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This study employed machine learning to generate hypotheses about the factors (and their combinations) that induce activities in green spaces in neighborhoods from the perspective of behavioral change. A cross-sectional study was conducted in March 2021 using an online survey in Osaka, Japan (n = 5108). We conducted (1) probabilistic latent semantic analysis (pLSA) to extract latent classes related to activities in green spaces and (2) classification tree analysis with the latent classes as the objective variables. As a result of clustering through pLSA, six latent classes were extracted for activities in green spaces. These classes indicated a gradation of behavioral change stages as follows: (1) difficult access, (2) precontemplation, (3) contemplation, (4) preparation, (5) action–maintenance, and (6) stability. Classification tree analysis indicated that different factors at different behavioral change stages promoted or inhibited activities in green spaces. "Difficult access" was more likely applicable when urban residents lived in neighborhoods where both the built environment and the social environment were undesirable. "Precontemplation" was more likely applicable where urban residents did not have positive perceptions of the effects of green space and social interactions with neighbors. "Contemplation" and "preparation" did not show any growth in the classification tree. "Action–maintenance" was more likely applicable when urban residents engaged in social activities in the neighborhoods. "Stability" was more likely applicable when urban residents had positive perceptions of the effects of green space and social interactions with neighbors. [ABSTRACT FROM AUTHOR]

Nowadays, technology has played a vital role in the advancement of the healthcare sector. Various healthcare datasets are available on the web in the form of patents, scientific papers, articles, textual feedback, chatlogs, abstracts of papers, medical reports, and social media posts. It is a tedious task for the stakeholders to find hidden crucial knowledge on the discussed topic from this content, which if utilized optimally can lead to the rapid development of the healthcare sector. Topic analysis concepts are very effective in extracting meaningful topics from the data. Here, frequently applied Topic modeling methods-Latent Semantic Analysis, Probabilistic Latent Semantic Analysis, Latent Dirichlet Allocation, Correlated Topics Model, and Nonnegative matrix factorization are surveyed along with their benefits and drawbacks. Insights on new innovative topic modeling techniques used in healthcare with their objective, opportunities, and challenges are provided, which can help the researchers for the enhancement of healthcare facilities. [ABSTRACT FROM AUTHOR]

Probabilistic Latent Semantic Analysis (PLSA) is a fundamental text analysis technique that models each word in a document as a sample from a mixture of topics. PLSA is the precursor of probabilistic topic models including Latent Dirichlet Allocation (LDA). PLSA, LDA and their numerous extensions have been successfully applied to many text mining and retrieval tasks. One important extension of LDA is supervised LDA (sLDA), which distinguishes itself from most topic models in that it is supervised. However, to the best of our knowledge, no prior work extends PLSA in a similar manner sLDA extends LDA by jointly modeling the contents and the responses of documents. In this paper, we propose supervised PLSA (sPLSA) which can efficiently infer latent topics and their factorized response values from the contents and the responses of documents. The major challenge lies in estimating a document's topic distribution which is a constrained probability that is dictated by both the content and the response of the document. To tackle this challenge, we introduce an auxiliary variable to transform the constrained optimization problem to an unconstrained optimization problem. This allows us to derive an efficient Expectation and Maximization (EM) algorithm for parameter estimation. Compared to sLDA, sPLSA converges much faster and requires less hyperparameter tuning, while performing similarly on topic modeling and better in response factorization. This makes sPLSA an appealing choice for latent response analysis such as ranking latent topics by their factorized response values. We apply the proposed sPLSA model to analyze the controversy of bills from the United States Congress. We demonstrate the effectiveness of our model by identifying contentious legislative issues. [ABSTRACT FROM AUTHOR]

This manuscript provides a comprehensive exploration of Probabilistic latent semantic analysis (PLSA), highlighting its strengths, drawbacks, and challenges. The PLSA, originally a tool for information retrieval, provides a probabilistic sense for a table of co-occurrences as a mixture of multinomial distributions spanned over a latent class variable and adjusted with the expectation–maximization algorithm. The distributional assumptions and the iterative nature lead to a rigid model, dividing enthusiasts and detractors. Those drawbacks have led to several reformulations: the extension of the method to normal data distributions and a non-parametric formulation obtained with the help of Non-negative matrix factorization (NMF) techniques. Furthermore, the combination of theoretical studies and programming techniques alleviates the computational problem, thus making the potential of the method explicit: its relation with the Singular value decomposition (SVD), which means that PLSA can be used to satisfactorily support other techniques, such as the construction of Fisher kernels, the probabilistic interpretation of Principal component analysis (PCA), Transfer learning (TL), and the training of neural networks, among others. We also present open questions as a practical and theoretical research window. [ABSTRACT FROM AUTHOR]

Exploring the symbolic semantic design path of industrial products is to make industrial products more compatible with the diverse emotional needs of consumers. In this paper, starting from the sentiment analysis model, the PLSA-FSVM sentiment analysis method is constructed using a probabilistic latent potential semantic analysis method and support vector machine based on the Fisher kernel. The method’s validity is verified for comparative experiments and sentiment word frequency analysis evaluation. From the comparison experiments, the ten-fold cross-average precision and recall of PLSA-FSVM were 89.18% and 88.35%, respectively, 4.15% and 2.59% higher than PLSA-SVM. From the sentiment word frequency analysis, the percentages of sentiment words such as atmosphere, practical, and worthy are 23.08%, 22.59%, and 24.72%, respectively. This shows that the PLSA-FSVM sentiment analysis method can effectively realize the sentiment analysis of industrial product evaluation, promote the symbolic semantic design to be more in line with consumers’ emotional needs, and then realize the symbolic design of industrial products to reach the meaning with shape and enjoy with meaning.

This manuscript provides a comprehensive exploration of Probabilistic latent semantic analysis (PLSA), highlighting its strengths, drawbacks, and challenges. The PLSA, originally a tool for information retrieval, provides a probabilistic sense for a table of co-occurrences as a mixture of multinomial distributions spanned over a latent class variable and adjusted with the expectation–maximization algorithm. The distributional assumptions and the iterative nature lead to a rigid model, dividing enthusiasts and detractors. Those drawbacks have led to several reformulations: the extension of the method to normal data distributions and a non-parametric formulation obtained with the help of Non-negative matrix factorization (NMF) techniques. Furthermore, the combination of theoretical studies and programming techniques alleviates the computational problem, thus making the potential of the method explicit: its relation with the Singular value decomposition (SVD), which means that PLSA can be used to satisfactorily support other techniques, such as the construction of Fisher kernels, the probabilistic interpretation of Principal component analysis (PCA), Transfer learning (TL), and the training of neural networks, among others. We also present open questions as a practical and theoretical research window.

A marketing policy called the ”Membership Stage System” is widely used in retail business. A membership stage provides benefits to customers such as shopping points when a customer’s annual cumulative purchase amount exceeds a certain threshold and the customer’s stage is raised a level. As a result, the company is not only able to promote the customer’s willingness to purchase, but it can also obtain the purchasing history data, thereby enabling high-quality customer analysis. The most fundamental analysis is to infer the difference of purchasing characteristics between member stages and to construct different clustering models for each member stage. However, when the clustering models are learned independently for each membership stage, it is not possible to compare the obtained clusters between membership stages. In this study, we propose a new analytical method and its learning algorithm to analyze differences in cluster distribution between membership stages. Through demonstrating the proposed model applied to an actual data set of purchasing history data on a membership stage system, the effectiveness of our proposal is clarified. [ABSTRACT FROM AUTHOR]

In recent years, it has become common to analyze purchase history data and take advantage of the effect on business policies. In this study, the authors focus on the case of a company that is introducing a membership stage system. Probabilistic latent semantic analysis (PLSA) is well-known as an analytical model for analysis of co-occurrence of variables in data. However, the relationship between customers and items for the customer purchase behavior of each stage based on PLSA has not shown good performance. The purchase behaviors may be slightly different between customer stages, and accordingly, the purchase behavior of customers in different stages should be represented by a similar but different model. In addition, the higher the membership stage, the fewer customers there are; therefore, it becomes difficult to accurately understand the features of the customers’ purchase behavior within high membership stages. In this study, the authors propose a learning algorithm that utilizes the estimated parameters of the behavior model based on the PLSA model at a lower-stage, to estimate the parameters of models at a higher-stage to which few people belong. Moreover, numerical simulation experiments are conducted and compared to actual purchase history data to confirm the performance of the proposed method. [ABSTRACT FROM AUTHOR]

Automatic image annotation plays a significant role in image understanding, retrieval, classification, and indexing. Today, it is becoming increasingly important in order to annotate large-scale social media images from content-sharing websites and social networks. These social images are usually annotated by user-provided low-quality tags. The topic model is considered as a promising method to describe these weak-labeling images by learning latent representations of training samples. The recent annotation methods based on topic models have two shortcomings. First, they are difficult to scale to a large-scale image dataset. Second, they can not be used to online image repository because of continuous addition of new images and new tags. In this paper, we propose a novel annotation method based on topic model, namely local learning-based probabilistic latent semantic analysis (LL-PLSA), to solve the above problems. The key idea is to train a weighted topic model for a given test image on its semantic neighborhood consisting of a fixed number of semantically and visually similar images. This method can scale to a large-scale image database, as training samples involved in modeling are a few nearest neighbors rather than the entire database. Moreover, this proposed topic model, online customized for the test image, naturally addresses the issue of continuous addition of new images and new tags in a database. Extensive experiments on three benchmark datasets demonstrate that the proposed method significantly outperforms the state-of-the-art especially in terms of overall metrics.

Urban system is shaped by the interactions between different regions and regions planned by the government, then reshaped by human activities and residents’ needs. Understanding the changes of regional structure and dynamics of city function based on the residents’ movement demand are important to evaluate and adjust the planning and management of urban services and internal structures. This paper constructed a probabilistic factor model on the basis of probabilistic latent semantic analysis and tensor decomposition, for purpose of understanding the higher order interactive population mobility and its impact on urban structure changes. First, a four-dimensional tensor of time (T) × week (W) × origin (O) × destination (D) was constructed to identify the day-to-day activities in three time modes and weekly regularity of weekday/weekend pattern. Then we reclassified the urban regions based on the space clustering formed by the space factor matrix and core tensor. Finally, we further analysed the space–time interaction on different time scales to deduce the actual function and connection strength of each region. Our research shows that the application of individual-based spatial–temporal data in human mobility and space–time interaction study can help to analyse urban spatial structure and understand the actual regional function from a new perspective.

The Probabilistic Latent Semantic Analysis has been related with the Singular Value Decomposition. Several problems occur when this comparative is done. Data class restrictions and the existence of several local optima mask the relation, being a formal analogy without any real significance. Moreover, the computational difficulty in terms of time and memory limits the technique applicability. In this work, we use the Nonnegative Matrix Factorization with the Kullback–Leibler divergence to prove, when the number of model components is enough and a limit condition is reached, that the Singular Value Decomposition and the Probabilistic Latent Semantic Analysis empirical distributions are arbitrary close. Under such conditions, the Nonnegative Matrix Factorization and the Probabilistic Latent Semantic Analysis equality is obtained. With this result, the Singular Value Decomposition of every nonnegative entries matrix converges to the general case Probabilistic Latent Semantic Analysis results and constitutes the unique probabilistic image. Moreover, a faster algorithm for the Probabilistic Latent Semantic Analysis is provided.

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Abstract The lack of trilinear structure is known to limit the application of chemometric techniques on the total synchronous fluorescence spectroscopy (TSFS) data sets. To overcome this limitation, the present work successfully proposes application of Akaike information criterion (AIC) assisted probabilistic latent semantic analysis (pLSA) algorithm on TSFS data sets. The present work also discusses various practical and theoretical aspects that need to be considered while applying AIC assisted pLSA algorithm on TSFS data sets. Graphical abstract Image 1 Highlights • Total synchronous fluorescence spectroscopy (TSFS) data lack the trilinear structure. • Probabilistic Latent Semantic Analysis (pLSA) algorithm is successfully applied on non-trilinear TSFS data sets. • Akaike information criterion (AIC) technique allows automatic selection of the optimum pLSA model. • Resolved TSFS components by pLSA are chemically meaningful and accurate. [ABSTRACT FROM AUTHOR]

In order to effectively solve the problem of new items and obviously improve the accuracy of the recommended results, we proposed a collaborative recommendation algorithm based on improved probabilistic latent semantic model in this paper, which introduces popularity factor into probabilistic latent semantic analysis to derive probabilistic matrix factorization model. The core idea is to integrate the semantic knowledge into the recommendation process to overcome the shortcomings of the traditional recommendation algorithm. We introduced popularity factor to form a quintuple vector so as to understand user preference, and can integrate the probabilistic matrix factorization to solve the problem of data sparsity on basis of Probabilistic Latent Semantic Analysis; then the probabilistic matrix factorization model is adopted to construct the weighted similarity function to compute the recommendation result. Experimental study on real-world data-sets demonstrates that our proposed method can outperform three state-of-the art methods in recommendation accuracy. [ABSTRACT FROM AUTHOR]

Urban system is shaped by the interactions between different regions and regions planned by the government, then reshaped by human activities and residents' needs. Understanding the changes of regional structure and dynamics of city function based on the residents' movement demand are important to evaluate and adjust the planning and management of urban services and internal structures. This paper constructed a probabilistic factor model on the basis of probabilistic latent semantic analysis and tensor decomposition, for purpose of understanding the higher order interactive population mobility and its impact on urban structure changes. First, a four-dimensional tensor of time (T) × week (W) × origin (O) × destination (D) was constructed to identify the day-to-day activities in three time modes and weekly regularity of weekday/weekend pattern. Then we reclassified the urban regions based on the space clustering formed by the space factor matrix and core tensor. Finally, we further analysed the space-time interaction on different time scales to deduce the actual function and connection strength of each region. Our research shows that the application of individual-based spatial-temporal data in human mobility and space-time interaction study can help to analyse urban spatial structure and understand the actual regional function from a new perspective. [ABSTRACT FROM AUTHOR]