Abstract: | Propagation of electromagnetic waves through a microstrip line with 2D electromagnetic baud gap (EBG) structures of different geometrical shapes in the ground plane is investigated in this paper. Using transmission-line theory, the design equations for EBG structures are calculated. The measured, numerical. and simulated results are in gone) agreement |
URI: | http://dyuthi.cusat.ac.in/purl/1422 |
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Design and anal ... ent geometrical shapes.PDF | (923.1Kb) |
Abstract: | This paper presents the optimal design of a sur- face mounted permanent magnet Brushless DC mo- tor (PMBLDC) meant for spacecraft applications. The spacecraft applications requires the choice of a torques motor with high torque density, minimum cogging torque, better positional stability and high torque to inertia ratio. Performance of two types of machine con¯gurations viz Slotted PMBLDC and Slotless PMBLDC with halbach array are compared with the help of analytical and FE methods. It is found that unlike a Slotted PMBLDC motor, the Slotless type with halbach array develops zero cogging torque without reduction in the developed torque. Moreover, the machine being coreless provides high torque to inertia ratio and zero magnetic stiction |
Description: | ECTI TRANSACTIONS ON ELECTRICAL ENG., ELECTRONICS, AND COMMUNICATIONS VOL.9, NO.1 February 2011 |
URI: | http://dyuthi.cusat.ac.in/purl/4483 |
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Design and Anal ... pacecraft Applications.pdf | (479.3Kb) |
Abstract: | This paper presents the design and development of a frame based approach for speech to sign language machine translation system in the domain of railways and banking. This work aims to utilize the capability of Artificial intelligence for the improvement of physically challenged, deaf-mute people. Our work concentrates on the sign language used by the deaf community of Indian subcontinent which is called Indian Sign Language (ISL). Input to the system is the clerk’s speech and the output of this system is a 3D virtual human character playing the signs for the uttered phrases. The system builds up 3D animation from pre-recorded motion capture data. Our work proposes to build a Malayalam to ISL |
Description: | 2009 World Congress on Nature & Biologically Inspired Computing (NaBIC 2009) |
URI: | http://dyuthi.cusat.ac.in/purl/4091 |
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Design and Deve ... tem for English-to-ISL.pdf | (299.6Kb) |
Abstract: | The design and development of a cost-effective, simple, sensitive and portable LED based fiber optic evanescent wave sensor for simultaneously detecting trace amounts of chromium and nitrite in water are presented. In order to obtain the desired performance, the middle portions of two multimode plastic clad silica fibers are unclad and are used as the sensing elements in the two arms of the sensor. Each of the sensor arms is sourced by separate super bright green LEDs, which are modulated in a time-sharing manner and a single photo detector is employed for detecting these light signals. The performance and characteristics of this system clearly establish the usefulness of the technique for detecting very low concentrations of the dissolved contaminants. |
URI: | http://dyuthi.cusat.ac.in/purl/2594 |
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Dyuthi-P0154.pdf | (176.0Kb) |
Abstract: | For the scientific and commercial utilization of Ocean resources, the role of intelligent underwater robotic systems are of great importance. Scientific activities like Marine Bio-technology, Hydrographic mapping, and commercial applications like Marine mining, Ocean energy, fishing, aquaculture, cable laying and pipe lining are a few utilization of ocean resources. As most of the deep undersea exploration are beyond the reachability of divers and also as the use of operator controlled and teleoperated Remotely Operated Vehicles (ROVs) and Diver Transport Vehicles (DTVs) turn out to be highly inefficient, it is essential to have a fully automated system capable providing stable control and communication links for the unstructured undersea environment. |
Description: | OCEANS 2003. Proceedings,VOL 1 |
URI: | http://dyuthi.cusat.ac.in/purl/4477 |
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Design and Deve ... Manipulator Controller.pdf | (74.67Kb) |
Abstract: | This paper presents the design and analysis of a 400-step hybrid stepper motor for spacecraft applications. The design of the hybrid stepper motor for achieving a specific performance requires the choice of appropriate tooth geometry. In this paper, a detailed account of the results of two-dimensional finite-element (FE) analysis conducted with different tooth shapes such as square and trapezoidal, is presented. The use of % more corresponding increase in detent torque and distorted static torque profile. For the requirements of maximum torque density, less-detent torque, and better positional accuracy and smooth static torque profile, different pitch slotting with equal tooth width has to be provided. From the various FE models subjected to analysis trapezoidal teeth configuration with unequal tooth pitch on the stator and rotor is found to be the best configuration and is selected for fabrication. The designed motor is fabricated and the experimental results is compared with the FE results |
Description: | Electric Machines and Drives Conference, 2009. IEMDC'09. IEEE International |
URI: | http://dyuthi.cusat.ac.in/purl/4485 |
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Design and Fini ... pacecraft Applications.pdf | (566.7Kb) |
Abstract: | In order to minimize the risk of failures or major renewals of hull structures during the ship's expected life span, it is imperative that the precaution must be taken with regard to an adequate margin of safety against any one or combination of failure modes including excessive yielding, buckling, brittle fracture, fatigue and corrosion. The most efficient system for combating underwater corrosion is 'cathodic protection'. The basic principle of this method is that the ship's structure is made cathodic, i.e. the anodic (corrosion) reactions are suppressed by the application of an opposing current and the ship is there by protected. This paper deals with state of art in cathodic protection and its programming in ship structure |
Description: | International Journal of Chemical Engineering and Applications, Vol. 1, No. 3, October 2010 |
URI: | http://dyuthi.cusat.ac.in/purl/4672 |
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Design and Prog ... c Protection For Ships.pdf | (322.2Kb) |
Abstract: | The design, erection and evalution procedures for it microwave anechuic chamber competed at Cochin University for antenna studies are presented the chamber has an average reflectivity level of - 32 dB on at X-band frequencies, and it i, comparable to international standards. |
URI: | http://dyuthi.cusat.ac.in/purl/1434 |
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Design,developm ... rowave antenna studies.PDF | (1.493Mb) |
Abstract: | In this paper the design issues of compact genetic microstrip antennas for mobile applications has been investigated. The antennas designed using Genetic Algorithms (GA) have an arbitrary shape and occupies less area (compact) compared to the traditionally designed antenna for the same frequency but with poor performance. An attempt has been made to improve the performance of the genetic microstrip antenna by optimizing the ground plane (GP) to have a fish bone like structure. The genetic antenna with the GP optimized is even better compared to the traditional and the genetic antenna. |
Description: | Antennas and Propagation Society International Symposium, 2008. AP-S 2008. IEEE |
URI: | http://dyuthi.cusat.ac.in/purl/4346 |
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Design of a Com ... Antenna with improved.pdf | (395.7Kb) |
Abstract: | A compact microstrip multiband antenna on a modified ground plane which can operate over the bands starting from 900 MHz to 5.35 GHz which includes the GSM (880-960) GPS (1568-1592 MHz), DCS (1710-1880 MHz), and PCS (1850- 1990 MHz). UMTS (1920-2170 MHz), IEEE 802.11 b/g (2400- 2484) and WLAN IEEE 802.11a band (5.15-5.35) is reported in this paper. The overall dimension of the antenna is 33 x 33 mm2 including the top patch with a dimension 22 x 22 mm2. The experimental results of the antenna are presented in this paper. The results confirm that the antenna exhibits wide band characteristics and covers 7 bands of operation |
Description: | India Conference (INDICON), 2009 Annual IEEE |
URI: | http://dyuthi.cusat.ac.in/purl/4324 |
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Design of a Com ... and Microstrip Antenna.pdf | (161.8Kb) |
Abstract: | The design and performance of a stepped slot printed monopole antenna in the ultrawideband is presented in this article. Multiple resonances generated by the stepped slot geometry are matched in the ultrawideband using a modified microstrip feed. The impedance bandwidth (SWR < 2) of the antenna is from 3 to 11 GHz. Radiation patterns are stable and omnidirectional with appreciable gain throughout the band. Performance of the antenna is also analyzed in the time domain, which reveals good pulse handling capabilities. Compact geometry of the antenna allows easy commercial deployment. |
URI: | http://dyuthi.cusat.ac.in/purl/2711 |
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Dyuthi-P00351.pdf | (388.8Kb) |
Abstract: | Electric permittivity and magnetic permeability control electromagnetic wave propagation th rough materials. I n naturally occu rring materials, these are positive. Artificial materials exhi b iting negative material properties have been reported : they are referred to as metamaterials. This paper concentrates on a ring-type split-ring resonator (SRR) exhibiting negative magnetic permeability. The design and synthesis of the SRR using the genetic-algorithm approach is explained in detail. A user-friendly g raphical user i nterface (G U I ) for an SRR optim izer and estimator using MATLAB TM is also presented |
Description: | IEEE Antennas and Propagation Magazine, Vol. 53, No. 4, August 20 1 1 |
URI: | http://dyuthi.cusat.ac.in/purl/4322 |
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Design of an ... g Split-ring resonator.pdf | (4.797Mb) |
Abstract: | A method for simultaneously enhancing the bandwidth and reducing the size of microstrip antennas (MSAs) using a modified ground plane (GP) has been proposed with design formulas. A combshaped truncated GP is used for this purpose. This method provides an overall compactness up to 85% for proximity-coupled MSAs in the frequency range of 900 MHz–5.5 GHz with an improvement inbandwidth up to seven times when compared with the conventional ones |
Description: | MICROWAVE AND OPTICAL TECHNOLOGY LETTERS / Vol. 52, No. 12, December 2010 |
URI: | http://dyuthi.cusat.ac.in/purl/4343 |
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Design Of Compa ... Modified Ground Plane.pdf | (1.142Mb) |
Abstract: | The design of a compact, single feed, dual frequency dual polarized and electronically reconfigurable microstrip antenna is presented in this paper. A square patch loaded with a hexagonal slot having extended slot arms constitutes the fundamental structure of the antenna. The tuning of the two resonant frequencies is realized by varying the effective electrical length of the slot arms by embedding varactor diodes across the slots. A high tuning range of 34.43% (1.037–1.394 GHz) and 9.27% (1.359–1.485 GHz) is achieved for the two operating frequencies respectively, when the bias voltage is varied from 0 to −30 V. The salient feature of this design is that it uses no matching networks even though the resonant frequencies are tuned in a wide range with good matching below −10 dB. The antenna has an added advantage of size reduction up to 80.11% and 65.69% for the two operating frequencies compared to conventional rectangular patches. |
URI: | http://dyuthi.cusat.ac.in/purl/2733 |
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Dyuthi-P00367.pdf | (179.9Kb) |
Abstract: | Here we investigate the diversity of pathogenic Vibrio species in marine environments close to Suva, Fiji. We use four distinct yet complementary analyses – biochemical testing, phylogenetic analyses, metagenomic analyses and molecular typing – to provide some preliminary insights into the diversity of vibrios in this region. Taken together our analyses confirmed the presence of nine Vibrio species, including three of the most important disease-causing vibrios (i.e. V. cholerae, V. parahaemolyticus and V. vulnificus), in Fijian marine environments. Furthermore, since toxigenic V. parahaemolyticus are present on fish for consumption we suggest these bacteria represent a potential public health risk. Our results from Illumina short read sequencing are encouraging in the context of microbial profiling and biomonitoring. They suggest this approach may offer an efficient and costeffective method for studying the dynamics of microbial diversity in marine environments over time. |
Description: | Environmental Microbiology Reports (2012) 4(4), 403–411 |
URI: | http://dyuthi.cusat.ac.in/purl/3946 |
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Detection and d ... genic Vibrio from Fiji.pdf | (740.7Kb) |
Abstract: | This article reports a new in vitro bile analysis based on the measurement of the dielectric properties at microwave frequencies. The measurements were made using rectangular cavity perturbation technique at the S-band of microwave frequency with the different samples of bile obtained from healthy persons as well as from patients. It is observed that an appreciable change in the dielectric properties of patient’s samples with the normal healthy samples and these measurements were in good agreement with clinical analysis. These results prove an alternative in-vitro method of detecting bile abnormalities based on the measurement of the dielectric properties of bile samples using microwaves without surgical procedure. |
URI: | http://dyuthi.cusat.ac.in/xmlui/purl/2049 |
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Detection of biliary functional...pdf | (162.2Kb) |
URI: | http://dyuthi.cusat.ac.in/purl/2732 |
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Dyuthi-P00366.pdf | (129.9Kb) |
Abstract: | In this paper, moving flock patterns are mined from spatio- temporal datasets by incorporating a clustering algorithm. A flock is defined as the set of data that move together for a certain continuous amount of time. Finding out moving flock patterns using clustering algorithms is a potential method to find out frequent patterns of movement in large trajectory datasets. In this approach, SPatial clusteRing algoRithm thrOugh sWarm intelligence (SPARROW) is the clustering algorithm used. The advantage of using SPARROW algorithm is that it can effectively discover clusters of widely varying sizes and shapes from large databases. Variations of the proposed method are addressed and also the experimental results show that the problem of scalability and duplicate pattern formation is addressed. This method also reduces the number of patterns produced |
Description: | 2012 International Conference on Data Science & Engineering (ICDSE) |
URI: | http://dyuthi.cusat.ac.in/purl/4107 |
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Detection of Fl ... niques - an Experience.pdf | (284.4Kb) |
Abstract: | A method for computer- aided diagnosis of micro calcification clusters in mammograms images presented . Micro calcification clus.eni which are an early sign of bread cancer appear as isolated bright spots in mammograms. Therefore they correspond to local maxima of the image. The local maxima of the image is lint detected and they are ranked according to it higher-order statistical test performed over the sub band domain data |
URI: | http://dyuthi.cusat.ac.in/purl/1355 |
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Detection of mi ... let transform analysis.PDF | (411.8Kb) |
Abstract: | Bacillus smithii BTMS 11, isolated from marine sediment, produced alkaline and thermostable lipase. The enzyme was purified to homogeneity by ammonium sulfate precipitation and ion exchange chromatography which resulted in 0.51 % final yield and a 4.33 fold of purification. The purified enzyme was found to have a specific activity of 360 IU/mg protein. SDS-PAGE analyses, under non-reducing and reducing conditions, yielded a single band of 45 kDa indicating the single polypeptide nature of the enzyme and zymogram analysis using methylumbelliferyl butyrate as substrate confirmed the lipolytic activity of the protein band. The enzyme was found to have 50 C and pH 8.0 as optimum conditions for maximal activity. However, the enzyme was active over wide range of temperatures (30–80 C) and pH (7.0–10.0). Effect of a number of metal salts, solvents, surfactants, and other typical enzyme inhibitors on lipase activity was studied to determine the novel characteristics of the enzyme. More than 90 % of the enzyme activity was observed even after 3 h of incubation in the presence of commercial detergents Surf, Sunlight, Ariel, Henko, Tide and Ujala indicating the detergent compatibility of B. smithii lipase. The enzyme was also found to be efficient in stain removal from cotton cloths. Further it was observed that the enzyme could catalyse ester synthesis between fatty acids of varying carbon chain lengths and methanol with high preference for medium to long chain fatty acids showing 70 % of esterification. Results of the study indicated scope for application of this marine bacterial lipase in various industries |
Description: | World J Microbiol Biotechnol (2013) 29:1349–1360 DOI 10.1007/s11274-013-1298-0 |
URI: | http://dyuthi.cusat.ac.in/purl/4262 |
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Detergent compa ... cillus smithii BTMS 11.pdf | (531.4Kb) |
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