4,570 research outputs found

    Postpartum Mental Health among Young Women

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    Background: A number of studies have highlighted the physical health problems associated with adolescent pregnancy in Saudi Arabia , However there were few studies dealing with the postpartum psychiatric disorders .The study aims to determine the prevalence of postpartum psychological distress and to evaluate the associated risk factors in a sample of primigravid young women in Al Ahsa region, Saudi Arabia. Methods: We assessed the prevalence of postnatal mental health in 190 young mothers attending the maternity hospital using general health questionnaire. We also assessed the relationship between socio-demographic, psychiatric and obstetric risk factors and the mental health. Results: The percent of women with psychological distress was 35.2%. Significant risk of psychological distress was associated with several socio-demographic, psychiatric and obstetric risk factors. Only four items were found to be significant predictors of postpartum psychological distress; low family income, poor husband support, birth of female baby and gestational diabetes. Conclusions: These results highlighted importance of screening for psychological distress and its associated risk factors in the implementation of proper perinatal care for the pregnant Saudi adolescents

    Energy Efficient Multiuser Scheduling: Statistical Guarantees on Bursty Packet Loss

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    In this paper, we consider energy efficient multiuser scheduling. Packet loss tolerance of the applications is exploited to minimize average system energy. There is a constraint on average packet drop rate and maximum number of packets dropped successively (bursty loss). A finite buffer size is assumed. We propose a scheme which schedules the users opportunistically according to the channel conditions, packet loss constraints and buffer size parameters. We assume imperfect channel state information at the transmitter side and analyze the scheme in large user limit using stochastic optimization techniques. First, we optimize system energy for a fixed buffer size which results in a corresponding statistical guarantee on successive packet drop. Then, we determine the minimum buffer size to achieve a target (improved) energy efficiency for the same (or better) statistical guarantee. We show that buffer size can be traded effectively to achieve system energy efficiency for target statistical guarantees on packet loss parameters.Comment: Proc. Physcomnet in conjunction with WIOPT 201

    Optimal Energy Allocation For Delay-Constrained Traffic Over Fading Multiple Access Channels

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    In this paper, we consider a multiple-access fading channel where NN users transmit to a single base station (BS) within a limited number of time slots. We assume that each user has a fixed amount of energy available to be consumed over the transmission window. We derive the optimal energy allocation policy for each user that maximizes the total system throughput under two different assumptions on the channel state information. First, we consider the offline allocation problem where the channel states are known a priori before transmission. We solve a convex optimization problem to maximize the sum-throughput under energy and delay constraints. Next, we consider the online allocation problem, where the channels are causally known to the BS and obtain the optimal energy allocation via dynamic programming when the number of users is small. We also develop a suboptimal resource allocation algorithm whose performance is close to the optimal one. Numerical results are presented showing the superiority of the proposed algorithms over baseline algorithms in various scenarios.Comment: IEEE Global Communications Conference: Wireless Communications (Globecom2016 WC

    Trading Wireless Information and Power Transfer: Relay Selection to Minimize the Outage Probability

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    This paper studies the outage probability minimization problem for a multiple relay network with energy harvesting constraints. The relays are hybrid nodes used for simultaneous wireless information and power transfer from the source radio frequency (RF) signals. There is a trade-off associated with the amount of time a relay node is used for energy and information transfer. Large intervals of information transfer implies little time for energy harvesting from RF signals and thus, high probability of outage events. We propose relay selection schemes for a cooperative system with a fixed number of RF powered relays. We address both causal and non-causal channel state information cases at the relay--destination link and evaluate the trade-off associated with information/power transfer in the context of minimization of outage probability.Comment: IEEE GlobalSiP, 201
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