Authors: Wang, Peng | Cheng, Jun | Feng, Wei
Article Type: Research Article
Abstract: Path planning for human beings is based on scene understanding and semantic map as well as geometry features. The point cloud map can help robots to perform path planning. However, it is quite different from the natural way of human beings. In this paper, we propose to construct a novel framework for topological semantic map. Specifically, we construct a 2D semantic map by projecting 3D scene semantic information recognized by convolutional neural network onto a 2D plane. 3D reconstruction of the environment is achieved by RGB-D SLAM 3D space mapping algorithm. The intersections in the 2D map are recognized offline, …and the semantic annotation of the intersection in the topological map is utilized to build up a complete object-based semantic map. Experimental results demonstrate the feasibility of the proposed approach. Show more
Keywords: Topological semantic map, 3D information, convolution neural network, schematic diagram
DOI: 10.3233/JIFS-169656
Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 3, pp. 3011-3020, 2018
Authors: Zhang, Kun | Zhao, Haojie | Feng, Wei | Wu, Zhaoyun | Liu, Baoguo
Article Type: Research Article
Abstract: Diamagnetic levitation is a physical phenomenon that uses the diamagnetism of diamagnetic materials to stably levitate itself in an external strong magnetic field, which has great potential in the areas of sensors, actuators, and biomedicine. In this paper, a typical diamagnetic levitation system composed of a NdFeB permanent magnet array and pyrolytic graphite sheet is built. The levitation mechanism of the diamagnetic levitation system is analyzed theoretically, the main factors affecting the static levitation of the pyrolytic graphite sheet are determined, and the influence of structural parameters on the levitation height of the pyrolytic graphite sheet is studied. Furthermore, the …dynamic and numerical simulation models of the diamagnetic levitation system are established, and the dynamic response characteristics of the pyrolytic graphite sheet are analyzed under different vibration excitation. This study provides a reference for developing applications based on the diamagnetic levitation system. Show more
Keywords: Diamagnetic levitation, static levitation, dynamic response, vibration, collision
DOI: 10.3233/JAE-220066
Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. 2, pp. 133-147, 2023
Authors: Shi, Zhongyong | Wu, Yujie | Wang, Meijuan | Cao, Jing | Feng, Wei | Cheng, Yan | Li, Chunbo | Shen, Yuan
Article Type: Research Article
Abstract: Thinning of retinal nerve fiber layer (RNFL) may reflect neurodegeneration of the central nervous system, which has been reported as part of the neuropathogenesis of Alzheimer's disease (AD). Specifically, AD patients have thinner RNFL as compared to age-matched normal controls. However, whether reduction of RNFL over time can predict those at higher risk to develop cognitive deterioration remains unknown. We therefore set out a prospective clinical investigation to determine both the reduction of RNFL thickness and the deterioration of cognitive function over a period of 25 months in 78 participants (mean age 72.31 ± 3.98 years, 52% men). The participants …were categorized as stable participants whose cognitive status remained unchanged (n = 60) and converted participants whose cognitive status deteriorated, which was diagnosed by DSM-VI (for AD) and Petersen's definition (for mild cognitive impairment) (n = 18). Here we show for the first time that the converted participants had greater reduction of RNFL thickness than the stable participants. Specifically, the reduction in the thickness of the inferior quadrant RNFL in the converted participants was greater than that in stable participants [−11.0 ± 12.8 (mean ± standard deviation) μm versus 0.4 ± 15.7 μm, p = 0.009]. These data showed that greater reduction in the inferior quadrant of RNFL thickness might indicate a higher risk for the old adults to develop cognitive deterioration. These findings have established a system to embark on a larger scale study to further test whether changes in RNFL thickness can serve as a biomarker of AD. Show more
Keywords: Alzheimer's disease, cognitive function, mild cognitive impairment, retinal nerve fiber layer thickness
DOI: 10.3233/JAD-131898
Citation: Journal of Alzheimer's Disease, vol. 40, no. 2, pp. 277-283, 2014
Authors: Feng, Wei | Zhang, Kun | Liu, Zongyao | Liu, Baoguo | Zhang, Huijuan | Mei, Junwei | Wu, Luji
Article Type: Research Article
Abstract: The unbalanced magnetic pull (UMP) is one of the main vibration sources of the motorized spindle. A calculation model of UMP in a synchronous motorized spindle considering the magneto-thermal coupling is proposed in this paper. The finite element analysis models of the electromagnetic field and the temperature field of a motorized spindle are first established. Then a two-way coupling analysis method considering the effect of temperature variations on electromagnetic material properties of the motor is proposed. An experiment is conducted to verify the efficiency of this method. The thermal deformations of the spindle are calculated and used to analyze the …air-gap variations between rotor and stator of the built-in motor. The 3D finite element electromagnetic model is adopted to calculate the UMP in the motorized spindle. The analysis results show that the eccentricity caused by thermal deformation can generate large UMP in the motorized spindle. Show more
Keywords: Unbalanced magnetic pull, synchronous motorized spindle, magneto-thermal coupling, air gap length, thermal deformation
DOI: 10.3233/JAE-220034
Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 70, no. 3, pp. 303-321, 2022
Authors: Shi, Xian-Quan | Dong, Yunyun | Tan, Xiaoqu | Yang, Peipei | Wang, Chunmei | Feng, Wei | Lin, Yuxuan | Qian, Linxue
Article Type: Research Article
Abstract: OBJECTIVE: This study was performed to investigate the accuracy of conventional ultrasound (US), contrast-enhanced US (CEUS), and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the size of breast cancer. METHODS: In total, 49 breast cancer lesions of 48 patients were included in this study. The inclusion criteria were the performance of total mastectomy or breast-conserving surgery for treatment of breast cancer in our hospital from January 2017 to December 2020 with complete pathological results, as well as the performance of conventional US, CEUS, and DCE-MRI examinations with complete results. The exclusion criteria were non-mass breast cancer shown on conventional …US or DCE-MRI, including that found on CEUS with no boundary with surrounding tissues and no confirmed tumor scope; a tumor too large to be completely displayed in the US section, thus affecting the measurement results; the presence of two nodules in the same breast that were too close to each other to be distinguished by any of the three imaging methods; and treatment with preoperative chemotherapy. Preoperative conventional US, CEUS, and DCE-MRI examinations were performed. The postoperative pathological results were taken as the gold standard. The lesion size was represented by its maximum diameter. The accuracy, overestimation, and underestimation rates of conventional US, CEUS, and DCE-MRI were compared. RESULTS: The maximum lesion diameter on US, CEUS, DCE-MRI and pathology were 1.62±0.63 cm (range, 0.6–3.5 cm), 2.05±0.75 cm (range, 1.0–4.0 cm), 1.99±0.74 cm (range, 0.7–4.2 cm) and 1.92±0.83 cm (range, 0.5–4.0 cm), respectively. The lesion size on US was significantly smaller than that of postoperative pathological tissue (P < 0.05). However, there was no significant difference between the CEUS or DCE-MRI results and the pathological results. The underestimation rate of conventional US (55.1%, 27/49) was significantly higher than that of CEUS (20.4%, 10/49) and DCE-MRI (24.5%, 12/49) (P < 0.001 and P = 0.002, respectively). There was no significant difference in the accuracy of CEUS (36.7%, 18/49) and DCE-MRI (34.7%, 17/49) compared with conventional US (26.5%, 13/49); however, the accuracy of both groups tended to be higher than that of conventional US. The overestimation rate of CEUS (42.9%, 21/49) and DCE-MRI (40.8%, 20/49) was significantly higher than that of conventional US (18.4%, 9/49) (P = 0.001 and P = 0.015, respectively). CONCLUSIONS: CEUS and DCE-MRI show similar performance when evaluating the size of breast cancer. However, CEUS is more convenient, has a shorter operation time, and has fewer restrictions on its use. Notably, conventional US is more prone to underestimate the size of lesions, whereas CEUS and DCE-MRI are more prone to overestimate the size. Show more
Keywords: Ultrasound, contrast-enhanced ultrasound, dynamic contrast-enhanced magnetic resonance imaging, breast, breast cancer
DOI: 10.3233/CH-221456
Citation: Clinical Hemorheology and Microcirculation, vol. 82, no. 2, pp. 157-168, 2022
Authors: Feng, Wei | Yokoyama, Jennifer S. | Yu, Shunying | Chen, You | Cheng, Yan | Bonham, Luke W. | Wang, Dongxiang | Shen, Yuan | Wu, Wenyuan | Li, Chunbo
Article Type: Research Article
Abstract: Background: Cognitive training may contribute to the ability to maintain cognitive function in healthy elderly adults. Whether genotype modifies training effects remains unknown. Objective: Assess influence of APOE on cognitive function over time in community-dwelling elderly adults participating in multi-domain cognitive training. Methods: Healthy individuals ≥70 years of age were screened from one urban community in Shanghai. 145 healthy Chinese older adults met inclusion criteria and were assigned to intervention (n = 88) or control (n = 57) groups. Multi-domain cognitive training involved 24 sessions of different content taking place over 12 weeks. Neuropsychological testing was administered at baseline, immediately after training, …six months and twelve months post-intervention; composite measures of cognitive function were identified via factor analysis. Results: Three factors explained the majority of variance in function (verbal memory, processing speed, executive function). The intervention attenuated 12-month declines in processing speed, regardless of APOE genotype (p = 0.047). Executive function declined in APOE ɛ 4 carriers over 12 months, regardless of intervention (p = 0.056). There was a significant interaction after 12 months where intervention ɛ 4 carriers had better processing speed than ɛ 4 controls (p = 0.003). Intervention ɛ 2 carriers had better executive function immediately after training (p = 0.02) and had better verbal memory 6-months post-intervention (p = 0.04). These effects remained significant after false-discovery rate correction. Conclusion: Multi-domain cognitive training reduces declines in processing speed over time. APOE ɛ 4 is associated with reductions in executive function over time, and training may attenuate ɛ 4-associated declines in processing speed. APOE ɛ 2 carriers may also benefit from training, particularly on measures of executive function and verbal memory. Show more
Keywords: Apolipoprotein E, cognitive training, elderly, neuropsychology
DOI: 10.3233/JAD-150039
Citation: Journal of Alzheimer's Disease, vol. 47, no. 4, pp. 1035-1046, 2015
