Chunjie Wang

Beihang University

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Jianfang Liu

Columbia University

Ning Lang

Peking University

Huishu Yuan

Peking University

Hanqiang Ouyang

Peking University

Jianzhong Ding

Beihang University

Quguang Li

Soochow University

Liang Jiang

Peking University Third Hospital

Zhuang Liu

Soochow University

Tianyuan Qi

Beihang University

Xueao Liu

North China University of Technology

Cooperative Institutions

Universitat de Barcelona

Max Planck Institute for Physics

Ludwig-Maximilians-Universität München

Johannes Gutenberg University Mainz

Technical University of Munich

Halbleiterlabor of the Max-Planck-Society

Charles University

Instituto de Física de Cantabria

University of Bonn

Deutsches Elektronen-Synchrotron DESY

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Application and Development of Drilling and Completion of the Ultrashort-Radius Radial Well by High Pressure Jet Flow Techniques

International Oil and Gas Conference and Exhibition in China (2000)

Yonghe Li Chunjie Wang Lianhai Shi Guo Wei-yi

Abstract Ultrashort radius radial well drilling and completion technique by high pressure jet flow is referred to as the Ultrashort radius (0.3meter) radial horizontal well drilling and completion techniques. It can be applied both in new and old wells. Its main technique is to use high pressure jet flow energy, given by a special high pressure jet tube, to penetrate and elongate a number of lateral well bores radiated from the main well bore in the same layer (or different layer) so as to expose the pay zone as much as possible and increases the EOR. This paper has described three key parts of high pressure jet flow technique for ultrashort radius radial well drilling and completion: big diameter underreaming technique; design principle of diverting system; and option of well completion methods. And introduces whole process and key parts of this technique combined with its application results in Jin Well#04–19 and Jin Well#38–303 of Liaohe Oilfield. This paper has also briefly depicted the future development of this technique in the Oilfield and its main problems must be resolved later, as well as its economy and feasibility.

10.2118/64756-ms

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Citations (33)

One-Stage Deep Edge Detection Based on Dense-Scale Feature Fusion and Pixel-Level Imbalance Learning

arXiv (Cornell University) (2022)

Dawei Dai Chunjie Wang Shuyin Xia Yingge Liu Guoyin Wang

Edge detection, a basic task in the field of computer vision, is an important preprocessing operation for the recognition and understanding of a visual scene. In conventional models, the edge image generated is ambiguous, and the edge lines are also very thick, which typically necessitates the use of non-maximum suppression (NMS) and morphological thinning operations to generate clear and thin edge images. In this paper, we aim to propose a one-stage neural network model that can generate high-quality edge images without postprocessing. The proposed model adopts a classic encoder-decoder framework in which a pre-trained neural model is used as the encoder and a multi-feature-fusion mechanism that merges the features of each level with each other functions as a learnable decoder. Further, we propose a new loss function that addresses the pixel-level imbalance in the edge image by suppressing the false positive (FP) edge information near the true positive (TP) edge and the false negative (FN) non-edge. The results of experiments conducted on several benchmark datasets indicate that the proposed method achieves state-of-the-art results without using NMS and morphological thinning operations.

Feature (linguistics)

Benchmark (surveying)

10.48550/arxiv.2203.09387

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Generation of Vertebra Micro-CT-like Image from MDCT: A Deep-Learning-Based Image Enhancement Approach

Tomography (2021)

Dan Jin Han Zheng Qingqing Zhao Chunjie Wang Mengze Zhang

This paper proposes a deep-learning-based image enhancement approach that can generate high-resolution micro-CT-like images from multidetector computed tomography (MDCT). A total of 12,500 MDCT and micro-CT image pairs were obtained from 25 vertebral specimens. Then, a pix2pixHD model was trained and evaluated using the structural similarity index measure (SSIM) and Fréchet inception distance (FID). We performed subjective assessments of the micro-CT-like images based on five aspects. Micro-CT and micro-CT-like image-derived trabecular bone microstructures were compared, and the underlying correlations were analyzed. The results showed that the pix2pixHD method (SSIM, 0.804 ± 0.037 and FID, 43.598 ± 9.108) outperformed the two control methods (pix2pix and CRN) in enhancing MDCT images (p < 0.05). According to the subjective assessment, the pix2pixHD-derived micro-CT-like images showed no significant difference from the micro-CT images in terms of contrast and shadow (p > 0.05) but demonstrated slightly lower noise, sharpness and trabecular bone texture (p < 0.05). Compared with the trabecular microstructure parameters of micro-CT images, those of pix2pixHD-derived micro-CT-like images showed no significant differences in bone volume fraction (BV/TV) (p > 0.05) and significant correlations in trabecular thickness (Tb.Th) and trabecular spacing (Tb.Sp) (Tb.Th, R = 0.90, p < 0.05; Tb.Sp, R = 0.88, p < 0.05). The proposed method can enhance the resolution of MDCT and obtain micro-CT-like images, which may provide new diagnostic criteria and a predictive basis for osteoporosis and related fractures.

Vertebra

10.3390/tomography7040064

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Citations (6)

Research on logistics autonomous mobile robot system

Chunjie Wang Dandan Du

In recent years, Robots have become an important part of the rapid development of modern logistics system; the extent of its application has become an important measure factor to determine competition and the future development of inter-enterprise. The logistics autonomous mobile robot has a path planning, navigation, information fusion, autonomous decision-making and other human-like artificial intelligence, and it can improve the efficiency and level of intelligence of modern logistics. Due to the mobile robot working in the outdoor environment with uncertainty and complexity, its system inevitably has the uncertainty of the kinematic model, and is affected by the unknown external disturbance. In this case, it must ensure that the robot system can stabilize movement in outdoor environment and accurately reach the designated position. This is mainly related to the robot trajectory tracking problem. And the mobile robot to achieve high precision trajectory tracking control, the control method is the key. The main content of this paper is divided into two parts, one part is the introduction of the system structure of the logistics autonomous mobile robot; the other is a detailed analysis of the role of sliding mode control and neural network control in the robot system.

Mobile Robot Navigation

10.1109/icma.2016.7558574

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Citations (34)

An efficient GPU solver for 3D topology optimization of continuous fiber-reinforced composite structures

Computer Methods in Applied Mechanics and Engineering (2024)

Tianyuan Qi Junpeng Zhao Chunjie Wang

Solver

Topology optimization

10.1016/j.cma.2024.117675

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Optimal machine learning methods for radiomic prediction models: Clinical application for preoperative T₂*‐weighted images of cervical spondylotic myelopathy

JOR Spine (2021)

Mengze Zhang Hanqiang Ouyang Liang Jiang Chunjie Wang Jianfang Liu

Abstract Introduction Predicting the postoperative neurological function of cervical spondylotic myelopathy (CSM) patients is generally based on conventional magnetic resonance imaging (MRI) patterns, but this approach is not completely satisfactory. This study utilized radiomics, which produced advanced objective and quantitative indicators, and machine learning to develop, validate, test, and compare models for predicting the postoperative prognosis of CSM. Materials and methods In total, 151 CSM patients undergoing surgical treatment and preoperative MRI was retrospectively collected and divided into good/poor outcome groups based on postoperative modified Japanese Orthopedic Association (mJOA) scores. The datasets obtained from several scanners (an independent scanner) for the training (testing) cohort were used for cross‐validation (CV). Radiological models based on the intramedullary hyperintensity and compression ratio were constructed with 14 binary classifiers. Radiomic models based on 237 robust radiomic features were constructed with the same 14 binary classifiers in combination with 7 feature reduction methods, resulting in 98 models. The main outcome measures were the area under the receiver operating characteristic curve (AUROC) and accuracy. Results Forty‐one (11) radiomic models were superior to random guessing during CV (testing), with significant increased AUROC and/or accuracy ( P AUROC < .05 and/or P accuracy < .05). One radiological model performed better than random guessing during CV ( P accuracy < .05). In the testing cohort, the linear SVM preprocessor + SVM, the best radiomic model (AUROC: 0.74 ± 0.08, accuracy: 0.73 ± 0.07), overperformed the best radiological model ( P AUROC = .048). Conclusion Radiomic features can predict postoperative spinal cord function in CSM patients. The linear SVM preprocessor + SVM has great application potential in building radiomic models.

10.1002/jsp2.1178

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Citations (8)

High-order involute modified noncircular bevel gears

Journal of Advanced Mechanical Design Systems and Manufacturing (2014)

Jiqiang Xia Kan Shi Chunjie Wang

Noncircular bevel gears (NBGs) is a kind of spatial transmission mechanism which can be used to transmit the motion and power between two intersecting axes with a variable transmission ratio and according to a suitable motion program. Given that the pitch curve and tooth profile curve of NBGs are spherical curve rather than plane curve, the research methods on NBGs is complicated than bevel gears as well as plane noncircular gears. In this paper, the pitch curve equations of NBGs are obtained for any order and in any configuration during their pure rolling based on the spherical polar coordinate system. The relationship of least teeth number avoiding undercutting and the pitch curve curvature of NBGs is analyzed. Being directed against high-order involute NBGs drive, a kind of varying-coefficient-profile-shift-modification method has been presented. The equations of the modified addendum and dedendum curves are implemented in MATLAB. The algorithm for generating tooth profile of NBGs by the hypothetical involute modified shaper cutter under UG platform is proposed and some significant examples are included. The 3D models and prototype of a pair of conjugate high-order involute modified NBGs are demonstrated to verify the correctness of this modification method.

Bevel gear

Bevel

10.1299/jamdsm.2014jamdsm0019

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Citations (11)

[Effects of hepatocyte growth factor gene transfer in combination with echocardiographic destruction of microbubbles in a rat model of experimental myocardial infarction.].

PubMed (2008)

Cong Yang Ping Fang Chunjie Wang Yue-ping Tan Dan Hu

To evaluate whether ultrasonic microbubble destruction (US/MB) could enhance the therapeutic effects of hepatocyte growth factor (HGF) gene transfer for acute myocardial infarction (MI).MI was induced by left anterior descending artery ligation in male SD rats. Two to 4 hours thereafter, MI rats were randomly treated with tail vein infusing pc-DNA3.1-HGF plasmid mixed with microbubbles (US/MB-HGF group, n = 18); tail vein infusing pc-DNA3.1-HGF plasmid mixed with saline (US-HGF group, n = 18); tail vein infusing empty plasmid mixed with microbubbles (US/MB-P group, n = 18). All rats were exposed to ultrasound treatment thereafter till contrast imaging disappeared in cardiac region. Rats were sacrificed at 24 hours, 7 days or 14 days, respectively (n = 6 each) and myocardial protein expression of bcl-2 and HGF as well as microvascular density (MVD) were determined.The myocardial protein expressions of bcl-2 and HGF in US/MB-HGF group were significantly higher than those in US-HGF and US/MB-P groups at 7 days post MI (all P < 0.01) and MVD was significantly higher in US/MB-HGF group (367.6 +/- 17.6) than that in US-HGF (268.9 +/- 0.8) and US/MB-P (186.8 +/- 11.8) groups (all P < 0.05) at 14 days post MI.Ultrasound-mediated microbubble destruction could enhance systemic HGF administration induced myocardial angiogenesis and reduce systemic HGF administration induced myocardial apoptosis in rats with acute MI.

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A preliminary study using spinal MRI-based radiomics to predict high-risk cytogenetic abnormalities in multiple myeloma

La radiologia medica (2021)

Jianfang Liu Chunjie Wang Wei Guo Piaoe Zeng Yan Liu

Nomogram

10.1007/s11547-021-01388-y

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Citations (24)

Design Framework for Motion Generation of Planar Four-Bar Linkage Considering Clearance Joints and Dynamics Performance

Machines (2022)

Xueao Liu Jianzhong Ding Chunjie Wang

In this paper, we present a novel design framework to connect linkage synthesis with dynamics performance of the linkage. The aim of the design framework is to improve the dynamics performance of the mechanism through linkage design, instead of improving manufacturing accuracy or changing driving strategy. Specifically, the design framework is to complete motion generation of four-bar linkage, considering clearance joints and dynamics performance. The constraint model of motion generation and the dynamics model of four-bar linkage are established, respectively. The coordinates of four joints of four-bar linkage are divided into two parts, one of parts is the parameters to improve the dynamics performance of the linkage and is selected as the optimization variables. The other parts of joint coordinates is to satisfy the kinematics requirements and is obtained by solving constraint equations of motion generation. Through optimization calculation, we can obtain the optimal configuration of the four-bar linkage that achieves specified task positions with high motion accuracy and low wear extent of clearance joint. Finally, a numerical example is proposed to demonstrate the novel design framework.

Linkage (software)

Four-bar linkage

Dynamics

Bar (unit)

10.3390/machines10020136

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Citations (6)