درخت حوزه‌های تخصصی

VANET (Vehicular Ad-hoc Network) is a developing technology, which is a combination of cellular technology, ad-hoc network & wireless LAN to improve the safety of vehicle as well as driver. VANET communication can be of two types, first one is broadcast and second one is unicast. Either communication may be broadcast or unicast both are sensitive to different types ofassaults, for example message forgery, (DOS) denial of service, Sybil assault, Greyhole, Blackhole & Wormhole assault. In this paper machine learning method is used to detect the wormhole assault in VANET’s multi-hop communication. We have created a scenario of VANET by using AODV routing protocol on NS-3.24.1 simulator, which utilizes the overall mobility traces generated by the simulator SUMO-0.32.0 to model the wormhole assault. The simulation is performed by using NS-3.24.1 simulator, and the statistics created by flow monitor are collected. The collected data is pre-processed and the k-NN & Random Forest algorithms are applied on this data, to make the model such type so that it can memorize the wormhole attack. The novelty of this research work is that with the help of proposed detection & prevention technique, vehicular ad-hoc network can be made free from wormhole assault by using ML approach. The performance of proposed machine learning models is compared with existing work. In this way it is clear that our proposed approach by using ML is powerful tool by which the wormhole assaults can be detected in VANETs. A scheme based on packet lease and cryptographic techniques is used to prevent the wormhole attack in VANET

Predicting financial markets has always been one of the most challenging issues, attracting the attention of many investors and researchers. In this regard, deep learning methods have been used a lot recently. Due to the desired results, such networks are always in development and progress. One of the networks that is being implemented in various fields is capsule network. The first time the classification capsule network was introduced, it was able to attract a lot of attention with its success on MNIST data 1 . In such networks, as in the other ones, the parameters are obtained by minimizing a loss function. In this paper, we first change the classification capsule network to a regression capsule network by modifying the last layer of the network. Then we use different information measures such as Kullnack-Leibler, Lin-Wang and Triangular information measures as a loss function, and compare their results with wellknown models including Artificial Neural Network (ANN), Convolutional Network (CNN) and Long Short-Term Memory (LSTM) as well as common used loss functions such as Mean Square Error (MSE) and Mean Absolute Percentage Error (MAPE). Using appropriate accuracy metrics, it is shown that the capsule network using triangular information measure is well able to predict the price of bitcoin for the medium and long term period including 10, 90 and 180 days.

In the academic context, social networking sites (SNSs) have reshaped the way university students connect and communicate with each other, and the way they learn, thus influencing their identities and dimensions. This paper aims to investigate the impacts of SNSs use by students on their academic performance at the University of Taiz. A survey questionnaire was conducted to a total sample of 357 undergraduate students via personal administration and by an online platform to gather the initial information on their use of SNSs and the influence on their academic performance. The hypotheses of this study were studied and tested using descriptive statistics, regression model, T-test, and analysis of variance (ANOVA). The findings of H1 indicate that the impact of the use of SNSs on students’ academic performance was statistically significant Interaction with the teacher (II) Collaboration with coworkers (CC) Engagement (EN) and learning a cooperating (LC). Meanwhile, the results of H2 indicate no significant differences between the mean averages of the respondents’ answers for (purposes, the impact of the use of SNSs, and academic performance) due to gender, and age, respectively. Thus, using SNS as a learning tool has a great potential to improve students’ academic performance because it allows students to be more connected. Overall findings of this study indicate that the use of SNSs impact undergraduate students by factors are studied on academic Performance to some extent and suggested future strategies to enhance students’ awareness to manage their time, multitasking skills, and study activities to enhance their academic performance and achievements.