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Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To quickly and accurately predict the compressive strength of concrete, a prediction model is established using deep learning technology. The model is automatically optimized and adjusted using the Bayesian optimization algorithm, and the prediction results are analyzed by combining with the Shapley Additive explanations (SHAP) interpretable method, which overcomes the problem of the “black box” of the prediction model. The deep learning model is used to mine the potential law between each input feature parameter and compressive strength, the importance of the parameters on the compressive strength prediction results and the influence law is analyzed by visualizing the SHAP values of the input feature parameters. The results show that the constructed deep learning model outforms other traditional models. The SHAP analysis results are consistent with the experimental results, and the model better reflects the complex nonlinear relationship among the characteristic parameters， which can provide the basis and reference for the engineering design of concrete materials. [ABSTRACT FROM AUTHOR]

Copyright of Science Technology & Engineering is the property of Chinese Society of Technology Economics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In view of the matching problem between objects and mirrors in images, the RNFA(Relative Number of False Alarms)edge chain detection method is introduced to obtain richer line segments. An improved LBD(Line Band Descriptor) algorithm is proposed for constructing local invariant feature descriptors, and initial matching pairs are obtained by comparing local invariant feature descriptors. The screening of the global projection angle is adopted and the false matches in the initial matching pairs are eliminated fitting the projection center line. After the selection of the global projection angle and the fitting of the projection median are completed, the screening of the local invariant feature descriptor threshold is relaxed to obtain more matching pairs and improve the recall rate. The experimental results of image set simulation show that the designed algorithm can better identify line segments in the weaker texture regions and obtain more matching pairs on the basis of the guaranteed performance of the original algorithm, which can improve the correct matching rate by about 5% and achieve a recall rate of over 90%. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In view of the problem of trajectory planning of multiple UAVs in complex environments, a multi-UAV trajectory planning algorithm based on formation changes is proposed. Based on the topology of pilot-following UAV, a cost function with time and range as the metrics is designed to solve the optimal formation rendezvous point. The improved Informed-RRT* algorithm is used to solve the asymptotic optimal track of the leader, and the track planning and obstacle avoidance of the follower is realized by combining the formation change strategy. On the basis of defining formation variation, path length ratio, and heading stability performance indicators, simulation experiments are carried out and the generated tracks are evaluated and compared. The simulation results show that the UAV formation can achieve trajectory planning and obstacle avoidance in complex environments, and at the same time plan the optimal trajectory planning for the follower, which is less than 1% away from the optimal trajectory length of the leader, which improves the practicality and effectiveness of the algorithm. [ABSTRACT FROM AUTHOR]

The swarm system is a specific system composed of multiple agents interacting with information locally. Part of agents’ state is difficult to available or even undetectable in practical applications, and the relationship between agents can be cooperative or competitive. In this study, a bipartite formation control protocol for distributed swarm systems based on output feedback is designed under the signed network topology. This strategy takes the output state between neighboring agents as the feedback information without relying on the global information of the communication topology. Considering that the real systems are often affected by external disturbances, some sufficient conditions that the control protocol can guarantee the system error is finally uniformly bounded are established based on Lyapunov stability theory. After analyzing the robustness of the protocol, the residual set of the final uniformly convergent errors is given. According to the designed control protocol and formation conditions, simulation is carried out to verify the effectiveness of the protocol, and the time for the system to reach stability under different initial ranges is given. [ABSTRACT FROM AUTHOR]

To investigate the changes of platelet⁃lymphocyte ratio（PLR）in obstructive sleep apnea hypopnea syndrome （OSAHS）patients with acute ischemic stroke and the clinical value of PLR. Methods：The case data of 155 patients with OSAHS were retrospectively analyzed. According to the presence or absence of acute ischemic stroke,patients were divided into simple OSAHS group（group A,n=93）and OSAHS combined with acute ischemic stroke group（group B,n=62）. According to apnea hypopnea index （AHI）,patients in group B were divided into three grades：mild,medium and severe. Clinical data of the two groups were collected and SPSS 25.0 software was used to analyze the correlation between the two groups and the efficacy of PLR in predicting acute ischemic stroke in OSAHS patients. Results：①There were significant differences in LYM,PLT,NEUT,neutrophil lymphocyte ratio（NLR）, PLR,TS90% and AHI between the two groups（P < 0.05）. ②PLR was positively correlated with AHI in group B（P=0.000）. ③ Logistics analysis showed that PLR was an independent risk factor for acute ischemic stroke in OSAHS patients（P=0.000）. ④ROC curve analysis showed that the best cut⁃off value of serum PLR for predicting acute ischemic stroke in OSAHS patients was 130.79,and the area under the curve was 0.888（95%CI：0.832⁃0.945）. Conclusions：High serum PLR is positively correlated with AHI in OSAHS patients with acute ischemic stroke,and PLR may be an independent predictor of acute ischemic stroke in OSAHS. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science Technology & Engineering is the property of Chinese Society of Technology Economics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The homogeneous swarm system is limited in function because of its single component. The individual composition of the heterogeneous cluster system is diverse， so the functions of the homogeneous cluster system can be extended. In view of the problem of formation tracking control in heterogeneous swarm system， based on leader-follower model， a distributed PI formation tracking control protocol is designed under the directed communication topology. The expected time-varying formation is designed， and the followers keep the expected formation while tracking the leader， so that all the agents in the system can reach the expected position. Considering that the real system is often affected by the external unknown disturbance and some uncertain factors， based on the Lyapunov stability theory， some sufficient conditions are given to ensure the tracking error of the system to be uniformly bounded， and the robustness analysis is carried out. The simulation verification is carried out according to the designed control protocol and control conditions. The results show that the designed PI formation tracking control strategy can effectively solve the formation tracking control problem of heterogeneous cluster systems. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Computer Engineering & Applications is the property of Beijing Journal of Computer Engineering & Applications Journal Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Medical Equipment Journal is the property of Chinese Medical Equipment Journal Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wind turbines are generally placed in harsh environments, and their pitch actuators are prone to failure. Aiming at the problem of pitch actuator failure in a class of wind turbine systems with unknown but bounded interference and noise, a set-member unknown input observer is designed to detect and separate pitch actuator failures. The aerodynamic mechanism and modern identification principles are used to establish the wind turbine system model, and the disturbance in the system is decoupled by optimizing the design of the unknown input observer, and the interval envelope of the residual error when the fault is not considered in the centrosymmetric polytope estimation is used as the upper and lower parts of the residual error estimation. Dynamic threshold for state estimation. Based on the above, a strategy for fault diagnosis using a set of set-membership unknown input observers is proposed. The simulation results show that during the experiment, the set-member unknown input observer designed in this paper can accurately diagnose the time and time of sudden and slow time-varying faults of the third-order and fifth-order linear systems of the wind turbine pitch actuator. position, which proves the effectiveness of the proposed fault diagnosis strategy. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of South China Agricultural University is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The goal of visual SLAM technology is to build a more complete map and estimate a more accurate camera pose. To construct a more detailed and complete 3D map, a semi-dense 3D reconstruction ORB-SLAM algorithm with improved ORB feature matching is proposed to realize the construction of a sparse 3D point cloud map of the environment. On the basis of the ORB-SLAM algorithm, a semi-dense mapping thread is added to establish a semi-dense 3D point cloud map. Then, the scale invariance of SURF feature matching algorithm is used to improve ORB feature matching. Simulation experiments in the TUM RGBD datasets reveal that the 3D map established by the improved ORB-SLAM algorithm can more intuitively exhibit the contours of objects in the environment when compared with the ORB-SLAM algorithm, and the feature matching accuracy is increased. Finally, the consistency of the algorithm is verified by experiments in two datasets. [ABSTRACT FROM AUTHOR]

Copyright of Urban Architecture & Development is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electronic Science & Technology is the property of Electronic Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In practical applications, it is necessary for multiple agents lo work together according lo the desired formation. At this time, the multi - agents system is heterogeneous. In view of this problem, this study investigates the time - varying formation control problem of heterogeneous nonlinear multi - agents system based on the theory of consensus. A formation control strategy is designed by using the nonlinear parameter decomposition method to represent the heterogeneous nonlinear terms in a unified form. An adaptive time - varying formation control strategy is designed based on adaptive strategy and stale information feedback using the leader - follower method under directed topology, and the stability of the control strategy is proved by using Lyapunov stability theory. The simulation carried out in the case of one leader with three followers shows that the system is basically stable when the time is 40 s, and the system is stable and formed the desired time - varying formation when the time is 60 s, which verifies the effectiveness of the control strategy. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhejiang University (Science Edition) is the property of Journal of Zhejiang University (Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve the problem of obstacle avoidance and path planning when the small drone is insufficient in indoor light. In this paper, an indoor map construction system of UAV based on depth camera is designed and implemented. The pixhawk control board and low-cost embedded structure optical depth camera hardware platform are used to provide indoor environmental information for obstacle avoidance and path planning. Anti-sensor model algorithm is adopted, the information provided by the depth camera, pose sensor to filter are utilized to select and process effective obstacle information. A 3D map of the interior is established, and the depth camera acquires the description information of the obstacle point cloud by means of laser scanning. The position sensor is used to acquire the height information of the drone. The experimental results show the system could quickly acquire indoor maps, and the accuracy of the obstacles is relatively high, and it is not affected by light. The proposed system can be widely used for indoor navigation of drones, and realizes an indoor drone map construction system that does not rely on external light sources. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China Normal University (Natural Science Edition) / Huanan Shifan Daxue Xuebao (Ziran Kexue Ban) is the property of Journal of South China Normal University (Natural Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals Engineering is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Computer Engineering & Applications is the property of Beijing Journal of Computer Engineering & Applications Journal Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Zhejiang University (Science Edition) is the property of Journal of Zhejiang University (Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Medical Equipment Journal is the property of Chinese Medical Equipment Journal Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

目的 评估腹腔镜技术在超低位直肠癌根治术中的应用效果。方法 2017 年1月至 2018 年11月共有 108 例患 者在该院行超低位直肠癌根治术。根据患者手术类型分为腹腔镜组 (77 例) 和传统开腹组 (31 例)。对比两组临床资料。 结果 腹腔镜组患者中 2 例中转开腹。腹腔镜组患者术中出血量要显著低于传统开腹组, 但手术时间较传统开腹组显著延长, 术 后并发症发生情况明显优于传统开腹组,其术后胃肠功能、胃管拔出、引流管拔出时间明显较传统开腹组缩短, 保肛率显著高于开 腹组, 差异均有统计学意义 (P <0.05)。两组中各有1例发生了吻合口瘘, 均保守治疗好转。腹腔镜组淋巴结清扫数目与传统开 腹组比较, 差异无统计学意义 (P =0.274)。两组均未发生输尿管损伤、排尿障碍、大便失禁。结论 腹腔镜下超低位直肠根治术 与传统开腹术比较, 其在术后并发症率和胃肠功能恢复方面占显著优势, 且其保肛率明显高于传统开腹术。在肿瘤根治性和安全 性方面, 两者效果近似。 [ABSTRACT FROM AUTHOR]

Copyright of Chinese Medical Equipment Journal is the property of Chinese Medical Equipment Journal Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mechanical & Electrical Engineering is the property of Mechanical & Electrical Engineering Magazine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Progress in Modern Biomedicine is the property of Publishing House of Progress in Modern Biomedicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Basic Sciences Journal of Textile Universities / Fangzhi Gaoxiao Jichu Kexue Xuebao is the property of Basic Sciences Journal of Textile Universities and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective To analyze the relationship between the expression of stem cell markers Sox2，OCT4，CD44 andβ-catenin in gastric cancer tissue and the recurrence and metastasis after operation，in order to provide reference for the risk assessment and prediction of gastric cancer.Methods 132 cases of gastric cancer admitted to central hospital of Chongq- ing Three Gorges from March 2011 to March 2014 were selected as research subjects.The expression of Sox2，OCT4，CD44 and β-catenin in gastric cancer specimens were detected，and the effects of these stem cell markers on postoperative recurrence and metastasis of gastric cancer were analyzed. Results In the 132 specimens，74 cases were positive for Sox2（56.06%），58 cases were positive for OCT4（43.94%），78 cases were positive for CD44（59.09%），and 70 cases were positive for β - catenin （53.03%）.The positive rate of Sox2 in gastric cancer tissues of patients with different age，lymph node metastasis and degree of differentiation was statistically significant（P<0.05）.The positive rate of OCT4 in gastric cancer tissues of patients with different TNM stages was statistically significant（P<0.05）.The positive rate of CD44 in gastric cancer tissues of patients with different histological grade，tumor diameter，vascular infiltration，lymph node metastasis and TNM stages was statistically significant（P< 0.05）.The positive rate of β-catenin in gastric cancer tissues of patients with different lymph node metastasis and TNM stages was statistically significant（P<0.05）.During the follow-up period，105 of 132 cases had recurrence and metastasis，and the inci- dence was 79.55%.With the increase of the positive rate of stem cell markers in patients with gastric cancer，the incidence of re- currence and metastasis gradually increased ，and the difference was statistically significant（P<0.05）.Conclusion The mark- ers of stem cells in gastric cancer are related to the clinicopathological features of the patients.Early detection of stem cell mark- ers in gastric cancer tissue is expected to provide reference for the risk assessment of recurrence and metastasis. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhejiang University. Humanities & Social Sciences / Zhejiang Daxue Xuebao is the property of Zhejiang University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Research & Exploration in Laboratory is the property of Research & Exploration in Laboratory and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Computer Engineering & Science / Jisuanji Gongcheng yu Kexue is the property of Computer Engineering & Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Architectural Design & Research is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)