364 research outputs found
Ant colony algorithm for web page classification
As the information contained in the web is increasing, organizing this information is a necessary requirement. Classification is a way to organize the web's information. While there is different ways to classify the web information, swarm intelligence is a new one in this field.
This paper investigates usage of a swarm intelligence algorithm in the field of the web page classification; Focusing on Persian web pages. Ant Miner II is the used algorithm. It also propose a simple text preprocessing technique to reduce the large numbers of attributes associated with web content mining, without dealing linguistic complications. The result shows Ant Miner II and proposed preprocessing technique are efficiency in the field of the web page classification
Single-, Dual- and Triple-band Frequency Reconfigurable Antenna
The paper presents a frequency reconfigurable slot dipole antenna. The antenna is capable of being switched between single-band, dual-band or triple-band operation. The antenna incorporates three pairs of pin-diodes which are located within the dipole arms. The antenna was designed to operate at 2.4 GHz, 3.5 GHz and 5.2 GHz using the aid of CST Microwave Studio. The average measured gains are 1.54, 2.92 and 1.89 dBi for low, mid and high band respectively. A prototype was then constructed in order to verify the performance of the device. A good level of agreement was observed between simulation and measurement
An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency
In this paper, an electronically polarization reconfigurable circular patch antenna with fixed resonant frequency operating at Wireless Local Area Network (WLAN) frequency band (2.4-2.48 GHz) is presented. The structure of the proposed design consists of a circular patch as a radiating element fed by coaxial probe, cooperated with four equal-length slits etched on the edge along x-axis and y-axis. A total of four switches was used and embedded across the slits at specific locations, thus controlled the length of the slits. By activating and deactivating the switches (ON and OFF) across the slits, the current on the patch is changed, thus modifying the electric field and polarization of the antenna. Consequently, the polarization excited by the proposed antenna can be switched into three types, either linear polarization, left-hand circular polarization or right-hand circular polarization. This paper proposes a simple approach that able to switch the polarizations and excited at the same operating frequency. Simulated and measured results of ideal case (using copper strip switches) and real case (using PIN diode switches) are compared and presented to demonstrate the performance of the antenna
Flexural behaviour of plain concrete prism strengthened by textile fine grained mortar
This paper presents a flexural strength study of concrete incorporated with textile fine grained mortar (TFGM) as a strengthening laminate. TFGM is a combination of fine grained mortar (FGM) with alkali resistant glass fabric (AR glass). Fine grained sand with 600 m maximum size was used in FGM and fly ash (FA) or rice husk ash (RHA) has been used as a partial substitute for ordinary Portland cement (OPC). The potential of TFGM as strengthening laminate was tested under monolithic load with three point flexure loading. The TFGM were laid in layers of two, four, six, and eight. Results shown a promising flexure enhancement of up to three times of unstrengthened concrete when eight layers of both RHA and FA were laid. Load bearing capacity and ductility of the samples increased about 200% and 61%, respectively, compared to control samples as well. The outcome shows a highly potential use of agro-waste as cement replacement to produce load bearing structural component
Physico-mechanical properties of polymer concrete containing micro-filler of palm oil fuel ash
Objective of this study is to present a research conducted on ground (fine) and unground (coarse) POFA in polymer concrete (PC) followed by determination on the physico-mechanical properties of PC. Physical properties of micro-fillers and mechanical properties of produced PCs were characterized. Calcium carbonate and silica sand were also used as micro-fillers for comparison purpose. The samples were subjected to compression and flexural. Morphology images of the particles were captured under morphology test to support the findings. Results showed that fine POFA micro-filler has a highly promising potential in becoming PC filler compared to coarse micro-filler. Additionally, its produced PC had comparable strength to PC with calcium carbonate. From the strength development and sustainability stand point, fine POFA has demonstrated its capability to produce quality and sustainable P
Mutual Coupling Reduction in Antenna Using EBG on Double Substrate
In this paper, a mutual coupling studies is conducted between two-element array antenna on dual substrate. A single patch antenna is firstly designed on dual substrate layer to testify appropriate performance at 2.45 GHz. Subsequently, an array of two element patches on dual substrate are constructed with one of them is incorporated with three EBG unit cell on the bottom substrate. The radiating patch is on the top substrate, while the EBG unit cells is on the bottom substrate. With EBGs in separate layers from the antenna array, the antenna elements are closely separated by a distance of 22 mm with a significant reduced mutual coupling of -26.61 dB. This correspond to a distance reduction of 34.68%. The proposed structure implemented only three EBG unit cells. Apart from that, the study of overlapped case of EBG with the antenna is also presented
Thermal Conductivity Of Lightweight Concrete Block With Various Cooling Agent
Energy was the important sources to human life. Due to increases energy demand in daily life, the energy consumption was increase day by day because of the heat load from solar radiation and heat produced by people. Toward sustainable development, this research was carried out to develop a lightweight concrete (LWC) block with various cooling agent such as glycerine, propylene glycol, coconut shell and gypsum powder. Six lightweight concrete (LWC) block with the size 250mm (L) × 250mm (W) × 100mm (T) were tested for thermal conductivity value. From the experimental result, it shows that lightweight concrete (LCW) block with various cooling agent obtained thermal conductivity value of 0.17W/mK - 0.36W/mK lower than thermal conductivity value for normal lightweight concrete (0.8W/mK) depending on concrete density. The lightweight concrete (LCW) block with cooling agent having low thermal conductivity value will reduce energy consumption in building
Band-pass Filter with Harmonics Suppression Capability
This paper presents a Band-pass Filter (BPF) with a very wide suppressions band. The filter design is based on a modified U-shaped slot. Two pair of U-shaped slots is used to ensure that the filter can suppress the unwanted frequencies up to 4th harmonics. In order to achieve sharp skirt, two transmission zeroes are created near the passband area. Additional transmission zeroes are introduced to deepen the stopband area. Therefore, the passband range starts from 1.3 to 3.3 GHz and the stopband range from 3.3 GHz up to 9 GHz are achieved. The filter performances are verified through simulated and measured results
Dual Band to Wideband Pentagon-shaped Patch Antenna with Frequency Reconfigurability using EBGs
A dual band to wideband reconfigurable pentagon-shaped antenna with EBG unit cell is proposed. A minimal number of two EBG unit cell is deployed to realize frequency reconfigurable mechanism. By varying the state of the EBG the antenna is capable to change its dual band operation to wideband alternately. There are three cases that have been analysed, first case is the EBG incorporated antenna with ideal and second is with the active EBG. Subsequently, the third cases is the fabricated ideal EBG incorporated antenna. The dual band operation is at 1.8 GHz and 5.2 GHz while the wide band from 1.6 GHz to 2.37 GHz (770 MHz). The proposed reconfigurable antenna is suitable to be implemented for LTE (1.6 GHz), Wi-Fi (5.2 GHz), WiMAX (2.3 GHz) and cognitive radio application
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