This thesis describes the application of a distributed system architecture framework and Architecture Flow Optimization (AFO) to naval ship Concept & Requirements Exploration (C&RE). It describes refinements to both C&RE and AFO, and naval surface combatant concept design case studies. The architectural framework decomposes naval ship distributed systems into the physical, logical, and operational architectures representing the spatial, functional, and temporal relationships of distributed systems respectively. This decomposition greatly simplifies the Mission, Power, and Energy System (MPES) design process for use in C&RE. AFO is a network-based linear programming optimization method used to design and analyze MPES at a sufficient level of detail to understand system energy flow, define MPES architecture and sizing, reduce system vulnerability and improve system reliability. AFO incorporates system topologies, energy coefficient component models, preliminary arrangements, and (nominal and damaged) steady state scenarios to minimize the energy flow cost required to satisfy all operational scenario demands and constraints. This thesis provides an overview of design tools developed to implement this process and methods, including objective attribute metrics for cost, effectiveness and risk, ship synthesis model, hullform exploration and MPES explorations using design of experiments (DOEs) and response surface models. / M.S. / The design of modern warships presents many unique challenges not faced in the design of most commercial ships or past generations of warships. The objectives of warship design (e.g. effectiveness, design risk, and total lifecycle cost) cannot be summarized in a single quantitative metric as commonly done in commercial ship design (e.g. required freight rate: the minimum market price of a commodity to make a commercial ship design with a certain cargo capacity profitable). Furthermore, misison, power, and energy systems (MPES) of modern warships have become increasingly interdependent and complex, especially those of naval surface combatants (non-submarine warships designed to engage in direct combat with other ships). Determining quantitative metrics for these objectives is a difficult task to begin with. Determining accurate values for these metrics in early stage design (when designs have little detailed specifications and some technologies may even be still be in development) is another challenge altogether. This thesis describes simple and robust methods and processes to evaluate a warship’s arrangement and operational characteristics. Survivability characteristics, characteristics related to a warship’s ability to complete missions despite battle damage, are of particular interest in these methods. These methods incorporate physics and energy-based means of assessment rather than using historical parametric models that are insufficient in assessing new and revolutionary warship designs.

ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / Spectrum allocation in wireless communication and telemetry systems of the future may be performed in a dynamic and distributed manner, as opposed to static centralized regulations currently in place. This paper surveys a new area of research in the communications field known as cognitive radio which will allow dynamic sharing of spectral bands. An introduction to cognitive radio, a review of existing research results, and discussion of open problems in the area is provided.

This work describes the design and implementation of the Disease Control System DiCon (pronounced [ˈdaɪkɒn]), providing a general framework for solving optimization problems on distributed computer systems. The central aspects of DiCon are discussed, as are decisions made while realizing the system. Several implementation-specific details are highlighted. Real-world applications show the system's flexibility and demonstrate the potential impact DiCon has on public-health decision making. / text

Internet of things (IoT) generates massive amount of heterogeneous data, which should be efficiently utilized to support services in different domains. Specifically, data need to be supplied to services by understanding the needs of services and by understanding the environment changes, so that necessary data can be provided efficiently but without overfeeding. However, it is still very difficult for IoT to fulfill such data supply with only the existing supports of communication, network, and infrastructure; while the most essential issues are still unaddressed, namely the heterogeneity issue, the recourse coordination issue, and the environments’ dynamicity issue. Thus, this necessitates to specifically study on those issues and to propose a method to utilize the massive amount of heterogeneous data to support services in different domains. This dissertation presents a novel method, called the data-centric network of things (DNT), which handles heterogeneity, coordinates resources, and understands the changing IoT entity relations in dynamic environments to supply data in support of services. As results, various services based on IoT (e.g., smart cities, smart transport, smart healthcare, smart homes, etc.) are supported by receiving enough necessary data without overfeeding. The contributions of the DNT to IoT and big data research are: firstly the DNT enables IoT to perceive data, resources, and the relations among IoT entities in dynamic environments. This perceptibility enhances IoT to handle the heterogeneity in different levels. Secondly, the DNT coordinates IoT edge resources to process and disseminate data based on the perceived results. This releases the big data pressure caused by centralized analytics to certain degrees. Thirdly, the DNT manages entity relations for data supply by handling the environment dynamicity. Finally, the DNT supply necessary data to satisfy different service needs, by avoiding either data-hungry or data-overfed status.

Title: Supporting multiplatform applications with YA-RPC Author: František Kovařík Department: Department of Software Engineering Supervisor: RNDr. Petr Hnětynka, Ph.D. Supervisor's e-mail address: hnetynka@d3s.mff.cuni.cz Abstract: Over the last three decades, Remote Procedure Call (RPC) has become a popular inter-computer and inter-process communication paradigm widely used by a variety of interconnected computer systems. Even though a number of RPC protocols and implementations evolved over those years, no single system offers a significant set of features, while providing an easy-to-use application programming interface. In this thesis, we present Yet Another Remote Procedure Call - YaRpc, a specification of a flexible and programmer friendly middleware that offers advanced features such as pluggable transports and protocols, callbacks, and configurable method dispatch. Additionally, we define YaRpc Native Protocol (YNP), a new light-weight high-performance RPC protocol with a rich set of features. We provide a native implementation of both YaRpc middleware and YNP protocol for Java and .NET Framework, and compare its usability with Java RMI, .NET Remoting and SOAP web services. Keywords: YaRpc, remote procedure call, distributed system

Title: Supporting multiplatform applications with YA-RPC Author: František Kovařík Department: Department of Software Engineering Supervisor: RNDr. Petr Hnětynka, Ph.D. Supervisor's e-mail address: hnetynka@d3s.mff.cuni.cz Abstract: Over the last three decades, Remote Procedure Call (RPC) has become a popular inter-computer and inter-process communication paradigm widely used by a variety of interconnected computer systems. Even though a number of RPC protocols and implementations evolved over those years, no single system offers a significant set of features, while providing an easy-to-use application programming interface. In this thesis, we present Yet Another Remote Procedure Call - YaRpc, a specification of a flexible and programmer friendly middleware that offers advanced features such as pluggable transports and protocols, callbacks, and configurable method dispatch. Additionally, we define YaRpc Native Protocol (YNP), a new light-weight high-performance RPC protocol with a rich set of features. We provide a native implementation of both YaRpc middleware and YNP protocol for Java and .NET Framework, and compare its usability with Java RMI, .NET Remoting and SOAP web services. Keywords: YaRpc, remote procedure call, distributed system

Building Automation System (BAS) is a complex distributed control system that is widely deployed in commercial, residential, industrial buildings for monitoring and controlling mechanical/electrical equipment. Through increasing industrial and technological advances, the control components of BAS are becoming increasingly interconnected. Along with potential benefits, integration also introduces new attack vectors, which tremendous increases safety and security risks in the control system. Historically, BAS lacks security design and relies on physical isolation and "security through obscurity". These methods are unacceptable with the "smart building" technologies. The industry needs to reevaluate the safety and security of the current building automation system, and design a comprehensive solution to provide integrity, reliability, and confidentiality on both system and network levels. This dissertation focuses on the system level in the effort to provide a reliable computing foundation for the devices and controllers. Leveraged on the preferred security features such as, robust modular design, small privilege code, and formal verifiability of microkernel architecture, this work describes a security enhanced operating system with built-in mandatory access control and a proxy-based communication framework for building automation controllers. This solution ensures policy-enforced communication and isolation between critical applications and non-critical applications in a potentially hostile cyber environment.

[pt] Arquiteturas P2P destacam-se pela descentralização e pelo incentivo a cooperação entre nós. Essas características permitem que sistemas baseados nesta arquitetura sejam tolerantes a falhas e que os recursos sejam distribu ídos entre os nós (via replicação). A utilização da técnica de DHT na criação de redes P2P permite que os sistemas sejam escaláveis. Ao contrário do uso mais comum em sistemas de distribuição de conteúdo, este trabalho investiga aplicacações da técnica de DHT em sistemas de computação distribu ída, onde o recurso compartilhado é a capacidade de processamento de cada nó. Quatro protocolos de roteamento de mensagens foram analisados para identificar os mais adequados aos sistemas de computação distribuída e aplicou-se o conceito de grupo de nós com o objetivo de aumentar a tolerância a falhas e distribuir tarefas entre os nós da rede. / [en] P2P architectures are recognized for decentralization and incentive for the cooperation among nodes. These characteristics allow for fault tolerance and resource distribution among the nodes (by replication) to systems based on the P2P architecture. Systems based in P2P networks built using the DHT technique are scalable. Since this architecture is commonly used in content distribution systems, in this work we investigate the utilization of the DHT technique in distributed computing systems, where the shared resources are the node’s computational power. Four routing protocols were analyzed to identify the most appropriated for use in distributed computing systems and applied the group concept to archive fault tolerance and resource distribution among nodes.

<p>Much functionality of today's vehicles runs as software on embedded computer systems. This includes, for example, automatic climate control and engine control.</p><p>As the processors necessarily are located in diffent physical locations inside the vehicle wires must be drawn between processors that need to communicate. Therefore, it is typical to have one or several buses connecting the processors in an embedded computer network, thus creating a distributed system. As some parts of the system in the car have real-time properties, it is necessary to validate that the real-time properties are upheld in the distributed system.</p><p>This thesis presents the design and implementation of an adaptive cruise controller (ACC), which is a cruise controller that also keeps a minimum distance to the closest vehicle in front. Further, the performance of the ACC has been evaluated using an existing system-level simulator for distributed real-time systems together with metrics for Quality-of-Control (QoC).</p><p>The ACC has then been simulated under different scenarios. The scenarios include outside conditions, for example the slope of the road, the behaviour of the vehicle in front, and the desired velocity, as well as internal conditions as adding different amounts of extra load on the processors and the bus.</p><p>The results show that the functionality of the ACC starts deteriorating when the extra load on the nodes reaches high levels. When the extra load reaches very high levels, the ACC stops functioning completely. The results also show that the extra load on the bus has very little effect on the performance of the ACC.</p>

Due to the limitation of single machine¡¦s computing power, and the aspect of cost, distributed design is getting more and more popular nowadays. The Distributed Shared Memory (DSM) system is one of the most hot topics in this area. Most people are dedicated on designing a library or even a new language, in order to gain higher performance on DSM systems. As a consequence, the programmers are required to learn a new library or language. Even more, they have to handle synchronizations for the distributed environment. In this paper, we propose a design that is compatible with POSIX-Thread Environment. The distributed nature of the system described herein is totally transparent to the programmers.