Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
Browse
17 results
Search Results
Article Citation - WoS: 7Citation - Scopus: 8Compact Wideband Tapered-Fed Printed Bow-Tie Antenna With Rectangular Edge Extension(John Wiley and Sons Inc., 2019) Bozdağ, Göksenin; Seçmen, MustafaIn this article, a wideband printed bow-tie antenna is designed entire band of GPS (L5), PCS, IMT-2000, Bluetooth, Wi-Fi, WiMAX bands, and the most of frequency range of UWB. Apart from the traditional designs, the proposed antenna includes tapered printed line with a feeding point patch and triangular bows with rectangular edge extensions, which makes the antenna more compact. The antenna realized at the frequency band of 1.49-9.5 GHz (more than 6.3:1 ratio bandwidth) has the dimensions of 122mmx56mm (0.61(0)x0.28(0)). According to measurement results, the realized gain varies between almost 1 and 6.5 dBi with 4.44dBi average, which are in good agreement with simulation results. Radiation patterns at the lower frequencies of operating band show dipole like radiation pattern with higher cross-pol discrimination levels while they degrade at the higher frequencies due to increase in gain.Article Citation - WoS: 16Citation - Scopus: 16Learning Control of Robot Manipulators in Task Space(John Wiley and Sons Inc., 2018) Doğan, Kadriye Merve; Tatlıcıoğlu, Enver; Zergeroğlu, Erkan; Çetin, KamilTwo important properties of industrial tasks performed by robot manipulators, namely, periodicity (i.e., repetitive nature) of the task and the need for the task to be performed by the end-effector, motivated this work. Not being able to utilize the robot manipulator dynamics due to uncertainties complicated the control design. In a seemingly novel departure from the existing works in the literature, the tracking problem is formulated in the task space and the control input torque is aimed to decrease the task space tracking error directly without making use of inverse kinematics at the position level. A repetitive learning controller is designed which “learns” the overall uncertainties in the robot manipulator dynamics. The stability of the closed-loop system and asymptotic end-effector tracking of a periodic desired trajectory are guaranteed via Lyapunov based analysis methods. Experiments performed on an in-house developed robot manipulator are presented to illustrate the performance and viability of the proposed controller.Article Citation - WoS: 59Citation - Scopus: 57Cmos Enabled Microfluidic Systems for Healthcare Based Applications(John Wiley and Sons Inc., 2018) Hussian, Muhammad M.; Khan, Sherjeel M.; Gümüş, Abdurrahman; Nassar, Joanna M.With the increased global population, it is more important than ever to expand accessibility to affordable personalized healthcare. In this context, a seamless integration of microfluidic technology for bioanalysis and drug delivery and complementary metal oxide semiconductor (CMOS) technology enabled data-management circuitry is critical. Therefore, here, the fundamentals, integration aspects, and applications of CMOS-enabled microfluidic systems for affordable personalized healthcare systems are presented. Critical components, like sensors, actuators, and their fabrication and packaging, are discussed and reviewed in detail. With the emergence of the Internet-of-Things and the upcoming Internet-of-Everything for a people–process–data–device connected world, now is the time to take CMOS-enabled microfluidics technology to as many people as possible. There is enormous potential for microfluidic technologies in affordable healthcare for everyone, and CMOS technology will play a major role in making that happen.Other Citation - WoS: 2Citation - Scopus: 1Erratum To: Multi-Band Cpw Fed Mimo Antenna for Bluetooth, Wlan, and Wimax Applications(John Wiley and Sons Inc., 2017) Deste, İrem; Bozdağ, Göksenin; Kuştepeli, AlpIn the above-mentioned article, which appeared in Microwave and Optical Technology Letters, Volume 58#9, DOI 30001, the captions for Figure 1 and Figure 4 were published incorrectly. The corrections are shown below: Figure 1 Element antenna (a) Geometry (b) Fabricated (a = 12.5 mm, b = m = v = o = 0.5 mm, c = 4 mm, d = n = 15 mm, e = h = 3 mm, f = 14 mm, g = 16 mm, i = 7 mm, k = 1.5 mm, l = 12 mm, p = 1.25 mm, r = 1.64 mm, s = 1.7 mm, t = 1.94 mm, u = 11.1 mm, w = 0.3 mm). [Color figure can be viewed at wileyonlinelibrary.com] Figure 4 Fabricated MIMO antenna (d1 = d3 = 7 mm, d2 = 10 mm, d4 = 12 mm). [Color figure can be viewed at wileyonlinelibrary.com] In addition, Figure 6 was published with an error. The corrected figure is shown below: The publisher regrets any confusion caused by these errors. (Figure presented.).Article Citation - WoS: 11Citation - Scopus: 11Design and Development of an Educational Desktop Robot R3d(John Wiley and Sons Inc., 2017) Şahin, Osman Nuri; Uzunoğlu, Emre; Tatlıcıoğlu, Enver; Dede, Mehmet İsmet CanRobotic desktop devices have been used for academic purposes for a variety of investigation and development studies. Desktop devices for academic/educational purposes have been highly anticipated especially in the fields of haptics, teleoperation systems, and control studies. This paper's motivation is to present the steps of designing, manufacturing, and implementing of Educational Desktop Robot R3D to be used for haptics, teleoperation, and redundancy control studies. The design, manufacturing details, kinematic, and dynamic model of the robot are described in the manuscript. Additionally, a case study is carried out for end effector control in task space is given and the results are shared.Other Citation - WoS: 1Erratum: Wideband Planar Monopole Antennas for Gps/Wlan and X-Band Applications (microwave and Optical Technology Letters 58:2)(John Wiley and Sons Inc., 2016) Bozdağ, Göksenin; Kuştepeli, AlpArticle Citation - WoS: 5Citation - Scopus: 9Wideband Planar Monopole Antennas for Gps/Wlan and X-Band Applications(John Wiley and Sons Inc., 2016) Bozdağ, Göksenin; Kuştepeli, AlpIn this article, two printed planar monopole antennas (PPMA) are presented. In the design of the first PPMA, the structure is divided into sections and they are optimized in the sense of bottom to up strategy. Tapered transitions and inset feed are employed to increase the bandwidth. The antenna operates between 2.37 GHz and 12 GHz with VSWR<2 and an average peak realized gain of 4.95 dB. Therefore, it is suitable for WLAN, WiMAX, UWB, and X-Band applications. The second PPMA is designed by implementing slots on the previous one to include GPS. The resulting antenna operates in the 1.38-1.60 GHz and 2.33-13.74 GHz bands with VSWR<2. As a result, it also includes GPS in addition to the previous bands. The peak realized gain in GPS is 0.47 dB at 1.575 GHz and the average peak realized gain is 4.41 dB for the 2.33-13.74 GHz band. The group delay performances of the proposed PPMAs are also examined and the maximum group delay deviations of the first and the second PPMAs are observed as 1 ns and 1.33 ns, respectively.Article Citation - WoS: 13Citation - Scopus: 18Multi-Band Cpw Fed Mimo Antenna for Bluetooth, Wlan, and Wimax Applications(John Wiley and Sons Inc., 2016) Desde, İrem; Bozdağ, Göksenin; Kuştepeli, AlpIn this letter, multi-band coplanar waveguide (CPW) fed multiple-input-multiple-output (MIMO) antenna is presented for Bluetooth, WLAN and WiMAX applications. The elements of MIMO antenna are identical CPW-fed printed monopole antennas whose bandwidth performances are improved by employing inverse U and meander line slots. In the design of the antennas, a low-cost FR4 substrate is used and the size of the element antennas are optimized as 35 mm x 30 mm. According to the measurements, S11 is below −10 dB in 2.38 GHz – 2.52 GHz and 3.19 GHz – 6.44 GHz bands with 0.2 dB and 2.9 dB average peak realized gains, respectively. The element antennas are placed orthogonally and fed independently to obtain MIMO structure whose size is optimized as 42 mm x 62 mm. The performance of MIMO antenna is also examined in terms of diversity parameters such as envelope correlation coefficient and apparent diversity gain, which are lower than 0.02 and higher than 9.9 in the operating bands, respectively.Article Citation - Scopus: 1On Stream Selection for Interference Alignment With Limited Feedback in Heterogeneous Networks(John Wiley and Sons Inc., 2016) Aycan, Esra; Özbek, Berna; Le Ruyet, DidierThis paper presents a stream selection based interference alignment approach with imperfect channel state information for heterogeneous networks. The proposed solution constructs stream sequences by selecting only the strongest stream of each user where the first stream of the constructed stream sequences is associated to a pico user. While selecting the streams, the channel matrices of the unselected streams are projected orthogonally to the virtual transmit and receive channels of the selected stream in order to align the interference in the null space of these virtual channels. In addition, the influence of imperfect channel state information on the proposed algorithm is analysed. A bit allocation scheme is given by deriving an upper bound on the rate loss because of quantisation. The simulation results are carried out by considering various scenarios with different locations of pico cells at the cell edge regions of the macro cell. The performance results show that the proposed algorithm with the imperfect channel state information achieves higher performance than the existing algorithms.Article Citation - WoS: 6Citation - Scopus: 9Goodput and Throughput Comparison of Single-Hop and Multi-Hop Routing for Ieee 802.11 Dcf-Based Wireless Networks Under Hidden Terminal Existence(John Wiley and Sons Inc., 2016) Aydoğdu, Canan; Karaşan, EzhanWe investigate how multi-hop routing affects the goodput and throughput performances of IEEE 802.11 distributed coordination function-based wireless networks compared with direct transmission (single hopping), when medium access control dynamics such as carrier sensing, collisions, retransmissions, and exponential backoff are taken into account under hidden terminal presence. We propose a semi-Markov chain-based goodput and throughput model for IEEE 802.11-based wireless networks, which works accurately with both multi-hopping and single hopping for different network topologies and over a large range of traffic loads. Results show that, under light traffic, there is little benefit of parallel transmissions and both single-hop and multi-hop routing achieve the same end-to-end goodput. Under moderate traffic, concurrent transmissions are favorable as multi-hopping improves the goodput up to 730% with respect to single hopping for dense networks. At heavy traffic, multi-hopping becomes unstable because of increased packet collisions and network congestion, and single-hopping achieves higher network layer goodput compared with multi-hop routing. As for the link layer throughput is concerned, multi-hopping increases throughput 75 times for large networks, whereas single hopping may become advantageous for small networks. The results point out that the end-to-end goodput can be improved by adaptively switching between single hopping and multi-hopping according to the traffic load and topology.