1. |
- Phu, Vu Dinh, et al.
(författare)
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Ventilator-associated respiratory infection in a resource-restricted setting: impact and etiology
- 2017
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Ingår i: Journal of Intensive Care. - : BioMed Central (BMC). - 2052-0492. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Ventilator-associated respiratory infection (VARI) is a significant problem in resource-restricted intensive care units (ICUs), but differences in casemix and etiology means VARI in resource-restricted ICUs may be different from that found in resource-rich units. Data from these settings are vital to plan preventative interventions and assess their cost-effectiveness, but few are available.
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2. |
- Duong, Quang Trung, et al.
(författare)
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On The Symbol Error Probability of Distributed-Alamouti Scheme
- 2009
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Ingår i: Journal of Communications. - : Academy Publisher. - 1796-2021 .- 2374-4367. ; 4:7, s. 437-444
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Tidskriftsartikel (refereegranskat)abstract
- Taking into account the relay’s location, we analyze the maximum likelihood (ML) decoding performance ofdualhop relay network, in which two amplify-and-forward (AF) relays employ the Alamouti code in a distributed fashion. In particular, using the well-known moment generating function (MGF) approach we derive the closed-form expressions of the average symbol error probability (SEP) for M-ary phase-shift keying (M-PSK) when the relays are located nearby either the source or destination. The analytical result is obtained as a single integral with finite limits and the integrand composed solely of trigonometric functions. Assessing the asymptotic characteristic of SEP formulas in the high signal-to-noise ratio regime, we show that the distributed-Alamouti protocol achieves a full diversity order. We also perform the Monte-Carlo simulations to validate our analysis. In addition, based on the upper bound of SEP we propose an optimal power allocation between the first-hop (the source-to-relay link) and second-hop (the relay-to-destination link) transmission. We further show that as the two relays are located nearby the destination most of the total power should be allocated to the broadcasting phase (the first-hop transmission). When the two relays are placed close to the source, we propose an optimal transmission scheme which is a non-realtime processing, hence, can be applied for practical applications. It is shown that the optimal power allocation scheme outperforms the equal power scheme with a SEP performance improvement by 2-3 dB.
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3. |
- Duong, Quang Trung, et al.
(författare)
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Symbol Error Probability of Distributed-Alamouti Scheme in Wireless Relay Networks
- 2008
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Konferensbidrag (refereegranskat)abstract
- In this paper, we analyze the maximum likelihood decoding performance of non-regenerative cooperation employing Alamouti scheme. Specifically, we derive two closed-form expressions for average symbol error probability (SEP) when the relays are located near by the source or destination. The analytical results are obtained as a single integral with finite limits and an integrand composed solely of trigonometric functions. Assessing the asymptotic (high signal-to-noise ratio) behavior of SEP formulas, we show that the distributed-Alamouti codes achieves a full diversity order. We also perform Monte-Carlo simulations to validate the analysis.
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