GPS-free Positioning in Mobile Ad-Hoc Networks

In this paper we consider the problem of node positioning in ad-hoc networks. We propose a distributed, infrastructure-free positioning algorithm that does not rely on Global Positioning System (GPS). The algorithm uses the distances between the nodes to build a relative coordinate system in which the node positions are computed in two dimensions. The main contribution of this work is to define and compute relative positions of the nodes in an ad-hoc network without using GPS. We further explain how the proposed approach can be applied to wide area ad-hoc networks

Modelling public transport accessibility with Monte Carlo stochastic simulations: A case study of Ostrava

Activity-based micro-scale simulation models for transport modelling provide better evaluations of public transport accessibility, enabling researchers to overcome the shortage of reliable real-world data. Current simulation systems face simplifications of personal behaviour, zonal patterns, non-optimisation of public transport trips (choice of the fastest option only), and do not work with real targets and their characteristics. The new TRAMsim system uses a Monte Carlo approach, which evaluates all possible public transport and walking origin-destination (O-D) trips for k-nearest stops within a given time interval, and selects appropriate variants according to the expected scenarios and parameters derived from local surveys. For the city of Ostrava, Czechia, two commuting models were compared based on simulated movements to reach (a) randomly selected large employers and (b) proportionally selected employers using an appropriate distance-decay impedance function derived from various combinations of conditions. The validation of these models confirms the relevance of the proportional gravity-based model. Multidimensional evaluation of the potential accessibility of employers elucidates issues in several localities, including a high number of transfers, high total commuting time, low variety of accessible employers and high pedestrian mode usage. The transport accessibility evaluation based on synthetic trips offers an improved understanding of local situations and helps to assess the impact of planned changes.Web of Science1124art. no. 709

An Analysis of Storage Virtualization

Investigating technologies and writing expansive documentation on their capabilities is like hitting a moving target. Technology is evolving, growing, and expanding what it can do each and every day. This makes it very difficult when trying to snap a line and investigate competing technologies. Storage virtualization is one of those moving targets. Large corporations develop software and hardware solutions that try to one up the competition by releasing firmware and patch updates to include their latest developments. Some of their latest innovations include differing RAID levels, virtualized storage, data compression, data deduplication, file deduplication, thin provisioning, new file system types, tiered storage, solid state disk, and software updates to coincide these technologies with their applicable hardware. Even data center environmental considerations like reusable energies, data center environmental characteristics, and geographic locations are being used by companies both small and large to reduce operating costs and limit environmental impacts. Companies are even moving to an entire cloud based setup to limit their environmental impact as it could be cost prohibited to maintain your own corporate infrastructure. The trifecta of integrating smart storage architectures to include storage virtualization technologies, reducing footprint to promote energy savings, and migrating to cloud based services will ensure a long-term sustainable storage subsystem

Video-on-Demand over Internet: a survey of existing systems and solutions

Video-on-Demand is a service where movies are delivered to distributed users with low delay and free interactivity. The traditional client/server architecture experiences scalability issues to provide video streaming services, so there have been many proposals of systems, mostly based on a peer-to-peer or on a hybrid server/peer-to-peer solution, to solve this issue. This work presents a survey of the currently existing or proposed systems and solutions, based upon a subset of representative systems, and defines selection criteria allowing to classify these systems. These criteria are based on common questions such as, for example, is it video-on-demand or live streaming, is the architecture based on content delivery network, peer-to-peer or both, is the delivery overlay tree-based or mesh-based, is the system push-based or pull-based, single-stream or multi-streams, does it use data coding, and how do the clients choose their peers. Representative systems are briefly described to give a summarized overview of the proposed solutions, and four ones are analyzed in details. Finally, it is attempted to evaluate the most promising solutions for future experiments. Résumé La vidéo à la demande est un service où des films sont fournis à distance aux utilisateurs avec u

Development and testing of a portable GNSS network solution using the magellan propark3

With increasing development and expansion of Continuously Operating Reference Station (CORS)networks, globally and at home such as Sydnet, Global Navigation Satellite System users have greater options of utilizing reference station networks to receive correction data and undertake Real Time surveys without the need of supplying their own base station. A large majority of GNSS built today are equipped with built in mobile technology which utilize bidirectional communication including Internet based cellular connections. With increasing coverage of wireless internet, users will be able to utilize this technology in more places than they could ever before. The ProMark3 RTK GNSS receiver transmits correction data via a conventional 0.5 watt UHF radio. This allows a working range of up to 1.5km in open areas and 0.3 – 0.7km in urban built up areas. Unidirectional communication such as UHF also has its limitations including line of sight requirements, transmitter power, broadcasting antenna height limitations, reliability of the link and governmental restrictions such as licensing and operational limitations. Alternative options for receiving correction data are made available within the ProMark3’s onboard software, which include Networked Transmit of RTCM via Internet Protocol (NTRIP) and Direct Internet Protocol (DIP). These methods can extend that working range to 10km which is the recommended limit for RTK surveying. Built in wireless technology is not present in the ProMark3 however the user can still connect using a separate web enabled phone with Bluetooth technology. The advantage with this option is that the phone can be still used whilst you work, giving you even greater flexibility. This research project will explore the performance of the ProMark3 using Direct IP. Two different portable base reference stations to broadcast corrections will be designed. They include an office based and field based system. A rigorous testing regime will be conducted to explore the achievable range using Direct IP, the repeatability of position on an established baseline and the time taken to achieve a fixed solution at certain distances. The final part of this project will discuss the application of the technology to the surveying industry, particularly issues of reliability, cost and quality control. The use of CORS as an alternative to receiving correction data is improving work turn around time and field efficiencies, improving security as only one GPS is being utilized and offering survey firms the chance to experiment with this technology without a large expense upfront. The concept of a portable Direct IP station will allow users to operate privately run reference station networks from the office or the field. The benefit of a portable base station is that you can disassemble the base quickly and take it anywhere you decide to work. This will allow the operator and other users the chance to access data in areas not serviced by CORS and create opportunities for surveyors wanting to experiment with this alternate technology. The future may see an increasing amount of private CORS setup operating within existing government run networks, offering users even greater choice to access spatial data

Deep Space Network information system architecture study

The purpose of this article is to describe an architecture for the Deep Space Network (DSN) information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990s. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies, such as the following: computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control

AN INTERNET OF THINGS–BASED APPROACH TO INNOVATE CANTEEN STORES DEPARTMENT’S RETAIL OPERATIONS

In a competitive business environment, retail organizations in the Western world are capitalizing on technological tools and solutions to enhance customer experience and boost sales. Specifically, retailers that adopt Internet of Things (IoT) technologies improve customer experience and achieve cost savings. Yet such innovation is rare outside the Western world. Hence, early adopters of IoT technologies in retail operations in Pakistan could gain a competitive advantage. This study aims to create a deeper understanding of how Pakistan-based Canteen Stores Department (CSD), a retail chain mainly serving service members and their families, can use IoT technologies to significantly modernize and improve its operations and distinguish itself from competitors. To do so, this study conducts a qualitative analysis of scholarly articles on the relevant technologies and on IoT-based products offered by commercial companies. The authors also include findings from discussions with CSD customers and management. The results of the study indicate CSD can use IoT technologies to optimize store layout, offer interactive in-store mapping, automate checkout systems, implement smart shelving and digital price tagging, improve in-store promotions, enhance customer relationship management, and modernize distribution, transportation, and warehousing. The study also offers CSD management guidance on how to implement IoT technologies into retail operations at one location as a pilot.Outstanding ThesisLieutenant Commander, Pakistan NavyWing Commander, Pakistan Air ForceLieutenant Colonel, Pakistan ArmyApproved for public release. Distribution is unlimited

Static Web content distribution and request routing in a P2P overlay

The significance of collaboration over the Internet has become a corner-stone of modern computing, as the essence of information processing and content management has shifted to networked and Webbased systems. As a result, the effective and reliable access to networked resources has become a critical commodity in any modern infrastructure. In order to cope with the limitations introduced by the traditional client-server networking model, most of the popular Web-based services have employed separate Content Delivery Networks (CDN) to distribute the server-side resource consumption. Since the Web applications are often latency-critical, the CDNs are additionally being adopted for optimizing the content delivery latencies perceived by the Web clients. Because of the prevalent connection model, the Web content delivery has grown to a notable industry. The rapid growth in the amount of mobile devices further contributes to the amount of resources required from the originating server, as the content is also accessible on the go. While the Web has become one of the most utilized sources of information and digital content, the openness of the Internet is simultaneously being reduced by organizations and governments preventing access to any undesired resources. The access to information may be regulated or altered to suit any political interests or organizational benefits, thus conflicting with the initial design principle of an unrestricted and independent information network. This thesis contributes to the development of more efficient and open Internet by combining a feasibility study and a preliminary design of a peer-to-peer based Web content distribution and request routing mechanism. The suggested design addresses both the challenges related to effectiveness of current client-server networking model and the openness of information distributed over the Internet. Based on the properties of existing peer-to-peer implementations, the suggested overlay design is intended to provide low-latency access to any Web content without sacrificing the end-user privacy. The overlay is additionally designed to increase the cost of censorship by forcing a successful blockade to isolate the censored network from the rest of the Internet

SEARCH, REPLICATION AND GROUPING FOR UNSTRUCTURED P2P NETWORKS

In my dissertation, I present a suite of protocols that assist in efficient content location and distribution in unstructured Peer-to-Peer overlays. The basis of these schemes is their ability to learn from past interactions, increasing their performance with time. Peer-to-Peer (P2P) networks are gaining increasing attention from both the scientific and the large Internet user community. Popular applications utilizing this new technology offer many attractive features to a growing number of users. P2P systems have two basic functions: Content search and dissemination. Search (or lookup) protocols define how participants locate remotely maintained resources. In data dissemination, users transmit or receive content from single or multiple sites in the network. P2P applications traditionally operate under purely decentralized and highly dynamic environments. Unstructured systems represent a particularly interesting class of P2P networks. Peers form an overlay in an ad-hoc manner, without any guarantees relative to lookup performance or content availability. Resources are locally maintained, while participants have limited knowledge, usually confined to their immediate neighborhood in the overlay. My work aims at providing effective and bandwidth-efficient searching and data sharing. A suite of algorithms which provide peers in unstructured P2P overlays with the state necessary in order to efficiently locate, disseminate and replicate objects is presented. The Adaptive Probabilistic Search (APS) scheme utilizes directed walkers to forward queries on a hop-by-hop basis. Peers store success probabilities for each of their neighbors in order to efficiently route towards object holders. AGNO performs implicit grouping of peers according to the demand incentive and utilizes state maintained by APS in order to route messages from content holders towards interested peers, without requiring any subscription process. Finally, the Adaptive Probabilistic REplication (APRE) scheme expands on the state that AGNO builds in order to replicate content inside query intensive areas according to demand