571 research outputs found

    What makes a city 'smart'?

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    Taking advantage of information and communications technology tools and techniques for city administration, whether it is for urban planning activities, for transport solutions or many other purposes, is not a new concept. However, in order for a city to be classified as ‘smart’, a synthesis of intelligence that transcends mere utilisation is essential. This article analyses the increasing use of information and communications technology and sensing technologies in cities by examining this new way of city governing from a critical perspective. Existing projects and initiatives were investigated to find out how, and to what extent, these tools are being employed by cities. The advantages and the current shortcomings of smart city are also discussed in order to understand the viability of using these tools

    Supporting Massive Mobility with stream processing software

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    The goal of this project is to design a solution for massive mobility using LISP protocol and scalable database systems like Apache Kafka. The project consists of three steps: rst, understanding the requirements of the massive mobility scenario; second, designing a solution based on a stream processing software that integrates with OOR (open-source LISP implementation). Third, building a prototype with OOR and a stream processing software (or a similar technology) and evaluating its performance. Our objectives are: Understand the requirements in an environment for massive mo- bility;Learn and evaluate the architecture of Apache Kafka and similar broker messages to see if these tools could satisfy the requirements; Propose an architecture for massive mobility using protocol LISP and Kafka as mapping system, and nally; Evaluate the performance of Apache Kafka using such architecture. In chapters 3 and 4 we will provide a summary of LISP protocol, Apache Kafka and other message brokers. On these chapters we describe the components of these tools and how we can use such components to achieve our objective. We will be evaluating the di erent mechanisms to 1) authenticate users, 2) access control list, 3) protocols to assure the delivery of the message, 4)integrity and 5)communication patterns. Because we are interested only in the last message of the queue, it is very important that the broker message provides a capability to obtain this message. Regarding the proposed architecture, we will see how we adapted Kafka to store the information managed by the mapping system in LISP. The EID in LISP will be repre- sented by topics in Apache Kafka., It will use the pattern publish-subscribe to spread the noti cation between all the subscribers. xTRs or Mobile devices will be able to play the role of Consumers and Publisher of the message brokers. Every topic will use only one partition and every subscriber will have its own consumer group to avoid competition to consume the messages. Finally we evaluate the performance of Apache Kafka. As we will see, Kafka escalates in a Linear way in the following cases: number of packets in the network in relation with the number of topics, number of packets in the network in relation with the number of subscribers, number of opened les by the server in relation with the number of topics time elapsed between the moment when publisher sends a message and subscriber receives it, regarding to the number of topics. In the conclusion we explain which objectives were achieved and why there are some challenges to be faced by kafka especially in two points: 1) we need only the last location (message) stored in the broker since Kafka does not provide an out of the box mechanism to obtain such messages, and 2) the amount of opened les that have to be managed simultaneously by the server. More study is required to compare the performance of Kafka against other tools

    A generic framework for process execution and secure multi-party transaction authorization

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    Process execution engines are not only an integral part of workflow and business process management systems but are increasingly used to build process-driven applications. In other words, they are potentially used in all kinds of software across all application domains. However, contemporary process engines and workflow systems are unsuitable for use in such diverse application scenarios for several reasons. The main shortcomings can be observed in the areas of interoperability, versatility, and programmability. Therefore, this thesis makes a step away from domain specific, monolithic workflow engines towards generic and versatile process runtime frameworks, which enable integration of process technology into all kinds of software. To achieve this, the idea and corresponding architecture of a generic and embeddable process virtual machine (ePVM), which supports defining process flows along the theoretical foundation of communicating extended finite state machines, are presented. The architecture focuses on the core process functionality such as control flow and state management, monitoring, persistence, and communication, while using JavaScript as a process definition language. This approach leads to a very generic yet easily programmable process framework. A fully functional prototype implementation of the proposed framework is provided along with multiple example applications. Despite the fact that business processes are increasingly automated and controlled by information systems, humans are still involved, directly or indirectly, in many of them. Thus, for process flows involving sensitive transactions, a highly secure authorization scheme supporting asynchronous multi-party transaction authorization must be available within process management systems. Therefore, along with the ePVM framework, this thesis presents a novel approach for secure remote multi-party transaction authentication - the zone trusted information channel (ZTIC). The ZTIC approach uniquely combines multiple desirable properties such as the highest level of security, ease-of-use, mobility, remote administration, and smooth integration with existing infrastructures into one device and method. Extensively evaluating both, the ePVM framework and the ZTIC, this thesis shows that ePVM in combination with the ZTIC approach represents a unique and very powerful framework for building workflow systems and process-driven applications including support for secure multi-party transaction authorization

    Information-Centric Design and Implementation for Underwater Acoustic Networks

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    Over the past decade, Underwater Acoustic Networks (UANs) have received extensive attention due to their vast benefits in academia and industry alike. However, due to the overall magnitude and harsh characteristics of underwater environments, standard wireless network techniques will fail because current technology and energy restrictions limit underwater devices due to delayed acoustic communications. To help manage these limitations we utilize Information-Centric Networking (ICN). More importantly, we look at ICN\u27s paradigm shift from traditional TCP/IP architecture to improve data handling and enhance network efficiency. By utilizing some of ICN\u27s techniques, such as data naming hierarchy, we can reevaluate each component of the network\u27s protocol stack given current underwater limitations to study the vast solutions and perspectives Information-Centric architectures can provide to UANs. First, we propose a routing strategy used to manage and route large data files in a network prone to high mobility. Therefore, due to UANs limited transmitting capability, we passively store sensed data and adaptively find the best path. Furthermore, we introduce adapted Named Data Networking (NDN) components to improve upon routing robustness and adaptiveness. Beyond naming data, we use tracers to assist in tracking stored data locations without using other excess means such as flooding. By collaborating tracer consistency with routing path awareness our protocol can adaptively manage faulty or high mobility nodes. Through this incorporation of varied NDN techniques, we are able to see notable improvements in routing efficiency. Second, we analyze the effects of Denial of Service (DoS) attacks on upper layer protocols. Since UANs are typically resource restrained, malicious users can advantageously create fake traffic to burden the already constrained network. While ICN techniques only provide basic DoS restriction we must expand our detection and restriction technique to meet the unique demands of UANs. To provide enhanced security against DoS we construct an algorithm to detect and restrict against these types of attacks while adapting to meet acoustic characteristics. To better extend this work we incorporate three node behavior techniques using probabilistic, adaptive, and predictive approaches for detecting malicious traits. Thirdly, to depict and test protocols in UANs, simulators are commonly used due to their accessibility and controlled testing aspects. For this section, we review Aqua-Sim, a discrete event-driven open-source underwater simulator. To enhance the core aspect of this simulator we first rewrite the current architecture and transition Aqua-Sim to the newest core simulator, NS-3. Following this, we clean up redundant features spread out between the various underwater layers. Additionally, we fully integrate the diverse NS-3 API within our simulator. By revamping previous code layout we are able to improve architecture modularity and child class expandability. New features are also introduced including localization and synchronization support, busy terminal problem support, multi-channel support, transmission range uncertainty modules, external noise generators, channel trace-driven support, security module, and an adapted NDN module. Additionally, we provide extended documentation to assist in user development. Simulation testing shows improved memory management and continuous validity in comparison to other underwater simulators and past iterations of Aqua-Sim

    Nimbus 6 Random Access Measurement System applications experiments

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    The advantages of a technique in which data collection platforms randomly transmit signal to a polar orbiting satellite, thus eliminating satellite interrogation are demonstrated in investigations of the atmosphere; oceanographic parameters; Arctic regions and ice conditions; navigation and position location; and data buoy development

    8th SC@RUG 2011 proceedings:Student Colloquium 2010-2011

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    8th SC@RUG 2011 proceedings:Student Colloquium 2010-2011

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    8th SC@RUG 2011 proceedings:Student Colloquium 2010-2011

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