Genetic Algorithms

遗传算法
  • 文章类型: Journal Article
    在现代制造业中,优化算法已成为提高加工技术效率和质量的关键工具。随着计算技术的进步和人工智能的发展,这些算法在加工过程的参数优化中起着越来越重要的作用。目前,响应面法的发展,遗传算法,Taguchi方法,粒子群优化算法相对成熟,在工艺参数优化中的应用相当广泛。它们越来越多地用作表面粗糙度的优化目标,地下损伤,切削力,和机械性能,加工和特殊加工。本文对优化算法在实际工程生产领域的应用和发展趋势进行了系统的回顾。它深入研究了分类,定义,以及工程制造过程中工艺参数优化算法的研究现状,国内和国际。此外,它提供了这些优化算法在实际场景中的具体应用的详细探索。优化算法的演变旨在增强未来制造业的竞争力,促进制造技术向更高的效率发展,可持续性和定制。
    In modern manufacturing, optimization algorithms have become a key tool for improving the efficiency and quality of machining technology. As computing technology advances and artificial intelligence evolves, these algorithms are assuming an increasingly vital role in the parameter optimization of machining processes. Currently, the development of the response surface method, genetic algorithm, Taguchi method, and particle swarm optimization algorithm is relatively mature, and their applications in process parameter optimization are quite extensive. They are increasingly used as optimization objectives for surface roughness, subsurface damage, cutting forces, and mechanical properties, both for machining and special machining. This article provides a systematic review of the application and developmental trends of optimization algorithms within the realm of practical engineering production. It delves into the classification, definition, and current state of research concerning process parameter optimization algorithms in engineering manufacturing processes, both domestically and internationally. Furthermore, it offers a detailed exploration of the specific applications of these optimization algorithms in real-world scenarios. The evolution of optimization algorithms is geared towards bolstering the competitiveness of the future manufacturing industry and fostering the advancement of manufacturing technology towards greater efficiency, sustainability, and customization.
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  • 文章类型: Journal Article
    气体传感器的一个挑战是湿度干扰,由于动态湿度条件可能导致对分析物的响应信号发生不可预测的波动,增加定量检测误差。这里,我们介绍一个概念:从水池中选择湿度传感器来补偿每个气体传感器的湿度信号。与极端抑制湿度响应的传统方法相比,传感器池允许更准确的气体定量在更广泛的应用场景提供定制,高维湿度响应数据作为外在补偿。作为一个概念证明,通过三个步骤实现了比色气体定量中湿度干扰的缓解。首先,跨越十维变量空间,一个算法驱动的高通量实验机器人发现了多个局部最佳区域,在这些区域中,比色湿度传感公式对灵敏度具有很高的评价,可逆性,响应时间,和在室温(25°C)下10-90%相对湿度(RH)的颜色变化程度。第二,从局部最优区域,选择具有不同变量的91种传感配方来构建母体比色湿度传感器阵列作为湿度信号补偿的传感器池。第三,准最佳传感器子阵列被确定为定制的湿度信号补偿解决方案,适用于大约全动态湿度范围(10-90%RH)的不同气体传感场景,使用巧妙的组合优化策略,并获得了两个准确的定量检测:一个平均绝对百分比误差(MAPE)从4.4%降低到0.75%,另一个从5.48%降低到1.37%。此外,父传感器阵列出色的湿度选择性已针对10种气体进行了验证。这项工作证明了机器人辅助构建可定制的父比色传感器阵列以减轻气体定量中的湿度干扰的可行性和优越性。
    One challenge for gas sensors is humidity interference, as dynamic humidity conditions can cause unpredictable fluctuations in the response signal to analytes, increasing quantitative detection errors. Here, we introduce a concept: Select humidity sensors from a pool to compensate for the humidity signal for each gas sensor. In contrast to traditional methods that extremely suppress the humidity response, the sensor pool allows for more accurate gas quantification across a broader range of application scenarios by supplying customized, high-dimensional humidity response data as extrinsic compensation. As a proof-of-concept, mitigation of humidity interference in colorimetric gas quantification was achieved in three steps. First, across a ten-dimensional variable space, an algorithm-driven high-throughput experimental robot discovered multiple local optimum regions where colorimetric humidity sensing formulations exhibited high evaluations on sensitivity, reversibility, response time, and color change extent for 10-90% relative humidity (RH) in room temperature (25 °C). Second, from the local optimum regions, 91 sensing formulations with diverse variables were selected to construct a parent colorimetric humidity sensor array as the sensor pool for humidity signal compensation. Third, the quasi-optimal sensor subarrays were identified as customized humidity signal compensation solutions for different gas sensing scenarios across an approximately full dynamic range of humidity (10-90% RH) using an ingenious combination optimization strategy, and two accurate quantitative detections were attained: one with a mean absolute percentage error (MAPE) reduction from 4.4 to 0.75% and the other from 5.48 to 1.37%. Moreover, the parent sensor array\'s excellent humidity selectivity was validated against 10 gases. This work demonstrates the feasibility and superiority of robot-assisted construction of a customizable parent colorimetric sensor array to mitigate humidity interference in gas quantification.
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  • 文章类型: Journal Article
    为解决干燥塔内大米水分在线检测中存在的稳定性差、监测精度低的问题,设计了干燥塔出口大米水分在线检测装置。采用了三极板电容器的结构,并利用COMSOL软件对三极板电容器的静电场进行了仿真。对厚度进行了三因素五层次的中心复合设计,间距,板的面积为影响因素,电容比灵敏度为测试指标。该装置由动态采集装置和检测系统组成。发现动态采样装置采用十形叶板结构实现了水稻的动态连续采样和静态间歇测量。设计了以STM32F407ZGT6为主控芯片的巡检系统硬件电路,实现了主从机之间的稳定通信。此外,利用MATLAB软件建立了基于遗传算法的优化BP神经网络预测模型。还进行了室内静态和动态验证试验。结果表明,最佳板结构参数组合包括板厚度为1mm,板间距为100毫米,18,000.069mm2的相对面积,同时满足装置的机械设计和实际应用需求。BP神经网络的结构为2-90-1,遗传算法中个体代码长度为361,对预测模型进行765次训练,得到的最小MSE值为1.9683×10-5,低于未优化的BP神经网络的MSE为7.1215×10-4。静态试验下装置的平均相对误差为1.44%,动态试验下装置的平均相对误差为2.103%,满足了器件设计的精度要求。
    To solve the problems of poor stability and low monitoring precision in the online detection of rice moisture in the drying tower, we designed an online detection device for rice moisture at the outlet of the drying tower. The structure of a tri-plate capacitor was adopted, and the electrostatic field of the tri-plate capacitor was simulated using COMSOL software. A central composite design of three factors and five levels was carried out with the thickness, spacing, and area of the plates as the influencing factors and the capacitance-specific sensitivity as the test index. This device was composed of a dynamic acquisition device and a detection system. The dynamic sampling device was found to achieve dynamic continuous sampling and static intermittent measurements of rice using a ten-shaped leaf plate structure. The hardware circuit of the inspection system with STM32F407ZGT6 as the main control chip was designed to realize stable communication between the master and slave computers. Additionally, an optimized BP neural network prediction model based on the genetic algorithm was established using the MATLAB software. Indoor static and dynamic verification tests were also carried out. The results showed that the optimal plate structure parameter combination includes a plate thickness of 1 mm, plate spacing of 100 mm, and relative area of 18,000.069 mm2 while satisfying the mechanical design and practical application needs of the device. The structure of the BP neural network was 2-90-1, the length of individual code in the genetic algorithm was 361, and the prediction model was trained 765 times to obtain a minimum MSE value of 1.9683 × 10-5, which was lower than that of the unoptimized BP neural network with an MSE of 7.1215 × 10-4. The mean relative error of the device was 1.44% under the static test and 2.103% under the dynamic test, which met the accuracy requirements for the design of the device.
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  • 文章类型: Journal Article
    同步加速器光源的断层成像方法不断发展,在高空间和时间分辨率下推动多模态表征能力。为了实现这一目标,小探头尺寸和多维扫描方案更常用于光束线,导致实验设置过程中的复杂性和挑战不断增加。为了避免在对准X射线探头上花费大量的人力和波束时间,用于数据采集的样品和检测器,人们最关注的是在数据处理阶段重新调整系统。然而,后处理不能纠正一切,并且没有时间效率。在这里,我们使用软件方法结合了遗传算法和人类智能的优点,在数据采集过程中和之前介绍了旋转轴和样本的自动对准方案。我们的方法在短时间内显示出两种任务的出色子像素对齐效率,因此,在未来扫描层析成像实验的数据采集系统中具有巨大的应用潜力。
    Tomography imaging methods at synchrotron light sources keep evolving, pushing multi-modal characterization capabilities at high spatial and temporal resolutions. To achieve this goal, small probe size and multi-dimensional scanning schemes are utilized more often in the beamlines, leading to rising complexities and challenges in the experimental setup process. To avoid spending a significant amount of human effort and beam time on aligning the X-ray probe, sample and detector for data acquisition, most attention has been drawn to realigning the systems at the data processing stages. However, post-processing cannot correct everything, and is not time efficient. Here we present automatic alignment schemes of the rotational axis and sample pre- and during the data acquisition process using a software approach which combines the advantages of genetic algorithms and human intelligence. Our approach shows excellent sub-pixel alignment efficiency for both tasks in a short time, and therefore holds great potential for application in the data acquisition systems of future scanning tomography experiments.
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  • 文章类型: Journal Article
    背景:急性肾损伤(AKI)是脓毒症的常见并发症。然而,脓毒症诱导的AKI的轨迹及其转录谱没有得到很好的表征.
    方法:纳入2020年11月至2021年12月参加中国脓毒症多组学进展(CMAISE)中心的脓毒症患者,在第1天测量外周血单核细胞中的基因表达。在第1天和第3天通过SOFA评分(SOFARenal)的肾脏分量测量肾功能轨迹。第1天的转录谱在这些肾功能轨迹之间进行比较,并开发了支持向量机(SVM)来区分瞬态AKI和持久性AKI。
    结果:研究期间共纳入172例脓毒症患者。肾功能轨迹分为四种类型:非AKI(SOFARenal=0,第1天和第3天,n=50),持续性AKI(第1天和第3天的SOFrecial>0,n=62),短暂性AKI(第1天SOFrecial>0,第3天SOFrecial=0,n=50)和AKI恶化(第1天SOFrecial=0,第3天SOFrecial>0,n=10)。持续性AKI组表现出严重的器官功能障碍和对器官支持的长期需求。恶化的AKI组在第1天显示出最少的器官功能障碍,但与非AKI和短暂性AKI组相比,血清乳酸更高,血管加压药的使用时间更长。在持续性和短暂性AKI组之间有2091个上调和1,902个下调基因(调整后的p<0.05),随着质膜复合物的富集,受体复合物,和T细胞受体复合物。利用遗传算法建立了一个43基因的SVM模型,与基于保留子集的临床变量的模型相比,显示出预测持续性AKI的性能明显更高(AUC:0.948[0.912,0.984]vs.0.739[0.648,0.830];德隆检验p<0.01)。
    结论:我们的研究根据肾损伤轨迹确定了脓毒症诱导的AKI的四种亚型。表征了这些亚型的宿主反应畸变的景观。建立了基于基因标记的SVM模型来预测肾功能轨迹,并显示出比基于临床变量的模型更好的性能。未来的研究有必要验证基因模型在区分持久性和暂时性AKI方面的作用。
    Acute kidney injury (AKI) is a common complication in sepsis. However, the trajectories of sepsis-induced AKI and their transcriptional profiles are not well characterized.
    Sepsis patients admitted to centres participating in Chinese Multi-omics Advances In Sepsis (CMAISE) from November 2020 to December 2021 were enrolled, and gene expression in peripheral blood mononuclear cells was measured on Day 1. The renal function trajectory was measured by the renal component of the SOFA score (SOFArenal) on Days 1 and 3. Transcriptional profiles on Day 1 were compared between these renal function trajectories, and a support vector machine (SVM) was developed to distinguish transient from persistent AKI.
    A total of 172 sepsis patients were enrolled during the study period. The renal function trajectory was classified into four types: non-AKI (SOFArenal = 0 on Days 1 and 3, n = 50), persistent AKI (SOFArenal > 0 on Days 1 and 3, n = 62), transient AKI (SOFArenal > 0 on Day 1 and SOFArenal = 0 on Day 3, n = 50) and worsening AKI (SOFArenal = 0 on Days 1 and SOFArenal > 0 on Day 3, n = 10). The persistent AKI group showed severe organ dysfunction and prolonged requirements for organ support. The worsening AKI group showed the least organ dysfunction on day 1 but had higher serum lactate and prolonged use of vasopressors than the non-AKI and transient AKI groups. There were 2091 upregulated and 1,902 downregulated genes (adjusted p < 0.05) between the persistent and transient AKI groups, with enrichment in the plasma membrane complex, receptor complex, and T-cell receptor complex. A 43-gene SVM model was developed using the genetic algorithm, which showed significantly greater performance predicting persistent AKI than the model based on clinical variables in a holdout subset (AUC: 0.948 [0.912, 0.984] vs. 0.739 [0.648, 0.830]; p < 0.01 for Delong\'s test).
    Our study identified four subtypes of sepsis-induced AKI based on kidney injury trajectories. The landscape of host response aberrations across these subtypes was characterized. An SVM model based on a gene signature was developed to predict renal function trajectories, and showed better performance than the clinical variable-based model. Future studies are warranted to validate the gene model in distinguishing persistent from transient AKI.
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  • 文章类型: Journal Article
    农业害虫的危害对食用农产品的质量和安全产生了显著的影响,基于物联网(IoT)的农业害虫监测和识别产生了大量的数据需要传输。为了实现害虫监测传感器数据的高效实时传输,本文选取235个农业害虫监测点的地理坐标,采用遗传算法,粒子群优化(PSO),和模拟退火(SA)来优化传感器的数据传输路径。利用MATLAB软件对这三种智能算法进行了仿真。结果表明,基于粒子群算法的优化路径可以使数据传输时间最短,最小时间为4.868012s。本研究可为提高农业有害生物监测数据的传输效率提供参考,为制定实时有效的虫害防治策略提供保障,并进一步减少虫害对农产品安全的威胁。
    The harm of agricultural pests presents a remarkable effect on the quality and safety of edible farm products and the monitoring and identification of agricultural pests based on the Internet of Things (IoT) produce a large amount of data to be transmitted. To achieve efficient and real-time transmission of the sensors\' data for pest monitoring, this paper selects 235 geographic coordinates of agricultural pest monitoring points and uses genetic algorithm (GA), particle swarm optimization (PSO), and simulated annealing (SA) to optimize the data transmission paths of sensors. The three intelligent algorithms are simulated by MATLAB software. The results show that the optimized path based on PSO can make the shortest time used for transmitting data, and its corresponding minimum time is 4.868012 s. This study can provide a reference for improving the transmission efficiency of agricultural pest monitoring data, provide a guarantee for developing real-time and effective pest control strategies, and further reduce the threat of pest damage to the safety of farm products.
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  • 文章类型: Journal Article
    External temperature changes can detrimentally affect the properties of a microaccelerometer, especially for high-precision accelerometers. Temperature control is the fundamental method to reduce the thermal effect on microaccelerometer chips, although high-performance control has remained elusive using the conventional proportional-integral-derivative (PID) control method. This paper proposes a modified approach based on a genetic algorithm and fuzzy PID, which yields a profound improvement compared with the typical PID method. A sandwiched microaccelerometer chip with a measurement resistor and a heating resistor on the substrate serves as the hardware object, and the transfer function is identified by a self-built measurement system. The initial parameters of the modified PID are obtained through the genetic algorithm, whereas a fuzzy strategy is implemented to enable real-time adjustment. According to the simulation results, the proposed temperature control method has the advantages of a fast response, short settling time, small overshoot, small steady-state error, and strong robustness. It outperforms the normal PID method and previously reported counterparts. This design method as well as the approach can be of practical use and applied to chip-level package structures.
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  • 文章类型: Journal Article
    This paper proposes an optimization paradigm for structure design of curved-tube nozzle based on genetic algorithm. First, the mathematical model is established to reveal the functional relationship between outlet power and the nozzle structure parameters. Second, genetic algorithms transform the optimization process of curved-tube nozzle into natural evolution and selection. It is found that curved-tube nozzle with bending angle of 10.8°, nozzle diameter of 0.5 mm, and curvature radius of 8 mm yields maximum outlet power. Finally, we compare the optimal result with simulations and experiments of the rotating spinning. It is found that optimized curved-tube nozzle can improve flow field distribution and reduce the jet instability, which is critical to obtain high-quality nanofibers.
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  • 文章类型: Journal Article
    Based on recent studies, immunotherapy led by immune checkpoint inhibitors has significantly improved the patient survival rate and effectively reduced the recurrence risk. However, immunotherapy has different therapeutic effects for different patients, leading to difficulties in predicting the treatment response. Conversely, delta-radiomic features, which measure the difference between pre- and post-treatment through quantitative image features, have proven to be promising descriptors for treatment outcome prediction. Consequently, we developed an effective model termed as the automated multi-objective delta-radiomics (Auto-MODR) model for the prediction of immunotherapy response in metastatic melanoma. In Auto-MODR, delta-radiomic features and traditional radiomic features were used as inputs. Furthermore, a novel automated multi-objective model was developed to obtain more reliable and balanced results between sensitivity and specificity. We conducted extensive comparisons with existing studies on treatment outcome prediction. Our method achieved an area under the curve (AUC) of 0.86 in a cross-validation study and an AUC of 0.73 in an independent study. Compared with the model using conventional radiomic features (pre- and post-treatment) only, better performance can be obtained when conventional radiomic and delta-radiomic features are combined. Furthermore, Auto-MODR outperformed the currently available radiomic strategies.
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  • 文章类型: Journal Article
    In this paper, we present a method to automate the design of an efficient metasurface, which widens the bandwidth of the substrate. This strategy maximizes the potential of the substrate for the application of broad-band absorption. The design is achieved by utilizing the coding metasurface and a combination of two types of intelligent algorithms. First, inspired by the coding metasurface, a large number of structures are generated to act as potential metasurface unit patterns by randomly generating the associated binary codes. Then, the binary codes are directly substituted as optimization objects into a genetic algorithm to find the optimal metasurface. Finally, a neural network is introduced to replace the finite element analysis method to correlate the binary codes with the absorbing bandwidth. With the participation of neural networks, the genetic algorithm can find the optimal solution in a considerably short time. This method bypassed the prerequisite physical knowledge required in the process of metasurface design, which can be used for reference in other applications of the metasurface.
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