol-water mixing system, and the approximatelyspherical aggregates are observed in the volume phase of the solution. Moreover, FEP-Na showed goodfoaming property in 50% ethanol-water mixed solution. Interestingly, high concentration solutions withhigh surface activity have lower foam stability. And under the microscope, we see that the bubble burst isdominated by the phenomenon of coalescence. In this regard, we explain the mechanism of foamstability by electrostatic double layer theory and interfacial dilation rheology. It provides a new choice forthe synthesis of foaming agent in the ethanol-water mixed system at a concentration of 50%.

Application on Web Page Filtering Technology

Bo Shen,Lei Li,Ning-wei Wang 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.12

Web page filtering technology intends to filter out the large number of the repeated and theme-unrelated noise information and obtain useful information. Some web filtering methods cannot make full use of the layout and visual features. In view of the new mainstream “DIV+CSS” designing style of modern commercial web sites, this paper summarizes that elements laying in the same div blocks have common semantic features and proposed a DIV_FOREST model to represent the web pages. And in combination with the Vision-based Page Segmentation Algorithm, a DVPS Algorithm which considers both layout features and visual features was proposed to improve web page filtering efficiency.

Wavelet-based automatic identification method of axle distribution information

Ning-Bo Wang,Wei-Xin Ren,Zhi-Wei Chen 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.6

Accurately extracting the axle distribution information of a passing vehicle from bridge dynamic responses experiences a key and challenging step in non-pavement bridge weigh-in-motion (BWIM). In this article, the wavelet transformation is adopted and the wavelet coefficient curve is used as a substitute for dynamic response. The driving frequency is introduced and expanded to multi-axle vehicle, and the wavelet coefficient curve on specific scale corresponding to the driving frequency is confirmed to contain obvious axle information. On this basis, an automatic method for axle distribution information identification is proposed. The specific wavelet scale can be obtained through iterative computing, and the false peaks due to bridge vibration can be eliminated through cross-correlation analysis of the wavelet coefficients of two measure points. The integrand function that corresponds to the maximum value of the cross-correlation function is used to identify the peaks caused by axles. A numerical application of the proposed axle information identification method is carried out. Numerical results demonstrate that this method acquires precise axle information from the responses of an axle-insensitive structure (e.g., girder) and decreases the requirement of sensitivity structure of BWIM. Finally, an experimental study on a full-scale simply supported bridge is also conducted to verify the effectiveness of this method.

Examining the importance of discipline in Chinese schooling: an exploration in Shanghai, Hong Kong, Macao, and Taipei

Bo Ning 서울대학교 교육연구소 2019 Asia Pacific Education Review Vol.20 No.3

In the 2012 Programme for International Student Assessment, students from Shanghai, Hong Kong, Macao, and Taipei, where the classroom disciplinary climate of schools was relatively strict, were top performers in mathematics. In this study, two-level linear analyses showed that the classroom disciplinary climate of schools significantly affected student mathematics achievement in the four Chinese economies, indicating that school and economy-level inequality were related to the classroom disciplinary climate of schools. Additionally, residual analyses showed that students in different percentiles within economies, as well as students in the same percentiles of different economies, benefited or hindered differently from classroom disciplinary climate of schools, hinting at shrinking individual-level differences in student mathematics achievement. Most students in Shanghai and Hong Kong benefited from an orderly disciplinary climate in their schools, particularly medium and high performers in Shanghai, while most students in Taipei and Macao suffered from a disruptive disciplinary climate in their schools. Statistically, Taipei would replace Shanghai and top the four Chinese economies in student mathematics performance if all schools in the four had a disciplinary climate similar to the Organisation for Economic Co-operation and Development average.

Diagnostic Value of ¹⁸F-FDG PET/CT in Comparison to Bone Scintigraphy, CT and ¹⁸F-FDG PET for the Detection of Bone Metastasis

Liu, Ning-Bo,Zhu, Lei,Li, Ming-Huan,Sun, Xiao-Rong,Hu, Man,Huo, Zong-Wei,Xu, Wen-Gui,Yu, Jin-Ming Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

Purpose: To evaluate the diagnostic value of $^{18}F$-FDG PET/CT for detection of bone metastasis in comparison with the efficacies of $^{18}F$-FDG PET/CT, CT, $^{18}F$-FDG PET and conventional planar bone scintigraphy in a series of cancer patients. Methods: Five hundred and thirty patients who underwent both $^{18}F$-FDG PET/CT and bone scintigraphy within 1 month were retrospectively analyzed. The skeletal system was classified into 10 anatomic segments and interpreted blindly and separately. For each modality, the sensitivity, specificity, accuracy, PPV and NPV were calculated and the results were statistically analyzed. Results: Bone metastases were confirmed in 117 patients with 459 positive segments. On patient-based analysis, the sensitivity, specificity, accuracy, PPV and NPV of $^{18}F$-FDG PET/CT were significantly higher than bone scintigraphy, CT and $^{18}F$-FDG PET (P<0.05). On segment-based analysis, the sensitivity of CT, bone scintigraphy, $^{18}F$-FDG PET and $^{18}F$-FDG PET/CT were 70.4%, 89.5%, 89.1% and 97.8%, respectively (P<0.05, compared with $^{18}F$-FDG PET/CT). The overall specificity and accuracy of the four modalities were 89.1%, 91.8%, 90.3%, 98.2% and 90.3%, 90.9%, 89.8%, 98.0%, respectively (P<0.05, compared with $^{18}F$-FDG PET/CT). The PPV and NPV were 89.8%, 87.6%, 85.6%, 97.2% and 85.6%, 93.2%, 92.8%, 98.6%, respectively. Three hundred and twelve lesions or segments were presented as lytic or sclerotic changes on CT images at the corresponding sites of increased $^{18}F$-FDG uptake. In lytic or mixed lesions, the sensitivity of $^{18}F$-FDG PET/CT and $^{18}F$-FDG PET were better than bone scintigraphy, while in osteoblastic lesions bone scintigraphy had a similar performance with $^{18}F$-FDG PET/CT but better than $^{18}F$-FDG PET alone. Conclusion: Our data allow the conclusion that $^{18}F$-FDG PET/CT is superior to planar bone scintigraphy, CT or $^{18}F$-FDG PET in detecting bone metastasis. $^{18}F$-FDG PET/CT may enhance our diagnosis of tumor bone metastasis and provide more information for cancer treatment.

한국어와 중국어의 사동구조 대조 -사동화 내포 구조를 중심으로-

왕녕박 ( Wang Ning-bo ),박소영 ( Park So-young ) 서강대학교 언어정보연구소 2016 언어와 정보 사회 Vol.29 No.-

This paper presents a comparative syntactic analysis of Korean and Chinese causatives, based on Pylkkanen(2002)`s parametric theory on causatives. Both languages are identified as voice-splitting languages, in which a Cause head, responsible for introducing a causing event, projects independently from a Voice head introducing an external argument. Also, Korean and Chinese have three types of causatives, which vary depending on the sizes of clauses that can be embedded by a Cause head, namely, a root phrase, a vP, and a phasal VoiceP structure. The presented analysis can be supported by evidence from the retainability of idiomatic interpretations of idioms depending on voice alternations.

The complete mitochondrial genome of fall armyworm Spodoptera frugiperda (Lepidoptera:Noctuidae)

Bo-Ping Tang,Qiu-Ning Liu,Xin-Yue Chai,Dan-Dan Bian,Bao-Ming Ge,Chun-Lin Zhou 한국유전학회 2016 Genes & Genomics Vol.38 No.2

The mitochondrial genome (mitogenome) can provide important information for understanding molecular evolution and phylogenetic analyses. The complete mitogenome of Spodoptera frugiperda (Lepidoptera:Noctuidae) was determined to be 15,365 bp in length and has the typical gene order found in Noctuidae mitogenomes, it includes 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and a A?T-rich region. The nucleotide composition was biased toward A?T nucleotides (81.09 %) and the AT skew of this mitogenome was slightly positive (0.004). All PCGs were initiated by ATN codons, except for cytochrome c oxidase subunit 1 (cox1) gene which was initiated by CGA. Eight of the 13 PCGs have the incomplete termination codon, T or TA. All the tRNA genes displayed the typical clover-leaf structure of mitochondrial tRNAs, with the exception of trnS1 (AGN). The A?T-rich region was 328 bp in length and consisted of several features common to the Noctuidae insects. Phylogenetic analysis showed that the S. frugiperda was within the Noctuidae.

Experimental and numerical analysis of unsteady pressure pulsation in a centrifugal pump with slope volute

Ning Zhang,Minguan Yang,Bo Gao,Zhong Li,Dan Ni 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.10

This study experimentally and numerically investigates the unsteady flow in a centrifugal pump with special slope volute under variousconditions to illustrate the detailed flow structures and pressure pulsation within the model pump. Whole flow passage is consideredduring the numerical simulation; pressure pulsation signals are extracted using nine fast-response pressure transducers. The Root meansquare (RMS) method is introduced to deal with the discrete components at fBPF of the different monitoring points along the volute casing,which is an effective attempt to evaluate the overall pulsating level of the model pump. Results show that numerical method canpredict the components at fBPF effectively; however, it has limited ability in capturing noise frequencies motivated by unsteady separateflow and non-linear interaction effect. Around the nominal flow rate, the predicted amplitudes at fBPF agree well with the experimentalresults, showing larger difference at the off-design conditions. To predict the pulsating level of the components at fBPF, two fitted equationsof the RMS values versus the flow rate and specific speed are carried out, which would be very helpful in evaluating the pressurepulsation level in the centrifugal pump.

A Novel Method for Thermal Analysis of MF Transformers with Hollow Windings

Bo Zhang,Ning Yan,Naisheng Liu 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

One of the key problems in the research and development of high-power electronic transformer is the thermal analysis of high-frequency or medium frequency transformer under non-sinusoidal load. At present, there is a lack of a convenient and effective method. Taking the thermal problem of an medium frequency transformer with a hollow conductor structure as an example, this paper presents an analysis method suitable for researchers. Firstly, based on the finite element model, the loss of hollow winding is studied by numerical analysis. Then, based on the similarity principle, the equivalent reduction method for calculating the core loss of medium frequency transformer is presented. Finally, the measurement data of the magnetic properties of the transformer core and the measurement data of the transformer loss under the medium frequency excitation are given. The complete research work can provide a method for the thermal analysis of high frequency or medium frequency transformer.