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Citation - WoS: 102
Citation - Scopus: 113
A 1.6-Mm, Metal Tube Ultrasonic Motor
(Ieee-inst Electrical Electronics Engineers inc, 2003) Cagatay, S; Koc, B; Uchino, K
A miniaturized metal tube ultrasonic motor, the dimensions of which are 1.6 mm in diameter and 6 rum in length, was developed. Two flattened surfaces with 90-degrees were ground on the outer surface of the stator. Two PZT-based piezoelectric ceramics were bonded onto these flat surfaces. The asymmetrical surface of the stator developed the split of the two degenerated orthogonal bending modes, resulting in a wobble motion. The working frequency of the 1.6-mm motor with 6 mm in length was 130 kHz. A torque of 0.5 mNm was reached at a maximum power of 45 mW with a speed of 45 rad/sec. The maximum efficiency was 16%.
Citation - WoS: 30
Citation - Scopus: 34
Discrete Time Shock Models in a Markovian Environment
(Ieee-inst Electrical Electronics Engineers inc, 2016) Eryilmaz, Serkan
This paper deals with two different shock models in a Markovian environment. We study a system from a reliability point of view under these two shock models. According to the first model, the system fails if the cumulative shock magnitude exceeds a critical level, while in the second model the failure occurs when the cumulative effect of the shocks in consecutive periods is above a critical level. The shock occurrences over discrete time periods are assumed to be Markovian. We obtain expressions for the failure time distributions of the system under the two model. Illustrative computational results are presented for the survival probabilities and mean time to failure values of the system.
Citation - WoS: 3
Citation - Scopus: 3
Analysis of the Junction Properties of C/Gase_{0.5< Back-To Schottky-Type Photodetectors}
(Ieee-inst Electrical Electronics Engineers inc, 2015) Khanfar, Hazem K.; Qasrawi, Atef F.; Gasanly, Nizami M.
In this paper, a C/GaSe0.5S0.5/C metal-semiconductor-metal photodetector is suggested and described. The device is explored by means of current-voltage and capacitance-voltage (C-V) characteristics under different photoexcitation intensities. It was observed that the design of the back-to-back Schottky device has reduced the dark current of the normal Ag/GaSe0.5S0.5/C Schottky diode by 13 times and increased the photosensitivity from 3.8 to similar to 2.1x10(3). The device exhibited a barrier height of 0.842 eV in the dark. The barrier height is reduced via photoexcitation. In addition, the C/GaSe0.5S0.5/C device exhibited an ON/OFF switching property from low injection OFF to high injection ON at specific biasing voltages. This voltage decreased with the increasing illumination intensity. On the other hand, the C-V characteristics of the device, which was recorded for an ac input signal with 100 MHz at different levels of photoexcitation shifted up when the intensity of light was increased. When the same measurement was repeated at signal frequency of 1.6 GHz, the C-V characteristics reflected a different level of capacitance response. These features of C/GaSe0.5S0.5/C photodetectors nominate the device to be used as multipurpose optical switches being suitable to store different levels of electromagnetic energy at microwave frequencies.
Citation - WoS: 9
Citation - Scopus: 9
Mixture Representations for Three-State Systems With Three-State Components
(Ieee-inst Electrical Electronics Engineers inc, 2015) Eryilmaz, Serkan
This paper is concerned with dynamic reliability modeling of three-state systems consisting of three-state s-independent components. The components and the systems are assumed to be in three states: perfect functioning, partial performance, and complete failure. Survival functions of such systems are studied in different state subsets. It is shown that the survival function of a three-state system with a general structure can be represented as a mixture of the survival functions of the three-state k-out-of-n:G systems. The results are illustrated for the three-state consecutive-k-out-of-n:G systems whose components degrade according to a Markov process.
Citation - WoS: 14
Citation - Scopus: 16
Joint Reliability Importance in Coherent Systems With Exchangeable Dependent Components
(Ieee-inst Electrical Electronics Engineers inc, 2016) Eryilmaz, Serkan; Oruc, Ozlem Ege; Oger, Volkan
In this paper, a general formula for computing the joint reliability importance of two components is obtained for a binary coherent system that consists of exchangeable dependent components. Using the new formula, the joint reliability importance can be easily calculated if the path sets of the system are known. As a special case, an expression for the joint reliability importance of two components is also obtained for a system consisting of independent and identical components. Illustrative numerical results are presented to compare the joint reliability importance of two components in the bridge system for the two cases when the components are exchangeable dependent and when the components are independent and identical.
Citation - WoS: 33
Citation - Scopus: 41
Visual and Auditory Data Fusion for Energy-Efficient and Improved Object Recognition in Wireless Multimedia Sensor Networks
(Ieee-inst Electrical Electronics Engineers inc, 2019) Koyuncu, Murat; Yazici, Adnan; Civelek, Muhsin; Cosar, Ahmet; Sert, Mustafa
Automatic threat classification without human intervention is a popular research topic in wireless multimedia sensor networks (WMSNs) especially within the context of surveillance applications. This paper explores the effect of fusing audio-visual multimedia and scalar data collected by the sensor nodes in a WMSN for the purpose of energy-efficient and accurate object detection and classification. In order to do that, we implemented a wireless multimedia sensor node with video and audio capturing and processing capabilities in addition to traditional/ordinary scalar sensors. The multimedia sensors are kept in sleep mode in order to save energy until they are activated by the scalar sensors which are always active. The object recognition results obtained from video and audio applications are fused to increase the object recognition performance of the sensor node. Final results are forwarded to the sink in text format, and this greatly reduces the size of data transmitted in network. Performance test results of the implemented prototype system show that the fusing audio data with visual data improves automatic object recognition capability of a sensor node significantly. Since auditory data requires less processing power compared to visual data, the overhead of processing the auditory data is not high, and it helps to extend network lifetime of WMSNs.
Citation - WoS: 6
Citation - Scopus: 8
Hybrid Electrooptic and Piezoelectric Laser Beam Steering in Two Dimensions
(Ieee-inst Electrical Electronics Engineers inc, 2005) Scrymgeour, DA; Koc, B; Tian, LL; Gentzel, MW; Uchino, K; Gopalan, V
With modern optical technology, there is a great demand for devices capable of steering a laser beam. at high speed. A hybrid electrooptical scanner and an electromechanical scanner capable of two-dimensional (2-D) laser beam scanning Eire demonstrated. This device can scan a laser beam in 2-D. A V scanning angle in the horizontal axis at 50 Hz using electrooptic scanning and a 5.23 degrees scanning angle in vertical axis at 25.6 kHz using piezoelectric scanning are shown.
Citation - WoS: 80
Citation - Scopus: 103
Sensors in Assisted Living a Survey of Signal and Image Processing Methods
(Ieee-inst Electrical Electronics Engineers inc, 2016) Erden, Fatih; Velipasalar, Senem; Alkar, Ali Ziya; Cetin, A. Enis
[No Abstract Available]
Citation - WoS: 63
Citation - Scopus: 98
Improved Routh-Pade Approximants: a Computer-Aided Approach
(Ieee-inst Electrical Electronics Engineers inc, 2004) Singh, V; Chandra, D; Kar, H
A geometric programming based computer-aided method to derive a reduced order (rth-order) approximant for a given (stable) SISO linear continuous-time system is presented. In this method, stability and the first r time moments/Markov parameters are preserved as well as the errors between a set of subsequent time moments/Markov parameters of the system and those of the model are minimized.
Citation - WoS: 12
Citation - Scopus: 17
Limit and Application Range of the Slope-Diffraction Method for Wireless Communications
(Ieee-inst Electrical Electronics Engineers inc, 2003) Kara, A; Bertoni, HL; Yazgan, E
Limitations on the use of the uniform theory of diffraction (UTD) slope-diffraction. method for propagation past knife edges are investigated. The settled field that is diffracted past rows of buildings, as computed by numerical integration, has the characteristics of amplitude and phase variation with a scale length that is large compared to wavelength and,has small amplitude near the edges. Using this field, it is shown that the error in the UTD slope-diffraction method for diffraction past a final screen is connected with the Fresnel width, as compared to the scale length of the settled

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