首页期刊导航|Applied Soft Computing
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Applied Soft Computing
Elsevier Science, B.V.
Applied Soft Computing

Elsevier Science, B.V.

1568-4946

Applied Soft Computing/Journal Applied Soft ComputingEIISTPSCIAHCI
正式出版
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    A novel improved SMA with quasi reflection operator: Performance analysis, application to the image segmentation problem of Covid-19 chest X-ray images

    Nama S.
    30页
    查看更多>>摘要:Slime mold algorithm (SMA) is a meta-heuristic optimization technique based on nature's slime module oscillation modes. Like other meta-heuristic algorithms, SMA is prone to poor diversity, local optima, and imbalanced exploitation abilities. A new, quasi-reflected slime mold (QRSMA) method, which combines the SMA algorithm with a quasi-reflection-based learning mechanism (QRBL), is presented to increase SMA's performance. The enhancement contains two parts: firstly, the QRBL mechanism was established to boost population variety early. Then, quasi-reflection-based jumping (QRBJ) was added to enhance convergence and avoid local optimum in each population update and to maintain the balance between exploitation and exploration. On the CEC20 benchmark functions of various kinds and dimensions, the performance of QRSMA was evaluated and checked that the proposed QRSMA's more robust search capabilities compared to the classic SMA and different search methodologies in terms of statistical, convergence, and diversity measurement. The findings reveal that QRSMA can significantly increase the convergence speed and solution precision of the basic SMA and others by comparing it with basic SMA and other algorithms. Two further tests have also been conducted to assess QRSMA performance. The first is the division of 10 natural gray pictures. Next, the QRSMA was evaluated for a real-world application, such as COVID-19 X-ray images. The region of interest inside the picture containing the characteristics of COVID-19 must be extracted to increase the precision of the classification. Four X-ray images have thus been utilized to assess QRSMA's performance. To evaluate the quality and performance of the QRSMA, comprehensive comparisons have also been carried out using different approaches. Overall test findings show that the QRSMA is an effective Multi-Level Thresholding (MLT) strategy superior to other current methods.

    SCSTCF: Spatial-Channel Selection and Temporal Regularized Correlation Filters for visual tracking

    Zhang J.Feng W.Yuan T.Sangaiah A.K....
    13页
    查看更多>>摘要:Recently, combining multiple features into discriminative correlation filters to improve tracking representation has shown great potential in object tracking. Existing trackers apply fixed weights to fuse features or fuse response maps, which cannot adapt to the object drift well. Moreover, in the tracking algorithm, using cyclic shift to obtain training samples always cause boundary effect, resulting in dissatisfied tracking effect. Therefore, we first design a multiple features fusion method. Various handcrafted features are fused with the same weight, then the fused handcrafted features and deep features are fused by adaptive weights, which considerably improves the representation ability of the tracking object. Second, we propose a correlation filter object function model called Spatial-Channel Selection and Temporal Regularized Correlation Filters. We perform the grouping features selection from the dimensions of channel, spatial and temporal, so as to establish the relevance between the multi-channel features and the correlation filter. Finally, we transform the objective function of the model with equality constraint to augmented Lagrangian multiplier formula without constraint, which is divided into three subproblems with closed-form solutions. The optimal solution is obtained by iteratively solving three subproblems using Alternating Direction Multiplier Method (ADMM). We conduct extensive experiments in four public datasets, OTB-2013, OTB-2015, TC128, UAV123, and VOT2016. The experimental results represent our proposed tracker performs favorably against other prevailing trackers in success rate and precision.

    A multimodal approach to chaotic renewable energy prediction using meteorological and historical information

    He R.Zhang D.Liu H.Dai W....
    17页
    查看更多>>摘要:Wind energy, which exhibits non-stationarity, randomness, and intermittency, is inextricably linked to meteorological data. The wind power series can be broken down into several subsequences using data decomposition techniques to make forecasting simpler and more accurate. Because of this, a single prediction model does not perform well in extracting hidden information from each subsequence. To predict different frequency series, this paper employed shallow and deep learning models and proposed an improved hybrid wind power prediction model based on secondary decomposition, extreme learning machines (ELM), convolutional neural networks (CNN), and bidirectional long short-term memory (BiLSTM). To begin, secondary decomposition was employed to break down the wind power series into several components. The ELM was used to forecast the low-frequency components. Following that, CNN was utilized to reintegrate the input characteristics of the high-frequency components, followed by BiLSTM prediction. Finally, the forecasting values for each component were added to generate the final prediction results. For one-, two-, and three-step predictions, the model was applied to the La Haute Borne wind farm. Additionally, four comparative experiments were conducted to validate the model's usefulness. The suggested model's mean absolute error (MAE), mean absolute percentage error (MAPE), and R-squared (R2) values for one-step prediction of the March data were 14.87 kW, 22.24 kW, and 0.984, respectively, which indicate the proposed model's superiority to other prediction models.

    Community-based anomaly detection using spectral graph filtering

    Francisquini R.Nascimento M.C.V.Lorena A.C.
    13页
    查看更多>>摘要:Several applications have a community structure where the nodes of the same community share similar attributes. Anomaly or outlier detection in networks is a relevant and widely studied research topic with applications in various domains. Despite a significant amount of anomaly detection frameworks, there is a dearth on the literature of methods that consider both attributed graphs and the community structure of the networks. This paper proposes a community-based anomaly detection algorithm using a spectral graph-based filter that includes the network community structure into the Laplacian matrix adopted as the basis for the Fourier transform. In addition, the choice of the cutoff frequency of the filter considers the number of communities found. In computational experiments, the proposed strategy, called SpecF, showed an outstanding performance in successfully identifying even discrete anomalies. SpecF is better than a baseline disregarding the community structure, especially for networks with a higher community overlapping. Additionally, we present a case study to validate the proposed method to study the dissemination of COVID-19 in the different districts of S?o José dos Campos, Brazil.

    Churn prediction in digital game-based learning using data mining techniques: Logistic regression, decision tree, and random forest

    Kiguchi M.Saeed W.Medi I.
    20页
    查看更多>>摘要:Educational Technology (EdTech) is an industry that integrates education and technology advances. Digital game-based learning (DGBL) is one of the narrowed-down categories of EdTech. One of the common issues in the EdTech market is the higher churn rate. However, because the DGBL market is still in the early stage, few studies related to marketing perspectives exist. Besides, the approach in education or online gaming industries can be only partially applicable to DGBL. A popular approach for addressing a higher churn rate is churn prediction. By using a dataset from a Japanese company providing DGBL services, this work proposes an approach for the combination of defining churn and churn prediction for DGBL. This work has three objectives. First, determining churn in DGBL by comparing the recency and the addition of average and two standard deviations of user inactive time. Second, clarifying the churn rate of the Japanese service, which became evident as 56.77% by using the newly created churn definition. Third, developing a churn prediction model by comparing logistic regression (LR), decision tree, and random forest models. Feature selection, dataset split ratio comparison, and hyperparameter tuning were conducted to achieve better predictions. Based on the results, LR scored the highest AUC of 0.9225 and an F1-score of 0.9194. These results are on the higher side comparing with the past churn prediction studies in online gaming and education industries. As a consequence, the results indicate the effectiveness of the proposed approach for churn determination and prediction in DGBL.

    Solving time varying many-objective TSP with dynamic θ-NSGA-III algorithm

    Gupta R.Nanda S.J.
    26页
    查看更多>>摘要:Dynamic many-objective traveling salesman problem (DMaTSP) has a lot of applications in routing challenges. The problem environment describe how the layout and number of cities involve in TSP varies over time. In this manuscript a sixteen cities DMaTSP problem is addressed with four fitness objectives: successive minimum distance between the cities, diametric minimum distance between cities and maximizing associated letters and gifts, which varies over six time periods. The paper introduce a prediction-based dynamic many-objective optimization technique termed as Dynamic θ-non-dominated Sorting Genetic Algorithm III (Dθ-NSGA-III). The algorithm θ-NSGA-III, is based on the fundamentals of popular NSGA-III combined with vector angle-based evolutionary algorithm (VaEA). When a change occurs in the problem environment, the prediction set is used to generate the new population, to achieve faster convergence to the new global optimum. Four prediction strategies based on support vector regression (SVR) with linear kernel and radial basis function (RBF) kernel, polynomial interpolation, and cubic spline-based prediction are used for analysis. The validation of the Dθ-NSGA-III algorithm has been carried out on sixteen benchmark functions taken from DIMP, G, JY and DF Test suites. Comparative analysis have been carried out with dynamic algorithms of NSGA-III, MOEA/D, MRP-MOEA and DNSGA-II algorithms. The simulation analysis reveals superior performance of Dθ-NSGA-III with RBF kernel over the benchmark test suites as well as DMaTSP problem in the form of Mean of IGD, Shott's Spacing, Max. Spread metrics. The proposed Dθ-NSGA-III with prediction approaches solve dynamic many-objective optimization problems with effective run time bit higher than DNSGA-III but lower than DMOEA/D and MRP-MOEA based approach.

    A decomposition-based constrained multi-objective evolutionary algorithm with a local infeasibility utilization mechanism for UAV path planning

    Peng C.Qiu S.
    11页
    查看更多>>摘要:Unmanned Aerial Vehicle (UAV) path planning problems can be treated as constrained multi-objective optimization problems, which often have complicated constraints in real-world scenarios. Algorithms for solving them require a powerful constraint-handling technique to utilize infeasible information. However, this has seldom been explored in this field. To remedy this issue, this paper proposes a decomposition-based constrained multi-objective evolutionary algorithm (M2M-DW) with a local infeasibility utilization mechanism for UAV path planning. Therein, M2M-DW is adopted as a solution optimizer since it can utilize infeasible individuals. However, this may result in poor performance due to the arbitrary use of infeasible individuals. To solve this issue, a local infeasibility utilization mechanism is proposed to effectively utilize the infeasible information. Besides, an improved mutation scheme is designed to further explore the promising regions. Experimental studies are conducted on three sets of UAV path planning problems with different difficulties, and the results highlight the effectiveness of the proposed algorithm in terms of reliability and stability in finding a set of feasible optimal solutions.

    Human-like motion planning of autonomous vehicle based on probabilistic trajectory prediction

    Li P.Zhou X.Xu J.Chen Z....
    14页
    查看更多>>摘要:Motion planning for autonomous vehicles becomes more challenging when both driver comfort and collision risk are considered. To overcome this challenge, a human-like motion planning strategy based on the probabilistic prediction in a dynamic environment is proposed. In this study, it is mainly concerned with the following three aspects: the probabilistic prediction of states of the surrounding vehicles, decision making of the optimal path with a cost function and speed planning based on the driver's target speed. Firstly, the path generation is realized based on a fifth-degree polynomial and the desired path is optimized by a cost function with four performance indices, i.e., safety, consistency, smoothness, and distance from local path to global path. Secondly, collision detection is analyzed regarding the host vehicle and surrounding vehicles aspects. For the host vehicle, a path-tracking error relating to vehicle speed and road curvature is taken into account. For the surrounding vehicles, the probabilistic trajectory prediction is made by using the structural Long-Short Term Memory (LSTM) network. Next, the collision probability is assessed using the Monte Carlo method and the optimal path is selected through the probability threshold depending on driver styles such as a conservative or aggressive driver. Moreover, the human-like speed planning for longitudinal motion is implemented considering driver target speed in vehicle following and vehicle cut-in situations. Finally, the proposed human-like motion planning algorithm has been validated via Hardware-in-the-loop (HIL) tests. The simulation results have shown the effectiveness of dynamic obstacle avoidance with global path-tracking and speed-tracking with driver comfort. Parameter sensitivity analysis for cost function and speed planner is then performed. The sensitivity analysis and the results also illustrate the influence degree of various parameters on the planned trajectory, which would be conducive to further improving the algorithm performance in the future. With an appropriate selection of the weight ratio between safety and comfort proposed in this work, it is found that the driver's comfort acceptance will be improved compared with the traditional deterministic motion planning algorithm.

    A study of multi-objective restricted multi-item fixed charge transportation problem considering different types of demands

    Biswas A.Cardenas-Barron L.E.Cespedes-Mota A.Shaikh A.A....
    16页
    查看更多>>摘要:In this paper, we formulate a multi-objective fixed charge transportation problem (FCTP) for multiple items, considering availability of multiple modes of transport along each pair of origin and destination. The variable cost of each item, the fixed cost and the transport time are considered to be different for each mode of transport. It is also considered that some items are mutually incompatible and cannot be transported in the same mode of transport. Two models of the multi-item FCTP are presented, considering the demands of items as crisp and interval numbers, respectively. The transportation problem is then posed as a multi-objective optimization problem (MOOP), in which the objectives are to minimize the total cost and total transport time. For the model with interval demands, the instances are only solved, in which, for each item, the sum total of demands of an item at different destinations is at least the sum total of availabilities of the item at different origins. For each model, a set of four numerical examples are solved using two multi-objective evolutionary algorithms (MOEAs), namely, Non-dominated Soring Genetic Algorithm-II (NSGA-II) and Strength Pareto Evolutionary Algorithm 2 (SPEA2). A comparative study of the computational results are made in terms of four performance index, namely, RNI value, Hyper-volume (HV), Inverted Generational Distance (IGD) and Spread. The computational results clearly indicates that NSGA-II outperforms SPEA2 for all the numerical examples, in terms of generating better approximate Pareto front with respect to dominance, diversity and spread.

    Multi-dimensional recurrent neural network for remaining useful life prediction under variable operating conditions and multiple fault modes

    Cheng Y.Wang C.Wu J.Zhu H....
    12页
    查看更多>>摘要:Data-driven remaining useful life (RUL) prediction approaches, especially those based on deep learning (DL), have been increasingly applied to mechanical equipment. However, two reasons limit their prognostic performance under variable operating conditions. The first one is that the existing DL-based prognostic models usually ignore the utilization of operating condition data. And, the other is that most DL-based prognostic models focus on enhancing the nonlinear representation learning ability by stacking network layers, and lack exploration in extracting diverse features. To break through the limitation of prediction accuracy under variable operating conditions, this paper presents a novel multi-dimensional recurrent neural network (MDRNN) for RUL prediction under variable operating conditions and multiple fault modes (VOCMFM). Different from existing DL prognostic models, MDRNN can simultaneously model and mine multisensory monitoring data and operating condition data to achieve RUL prediction under VOCMFM. In MDRNN, parallel bidirectional long short-term memory and bidirectional gated recurrent unit pathways are constructed to automatically capture degradation features from different dimensions. Two prognostic benchmarking datasets of aircraft turbofan are adopted to validate MDRNN. Experimental results demonstrate that MDRNN can perform the prediction tasks under VOCMFM well and surpass many state-of-the-arts.