Tumor detection and isolation in magnetic resonance imaging (MRI) is a significant consideration, but when done manually by people, it is very time consuming and may not be accurate. Also, the appearance of the tumor tissue varies from patient to patient, and there are similarities between the tumor and the natural tissue of the brain. In this paper, we have tried to provide an automated method for diagnosing and displaying brain tumors in MRI images. Images of patients with glioblastoma were used after applying pre-processing and removing areas that have no useful information (such as eyes, scalp, etc.). We used a bounding box algorithm, to create a projection for to determining the initial range of the tumor in the next step, an artificial bee colony algorithm, to determine an initial point of the tumor area and then the Grow cut algorithm for, the exact boundary of the tumor area. Our method is automatic and extensively independent of the operator. comparison between results of 12 patients in our method with other similar methods indicate a high accuracy of the proposed method (about 98%) in comparison s.

Automatic topic detection seems unavoidable in social media analysis due to big text data which their users generate. Clustering-based methods are one of the most important and up-to-date categories in topic detection. The goal of this research is to have a wide study on this category. Therefore, this paper aims to study the main components of clustering-based-topic-detection, which are embedding methods, distance metrics, and clustering algorithms. Transfer learning and consequently pretrained language models and word embeddings have been considered in recent years. Regarding the importance of embedding methods, the efficiency of five new embedding methods, from earlier to recent ones, are compared in this paper. To conduct our study, two commonly used distance metrics, in addition to five important clustering algorithms in the field of topic detection, are implemented by the authors. As COVID-19 has turned into a hot trending topic on social networks in recent years, a dataset including one-month tweets collected with COVID-19-related hashtags is used for this study. More than 7500 experiments are performed to determine tunable parameters. Then all combinations of embedding methods, distance metrics and clustering algorithms (50 combinations) are evaluated using Silhouette metric. Results show that T5 strongly outperforms other embedding methods, cosine distance is weakly better than other distance metrics, and DBSCAN is superior to other clustering algorithms.

A teacher of Computer Science and Mathematics has two options: use precious classroom time in routine operations and boring formulas, thus killing the interest of students and hampering their intellectual development, or challenge their curiosity by formulating interesting and stimulating questions giving them a taste for independent thinking. The teacher need only provide the building blocks and let students themselves form more complex structures, providing them timely hints when needed. In this paper we demonstrate how a very simple procedure can be used, with minor modifications, as a building block to solve a variety of seemingly unrelated problems in the field of graph algorithms.

Domain generation algorithms (DGAs) are used in Botnets as rendezvous points to their command and control (C&C) servers, and can continuously provide a large number of domains which can evade detection by traditional methods such as Blacklist. Internet security vendors often use blacklists to detect Botnets and malwares, but the DGA can continuously update the domain to evade blacklist detection. In this paper, first, using features engineering; the three types of structural, statistical and linguistic features are extracted for the detection of DGAs, and then a new dataset is produced by using a dataset with normal DGAs and two datasets with malicious DGAs. Using supervised machine learning algorithms, the classification of DGAs has been performed and the results have been compared to determine a DGA detection model with a higher accuracy and a lower error rate. The results obtained in this paper show that the random forest algorithm offers accuracy rate, detection rate and receiver operating characteristic (ROC) equal to 89. 32%, 91. 67% and 0. 889, respectively. Also, compared to the results of the other investigated algorithms, the random forest algorithm presents a lower false positive rate (FPR) equal to 0. 373.