Research on Bridge Structural Health Assessment Based on Finite Element Analysis

In view of the content of bridge condition assessment and health monitoring, this paper is based on the finite element simulation analysis. The uncertain finite element model updating method based on sequential optimization strategy is studied, and the uncertain modal parameter data obtained by health monitoring system are applied to upgrade the uncertain finite element model of cable-stayed bridges, which provides a more accurate finite element model for subsequent reliability analysis. Firstly, the finite element dynamic analysis of the main span structure of the bridge is carried out, and the natural frequencies and modes are obtained. Then the measured natural frequencies of the structure are obtained by estimating the power spectrum of the dynamic monitoring data, and the theoretical values are compared with the measured ones. The dynamic characteristics of the modified two-stayed bridge finite element model are verified by the load test results. The results show that the modified finite element model can simulate the dynamic characteristics of the actual structure well. Most of the measured and calculated displacement increments were within the margin of error. The error is within 5%, which can accurately reflect the true stress state of the structure. The uncertainty model based on the sequential optimization strategy is simple and can be applied to the uncertainty of the finite element model of the actual bridge structure

Study on Modern Bridge Structure Health Monitoring System Based on Damage Identification

With the rapid growth of traffic, the loads\u27 design of many existing bridges can no longer meet the current vehicle load requirements, and the structural safety is seriously threatened. To ensure the structural safety of the bridge, it is necessary to monitor the bridge health and establish an early warning mechanism to prevent major accidents. The modern concrete bridge structure health monitoring based on damage identification proposed in this paper carried out principal component analysis of modern concrete bridges, and then this paper used principal component analysis (PCA) to locate the nonlinear damage source of the experimental model, which obtained the following conclusions. The maximum shear stress of the steel beam web is about 80 MPa，and the bulk stress of steel is reached at 7.5 MPa. Furthermore, to reduce the original data\u27s dimensionality, PCA effectively retains the characteristic information of the original data; empirical examples from external factor are presented. The major advantage of applying this framework is that the structural damage identification is simple and reliable with its advantages of dimensionality reduction, noise reduction, and exclusion of out-of-bounds interference factors

Short-term clinical outcomes and five-year survival analysis of laparoscopic-assisted transanal natural orifice specimen extraction versus conventional laparoscopic surgery for sigmoid and rectal cancer: a single-center retrospective study

BackgroundThe cosmetic benefits of natural orifice specimen extraction (NOSE) are easily noticeable, but its principles of aseptic and tumor-free procedure have caused controversy.MethodsWe conducted a retrospective analysis of the clinical data of patients who underwent laparoscopic-assisted transanal NOSE or conventional laparoscopic surgery (CLS) for sigmoid and rectal cancer at our hospital between January 2018 and December 2018. The study aimed to compare the general characteristics, perioperative indicators, postoperative complications, and five-year follow-up results between the two groups.ResultsA total of 121 eligible patients were enrolled, with 52 underwent laparoscopic-assisted transanal NOSE and 69 underwent CLS. There were no significant differences observed between the two groups in terms of gender, age, body mass index (BMI), TNM stage, etc. (P > 0.05). However, the NOSE group exhibited significantly shorter total incision length and longer operation time compared to the CLS group (P < 0.05). There were no statistically significant differences observed between the two groups in terms of positive rate of bacterial culture, incidence rates of intraabdominal infections or anastomotic leakage (P > 0.05). Furthermore, during follow-up period there was no statistically significant difference observed between these two groups concerning overall survival rate and disease-free survival outcomes (P > 0.05).ConclusionsThe management of surgical complications in CLS is exemplary, with NOSE presenting a sole advantage in terms of incision length albeit at the cost of prolonged operative time. Therefore, NOSE may be deemed appropriate for patients who place high emphasis on postoperative cosmetic outcomes

Off-line evaluation of indoor positioning systems in different scenarios: the experiences from IPIN 2020 competition

Every year, for ten years now, the IPIN competition has aimed at evaluating real-world indoor localisation systems by testing them in a realistic environment, with realistic movement, using the EvAAL framework. The competition provided a unique overview of the state-of-the-art of systems, technologies, and methods for indoor positioning and navigation purposes. Through fair comparison of the performance achieved by each system, the competition was able to identify the most promising approaches and to pinpoint the most critical working conditions. In 2020, the competition included 5 diverse off-site off-site Tracks, each resembling real use cases and challenges for indoor positioning. The results in terms of participation and accuracy of the proposed systems have been encouraging. The best performing competitors obtained a third quartile of error of 1 m for the Smartphone Track and 0.5 m for the Foot-mounted IMU Track. While not running on physical systems, but only as algorithms, these results represent impressive achievements.Track 3 organizers were supported by the European Union’s Horizon 2020 Research and Innovation programme under the Marie Skłodowska Curie Grant 813278 (A-WEAR: A network for dynamic WEarable Applications with pRivacy constraints), MICROCEBUS (MICINN, ref. RTI2018-095168-B-C55, MCIU/AEI/FEDER UE), INSIGNIA (MICINN ref. PTQ2018-009981), and REPNIN+ (MICINN, ref. TEC2017-90808-REDT). We would like to thanks the UJI’s Library managers and employees for their support while collecting the required datasets for Track 3. Track 5 organizers were supported by JST-OPERA Program, Japan, under Grant JPMJOP1612. Track 7 organizers were supported by the Bavarian Ministry for Economic Affairs, Infrastructure, Transport and Technology through the Center for Analytics-Data-Applications (ADA-Center) within the framework of “BAYERN DIGITAL II. ” Team UMinho (Track 3) was supported by FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope under Grant UIDB/00319/2020, and the Ph.D. Fellowship under Grant PD/BD/137401/2018. Team YAI (Track 3) was supported by the Ministry of Science and Technology (MOST) of Taiwan under Grant MOST 109-2221-E-197-026. Team Indora (Track 3) was supported in part by the Slovak Grant Agency, Ministry of Education and Academy of Science, Slovakia, under Grant 1/0177/21, and in part by the Slovak Research and Development Agency under Contract APVV-15-0091. Team TJU (Track 3) was supported in part by the National Natural Science Foundation of China under Grant 61771338 and in part by the Tianjin Research Funding under Grant 18ZXRHSY00190. Team Next-Newbie Reckoners (Track 3) were supported by the Singapore Government through the Industry Alignment Fund—Industry Collaboration Projects Grant. This research was conducted at Singtel Cognitive and Artificial Intelligence Lab for Enterprises (SCALE@NTU), which is a collaboration between Singapore Telecommunications Limited (Singtel) and Nanyang Technological University (NTU). Team KawaguchiLab (Track 5) was supported by JSPS KAKENHI under Grant JP17H01762. Team WHU&AutoNavi (Track 6) was supported by the National Key Research and Development Program of China under Grant 2016YFB0502202. Team YAI (Tracks 6 and 7) was supported by the Ministry of Science and Technology (MOST) of Taiwan under Grant MOST 110-2634-F-155-001

Off-Line Evaluation of Indoor Positioning Systems in Different Scenarios: The Experiences From IPIN 2020 Competition

Every year, for ten years now, the IPIN competition has aimed at evaluating real-world indoor localisation systems by testing them in a realistic environment, with realistic movement, using the EvAAL framework. The competition provided a unique overview of the state-of-the-art of systems, technologies, and methods for indoor positioning and navigation purposes. Through fair comparison of the performance achieved by each system, the competition was able to identify the most promising approaches and to pinpoint the most critical working conditions. In 2020, the competition included 5 diverse off-site off-site Tracks, each resembling real use cases and challenges for indoor positioning. The results in terms of participation and accuracy of the proposed systems have been encouraging. The best performing competitors obtained a third quartile of error of 1 m for the Smartphone Track and 0.5 m for the Foot-mounted IMU Track. While not running on physical systems, but only as algorithms, these results represent impressive achievements.Track 3 organizers were supported by the European Union’s Horizon 2020 Research and Innovation programme under the Marie Skłodowska Curie Grant 813278 (A-WEAR: A network for dynamic WEarable Applications with pRivacy constraints), MICROCEBUS (MICINN, ref. RTI2018-095168-B-C55, MCIU/AEI/FEDER UE), INSIGNIA (MICINN ref. PTQ2018-009981), and REPNIN+ (MICINN, ref. TEC2017-90808-REDT). We would like to thanks the UJI’s Library managers and employees for their support while collecting the required datasets for Track 3. Track 5 organizers were supported by JST-OPERA Program, Japan, under Grant JPMJOP1612. Track 7 organizers were supported by the Bavarian Ministry for Economic Affairs, Infrastructure, Transport and Technology through the Center for Analytics-Data-Applications (ADA-Center) within the framework of “BAYERN DIGITAL II. ” Team UMinho (Track 3) was supported by FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope under Grant UIDB/00319/2020, and the Ph.D. Fellowship under Grant PD/BD/137401/2018. Team YAI (Track 3) was supported by the Ministry of Science and Technology (MOST) of Taiwan under Grant MOST 109-2221-E-197-026. Team Indora (Track 3) was supported in part by the Slovak Grant Agency, Ministry of Education and Academy of Science, Slovakia, under Grant 1/0177/21, and in part by the Slovak Research and Development Agency under Contract APVV-15-0091. Team TJU (Track 3) was supported in part by the National Natural Science Foundation of China under Grant 61771338 and in part by the Tianjin Research Funding under Grant 18ZXRHSY00190. Team Next-Newbie Reckoners (Track 3) were supported by the Singapore Government through the Industry Alignment Fund—Industry Collaboration Projects Grant. This research was conducted at Singtel Cognitive and Artificial Intelligence Lab for Enterprises (SCALE@NTU), which is a collaboration between Singapore Telecommunications Limited (Singtel) and Nanyang Technological University (NTU). Team KawaguchiLab (Track 5) was supported by JSPS KAKENHI under Grant JP17H01762. Team WHU&AutoNavi (Track 6) was supported by the National Key Research and Development Program of China under Grant 2016YFB0502202. Team YAI (Tracks 6 and 7) was supported by the Ministry of Science and Technology (MOST) of Taiwan under Grant MOST 110-2634-F-155-001.Peer reviewe

Study on Bridge Structure Damage and Health Diagnosis Method Based on Health Monitoring

Due to the high cost of the bridge health monitoring system, only some large bridges are running the health monitoring system. This paper proposes methods for bridge structure damage and health diagnosis based on health monitoring. The establishment of various environmental load models, computer technology, and stochastic process analysis technology are equivalent to a large and complex system. The maximum longitudinal damage at the end fulcrum is about 24 mm, and the longitudinal damage does not exceed 6 kN. Moreover, the damage of the welding nail is caused by the temperature rise of 15 °C. The health monitoring of the bridge structure is ultimately to evaluate the health of the bridge structure. This paper analyses and evaluates the level of the cumulative damage of the bridge structure, which predicts the development trend of the damage, provides the bridge management department with timely status information, and provides bridge structure maintenance and management

Highly dispersed Fe-doped CoP nanoparticles encapsulated with P, N co-doped hollow carbon shell toward robust bifunctional oxygen electrocatalysis and rechargeable Li-O2 batteries

Engineering morphology and doping heteroatom are regarded as effective strategies for boosting the electrocatalytic performances of the transition-metal phosphides (TMPs). Herein, an efficient bifunctional electrocatalyst, the hollow core-shell nanostructured Fe–CoP@DPA composite consisting of Fe–CoP nanoparticles confined in a dopamine-derived carbon shell was synthesized through a one-step direct phosphorization method. With the merits of the unique hollow structure and efficient synergistic catalytic effect, the Fe–CoP@DPA delivers superior bifunctional ORR/OER activity. Density functional theory (DFT) calculation illustrates that Fe doping can upshift the d-band center of Fe–CoP@DPA, thereby enhancing the adsorption of intermediates during catalysis. The Li–O2 batteries with well-designed Fe–CoP@DPA cathode display an excellent long cycling stability of 282 cycles with a fixed capacity of 500 mAh g−1 at 200 mA g−1 and a high discharge specific capacity of 18208.5 mAh g−1 at 100 mA g−1. Rational designing the hollow nanostructured electrocatalyst with heteroatom doping will inspire the development of advanced cathode in Li–O2 batteries.</p

A short-term study of laparoscopic-dominant individualised levator ani resection in abdominoperineal resection: A retrospective investigation

Objective: The objective is to investigate if laparoscopic-dominant abdominoperineal resection (LDAPR) with individualised levator ani resection inhibits local recurrence (LR) and prolongs survival as compared to laparoscopic abdominoperineal resection (APR). Materials and Methods: Rectal cancer surgery cases were retrospectively identified from September 2014 to December 2019. LDAPR-treated group (55 patients) and the APR-treated group (71 patients) were included in the study. The operation time, circumferential resection margin (CRM), intraoperative tumor surgery (ITP), post-operative complications, the 2-year overall survival (OS) and LR were compared in the two groups. Results: The CRM and ITP were significantly reduced in the LDAPR as compared to the APR group (3.6% vs. 16.9%, t = 5.522, P = 0.019; 3.6% vs. 14.1%, t = 3.926, P = 0.048). In terms of post-operative complications, the incidence of urinary retention in LDAPR was significantly reduced than the APR group (10.9% vs. 25.4%, χ2 = 4.139, P = 0.041). Similarly, perineal pain at 6 months or 1 year after surgery was significantly down-regulated in LDAPR than in the APR group (72.7% vs. 88.7%, χ2 = 5.320, P = 0.021; 18.2% vs. 43.2%, χ2 = 8.288, P = 0.004). However, there was no statistically significant difference in the post-operative complications between the LDAPR and APR groups. Finally, LDAPR led to a significantly improved 2-year OS and a reduced LR compared to APR. Conclusion: LDAPR reduces CMR, ITP and LR and simplified the perineum operation, subsequently protecting the pelvic autonomic nerves. Compared to the conventional APR, LDAPR is a promising procedure worth adopting for rectal cancer treatment

Effects of Predominant Tree Species Mixing on Lignin and Cellulose Degradation during Leaf Litter Decomposition in the Three Gorges Reservoir, China

The aim of this study was to investigate the potential mixing effects on degradation of lignin and cellulose in mixed leaf litter from Pinus massoniana Lamb., Cupressus funebris Endl., and/or Quercus variabilis Bl., and elucidate the interactions with abiotic factors. The litter bag method was used in the field experiment, and the three predominant species in the Three Gorges Reservoir region were treated as single-, pair-, and tri-species combinations with equal proportions of litter mass. Lignin and cellulose losses in the litter treatments were measured, and the mixing effects were evaluated based on the sampling phase and decomposition period. At the end of the one-year decomposition period, mixing species increased lignin loss by 3.3% for the cypress + oak combination and cellulose loss by 3.9%, 1.8%, and 0.8% for the pine + oak, cypress + oak, and pine + cypress + oak combinations, respectively. The pine + oak and cypress + oak combinations exhibited greater lignin and cellulose loss than the tri-species mixture. Accelerated lignin degradation also apparently occurred in the pine + cypress combination as decomposition proceeded. Generalized linear models suggested that the investigated environmental factors (in terms of average temperature and cumulative precipitation) and changing litter quality (lignin, cellulose, and lignin/cellulose) had significant effects on nonadditive lignin loss, whereas only the changing litter quality factors significantly affected nonadditive cellulose loss. In summary, mixing two or three of the studied species alters cycling of recalcitrant substrates in plantations, and mixed planting with Quercus appears to strengthen both the lignin and cellulose degradation processes