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A mobile ad hoc network (MANET) is a dynamic communication network formed by a collection of autonomous mobile nodes. A MANET offers a cost-effective solution for communications in areas where infrastructure is unavailable, e.g. disaster recovery situations and military applications. It especially suits the needs of the so-called airborne Internet, where(More)
Laser communication using free-space optics is an important element of the proposed US Department of Defense (DoD) Transformational Communication System. It offers data rates on the order of several Gigabits per second, resists electromagnetic jamming and interference, and enjoys low probability of intercept and detection. This paper describes an(More)
This paper investigates the ability of a mechanical gimbal to perform alignment and tracking of a free-space optical communications link between a ground station and an unmanned aerial vehicle. The repeatability and accuracy of a mechanical gimbal are experimentally analyzed in order to generate probability distribution functions for the gimbal's(More)
Medium access control (MAC) is critical for vehicular ad hoc networks (VANET). A real commercial VANET system has not come into the market. Different MAC schemes have been proposed to attempt to achieve the expected performance, such as bounded delay, high packet reception rate, security, etc. Space Division Multiple Access (SDMA) is one of the VANET MAC(More)
Free-space optic (FSO) technology transmits information using a modulated light beam traveling through the atmosphere. In certain situations, when compared with wireless communication, it proves to be more effective by providing higher data rates at reduced size and cost. Current FSO technology transmits data, video, and voice communications at a bandwidth(More)
This paper investigates the performance of R-ALOHA protocol in a mobile wireless environment such as an intervehicle communication (IVC) environment in which Rayleigh fading and capture effects were considered. A Monte Carlo approach modeling the R-ALOHA system in both transient and steady state was constructed to examine the system stabilization time (SST)(More)
With a growing number of vehicles entering roadways, it is important to take the initiative to decrease the number of collisions occurring on them. Intersections, in particular, are notorious for collisions. Unfortunately, due to the complexity of human driver behavior, there is limited technology capable of addressing this problem today. In rural areas,(More)
The paper presents a novel method to detect and count dead and live hepatocytes (liver cells) within clusters. The new method distinguishes single cells from clusters in digital microscopic images based on cell shape rather than size. The new method shows an improvement when compared to an earlier algorithm, especially in images where cells have varying(More)
Inter-vehicle communication is an essential part of any intelligent transportation system (ITS). It allows vehicles to share surrounding road traffic information to support safe driving and road traffic management. Current systems use spread spectrum (SS) techniques: direct sequence (DS) or frequency hopping (FH). This paper proposes an implementation of a(More)
This paper demonstrates a successful application of wavelength division multiplexing (WDM) to the avionics environment to support analog RF signal transmission. We investigate the simultaneous transmission of four RF signals (channels) over a single optical fiber. These four analog channels are sequentially multiplexed and demultiplexed at different points(More)