Reliability of a Gaussian channel in the presence of Gaussian feedback

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (leaves 29-30).The communication reliability, or error exponent, of a continuous time, infinite band-width, Additive White Gaussian Noise channel was studied under a peak power constraint, in the presence of a feedback channel that was also a continuous time peak-power constrained infinite bandwidth Additive White Gaussian Noise channel. Motivated by [9], a two phase scheme was studied, where, in the first phase, the Encoder transmits the message in small bit-packets and the Decoder then informs the Encoder of the decoded message. With this knowledge, in the second phase, the Encoder sends a confirm or deny signal to the Decoder and the Decoder then informs the Encoder of its final action. In the first phase, the Encoder uses an orthogonal signalling scheme and the Decoder uses a deterministic Identification code. In the second phase, the Encoder uses antipodal signalling, while the Decoder utilizes a sequential semi-orthogonal peak-power constrained anytime code. To improve the reliability of the anytime code, additional messages are pipelined into the forward channel by the Encoder once it finishes its phase two transmission, before receiving the Decoder's phase two transmission.(cont.) Using this scheme, the following lower bound on the reliability of this channel is obtained: where 4R is the average rate of data transmission and C are the capacities of where R is the average rate of data transmission and Ci and 02 are the capacities of the forward and reverse channels respectively. To achieve this reliability, the capacity of the reverse channel, C2 must be greater than the forward capacity C1.by Aman Chawla.S.M

Managing Class II Malocclusion Using Twin Block Therapy in a Young Adolescent Female: A Case Report

Twin block therapy is highly effective in patients with remaining growth potential. However, its successful use is confounded by many patient related factors such as age, gender, compliance of the patient and other miscellaneous criteria’s. If treated within time, growth modification and orthopedics can harness suitable forces to cause skeletal correction of the malocclusion. The appliance is highly successful in a patient with retruded mandible and presenting with a positive visual treatment objective. This paper discusses a case of 11-year-old female patient with characteristic twin block appliance indication in which successful skeletal modification was achieved

Short term outcome and predictors of response to neoadjuvant treatment in rectal cancer

Abstract OBJECTIVE: To evaluate response to neoadjuvant chemoradiation in the treatment of rectal cancer and to see if it can be predicted whether a particular patient will benefit from such treatment. METHODS: The retrospective case series was done at the Aga Khan University Hospital, Karachi, and comprised data related to period from January 2005 to December 2014 of patients with rectal cancer who had received neoadjuvant treatment. They were divided into responders and non-responders on the basis of imaging. Pre-treatment factors were compared to identify differences in the two groups. SPSS 19 was used for statistical analysis. RESULTS: The median age of 35 patients whose records were studied was 44 years (interquartile range: 33-54). Response to neoadjuvant treatment was seen in 13(37%) patients with complete pathological response in 8(22.9%). There was no statistically significant difference in age, gender, pre-treatment tumour stage, tumour biology and distance from anal verge among the responders and the non-responders (p\u3e0.05 each)

Integrating Web - based Services with Distributed Computing over a Network

Past few decades has been years of revolution especially in Information Technology. Because of its omnipresent nature, evolution has taken place from standalone applications to web based applications to distributed computing. Combining interrelated features of IT gave rise to services using Distributed Computing over a network also known as Cloud Computing. Cloud computing is basically internet computing, where the data is stored, accessed and processed on remote servers via internet. This electronic document focuses on integration of web service with cloud, which gives an essence of SaaS aspect of Cloud computing. This also describes the case study to attempt an implementation of the same. DOI: 10.17762/ijritcc2321-8169.150518

Face Recognition by Artificial Neural Network using MATLAB Toolbox

Technology has always aimed at making human life easier and Artificial Neural Network has played an integral part in achieving this. Neural networks include simple elements operating in parallel which are inspired by biological nervous systems. These networks can be trained to perform specific task which is remedy for the problems faced by conventional computers or human beings. This electronic document mainly focuses on implementation of face recognition software which uses Neural Network tool box of MATLAB with back propagation algorithm. This software recognizes faces from standard set of images and also calculates error probability. DOI: 10.17762/ijritcc2321-8169.150615

Universal quantum computation using single qubit discrete-time quantum walk

Universal quantum computation can be realised using both continuous-time and discrete-time quantum walks. We present a version based on single qubit discrete-time quantum walk to realize multi-qubit computation tasks. The scalability of the scheme is demonstrated by using a set of walk operations on a closed lattice form to implement the universal set of quantum gates on multi-qubit system. We also present a set of experimentally realizable walk operations that can implement Grover's algorithm, quantum Fourier transformation and quantum phase estimation algorithms. Analysis of space and time complexity of the scheme highlights the advantages of quantum walk based model for quantum computation on systems where implementation of quantum walk evolution operations is inherent feature of the system.Comment: 16 papges, 16 figure

Wearables in medicine

Wearables as medical technologies are becoming an integral part of personal analytics, measuring physical status, recording physiological parameters, or informing schedule for medication. These continuously evolving technology platforms do not only promise to help people pursue a healthier life style, but also provide continuous medical data for actively tracking metabolic status, diagnosis, and treatment. Advances in the miniaturization of flexible electronics, electrochemical biosensors, microfluidics, and artificial intelligence algorithms have led to wearable devices that can generate real-time medical data within the Internet of things. These flexible devices can be configured to make conformal contact with epidermal, ocular, intracochlear, and dental interfaces to collect biochemical or electrophysiological signals. This article discusses consumer trends in wearable electronics, commercial and emerging devices, and fabrication methods. It also reviews real-time monitoring of vital signs using biosensors, stimuli-responsive materials for drug delivery, and closed-loop theranostic systems. It covers future challenges in augmented, virtual, and mixed reality, communication modes, energy management, displays, conformity, and data safety. The development of patient-oriented wearable technologies and their incorporation in randomized clinical trials will facilitate the design of safe and effective approaches

On Axon-Axon Interaction via Currents and Fields

In this dissertation, we investigate coupling between axons in a tract, when the tract has an arbitrary cross-section, with the coupling being mediated by currents as well as electric fields. Under the current mediated setting, we develop a new master equation which captures the relative axonal geometry, specifically, the axon inclinations θi and the inter-axon distances Wip and perform a number of simulations. We observe synchronization in our simulations of axons with differing diameters and separation-dependent coupling delays in the case of non-trivial tract geometries. For the field-mediated interaction setting, we determine the electric near-field of a firing axon’s node of Ranvier - its strength and direction - by a volume conduction approach as well as a more microscopic, dipole-based approach. We obtain field strengths of about 105V/m at a few hundred micron distance from the source at the node. With the field levels having been found significant enough to cause 100 mV voltage drops across 1 micron-diameter axons, we develop an alternate, field-mediated model for synchronization between axons based on the dipole fields generated during action potential propagation. This model shows that synchronization between action potentials on differing axons depends on the phases of the synchronizing action potentials and not merely their separation. Since synchronization takes place in both settings, but currents are generated by fields, when constrained to a specific direction, we find that the field picture is a generalization of the presently prevalent current mediated picture for interaction between axons