1,117 research outputs found

    Compact MIMO Slots Antenna Design with Different Bands and High Isolation for 5G Smartphone Applications

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    في هذه الورقة ، تم استخدام عنصرين من هوائي متعدد المدخلات متعدد المخرجات (MIMO)  لدراسة النطاقات  ((3.1-3.55) - (3.7-4.2) - (3.4-4.7) - ( 3.4-3.8) - (3.6-4.2)) جيجا هيرتز لتطبيقات الجيل الخامس(5G) والمستخدمة في الهواتف الذكية التي سيتم طرحها في أسواق الولايات المتحدة وكوريا وأوروبا والصين واليابان.  يبلغ حجم الهوائي المقترح  26 × 46 × 0.8 ملم مكعب، مع هيكل مناسب وصغير الحجم اضافة الى ذلك أظهر الهوائي المقترح عزلة وكفاءة عاليتين، كذلك اظهر مستوى منخفض لمعامل الارتباط المغلف (ECC) وعودة الخسارة، هذه المواصفات تتناسب تماما تطبيقات الجيل الخامس (5G). وقد تم تصنيع الهوائي المقترح من مادة FR4  الغيرمكلفة بمستوى سماكة 0.8 ملم، وشدة فقدان مقدارها 0.035 وثابت عازل قدره 4.3 ، اظهرت نتائج المحاكاة لهوائيات MIMO المقترحة التي تغطي النطاقات الخمسة المختلفة مستوى عزل عالي لكل منها حوالي 14 ديسيبل و 12 ديسيبل و 21.5 ديسيبل و 19 ديسيبل و 20 ديسيبل تحت عرض النطاق الترددي العائق -10 ديسيبل. ومن خلال التصنيع والقياس للنموذج الاولي  لهوائي ( MIMO) الذي يغطي النطاق (3.4-3.8) المستخدم  في كل من أوروبا والصين، وجد أن الهوائي المقترح قد حقق أداء أفضل من حيث الكفاءة والعزلة ومعامل الارتباط المغلف(ECC). In this paper, two elements of the multi-input multi-output (MIMO) antenna had been used to study the five (3.1-3.55GHz and 3.7-4.2GHz), (3.4-4.7 GHz), (3.4-3.8GHz) and (3.6-4.2GHz) 5G bands of smartphone applications that is to be introduced to the respective US, Korea, (Europe and China) and Japan markets. With a proposed dimension of 26 × 46 × 0.8 mm3, the medium-structured and small-sized MIMO antenna was not only found to have demonstrated a high degree of isolation and efficiency, it had also exhibited a lower level of envelope correlation coefficient and return loss, which are well-suited for the 5G bands application. From the fabrication of an inexpensive FR4 substrate with a 0.8 mm thickness level, a loss tangent of 0.035 and a dielectric constant of 4.3, the proposed MIMO antennas that had been simulated under the five different band coverage were discovered to have demonstrated a respective isolation level of about 14dB, 12dB, 21.5dB, 19dB and 20dB under a -10dB impendence bandwidth. In the measurement and fabrication outcomes that were derived from the use of the prototype MIMO in the (3.4-3.8) band of the Europe and Chinese markets, the proposed MIMO was thus found to have produced a better performance in terms of efficiency, isolation, and envelope correlation coefficient (ECC)

    Machine Learning and Signal Processing Design for Edge Acoustic Applications

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    A comprehensive comparison between design for testability techniques for total dose testing of flash-based FPGAs

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    Radiation sources exist in different kinds of environments where electronic devices often operate. Correct device operation is usually affected negatively by radiation. The radiation resultant effect manifests in several forms depending on the operating environment of the device like total ionizing dose effect (TID), or single event effects (SEEs) such as single event upset (SEU), single event gate rupture (SEGR), and single event latch up (SEL). CMOS circuits and Floating gate MOS circuits suffer from an increase in the delay and the leakage current due to TID effect. This may damage the proper operation of the integrated circuit. Exhaustive testing is needed for devices operating in harsh conditions like space and military applications to ensure correct operations in the worst circumstances. The use of worst case test vectors (WCTVs) for testing is strongly recommended by MIL-STD-883, method 1019, which is the standard describing the procedure for testing electronic devices under radiation. However, the difficulty of generating these test vectors hinders their use in radiation testing. Testing digital circuits in the industry is usually done nowadays using design for testability (DFT) techniques as they are very mature and can be relied on. DFT techniques include, but not limited to, ad-hoc technique, built-in self test (BIST), muxed D scan, clocked scan and enhanced scan. DFT is usually used with automatic test patterns generation (ATPG) software to generate test vectors to test application specific integrated circuits (ASICs), especially with sequential circuits, against faults like stuck at faults and path delay faults. Despite all these recommendations for DFT, radiation testing has not benefited from this reliable technology yet. Also, with the big variation in the DFT techniques, choosing the right technique is the bottleneck to achieve the best results for TID testing. In this thesis, a comprehensive comparison between different DFT techniques for TID testing of flash-based FPGAs is made to help designers choose the best suitable DFT technique depending on their application. The comparison includes muxed D scan technique, clocked scan technique and enhanced scan technique. The comparison is done using ISCAS-89 benchmarks circuits. Points of comparisons include FPGA resources utilization, difficulty of designs bring-up, added delay by DFT logic and robust testable paths in each technique

    Machine Learning and Signal Processing Design for Edge Acoustic Applications

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    Assessing EFL Learners’ Consecutive Interpreting Skills

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    Interpreting is taught to senior EFL learners in Saudi Faculties of Arts. Since it is a branch with a vast number of skills, the present study seeks to evaluate EFL learners’ interpreting skills. Forty graduate-level majors at Uqlat Asoqour Faculty of Arts, Qassim University were chosen randomly to sit for an interpreting test. A consecutive interpreting skills rubric was used to assess twelve interpreting skills over six points scale. Results of the statistical analysis showed variances among the subjects’ interpreting skills, with a need to tackle some of interpreting skills intensively in the translation and interpreting courses presented to EFL students in Faculties of Arts

    Yasak kalktıkça Yılmaz Güney imzası taşıyan ne varsa piyasaya sürülüyor:Çirkin Kral kazandırıyor

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    Taha Toros Arşivi, Dosya No: 162-Yılmaz Güneyİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

    Fast learning algorithm for Gabor transformation, A

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    Includes bibliographical references.An adaptive learning approach for the computation of the coefficients of the generalized nonorthogonal 2-D Gabor transform representation is introduced in this correspondence. The algorithm uses a recursive least squares (RLS) type algorithm. The aim is to achieve minimum mean squared error for the reconstructed image from the set of the Gabor coefficients. The proposed RLS learning offers better accuracy and faster convergence behavior when compared with the least mean squares (LMS)-based algorithms. Applications of this scheme in image data reduction are also demonstrated

    Confidence Intervals for Parallel Systems with Covariates

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    Exact confidence intervals for regression models with censored data are often not tractable, and hence approximate intervals are derived. The most common method of obtaining these approximate intervals is based on the asymptotic normal distribution of the maximum likelihood estimator. These intervals are easy to compute and they are used in most computer statistical packages. However, these intervals have some limitations. When the sample size is small or even moderate they tend to be anticonservative and have asymmetric upper and lower tail probabilities. An alternative method based on the asymptotics of the maximum likelihood estimator is to construct intervals from the inverted likelihood ratio tests. The performance of these intervals is investigated for the regression models based on parallel systems with covariates, and with randomly right censored data for finite samples. The simulation results show that the intervals based on the inverted likelihood ratio test have better performance. They have coverage probability that is close to the nominal one, and have nearly symmetric upper and lowel tail probabilities

    Solving Modal Equations of Motion with Initial Conditions Using MSC/NASTRAN DMAP

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    By utilizing MSC/NASTRAN DMAP (Direct Matrix Abstraction Program) in an existing NASA Lewis Research Center coupled loads methodology, solving modal equations of motion with initial conditions is possible using either coupled (Newmark-Beta) or uncoupled (exact mode superposition) integration available within module TRD1. Both the coupled and newly developed exact mode superposition methods have been used to perform transient analyses of various space systems. However, experience has shown that in most cases, significant time savings are realized when the equations of motion are integrated using the uncoupled solver instead of the coupled solver. Through the results of a real-world engineering analysis, advantages of using the exact mode superposition methodology are illustrated
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