Time filter

Source Type

Raksuntorn N.,Suan Sunandha Rajabhat University | Du Q.,Mississippi State University
IEEE Geoscience and Remote Sensing Letters | Year: 2010

Nonlinear spectral mixture analysis for hyperspectral imagery is investigated without prior information about the image scene. A simple but effective nonlinear mixture model is adopted, where the multiplication of each pair of endmembers results in a virtual endmember representing multiple scattering effect during pixel construction process. The analysis is followed by linear unmixing for abundance estimation. Due to a large number of nonlinear terms being added in an unknown environment, the following abundance estimation may contain some errors if most of the endmembers do not really participate in the mixture of a pixel. We take advantage of the developed endmember variable linear mixture model (EVLMM) to search the actual endmember set for each pixel, which yields more accurate abundance estimation in terms of smaller pixel reconstruction error, smaller residual counts, and more pixel abundances satisfying sum-to-one and nonnegativity constraints. © 2006 IEEE.


This paper presents the design of a current-mode quadrature sinusoidal oscillator. It can generate two current-mode sinusoidal outputs with 90 degree phase difference called as quadrature signal. The proposed sinusoidal oscillator employs single differential voltage current conveyer transconductance amplifier (DVCCTA), two grounded capacitors and three resistors. The tuning of frequency of oscillation (FO) and condition of oscillation (CO) can be done independently. Also the frequency of oscillation can be electronically tuned which is suitable for modern control system using microcontroller or microprocessor. The impedance at output node is high impedance which can directly drive an external load or connect to another circuit without the use of current buffers. A number of simulation results based on PSPICE program using 0.25 μm TSMC CMOS parameters are included to exhibit performance, workability and effectiveness of the proposed sinusoidal oscillator. © 2016, Wydawnictwo SIGMA - N O T Sp. z o.o. All rights reserved.


In this study, a current-mode quadrature sinusoidal oscillator using single current controlled current differencing transconductance amplifier (CCCDTA) and 2 grounded capacitors is proposed. The proposed oscillator can provide 2 sinusoidal output currents with 90 phase difference. The oscillation condition and oscillation frequency can be controlled electronically by adjusting the bias current of the CCCDTA. The oscillator configuration exhibits high output impedance which makes easy to drive loads without using any buffering devices. The use of only grounded capacitors is ideal for integration. The circuit performances are depicted through PSpice simulations, they show good agreement to theoretical assumptions.


Jomsri P.,Suan Sunandha Rajabhat University
4th International Conference on Innovative Computing Technology, INTECH 2014 and 3rd International Conference on Future Generation Communication Technologies, FGCT 2014 | Year: 2014

Due to wide application of management system, information data grows rapidly. On one hand, people have a large number of information resources. On the other hand, the time cost and difficulty of people finding the proper information increases. To tackle the problems, book recommendation is one of the solutions for university libraries which possess huge volumes of books and reading-intensive users. This paper proposes a library book recommendation system based on user profile loaning and apply association rule to create model. The result shows that new association rule algorithm suitable to apply for recommender book in library. © 2014 IEEE.


Thaipratum R.,Suan Sunandha Rajabhat University
Key Engineering Materials | Year: 2016

Today, Use of the natural reducer in the green synthesis of metallic nanoparticles has gained more attention due to the development of eco-friendly technologies in materials science that emphasised in environment-friendly chemicals, solvents and renewable materials. In the present work, bread crust, Browning product of thermally processed bread, extracts have been determined for reducing property by using DPPH and hydroxyl radical scavenging assay. The results showed that bread crust extracts have promising reducing property for the green synthesis of metallic nanoparticles. © 2016 Trans Tech Publications, Switzerland.


Rattanavadi S.,Suan Sunandha Rajabhat University
Key Engineering Materials | Year: 2016

Waste recycling was interested to both industrial and academic sectors. This study focuses on the use of sludge cake from wastewater treatment plant of a cosmetic industry as Magnesium oxide source. Cordierite obtains good chemical corrosion resistance, fine mechanical properties, good thermal conductivity, and most of all low coefficient of thermal expansion (COE) which is needed for ceramics industry. Magnesium is one of the main materials in cordierite, can be attained from different sources. In this research, Sludge cake from cosmetic industry was used as Magnesium sources for cordierite synthesis. The raw materials were ground, pressed, and sintered between 1200°C to 1325°C for 1 hour. The samples were investigated by X-ray diffraction technique and tested for thermal shock resistance, firing shrinkage, and water absorption. The XRD patterns showed that the increasing intensity of cordierite phase, the higher firing temperature presented the greater of cordierite phases. The findings were confirmed by the peaks of cordierite at 2θ of 10.41° of samples when fired at 1325°C. It can be concluded that cordierite could be synthesized by using raw material from waste with other commercial raw material in different temperatures. Results showed that the sludge cake from wastewater treatment plant of Cosmetic Industry in Thailand is a promising as raw material and beneficial to Thai ceramics industry in terms of cost saving, competitiveness and environmental. © 2016 Trans Tech Publications, Switzerland.


Jaikla W.,Suan Sunandha Rajabhat University | Lahiri A.,36 B
AEU - International Journal of Electronics and Communications | Year: 2012

Abstract: A current-mode four-phase quadrature oscillator (FPQO) using 2 current controlled current differencing transconductance amplifiers (CCCDTAs) and 2 grounded capacitors is presented. The proposed oscillator can provide 4 sinusoidal output currents with 90 phase difference. The oscillation condition and oscillation frequency can be controlled independently and electronically by adjusting the bias currents of the CCCDTA. Both the oscillation condition and oscillation frequency tuning laws are non-interactive and dual-current controlled. High output impedances of the configuration enable the circuit to be cascaded without additional current buffers. The use of only grounded capacitors is ideal for integration. The circuit performances are depicted through PSPICE simulations, they show good agreement to theoretical anticipation. © 2011 Elsevier GmbH. All rights reserved.


An implementation of current-mode multiphase sinusoidal oscillators is presented. Using CCCCTA-based lossy integrators, odd and odd/even phase systems can be realised with following advantages. The condition of oscillation and frequency of oscillation can be electronically/orthogonally tuned. The high output impedances facilitate easy driving an external load without additional current buffers. The proposed MSOs provide odd or even phase signals that are equally spaced in phase and equal amplitude. The circuit requires one CCCCTA and one grounded capacitor per phase without external resistor and additional current amplifier. The effects of the non-idealities of the CCCCTA-lossy integrator sections were also studied. The results of PSPICE simulations using BJT CCCCTA are included to verify theory.


Jaikla W.,Suan Sunandha Rajabhat University | Prommee P.,King Mongkut's University of Technology Thonburi
Radioengineering | Year: 2011

This study describes the design of a multiphase sinusoidal oscillator (MSO) using CCCDTA-based allpass filters with grounded capacitors. The oscillation condition and oscillation frequency can be electronically/orthogonally controlled. The proposed MSO provides 2n (n ≥ 2) phase signals that are equally spaced in phase and equal amplitude. The circuit requires one CCCDTA, one electronic resistor and one grounded capacitor per phase and no additional current amplifier and floating elements. High output impedances of the configuration enable the circuit to be cascaded to the current-mode circuit without additional current buffers. The effects of the non-idealities of the CCCDTA-allpass sections were also studied. The results of PSPICE simulations using CMOS CCCDTA are presented, demonstrating their consistency with theoretical assumptions.


Jaikla W.,Suan Sunandha Rajabhat University | Siripruchyanun M.,King Mongkut's University of Technology Bangkok
Analog Integrated Circuits and Signal Processing | Year: 2010

This letter presents a realization of voltage-mode quadrature sinusoidal oscillator with independent current tunable frequency of oscillation. The circuit uses a single differential voltage current conveyor transconductance amplifier (DVCCTA) as the active building block and four all grounded passive elements. PSPICE simulation results have been included to verify the theoretical results. © 2010 Springer Science+Business Media, LLC.

Loading Suan Sunandha Rajabhat University collaborators
Loading Suan Sunandha Rajabhat University collaborators