Commodity recommendation contributes an important part of individuals’ daily life. In this context, deep reinforcement learning methods have demonstrated substantial efficacy in enhancing recommender systems’ performance. Nevertheless, several recommender systems directly utilize original feature information as a foundational element for decision-making, which seems simplistic and low efficient. Furthermore, the incorporation of sequential decision-making adds complexity to the task of recommendation. In pursuit of maximizing the long-term sequential returns of recommender systems, our study introduces a novel architecture, named User Information Separating Architecture (UISA). This framework is tailored to align with classic reinforcement learning algorithms and aims to extract the user’s interest value through the discrete processing of both static and dynamic user information. Through integration with deep reinforcement learning, the architecture is oriented towards the maximization of long-term profit and is applicable in sequential recommendation scenarios. We conduct experimental assessments by combining the proposed architecture with proximal policy optimization (PPO) and deep deterministic policy gradient (DDPG) algorithms. The outcomes illustrate marked improvements in commodity recommendation, showcasing enhancements ranging from approximately 5% to 40% in both reward and click-through rate metrics across a self-constructed JDEnv environment and the Virtual Taobao environment. Through comparison experiments, the UISA models demonstrate comparable performance.

Widespread adoption of online recruitment platforms has led to explosive growth in employment information, resulting in an ever-increasing demand from job seekers for accurate and effective job recommendations. Existing studies on the Person-Job Fit models focus on the correlation between resumes and job descriptions, with rare consideration given to user historical behavior such as click and application. On the contrary, job recommendation methods always ignore the crucial information lurking in the resume text. In addition, the continuous influx of a vast amount of job data poses challenges to the updating of online recommendation results. To this end, we propose a novel O nline J ob R ecommendation model via R esume F usion (OJRRF) in this article, aimed at making accurate and efficient online job recommendations with the merits of addressing job cold start and long tail problems. The key contribution lies in two facets: (1) incorporating resume text information into the knowledge graph attention framework to enhance job seekers’ vector representations jointly; (2) designing a hybrid recommender strategy by combining the knowledge-aware offline model with the content-based online model. Finally, we conducted extensive comparison experiments and online A/B test on the recruitment platform of JiuYeJie big data company to validate the effectiveness and real-time capability of OJRRF. The release code can be found in https://github.com/urnotada/OJRRF .

Nonconvex optimization issues are prevalent in machine learning and data science. While gradient-based optimization algorithms can rapidly converge and are dimension-independent, they may, unfortunately, fall into local optimal solutions or saddle points. In contrast, evolutionary algorithms (EAs) gradually adapt the population of solutions to explore global optimal solutions. However, this approach requires substantial computational resources to perform numerous fitness function evaluations, which poses challenges for high-dimensional optimization in particular. This study introduces a novel nonconvex optimization algorithm, the niching-based gradient-directed evolution (NGDE) algorithm, designed specifically for high-dimensional nonconvex optimization. The NGDE algorithm generates potential solutions and divides them into multiple niches to explore distinct areas within the feasible region. Subsequently, each individual creates candidate offspring using the gradient-directed mutation operator we designed. The convergence properties of the NGDE algorithm are investigated in two scenarios: accessing the full gradient and approximating the gradient with mini-batch samples. The experimental studies demonstrate the superior performance of the NGDE algorithm in minimizing multimodal optimization functions. Additionally, when applied to train the neural networks of LeNet-5, NGDE shows significantly improved classification accuracy, especially in smaller training sizes.

Generating accurate and concise headlines based on news content can help people filter out interesting content and improve the quality of life. News headline generation, as the sub-application area of text summarization, has many methodological commonalities but with higher requirements for generated text quality, which is more challenging. In this paper, we propose a new model to generate news headline, named RADGen (REIN-FORCE Aided Deep Generator for news headline), which combines a Transformer-based generator with a sentence-selecting filter based on REINFORCE algorithm. We perform experiments and assessments on Chinese news headline dataset, which achieve 25.71, 8.26 and 23.58 for f-score of ROUGE-1, ROUGE-2 and ROUGE-L respectively, to demonstrate the effectiveness of the proposed model. In addition, ablation experiments show the positive roll of reinforcement learning filter in news headline generation.

Credit risk assessment plays a key role in determining the banking policies and commercial strategies of financial institutions. Ensemble learning approaches have been validated to be more competitive than individual classifiers and statistical techniques for default prediction. However, most researches focused on improving overall prediction accuracy rather than improving the identification of actual defaulted loans. In addition, model interpretability has not been paid enough attention in previous studies. To fill up these gaps, we propose a Multi-layer Multi-view Stacking Integration (MLMVS) approach to predict default risk in the P2P lending scenario. As the main innovation, our proposal explores multi-view learning and soft probability outputs to produce multi-layer integration based on stacking. An interpretable artificial intelligence tool LIME is embedded for interpreting the prediction results. We perform a comprehensive analysis of MLMVS on the Lending Club dataset and conduct comparative experiments to compare it with a number of well-known individual classifiers and ensemble classification methods, which demonstrate the superiority of MLMVS.

Ordinal regression has been widely used in applications, such as credit portfolio management, recommendation systems, and ecology, where the core task is to predict the labels on ordinal scales. Due to its learning efficiency, online ordinal regression using passive aggressive (PA) algorithms has gained a much attention for solving large-scale ranking problems. However, the PA method is sensitive to noise especially in the scenario of streaming data, where the ranking of data samples may change dramatically. In this paper, we propose a noise-resilient online learning algorithm using the Ramp loss function, called PA-RAMP, to improve the performance of PA method for noisy data streams. Also, we validate the order preservation of thresholds of the proposed algorithm. Experiments on real-world data sets demonstrate that the proposed noise-resilient online ordinal regression algorithm is more robust and efficient than state-of-the-art online ordinal regression algorithms.

Least absolute shrinkage and selection operator (LASSO) is one of the most commonly used methods for shrinkage estimation and variable selection. Robust variable selection methods via penalized regression, such as least absolute deviation LASSO (LAD-LASSO), etc., have gained growing attention in works of literature. However those penalized regression procedures are still sensitive to noisy data. Furthermore, “concept drift” makes learning from streaming data fundamentally different from the traditional batch learning. Focusing on the shrinkage estimation and variable selection tasks on noisy streaming data, this paper presents a noise-resilient online learning regression model, i.e. canal-LASSO. Comparing with the LASSO and LAD-LASSO, canal-LASSO is resistant to noisy data in both explanatory variables and response variables. Extensive simulation studies demonstrate satisfactory sparseness and noise-resilient performances of canal-LASSO.

In a conventional supervised learning paradigm, each data instance is associated with one single class label. Multilabel learning differs in the way that data instances may belong to multiple concepts simultaneously, which naturally appear in a variety of high impact domains, ranging from bioinformatics and information retrieval to multimedia analysis. It targets leveraging the multiple label information of data instances to build a predictive learning model that can classify unlabeled instances into one or multiple predefined target classes. In multilabel learning, even though each instance is associated with a rich set of class labels, the label information could be noisy and incomplete as the labeling process is both time consuming and labor expensive, leading to potential missing annotations or even erroneous annotations. The existence of noisy and missing labels could negatively affect the performance of underlying learning algorithms. More often than not, multilabeled data often has noisy, irrelevant, and redundant features of high dimensionality. The existence of these uninformative features may also deteriorate the predictive power of the learning model due to the curse of dimensionality. Feature selection, as an effective dimensionality reduction technique, has shown to be powerful in preparing high-dimensional data for numerous data mining and machine-learning tasks. However, a vast majority of existing multilabel feature selection algorithms either boil down to solving multiple single-labeled feature selection problems or directly make use of the imperfect labels to guide the selection of representative features. As a result, they may not be able to obtain discriminative features shared across multiple labels. In this article, to bridge the gap between a rich source of multilabel information and its blemish in practical usage, we propose a novel noise-resilient multilabel informed feature selection framework (MIFS) by exploiting the correlations among different labels. In particular, to reduce the negative effects of imperfect label information in obtaining label correlations, we decompose the multilabel information of data instances into a low-dimensional space and then employ the reduced label representation to guide the feature selection phase via a joint sparse regression framework. Empirical studies on both synthetic and real-world datasets demonstrate the effectiveness and efficiency of the proposed MIFS framework.

Batch-mode least squares support vector machine (LSSVM) is often associated with unbounded number of support vectors (SVs’), making it unsuitable for applications involving large-scale streaming data. Limited-scale LSSVM, which allows efficient updating, seems to be a good solution to tackle this issue. In this paper, to train the limited-scale LSSVM dynamically, we present a budget online LSSVM (BOLSSVM) algorithm. Methodologically, by setting a fixed budget for SVs’, we are able to update the LSSVM model according to the updated SVs’ set dynamically without retraining from scratch. In particular, when a new small chunk of SVs’ substitute for the old ones, the proposed algorithm employs a low rank correction technology and the Sherman–Morrison–Woodbury formula to compute the inverse of saddle point matrix derived from the LSSVM’s Karush-Kuhn-Tucker (KKT) system, which, in turn, updates the LSSVM model efficiently. In this way, the proposed BOLSSVM algorithm is especially useful for online prediction tasks. Another merit of the proposed BOLSSVM is that it can be used for$k$-fold cross validation. Specifically, compared with batch-mode learning methods, the computational complexity of the proposed BOLSSVM method is significantly reduced from$\mathcal {O}(n^{4})$to$\mathcal {O}(n^{3})$for leave-one-out cross validation with$n$training samples. The experimental results of classification and regression on benchmark data sets and real-world applications show the validity and effectiveness of the proposed BOLSSVM algorithm.

Recent years have witnessed the prevalence of networked data in various domains. Among them, a large number of networks are not only topologically structured but also have a rich set of features on nodes. These node features are usually of high dimensionality with noisy, irrelevant and redundant information, which may impede the performance of other learning tasks. Feature selection is useful to alleviate these critical issues. Nonetheless, a vast majority of existing feature selection algorithms are predominantly designed in a static setting. In reality, real-world networks are naturally dynamic, characterized by both topology and content changes. It is desirable to capture these changes to find relevant features tightly hinged with network structure continuously, which is of fundamental importance for many applications such as disaster relief and viral marketing. In this paper, we study a novel problem of time-evolving feature selection for dynamic networks in an unsupervised scenario. Specifically, we propose a TeFS framework by leveraging the temporal evolution property of dynamic networks to update the feature selection results incrementally. Experimental results show the superiority of TeFS over the state-of-the-art batch-mode unsupervised feature selection algorithms.

SEQUEST is a database-searching engine, which calculates the correlation score between observed spectrum and theoretical spectrum deduced from protein sequences stored in a flat text file, even though it is not a relational and object-oriental repository. Nevertheless, the SEQUEST score functions fail to discriminate between true and false PSMs accurately. Some approaches, such as PeptideProphet and Percolator, have been proposed to address the task of distinguishing true and false PSMs. However, most of these methods employ time-consuming learning algorithms to validate peptide assignments [1] . In this paper, we propose a fast algorithm for validating peptide identification by incorporating heterogeneous information from SEQUEST scores and peptide digested knowledge. To automate the peptide identification process and incorporate additional information, we employ l2 multiple kernel learning (MKL) to implement the current peptide identification task. Results on experimental datasets indicate that compared with state-of-the-art methods, i.e., PeptideProphet and Percolator, our data fusing strategy has comparable performance but reduces the running time significantly.

Peptide sequence assignment is the central task in protein identification with MS/MS-based strategies. Sequence database searching routinely generate a large number of peptide spectrum matches (PSMs). Due to either the poor quality of the experimental MS/MS data or unexpected amino acid modifications, there are a large number of incorrect target PSMs. CRanker has shown its efficiency and accuracy in discrimination between correct and incorrect PSMs. However, it costs CRanker too much time on large PSM datasets as a built-in matlab optimization solver needs to be called for training the model. In this work, we exploit the bi-convex structure of the CRanker model and develop an alternate convex search (ACS) algorithm to reduce its total running time. At each iteration, ACS alternately solves one part of the problem when the other part of variables fixed. Compared with Matlab optimization tools, ACS is one order of magnitude faster on most datasets.

Black-box models play an important role in advancing the blast furnace modeling technologies for control purposes. To further enhance their practical applications, this paper is concerned with the transparency and comprehensibility of blast furnace black-box models. A fuzzy-based support vector machine (SVM) classification algorithm is proposed to perform the tasks of determining the controllable bound from the real data, of reducing feature from extensive candidate inputs, and of training the SVM model parameters. Based on these results, a fuzzy-based blast furnace SVM three-class classifier is constructed to serve for the classification problem according to the output lower than its controlled bound, within the controlled bound and higher than the controlled bound. Further, rule extraction is made to achieve the understandability of the constructed SVM classifier. Through two typical real blast furnace cases, the extracted rules can work well in classifying the hot metal silicon content into low, proper, and high range with high transparency, as well as encouraging agreements between the predicted values and the real ones. Moreover, there needs to be very little information on the blast furnace variables when implementing every rule in practice. The extracted rules provide a more explicit and direct indication for the blast furnace operators and, thus, may serve better for decision-making with blast furnace control.

This paper constructs the framework of the reproducing kernel Hilbert space for multiple kernel learning, which provides clear insights into the reason that multiple kernel support vector machines (SVM) outperform single kernel SVM. These results can serve as a fundamental guide to account for the superiority of multiple kernel to single kernel learning. Subsequently, the constructed multiple kernel learning algorithms are applied to model a nonlinear blast furnace system only based on its input-output signals. The experimental results not only confirm the superiority of multiple kernel learning algorithms, but also indicate that multiple kernel SVM is a kind of highly competitive data-driven modeling method for the blast furnace system and can provide reliable indication for blast furnace operators to take control actions.

The multidimensional blast furnace system is one of the most complex industrial systems and, as such, there are still many unsolved theoretical and experimental difficulties, such as silicon prediction and blast furnace automation. For this reason, this paper is concerned with developing data-driven models based on the Volterra series for this complex system. Three kinds of different low-order Volterra filters are designed to predict the hot metal silicon content collected from a pint-sized blast furnace, in which a sliding window technique is used to update the filter kernels timely. The predictive results indicate that the linear Volterra predictor can describe the evolvement of the studied silicon sequence effectively with the high percentage of hitting the target, very low root mean square error and satisfactory confidence level about the reliability of the future prediction. These advantages and the low computational complexity reveal that the sliding-window linear Volterra filter is full of potential for multidimensional blast furnace system. Also, the lack of the constructed Volterra models is analyzed and the possible direction of future investigation is pointed out.