No abstract

Association rules are a fundamental class of patterns that exist in data. The key strength of association rule mining is its completeness. It finds all associations in the data that satisfy the user specified minimum support and minimum confidence constraints. This strength, however, comes with a major drawback. It often produces a huge number of associations. This ~ is particularly true for data sets whose attributes are highly correlated. The huge number of associations makes it very difficult, if not impossible, for a human user to analyze in order to identify those interesting/useful ones. In this paper, we propose a novel technique to overcome this problem. The technique first prunes the discovered associations to remove those insignificant associations, and then finds a special subset of the unpruned associations to form a summary of the discovered associations.We call this subset of associations the direction setting (DS) rules as they set the directions that are followed by the rest of the associations. Using this summary, the user can focus on the essential aspects (or relationships) of the domain and selectively view the relevant details. The approach is effective because experiment results show that the set of DS rules is typically very small. They can be analyzed manually by a human user. The proposed technique has also been applied successfully to a number of real-life applications.

Abstract-Online reviews provide valuable information about products and services to consumers. However, spammers are joining the community trying to mislead readers by writing fake reviews. Previous attempts for spammer detection used reviewers' behaviors, text similarity, linguistics features and rating patterns. Those studies are able to identify certain types of spammers, e.g., those who post many similar reviews about one target entity. However, in reality, there are other kinds of spammers who can manipulate their behaviors to act just like genuine reviewers, and thus cannot be detected by the available techniques. In this paper, we propose a novel concept of a heterogeneous review graph to capture the relationships among reviewers, reviews and stores that the reviewers have reviewed. We explore how interactions between nodes in this graph can reveal the cause of spam and propose an iterative model to identify suspicious reviewers. This is the first time such intricate relationships have been identified for review spam detection. We also develop an effective computation method to quantify the trustiness of reviewers, the honesty of reviews, and the reliability of stores. Different from existing approaches, we don't use review text information. Our model is thus complementary to existing approaches and able to find more difficult and subtle spamming activities, which are agreed upon by human judges after they evaluate our results. 1

No abstract

A nano-Fe 3 O 4 -CoO x catalyst was prepared via a simple wet impregnation method. The nano-Fe 3 O 4 -CoO x catalyst showed good catalytic performance for the conversion of 5-hydroxymethylfurfural into 2, 5-furandicarboxylic acid (FDCA) with t-BuOOH as the oxidant. Several important reaction parameters were explored, with the highest FDCA yield of 68.6% obtained from HMF after 15 h at a reaction temperature of 80 o C. One-pot conversion of fructose into FDCA was also successful via two steps. Catalytic conversion of fructose over Fe 3 O 4 @SiO 2 -SO 3 H yielded 93.1% HMF, which was oxidized in-situ into FDCA with a yield of 59.8%. Furthermore, recycling of nano-Fe 3 O 4 -CoO x was accomplished with the help of a magnetic field. Nano-Fe 3 O 4 -CoO x showed high stability in the reaction process. The use of non-precious metals and no requirement of a base additive made this method much more economical and environmental-friendly.

No abstract

ABSTRATClustering aims to find the intrinsic structure of data by organizing data objects into similarity groups or clusters. It is often called unsupervised learning as no class labels denoting an a priori partition of the objects are given. This is in contrast with supervised learning (e.g., classification) for which the data objects are already labeled with known classes. Past research in clustering has produced many algorithms. However, these algorithms have some major shortcomings. In this paper, we propose a novel clustering technique, which is based on a supervised learning technique called decision tree construction. The new technique is able to overcome many of these shortcomings. The key idea is to use a decision tree to partition the data space into cluster and empty (sparse) regions at different levels of details. The technique is able to find "natural" clusters in large high dimensional spaces efficiently. It is suitable for clustering in the full dimensional space as well as in subspaces. It also provides comprehensible descriptions of clusters. Experiment results on both synthetic data and real-life data show that the technique is effective and also scales well for large high dimensional datasets.

Deep learning has achieved great success in hyperspectral image classification. However, when processing new hyperspectral images, the existing deep learning models must be retrained from scratch with sufficient samples, which is inefficient and undesirable in practical tasks. This paper aims to explore how to accurately classify new hyperspectral images with only a few labeled samples, i.e., the hyperspectral images few-shot classification. Specifically, we design a new deep classification model based on relational network and train it with the idea of meta-learning. Firstly, the feature learning module and the relation learning module of the model can make full use of the spatial–spectral information in hyperspectral images and carry out relation learning by comparing the similarity between samples. Secondly, the task-based learning strategy can enable the model to continuously enhance its ability to learn how to learn with a large number of tasks randomly generated from different data sets. Benefitting from the above two points, the proposed method has excellent generalization ability and can obtain satisfactory classification results with only a few labeled samples. In order to verify the performance of the proposed method, experiments were carried out on three public data sets. The results indicate that the proposed method can achieve better classification results than the traditional semisupervised support vector machine and semisupervised deep learning models.