Supriyo,Dey; Aanandan,C K; Mohanan, P; K G Nair(Microwave and Optical Technology Letters, September , 1994)
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Abstract:
A simple technique to improve the impedance bandwidth of a circular
microstrip patch antenna using two sectorial slots is proposed. Using this
design more than 5% impedance bandwidth is obtained. The added
advantage of this new antenna is that it can be fed by a 50- microstrip line
Manju,Paulson; Sona,Kundukulam O; Aanandan,C K; Mohanan, P(Microwave and Optical Technology Letters, June 5, 2001)
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Abstract:
A new compact dual-band, dual-polarized microstrip antenna
is presented. 7'iris antenna resonates at two frequencies with
different polarizations: a linearly polarized one for terrestrial
communication, and a circularly polarized one for satellite mobile
communication. This antenna also provides an area reduction of 70%
compared to a standard rectangular patch antenna
George,J; Deepukumar,M; Aanandan,C K; Mohanan, P; K G Nair(Department of Electronics, March , 1996)
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Abstract:
A new microstrip antenna geometry with considerable reduction
in size, with similar radiation characteristics to those of an
equivalent rectangular patch antenna is proposed. A relationship
has been suggested for fmding out the resonant frequency of the
new geometry, and its validity has been established by the
experimental results. Without increasing the aperture area, this
geometry also offers a facility for considerably reducing the
resonant frequency compared to conventional patches.
Sebastian, Mathew; Joe, Jacob; Joseph, V P; Bijukumar, S; Raveendranath, U; Mathew, K T(John Wiley & Sons, March 5, 1999)
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Abstract:
This paper presents the design of a new type of corner reflector (CR) antenna and the experimental investigation of its radiation characteristics. The design involves the addition of planar parallel periodic strips to the two sides of a CR antenna. The position, angular orientation, and number of strips have a notable effect on the H-plane radiation characteristics of the antenna. Certain configurations of the new antenna are capable of producing very sharp axial beams with gain on the order of 5 dB over the square corner reflector antenna. A configuration that can provide symmetric twin beams with enhanced gain and reduced half-power beam width (HPBW) is also presented.
Tessamma, Thomas; Deepa, Sankar(Society for Imaging Informatics in Medicine, October , 2010)
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Abstract:
In this paper, a novel fast method for modeling mammograms
by deterministic fractal coding approach to detect
the presence of microcalcifications, which are early
signs of breast cancer, is presented. The modeled
mammogram obtained using fractal encoding method is
visually similar to the original image containing microcalcifications,
and therefore, when it is taken out from
the original mammogram, the presence of microcalcifications
can be enhanced. The limitation of fractal image
modeling is the tremendous time required for encoding.
In the present work, instead of searching for a matching
domain in the entire domain pool of the image, three
methods based on mean and variance, dynamic range of
the image blocks, and mass center features are used.
This reduced the encoding time by a factor of 3, 89, and
13, respectively, in the three methods with respect to
the conventional fractal image coding method with quad
tree partitioning. The mammograms obtained from The
Mammographic Image Analysis Society database
(ground truth available) gave a total detection score of
87.6%, 87.6%, 90.5%, and 87.6%, for the conventional
and the proposed three methods, respectively.
Description:
Journal of Digital Imaging, Vol 23, No 5 (October), 2010: pp 538-546
Tessamma, Thomas; Deepa, J(The International Institute for Science, Technology and Education (IISTE), 2013)
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Abstract:
As the technologies for the fabrication of high quality microarray advances rapidly, quantification of
microarray data becomes a major task. Gridding is the first step in the analysis of microarray images for
locating the subarrays and individual spots within each subarray. For accurate gridding of high-density
microarray images, in the presence of contamination and background noise, precise calculation of
parameters is essential. This paper presents an accurate fully automatic gridding method for locating
suarrays and individual spots using the intensity projection profile of the most suitable subimage. The
method is capable of processing the image without any user intervention and does not demand any input
parameters as many other commercial and academic packages. According to results obtained, the accuracy
of our algorithm is between 95-100% for microarray images with coefficient of variation less than two.
Experimental results show that the method is capable of gridding microarray images with irregular spots,
varying surface intensity distribution and with more than 50% contamination
Description:
Computer Engineering and Intelligent Systems,Vol.4, No.1, 2013
New dielectric ceramics with formula BaTi3Nb4, O„ and Ba6Til4Nbz039 have been prepared and characterized. BaTi3Nba017 was densified to 92% of TD after firing at 1310 oC for 4 h. However, Ba6Ti 1 4Nb2O39 fired under optimized conditions (1260 ` C for 4 h) showed only 85% TD together with secondary phase. The crystal system of both of the compositions is orthorhombic
Monz, Cabrera J; Diaz, Morcillo A; Pedreno, Molina L; Sanchez, Hermandez D(Microwave and Optical Technology Letters, February 4, 2004)
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Abstract:
Usage of a dielectric multilayer around a dielectric Sample
is studied as a means for improving the efficiency in multimode microwave-
heating cavities. The results show that by using additional dielectric
constant layers the appearance of undesired reflections at the
sample-air interface is avoided and higher power -absorption rates
within the sample and high -efficiency designs are obtained
Binu, Paul; Mridula, S; Aanandan,C K; Mohanan, P(Microwave Engineering Group,Department of Electronics, May 20, 2002)
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Abstract:
compact multihand planar octagonal-shaped microstrip
antenna simultaneously suitable for mobile communication and blue
tooth application is presented. The antenna provides sufficient isolation
benveen the two operating bands and an area reduction of -29 % with
respect to a circular patch operating in the same band
Stephen,D S; Mathew,T; Jose,K A; Aanandan,C K; Mohanan, P; K G Nair(Department of Electronics, February , 1993)
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Abstract:
Simultaneous elimination of specular reflection and backscattered
power from a plane metallic surface by simulated
corrugated surfaces of constant period and variable strip
width for TM polarisation is reported. This new configuration
offers almost a ten-fold frequency bandwidth compared
with a regularly spaced strip grating of the same size.
Abdel, Fattah Sheta(Microwave and Optical Technology Letters, April 5, 2001)
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Abstract:
A novel H-shaped patch antenna suitable for wireless and
satellite communications is presented. The new antenna has some advantages
compared to conventional microstrip patch antennas, such as
small size, a fewer number of modes, no harmonic resonance, and the
provision of pure reactive impedances at its harmonics that can result in
increasing the transmitter efficiency. The basic principles and design
procedure are introduced. Two antennas at two different frequencies, 4
and 10 GHz, are designed, fabricated, and measured. The measured
results show a good agreement with the predicted ones
Jack,Wu; Qiu,S N; Shih,I(Microwave and Optical Technology Letters, November 20, 2004)
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Abstract:
Photonic band-gap (PBG) structures are utilized in microwave
components as filters to suppress unwanted signals. In this
work, rectangular perforations were created in the ground plane of a microstrip line to construct a PBG structure. A gold-coated alumina
substrate was utilized to switch or tune the bandstop characteristics of
this structure. It was demonstrated that the bandstop characteristics
were switched off from - 35 to - 1 dB at 16 GHz. Tuning of the bandstop
edge with a shift of 1.5 GHz was also shown
HIV/AIDS is one of the most destructive epidemics in
ever recorded history claims an estimated 2.4 –3.3 million lives every
year. Even though there is no treatment for this pandemic Elisa and
Western Blot tests are the only tests currently available for detecting
HIV/AIDS. This article proposes a new method of detecting HIV/AIDS
based on the measurement of the dielectric properties of blood at the
microwave frequencies. The measurements were made at the S-band of
microwave frequency using rectangular cavity perturbation technique
with the samples of blood from healthy donors as well as from HIV/AIDS patients. An appreciable change is observed in the dielectric properties
of patient samples than with the normal healthy samples and these
measurements were in good agreement with clinical results. This measurement
is an alternative in vitro method of diagnosing HIV/AIDS using microwaves.
In this paper, a multiband antenna using a novel
fractal design is presented. The antenna structure is formed
by inscribing a hexagonal slot within a circle. This base
structure is then scaled and arranged within the hexagon
along its sides without touching the outer structure. The
proposed CPW fed, low profile antenna offers good
performance in the 1.65 – 2.59 GHz, 4.16 – 4.52 GHz and
5.54 – 6.42 GHz bands and is suitable for GSM 1800/1900,
Bluetooth, IMT advanced systems and upper WLAN
applications. The antenna has been fabricated on a substrate
of height 1.6 mm and εr = 4.4 and simulation and
experimental results are found to be in good agreement
Gijo,Augustin; Shynu, S V; Aanandan,C K; Mohanan, P; Vasudevan, K(Microwave and Optical Technology Letters, April 20, 2005)
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Abstract:
An innovative phaseshifterless, wideband, micrustrip
leaky-wave antenna with an electronically steerable dual-pencil-beam
pattern in the H-plane is presented. The log-periodic geometry of the
leaky slots of the antenna results in a wide bandwidth of 25.19%. The
Jan beam can he steered up to 14° over the wide resonating band of the
anteww. The beam is also steerable at a fixed frequency. by reactivelty
loading the slots and a maximum steering angle of about 14° is ohserved.
for different capacitor values with an improved bandwidth of
33 _i%. This concept is studied using passive components but it can be extended to varactors
Qiang,Gao; Yan,Yin; Dun-Bao,Yan; Nai,Chang Yuan(Microwave and Optical Technology Letters, November 5, 2005)
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Abstract:
A navel ultra-thin radar-absorbing material (RAM) using
metanwterials is presented and the absorption performance is examined.
Due to the high-impedance property of the metamalerials. the thickness
of the RAM is about several tenths of the center wavelength of the absorption
band, which is considerably thinner than conventional absorbers.
The absorption bandwidth of the RAM is about several hundred
megahertz
Supriyo,Dey; Aanandan,C K; Mohanan, P; K G Nair(IETE Technical Review, 1993)
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Abstract:
Design, development and experimental observations of a L: band printed dipole antenna is presented.Bandwidth
enhancement is achieved by end-loading or the dipole arms. Using the present technique Impedance bandwidth van be
enhanced up to 50% without degrading the efficiency of the antenna.
A dual port dual polarized octagonal microstrip patch antenna suitable for dual band applications is discussed
theoretically and experimentally. The antenna exhibits good impedance bandwidth, gain and broad radiation patterns.
Parameters predicted by the Conformal Finite Difference Time Domain algorithm show good agreement with the
simulated results and experimental observations
The paper proposes an octagon shaped Microstrip Patch Antenna suitable for
dual band applications. The striking features of this compact, planar antenna are
sufficient isolation between the two operating bands and an area reduction of -
29% in comparison to a conventional circular patch antenna operating in the
same band
Description:
Antennas and Propagation Society International Symposium, 2002. IEEE
Tessamma, Thomas; Dinesh Kumar, V P(Pleiades Publishing, Ltd, 2008)
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Abstract:
This paper reports a novel region-based shape descriptor based on orthogonal Legendre moments.
The preprocessing steps for invariance improvement of the proposed Improved Legendre Moment Descriptor
(ILMD) are discussed. The performance of the ILMD is compared to the MPEG-7 approved region shape
descriptor, angular radial transformation descriptor (ARTD), and the widely used Zernike moment descriptor
(ZMD). Set B of the MPEG-7 CE-1 contour database and all the datasets of the MPEG-7 CE-2 region database
were used for experimental validation. The average normalized modified retrieval rate (ANMRR) and precision-
recall pair were employed for benchmarking the performance of the candidate descriptors. The ILMD has
lower ANMRR values than ARTD for most of the datasets, and ARTD has a lower value compared to ZMD.
This indicates that overall performance of the ILMD is better than that of ARTD and ZMD. This result is confirmed
by the precision-recall test where ILMD was found to have better precision rates for most of the datasets
tested. Besides retrieval accuracy, ILMD is more compact than ARTD and ZMD. The descriptor proposed is
useful as a generic shape descriptor for content-based image retrieval (CBIR) applications
Description:
Pattern Recognition and Image Analysis, 2008, Vol. 18, No. 1, pp. 23–29