Hong Kong University of Science and Technology

About: Hong Kong University of Science and Technology is a education organization based out in Hong Kong, Hong Kong, China. It is known for research contribution in the topics: Population & MIMO. The organization has 20126 authors who have published 52428 publications receiving 1965915 citations. The organization is also known as: HKUST & The Hong Kong University of Science and Technology.

Elucidation of Calcite Structure of Calcium Carbonate Formation Based on Hydrated Cement Mixed with Graphene Oxide and Reduced Graphene Oxide.

Abstract: In this study, the carbonation of Portland cement by direct chemical interaction with graphene oxide (GO) and reduced graphene oxide (rGO) at 7 and 28 days was examined. During the carbonation reaction, the calcium-bearing phases (calcium hydroxide, calcium silicate hydrate, and ettringite) formed calcium carbonate polymorphs, along with amorphous silica gel, gypsum, and alumina gel. These reaction products were examined using XRD (X-ray diffraction), XPS (energy-dispersive spectrometry), and FTIR (Fourier transform infrared). XRD patterns showed that the intensities of the calcium hydroxide and calcium carbonate peaks in the hydrated cement mixed with GO and/or rGO are higher than the corresponding peaks in the hydrated cement without any additives. The morphology of the reaction products was also characterized by SEM (scanning electron microscopy) measurements, which showed that a needle-like phase of calcium carbonate develops on the hydrated cement. The obtained microstructure parameters enabled the development of a more precise carbonation model.

Multiuser subcarrier and bit allocation along with adaptive cell selection for OFDM transmission

Abstract: A dynamic multiuser subcarrier-and-bit allocation algorithm with low computational complexity for wideband OFDM downlink transmission is proposed to exploit the multiuser diversity in this paper. Our objective is to maximize the overall spectral efficiency in terms of the number of bits per subcarrier while simultaneously satisfying the requirements on each user's data rate, bit error rate (BER), and the total transmit power. Our results show that the proposed dynamic subcarrier-and-bit allocation algorithm offers about 6 dB performance gain over OFDM using adaptive modulation with fixed subcarrier allocation. Since outages may occur when users happen to be located near the boundary of the cell, a novel adaptive cell selection scheme is proposed to further reduce the probability of outage. Our results show that the probability of outage can be reduced by one order of magnitude.

3-Dimensional Integration for Interconnect Reduction in for Nano-CMOS Technologies

Abstract: This paper describes a method to integrate non-planar multi-gate CMOS devices in the third dimension. The technology is based on highly scalable multi-gate MOSFET structures which are promising for nano-scale integration. The extension to have active devices placed the third dimension allow significant reduction in the interconnect loading. We have demonstrated the potential of such technology though experimentally fabricated devices as well as detail system level analysis.