Abstract

This work deals with the problem of fault-tolerant communication over networks, some of whose nodes are corrupted by a centralized byzantine adversary. The extant literature’s perspective of the problem of reliable communication, especially in networks whose topology is known, is that of a simple problem to which even some naive solutions (like message-flooding etc.) turn out to be reasonably efficient. In this paper, we give an example of a directed graph and a non threshold adversary structure, which will require every protocol for perfect reliable unicast to transmit exponential number of bits in order to reliably transmit a single bit.

Abstract

In the perfectly secure message transmission (PSMT) problem, two synchronized non-faulty players (or processors), the Sender S and the Receiver R are connected by n wires (each of which facilitates 2-way communication); S has a message, represented by a sequence oft elements from a finite field, that he wishes to send to R; after exchanging messages in phases R should correctly obtain S 's message, while an adversary listening on and actively controlling any set of t (or less) wires should have no information about S 's message. Similarly, in the problem of perfect reliable message transmission (PRMT), the receiver R should correctly obtain S's message, in spite of the adversary actively controlling any set oft (or less) wires.

Abstract

Shortest path computation has always been a subject of study and research in the history of computer science. In this paper we introduce and initiate the study of the problem of finding the shortest path in a privacy preserving manner, in presence of single convex polygonal obstacle. We also propose an efficient, elegant and simple solution for the problem.

Abstract

This paper considers the problem of unicasting in wireless ad hoc networks. Unicasting is the problem of finding a route between a source and a destination and forwarding the message from the source to the destination. In theory, models that have been used oversimplify the problem of route discovery in ad hoc networks. The achievement of this paper is threefold. First we use a more general model in which nodes can have different transmission and interference ranges and we present a new routing algorithm for wireless ad hoc networks that has several nice features. We then combine our algorithm with that of known greedy algorithms to arrive at an average case efficient routing algorithm in the situation that GPS information is available. Finally we show how to schedule unicast traffic between a set of source-destination pairs by providing a proper vertex coloring of the nodes in the wireless ad hoc network. Our coloring algorithm achieves a O(Δ)–coloring that is locally distinct within the 2-hop neighborhood of any node.

Abstract

Urbanization is rapidly increasing all over the world. Past two decades in India many cities have attracted large population. Reasons being the belief of better education health care job/business prospects etc. For meeting the demands of population density many high-rise structures and large public gathering places are emerging in cities. Places where few thousands of people can meet are quite common in major cities. It is due to this reason evacuation at the public gathering places has gained a lot of importance

Abstract

This paper describes the procedure of vulnerability assessment for building structures in AP India. The objective of this paper is to define the building classification and development of damage probability matrix using fragility curve parameters of the building structures in Andhra Pradesh by using the avaiable information in Vulnerability Atlas of India developed by Building Materials and Technology promotion council Govt. of India (BMTPC).

Abstract

Earthquake Problems are not new to the country. We have witnessed several moderate earthquakes in the last two decades causing innumerable property loss and life loss. In order to minimize the loasses. We need to raise the awareness about earthquake resistant design of structures. This can be achieved by spreading the information on hazard vulnerability and risk to concerend people.

Abstract

This paper describes the procedure of vulnerability assessment of structures for site specific peak ground acceleration. The objective of this paper is to define the building classification and development of damage probability matrix which represent the vulnerability of structure. The organization of this paper is as follows. First, the types of the structures are reviewed and a classification of structure based on the available data with Vulnerability Atlas of India is done. Second, the description of methodologies developed under various organizations is studied, adopted and summarized. Third, the theoretical methodology of the vulnerability analysis using fragility curve parameters given by HAZUS and capacity curve generated using SAP2000 for typical structure are presented and performance of structure is calculated by using capacity spectrum method.

Abstract

A document image is composed of a variety of physical entities or regions such as text blocks, lines, words, figures, tables, and background. We could also assign functional or logical labels such as sentences, titles, captions, author names, and addresses to some of these regions. The process of document structure and layout analysis tries to decompose a given document image into its component regions and understand their functional roles and relationships. The processing is carried out in multiple steps, such as preprocessing, page decomposition, structure understanding, etc. We will look into each of these steps in detail in the following sections. Document images are often generated from ph

Abstract

One of the prime challenges in designing a classifier for large-class problems such as Indian language OCRs is the presence of a large similar looking character set. The nature of the character set introduces problems with accuracy and efficiency of the classifier. Hierarchical classifiers such as Binary Hierarchical Decision Trees (BHDTs) using SVMs as component classifiers have been effectively used to tackle such large-class classification problems. The accuracy and efficiency of a BHDT classifier will depend on: i) the accuracy of the component classifiers, ii) the separability of the clusters at each node in a hierarchical classifier, and iii) the balance of the BHDT. We propose methods to tackle each of the above problems in the case of binary character images. We present a new distance measure, which is intuitively suitable when Support Vector Machines are used as component classifiers. We also propose a novel method for balancing the BHDT to improve its efficiency, while maintaining the accuracy. Finally we propose a method to generate overlapping partitions to improve the accuracy of BHDTs. Comparison of the method with other forms of classifier combination techniques such as 1vs1, 1vsRest and Decision Directed Acyclic Graphs shows that the proposed approach is highly efficient, while being comparable with the more expensive techniques in terms of accuracy. The experiments are focused on the problem of Indian language OCR, while the framework is usable for other problems as well