Artificial neural networks

人工神经网络
  • 文章类型: Journal Article
    人工神经网络为评估和理解重金属的存在和浓度提供了可行的途径,这些重金属可能在生态系统可持续性的水质预测的更广泛背景下引起危险的并发症。为了估算伊兹尼克湖的重金属浓度,是周边社区的重要水源,表征数据来自2015年至2021年流入湖泊的五种不同水源。使用IBMSPSSStatistics23软件评估这些表征结果,随着湖泊水质系统的加入。为此,在卡拉苏测量和监测了七个不同的物理化学参数,克兰德尔,Olukdere和Sölöz水源流入湖中,作为输入数据。源自湖泊的Karsak流中15种不同重金属的浓度水平作为输出。具体来说,Sn代表Karasu(0.999),Sb代表Kºrandere(1.000),Olukdere的Cr(1.000)和Sölöz的Pb和Se(0.995)表明参数估计R2系数接近1.000。Sn是具有最佳估算前景的常见重金属参数。鉴于自变量在估计重金属污染中的重要性,电导率,COD,CODCOD和温度是Karasu最有效的参数,Olukdere,克兰德尔和索洛兹,分别。ANN模型是一种很好的预测工具,可以有效地用于确定湖泊中的重金属污染,作为保护伊兹尼克湖的水收支和消除现有污染的努力的一部分。
    Artificial neural networks offer a viable route in assessing and understanding the presence and concentration of heavy metals that can cause dangerous complications in the wider context of water quality prediction for the sustainability of the ecosystem. In order to estimate the heavy metal concentrations in Iznik Lake, which is an important water source for the surrounding communities, characterization data were taken from five different water sources flowing into the lake between 2015 and 2021. These characterization results were evaluated with IBM SPSS Statistics 23 software, with the addition of the lake water quality system. For this purpose, seven distinct physicochemical parameters were measured and monitored in Karasu, Kırandere, Olukdere and Sölöz water sources flowing into the lake, to serve as input data. Concentration levels of 15 distinct heavy metals in Karsak Stream originating from the lake were as the output. Specifically, Sn for Karasu (0.999), Sb for Kırandere (1.000), Cr for Olukdere (1.000) and Pb and Se for Sölöz (0.995) indicate parameter estimation R2 coefficients close to 1.000. Sn stands out as the common heavy metal parameter with best estimation prospects. Given the importance of the independent variable in estimating heavy metal pollution, conductivity, COD, COD and temperature stood out as the most effective parameters for Karasu, Olukdere, Kırandere and Sölöz, respectively. The ANN model emerges as a good prediction tool that can be used effectively in determining the heavy metal pollution in the lake as part of the efforts to protect the water budget of Lake Iznik and to eliminate the existing pollution.
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  • 文章类型: Journal Article
    侧流测定法已广泛用于检测2019年冠状病毒病(COVID-19)。侧流测定由硝化纤维素(NC)膜组成,必须具有特定的侧向流速才能使蛋白质发生反应。芯吸速率通常用作评估膜中横向流动的方法。我们使用多元回归和人工神经网络(ANN)根据膜配方数据预测NC膜的芯吸速率。开发的ANN以均方误差0.059预测芯吸率,而多元回归的平方误差为0.503。该研究还通过从扫描电子显微镜获得的图像强调了水含量对芯吸速率的显着影响。这项研究的发现可以显着降低具有特定芯吸率的新型NC膜的研发成本,因为该算法可以根据膜配方预测芯吸速率。
    Lateral flow assays have been widely used for detecting coronavirus disease 2019 (COVID-19). A lateral flow assay consists of a Nitrocellulose (NC) membrane, which must have a specific lateral flow rate for the proteins to react. The wicking rate is conventionally used as a method to assess the lateral flow in membranes. We used multiple regression and artificial neural networks (ANN) to predict the wicking rate of NC membranes based on membrane recipe data. The developed ANN predicted the wicking rate with a mean square error of 0.059, whereas the multiple regression had a square error of 0.503. This research also highlighted the significant impact of the water content on the wicking rate through images obtained from scanning electron microscopy. The findings of this research can cut down the research and development costs of novel NC membranes with a specific wicking rate significantly, as the algorithm can predict the wicking rate based on the membrane recipe.
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  • 文章类型: Journal Article
    装配线效率是决定制造企业整体效率的重要参数之一。产品在最佳条件下的生产是由一个平衡的组件保证。有了平衡的装配线,机械,材料和劳动力成本降低。在本研究范围内,获取了一家生产紧急灯具的公司的日常生产能力和装配线效率的真实数据,用4种不同的启发式ALB方法对同一装配线进行平衡,并对结果进行了比较。根据获得的结果,使用霍夫曼实现了93.955%的高生产线效率,Comsoal和Moodie&Young(M&Y)方法,用排名位置权重(RPW)方法获得84.414%。因此,据观察,日生产能力从250台增加到375台。作为研究的结果,据透露,现有装配线的效率和相应的日常生产能力增加。此外,该装配线的研究结果被教授给人工神经网络模型进行训练,并获得了不同装配线的工作站结果,精度为99.940。在这种情况下,已经发现,除了使用启发式方法外,还可以使用人工神经网络方法来解决ALB问题。
    Assembly line efficiency is one of the most important parameters that determine the overall efficiency of a manufacturing company. The production of a product under optimum conditions is ensured by a balanced assembly. With a balanced assembly line, machinery, material and labour costs are reduced. Within the scope of this research, real data about the daily production capacity and assembly line efficiency of a company producing Emergency Luminaire were taken, the same assembly line was balanced with 4 different Heuristic ALB methods and the results were compared. According to the results obtained, a high line efficiency of 93.955% was achieved using the Hoffman, Comsoal and Moodie&Young (M&Y) methods, and 84.414% was achieved with the Ranked Positional Weight (RPW) method. As a result of this, it was observed that the daily production capacity increased from 250 units to 375 units. As a result of the study, it was revealed that the efficiency of the existing assembly line and accordingly the daily production capacity increased. In addition, the study results of this assembly line were taught to an artificial neural network model for training purposes, and the work station results of the operations of a different assembly line were obtained with 99.940 accuracy. In this context, it has been revealed that the artificial neural networks method can be used in addition to the use of the heuristic method in the solution of ALB problems.
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  • 文章类型: Journal Article
    人工神经网络(ANN)如何为认知科学提供信息?认知科学家通常使用人工神经网络,但不检查其内部结构。在本文中,我们使用人工神经网络来探索认知如何代表音乐属性。我们训练人工神经网络对音乐和弦进行分类,我们解释网络结构,以确定神经网络发现和使用什么表示。我们发现输入单元和隐藏单元之间的连接权重可以使用傅立叶相空间来描述,在音乐集理论中研究的表征。我们发现通过这些加权连接权重的总信号是两个傅立叶结构之间相似性的度量:隐藏单元权重的结构和刺激的结构。这是令人惊讶的,因为这些傅立叶结构都不是由隐藏单元计算的。然后,我们展示输出单元如何使用这种相似性度量来对和弦进行分类。然而,我们还发现不同类型的单位-使用不同激活函数的单位-使用这种相似性度量非常不同。这个结果,结合其他发现,表明虽然我们的网络与音乐集的傅立叶分析有关,他们不执行通常在音乐集理论中描述的那种傅立叶分析。我们的结果表明,音乐的傅立叶表示不限于音乐集理论。我们的结果还表明认知心理学家如何探索音乐认知中的傅立叶表示。严重的,这种理论和经验含义要求研究人员了解网络结构如何将刺激转化为反应。
    How might artificial neural networks (ANNs) inform cognitive science? Often cognitive scientists use ANNs but do not examine their internal structures. In this paper, we use ANNs to explore how cognition might represent musical properties. We train ANNs to classify musical chords, and we interpret network structure to determine what representations ANNs discover and use. We find connection weights between input units and hidden units can be described using Fourier phase spaces, a representation studied in musical set theory. We find the total signal coming through these weighted connection weights is a measure of the similarity between two Fourier structures: the structure of the hidden unit\'s weights and the structure of the stimulus. This is surprising because neither of these Fourier structures is computed by the hidden unit. We then show how output units use such similarity measures to classify chords. However, we also find different types of units-units that use different activation functions-use this similarity measure very differently. This result, combined with other findings, indicates that while our networks are related to the Fourier analysis of musical sets, they do not perform Fourier analyses of the kind usually described in musical set theory. Our results show Fourier representations of music are not limited to musical set theory. Our results also suggest how cognitive psychologists might explore Fourier representations in musical cognition. Critically, such theoretical and empirical implications require researchers to understand how network structure converts stimuli into responses.
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  • 文章类型: Journal Article
    尽管流动调制综合二维气相色谱(FM-GG×GC)在不同的研究领域得到了广泛的应用,在手性分离领域的应用非常有限。从实践的角度来看,在这种情况下,建立对映体分离的实验参数可能要求更高。由于载气在两个维度上流动,它不仅影响分离参数,但也填充/冲洗体积的调制器和它的工作效率。在这种情况下,应用多变量实验设计来找到反向填充/冲洗(RFF)调节剂的最佳实验参数,该调节剂用于对映体分离瓶化葡萄酒样品中存在的有机化合物。用响应面方法和人工神经网络(ANN)描述了结果。存在于瓶装葡萄酒中的手性化合物的对映体组成用于确定其地理来源,通过主成分分析(PCA)。此外,开发的一类偏最小二乘(OC-PLS)模型能够识别来自Tokaj葡萄酒产区的葡萄酒样品,在存在其他样品的情况下,其有效性为93%.
    In spite of extensive applications of flow modulated comprehensive two-dimensional gas chromatography (FM-GG × GC) in different research areas, its application in the field of chiral separation is very limited. From a practical point of view, the establishment of experimental parameters for enantiomer separations is possibly more demanding in this case. Since the carrier gas flows in both dimensions, it affects not only the separation parameters, but also the fill/flush volumes of the modulator and its working efficiency. In this context, a multivariate design of experiment was applied to find the optimum experimental parameters of a reversed fill/flush (RFF) modulator for enantiomer separation of organic compounds present in botrytized wine samples. The results were described both with response surface methodology and artificial neural networks (ANN). The enantiomeric composition of chiral compounds present in the botrytized wines was used to identify their geographical origin, by principal component analysis (PCA). In addition, the developed one-class partial least squares (OC-PLS) model enabled recognition of the wine samples from the Tokaj wine region with 93% effectiveness in the presence of other samples.
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  • 文章类型: Journal Article
    本研究旨在适应土壤和流域评估工具(SWAT),广泛使用的分水岭模型,通过考虑含水层的补给,以地下水为主的地表水体。以阿拉巴马州沿海平原地区的上游斜坡湿地的实测流量为例,我们提出了挑战和使用SWAT模型预测排水流域流量的相对简单的方法,以及模拟地下水上升流的相对简单的方法。研究流域的SWAT模拟流量受到降水的限制,因此,模拟流量比观测流量小几倍。因此,我们的第一种方法涉及单独的暴雨径流和基流校准,包括使用观测基流和模拟基流之间的回归关系(ENASH=0.67).我们的下一个方法是通过限制深层损失的范围,使SWAT适应模拟上升流地下水排放,而不是深层含水层损失。β深度参数,至负值(ENASH=0.75)。最后,我们还研究了将人工神经网络(ANN)与SWAT结合使用,以进一步提高校准性能.这种方法使用SWAT校准的流量,蒸散,和降水作为人工神经网络的输入(ENASH=0.88)。本研究中研究的方法可用于在其他地下水主导流域中导航类似的流量校准挑战,这对于管理者和建模者来说都是非常有用的工具。
    This study aims to adapt the Soil and Watershed Assessment Tool (SWAT), a ubiquitously used watershed model, for ground-water dominated surface waterbodies by accounting for recharge from the aquifers. Using measured flow to a headwater slope wetland in Alabama\'s coastal plain region as a case study, we present challenges and relatively simple approaches in using the SWAT model to predict flows from the draining watershed and relatively simple approaches to model groundwater upwelling. SWAT-simulated flow at the study watershed was limited by precipitation, and consequently, simulated flows were several times smaller in magnitude than observed flows. Thus, our first approach involved a separate stormflow and baseflow calibration which included the use of a regression relationship between observed and simulated baseflow (E NASH = 0.67). Our next approach involved adapting SWAT to simulate upwelling groundwater discharge instead of deep aquifer losses by constraining the range of deep losses, β deep parameter, to negative values (E NASH = 0.75). Finally, we also investigated the use of artificial neural networks (ANN) in conjunction with SWAT to further improve calibration performance. This approach used SWAT-calibrated flow, evapotranspiration, and precipitation as inputs to ANN (E NASH = 0.88). The methods investigated in this study can be used to navigate similar flow calibration challenges in other groundwater dominant watersheds which can be very useful tool for managers and modelers alike.
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  • 文章类型: Journal Article
    3D打印过程中材料特性演变的复杂性和非线性性质继续使熔融沉积建模(FDM)的实验优化成本高昂,因此需要发展数学预测模型。本文提出了一种基于有限数据实验与黑盒AI建模耦合,然后进行启发式优化的两阶段方法,以提高FDM加工的丙烯腈-丁二烯-苯乙烯(ABS)的粘弹性能。选定工艺参数的影响(包括喷嘴温度,图层高度,光栅方向和沉积速度)及其组合效应也进行了研究。具体来说,第一步,采用Taguchi正交阵列以最少的运行次数设计动态力学分析(DMA)实验,同时考虑最终打印的不同工作条件(温度)。使用Lenth的统计方法测量了工艺参数的显著性。注意到FDM参数的组合效应是高度非线性和复杂的。接下来,人工神经网络被训练来预测3D打印样本的存储和损耗模量,因此,通过粒子群优化(PSO)对工艺参数进行优化。打印的优化过程显示总体上更接近父(未加工)ABS的行为,与未优化的设置相比。
    The complex and non-linear nature of material properties evolution during 3D printing continues to make experimental optimization of Fused Deposition Modeling (FDM) costly, thus entailing the development of mathematical predictive models. This paper proposes a two-stage methodology based on coupling limited data experiments with black-box AI modeling and then performing heuristic optimization, to enhance the viscoelastic properties of FDM processed acrylonitrile butadiene styrene (ABS). The effect of selected process parameters (including nozzle temperature, layer height, raster orientation and deposition speed) as well as their combinative effects are also studied. Specifically, in the first step, a Taguchi orthogonal array was employed to design the Dynamic Mechanical Analysis (DMA) experiments with a minimal number of runs, while considering different working conditions (temperatures) of the final prints. The significance of process parameters was measured using Lenth\'s statistical method. Combinative effects of FDM parameters were noted to be highly nonlinear and complex. Next, artificial neural networks were trained to predict both the storage and loss moduli of the 3D printed samples, and consequently, the process parameters were optimized via Particle Swarm Optimization (PSO). The optimized process of the prints showed overall a closer behavior to that of the parent (unprocessed) ABS, when compared to the unoptimized set-up.
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  • 文章类型: Journal Article
    The geophysical investigation of dambo groundwater reserves using electrical resistivity methods was conducted in Linthipe 4B sub basin in Central region of Malawi. With the increasing over-utilization of shallow wells in dambos for smallholder irrigation, this study was carried out to investigate whether dambo groundwater reserves could serve as sustainable irrigation water sources and to examine the aquifer characteristics in Linthipe sub basin. Vertical Electrical Sounding (VES) points were established in the basin using the Schlumberger configuration array. Data was analysed using IPI2win and Surfer software applications. Contrary to other commercial software applications which are costly for government departments when analysing geophysical data, partial curve matching and one dimensional (1-D) computer iteration techniques were used to interpret the VES curves and the pseudo-cross section resistivity profiles due to their simplicity and cost-effectiveness. The study has revealed that the aquifer properties in the basin are exceptionally variable in terms of state of weathering, depth, thickness, lithology, aquifer recharge configuration, geologic material and hydraulic gradients. These variations showed that the shallow wells in the basin have significant fractures suggesting high water potential for climate smart irrigation usage in the study area. The potential groundwater zones for climate smart irrigated farming were detected at VES 1, 2, 3, 4, 5 and 6 noted by low aquifer resistivity with high values of aquifer thickness. However, VES points, 7, 8 and 9 were likely to be zones of low water bearing potential because they had high values of aquifer resistivity with low aquifer thickness. The findings also validated the effectiveness, timeliness, and efficiency of using vertical electrical resistivity technique in exploring groundwater for irrigation. The results from this study have highlighted that feasible shallow well depth for a sustainable irrigation system is a function of geologic resistance and aquifer thickness when the geologic material has low resistance and broader thickness. This study noted that knowledge of aquifer recharge rates in dambos is required in order to effectively control abstraction rates for sustainable irrigation in basins. There is a need to promote the usage of geophysical studies, reforestation, river basin management trainings and aquifer recharge technologies in exploring sites for shallow well development for irrigation. The study further recommends the usage of geographical information systems (GIS) and Artificial Intelligence (AI) in improving the results of groundwater monitoring studies in Malawi.
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  • 文章类型: Journal Article
    Existing methods for spatial quantification of grassland utilization intensity cannot meet the demand for accurate detection of the spatial distribution of grassland utilization intensity in the Qinghai-Tibetan Plateau with high spatial resolution. In this paper, a method based on remote-sensing observations and simulations of grassland growth dynamics is proposed. The grassland enhanced vegetation index (EVI) time-series curve during the growing season characterizes the growth of grassland in the corresponding pixel; The deviation between the observed and potential EVI curves indicates the disturbance on grassland growth imposed by human activities, and it can characterize the grassland utilization intensity during the growing season. Based on the main idea described above, absolute and relative disturbances are calculated and used as quantitative indicators of grassland utilization intensity defined from different perspectives. Livestock amount at the pixel scale is obtained by pixel-by-pixel calculations based on the function relationship at the township scale between absolute disturbance and livestock density, which is specific quantitative indicator that considers the mode of grassland utilization. In simulating the potential EVI of grassland, the lag and accumulation effects of meteorological factors are investigated at the daily scale using a multi-objective genetic algorithm. Further, the nonlinear functions between multiple environmental factors (e.g., grassland type, topography, soil, meteorology) and the grassland EVI are established using an error back-propagation feedforward artificial neural network (ANN-BP) with parameter optimization. Finally, the potential EVIs of all grassland pixels are simulated on the basis of this model. The method is applied to the Selinco basin on the Qinghai-Tibetan Plateau and validated by examining the spatial consistency of the results with township-scale livestock density and grazing pressure. The final results indicate that the proposed method can accurately detect the spatial distribution of grassland utilization intensity which is appliable in the similar regions.
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  • 文章类型: Journal Article
    This study aims to produce accurate predictions of the NO2 concentrations at a specific station of a monitoring network located in the Bay of Algeciras (Spain). Artificial neural networks (ANNs) and sequence-to-sequence long short-term memory networks (LSTMs) were used to create the forecasting models. Additionally, a new prediction method was proposed combining LSTMs using a rolling window scheme with a cross-validation procedure for time series (LSTM-CVT). Two different strategies were followed regarding the input variables: using NO2 from the station or employing NO2 and other pollutants data from any station of the network plus meteorological variables. The ANN and LSTM-CVT exogenous models used lagged datasets of different window sizes. Several feature ranking methods were used to select the top lagged variables and include them in the final exogenous datasets. Prediction horizons of t + 1, t + 4 and t + 8 were employed. The exogenous variables inclusion enhanced the model\'s performance, especially for t + 4 (ρ ≈ 0.68 to ρ ≈ 0.74) and t + 8 (ρ ≈ 0.59 to ρ ≈ 0.66). The proposed LSTM-CVT method delivered promising results as the best performing models per prediction horizon employed this new methodology. Additionally, per each parameter combination, it obtained lower error values than ANNs in 85% of the cases.
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