Gazi University Dspace
Not a member yet
    26981 research outputs found

    Olive Leaf (Olea europaea L. folium): Potential Effects on Glycemia and Lipidemia

    No full text
    Background: Olive tree (Olea europaea, Oleaceae) leaves have been widely used in traditional herbal medicine to prevent and treat various diseases especially in Mediterranean countries. They contain several potentially bioactive compounds that may have hypoglycemic and hypolipidemic properties. Summary: The literature has recently been attempting to define the relationship between olive leaf (Olea europaea L. folium) polyphenols and a number of health problems. Oleuropein, the basic phenolic compound of olive leaf and its extract, is responsible for the characteristic bitter taste and unique aroma of olive fruits. Furthermore, it is shown that oleuropein and its hydrolyzed products have many beneficial effects on human health because of its antioxidant characters. A number of studies report that olive leaf has potentially positive effects on the parameters related to diabetes and cardiovascular diseases by various mechanisms. Besides, toxicity studies suggest that olive leaf is generally safe even at high doses. Key messages: Although current results obtained until today seem promising, the studies in this subject are usually on cell culture and animal trials. Moreover, mostly the extract forms of olive leaves are used in the studies. More randomized controlled human clinical trials with extensive toxicity studies are needed to evaluate potential health effects and safety. (c) 2020 S. Karger AG, Base

    A Review of Control Methods on Suppression of 2 < italic >\& x03C9;</italic > Ripple for Single-Phase Quasi-Z-Source Inverter

    No full text
    One of the disadvantages of the charging systems and voltage regulation systems in alternative energy systems is that when the direct current (DC)/alternative current (AC) or AC/DC conversion is made from the energy source, the energy flow at frequency between the direct current side and the alternative current side causes ripples in the DC, inductors, and capacitors. The ripples that occur in frequency increase the harmonic distortion and reduce the efficiency in the photovoltaic energy system. For addressing this problem, different control methods are evaluated in this paper for the elimination of ripples that occur at frequency, both on the perspective of DC control side and AC control side with a thorough comparative analysis with existing results in the literature. In the present study, the model of Single-Phase Quasi-Z Source (QZS) inverter and closed-loop control methods of the inverter are examined and compared with pulse width modulation (PWM) methods. In addition, the control methods are used to eliminate the ripples at frequency in the use of inverters, and the advantages and disadvantages of these methods are presented

    Detecting DDoS Attacks in Software-Defined Networks Through Feature Selection Methods and Machine Learning Models

    No full text
    Software Defined Networking (SDN) offers several advantages such as manageability, scaling, and improved performance. However, SDN involves specific security problems, especially if its controller is defenseless against Distributed Denial of Service (DDoS) attacks. The process and communication capacity of the controller is overloaded when DDoS attacks occur against the SDN controller. Consequently, as a result of the unnecessary flow produced by the controller for the attack packets, the capacity of the switch flow table becomes full, leading the network performance to decline to a critical threshold. In this study, DDoS attacks in SDN were detected using machine learning-based models. First, specific features were obtained from SDN for the dataset in normal conditions and under DDoS attack traffic. Then, a new dataset was created using feature selection methods on the existing dataset. Feature selection methods were preferred to simplify the models, facilitate their interpretation, and provide a shorter training time. Both datasets, created with and without feature selection methods, were trained and tested with Support Vector Machine (SVM), Naive Bayes (NB), Artificial Neural Network (ANN), and K-Nearest Neighbors (KNN) classification models. The test results showed that the use of the wrapper feature selection with a KNN classifier achieved the highest accuracy rate (98.3\%) in DDoS attack detection. The results suggest that machine learning and feature selection algorithms can achieve better results in the detection of DDoS attacks in SDN with promising reductions in processing loads and times

    0

    full texts

    26,981

    metadata records
    Updated in last 30 days.
    Gazi University Dspace
    Access Repository Dashboard
    Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇