Heritage Institute of Technology

About: Heritage Institute of Technology is a based out in . It is known for research contribution in the topics: Support vector machine & Transconductance. The organization has 581 authors who have published 1045 publications receiving 8345 citations.

Modeling of Wide-Band Optical Signal Amplification in an EDFA Network Using Tunable Tap

Abstract: Optical amplification in C and L band region with wave division multiplexing can provide over 160 channels. The paper provides simulation studies of such a wideband erbium doped fiber amplifier which utilizes a tunable tap at the TLS source end. This isolates and provides two parallel channels for simultaneous amplification in both C and L band. Such a configuration has shown to provide a gain well over 20dB from 1525-1615nm bandwidth with average noise figure of 10dB (approx.). Gain saturation effects beyond -20dBm/channel signal level and, gain spectra at different pump powers and amplifier lengths have also been studied. Full Text: PDF References Robert E. Tench, Proc. IEEE Elecronic Componenets and Technology Conference. 9, (1999). J. F. Massicott, R. Wyatt, and B. J. Ainslie, "Low noise operation of Er 3+ doped silica fibre amplifier around 1.6 ?m", Electron. Lett. 28, 1924 (1992). CrossRef Y. Sun, A. Srivastava, J.Zhou, and J. Sulhoff, "Optical fiber amplifiers for WDM optical networks", Bell Labs Technical Journal. 4, (1999) CrossRef H. Ono, M. Yamada and Y. Ohishi, "Gain-flattened Er/sup 3+/-doped fiber amplifier for a WDM signal in the 1.57-1.60-?m wavelength region", IEEE Photon. Technol. Lett. 9, (1997). CrossRef C. Jiang, W. Hu, Q. Zeng and S. Xiao, "High detectivity GaInAs-InP quantum-well infrared photodetectors grown on Si substrates", IEEE Photon. Technol. Lett. 14, 290 (2002). CrossRef M. A. Mahdi, F. R. M. Adikan, P. Poopalan, S. Selvakennedy, W. Y. Chan, and H. Ahmad, "Long-wavelength EDFA gain enhancement through 1550 nm band signal injection", Opt. Commnun.175, 296 (2000). CrossRef H. Chen, M. Leblanc and G.W. Schinn, "Gain enhanced L-band optical fiber amplifiers and tunable fiber lasers with erbium-doped fibers", Opt. Comm. 216, 119 (2003). CrossRef M. A. Mahdi and H. Ahmad, "Gain enhanced L-band Er/sup 3+/-doped fiber amplifier utilizing unwanted backward ASE", IEEE Photon. Technol. Lett. 13, 1067 (2001). CrossRef S. W. Harun, N. Tamchek, P. Poopalan and H. Ahmad, "Gain clamping in two-stage L-band EDFA using a broadband FBG", IEEE Photon. Technol. Lett. 16, 422 (2004). CrossRef T. Sakamoto. "Wide wavelength band (1535?1560 nm and 1574?1600 nm), 28 × 10 Gbit/s WDM transmission over 320 km dispersion-shifted fibre", Electron. Lett.34, 392 (1998). CrossRef Y. Sun et al., "80 nm ultra-wideband erbium-doped silica fibre amplifier", Electron. Lett. 33,1965 (1997). CrossRef T. Kasamatsu, Y. Tano and T. Ono, 13, 31 (2001). S. K. Liaw and Y. K. Chen, "Self-phase modulation coefficient of multiple-quantum-well optical amplifiers", IEEE Photon. Tech. Lett. 8, 876 (1996). CrossRef A. Srivastava and Y. Sun, Optical Fiber Telecommunications, I. P. Kaminov and T. Li, Eds. (San Diego, CA: Academic 2002, vol. VI A). R. Anthony and S.N. Biswas, "Temperature Dependent Gain Analysis of a Cascaded C-Band EDFA DWDM Network", Elseviers Procedia Technol. 4, 92 (2012). CrossRef G. Luo, J. L. Zyskind, I. A. Nagel, and M. A. Ali, "Experimental and theoretical analysis of relaxation-oscillations and spectral hole burning effects in all-optical gain-clamped EDFA's for WDM networks", IEEE J. Lightwave Technol. 16, 527 (1998). CrossRef I.K. Bu Sohn and J.W. Song, "Gain flattened and improved double-pass two-stage EDFA using microbending long-period fiber gratings", Optical Communications. 236, 141 (2004). CrossRef R. Singh, Sunanda and E.K. Sharma, "Gain flattening by long period gratings in erbium doped fibers", Optical Communications. 240, 123 (2004). CrossRef

A group-based multilayer encryption scheme for secure dissemination of post-disaster situational data using peer-to-peer delay tolerant network

Abstract: In the event of a disaster, the communication infrastructure can be partially or totally destroyed, or rendered unavailable due to high congestion. Today's smart-phones that can communicate directly via Bluetooth or WiFi without using any network infrastructure, can be used to create an opportunistic post disaster communication network where situational data can spread quickly, even in the harshest conditions. However, presence of malicious and unscrupulous entities that forward sensitive situational data in such a network may pose serious threats on accuracy and timeliness of the data. Therefore, providing basic security features, like authentication, confidentiality and integrity, to all communications occurring in this network becomes inevitable. But, in such an opportunistic network, that uses short range and sporadic wireless connections, no trusted third party can be used as it won't be accessible locally at the runtime. As a result, traditional security services like cryptographic signatures, certificates, authentication protocols and end-to-end encryption become inapplicable. Moreover, since disaster management is generally a group based activity; a forwarding entity may be better authenticated based on its group membership verification. In this paper, we propose a Group-based Distributed Authentication Mechanism that enables nodes to mutually authenticate each other as members of valid groups and also suggest a Multilayer Hashed Encryption Scheme in which rescue-groups collaboratively contribute towards preserving the confidentiality and integrity of sensitive situational information. The schemes provide authentication, confidentiality and integrity in a fully decentralized manner to suit the requirements of an opportunistic post disaster communication network. We emulate a post disaster scenario in the ONE simulator to show the effectiveness of our schemes in terms of delivery ratio, average delay and overhead ratio.

Predictive Diagnosis of Glaucoma Based on Analysis of Focal Notching along the Neuro-Retinal Rim Using Machine Learning

Abstract: Automatic evaluation of the retinal fundus image is regarded as one of the most important future tools for early detection and treatment of progressive eye diseases like glaucoma. Glaucoma leads to progressive degeneration of vision which is characterized by shape deformation of the optic cup associated with focal notching, wherein the degeneration of the blood vessels results in the formation of a notch along the neuroretinal rim. In this study, we have developed a methodology for automated prediction of glaucoma based on feature analysis of the focal notching along the neuroretinal rim and cup to disc ratio values. This procedure has three phases: the first phase segments the optic disc and cup by suppressing the blood vessels with dynamic thresholding; the second phase computes the neuroretinal rim width to detect the presence and direction of notching by the conventional ISNT rule apart from calculating the cup-to-disc ratio from the color fundus image (CFI); the third phase uses linear support vector based machine learning algorithm by integrating extracted parameters as features for classification of CFIs into glaucomatous or normal. The algorithm outputs have been evaluated on a freely available database of 101 images, each marked with decision of five glaucoma expert ophthalmologists, thereby returning an accuracy rate of 87.128%.

On Invex Functions in Hilbert Space

Abstract: In this paper invex functions have been introduced in Hilbert space. Some important results regarding the characterization of such functions have been discussed. It has been proved that although being a generalization of the class of convex functions, this class of functions posses some properties which are not true in case of the class of convex functions in general.

Image steganography by closest pixel-pair mapping

Abstract: Steganography is one of the important and elegant tools used to securely transfer secret message in an imperceptible manner. Visual Steganography is another added feature of it. It is the steganographic method involving multimedia files like image, video etc. to hide a secret message. However this method may result in the distortion of the colour frequencies of the cover image which is predictable by some analysis. Here in this paper we have proposed a method for steganography which results in absolutely no distortion of the cover image. The proposed image is independent of the size of the cover image and the secret image i.e. a larger image can be hidden in a smaller image. The proposed method also uses AES Encryption for secure transfer of the stego-key. The nexus of this cover image and the encrypted data serves the purpose of secure transfer of secret data.