Sistem pemantauan transformer dengan IoT

Artikel ini sebagai laporan untuk kajian yang berkaitan transformer dan sistem pemantauan masa nyata. Dalam dekad yang lalu, banyak perhatian dibuat untuk memperkenalkan sistem pintar dan peralatan untuk memenuhi keperluan semasa dan menjadikan kehidupan selesa. Satu kepentingan baru-baru ini dalam komunikasi Mesin ke Mesin dikenali sebagai Internet of Things (IOT), untuk membolehkan peranti autonomi menggunakan Internet untuk bertukar data. Kerja-kerja ini membentangkan reka bentuk dan pelaksanaan pemantauan masa nyata dan pengesanan kesalahan pengubah dan rekod penunjuk operasi utama pengubah penyebaran seperti beban semasa, voltan, minyak pengubah dan merangkumi suhu dan kelembapan. Transformer adalah salah satu peralatan elektrik yang paling penting yang digunakan dalam sistem penghantaran kuasa kerana mereka melaksanakan fungsi mengubah tahap voltan. Oleh itu, penyelenggaraan pengubah kuasa adalah wajib; kerana ia terletak di kawasan geografi yang berbeza, pemantauan berkala tidak mungkin sepanjang masa disebabkan oleh tenaga manusia yang tidak mencukupi. Sekiranya ada sesuatu yang tidak normal atau keadaan kecemasan berlaku, sistem itu boleh dipantau melalui internet yang mengandungi maklumat tentang ketidaknormalan mengikut beberapa arahan yang telah ditetapkan yang diprogramkan dalam mikrokontroler. Sistem ini akan membantu transformer untuk beroperasi dengan lancar dan mengenal pasti masalah sebelum sebarang kegagalan bencana

Cyclic Self-Organizing Map for Object Recognition

Object recognition is an important machine learning (ML) application. To have a robust ML application, we need three major steps: (1) preprocessing (i.e. preparing the data for the ML algorithms); (2) using appropriate segmentation and feature extraction algorithms to abstract the core features data and (3) applying feature classification or feature recognition algorithms. The quality of the ML algorithm depends on a good representation of the data. Data representation requires the extraction of features with an appropriate learning rate. Learning rate influences how the algorithm will learn about the data or how the data will be processed and treated. Generally, this parameter is found on a trial-and-error basis and scholars sometimes set it to be constant. This paper presents a new optimization technique for object recognition problems called Cyclic-SOM by accelerating the learning process of the self-organizing map (SOM) using a non-constant learning rate. SOM uses the Euclidean distance to measure the similarity between the inputs and the features maps. Our algorithm considers image correlation using mean absolute difference instead of traditional Euclidean distance. It uses cyclical learning rates to get high performance with a better recognition rate. Cyclic-SOM possesses the following merits: (1) it accelerates the learning process and eliminates the need to experimentally find the best values and schedule for the learning rates; (2) it offers one form of improvement in both results and training; (3) it requires no manual tuning of the learning rate and appears robust to noisy gradient information, different model architecture choices, various data modalities and selection of hyper-parameters and (4) it shows promising results compared to other methods on different datasets. Three wide benchmark databases illustrate the efficiency of the proposed technique: AHD Base for Arabic digits, MNIST for English digits, and CMU-PIE for faces

LptO (PG0027) is required for lipid A 1-phosphatase activity in Porphyromonas gingivalis W50

ABSTRACT Porphyromonas gingivalis produces outer membrane vesicles (OMVs) rich in virulence factors, including cysteine proteases and A-LPS, one of the two lipopolysaccharides (LPSs) produced by this organism. Previous studies had suggested that A-LPS and PG0027, an outer membrane (OM) protein, may be involved in OMV formation. Their roles in this process were examined by using W50 parent and the Δ PG0027 mutant strains. Inactivation of PG0027 caused a reduction in the yield of OMVs. Lipid A from cells and OMVs of P. gingivalis W50 and the Δ PG0027 mutant strains were analyzed by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). Lipid A from W50 cells contained bis-P-pentaacyl, mono-P-pentaacyl, mono-P-tetraacyl, non-P-pentaacyl, and non-P-tetraacyl species, whereas lipid A from Δ PG0027 mutant cells contained only phosphorylated species; nonphosphorylated species were absent. MALDI-TOF/TOF tandem MS of mono-P-pentaacyl ( m / z 1,688) and mono-P-tetraacyl ( m / z 1,448) lipid A from Δ PG0027 showed that both contained lipid A 1-phosphate, suggesting that the Δ PG0027 mutant strain lacked lipid A 1-phosphatase activity. The total phosphatase activities in the W50 and the Δ PG0027 mutant strains were similar, whereas the phosphatase activity in the periplasm of the Δ PG0027 mutant was lower than that in W50, supporting a role for PG0027 in lipid A dephosphorylation. W50 OMVs were enriched in A-LPS, and its lipid A did not contain nonphosphorylated species, whereas lipid A from the Δ PG0027 mutant (OMVs and cells) contained similar species. Thus, OMVs in P. gingivalis are apparently formed in regions of the OM enriched in A-LPS devoid of nonphosphorylated lipid A. Conversely, dephosphorylation of lipid A through a PG0027-dependent process is required for optimal formation of OMVs. Hence, the relative proportions of nonphosphorylated and phosphorylated lipid A appear to be crucial for OMV formation in this organism. IMPORTANCE Gram-negative bacteria produce outer membrane vesicles (OMVs) by “blebbing” of the outer membrane (OM). OMVs can be used offensively as delivery systems for virulence factors and defensively to aid in the colonization of a host and in the survival of the bacterium in hostile environments. Earlier studies using the oral anaerobe Porphyromonas gingivalis as a model organism to study the mechanism of OMV formation suggested that the OM protein PG0027 and one of the two lipopolysaccharides (LPSs) synthesized by this organism, namely, A-LPS, played important roles in OMV formation. We suggest a novel mechanism of OMV formation in P. gingivalis involving dephosphorylation of lipid A of A-LPS controlled/regulated by PG0027, which causes destabilization of the OM, resulting in blebbing and generation of OMVs. </jats:p

Fabrication and characterization of crystalline cupric oxide (CUO) films by simple immersion technique

Cupric oxide (CuO) is one of the most promising p-type semiconducting materials used in p-n junction solar cells. Most of the researchers use electrochemical deposition (ECD) to deposit CuO film. However, it always requires a conductive substrate and the resulting film is porous. In this work, we demonstrated a simple method using an immersion technique to deposit nanostructured CuO for p-n solar cell application. Compared to ECD which end up with only pyramid-like structure, an immersion technique offers flexibility on the CuO nanostructures such as spheres, particles, diamond etc. This technique also offers higher deposition rate which allow deposition at thicker thickness. The adherence to the substrate can be manipulated depending on the pH of the solution. The resuling film was tested into a p-n solar cell using configuration of Au/ZnO/Cuo/ITO/glass. Although there is no efficiency obtained under the solar radiation, it shows a solar cell characteristic with open circuit voltage (Voc) of 1.5

Graphene as a buffer layer for silicon carbide-on-insulator structures

We report an innovative technique for growing the silicon carbide-on-insulator (SiCOI) structure by utilizing polycrystalline single layer graphene (SLG) as a buffer layer. The epitaxial growth was carried out using a hot-mesh chemical vapor deposition (HM-CVD) technique. Cubic SiC (3C-SiC) thin film in (111) domain was realized at relatively low substrate temperature of 750 °C. 3C-SiC energy bandgap of 2.2 eV was confirmed. The Si-O absorption band observed in the grown film can be caused by the out-diffusion of the oxygen atom from SiO2 substrate or oxygen doping during the cleaning process. Further experimental works by optimizing the cleaning process, growth parameters of the present growth method, or by using other growth methods, as well, are expected to realize a high quality SiCOI structure, thereby opening up the way for a breakthrough in the development of advanced ULSIs with multifunctionalities

Error correction and uncertainty measurement of short-open-load calibration standards on a new concept of software defined instrumentation for microwave network analysis

Software-Defined Radio (SDR) has appeared as a sufficient framework for the development and testing of the measurement systems such as a signal generator, signal analyzer, and network analysis used in the network analyzer. However, most of researchers or scientists still rely on commercial analyzers were larger benchtop instruments, highly cost investment and minimum software intervention. In this paper, a new concepts measurement revolution called as Software Defined Instrumentation (SDI) on network analysis is presented, which is based on reconfigurable SDR, a low-cost implementation, ability to access RF chain and utilizing open source signal processing framework. As a result, a Vector Network Analyzer (VNA) has been successful implemented by deploying an SDR platform, test sets, and data acquisition from the GNU Radio software in host PC. The known calibration process on SHORT-OPEN-LOAD (SOL) technique is validated to ensure measurement data from this SDI free from systematic error. Two types of SOL calibration standards used for a comparison study to validate the SDI measurement system which is capable of generating the response on the differential of standard quality and accuracy of standards kits. Finally, calibration uncertainty analysis is also presented in this work by utilizing RF open source package without any cost addition

Numerical investigation on the hydrodynamic characteristics of an autonomous underwater glider with different wing layouts

An autonomous underwater glider is a self-propelled underwater vehicle which is designed primarily for oceanography. It moves with low speed in saw-tooth pattern and has long endurance. The vertical motion of the glider is controlled by changing its buoyancy and its wings convert this vertical motion into horizontal motion. The hydrodynamic coefficients of glider will dictate its performance and possible applications. In this paper, the impact of rectangular and tapered wings on the hydrodynamics coefficient of a glider and the corresponding glide velocity was investigated using ANSYS Computational Fluid Dynamics (CFD) turbulence model and FLUENT flow solver. The lift force of a rectangular wing is higher with less drag force compared to tapered wings. A glider with tapered wings glider will have a larger glide angle and is therefore suitable of deep ocean applications

Effect of wing form on the hydrodynamic characteristics and dynamic stability of an underwater glider

We are developing a prototype underwater glider for subsea payload delivery. The idea is to use a glider to deliver payloads for subsea installations. In this type of application, the hydrodynamic forces and dynamic stability of the glider is of particular importance, as it has implications on the glider's endurance and operation. In this work, the effect of two different wing forms, rectangular and tapered, on the hydrodynamic characteristics and dynamic stability of the glider were investigated, to determine the optimal wing form. To determine the hydrodynamic characteristics, tow tank resistance tests were carried out using a model fitted alternately with a rectangular wing and tapered wing. Steady-state CFD analysis was conducted using the hydrodynamic coefficients obtained from the tests, to obtain the lift, drag and hydrodynamic derivatives at different angular velocities. The results show that the rectangular wing provides larger lift forces but with a reduced stability envelope. Conversely, the tapered wing exhibits lower lift force but improved dynamic stability