Browsing by Author "Öğrenci, Arif Selçuk"
Now showing items 1-9 of 9
-
Anomaly Detection in Walking Trajectory
Analysis of the walking trajectory and the detection of anomalies in this trajectory, provide important benefits in the fields of health and security. In this work, two methods to detect anomalies in trajectories, are compared. Firstly, an unsupervised method is used where the conformance among trajectories are taken into consideration. Trajectories that deviate from others are qualified as anomalies. Secondly, the points in the trajectories are considered as a time series. Artifical neural networks ...
-
Channel Estimation for Visible Light Communications Using Neural Networks
Authors:Yeşilkaya, Anıl; Karatalay, Onur; Öğrenci, Arif Selçuk; Panayırcı, Erdal
Publisher and Date:(IEEE, 2016)Visible light communications (VLC) is an emerging field in technology and research. Estimating the channel taps is a major requirement for designing reliable communication systems. Due to the nonlinear characteristics of the VLC channel those parameters cannot be derived easily. They can be calculated by means of software simulation. In this work, a novel methodology is proposed for the prediction of channel parameters using neural networks. Measurements conducted in a controlled experimental setup ...
-
Ekonomi haberlerinin BIST100 ve hisse senetlerinin fiyat değişimleri üzerindeki etkisinin incelenmesi
Bu çalışmada ilk olarak, ekonomi haberlerinin belli bir kaynaktan toplanması, Bag-of-Words (ön tanımlı kelime grupları) yöntemi ile pozitif ve negatif olarak ayrıştırılması için bir yazılım geliştirilmiştir. Daha sonra bu ayrıştırma işleminin başarı oranı ele alınmıştır. İstanbul Borsası endeksindeki hareketlerin pozitif-negatif haberlerden ne kadar etkilendiği ve ileri yönelik tahmin yapılıp yapılamayacağı incelenerek bu gözlemlere dayalı bir portföy yönetim stratejisi önerilmiştir. Literatürde ...
-
A Hybrid Deep Learning Framework for Unsupervised Anomaly Detection in Multivariate Spatio-Temporal Data
Multivariate time-series data with a contextual spatial attribute have extensive use for finding anomalous patterns in a wide variety of application domains such as earth science, hurricane tracking, fraud, and disease outbreak detection. In most settings, spatial context is often expressed in terms of ZIP code or region coordinates such as latitude and longitude. However, traditional anomaly detection techniques cannot handle more than one contextual attribute in a unified way. In this paper, a ...
-
A hybrid deep learning framework for unsupervised anomaly detection in multivariate spatio-temporal data
Authors:Karadayı, Yıldız; Aydın, Mehmet Nafiz; Öğrenci, Arif Selçuk
Publisher and Date:(MDPI AG, 2020)Multivariate time-series data with a contextual spatial attribute have extensive use for finding anomalous patterns in a wide variety of application domains such as earth science, hurricane tracking, fraud, and disease outbreak detection. In most settings, spatial context is often expressed in terms of ZIP code or region coordinates such as latitude and longitude. However, traditional anomaly detection techniques cannot handle more than one contextual attribute in a unified way. In this paper, a ...
-
Mathematical models for phase transitions in biogels
Authors:Bilge, Ayşe Hümeyra; Öğrenci, Arif Selçuk; Pekcan, Önder
Publisher and Date:(World Scientific Publ Co Pte Ltd, 2019)It has been shown that reversible and irreversible phase transitions of biogels can be represented by epidemic models. The irreversible chemical sol-gel transitions are modeled by the Susceptible-Exposed-Infected-Removed (SEIR) or Susceptible-Infected-Removed (SIR) epidemic systems whereas reversible physical gels are modeled by a modification of the Susceptible-Infected-Susceptible (SIS) system. Measured sol-gel and gel-sol transition data have been fitted to the solutions of the epidemic models, ...
-
Secure loyalty cards in mobile
In this study, it is intended to develop a loyalty application by utilizing NFC technology, used by an increasing number of devices today, and QRCode, which has begun to be used in many sectors. It is aimed to collect all discount cards and mark cards taken from each company and safely use them. Barcode reading is performed for devices with an Android software and NFC support while card reading is performed devices without NFC by using QRCode. When the application is run; the barcode is scanned ...
-
Sickle Cell Anemia Detection
Authors:Albayrak, Batuhan; Darıcı, Muazzez Buket; Kiracı, Furkan; Öğrenci, Arif Selçuk; Özmen, Atilla; Ertez, Kerem
Publisher and Date:(Institute of Electrical and Electronics Engineers Inc., 2018)Anemia is a common name given to falls in oxygen transport capacity due to some of the functional disadvantages of red blood cells. Pathology Laboratorians put the tissue on the microscope glass and try to diagnose Anemia disease. Processes have been taken for a long time and it has been caused to distract. Therefore it has been caused to misdiagnose the Laboratorian. This work shortens the diagnostic period of the disease and to minimizes error probability of this diagnosis by extracting healthy ...
-
Smart chatbot
Chatbot is an abbreviation of chat and robot. Nowadays, we can see ChatBot as the primitive state of artificial intelligence. Chatbot is an algorithm based on software that we can do some special work, chat and talk for fun. The emergence and implementation of the ChatBot idea begins with a theory of Alan Turing. The Turing test includes a user, a computer and a person which responding to this user. The computer and people answer the questions the user asks. If the user can not figure out which ...