Development and demonstration of an on-board mission planner for helicopters

Mission management tasks can be distributed within a planning hierarchy, where each level of the hierarchy addresses a scope of action, and associated time scale or planning horizon, and requirements for plan generation response time. The current work is focused on the far-field planning subproblem, with a scope and planning horizon encompassing the entire mission and with a response time required to be about two minutes. The far-feld planning problem is posed as a constrained optimization problem and algorithms and structural organizations are proposed for the solution. Algorithms are implemented in a developmental environment, and performance is assessed with respect to optimality and feasibility for the intended application and in comparison with alternative algorithms. This is done for the three major components of far-field planning: goal planning, waypoint path planning, and timeline management. It appears feasible to meet performance requirements on a 10 Mips flyable processor (dedicated to far-field planning) using a heuristically-guided simulated annealing technique for the goal planner, a modified A* search for the waypoint path planner, and a speed scheduling technique developed for this project

Survivability in Time-varying Networks

Time-varying graphs are a useful model for networks with dynamic connectivity such as vehicular networks, yet, despite their great modeling power, many important features of time-varying graphs are still poorly understood. In this paper, we study the survivability properties of time-varying networks against unpredictable interruptions. We first show that the traditional definition of survivability is not effective in time-varying networks, and propose a new survivability framework. To evaluate the survivability of time-varying networks under the new framework, we propose two metrics that are analogous to MaxFlow and MinCut in static networks. We show that some fundamental survivability-related results such as Menger's Theorem only conditionally hold in time-varying networks. Then we analyze the complexity of computing the proposed metrics and develop several approximation algorithms. Finally, we conduct trace-driven simulations to demonstrate the application of our survivability framework to the robust design of a real-world bus communication network

Energy management in communication networks: a journey through modelling and optimization glasses

The widespread proliferation of Internet and wireless applications has produced a significant increase of ICT energy footprint. As a response, in the last five years, significant efforts have been undertaken to include energy-awareness into network management. Several green networking frameworks have been proposed by carefully managing the network routing and the power state of network devices. Even though approaches proposed differ based on network technologies and sleep modes of nodes and interfaces, they all aim at tailoring the active network resources to the varying traffic needs in order to minimize energy consumption. From a modeling point of view, this has several commonalities with classical network design and routing problems, even if with different objectives and in a dynamic context. With most researchers focused on addressing the complex and crucial technological aspects of green networking schemes, there has been so far little attention on understanding the modeling similarities and differences of proposed solutions. This paper fills the gap surveying the literature with optimization modeling glasses, following a tutorial approach that guides through the different components of the models with a unified symbolism. A detailed classification of the previous work based on the modeling issues included is also proposed

Hierarchical Design Based Intrusion Detection System For Wireless Ad hoc Network

In recent years, wireless ad hoc sensor network becomes popular both in civil and military jobs. However, security is one of the significant challenges for sensor network because of their deployment in open and unprotected environment. As cryptographic mechanism is not enough to protect sensor network from external attacks, intrusion detection system needs to be introduced. Though intrusion prevention mechanism is one of the major and efficient methods against attacks, but there might be some attacks for which prevention method is not known. Besides preventing the system from some known attacks, intrusion detection system gather necessary information related to attack technique and help in the development of intrusion prevention system. In addition to reviewing the present attacks available in wireless sensor network this paper examines the current efforts to intrusion detection system against wireless sensor network. In this paper we propose a hierarchical architectural design based intrusion detection system that fits the current demands and restrictions of wireless ad hoc sensor network. In this proposed intrusion detection system architecture we followed clustering mechanism to build a four level hierarchical network which enhances network scalability to large geographical area and use both anomaly and misuse detection techniques for intrusion detection. We introduce policy based detection mechanism as well as intrusion response together with GSM cell concept for intrusion detection architecture.Comment: 16 pages, International Journal of Network Security & Its Applications (IJNSA), Vol.2, No.3, July 2010. arXiv admin note: text overlap with arXiv:1111.1933 by other author

A database management capability for Ada

The data requirements of mission critical defense systems have been increasing dramatically. Command and control, intelligence, logistics, and even weapons systems are being required to integrate, process, and share ever increasing volumes of information. To meet this need, systems are now being specified that incorporate data base management subsystems for handling storage and retrieval of information. It is expected that a large number of the next generation of mission critical systems will contain embedded data base management systems. Since the use of Ada has been mandated for most of these systems, it is important to address the issues of providing data base management capabilities that can be closely coupled with Ada. A comprehensive distributed data base management project has been investigated. The key deliverables of this project are three closely related prototype systems implemented in Ada. These three systems are discussed

AGENT-BASED UNDER HOOD PACKING

Improving vehicle performance and passenger comfort has been a prime engineering concern and focus of research for many years in automotive design. Turning to high-performance components in an effort to improve vehicle performance alone is often not enough and their placement and interactions with other components should also be an integral part of the improvement process. With the advancement in hybrid electric vehicle technology, the packing of components under the hood is ever more essential and challenging. Under hood packing is a multi-objective optimization problem with many, and mostly conflicting objectives. A non-deterministic multi-objective evolutionary algorithm needs to be integrated with the packing algorithm to obtain solutions. However, it is almost impossible to find optimal solutions in a limited amount of time due to the computationally intensive algorithm. Therefore, a new and efficient approach needs to be developed. This study applies an agent-based approach to the under hood vehicle packing problem with three objectives, namely: center of gravity, survivability, and maintainability subject to no overlap among components and with the enclosure, and minimum ground clearance. As per the weak notion of agency, a layered architecture is built with an agent on top of object model. A non-deterministic evolutionary multi-objective algorithm (AMGA-2) is used to identify non-dominated solutions, speed up the convergence to a non-dominated set and prevents unpredictability in the agent system. The developed agent-based model is applied to a passenger car but, it can also address large packing problems for SUVs and Trucks (FMTV). This work demonstrates the applicability and benefits of an agent-based approach to the packing problem

Towards an evaluation framework for medical web applications

Copyright @ 2013 EMCIS.The main aim of this study is to review and analyse various evaluation frameworks used to assess the operational effectiveness of various Information Technology (IT) processes/applications and identify their strengths in order to form a new holistic framework for economic evaluation of web applications. This research aims to address the need for a new holistic evaluation framework for the purpose of the evaluation of the medical web applications. Over the last decade more and more, companies used accountancy techniques such as the frameworks analysed in this research. This new holistic framework that was developed will include also steps regarding the indirect and intangible costs and benefits identification and their incorporation in the evaluation process. Moreover the new emerging market of the medical websites and the embedded on them web applications requires also a new evaluation framework that will provide accurate results in the estimation of the efficiency of an investment on them. The paper first presents an introduction about why economic evaluation is important when evaluating the Information Technology in organizations. Various studies are reviewed, which highlight the ever increasing importance of integrating economic evaluation processes, such as Cost Benefit Analysis (CBA) and Return on Investment (ROI), into systems and processes of organizations and economic organizations, and analyse the factors that govern their role. Finally, the evaluation frameworks and methods that are found in these studies should be used as a part of a proactive systematic action plan that the organizations could use to avoid budget reduction due to incorrect planning. The next part of this study includes a comprehensive presentation and review of past frameworks used to evaluate Information Technology. The frameworks that are reviewed are the Framework for evaluation of information systems, the Information Technology Adoption Model (ITAM), the Total Evaluation and Acceptance Methodology (TEAM) framework, the ROI Process Model and HOT-fit evaluation framework for Health Information Systems