551 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)

    Internal quality assessment of tomato fruits using image color analysis

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    Nondestructive optical methods based on image analysis have been used for determining quality of tomato fruit. It is rapid and requires less sample preparation. A samples of fresh tomatoes were picked at different maturity stages, and determining chromaticity values (L*,a*,b*,a*/b*,h˚and ΔE) by image analysis and colorimeter. Total soluble solids (TSS), were measured by refractometer, lycopene extracting and expressed as mg/kg fresh tomato (FW). Results indicated that, during ripening both L*, b*, h˚, and ΔE tendency to decline, opposite tendency was determined with a*, a*/b* ratio, TSS and lycopene content. Chromaticity values have an important impact in internal quality parameters. Where, avg. of TSS, entire class and lycopene content had a positive linear correlation with a*/b* ratio. Contrary correlation was determined between avg. of TSS, entire class and both h˚ and ΔE. Meanwhile, h˚ and ΔE, had a negative logarithmic correlation with lycopene content. On the other hand, there were positive correlation between chromaticity values performed by image analysis technology and colorimeter. Where, on determining avg. of TSS, entire class, and lycopene content, correlations were linear with a*/b* ratio, and logarithmic with ΔE. Meanwhile, h˚ had alogarithmic correlation on determining avg. of TSS, entire class, and exponential correlation on determining lycopene content

    Compact V-Shaped MIMO Antenna For LTE And 5G Communications

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    A new small V-shaped MIMO antenna with dimensions of the antenna 21 × 24 × 0.8 mm within the bands of (4.4-4.9) and (5.15-5.925) GHz was designed, and the fabrication and measurement outcomes derived from the use of the MIMO prototype revealed that the fractal MIMO antenna. The small and simple fractal antenna demonstrated high isolation of less than -18.5 dB and envelope correlation coefficient less than 0.05. These attributes are suitable for mobile, which is being introduced into Japanese markets

    SMS Security by Elliptic Curve and Chaotic Encryption Algorithms

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    Short message services (SMS) represent one of the components of the global communications network and are one of the important developments in communication technologies and communications technology. SMS messages without a password are stored in the SMS server. For the purpose of review and dispute resolution. The security of SMS content cannot be protected because it is transmitted in plain text and is accessible to network operators and employees. Therefore, the end-to-end key is based on encryption and decryption technology can provide SMS security. The security protocols used for SMS security on contemporary mobile devices were examined in this study. SMS security system encryption time affects how well mobile devices work. This shows that security technologies take longer to generate keys and encrypt keys as the key size increases. Due to the limited processing power of mobile devices, large-scale algorithms such as DES, AES, RC4, and Blowfish are not suitable for SMS encryption. SMS may be encrypted using the elliptic curve technique because it provides great security with a smaller key on devices with limited resources, such as mobile phones. And chaotic theory, encryption is simple, fast and secure data encryption. As a result, a combination of elliptic curve algorithm and chaotic encryption algorithm is proposed to achieve a high level of security. In this paper, several tests have been done to compare the algorithms in terms of throughput, power consumption, SMS size, encoding time, and decoding time. The results indicate that the proposed method is better than the comparison method.

    Compact V-Shaped MIMO Antenna For LTE And 5G Applications

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    A compact sierpinski MIMO antenna was designed in the bands of 4.4 - 4.9 GHz and 5.15 - 5.925 GHz.The proposed dimension of the antenna were 21 × 24 × 0.8 mm, and was fabricated with inexpensive FR4 substrate with a thickness of 0.8 mm, a dielectric constant of 4.3, and 0.035-mm thick copper lining. The fabrication and measurement outcomes derived from the MIMO prototypes revealed that the proposed MIMO antennas are better in terms of size, isolation and the ECC. These attributes are suitable for LTE and 5G smartphone applications, which are being introduced into Chinese and Japanese markets

    Compact Crescent Slot MIMO Antenna With Quad Bands And High Isolation For LTE And 5G Communications

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    A new small crescent MIMO antenna with dimensions of the antenna 31 × 31 × 0.8 mm within the bands of (2.5-2.7, 3.6-4.2, 4.4-4.5, and 5.15-5.6) GHz was designed, and the fabrication and measurement outcomes derived from the use of the MIMO prototype revealed that the crescent MIMO antenna. The small and simple crescent antenna demonstrated high isolation of less than -13.5, -10.5, -15.5 and -29.5dB and envelope correlation coefficient less than 0.01, 0.0024, 0.0008 and 0.0011 respectively. These attributes are suitable for LTE and 5G communications, which is being introduced into China and Japanese markets

    Compact Mimo Slots Antenna Design With Different Bands And High Isolation For 5G Smartphone Applications

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    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)

    Pattern reconfigurable dielectric resonator antenna using capacitor loading for internet of things applications

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    This research study presents a cube dielectric resonator antenna (DRA) with four different radiation patterns for internet of things (IoT) applications. The various radiation patterns are determined by the grounded capacitor loading to reduce interference. The DRA is constructed of ceramic material with a dielectric constant of 30 and is fed via a coaxial probe located in the antenna’s center. Capacitors are used to load the four parasitic microstrip feed lines. Each pattern of radiation is adjustable by adjusting the capacitors loading on the feed line. The proposed antenna works at 3.5 GHz with -10 narrow impedance bandwidth of 74 MHz

    The Role of 3D CT Imaging in the Accurate Diagnosis of Lung Function in Coronavirus Patients

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    Early grading of coronavirus disease 2019 (COVID-19), as well as ventilator support machines, are prime ways to help the world fight this virus and reduce the mortality rate. To reduce the burden on physicians, we developed an automatic Computer-Aided Diagnostic (CAD) system to grade COVID-19 from Computed Tomography (CT) images. This system segments the lung region from chest CT scans using an unsupervised approach based on an appearance model, followed by 3D rotation invariant Markov–Gibbs Random Field (MGRF)-based morphological constraints. This system analyzes the segmented lung and generates precise, analytical imaging markers by estimating the MGRF-based analytical potentials. Three Gibbs energy markers were extracted from each CT scan by tuning the MGRF parameters on each lesion separately. The latter were healthy/mild, moderate, and severe lesions. To represent these markers more reliably, a Cumulative Distribution Function (CDF) was generated, then statistical markers were extracted from it, namely, 10th through 90th CDF percentiles with 10% increments. Subsequently, the three extracted markers were combined together and fed into a backpropagation neural network to make the diagnosis. The developed system was assessed on 76 COVID-19-infected patients using two metrics, namely, accuracy and Kappa. In this paper, the proposed system was trained and tested by three approaches. In the first approach, the MGRF model was trained and tested on the lungs. This approach achieved 95.83% accuracy and 93.39% kappa. In the second approach, we trained the MGRF model on the lesions and tested it on the lungs. This approach achieved 91.67% accuracy and 86.67% kappa. Finally, we trained and tested the MGRF model on lesions. It achieved 100% accuracy and 100% kappa. The results reported in this paper show the ability of the developed system to accurately grade COVID-19 lesions compared to other machine learning classifiers, such as k-Nearest Neighbor (KNN), decision tree, naïve Bayes, and random forest

    Loss of balancing selection in the βS globin locus

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    <p>Abstract</p> <p>Background</p> <p>Probably the best example of the rise and maintenance of balancing selection as an evolutionary trend is the role of S-haemoglobin (HbS - rs334) in protecting from malaria. Yet, the dynamics of such a process remains poorly understood, particularly in relation to different malaria transmission rates and the genetic background of the affected populations.</p> <p>Methods</p> <p>We investigated the association of haemoglobin HbS in protection from clinical episodes of malaria in two populations/villages where malaria is endemic, but mostly presenting in mild clinical forms. Five-hundred and forty-six individuals comprising 65 and 82 families from the Hausa and Massalit villages respectively were genotyped for HbS. Allele and genotype frequencies as well as departure from Hardy-Weinberg Equilibrium were estimated from four-hundred and seventy independent genotypes across different age groups. Age-group frequencies were used to calculate the coefficient-of-fitness and to simulate the expected frequencies in future generations.</p> <p>Results</p> <p>Genotype frequencies were within Hardy-Weinberg expectations in Hausa and Massalit in the total sample set but not within the different age groups. There was a trend for a decrease of the HbS allele frequency in Hausa and an increase of frequency in Massalit. Although the HbS allele was able to confer significant protection from the clinical episodes of malaria in the two populations, as suggested by the odds ratios, the overall relative fitness of the HbS allele seems to have declined in Hausa.</p> <p>Conclusions</p> <p>Such loss of balancing selection could be due to a combined effect of preponderance of non-clinical malaria in Hausa, and the deleterious effect of the homozygous HbS under circumstances of endogamy.</p
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