33 research outputs found

    An effective approach for the dual-resource flexible job shop scheduling problem considering loading and unloading

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    Many manufacturing systems need more than one type of resource to co-work with. Commonly studied flexible job shop scheduling problems merely consider the main resource such as machines and ignore the impact of other types of resource. As a result, scheduling solutions may not put into practice. This paper therefore studies the dual resource constrained flexible job shop scheduling problem when loading and unloading time (DRFJSP-LU) of the fixtures is considered. It formulates a multi-objective mathematical model to jointly minimize the makespan and the total setup time. Considering the influence of resource requirement similarity among different operations, we propose a similarity-based scheduling algorithm for setup-time reduction (SSA4STR) and then an improved non-dominated sorting genetic algorithm II (NSGA-II) to optimize the DRFJSP-LU. Experimental results show that the SSA4STR can effectively reduce the loading and unloading time of fixtures while ensuring a level of makespan. The experiments also verify that the scheduling solution with multiple resources has a greater guiding effect on production than the scheduling result with a single resource

    The complete mitochondrial genome of the stink bug Eocanthecona furcellata (Hemiptera: Pentatomidae)

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    The predatory stink bug Eocanthecona furcellata belongs to the subfamily Asopinae of Pentatomidae. In the current study, the complete mitochondrial genome of E. furcellata is determined. This mitogenome is 16,085 bp in size and comprises of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a control region. Gene order is identical to that of the putative ancestral arrangement of insects. Nucleotide composition is biased toward A and T, which together made up 75.5% of the entire genome. All tRNAs have the clover-leaf structure except for the tRNASer(AGN) and the length of them ranges from 61 to 73 bp. The monophyly of Pentatomidae is highly supported by the phylogenetic tree and E. furcellata is very close to other carnivorous species of the remaining Pentatomidae species

    Fixed-Time Synchronization of Neural Networks Based on Quantized Intermittent Control for Image Protection

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    This paper considers the fixed-time synchronization (FIXTS) of neural networks (NNs) by using quantized intermittent control (QIC). Based on QIC, a fixed-time controller is designed to ensure that the NNs achieve synchronization in finite time. With this controller, the settling time can be estimated regardless of initial conditions. After ensuring that the system has stabilized through this strategy, it is suitable for image protection given the behavior of the system. Meanwhile, the encryption effect of the image depends on the encryption algorithm, and the quality of the decrypted image depends on the synchronization error of NNs. The numerical results show that the designed controller is effective and validate the practical application of FIXTS of NNs in image protection

    Cognitive Changes following Bilateral Deep Brain Stimulation of Subthalamic Nucleus in Parkinson’s Disease: A Meta-Analysis

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    Background. Nowadays, it has been largely acknowledged that deep brain stimulation of subthalamic nucleus (STN DBS) can alleviate motor symptoms of Parkinson’s disease, but its effects on cognitive function remain unclear, which are not given enough attention by many clinical doctors and researchers. To date, 3 existing meta-analyses focusing on this issue included self-control studies and have not drawn consistent conclusions. The present study is the first to compare effect sizes of primary studies that include control groups, hoping to reveal the net cognitive outcomes after STN DBS and the clinical significance. Methods. A structured literature search was conducted using strict criteria. Only studies with control group could be included. Data on age, duration of disease, levodopa equivalent dosage (LED), and multiple cognitive scales were collected and pooled. Results. Of 172 articles identified, 10 studies (including 3 randomized controlled trials and 7 nonrandomized controlled studies) were eligible for inclusion. The results suggest that STN DBS results in decreased global cognition, memory, verbal fluency, and executive function compared with control group. No significant difference is found in other cognitive domains. Conclusions. STN DBS seems relatively safe with respect to cognitive function, and further studies should focus on the exact mechanisms of possible verbal deterioration after surgery in the future

    State of Health Estimation Based on the Long Short-Term Memory Network Using Incremental Capacity and Transfer Learning

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    Battery state of health (SOH) estimating is essential for the safety and preservation of electric vehicles. The degradation mechanism of batteries under different aging conditions has attracted considerable attention in SOH prediction. In this article, the discharge voltage curve early in the cycle is considered to be strongly characteristic during cell aging. Therefore, the battery aging state can be quantitatively characterized by an incremental capacity analysis (ICA) of the voltage distribution. Due to the interference of vibration noise of the test platform, the discrete wavelet transform (DWT) methods are accustomed to soften the premier incremental capacity curves in different hierarchical decompositions. By analyzing the battery aging mechanism, the peak of the curve and its corresponding voltage are used in the characterization of capacity decay by grey relation analysis (GRA) and to optimize the input of the deep learning model, and finally, the double-layer long short-term memory network (LSTM) model is used to train the data. The results demonstrate that the proposed model can predict the SOH of a single battery cycle using only small batch data and the relative error is less than 2%. Further, by freezing the LSTM layer for transfer learning, it can be used for battery health estimation in different loading modes. The results of training and verification show that this method has high accuracy and reliability in SOH estimation

    A Review of Lithium-Ion Battery State of Health Estimation and Prediction Methods

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    Lithium-ion power batteries have been widely used in transportation due to their advantages of long life, high specific power, and energy. However, the safety problems caused by the inaccurate estimation and prediction of battery health state have attracted wide attention in academic circles. In this paper, the degradation mechanism and main definitions of state of health (SOH) were described by summarizing domestic and foreign literatures. The estimation and prediction methods of lithium-ion power battery SOH were discussed from three aspects: model-based methods, data-driven methods, and fusion technology methods. This review summarizes the advantages and disadvantages of the current mainstream SOH estimation and prediction methods. This paper believes that more innovative feature parameter extraction methods, multi-algorithm coupling, combined with cloud platform and other technologies will be the development trend of SOH estimation and prediction in the future, which provides a reference for health state estimation and prediction of lithium-ion power battery

    Early Sexual Initiation Is Associated with Suicide Attempts among Chinese Young People

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    This study aimed to investigate the association between early sexual initiation and suicide attempts (SAs) among Chinese young people. Our analysis included 9131 college students who had sexual experience from a national sample of 31 provincial administrative regions. Self-reported age at first intercourse was categorized as ≤15, 15–18, and ≥18 years, and the experience of SAs was recorded and analyzed. Compared with females whose sexual debut age was ≥18 years, those ≤15 years (defined as early sexual initiation) had higher odds of SAs in both the forced debut group (odds ratio (OR) 17.04, 95% confidence interval (CI) 4.87–59.66) and the voluntary debut group (OR 37.63, 95% CI 14.96–94.66). Early sexual initiators who lived in rural areas were more inclined to have SAs (female: OR 65.76, 95% CI 19.80–218.42; male: OR 15.39, 95% CI 1.64–144.19). Early sexual initiators who never had parent–child communication about sex were more likely to report having SAs (female: OR 37.81, 95% CI 12.28–116.46). Sexual debut during adolescence, particularly early sexual initiation, was a crucial risk factor for SAs among both sexes. Comprehensive sexuality education and smooth parental communication about sex will provide a supportive environment for young people and hence reduce the potential risks of SAs

    Impairments in Brain Perfusion, Metabolites, Functional Connectivity, and Cognition in Severe Asymptomatic Carotid Stenosis Patients: An Integrated MRI Study

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    Carotid artery stenosis without transient ischemic attack (TIA) or stroke is considered as “asymptomatic.” However, recent studies have demonstrated that these asymptomatic carotid artery stenosis (aCAS) patients had cognitive impairment in tests of executive function, psychomotor speed, and memory, indicating that “asymptomatic” carotid stenosis may not be truly asymptomatic. In this study, when 19 aCAS patients compared with 24 healthy controls, aCAS patients showed significantly poorer performance on global cognition, memory, and executive function. By utilizing an integrated MRI including pulsed arterial spin labeling (pASL) MRI, Proton MR Spectroscopy (MRS), and resting-state functional MRI (R-fMRI), we also found that aCAS patients suffered decreased cerebral blood flow (CBF) mainly in the Left Frontal Gyrus and had decreased NAA/Cr ratio in the left hippocampus and decreased connectivity to the posterior cingulate cortex (PCC) in the anterior part of default mode network (DMN)
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