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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Revised AODV Routing Protocol with Energy Management for Real-Time/Non-Real-Time Services in Mobile Ad Hoc Network

Chung, Wen-Ju 13 August 2008 (has links)
As the growth of multimedia communications involving digital audio and video, it is increasingly important for the MANET (Mobile Ad Hoc Network) routing protocols to simultaneously support both real-time and non-real-time traffic. MANET energy management should offer this support because devices are equipped with limited battery power. To achieve this end, we revise the Ad hoc On-demand Distance Vector (AODV) routing protocol to provide an energy management mechanism such that both real-time and non-real-time packets can be effectively transmitted. In the proposed scheme, real-time traffic uses higher transmission power to reduce transmission delay time and selects a shortest route with the largest minimum residual energy to avoid route break. The non-real-time traffic uses normal transmission power to save energy and chooses a proper shortest route with highest average residual energy to balance node energy consumption. The simulation results show that the revised AODV obtains lower average end-to-end delay and fewer energy-exhausted nodes comparing to the conventional AODV.
2

A constrained computational model for flexible scheduling

McElhone, Charles Gerard January 1996 (has links)
No description available.
3

Computational architecture : a step towards predictable software design

Vickers, Andrew J. January 1994 (has links)
No description available.
4

Implementation of a Low Cost Commercial-Off-the-Shelf Commanding System

Grich, Richard J., Jr., Bourassa, Chris R. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Traditional satellite and launch control systems have consisted of custom solutions requiring significant development and maintenance costs. These systems have typically been designed to support specific program requirements and are expensive to modify and augment after delivery. Over the past five years, technical advances have resulted in Commercial-Off-The-Shelf (COTS) products which greatly reduce the complete life cycle costs associated with satellite and launch control system procurements. These advances, however, have been restricted to specific functional areas of the satellite and launch control system - most notably, telemetry processing and simulation. Until recently, technological advances in the development of COTS products which support functional areas like commanding and mission planning have lagged behind. This paper describes the development and application of a COTS product which provides a highly advanced commanding capability that is tightly integrated with the processing of telemetry data. This closed loop telemetry and commanding system forms the basis of a satellite or launch control system at a fraction of the cost normally associated with systems of this kind.
5

Modulation of cell yields and genetic responses of Salmonella fermentation and colonization in the gastrointestinal ecology of avian species

Dunkley, Kingsley Delroy 15 May 2009 (has links)
In these studies we evaluated specific environmental stimuli relevant to Salmonella virulence and physiology in the gastrointestinal tract of chickens. Results from Salmonella growth in steady state, glucose-limiting continuous culture (CC) indicated that the optimal growth condition was observed between 0.05 h-1 and 0.27 h-1 dilution rates (D). Cell protein concentrations increased proportionally with an increase in D at each steady state, but after D 0.27 h-1 there was a reduction in the cell protein concentrations as the D increased. Genetic responses generally indicated that the lowest D exhibited highest hilA relative expression. Relatively higher expression of hilA was largely observed at low D (low glucose) (0.0125 h-1, 0.025 h-1, 0.05 h-1). Salmonella incubated in CC at different pH shifts demonstrated that cell protein concentration, glucose utilization, Yield ATP and Acetate:Propionate ratios were influenced by an increase in pH (6.14 to 7.41). These parameters increased and decreased consistently with a corresponding increase and decrease in pH. Polymerase chain reaction-based denaturant gradient gel electrophoresis showed that the overall amplicon band patterns of microbial similarity have demonstrated that hens molted with Alfalfa (ALC+) diet were similar to the Full-Fed (FF+) treatment group. Additional, FF+ and ALC+ treatment groups exhibited a higher percentage similarity coefficient (>90%) than the feed deprived treatment group. Fermentation response from cecal inocula on feed substrates revealed that alfalfa based samples yielded consistently higher short chain fatty acid levels when compared to other feed substrates. Salmonella Enteritidis (SE) colonization in liver, spleen and ovaries was significantly (P < 0.05) higher in FW+ hens compared to ALC+ and FF+ treatments groups. A 4-fold (log10 1.29) reduction in SE colonization for ALC+ hens compared to feed withdrawal hens (FW+) (log10 5.12) SE colonization was observed. Relative expression of hilA in all treatment groups was significantly (P < 0.05) higher in FW+ compared to FF+ and ALC+ groups. hilA expression in FW+ hens was 3.2-, 4.2-, and 1.9-fold higher for Days 6, 11 and 12 respectively, when compared with to ALC+ hens. These results suggest that Salmonella virulence in the gastrointestinal ecology of chickens could be impacted by a combination of low nutrients availability and pH shifts.
6

Modulation of cell yields and genetic responses of Salmonella fermentation and colonization in the gastrointestinal ecology of avian species

Dunkley, Kingsley Delroy 15 May 2009 (has links)
In these studies we evaluated specific environmental stimuli relevant to Salmonella virulence and physiology in the gastrointestinal tract of chickens. Results from Salmonella growth in steady state, glucose-limiting continuous culture (CC) indicated that the optimal growth condition was observed between 0.05 h-1 and 0.27 h-1 dilution rates (D). Cell protein concentrations increased proportionally with an increase in D at each steady state, but after D 0.27 h-1 there was a reduction in the cell protein concentrations as the D increased. Genetic responses generally indicated that the lowest D exhibited highest hilA relative expression. Relatively higher expression of hilA was largely observed at low D (low glucose) (0.0125 h-1, 0.025 h-1, 0.05 h-1). Salmonella incubated in CC at different pH shifts demonstrated that cell protein concentration, glucose utilization, Yield ATP and Acetate:Propionate ratios were influenced by an increase in pH (6.14 to 7.41). These parameters increased and decreased consistently with a corresponding increase and decrease in pH. Polymerase chain reaction-based denaturant gradient gel electrophoresis showed that the overall amplicon band patterns of microbial similarity have demonstrated that hens molted with Alfalfa (ALC+) diet were similar to the Full-Fed (FF+) treatment group. Additional, FF+ and ALC+ treatment groups exhibited a higher percentage similarity coefficient (>90%) than the feed deprived treatment group. Fermentation response from cecal inocula on feed substrates revealed that alfalfa based samples yielded consistently higher short chain fatty acid levels when compared to other feed substrates. Salmonella Enteritidis (SE) colonization in liver, spleen and ovaries was significantly (P < 0.05) higher in FW+ hens compared to ALC+ and FF+ treatments groups. A 4-fold (log10 1.29) reduction in SE colonization for ALC+ hens compared to feed withdrawal hens (FW+) (log10 5.12) SE colonization was observed. Relative expression of hilA in all treatment groups was significantly (P < 0.05) higher in FW+ compared to FF+ and ALC+ groups. hilA expression in FW+ hens was 3.2-, 4.2-, and 1.9-fold higher for Days 6, 11 and 12 respectively, when compared with to ALC+ hens. These results suggest that Salmonella virulence in the gastrointestinal ecology of chickens could be impacted by a combination of low nutrients availability and pH shifts.
7

Performance Analysis of Real-time Heuristic Search Through Search Space Characterization

Huntley, Daniel A Unknown Date
No description available.
8

Correctness and communication in real-time systems

Schneider, Steve A. January 1989 (has links)
No description available.
9

Implementation of Vertical Handoff Algorithm between IEEE802.11 WLAN and CDMA Cellular Network

Narisetti, Mary 31 July 2006 (has links)
Today’s wireless users expect great things from tomorrow’s wireless networks. These expectations have been fueled by hype about what the next generations of wireless networks will offer. The rapid increase of wireless subscribers increases the quality of services anytime, anywhere, and by any-media becoming indispensable. Integration of various networks such as CDMA2000 and wireless LAN into IP-based networks is required in these kinds of services, which further requires a seamless vertical handoff to 4th generation wireless networks. The proposed handoff algorithm between WLAN and CDMA2000 cellular network is implemented. The results of the simulation shows the behavior of the handoff and the time spent in WLAN or CDMA. The number of weak signal beacons determines whether a handoff is required or not. In this algorithm, traffic is classified into real-time and non real-time services.
10

HARQ Packet Scheduling Based on RTT Estimation in LTE Networks

Li, Yi-Wei 15 February 2012 (has links)
In an LTE (Long-Term Evolution) network, HARQ (Hybrid Automatic Repeat reQuest) is used to reduce the error probability of retransmitted packets. However, HARQ cannot guarantee delay constraints for real-time traffic when RBs (Resource Blocks) are allocated improperly. To avoid the retransmitted real-time packets exceeding their delay constraints, we propose an HARQ scheduling scheme based on RTT (Round-Trip-Time) estimation. In this scheme, traffic are classified into real-time and non-real-time queues in which real-time queue are further classified into four sub-queues according to their retransmission times; i.e., the first transmission queue, the first retransmission queue, the second retransmission queue, and the third retransmission queue. For the four real-time queues, we estimate RTT and compute the number of RBs required satisfying the delay constraints. To prevent from starvation of non-real-time traffic, after allocating the RBs for real-time traffic, the remaining RBs are allocated for non-real-time traffic according to their MBR (Minimum Bit Rate). To analyze the proposed scheduling scheme, we build a mathematical model to derive the successful probability of retransmitted packets and the expected value of packet retransmission times. Finally, we compute average packet delay, average packet loss rate, and the throughput for both real-time and none-real-time traffic by varying packet error probability and the delay constraints of real-time traffic.

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