The calling of users is very uneven and the channel collision detection ability is quite weak in communication system in near space (CSNS). To ensure quality of service (QoS), a novel load measurement access control (...
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ISBN:
(纸本)9781424413119
The calling of users is very uneven and the channel collision detection ability is quite weak in communication system in near space (CSNS). To ensure quality of service (QoS), a novel load measurement access control (LMAC) protocol is proposed. Combined with Markov M/M/n queue model, integrated theoretical analytical model is established for CSNS. The effect which the waiting probability of calling service, calling number and measure parameter have on the performance of the networks are analyzed. Besides, the LMAC scheme Is introduced to greatly increase the maximum throughput to 0.33 and improves the maximum throughput nearly one time compared to the maximum throughput 0.18 of the simple ALOHA protocol and closed to the theoretical bound.
In the late 1960s the US Air Force Logistics Command (AFLC) engaged in an unparalleled, real-time computer networking project to manage all its logistics (location, inventory, maintenance, and transportation of person...
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ISBN:
(数字)9783642151996
ISBN:
(纸本)9783642151989
In the late 1960s the US Air Force Logistics Command (AFLC) engaged in an unparalleled, real-time computer networking project to manage all its logistics (location, inventory, maintenance, and transportation of personnel, aircraft, weapons, components, spare parts, etc.), the Advanced Logistics System (ALS). The $250 million ALS project was substantially larger in size and cost than earlier real-time computer networking projects (including SAGE programming and SABRE), but it has received virtually no attention from historians of computing. Ultimately, the ALS project failed. Drawing from an oral history with lead contractor control Data's (CDC) longtime ALS project manager, previously unavailable CDC documents, and documentation and an oral history from a leading external Air Force advisor on ALS, it shows how the AFLC pushed too far too fast in seeking to be a first-mover in creating a massive unified database and real-time computer network for highly complex logistics.
Recent advances in cooperative driving hold the potential to significantly improve safety, comfort and efficiency on our roads. An application of particular interest is platooning of trucks, where it has been shown th...
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ISBN:
(纸本)9781457720147
Recent advances in cooperative driving hold the potential to significantly improve safety, comfort and efficiency on our roads. An application of particular interest is platooning of trucks, where it has been shown that keeping a minimum inter-vehicle distance results in considerably reduced fuel consumption. This, however, puts high requirements on timeliness and reliability of the underlying exchange of control messages between platoon members. The European profile of IEEE 802.11p, recently adopted by ETSI, defines two message types to this end, periodic beacons for basic cooperative awareness (CAM) and event-triggered decentralized environmental notification messages (DENM), both of which will use one common control channel. IEEE 802.11p employs a random medium access protocol, which may experience excessive delays during high network loads. To mitigate these effects, ETSI standardizes a decentralized congestion control algorithm to, e. g., lower the CAM update frequency during high loads. However, this may prevent proper functionality of a platooning application. In this paper we propose a solution that instead uses a dedicated service channel for platooning applications and compare its performance to standard-compliant IEEE 802.11p inter-platoon communication on the control channel. Service channels typically have less strict requirements on send rates, data traffic types and medium access methods. Our service channel solution combines a random access phase for DENM with a centralized, scheduled access phase for CAM. Using a service channel enables us to guarantee timely channel access for all CAM packets before a specified deadline while still being able to provide a reasonable DENM dissemination delay.
This work aims to present a control scheme for an experimental, highly nonlinear Multi-Input Multi-Output (MIMO) Quadruple Tank System (QTS) using Decentralized Proportional Integral (DPI) control. controllers are des...
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ISBN:
(纸本)9781538641460
This work aims to present a control scheme for an experimental, highly nonlinear Multi-Input Multi-Output (MIMO) Quadruple Tank System (QTS) using Decentralized Proportional Integral (DPI) control. controllers are designed for minimum and non-minimum phases of the QTS system and the respective performance analyses of the designed controllers for both the phases are carried out through simulations in MATLAB/SIMULINK.
Named Data network consists of three data structures for forwarding the incoming Interest packets. Whenever the interest packet arrives, it has to search in the pending interest table and the content store. When a lar...
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An innovative and smart micro-grid model is an essentialfor the integration of distributed energy resources into the electrical power distribution network. There are various types of micro-grid architectures that have...
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The volume includes a set of selected papers extended and revised from the 2011 internationalconference on Computer, communication, control and Automation (3CA 2011). 2011 internationalconference on Computer, Commun...
ISBN:
(纸本)9783642255373
The volume includes a set of selected papers extended and revised from the 2011 internationalconference on Computer, communication, control and Automation (3CA 2011). 2011 internationalconference on Computer, communication, control and Automation (3CA 2011) has been held in Zhuhai, China, November 19-20, 2011. This volume topics covered include wireless communications, advances in wireless video, wireless sensors networking, security in wireless networks, network measurement and management, hybrid and discrete-event systems, internet analytics and automation, robotic system and applications, reconfigurable automation systems, machine vision in automation. We hope that researchers, graduate students and other interested readers benefit scientifically from the proceedings and also find it stimulating in the process.
Even if both traditional centralized and decentralized models can support small conferences, their deployment for large number of participants is less obvious. In fact, while server-based centralized conference facili...
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ISBN:
(纸本)9780769533933
Even if both traditional centralized and decentralized models can support small conferences, their deployment for large number of participants is less obvious. In fact, while server-based centralized conference facilitates control and administration operations, supporting centralized media processing in large scale conference causes system overhead on the mixer. On the other hand, decentralized solutions that use multi end-system media processors will introduce an overhead to controlconference floors and users membership. Our solution introduces a new model that enable multi-host media process support while the conferencecontrol and management is kept simplified and centralized around the administrator. To do that, we build two different meshed networks to enable both voice audio distribution between participants and general conferencecontrol. In this short paper we introduce our system topology and indentify components that enable conference creation/destruction, user addition/removal, media assignment and speech floor control.
This research aimed to study the usage of social networking sites (SNSs) for education in the higher education context. The survey research consisted of 412 university students who used social networking sites. The ma...
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ISBN:
(纸本)9783319420707;9783319420691
This research aimed to study the usage of social networking sites (SNSs) for education in the higher education context. The survey research consisted of 412 university students who used social networking sites. The main purposes of students for the usage of SNSs in education were to communicate with their classmates and lecturers rather than collaborate on their academic work or use them as a space for information resource sharing. The students revealed that the main advantages they received from using SNSs were easy and convenient ways to search for information, effective ways to contact or communicate with classmates and lecturers, and closer relationship among friends. Regarding the psychological factors that influenced the usage of SNSs in the educational context were subjective norms, compatibility between technology and users, and attitude toward technology. In addition, SNSs usage also correlated with its positive outcome in the context of education. The problems and obstacles the students faced from using SNSs in the educational context were management of time spending online and misinterpretation of non-face-to-face communication.
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