Real-time Optimal Resource Allocation for Embedded UAV Communication Systems

We consider device-to-device (D2D) wireless information and power transfer systems using an unmanned aerial vehicle (UAV) as a relay-assisted node. As the energy capacity and flight time of UAVs is limited, a significant issue in deploying UAV is to manage energy consumption in real-time application, which is proportional to the UAV transmit power. To tackle this important issue, we develop a real-time resource allocation algorithm for maximizing the energy efficiency by jointly optimizing the energy-harvesting time and power control for the considered (D2D) communication embedded with UAV. We demonstrate the effectiveness of the proposed algorithms as running time for solving them can be conducted in milliseconds.Comment: 11 pages, 5 figures, 1 table. This paper is accepted for publication on IEEE Wireless Communications Letter

Chain: A Dynamic Double Auction Framework for Matching Patient Agents

In this paper we present and evaluate a general framework for the design of truthful auctions for matching agents in a dynamic, two-sided market. A single commodity, such as a resource or a task, is bought and sold by multiple buyers and sellers that arrive and depart over time. Our algorithm, Chain, provides the first framework that allows a truthful dynamic double auction (DA) to be constructed from a truthful, single-period (i.e. static) double-auction rule. The pricing and matching method of the Chain construction is unique amongst dynamic-auction rules that adopt the same building block. We examine experimentally the allocative efficiency of Chain when instantiated on various single-period rules, including the canonical McAfee double-auction rule. For a baseline we also consider non-truthful double auctions populated with zero-intelligence plus"-style learning agents. Chain-based auctions perform well in comparison with other schemes, especially as arrival intensity falls and agent valuations become more volatile

Shape modeling and boulder napping of asteroid 1992 UY4.

In August 2005, the near-Earth Asteroid 1992 UY4 made a close flyby, coming within 0.04 au of our planet. Between the dates of 1-10 August 2005, it was observed via delay-Doppler radar imaging by the Arecibo Observatory (2380 MHz, 13 cm) and the DSS-14 antenna at the Goldstone Deep Space Communications Complex (8560 MHz, 3.5 cm). The images achieve a resolution as fine as 7.5 m/pixel and reveal a lumpy and modestly asymmetric object. The images also revealed the presence of numerous large boulders/blocks on the surface of 1992 UY4. By using the modeling software SHAPE, which is standard in the field of asteroid radar imaging, and by using a visual examination of the models vs. radar images and the chi-square statistic as a relative (but not absolute) probability metric, I found two potential pole directions: one at lambda = 285 ±10 deg., beta = -80 ±10 deg.,and one at lambda = 110 ± 10 deg., beta = 75 ± 10 deg., the mirror direction. They represent a north-south ambiguity: 1992 UY4 may rotate either prograde or retrograde. I find that the models for the first pole direction better match the observations and I conclude that 1992 UY4 is most likely a retrograde rotator. I identified 18 boulder candidates on 1992 UY4’s surface based on independent visual inspection of the images by Dr. Michael Busch, myself, and standard astronomical image statistics. Their distribution is concentrated in those longitudes that were seen in multiple observations from Arecibo. There are few boulders on the edges of Arecibo’s field of view, but this is likely observing bias. With the available data and without more complex modeling and statistical techniques, I cannot determine if boulders are uniformly distributed across the surface of 1992 UY4 or not. Further observations would be needed to map the rest of the asteroid. Unfortunately, there are no upcoming opportunities for future ground-based radar observations, since 1992 UY4 will not pass as near to Earth as it did in 2005 for the next several hundred years. However, thanks to my study of 1992 UY4, in addition to details about the asteroid itself, I have enabled the improvement of its trajectory