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Articles 1 - 4 of 4
Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering
Energy-Efficient, Flow-Specific Medium Access Using Preamble Sampling, T. Owens Walker Iii, Murali Tummala, John Mceachen
Energy-Efficient, Flow-Specific Medium Access Using Preamble Sampling, T. Owens Walker Iii, Murali Tummala, John Mceachen
U.S. Navy Research
Current wireless sensor network applications face challenging power constraints that demand low duty cycles. In this paper, we propose an energy-efficient, flow-specific medium access scheme that is capable of achieving low duty cycles while taking advantage of the performance improvements available through a flow-specific medium access approach. The scheme is based on an adaptive sleep and wake cycle that responds to changes in both contention and non-contention traffic loads through the use of preamble sampling. A preamble sampling probability parameter is introduced to manage the trade-off between energy efficiency and network throughput and delay performance. A performance analysis is conducted …
Model For Virtual Physical Layer Communication Over Deployed Wireless Sensor Networks, Thomas Childers, Yow Thiam Poh, John Mceachen, Murali Tummala
Model For Virtual Physical Layer Communication Over Deployed Wireless Sensor Networks, Thomas Childers, Yow Thiam Poh, John Mceachen, Murali Tummala
U.S. Navy Research
A method for file transfer utilizing forward error correction (FEC) to pass traffic over deployed wireless sensor networks is studied. The entire wireless sensor network is modeled as an error-prone virtual physical link. Previous work in the area of terminal communication across the sensor network is expanded upon to include file transfer in order to provide a more capable channel and a basis for testing the performance obtained through erasure coding. The results of the FEC implementation are examined using multiple sensor network configurations. While the error correction method proved effective, larger topologies presented congestion issues due to the sensors’ …
Characterization Of Electrochemically Active Bacteria Utilizing A High-Throughput Voltage-Based Screening Assay, Justin C. Biffinger, Meghann Ribbens, Bradley Ringeisen, Jeremy Pietron, Steven Finkel, Kenneth Nealson
Characterization Of Electrochemically Active Bacteria Utilizing A High-Throughput Voltage-Based Screening Assay, Justin C. Biffinger, Meghann Ribbens, Bradley Ringeisen, Jeremy Pietron, Steven Finkel, Kenneth Nealson
U.S. Navy Research
Metal reduction assays are traditionally used to select and characterize electrochemically active bacteria (EAB) for use in microbial fuel cells (MFCs). However, correlating the ability of a microbe to generate current from an MFC to the reduction of metal oxides has not been definitively established in the literature. As these metal reduction assays may not be generally reliable, here we describe a four- to nine-well prototype high throughput voltage-based screening assay (VBSA) designed using MFC engineering principles and a universal cathode. Bacterial growth curves for Shewanella oneidensis strains DSP10 and MR-1 were generated directly from changes in open circuit voltage …
Simultaneous Analysis Of Physiological And Electrical Output Changes In An Operating Microbial Fuel Cell With Shewanella Oneidensis, Justin C. Biffinger, Ricky Ray, Brenda J. Little, Lisa A. Fitzgerald, Meghann Ribbens, Steven E. Finkel, Bradley R. Ringeisen
Simultaneous Analysis Of Physiological And Electrical Output Changes In An Operating Microbial Fuel Cell With Shewanella Oneidensis, Justin C. Biffinger, Ricky Ray, Brenda J. Little, Lisa A. Fitzgerald, Meghann Ribbens, Steven E. Finkel, Bradley R. Ringeisen
U.S. Navy Research
Changes in metabolism and cellular physiology of facultative anaerobes during oxygen exposure can be substantial, but little is known about how these changes connect with electrical current output from an operating microbial fuel cell (MFC). A high-throughput voltage based screening assay (VBSA) was used to correlate current output from a MFC containing Shewanella oneidensis MR-1 to carbon source (glucose or lactate) utilization, culture conditions, and biofilm coverage over 250 h. Lactate induced an immediate current response from S. oneidensis MR-1, with both air-exposed and anaerobic anodes throughout the duration of the experiments. Glucose was initially utilized for current output by …