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7 results on '"Liu, Longcan"'

1. Multiscale Convolutional Neural Network With Feature Alignment for Bearing Fault Diagnosis

Author

Junbin Chen, Ruyi Huang, Weihua Li, Kun Zhao, Wei Wang, and Liu Longcan

Subjects
Computer science, business.industry, Deep learning, 020208 electrical & electronic engineering, Feature extraction, Pattern recognition, 02 engineering and technology, Fault (power engineering), Convolutional neural network, Convolution, Kernel (image processing), Feature (computer vision), Robustness (computer science), 0202 electrical engineering, electronic engineering, information engineering, Artificial intelligence, Electrical and Electronic Engineering, business, Instrumentation
Abstract

In recent years, deep learning methods, especially convolutional neural network (CNN), have received extensive attentions and applications in fault diagnosis. However, recent studies have shown that the shift-invariance of CNN is not good enough, resulting in fragile feature extraction and sharp reduction in model performance when the shift occurs in the input. To improve the shift-invariance of CNN, considering the periodic characteristics of vibration signals, a multiscale CNN with feature alignment (MSCNN-FA) is proposed for bearing fault diagnosis under different working conditions. First, by analyzing the operating principles of the convolutional layer and pooling layer, a feature alignment module including single-stride convolution layer, adaptive max-pooling layer, and global average pooling layer is designed to obtain aligned features. Next, to extract shift-invariant robust features from vibration signals, a multiscale convolution strategy is utilized, and a feature-aligned multiscale feature extractor is constructed. Finally, a classifier composed of fully connected (FC) layers is constructed for bearing fault diagnosis. The effectiveness of the method is verified by a rolling bearing experiment, which outperforms other related existing CNN-based methods in terms of diagnosis accuracy and feature robustness.

Published
2021

2. Deep Feature-aligned Convolutional Neural Network for Machinery Fault Diagnosis

Author

Ruyi Huang, Weihua Li, Junbin Chen, and Liu Longcan

Subjects
Vibration, business.product_category, Computer science, business.industry, Robustness (computer science), Bearing vibration, Feature extraction, Pattern recognition, Artificial intelligence, business, Convolutional neural network, Machine tool
Abstract

Convolutional neural network (CNN) has been witness to remarkable development and application over the past decade in the field of fault diagnosis. However, it has an obvious limitation that the property of shift-invariance in CNN is not robust enough, resulting in insufficient robustness of feature extraction, which is manifested by fluctuant prediction accuracy and confidence. Aiming at overcoming such limitation, in this paper, a deep feature alignment method is proposed for extracting aligned features from periodical vibration signals, and applied for the fault diagnosis of rotating machinery. First, considering the periodicity of bearing vibration signals, a feature-aligned CNN (FACNN) architecture is constructed to improve the shift-invariance of CNN. Second, the performance of the proposed structure is compared with the traditional CNN in three aspects: diagnosis accuracy, prediction confidence and feature robustness. Finally, a bearing fault diagnosis case was carried out on an experimental setup of machine tool to validate the effectiveness of FACNN. Experimental results have shown the FACNN outperforms the traditional CNN in the task of fault diagnosis for rotating machinery.

Published
2020

5. [Clinical research of sideburn reconstruction with expanded island scalp flap based on parietal branch of superficial temporal vessel].

Author

Liu L, Liu Y, Zang M, Zhu S, Chen B, and Li S

Subjects
Adolescent, Adult, Child, Child, Preschool, Face surgery, Fascia, Female, Humans, Male, Skin Transplantation, Young Adult, Plastic Surgery Procedures, Scalp, Surgical Flaps
Abstract

Objective: To explore the feasibility and effectiveness of sideburn reconstruction using the expanded island scalp flap based on the parietal branch of the superficial temporal vessel., Methods: Between February 2012 and April 2015, 7 patients underwent sideburn reconstruction. There were 3 males and 4 females with an average age of 15 years (range, 4-44 years). The etiologies included burn injury in 3 cases, trauma in 1 case, radiation therapy in 1 case, and congenital melanocytic nevus in 2 cases. The size of the sideburn defects ranged from 5.0 cm×3.5 cm to 16.0 cm×10.0 cm. At the first-stage, according to the sideburn defect, a tissue expander of the appropriate size was inserted beneath the superficial temporal fascia which containing the parietal branch of the superficial temporal vessel. Postoperatively, regular saline injection was commenced. After 3-6 months of the first-stage surgery, the expander was adequately inflated. While the second-stage surgery was performed, the lesion was excised and the tissue expander removed. The expanded island scalp flap based on the parietal branch of the superficial temporal vessel was harvested and advanced towards the defect of the sideburn according to the contralateral normal one, and the size of flap ranged from 8 cm×3 cm to 17 cm×11 cm. The donor site was closed primarily., Results: All flaps survived and the wound and donor sites were healed primarily without any complication. All patients were followed up 1-36 months (mean, 9.8 months). The profile, hair density, and hair direction of the new sideburn were similar to the contralateral sideburn. In 1 patient, the reconstructed sideburn was a little larger than the contralateral normal one. After laser hair removal, the patient was satisfied with the appearance., Conclusion: The expanded island scalp flap based on the parietal branch of the superficial temporal vessel provides an effective option for the sideburn reconstruction, which presents with the similar appearance to the contralateral one.

Published
2017
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6. [DESIGN AND CLINICAL APPLICATIONS OF DISTALLY BASED ANTEROMEDIAL THIGH FLAPS PEDICLED WITH PERFORATING VESSELS FROM RECTUS FEMORIS BRANCH].

Author

Liu L, Liu Y, Zang M, Zhu S, Chen B, and Li S

Subjects
Adolescent, Adult, Child, Child, Preschool, Female, Humans, Male, Middle Aged, Soft Tissue Injuries, Surgical Flaps, Thigh, Young Adult, Quadriceps Muscle transplantation, Plastic Surgery Procedures, Skin Transplantation
Abstract

Objective: To explore the feasibility and technical essentials of soft tissue defect reconstruction of the lower extremity using the distally based anteromedial thigh flap (dAMT) pedicled with perforating vessels from rectus femoris branch., Methods: Between July 2008 and December 2015, 6 patients underwent defect reconstruction of the lower extremity using the dAMT flap pedicled with perforating vessels from rectus femoris branch. There were 4 males and 2 females with an average age of 34 years (range, 4-55 years). The etiologies included liposarcoma in 1 case, malignant fibrous histocytoma in 1 case, post-burn scar contracture around the ankle in 1 case, and post-burn scar contracture around the knee in 3 cases. The disease duration ranged from 3 to 28 months (mean, 13 months). After resection of lesion tissues, the defect size ranged from 13 cm×7 cm to 24 cm×12 cm. The flap size ranged from 15 cm×8 cm to 24 cm×12 cm. The length of the pedicle ranged from 10 to 25 cm (mean, 19.8 cm). The distance from the flap pivot point to the superolateral border of the patella ranged from 8 to 13 cm (mean, 11.3 cm). The donor sites were directly sutured., Results: All flaps survived postoperatively without any complications. All wounds at the donor and the recipient sites healed primarily. The patients were followed up from 5 to 36 months (mean, 17.8 months). The color, texture, and thickness of the flaps were similar to those of the surrounding skin. No tumor recurrence was observed. The range of motion of flexion and extension of the joint were greatly improved in the patients with scar contracture., Conclusions: If the rectus femoris branch gives off cutaneous branch to the anteromedial thigh region and arises from the descending branch of the lateral circumflex femoral artery, a dAMT flap could be raised to reconstruct soft tissue defects of the lower extremity.

Published
2016
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7. [Reconstruction of extensive soft-tissue defects at the upper extremities using the pre-expanded paraumbilical perforator flaps].

Author

Zhu S, Liu Y, Zang M, Chen B, Ding Q, Zhang J, and Liu L

Subjects
Esthetics, Forearm surgery, Humans, Upper Extremity surgery, Perforator Flap, Plastic Surgery Procedures methods, Soft Tissue Injuries surgery
Abstract

Objective: To explore the feasibility and technique of reconstruction of extensive soft-tissue defects at upper extremities using the pre-expanded paraumbilical perforator (PUP) flaps., Methods: Pre-expanded PUP flap was used to reconstruct large soft-tissue defect at the upper extremity according to the size, shape, and location of the defect in a multiple-staged procedure., Results: From Sept.2009 to Sept.2015,81 patients underwent defect reconstruction using the pre-expanded PUP flaps.93 preexpanded PUP flaps were used. Unilateral flap was used in 70 patients. Bilateral flaps were used to reconstruct the circumferential forearm defects in eight patients (16 flaps).Bilateral flaps were used to reconstruct bilateral forearm defects in three patients (6 flaps).The size of the flaps ranged from 8 cm ×6 cm to 40 cm × 15 cm. Small-sized distal flap necrosis occurred in five patients after division of the proximal pedicle of the flap. The patients were followed up for 1 to 5 years (average 3.5 years) with satisfactory functional and aesthetic outcomes. Dysfunction of the shoulder and elbow joints was not noticed postoperatively., Conclusions: The pre-expanded paraumbilical perforator flap provides a valuable option for different defects reconstruction at the upper extremity.

Published
2016

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