34 results on '"Huang, Xiaofei"'
Search Results
2. A Hybrid Denoising Method for Electromagnetic Acoustic Detection
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Huang, Xiaofei, Xie, Yuedong, Liu, Fulu, Li, Jiyao, Jiang, Wenshuo, Huang, Pu, Sun, Hu, Liang, Haibo, He, Sha, Hao, Wei, and Xu, Lijun
- Abstract
The electromagnetic acoustic transducer (EMAT) consisting of racetrack coils presents directionality, and hence, waves propagating in sidelobe directions experience significant energy attenuation, resulting vulnerability to noise interference. To address the challenge of weak signal denoising, a novel denoising method is proposed based on a combination of the Butterworth bandpass filtering, an improved continuous wavelet transform (CWT) incorporating high-order statistical (HOS) and block threshold (BT), and Wiener filtering. The proposed method is verified by means of simulations and experiments. In the simulations, a periodic permanent magnet EMAT (PPM-EMAT) model was established to illustrate the directivity of PPM-EMAT and generate mimic shear horizontal (SH) waves to demonstrate the effectiveness of the proposed denoising method. In the experiments, the actual receiving signals from different transmitting angles were extracted based on the fabricated PPM-EMAT. Experimental results showed that the proposed method can significantly improve signal-to-noise ratios (SNRs) of the signals received at both the main-lobe direction and sidelobe direction while maintaining the signal characteristics compared with other denoising methods, especially presenting SNRs increase from 3.67 to 13.74 dB within a 60° beam angle of the radiation pattern. The proposed denoising method will provide a foundation for high-resolution imaging and weak signal denoising below 20 dB based on PPM-EMAT.
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- 2024
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3. Insight to the Catalytic Activity of Atomically Precise Ag4Ni2 Nanoclusters on Silicon Carbide for Nitroarene Reduction.
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Xiao, Yutong, Huang, Xiaofei, Li, Hou, Han, Qing-Wen, Zhang, Yu, Tian, Fan, and Xu, Man
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- 2024
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4. Insight to the Catalytic Activity of Atomically Precise Ag4Ni2Nanoclusters on Silicon Carbide for Nitroarene Reduction
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Xiao, Yutong, Huang, Xiaofei, Li, Hou, Han, Qing-Wen, Zhang, Yu, Tian, Fan, and Xu, Man
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Atomically precise Ag4Ni2nanoclusters with 2,4-dimethylbenzenethiol as the ligands were synthesized and characterized as a cocatalyst of SiC for the selective hydrogenation of nitroarenes to arylamine in the presence of NaBH4. The obtained Ag4Ni2/SiC samples exhibited extraordinary catalytic activity, and a self-accelerated catalytic process was observed with the reduction of nitrophenol to aminophenol as the model reaction. Experimental comparison between the Ag4Ni2/SiC samples before and after the catalysis showed that the transformation of Ag4Ni2clusters to polydisperse Ag particles as well as amorphous NiOxon the surface of SiC in the catalysis was the key to their high activity. AIMD calculations revealed that the transformation of Ag4Ni2was driven by the presence of multiple hydrides on the cluster, which induced the detachment of the thiol ligand of the nanoclusters.
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- 2024
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5. A Dual-Attention Learning Network With Word and Sentence Embedding for Medical Visual Question Answering
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Huang, Xiaofei and Gong, Hongfang
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Research in medical visual question answering (MVQA) can contribute to the development of computer-aided diagnosis. MVQA is a task that aims to predict accurate and convincing answers based on given medical images and associated natural language questions. This task requires extracting medical knowledge-rich feature content and making fine-grained understandings of them. Therefore, constructing an effective feature extraction and understanding scheme are keys to modeling. Existing MVQA question extraction schemes mainly focus on word information, ignoring medical information in the text, such as medical concepts and domain-specific terms. Meanwhile, some visual and textual feature understanding schemes cannot effectively capture the correlation between regions and keywords for reasonable visual reasoning. In this study, a dual-attention learning network with word and sentence embedding (DALNet-WSE) is proposed. We design a module, transformer with sentence embedding (TSE), to extract a double embedding representation of questions containing keywords and medical information. A dual-attention learning (DAL) module consisting of self-attention and guided attention is proposed to model intensive intramodal and intermodal interactions. With multiple DAL modules (DALs), learning visual and textual co-attention can increase the granularity of understanding and improve visual reasoning. Experimental results on the ImageCLEF 2019 VQA-MED (VQA-MED 2019) and VQA-RAD datasets demonstrate that our proposed method outperforms previous state-of-the-art methods. According to the ablation studies and Grad-CAM maps, DALNet-WSE can extract rich textual information and has strong visual reasoning ability.
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- 2024
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6. Analysis and Suppression for Critical Optical Nonorthogonal Noise in SERF Comagnetometers
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Xu, Zitong, Wei, Kai, Liu, Chang, Heng, Xing, Huang, Xiaofei, Gong, Dinghui, Wang, Fan, Zhai, Yueyang, and Quan, Wei
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Ultrasensitive atomic comagnetometers have proven to be valuable tools for precise measurement and search for new physics. Besides, comagnetometers have potential for inertial navigation and quantum information. Despite their great potential, sensitivity improvement has been limited by different types of noise. To address this issue, the sources and magnitudes of noises are comprehensively analyzed and a suppression method is proposed for the most critical noise source, optical nonorthogonality. The optical nonorthogonality leads to critical transverse pumping effect, thus transverse light shift, and transverse effective magnetic noise. A direct correlation between the optical nonorthogonality and the electronic spin transverse relaxation rate is found, and a method for suppression of the optical nonorthogonality is proposed accordingly. Finally, the optical nonorthogonal noise is suppressed by 3.1 dB. Besides, an increase of 5.2 dB in the scale factor is achieved. With the combined effect of noise suppression and scale factor enhancement, the resulting inertial rotation sensitivity of
$2.4 \times 10^{-8}$ $^{1/2}$ - Published
- 2024
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7. HST-MRF: Heterogeneous Swin Transformer With Multi-Receptive Field for Medical Image Segmentation
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Huang, Xiaofei, Gong, Hongfang, and Zhang, Jin
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The Transformer has been successfully used in medical image segmentation due to its excellent long-range modeling capabilities. However, patch segmentation is necessary when building a Transformer class model. This process ignores the tissue structure features within patch, resulting in the loss of shallow representation information. In this study, we propose a Heterogeneous Swin Transformer with Multi-Receptive Field (HST-MRF) model that fuses patch information from different receptive fields to solve the problem of loss of feature information caused by patch segmentation. The heterogeneous Swin Transformer (HST) is the core module, which achieves the interaction of multi-receptive field patch information through heterogeneous attention and passes it to the next stage for progressive learning, thus complementing the patch structure information. We also designed a two-stage fusion module, multimodal bilinear pooling (MBP), to assist HST in further fusing multi-receptive field information and combining low-level and high-level semantic information for accurate localization of lesion regions. In addition, we developed adaptive patch embedding (APE) and soft channel attention (SCA) modules to retain more valuable information when acquiring patch embedding and filtering channel features, respectively, thereby improving model segmentation quality. We evaluated HST-MRF on multiple datasets for polyp, skin lesion and breast ultrasound segmentation tasks. Experimental results show that our proposed method outperforms state-of-the-art models and can achieve superior performance. Furthermore, we verified the effectiveness of each module and the benefits of multi-receptive field segmentation in reducing the loss of structural information through ablation experiments and qualitative analysis.
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- 2024
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8. A Defects Detection Method of Buried Liquid-Filled Pipes Based on T(0,1) Guided Waves
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Liu, Fulu, Li, Zhiying, Huang, Xiaofei, Ma, Linhui, Li, Jiyao, Pu, Hang, Long, Jun, Xu, Lijun, and Xie, Yuedong
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In this article, we propose a method using
$T$ $T$ $T$ - Published
- 2024
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9. Catalytic Hydrogenation of Nitroarenes over Ag33 Nanoclusters: The Ligand Effect.
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Yuan, Jianglu, Huang, Xiaofei, Zhang, Weihua, Zhou, Mengting, Li, Guangfang, Tian, Fan, and Chen, Rong
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- 2023
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10. Weak Interaction between Nickel Thiolate and g‑C3N4 Improving Electron–Hole Separation for Photocatalysis.
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Tian, Fan, Huang, Xiaofei, Li, Wangxuan, An, Yixuan, Li, Guangfang, and Chen, Rong
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- 2023
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11. Ultrasensitive Optical Rotation Detection With Closed-Loop Suppression of Spin Polarization Error
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Heng, Xing, Wei, Kai, Zhao, Tian, Xu, Zitong, Cao, Qian, Huang, Xiaofei, Zhai, Yueyang, Ye, Mao, and Quan, Wei
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Optical rotation detection system (ORDS) utilizing quantum nondemolition (QND) measurement methods is widely applied in the field of quantum metrology and quantum information. However, the sensitivity of ORDS is limited by the uncertainty from optical-couple noise during the measurement of the atomic spin ensemble. In this study, we specifically analyze the mechanism of optical-couple noise caused by the fluctuations of probe light’s polarization in the modulated ORDS with a new model established to describe atomic spin precession in this particular condition. It is discovered that transverse electron-spin polarization errors are generated by the residual probe photon spin polarization in the ORDS, which results in extra coupling magnetic noise. In order to suppress this noise, a novel in situ method is proposed that the resultant electron-spin errors are reduced by a specifically designed closed-loop system. The results are verified through the ORDS in a co-magnetometer. After zeroing the extra probe photon spin polarization, an angular sensitivity better than
$1 \times 10 ^{\mathrm {-8}}$ $^{\mathrm {1/2}}$ $^{\mathrm {1/2}}$ $25.7 \mu $ - Published
- 2023
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12. Simultaneously-Collected Multimodal Lying Pose Dataset: Enabling In-Bed Human Pose Monitoring
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Liu, Shuangjun, Huang, Xiaofei, Fu, Nihang, Li, Cheng, Su, Zhongnan, and Ostadabbas, Sarah
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Computer vision field has achieved great success in interpreting semantic meanings from images, yet its algorithms can be brittle for tasks with adverse vision conditions and the ones suffering from data/label pair limitation. Among these tasks is in-bed human pose monitoring with significant value in many healthcare applications. In-bed pose monitoring in natural settings involves pose estimation in complete darkness or full occlusion. The lack of publicly available in-bed pose datasets hinders the applicability of many successful human pose estimation algorithms for this task. In this paper, we introduce our Simultaneously-collected multimodal Lying Pose (SLP) dataset, which includes in-bed pose images from 109 participants captured using multiple imaging modalities including RGB, long wave infrared (LWIR), depth, and pressure map. We also present a physical hyper parameter tuning strategy for ground truth pose label generation under adverse vision conditions. The SLP design is compatible with the mainstream human pose datasets; therefore, the state-of-the-art 2D pose estimation models can be trained effectively with the SLP data with promising performance as high as 95% at PCKh@0.5 on a single modality. The pose estimation performance of these models can be further improved by including additional modalities through the proposed collaborative scheme.
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- 2023
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13. Balanced Light-Assisted Hybrid Spin Exchange Optical Pumping in SERF Comagnetometers
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Xu, Zitong, Wei, Kai, Huang, Xiaofei, Gong, Dinghui, Wang, Weiyi, Liu, Chang, Heng, Xing, Wang, Fan, Zhai, Yueyang, and Quan, Wei
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Ultrasensitive spin exchange relaxation-free (SERF) comagnetometers have been widely applied in various new physics experiments and show great potential for inertial navigation. However, the spatially nonuniform spin polarization of alkali metal (AM) and noble gas (NG) atoms results in an effective magnetic field gradient on the order of 100 nT/cm which is much larger than that is produced by the coils and remanence on the magnitude of 1 nT/cm, thereby reducing the suppression ability of the magnetic noise and limiting the scale factor and noise floor of the comagnetometers. In this study, we establish a model of the effective magnetic field gradient caused by uneven spin polarization and analyze the influencing factors. Our results indicate that optimizing the density ratio of hybrid AM atoms can suppress the effective magnetic field gradient. Nevertheless, the available pump light power imposes a limitation on the density ratio. To further address this issue, we propose a balanced light-assisted hybrid spin exchange optical pumping (HSEOP) method. Our experimental results confirm the effectiveness of the mentioned approach, with 67% suppression of the nuclear transverse relaxation rate and a nearly threefold increase in the scale factor. Furthermore, the optimal density ratio in experimental applications can be reduced from 200 to below 80, thereby overcoming the limitation of laser power in SERF comagnetometers and providing the possibility for wider applications. Finally, the suppression factor of magnetic noise is enhanced by 89% by optimizing the density ratio and the balanced light-assisted HSEOP method. This research sheds light on the fundamental physics experiments and potential for inertial navigation.
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- 2023
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14. Conductivity and Side-Length Measurement of Square Metallic Plates With Finite Dimension Based on Eddy Current Method
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Huang, Pu, Huang, Xiaofei, Pu, Hang, Xu, Lijun, and Xie, Yuedong
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The classic Dodd and Deeds model has been applied to estimate the electromagnetic properties of samples in eddy current testing (ECT). In fact, the model is only suitable for the condition that sample is much larger than the radius of coil (generally speaking, three–five times larger). However, the dimension of the samples cannot meet the condition in some practical applications. This article first investigated the modified analytical solution for square metallic plates with finite dimension based on Dodd and Deeds, of which the lower limit of integral changes from 0 to a value related with the side length of square sample. Furthermore, the modified truncated region eigenfunction expansion (TREE) analytical is also established for finite square plate by truncating the range of eigenvalues. Based on the modified analytical solution, the conductivity and side length measurement of square metallic plates with finite dimension has been presented. The experiments have been carried out to verify the conductivity and side length measurement method, and the results show the average errors are only 2.3% and 0.9%, respectively.
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- 2023
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15. Non-contrast enhanced silent MR angiography to evaluate hemodynamics and morphology of unruptured intracranial aneurysms: a comparative computational fluid dynamics study
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Lu, Yuzhao, Leng, Xiaochang, Zou, Rong, Chen, Qi, Li, Wenqiang, Zhou, Xiaobing, Tan, Song, Huang, Xiaofei, Ding, Cong, Gong, Feixiang, Xiang, Jianping, and Wang, Yang
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BackgroundSilent MR angiography (silent MRA) is a new generation of non-contrast enhanced angiography with outstanding advantages in visualizing cerebrovascular lesions and the follow-up after endovascular treatment for intracranial aneurysms (IAs). This study aims to investigate the reliability of silent MRA-based three-dimensional (3D) geometric description and hemodynamic calculation of IAs.Methods19 patients with 23 unruptured IAs, who underwent both silent MRA and 3D rotational angiography (3DRA), were included in this study. Computational fluid dynamics simulations were performed on all patient-specific 3D reconstruction images to compare the morphology and hemodynamics of the two different imaging models for IAs.ResultsSilent MRA models had smaller maximum and perpendicular height (mm), aneurysmal surface area (mm2), and aneurysmal volume (mm3) than 3DRA (p<0.05); the differences of the above parameters between the two models were 9.0±6.2%, 7.7±7.4%, 15.9±13.0%, and 21.4±17.5%, respectively. However, correlation analysis of morphological parameters in various dimensions and model comparison showed good overall consistency in geometrical characteristics between the two models. Moderate coherence was observed between models in time-averaged wall shear stress of aneurysm and parent vessel (TAWSS, PAWSS), aneurysm velocity (AV), parent vessel velocity, and oscillatory shear index (OSI). However, strong correlations were observed among normalized aneurysm wall shear stress (NWSS), low shear area (LSA), inflow concentration index (ICI), and normalized aneurysm velocity (NAV).ConclusionBoth morphological and hemodynamic assessments of IAs for silent MRA are comparable to 3DRA. Additionally, normalized indicators such as NWSS, LSA, ICI, and NAV were better than TAWSS, AV, and OSI in silent MRA-related hemodynamic evaluation.
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- 2023
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16. Decibel level of coughing as a predictor of extubation outcome in mechanically ventilated intensive care patients: A prospective, observational study.
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Li, Huan, Zhou, Tiantian, Ni, Haibin, Wang, Tingting, Wei, Yanli, Huang, Xiaofei, and Lyu, Jian
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This study aims to evaluate the feasibility and clinical utility of measuring cough decibel level as predictive markers for extubation outcomes in mechanically ventilated patients. A prospective observational study. Three interdisciplinary medical-surgical intensive care units across China. The primary outcomes assessed were extubation results in patients. Secondary measures included the cough decibel level, semiquantitative cough intensity scores, and white card test results recorded prior to extubation. A total of 71 patients were included, 55 patients were in the extubation success group and 16 in the failure group. The mean age was 78(71,83) years, mainly male (73.2 %). Despite the baseline characteristics being mostly consistent across both groups, significant differences were noted in duration of mechanical ventilation, and intensive care units and hospital stay. Remarkably, the cough decibel was substantially lower in the extubation failure group compared to the other group (78.69 ± 8.23 vs 92.28 ± 7.01 dB). The Receiver Operating Characteristic curve analysis revealed that a cough decibel below 85.77 dB is the optimal threshold for predicting extubation failure, exhibiting an 80 % sensitivity and 91.67 % specificity. The study corroborates that the cough decibel level serves as a quantifiable metric in patients undergoing mechanical ventilation. It posits that the likelihood of extubation failure escalates when the cough decibel falls below 85.77 dB. Quantification of coughing capacity in decibels may be a good predictor of extubation outcome, thus offering assistance to healthcare professionals in evaluating the readiness of patients for extubation. [ABSTRACT FROM AUTHOR]
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- 2024
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17. Landscape design and planning methods for plant protection based on deep learning and remote sensing techniques.
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Yang, Dongxing and Huang, Xiaofei
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DEEP learning ,LANDSCAPE design ,PLANT protection ,REMOTE sensing ,DISTANCE education ,LANDSCAPE protection ,REGIONAL development - Abstract
Landscape design and planning can play a role in beautifying the human living environment while improving the ecological protection of plants. However, it is difficult because it involves ornamental, ecological, social and other factors. Remote sensing data can be acquired and analyzed from vegetation distribution, ecological environment, land use and other information to support rational planning and design of plant protection landscape. Deep learning technology provides a powerful tool for the comprehensive use of remote sensing data to support plant protection landscape design. In this paper, a multiple dense network (MP-DenseNet) model is constructed based on Densenet to accomplish the task of classifying the vegetation cover of remotely sensed data, which provides data support for the design and planning of plant protection landscapes. The algorithm proposed in this paper is competitive in comparison with several models. Using the MP-DenseNet model, this paper categorizes the vegetation cover of the study area and proposes an overall planning scheme that balances plant protection and regional sustainable development. • Constructing RSI vegetation classification model MP-DenseNet based on DenseNet. • The MP-DenseNet model is trained with RSI and verified for superior performance. • Development planning scenarios for the study area using the MP-DenseNet model. [ABSTRACT FROM AUTHOR]
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- 2024
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18. The osteoclastic activity in apical distal region of molar mesial roots affects orthodontic tooth movement and root resorption in rats
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Zheng, Wenhao, Lu, Xiaofeng, Chen, Guangjin, Shen, Yufeng, Huang, Xiaofei, Peng, Jinfeng, Wang, Jiajia, Yin, Ying, Song, Wencheng, Xie, Mengru, Yu, Shaoling, and Chen, Lili
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The utilization of optimal orthodontic force is crucial to prevent undesirable side effects and ensure efficient tooth movement during orthodontic treatment. However, the sensitivity of existing detection techniques is not sufficient, and the criteria for evaluating optimal force have not been yet established. Here, by employing 3D finite element analysis methodology, we found that the apical distal region (A-D region) of mesial roots is particularly sensitive to orthodontic force in rats. Tartrate-resistant acidic phosphatase (TRAP)-positive osteoclasts began accumulating in the A-D region under the force of 40 grams (g), leading to alveolar bone resorption and tooth movement. When the force reached 80 g, TRAP-positive osteoclasts started appearing on the root surface in the A-D region. Additionally, micro-computed tomography revealed a significant root resorption at 80 g. Notably, the A-D region was identified as a major contributor to whole root resorption. It was determined that 40 g is the minimum effective force for tooth movement with minimal side effects according to the analysis of tooth movement, inclination, and hyalinization. These findings suggest that the A-D region with its changes on the root surface is an important consideration and sensitive indicator when evaluating orthodontic forces for a rat model. Collectively, our investigations into this region would aid in offering valuable implications for preventing and minimizing root resorption during patients’ orthodontic treatment.
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- 2024
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19. Stock price series forecasting using multi-scale modeling with boruta feature selection and adaptive denoising.
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Li, Jing, Liu, Yukun, Gong, Hongfang, and Huang, Xiaofei
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STOCK price forecasting ,MULTISCALE modeling ,FEATURE selection ,OPTIMIZATION algorithms ,BUSINESS forecasting - Abstract
In recent times, predicting stock prices has garnered attention from both regulators and academic circles. However, the intricate nature of financial time-series data, with its nonlinearities, discontinuities, and sensitivity to noise, complicates the understanding and forecasting of financial movements. In our approach, we initially deploy an adaptive empirical modal decomposition on the primary data to enhance model precision. Subsequently, we sift the technical indicator data through the Boruta method, enhancing selected functionalities via an adaptive noise reduction technique. We then employ support vector regression (SVR) integrated with brain storm optimization algorithm (BSO) for effective data handling and forecasting target variables. Our results suggest that the composite model outlined in this paper outperforms the other eight comparison models in terms of reducing errors and improving regression scores. Additionally, when juxtaposed against these four models, the outcomes reinforce the efficiency of our proposed multiscale strategy and denoising technique in refining prediction accuracy. • Adaptive selection of technical indicators as input features using the Boruta feature selection algorithm. • Adaptive denoising of input features based on the proposed MIC-ICEEMDAN denoising algorithm. • The reconstruction uses the enhanced BSO-SVR model to predict the prediction results of each IMF and residual term Res. [ABSTRACT FROM AUTHOR]
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- 2024
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20. Comparison of membrane fouling and cleaning in one-pass reverse osmosis and two-pass nanofiltration approaches to seawater desalination
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Tanuwidjaja, Dian, Jin, Xue, Huang, Xiaofei, Marambio-Jones, Catalina, Jawor, Anna, Zhang, Minglu, Jiang, Sunny, Cheng, Robert, and Hoek, Eric M.V.
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A recent innovation in seawater desalination is the use of multi-stage and multi-pass combinations of nanofiltration (NF) and reverse osmosis (RO) membranes. One example of this approach is the “Long Beach method,” in which seawater passes through two different types of NF membranes to produce potable water. After several years of pilot studies comparing the performance of two-pass NF and single-pass RO systems, a number of membrane elements were sacrificed for autopsy analyses. The selected membranes represent different stages of operation including (1) new, (2) fouled, and (3) cleaned membranes. Used NF and RO spiral wound elements were removed from the first and last positions of the demonstration plant. Although operating data suggested no outward signs of membrane fouling – inorganic, organic, and bacterial accumulation were identified on all membranes. First pass RO and NF membranes contained similar amounts of deposited solids, while significantly fewer solids were found on second pass NF membranes. Viable, culturable marine bacteria were observed on all fouled and cleaned membranes, indicating that bacterial colonization of seawater NF/RO membranes was not (a) detected by plant performance monitoring devices, (b) prevented by microfiltration and chlorination, or (c) removed by chemical cleaning. Chemical cleaning recovered the measurable performance of both first pass RO and second pass NF membranes, but was relatively ineffective at removing deposited solids from first-pass NF membranes. Therefore, chemical-cleaning methods may need to be tailored and optimized more specifically for NF membranes used in seawater desalination.
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- 2020
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21. Understanding the Roles of Thiophenol-Ligated Ag-Based Nanoclusters on TiO2during the Catalytic Hydrogenation of Nitroarenes
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Huang, Xiaofei, Xiao, Yutong, Li, Yulin, Han, Qingwen, Fang, Wanggang, He, Liqing, Tian, Fan, and Chen, Rong
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Elucidating the correlations between the core structure of atomically precise nanoclusters and their catalytic activities is fundamentalfor exploring highly efficient nanocatalysts. Herein, a series of Ag-based nanoclusters protected by 2,4-dimethylphenylthiophenol (specifically Ag4Pd2(SPhMe2)8and Ag24M(SPhMe2)18where M = Ag, Pd, and Pt) were synthesized and deposited on TiO2supports as heterogeneous catalysts for the selective hydrogenation of nitroarenes with NaBH4as the reductant. It was found that Ag4Pd2(SPhMe2)8could spontaneously lose its ligands during catalysis, leading to the formation of polydispersed AgPd nanoparticles. This transformation endows the system with extraordinary activity for driving the hydrogenation of nitroarenes. However, the Ag24M (M = Ag, Pd, and Pt) systems, maintain their core structures during catalysis. They follow the generally reported ligand-mediated hydride-involved process, with catalytic activities depending on the central atom (Pt > Pd > Ag), which affects the hydride transferred from the nanoclusters to the reactant to regulate the catalysis.
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- 2024
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22. Numerical simulation and experiment on the law of urban natural gas leakage and diffusion for different building layouts.
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Liu, Aihua, Huang, Jian, Li, Zhiwen, Chen, Jieyun, Huang, Xiaofei, Chen, Ke, and Xu, Wen bin
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COMPUTATIONAL fluid dynamics ,NATURAL gas ,NATURAL gas pipelines ,COMPUTATIONAL physics ,COMPARATIVE studies - Abstract
To provide a more reliable theoretical basis for emergency-management decisions following accidental natural gas leaks, a numerical simulation and an experiment were conducted in this study to investigate the effects of complex construction environments on natural gas leakage and diffusion laws. The design of a building was divided into an enclosed layout, a patch layout, and a street canyon layout, from the perspective of their impact on environmental winds. Natural gas leakage and diffusion in three layouts were simulated using a three-dimensional computational fluid dynamics (CFD) model, in which both the distribution of natural gas concentration and dangerous areas were determined through comparative analysis. The results of a small-sized experiment showed that the blocking function of an enclosed layout for environmental wind was the highest, its vortex effect was the strongest, and its range of high gas concentration was the widest among the layouts. A cavity among the buildings was the site of major gas accumulation, making it the most crucial area for the emergency management of accidental natural gas leaks. The proposed CFD model was demonstrated be able to be used to simulate and predict the diffusion of natural gas in cases of accidental leakage. And the results of this study can guide building layout planning and gas pipeline construction to prevent accidents. [ABSTRACT FROM AUTHOR]
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- 2018
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23. Dam-zoning modulus reconstruction using adjoint method
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Gu, Hao, Wu, Zhongru, Huang, Xiaofei, Song, Jintao, and Sun, L.Z.
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Mechanical properties of ageing dams and rock foundations can differ significantly from those design values used during construction. It is necessary to conduct the inverse analysis of mechanical parameters of dam and rock foundation. However, it is inconsistent with the actual situation by utilising the conventional inversion method for structural analysis, as the conventional method can only inverse the integrated elastic modulus. Therefore, a new inversion method is proposed in this paper, which utilises adjustment coefficient to inverse initial elastic modulus, and introduces the adjoint method combined with DFP quasi Newton method in order to inverse zoning elastic modulus of dam and rock foundation. The adjoint method calculates the gradients in a much more efficient way, as it can avoid the repeated computation of large stiffness matrix. Therefore, the time consumption is reduced greatly and the computational efficiency increases significantly. Combined with project case, the feasibility and validity of the proposed method are verified.
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- 2018
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24. Catalytic Hydrogenation of Nitroarenes over Ag33Nanoclusters: The Ligand Effect
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Yuan, Jianglu, Huang, Xiaofei, Zhang, Weihua, Zhou, Mengting, Li, Guangfang, Tian, Fan, and Chen, Rong
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Using ligand-protected metallic nanoclusters with atomic precision as catalysts and elucidating its ligand effect in the catalysis are the prerequisites to deepen the structure–catalysis relationship of nanoclusters at the molecular level. Herein, a series of Ag33nanoclusters protected with different thiolate ligands (2-phenylethanethiol, 4-chlorobenzyl mercaptan, and 4-methoxybenzyl mercaptan as precursors) were synthesized and used as heterogeneous catalysts for the conversion of nitroarenes to arylamine with NaBH4as reductant. The obtained nanoclusters exhibited ligand-dependent catalytic activity, with benzyl thiolate ligands distinctly superior to the phenethyl thiolate ligands. DFT calculations revealed that the ligand regulated catalytic activity of the nanoclusters was ascribed to the H−π and π–π interactions between the ligands and the substrates, owing to the presence of phenyl rings in these structures. This work highlighted the importance of the ligands on the metallic nanoclusters in catalysis and provides a strategy to regulate the catalytic activity by utilizing weak interactions between the catalysts and the substrates.
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- 2023
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25. Low intensity near-infrared light promotes bone regeneration via circadian clock protein cryptochrome 1
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Peng, Jinfeng, Zhao, Jiajia, Tang, Qingming, Wang, Jinyu, Song, Wencheng, Lu, Xiaofeng, Huang, Xiaofei, Chen, Guangjin, Zheng, Wenhao, Zhang, Luoying, Han, Yunyun, Yan, Chunze, Wan, Qian, and Chen, Lili
- Abstract
Bone regeneration remains a great clinical challenge. Low intensity near-infrared (NIR) light showed strong potential to promote tissue regeneration, offering a promising strategy for bone defect regeneration. However, the effect and underlying mechanism of NIR on bone regeneration remain unclear. We demonstrated that bone regeneration in the rat skull defect model was significantly accelerated with low-intensity NIR stimulation. In vitro studies showed that NIR stimulation could promote the osteoblast differentiation in bone mesenchymal stem cells (BMSCs) and MC3T3-E1 cells, which was associated with increased ubiquitination of the core circadian clock protein Cryptochrome 1 (CRY1) in the nucleus. We found that the reduction of CRY1 induced by NIR light activated the bone morphogenetic protein (BMP) signaling pathways, promoting SMAD1/5/9 phosphorylation and increasing the expression levels of Runx2and Osterix. NIR light treatment may act through sodium voltage-gated channel Scn4a, which may be a potential responder of NIR light to accelerate bone regeneration. Together, these findings suggest that low-intensity NIR light may promote in situ bone regeneration in a CRY1-dependent manner, providing a novel, efficient and non-invasive strategy to promote bone regeneration for clinical bone defects.
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- 2022
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26. Global Optimality Conditions and Near-Perfect Optimization in Coding.
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Wang, Lusheng and Huang, Xiaofei
- Abstract
Finding ways of recognizing global optimum is the very fundamental, unsolved problem in existing optimization theories. We can not establish a true theory of optimization without it. Also, it is very hard to construct effective algorithms for finding global optimum. This paper presented a new optimization principle, called cooperative optimization, for solving this extremely important problem in optimization theory. A number of global optimality conditions are provided in a general form. The application of cooperative optimization in coding yields near-perfect results in finding global optima, significantly better than the most powerful optimization algorithm ever found so far. [ABSTRACT FROM AUTHOR]
- Published
- 2005
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27. A General Extension of Constraint Propagation for Constraint Optimization.
- Author
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Wallace, Mark and Huang, Xiaofei
- Abstract
In this paper, we propose a general extension of constraint propagation for constraint optimization based on cooperative computation. It is similar both in principle and operations to constraint propagation. In principle, it eliminates variable values by checking the feasibility that they can be in any global optimum. In operations, it is based on parallel, local iterative computations. The proposed algorithm returns both a solution and a global lower bound at each iteration. As an approximation algorithm for optimization, it significantly outperform classical optimization methods, such as simulated annealing and local search with multi-restarts in practice. [ABSTRACT FROM AUTHOR]
- Published
- 2004
28. Ammonium reduction kinetics in drinking water by newly isolated Acinetobactersp. HITLi 7 at low temperatures
- Author
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Qin, Wen, Li, Weiguang, Zhang, Duoying, Huang, Xiaofei, and Song, Yang
- Abstract
AbstractThe Acinetobactersp. HITLi 7 was isolated from the Songhua River and shown to be capable of heterotrophic nitrification ability at 2°C. To predict the ammonium reduction performance in drinking water at low temperature, the kinetics of strain HITLi 7 were investigated using Monod kinetic models. The results of calculations showed that the substrate half saturation constant Kswas 9.9 mg/L of total ammonium, and the maximum specific rate μmaxwas 7.9 × 10−4 h−1at 8°C, C/N 2, pH 6.0 while shaking at 100 r/min. The effects of temperature (2, 5 and 8°C), C/N (2, 4, and 10), and pH (6.0, 7.0, and 7.5) on kinetic parameters were also evaluated. Ksand μmaxincreased consistently with an increase in temperature and decreased as C/N ratio increased. The specific affinity a0(a0 = μmax/Ks) for ammonium was the highest for a C/N of 10. This value was 2.1-fold higher than the affinity observed for a C/N of 2. The results demonstrated that the affinity of HITLi 7 for ammonium was higher when a sufficient carbon source was present. The maximum ammonium reduction rate was 0.18 mg -N/L/h at a C/N of 10. These results suggest that HITLi 7 may be used for ammonium removal in drinking water at low temperatures.
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- 2016
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29. Ammonium reduction kinetics in drinking water by newly isolated Acinetobactersp. HITLi 7 at low temperatures
- Author
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Qin, Wen, Li, Weiguang, Zhang, Duoying, Huang, Xiaofei, and Song, Yang
- Abstract
The Acinetobactersp. HITLi 7 was isolated from the Songhua River and shown to be capable of heterotrophic nitrification ability at 2°C. To predict the ammonium reduction performance in drinking water at low temperature, the kinetics of strain HITLi 7 were investigated using Monod kinetic models. The results of calculations showed that the substrate half saturation constant Kswas 9.9 mg/L of total ammonium, and the maximum specific rate μmaxwas 7.9 × 10−4 h−1at 8°C, C/N 2, pH 6.0 while shaking at 100 r/min. The effects of temperature (2, 5 and 8°C), C/N (2, 4, and 10), and pH (6.0, 7.0, and 7.5) on kinetic parameters were also evaluated. Ksand μmaxincreased consistently with an increase in temperature and decreased as C/N ratio increased. The specific affinity a0(a0= μmax/Ks) for ammonium was the highest for a C/N of 10. This value was 2.1-fold higher than the affinity observed for a C/N of 2. The results demonstrated that the affinity of HITLi 7 for ammonium was higher when a sufficient carbon source was present. The maximum ammonium reduction rate was 0.18 mg NH4+-N/L/h at a C/N of 10. These results suggest that HITLi 7 may be used for ammonium removal in drinking water at low temperatures.
- Published
- 2016
- Full Text
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30. Fe-Mn-sepiolite as an effective heterogeneous Fenton-like catalyst for the decolorization of reactive brilliant blue
- Author
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Su, Chengyuan, Li, Weiguang, Liu, Xingzhe, Huang, Xiaofei, and Yu, Xiaodan
- Abstract
A study of the decolorization of reactive brilliant blue in an aqueous solution using Fe-Mn-sepiolite as a heterogeneous Fenton-like catalyst has been performed. The Fourier transform infrared (FTIR) spectra of the catalyst showed bending vibrations of the Fe-O. The Xray diffraction (XRD) patterns of the catalyst showed characteristic diffraction peaks of α-Fe2O3, γ-Fe2O3and MnO. A four factor central composite design (CCD) coupled with response surface methodology (RSM) was applied to evaluate and optimize the important variables (catalyst addition, hydrogen peroxide dosage, initial pH value and initial dye concentration). When the reaction conditions were catalyst dosage = 0.4 g, [H2O2]= 0.3 mL, pH = 2.5, [reactive brilliant blue]o= 50mg·L−1, and volume of solution = 500 mL at room temperature, the decolorization efficiency of reactive brilliant blue was 91.98% within 60 min. Moreover, the Fe-Mn-sepiolite catalyst had good stability for the degradation of reactive brilliant blue even after six cycles. Leaching of iron ions (<0.4 mg·L−1) was observed. The decoloring process was reactive brilliant blue specific via a redox reaction. The benzene ring and naphthalene ring were first oxidized to open ring; these were then oxidized to the alcohol and carboxylic acid. The reactive brilliant blue was decomposed mainly by the attack of ·OH radicals including surface-bound ·OH radicals generated on the catalyst surface.
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- 2016
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31. Purification and characterization of a low-temperature ammonia monooxygenase from heterotrophic nitrifier Acinetobactersp. Y16
- Author
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Zhang, Shumei, Li, Weiguang, Zhang, Duoying, Huang, Xiaofei, Qin, Wen, and Gu, Jun
- Abstract
Low-temperature ammonia monooxygenase (AMO) was purified from a heterotrophic nitrifier Acinetobactersp. Y16 by anion-exchange and gel-filtration chromatography. The purified enzyme was a membrane-bound monomer with a molecular mass of approximately 31 kDa. It could catalyze the oxidation of ammonium without stabilizing agents in vitroat low temperature. Addition of CuCl2could stimulate AMO activity in vitro. The enzyme was stable in the temperature range of 4–15°C with less than 9% change in its activity. The optimal activity temperature was 15°C. Above 20°C, the enzyme completely lost its activity. The enzyme activity was stable when stored at 4°C for five days, at 10°C for two days, and at 15°C for one day. This study purified a highly pure AMO from a heterotrophic nitrifier Acinetobactersp. for the first time.
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- 2015
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32. Demethyleneberberine induces cell cycle arrest and cellular senescence of NSCLC cells via c-Myc/HIF-1α pathway.
- Author
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Liu, Jingfeng, Huang, Xiaofei, Liu, Dandan, Ji, Kaiyuan, Tao, Cheng, Zhang, Ren, and Chen, Jian
- Abstract
Background: Demethyleneberberine (DMB) is a natural active component of medicinal plant Cortex phellodendri chinensis with favorable bioactivity. However, the role of DMB in suppressing non-small cell lung cancer (NSCLC) remains unknown.Purpose: In this study, we aimed to examine the effect and underlying mechanism of DMB in suppressing NSCLC.Methods: CCK8 assay and colony formation assay were utilized to assess the efficiency of DMB on the viability and colony formation capacity of NSCLC cells. Flow cytometry and β-Galactosidase Staining Kit were utilized to determine the efficiency of DMB on the cell cycle and cellular senescence of NSCLC cells. RT-qPCR and Western blot were used to detect the effect of DMB on cell cycle and cellular senescence related gene and protein expression of NSCLC cells. In vivo tumor model was established to evaluate the anti NSCLC effect of DMB. In addition, RNA-seq analysis was performed to detect the differential gene expression after DMB treatments.Results: In this study, we revealed that DMB exhibits efficient inhibitory effect on NSCLC cell proliferation and tumor xenografts growth in vivo. We also demonstrated that DMB could inhibit cell migration by suppressing epithelial-mesenchymal transition (EMT) and trigger cell cycle arrest by down-regulating the expression of cell cycle related genes in NSCLC cells. In addition, DMB treatment efficiently induces cellular senescence of NSCLC cells. From the RNA-seq analysis, we found that DMB accelerates senescence through suppressing HIF-1α expression, which was further elucidated by overexpressing HIF-1α in NSCLC to reduce the inhibitory effect of DMB. Furthermore, we also revealed that DMB decreases the expression of c-Myc, an up-stream protein of HIF-1α.Conclusions: Taken together, we first report that DMB inhibits NSCLC progress through inducing cell cycle arrest and triggering cellular senescence by downregulating c-Myc/HIF-1α pathway. [ABSTRACT FROM AUTHOR]- Published
- 2021
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33. A polynomial-time algorithm for solving NP-hard problems in practice
- Author
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Huang, Xiaofei
- Abstract
Constraint-based optimization, which is NP-hard, describes a large class of problems in many fields, especially in formulating early perception tasks. For example, Shape from shading of a polyhedron [12, 11] in computer vision can be formulated under such a paradigm. Some of the traditional problem-solving methods, like the exhaustive search, guarantee finding the global solution, but are too expensive in practice. Local Search, Simulated Annealing, Tabu Search, and the evolutionary algorithms have no general conditions to stop searching when the global optimum is what we are looking for. In this paper, we will present a polynomial-time algorithm [5 ]for solving the practical problems. The algorithm has many interesting computational properties not possessed by the classic ones. It is guaranteed to converge linearly, insensitive to the perturbations to its initial conditions and intermediate solutions. The closeness of the solutions to the optimal ones in cost is always provided by the algorithm so that we can stop search when the gap is closed or is small enough. It has a number of sufficient conditions for identifying optimal solutions, and a number of necessary conditions for reducing the search spaces. With 1,000 test problems randomly generated by computer, the Local Search algorithm with multiple restarts has a successful rate of only 0.2% after 25 iterations, and the Simulated Annealing algorithm [7, 2 ] with a linear cooling scheme has a successful rate of 1.5% after 250,000 steps. In contrast, the new algorithm achieved a successful rate of over 98% after only 7.27 iterations on average.
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- 2003
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34. Sintilimab induced diabetic ketoacidosis in a patient with small cell lung cancer
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Huang, Xiaofei, Yang, Mei, Wang, Liu, Li, Libo, Zhong, Xiaowei, and Saranathan., Maya
- Published
- 2021
- Full Text
- View/download PDF
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