1,720,983 research outputs found
Sistem pintar pengecaman bentuk agregat berasaskan rangkaian neural
No full textPenghasilan sesebuah konkrit bergantung kepada kandungan agregat (batu baur) yang
terkandung di dalam konkrit tersebut. Bentuk agregat-agregat yang terdapat di dalam
konkrit dikatakan mempengaruhi kualiti konkrit yang akan dihasilkan. Agregat yang
mempunyai bentuk yang dikatakan elok (well-shaped) akan menghasilkan konkrit yang
bermutu tinggi dengan mengurangkan kadar air kepada simen di dalam konkrit.
Sebaliknya, bentuk agregat-agregat yang buruk (poor-shaped) selalunya menyebabkan
penghasilan sesebuah konkrit itu memerlukan kadar air kepada simen yang tinggi.
Kebiasaannya, kualiti sesebuah konkrit ditentukan dengan mengira kadar peratusan
kandungan agregat yang elok kepada agregat yang buruk yang terkandung di dalam
konkrit. Masalah penentuan secara manual ini ialah lambat, terlalu subjektif dan
memerlukan tenaga buruh yang ramai, sekaligus menyebabkan tidak efektif dan mahal.
Dalam usaha untuk mengurangkan masalah ini, penyelidikan yang dilakukan telah
memfokuskan kepada pembangunan sistem pengecaman pintar bentuk agregat
berasaskan rangkaian neural. Sistem yang dibangunkan menggunakan teknik
pemprosesan imej digital dan rangkaian neural untuk mengkelaskan bentuk-bentuk
agregat yang diperolehi kepada dua kategori, "elok" dan "buruk". Sistem ini merangkumi
dua bahagian utama iaitu pengekstrakan ciri-ciri imej dan pengecaman. Dalam bahagian
pengekstrakan ciri-ciri imej, ciri-ciri yang dipertimbangkan ialah momen Zernike, momen
Hu, saiz dan ukurlilit. Pengekstrakan ciri-ciri momen Zernike dan momen Hu dikira
berdasarkan kepada saiz dan ukurlilit objek. Disebabkan momen Hu peringkat tinggi lebih
sensitif kepada hingar, maka hanya momen Hu peringkat pertama dan kedua sahaja digunakan. Bagi ciri momen Zernike pula, nilai momen yang digunakan ialah jumlah
penambahan nilai momen Zernike dari tertib 0 hingga tertib 4 kerana ia memberikan
keputusan perkelompokan yang lebih baik. Dalam bahagian pengecaman, rangkaian
neural yang dibangunkan ialah rangkaian hibrid berbilang lapisan perceptron (HMLP).
Rangkaian tersebut telah dilatih menggunakan algoritma ralat ramalan berulang
terubahsui (MRPE) dan memberikan prestasi pengecaman sebanyak 85.53%. Ini
membuktikan sistem pengecaman bentuk agregat secara automatik yang dibangunkan
berjaya mengkelaskan bentuk-bentuk agregat kepada dua kategori iaitu "elok" dan
"buruk". Sebagai langkah awal untuk menghasilkan sistem pengecaman bentuk agregat
mudah alih, sistem pengecaman menggunakan mikro pengawal juga telah dihasilkan dan
dibuktikan keberkesanan dan kebolehpercayaannya. Sistem pengecaman yang
berasaskan mikro pengawal ini telah menghasilkan peratus pengecaman yang sama
nilainya dengan peratus pengecaman yang diperolehi menggunakan komputer peribadi
Modulation techniques for GPR system radargram
Full text linkGround Penetrating Radar (GPR) system ability to detect embedded object
underground is dependent on the ultra-wideband antenna use. Based on this antenna
type, the fractional bandwidth used by the GPR system is usually greater or equal to
1. On the other hand, the GPR system using fractional bandwidth less than 1 will
produce unsmooth GPR radargram, as the consequences of high signal ripples
generated in the system output signals. Based on fractional bandwidth parameter, this
study focuses in developing a digital signal processing of the GPR system to produce
a smooth GPR radargram. The proposed GPR signal processing system is based on
envelope detector technique of Asynchronous Half-Wave (AHW), Asynchronous
Full-Wave (AFW) and Asynchronous Real Square Law (ARSL). The Pulse
Modulation (PM), Stepped Frequency Continuous Wave (SFCW) and Hybrid GPR
system simulation are modeled using CST Studio Suite and MATLAB software. The
selected fractional bandwidth of the GPR system simulation modeled is 0.46 and 0.4
for Microstrip Vivaldi and Horn antennas respectively. In addition, a practical
implementation of the SFCW and Hybrid GPR system using fabricated Microstrip
Vivaldi antenna having a fractional bandwidth of 0.46 and VNA equipment, was
conducted. Based on the analysis results of the proposed PM GPR system simulation,
the AFW technique produces clearer PM GPR radargram. The detection rate for PM
GPR system simulation using AFW technique is 87% and 51.3% using Horn and
Microstrip Vivaldi antennas respectively. Practical implementation of SFCW and
Hybrid GPR systems using AFW technique and Microstrip Vivaldi antenna can detect
an iron and a bottle filled with water object
Characterization of pulse forming networks / Ariffuddin Joret
No full textPulse Power Technology is another subdivision being embarked recently. This field is very synonym to High Voltage Engineering, which deals with thousands of volt in small range of current. The generation of high voltage impulse is a prime requirement prior to the actual testing process. Impulse signal could be generated using solid-state devices and even to the application of coaxial cable, which is capable in producing high voltage impulse. This set-up is widely known as Pulse Forming Networks (PFN). This thesis presents the characteri zation of PFN model using coaxial cable, simulation through Microcap5 and experimentation of various models. Various construction of PFN were carried out such as Single Pulse Forming Line, Open Transmission Line and Stacked-Blumlein Generator. Results obtained from the laboratory experiment indicated that an agreement with the theoretical prediction is accomplished
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
SIMULATION OF GPR SYSTEM DESIGN USING CST MICROWAVE AND MATLAB
No full textGround Penetrating Radar (GPR) is a radar system used to detect objects buried underground. The GPR system consists of an antenna which will be used as a sensor device in detecting microwave signal generated by it, which called monostatic or two antennas used as transmitter and receiver antenna known as bistatic GPR system. In the development of a GPR system, it is wise to simulate the GPR system using simulation software such as CST microwave software in order to reduce errors in determining the parameters of the system such as antenna\u27s dimension and signal processing system. The design of the simulation system of the GPR system in this study started from designing an antenna, where the microstrip patch antenna has been chosen. The simulation of the design antenna was then upgraded by the designing of the ground material in front of the antenna to create a medium of transmission such as sandy soil. In order to observe the capability of the designed antenna as the GPR antenna system as well as the signal processing system, the buried material in the ground has been added. As the consideration of the GPR system is on the bistatic GPR system, the antenna will be paired between the transmitting and receiving antenna. Based on the commercial GPR system, the simulation of the GPR system will also be interpreted as a 2 dimensional image using MATLAB software
A Design of Low Power Single Axis Solar Tracking System Regardless of Motor Speed
Full text linkSolar power generation had been used as a renewable energy since years ago. Residential that uses solar power as their alternative power supply will bring benefits to them. The main objective of this paper is to present development of an automatic solar tracking system whereby the system will caused solar panels will keep aligned with the Sunlight in order to maximize in harvesting solar power. The system focuses on the controller design whereby it will caused the system is able to tracks the maximum intensity of Sunlight is hit. When the intensity of Sunlight is decreasing, this system automatically changes its direction to get maximum intensity of Sunlight. LDR light detector acts as a sensor is used to trace the coordinate of the Sunlight by detecting brightness level of Sunlight. While to rotate the appropriate position of the panel, a DC-geared motor is used. The system is controlled by two relays as a DC-geared motor driver and a microcontroller as a main processor. This project is covered for a single axis and is designed for low power and residential usage applications. From the hardware testing, the system is able to track and follow the Sunlight intensity in order to get maximum solar power at the output regardless motor speed
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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