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The genome of the nematode Caenorhabditis elegans shows far-reaching similarities to that of humans. C. elegans is therefore considered as a powerful model organism in biological research related to humans, for instance for the study of human diseases. Such studies are often based on high-resolution imaging of dynamic biological processes in the worm body tissues, requiring reliable immobilization...
Data mining has recently drawn a lot of interests as an effective way of generating a concept map in an adaptive learning system that provides students with the personalized learning guidance. Even with significant progresses witnessed in this field, the data mining-based concept map generation needs further improvement both in accuracy and complexity before it can be employed in actual education...
Recently, high thermally conductive polymers have emerged as low cost and energy efficient alternatives to traditional use of metals in heat transfer applications. Here, we present development of ultra-high molecular weight polyethylene (UHMWPE) thin films with high thermal conductivity. The fabrication platform is based on a sol-gel process followed by mechanical drawing. After gel formation and...
Electro-Optic (EO) image sensors exhibit the properties of high resolution and low noise level, but they cannot reflect information about the temperature of objects and do not work in dark environments. On the other hand, infrared (IR) image sensors exhibit the properties of low resolution and high noise level, but IR images can reflect information about the temperature of objects all the time. Therefore,...
The underwater acoustic (UWA) communication has been regarded as one of the most challenging wireless communications due to the unique properties, such as limited bandwidth, extended multipath delay, medium inhomogeneities, rapid time-variation and large Doppler shifts. Cooperative relaying technique is a promising technique to provide high rate data transmission. However, literature on cooperative...
The underwater acoustic (UWA) communication has been regarded as one of the most challenging wireless communications due to the unique properties, such as limited bandwidth, extended multipath delay, medium inhomogeneities, rapid time-variation and large Doppler shifts. Cooperative relaying technique is a promising technique to provide high rate data transmission. However, literature on cooperative...
Wind blowing over the sea surface generates many dramatic effects. One of the most important effects is bubbles generated by breaking waves, which has major effects on high frequency acoustic propagation, sound speed profile and ambient noise due to the sound scattering and absorption properties of a thin layer of bubbles. In this paper, on one hand, we analyze several important properties of bubbles...
In this paper, we propose a dynamic power allocation scheme for a single-relay network based on orthogonal frequency division multiplexing (OFDM) modulation with limited feedback.We consider an Amplify-and-Forward (AF) cooperative diversity model, where one source node communicates with one destination node assisted by one half duplex relay. The power allocation scheme employs a codebook of quantized...
Adaptive bit and power loading is a constraint optimization problem with generally two cases of practical interest, where the objectives are the achievable data rate maximization (RM) and system margin maximization (MM) \cite{Ni-2008}. In this paper, we propose a different optimization model for underwater acoustic (UWA) channels, which is achieved by two algorithms: one is the bandwidth-efficient...
In orthogonal frequency division multiplexing (OFDM) underwater acoustic (UWA) communications, some subcarriers may be subject to deep fading. If the channel state information (CSI) is available at the transmitter, adaptive transmission techniques can be applied to mitigate the deep fading effect and increase the system's overall performance. Therefore, it is more valuable to analyze the UWA channel...
Wind blowing over the sea surface generates many dramatic effects. One of the most important effects is bubbles generated by breaking waves, which can have a major effect on high frequency acoustic propagation, sound speed profile and ambient noise due to the sound scattering and absorption properties of a thin layer of bubbles. In this paper, on one hand, we analyze several important properties of...
In the orthogonal frequency division multiplexing (OFDM) underwater acoustic (UWA) communications, some subcarriers may be subject to a deep fading. If the channel state information (CSI) is available at the transmitter, adaptive transmission techniques can be applied to mitigate deep fading effect and increase the overall system performance. Since most practical systems only obtain partial CSI at...
How to achieve high speed, large capacity and bandwidth-efficient digital communication in shallow water conditions is challenging work. Recently, Orthogonal frequency division multiplexing (OFDM) has received considerable attention for UWA communication. In this paper, the authors investigate time-varying channel impulse responses with different transceiver moving speeds. For this channel model,...
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