Rotated Rectangular Slots And Mirrored Inversed Cantor-sets On Ultrawideband Antipodal Vivaldi Antenna

Variants of antipodal Vivaldi antenna (AVA) design suitable for access point working on 0.5 – 6.0 GHz are proposed in this paper. The novel designs were produced by employing three novel techniques to conventional AVA: (i) rotated-slot pattern to shift down the frequency cutoff and enhancing bandwidth, (ii) curve design to miniaturize rotated-slot-inserted antipodal Vivaldi, and (iii) fractal-director (Cantor set) to increase the gain of antipodal Vivaldi. Using FR4 (relative permittivity of 4.4) with an overall dimension of 300 mm x 143 mm x 1.6 mm the antenna designs are able to work at a frequency of 0.472 GHz to higher than 6 GHz with a maximum gain of 11.9 dBi

Sistem Tracking Panel Surya untuk Pengoptimalan Daya Menggunakan Metode Kendali Logika Fuzzy

Salah satu jenis energi alternatif yang berkembang pesat dan banyak digunakan adalah energi matahari yang digunakan sebagai pembangkit listrik, dalam bentuk panel surya. Dalam rangka mengoptimalkan penggunaan panel surya tersebut, diperlukan sebuah sistem pengendali yang dapat mengontrol posisi panel surya agar selalu mengikuti arah dan posisi dari matahari secara otomatis. Sistem yang digunakan untuk pengaturan tersebut dinamakan sistem tracking matahari dengan dua derajat kebebasan. Sistem ini bekerja menggunakan Perubahan daya yang terbaca oleh panel surya. Kelebihan dari sistem ini dapat mengikuti posisi matahari. Dalam sistem ini digunakan perbandingan daya yang terbaca oleh sistem dan mencari yang paling optimal diantara daya tersebut. Berdasarkan perbedaan daya yang diterima, Kendali Logika Fuzzy akan menggerakkan motor servo untuk melakukan aksi kendali terhadap posisi panel surya supaya selalu tegak lurus terhadap posisi matahari. Perbandingan respon unjuk kerja antara sistem yang tanpa menggunakan kontroler fuzzy yaitu tegangan =15,40 V, arus = 0,46 A, dan daya = 7.17 W , sedangkan untuk sistem yang menggunakan kontroler fuzzy 2 DOF (Degree Of Freedom) menghasilkan tegangan = 15,54 V, arus = 0,51 A, dan daya = 7.94 W. Sistem yang dibuat sudah mengikuti matahari untuk mencapai daya yang maksimal

Development of Bio-impedance Analyzer (BIA) for Body Fat Calculation

Common weight scales cannot assess body composition or determine fat mass and fat-fress mass that make up the body weight. This research propose bio-impedance analysis (BIA) tool capable to body composition assessment. This tool uses four electrodes, two of which are used for 50 kHz sine wave current flow to the body and the rest are used to measure the voltage produced by the body for impedance analysis. Parameters such as height, weight, age, and gender are provided individually. These parameters together with impedance measurements are then in the process to produce a body fat percentage. The experimental result shows impressive repeatability for successive measurements (stdev ≤ 0.25% fat mass). Moreover, result on the hand to hand node scheme reveals average absolute difference of total subjects between two analyzer tools of 0.48% (fat mass) with maximum absolute discrepancy of 1.22% (fat mass). On the other hand, the relative error normalized to Omron's HBF-306 as comparison tool reveals less than 2% relative error. As a result, the system performance offers good evaluation tool for fat mass in the body

How Can We Identify Hijacked Journals?

By developing research and academic centers, the number of performed research articles has also increased. On the other hand, publishing the results of these articles in scientific journals shall also grow. In the meantime, researchers are trying to publish the findings of their research in journals which have been approved by one or more International indices so that such findings can be seen. In order to enhance the academic standards of Universities, proper journal choice will be of interest to researchers, especially those that are indexed in websites such as Thomson Reuters. However, certain forgery frauds researchers by launching fake Web sites that have been named by academic journal titles. In this paper, we introduce an approach to identify this type of journals that will be applicable by researchers in various academic disciplines

Fusion Iris and Periocular Recognitions in Non-Cooperative Environment

The performance of iris recognition in non-cooperative environment can be negatively impacted when the resolution of the iris images is low which results in failure to determine the eye center, limbic and pupillary boundary of the iris segmentation. Hence, a combination with periocular features is suggested to increase the authenticity of the recognition system. However, the texture feature of periocular can be easily affected by a background complication while the colour feature of periocular is still limited to spatial information and quantization effects. This happens due to different distances between the sensor and the subject during the iris acquisition stage as well as image size and orientation. The proposed method of periocular feature extraction consists of a combination of rotation invariant uniform local binary pattern to select the texture features and a method of color moment to select the color features. Besides, a hue-saturation-value channel is selected to avoid loss of discriminative information in the eye image. The proposed method which consists of combination between texture and colour features provides the highest accuracy for the periocular recognition with more than 71.5% for the UBIRIS.v2 dataset and 85.7% for the UBIPr dataset. For the fusion recognitions, the proposed method achieved the highest accuracy with more than 85.9% for the UBIRIS.v2 dataset and 89.7% for the UBIPr dataset

Numerical analysis of carrier statistics in low-dimensional nanostructure devices

The carrier statistics for low-dimensional nanostructure is elaborated. The density of state (DOS) is proportional to d D ? where d is the dimensionality of the nanostructure and D ? is the De- Broglie wavelength proportion of Fermi-Dirac (FD) integral that covers the carrier statistics to all degeneracy level. In the non-degenerate regime the results replicate what is expected from the Boltzmann statistics. However, the results vary in degenerate regime. The results for all dimensions are numerically analyzed and compared for all three Cartesian directions. With appropriate DOS, the carrier concentration in all dimensions is obtained based on the FD statistic. Fermi energy with respect to band edge is a function of temperature that is independent of the carrier concentration in the non-degenerate regime. In the strongly degenerate regime, the Fermi energy is a function of carrier concentration appropriate for given dimensionality, but is independent of temperature

How Can We Identify Hijacked Journals?

By developing research and academic centers, the number of performed research articles has also increased. On the other hand, publishing the results of these articles in scientific journals shall also grow. In the meantime, researchers are trying to publish the findings of their research in journals which have been approved by one or more international indices so that such findings can be seen. In order to enhance the academic standards of Universities, proper journal choice will be of interest to researchers, especially those that are indexed in websites such as Thomson Reuters. However, certain forgery frauds researchers by launching fake Web sites that have been named by academic journal titles. In this paper, we introduce an approach to identify this type of journals that will be applicable by researchers in various academic disciplines

Vertical double gate MOSFET for nanoscale device with fully depleted feature

A fully depleted vertical double gate MOSFET device was revealed with the implementation of oblique rotating implantation (ORI) method in 25 nm silicon pillar thickness. Several devices with various gate lengths (20 - 100 nm) were simulated and evaluated using virtual wafer tool. The implication of gate length reduction on the short channel effect (SCE) shows considerable advantages with higher current drives at lower gate length, while the low subthreshold swing could balance the threshold voltage roll-off in the term of increasing power consumption. As a result, the drive current and also SCE controllability will be a benefit in the fully depleted device