156 results
Search Results
Now showing 1 - 10 of 156
Conference Object Design, Analysis and Manufacturing of Dielectric Rod Added Conical Rom Antennas(Ieee, 2016) Avcioglu, Esra; Özaslan, Alper; Caliskan, FatmaIn this study, ANSYS HFSS (High Frequency Structural Simulator) software had been used. By using this software, dielectric rod added conical horn antennas with various shapes and dimensions had been designed and analyzed. 5 (five) distinct antennas designed and their gains and return losses had been observed to evaluate the effects of the changes. From the results of these comparisons, the proper antenna type was selected and it was manufactured.Conference Object Citation - WoS: 3Citation - Scopus: 11Towards Modeling Patterns for Embedded Software Industry: Feedback From the Field(Ieee, 2018) Akdur, Deniz; Demirors, Onur; Say, BilgeThe analysis, design, implementation and testing of software for embedded systems are not trivial. Software modeling is a commonly used approach in the embedded software industry to manage complexity of these phases. The modeling approaches vary since the characteristics of modeling such as its purpose, the medium type used, the lifecycle phase used, differ among systems and industrial sectors. Our previous research identified and defined the modeling approach patterns in embedded software development projects based on quantitative data. In this paper, to validate and improve the pre-investigated pattern set, we present a series of semi-structured interviews over eight months with 53 embedded software professionals across a variety of target industrial sectors and roles. With the help of these interviews, the different modeling approach patterns in embedded software development were better understood and the hidden patterns not evident in the previous study were identified along with a documentation of personalized modeling experiences.Conference Object An Rfid Based Location Finding and Tracking With Guidance(Ieee, 2008) Oktem, Rusen; Aydin, Elif Uray; Cagiltay, Nergiz ErcilThis paper tackles an RFID based location finding and tracking system. The system is an integral part of a navigation aid being developed for guiding visually disabled people in a store. The aid is composed of a portable hardware interface unit, a standalone RFID unit, and a central processing unit. The units interact via wireless communication to locate the position of the user in a known indoor environment and tracking his/her movement. An active RFID tag helps to estimate the location of a user and the user is guided to follow a route accordingly, via a tactile compass. The system uses RF signal strengths and is based on Bayes Decision Theory. Initial simulation results with the system prove promising for location finding and tracking, especially when the tracked person is guided by a system.Conference Object Optimization of modeling parameters of of a direct dimethyl ether fuel cell (DDMEFC)(Ieee, 2019) Alpaydin, Guvenc Umur; Colpan, C. Ozgur; Devrim, YilserDirect alcohol fuel cells are one of the suitable candidates for sustainable power generation in portable applications. Among the different alcohol types that can be used in these fuel cells, DME, which is almost non-toxic at room temperature and easy to liquefy, and has a molecular structure similar to methanol, is one of the suitable options. For this reason, many studies have been carried out to develop direct dimethyl ether fuel cell (DDMEFC). Mathematical modeling studies also play an important role in the development of DDMEFC since they enable the understanding of the performance of the fuel cells more thoroughly. In this study, a model has been developed by using the principles of conservation chemical species and electrochemistry. A modeling study was performed using MATLAB. The values of some modeling parameters were estimated using the genetic algorithm optimization technique.Conference Object An Investigation About Process Matchmaking Performances of Unstructured and Decentralized Digital Environments(Ieee, 2007) Cakir, Bugra; Kilic, HurevrenEfficient matchmaking is an important problem in unstructured and decentralized digital environments. We report the results of simulations of these environments and provide measurements of match performance focusing on unstructured and decentralized environments. In the study, different environment models including P2P (Hypergrid, Gnutella with/without ultrapeer); small-world (Watts-Strogatz); heavy-tailed and random versions of Autonomous System Waxman model showing power-law distribution property; random and 2D-Grid are considered. The flooding mechanism enabling process encounters for match purposes is uninformed Breadth-First-Search. Simulations show that the matchmaking performance of random environment outperforms the others for almost all different problems and time-to-live settings. On the other hand, the total cost of small world environment model is the highest for almost all setups.Conference Object Density-Aware Outage in Clustered Ad Hoc Networks(Ieee, 2018) Eroglu, Alperen; Onur, Ertan; Turan, MehmetDensity of ad hoc networks may vary in time and space because of mobile stations, sleep scheduling or failure of nodes. Resources such as spectrum will be wasted if the network is not density-aware and -adaptive. Towards this aim, distributed and robust network density estimators are required. In this paper, we propose a novel cluster density estimator in random ad hoc networks by employing distance matrix. Monte-Carlo simulation results validate the proposed estimator. The accuracy of the estimator is impressive even under a high amount of distance measurement errors. We also propose a network outage model and a transmit power adaption technique that are density-aware. The results indicate the necessity of the density-aware solutions for making network performance better from capacity, coverage and energy conservation viewpoints.Conference Object Citation - WoS: 2New Wavelet-Based Features for the Recognition of Jittered and Stagger Pri Modulation Types(Ieee, 2015) Gencol, Kenan; Kara, Ali; At, NurayIn dense electronic warfare environments, numerous emitters can be active simultaneously and an interleaved stream of pulses in natural time of arrival order is received by the Electronic Support Measures (ESM) receiver. It is the task of the ESM system to de-interleave this mixed pulse sequence and thus to identify the surrounding threatening emitters. In this processing, pulse repetition interval (PRI) modulation recognition has a significant role due to the fact that it can reveal the hidden patterns inside pulse repetition intervals and thus help identify the emission source and its functional purpose. In this paper, we propose new wavelet-based features for the recognition of jittered and stagger PRI modulation types. The recognition of these types are heavily based on histogram features. Experimental results show that the proposed feature set have very high recognition rates and outperform histogram based methods.Conference Object Citation - WoS: 1An Industry Sponsored Undergraduate Research (ur) Experience: Preliminary Study on Fulfillment of Program Outcomes and Industry Requirements(Ieee, 2014) Kapusuz, Kamil Yavuz; Kara, AliThis study presents educational results of an industry sponsored undergraduate research (UR) project. The aim of the study is to show how such project works contribute to students in acquiring qualifications or skills necessary by the industry, and abilities regarding with program outcomes of accreditation organisations. The study is based on quantitative (surveys) and qualitative (self descriptions) data collected from senior students who worked in 9 months UR project sponsored by a company in Radio frequency (RF) and Communications domain. The preliminary results showed that an industry sponsored undergraduate research project may serve to both short term (industry requirements) and longer term (program outcomes) expectations in undergraduate curriculum of engineering departments.Conference Object Citation - WoS: 1THE USE OF CUMULANTS FOR VOICED-UNVOICED SEGMENTS IDENTIFICATION IN SPEECH SIGNALS(Ieee, 2014) Uslu, Baran; Tora, HakanIn this study, voiced-unvoiced classification performance of Turkish sounds using skewness and kurtosis is examined. The analyses show that higher order cumulants can be employed as a feature in voiced-unvoiced classification that is vital in speech processing applications. Furthermore, it has been shown that cumulants are also useful for identifying voiced and unvoiced segments in noisy speech signals.Conference Object Citation - Scopus: 1Biletini Devret: a Secure Mobile App for Ticket Sales(Ieee, 2021) Ak, Firat; Ozkan, Veli Batuhan; Gonder, Gokhan; Sumeroglu, Ersun; Eryilmaz, MeltemIt has been known that smartphones are the first thing that comes to mind when technology is mentioned. Almost every person has a smartphone, and they are used for social media, shopping, trade, and more. In the past, phones were just used for calculating something, or text messaging each other. However, nowadays, as mentioned above, they are used for complicated applications or works. Therefore, users need security for their private information. The Biletini Devret application in this study keeps users' private information secure with the help of Google Cloud Platforms and this application has two-factor verification to be more secure and to prevent unauthorized users. In particular, the Biletini Devret application has a Face Recognition System which has the most reliable authentication system all in the world.
