84 research outputs found

    Ohio River Denial as a Transportation Corridor and Its Economic Impacts on the Energy Industry

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    What if the Ohio River is disrupted or denied partially or completely as a transportation corridor? A disruption may be either a natural or man-made disaster or a planned outage on the river’s lock and dam structures. Recent history is full of water transport disruption events having significant economic effects on the waterside industries. To assess coal-based economic impacts, we developed a network flow model to represent waterside coal-fired power plants situated along the Ohio River, their respective coal supplying mines, and the various transportation modes that connect them. We show that significant transportation-centric insights can be derived by using only commonly available spreadsheet-based analysis tools, open-source information systems, and web-based geographic tools

    Power control for WCDMA

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    This project tries to introduce itself in the physical implementations that make possible the denominated third generation mobile technology. As well as to know the technology kind that makes possible, for example, a video-call in real time. During this project, the different phases passed from the election of WCDMA like the access method for UMTS will appear. Its coexistence with previous network GSM will be analyzed, where the compatibility between systems has been one of the most important aspects in the development of WCDMA, the involved standardization organisms in the process, as well as the different protocols that make the mobile communications within a network UTRAN possible. Special emphasis during the study of the great contribution that has offered WCDMA with respect to the control of power of the existing signals will be made. The future lines that are considered in the present, and other comment that already are in their last phase of development in the field of the mobile technology. UMTS through WCDMA can be summarized like a revolution of the air interface accompanied by a revolution in the network of their architecture

    스마트폰에서의 다속성 기반 다중 네트워크 운용 최적화 기법 연구

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    학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2015. 2. 최성현.Todays smartphones integrate multiple radio access technologies (multi-RAT), e.g., 3G, 4G, WiFi, and Bluetooth, etc. Moreover, state-of-the-art smartphones can activate multiple RAT interfaces simultaneously for the parallel transmission. Therefore, it is becoming more important to select the best RAT set among the available RATs, and determine how much data to transfer via each selected RAT network. We propose Energy, Service charge, and Performance Aware (ESPA), an adaptive multi-RAT operation policies for smartphone with supporting system design and multi-attribute cost function for smartphones Internet services including multimedia file transfer and video streaming services. ESPAs cost function incorporates battery energy, data usage quota, and service specific performance, simultaneously. These attributes are motivated by the growing sensitivity of todays smartphone users to these attributes. Each time the individual attributes are calculated and updated, ESPA selects the optimal RAT set that minimizes the overall cost. It can activate only the best one RAT interface or exploit multiple RATs simultaneously. The primary benefit of the ESPA is that it enables the smartphone to always operate in the best mode without the need for users manual controlthe energy saving mode if the remaining battery energy is becoming nearly depletedthe cost-saving mode if the remaining data quota is almost running outor, the performance-oriented mode if remaining data quota and battery energy are both sufficient. From Chapter 2 to Chapter 4, we cope with file transfer, video streaming, and standby mode for our proposed algorithms. The proposed algorithms are based on the service specific cost or utility models, which also take into account practical issues related to user satisfaction metrics. First, for file transfer mode, we apply the transfer completion time as the performance metric, and the energy consumption and service charge for downloading a specific size of file are simultaneously considered. Furthermore, we especially take into account a problem that the computational complexity exponentially increases as the number of available RATs increases. We propose a heuristic linear search algorithm to find the optimal RAT set without significant performance degradation. Secondly, for video streaming mode, we consider the HTTP-based video streaming model exploiting multipath with LTE and WiFi networks. Based on analysis of the energy consumption and data usage for the video streaming services, we propose a multi-RAT based video streaming algorithm that balances between the video quality, i.e., the performance metric, and the total playback time with currently given battery energy and data quota. Finally, we cope with the battery energy leakage issue of the smartphone in the standby mode due to intermittent traffic generated by some applications running on background. We analyze the energy-consuming factors in the standby mode and smartphone usage patterns of multiple users, and then, propose a usage pattern-aware deep sleep operation algorithm to save the battery energy in the standby mode. Simulation results based on real measurement data of the smartphone show that the ESPA algorithms indeed choose the best operational mode by maintaining dynamic balance among the performance, energy consumption, and service charge considering the currently provided services and the remaining resources.Abstract i Contents iv List of Tables vii List of Figures viii 1 Introduction 1 1.1 Energy, Service Charge, and Performance aware Multi-RAT Operation Policies for Smartphone 1.2 Overview of Existing Approaches 1.2.1 Multi-attribute based network selection 1.2.2 Energy and quota-aware video streaming services 1.2.3 Multi-path based approaches 1.3 Main Contributions 1.3.1 File transfer mode 1.3.2 Video streaming mode 1.3.3 Standby mode 1.4 Organization of the Dissertation 2 File Transfer Mode 2.1 Introduction 2.2 System Model 2.3 Problem Formulation 2.3.1 T-E-Q cost modeling 2.3.2 Optimization problem 2.4 Numerical Analysis 2.5 Proposed Algorithm 2.5.1 Bi-directional linear search algorithm 2.5.2 Dynamic update algorithm 2.6 Performance Evaluation 2.7 Summary 3 Video Streaming Mode 3.1 Introduction 3.2 System Model 3.2.1 HTTP-based playback model 3.2.2 LTE/WiFi-based multipath video streaming model 3.3 Chunk Download Cycle based Analysis 3.3.1 Data and energy consumption rate 3.3.2 Expected waste of data and energy 3.4 Proposed Scheme 3.4.1 Problem formulation 3.4.2 Subproblem I: Playback time maximization 3.4.3 Subproblem II: Balancing between encoding rate and total playback time 3.5 Performance Evaluation 3.5.1 Maximization of playback time with a single path 3.5.2 Balancing between video quality and playback time with LTE/WiFi multiple networks 3.6 Summary 4 Standby Mode 4.1 Introduction 4.2 Standby Mode Power Anatomy of Smartphones 4.2.1 Low power mode operation 4.2.2 Power consumption for background traffic 4.2.3 WiFi MAC overhead issue 4.3 Usage Log-based Idle Duration Analysis 4.3.1 User-specific daily distribution of idle duration 4.3.2 All-day distribution 4.3.3 Activity/inactivity time separation 4.4 Proposed Algorithm 4.4.1 Learning phase 4.4.2 Deep Sleep Mode (DSM) operation 4.5 Performance Evaluation 4.5.1 Performance comparison 4.5.2 Effect of Tonoff 4.6 Summary 5 Conclusion 5.1 Concluding Remarks Abstract (In Korean)Docto

    Exploiting user contention to optimize proactive resource allocation in future networks

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    In order to provide ubiquitous communication, seamless connectivity is now required in all environments including highly mobile networks. By using vertical handover techniques it is possible to provide uninterrupted communication as connections are dynamically switched between wireless networks as users move around. However, in a highly mobile environment, traditional reactive approaches to handover are inadequate. Therefore, proactive handover techniques, in which mobile nodes attempt to determine the best time and place to handover to local networks, are actively being investigated in the context of next generation mobile networks. The Y-Comm Framework which looks at proactive handover techniques has de�fined two key parameters: Time Before Handover and the Network Dwell Time, for any given network topology. Using this approach, it is possible to enhance resource management in common networks using probabilistic mechanisms because it is now possible to express contention for resources in terms of: No Contention, Partial Contention and Full Contention. As network resources are shared between many users, resource management must be a key part of any communication system as it is needed to provide seamless communication and to ensure that applications and servers receive their required Quality-of-Service. In this thesis, the contention for channel resources being allocated to mobile nodes is analysed. The work presents a new methodology to support proactive resource allocation for emerging future networks such as Vehicular Ad-Hoc Networks (VANETs) by allowing us to calculate the probability of contention based on user demand of network resources. These results are veri�ed using simulation. In addition, this proactive approach is further enhanced by the use of a contention queue to detect contention between incoming requests and those waiting for service. This thesis also presents a new methodology to support proactive resource allocation for future networks such as Vehicular Ad-Hoc Networks. The proposed approach has been applied to a vehicular testbed and results are presented that show that this approach can improve overall network performance in mobile heterogeneous environments. The results show that the analysis of user contention does provide a proactive mechanism to improve the performance of resource allocation in mobile networks

    Power control for WCDMA

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    This project tries to introduce itself in the physical implementations that make possible the denominated third generation mobile technology. As well as to know the technology kind that makes possible, for example, a video-call in real time. During this project, the different phases passed from the election of WCDMA like the access method for UMTS will appear. Its coexistence with previous network GSM will be analyzed, where the compatibility between systems has been one of the most important aspects in the development of WCDMA, the involved standardization organisms in the process, as well as the different protocols that make the mobile communications within a network UTRAN possible. Special emphasis during the study of the great contribution that has offered WCDMA with respect to the control of power of the existing signals will be made. The future lines that are considered in the present, and other comment that already are in their last phase of development in the field of the mobile technology. UMTS through WCDMA can be summarized like a revolution of the air interface accompanied by a revolution in the network of their architecture

    A container-based architecture to provide services from SDR devices

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    Rádio Definido por Software (SDR) é um dispositivo de rádio programável que, conectado a um computador ou como uma solução embarcada, pode transmitir e receber informações usando ondas de rádio. A característica de programabilidade do SDR e sua largura de banda de rádio frequência (RF) estendem sua aplicação a diversas áreas que incluem aviação, satélite, radar e dispositivos móveis. O emprego do SDR tem despertado grande interesse na provisão de serviços de rede. Atuando como uma interface sem-fio multiprogramável na borda de redes cabeadas, o SDR é capaz de transmitir, receber e decodificar informações de rádio. Estas informações são usadas para fornecer serviços, como por exemplo uma página de internet contendo um mapa de rastreamento de aeronaves em tempo real, e gráficos de monitoramento de sensores. No entanto, para ser usado para esta finalidade, o SDR deve integrar-se às correntes tecnologias dos ambientes de rede, como NFV, SDN, containerização, e a computação em nuvem. Esta dissertação está focada na integração do SDR com a technologia de containerização. É proposta uma arquitetura para geração de serviços usando contâineres e o SDR como dispositivo de borda. Usando diferentes modelos de SDRs (USRP, LimeSDR e RTL-SDR), a plataforma GNURadio e Docker containers, dois cenários de aplicação da arquitetura são apresentados, nos quais a comunicação ADS-B e LoRa são implementadas. A avaliação da solução proposta é realizada comparando-se a geração de serviço com a arquitetura, (com dois níveis de isolação de rede), e sem a arquitetura. O tempo de lançamento e de resposta dos serviços, e a utilização dos recursos computacionais são comparados, mostrando que a arquitetura tem impacto nesses fatores. Este impacto aumenta conforme o nível de isolação de rede utilizado. Por outro lado a arquitetura aplica uma topologia que converte os componentes funcionais do serviço em blocos modulares, tornando possível sua aplicação em diferentes projetos de RF, e oferece benefícios não funcionais, como a capacidade de prover serviços em tempo real, emprego com diferentes modelos de SDR, e isolação de rede. Além disso, a arquitetura adiciona uma série de características de controle herdadas da tecnologia de virtualização.Software Defined Radio is a programmable radio device that, when connected to a computer or as an embedded solution, can transmit and receive data information using radio waves. The programming features of the SDR and its RF bandwidth range extends the application possibility to several areas, including aviation, satellite, radar, and mobile communication. SDR has drawn great attention to network service provision. Acting as a multi-programmable air interface at the edge of wired network environments, SDR can receive, decode and forward radio information, which is used to generate the services. Examples of services including real-time flight tracker web pages, and sensor monitoring data charts. However, to provide network services, SDR must integrate into complex network environments where recent technologies, such as NFV, SDN, containerization and cloud computing, are applied. This thesis addresses the integration of SDRs with containerization. It proposes an easy-to-deploy container-based architecture to provide network services from SDR devices. Using different types of SDR devices (USRP, LimeSDR and RTL-SDR), GNURadio platform and Docker Container, two use cases of the proposed architecture are presented, demonstrating scenarios where ADSB and LoRa communication are implemented in order to provide services to end-users. Evaluation of the proposed solution is performed comparing two models of service provision: with the proposed architecture (two levels of network isolation), and without the architecture. The overhead time added to launch the services, the time response and computational resource utilization are compared, showing that there is an overhead added by the architecture which impacts on the system performance. The overhead increases with the applied network isolation level. Conversely, the architecture converts the service functional components into modular components, its application can be extended to different RF projects and SDR types, and offers non-functional benefits such as, real-time capability, network isolation, fine setting of communication parameters, and a set of control and configuration features inherited from container virtualization platform

    Cargo Logistics Airlift Systems Study (CLASS). Volume 3: Cross impact between the 1990 market and the air physical distribution systems, book 1

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    The interrelations between the infrastructure and the forecast future market are discussed. Also, using forecasts of market growth for a base, future aircraft and air service concepts were evaluated

    Aeronautical engineering, a continuing bibliography with indexes

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    This bibliography lists 419 reports, articles and other documents introduced into the NASA scientific and technical information system in March 1985

    Contribution to the Design of Digital Supply Chain Governance Concepts for Sustainable Development of Biodiesel

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    Biodiesel sowie Biokraftstoffe wurden in der letzten Zeit zunehmend in mehreren Vorträgen und Konferenzen diskutiert. Während viele der wissenschaftlichen Untersuchungen die Produktionsprobleme, wie Effizienz, Diversifizierung und Prozesstechnologie (1, 2, 3 generation) behandelten, wurde jedoch nur in einigen davon Biodiesel aus der logistischen Perspektive betrachtet. Trotzdem stellt Biodiesel ein Problem für die logistischen Prozesse dar, so wie Anlagenplanung, Transport und Tourenplanung verbunden mit der Qualitätskontrolle entlang der Kontinuität der Rohmaterialversorgung. In einigen Entwicklungsländern ist das Management der Biodiesel-Industrie in eine Zwangslage geraten. Obwohl Entwicklungsländer gemeinsam eine nationale Behörde für das Biodiesel-Geschäft eingeführt haben, ist die Institution nach wie vor in den frühen Stadien der Standardisierung sowie Qualitätskontrolle. Derzeit gibt es keine Agentur für die Supply Chain Führung, die für die Integration des Biodiesel-Geschäftes zwischen vorgelagerten und nachgelagerten Bereiche fähig ist. In dieser Arbeit stellt der Autor eine Prozesstechnik vor, um die die Biodiesel-Industrie zu bewerten. Diese Prozedur kombiniert Geschäftsmodell/-analyse (unter Nutzung der General Electric/Mc. Kinsey Matrix), Simulation, Konzeptentwurf und ein Prototyping-System. Die Studie leistet einen wissenschaftlichen Beitrag für die Planung einer digitalen Biodiesel Supply Chain und bildet einen Rahmen für die Führung eines solchen Systems vom vorgelagertem zum nachgelagerten Bereich. Der Forscher verwendet eine ganzheitliche Betrachtung, wo Biodiesel nicht als eine gesonderte Einheit gesehen wird, aufgrund der Tatsache, dass es den Konsumenten, abhängig von unterschiedlichen Aspekten, von einer langen Kette ankommt. Um ihre Geschäfte zu managen, haben viele Unternehmen Enterprise-Resource-Planning eingeführt, aber leider waren sie nicht in der Lage die gesamte Wertschöpfungskette damit zu erreichen. Digitalisierung ist bei der Integration des Informationssystems von allen Supply Chain Mitgliedern wünschenswert. Um solch eine Idee anzupassen sowie den gesamten Prozess zu überwachen, muss ein Kontrollturm gebaut werden. In Folge dessen könnte die beste standardisierte Qualität und Nachhaltigkeit erreicht werden. Der Autor schlägt ebenso ein Übergangskonzept in der Implementierungsebene vor, aufgrund der Tatsache, dass die Supply Chain Mitglieder in der Realität keine ähnlichen Informationssystem-Standards zur Verfügung haben. Das Ergebnis der Literatur-Studien, Simulationen, Prototypenentwicklungen, theoretischen Argumente und Konzeptentwürfen präsentiert eine Digitalisierungsmuster in der Supply Chain von Biodiesel für die nachhaltige Entwicklung.Recently, biodiesel and biofuel have increasingly been discussed in several papers and conferences. However, only a few have examined biodiesel from the logistics perspective, while most of the scientific investigations have addressed the production issues, e.g. efficiency, diversification and processing technology (1st, 2nd or 3rd generation). In spite of this, biodiesel poses a problem for logistic processes, such as facility planning, transport, and routing-scheduling associated with quality control along with continuity of feedstock supply. In some developing countries, the management of the biodiesel industry has also become a predicament. Even though developed countries have commonly established a national agency in charge of the biodiesel business, the institution is still in the early stages of standardisation and quality control. Currently, there is no agency concerned with supply chain governance that is capable of integrating the biodiesel business from upstream to downstream. In this thesis, the author presents a procedural technique to assess the biodiesel industry. This procedure combines business modelling/analysis (using General Electric/Mc. Kinsey Matrix), simulation, conceptual design and a prototyping system. The study provides scientific insight for planning a digital biodiesel supply chain and proposes a framework for governing such a system from upstream to downstream. The researcher employs a holistic approach, where biodiesel is not seen as a separate entity because it comes to the consumers through a long chain dependent on various aspects. Currently, a number of companies have implemented Enterprise-Resource-Planning to manage their businesses, but unfortunately, they have not been able to reach the entire value chain. Digitalisation is desirable when integrating the Information Systems of all supply chain members. A control tower must be built to accommodate such an idea and monitor the entire process. Then, the best standardised quality and sustainability can be achieved. The author also offers a transition concept in the implementation level, because, in reality, the members in the supply chain have no similar Informastion-System standard. The results from literature studies, simulations, prototyping, theoretical arguments, and conceptual design present a digitalisation pattern in the biodiesel supply chain for sustainable development
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