Energy-Efficient Route Optimization for Adaptive MPSK-Based Wireless Sensor Networks

We study a certain route configuration problem via optimization theory. We consider the optimal bit error rate (BER) and transmission rate allocations on each hop, subject to overall BER and delay constraints for a designated route. The pivot of the problem lies in the delay constraint, which divides the problem into two cases&#8212;the loose and the tight delay case. In the former, analytical solutions are obtained by applying the Karush-Kuhn-Tucker (KKT) theorem. Specifically, we discover in this case that for a given target BER, the optimum solutions are only related to the hop lengths in the route. When the delay constraint is tight, a mapping can be used to reduce the dimension of the problem by a factor of two; a numerical optimization algorithm has to be used to find the optimum. Simulation results show that by optimally configuring a chosen route, substantial energy savings could be obtained, especially under tight delay constraints. Simulation also reveals that a performance limit is reached as the number of hops increases. A parameter determining this limit is defined, and physical explanations are given accordingly.</p

Energy-Efficient Route Optimization for Adaptive MPSK-Based Wireless Sensor Networks

We study a certain route configuration problem via optimization theory. We consider the optimal bit error rate (BER) and transmission rate allocations on each hop, subject to overall BER and delay constraints for a designated route. The pivot of the problem lies in the delay constraint, which divides the problem into two cases&#8212;the loose and the tight delay case. In the former, analytical solutions are obtained by applying the Karush-Kuhn-Tucker (KKT) theorem. Specifically, we discover in this case that for a given target BER, the optimum solutions are only related to the hop lengths in the route. When the delay constraint is tight, a mapping can be used to reduce the dimension of the problem by a factor of two; a numerical optimization algorithm has to be used to find the optimum. Simulation results show that by optimally configuring a chosen route, substantial energy savings could be obtained, especially under tight delay constraints. Simulation also reveals that a performance limit is reached as the number of hops increases. A parameter determining this limit is defined, and physical explanations are given accordingly

Adaptive Route Configuration for Increased Energy Efficiency in Wireless Sensor Networks

In this paper, we discuss a certain route configuration problem via optimization theory. The problem is potentially relevant for designers of both wireless sensor and wireless ad hoc networks with multihop and link adaptation capability. We consider the optimal bit error rate (BER) and transmission rate allocations subject to overall BER and delay constraints for a designated route. The pivot of the problem lies in the delay constraint, which divides the problem into two cases - the loose delay and the tight delay case. In the former, analytical solutions are obtained by applying the Karush-Kuhn-Tucker (KKT) theorem. Specifically, we discover in this case that for a given target BER, the optimum solutions are only related to the hop lengths in the route. When the delay constraint is tight, there exists a mapping which can be used to reduce the dimension of the problem by a factor of two; however, a numerical optimization algorithm has to be used to find the optimum. The problem can however be shown to be a convex optimization problem, which ensures that any local minimum will be global. Simulation results show that by optimally configuring a chosen route, substantial energy savings could be obtained, especially under tight delay constraints

Protecting the orbital angular momentum of photonic qubits using quantum error correction

Photons with orbital angular momentum provide an infinite-dimensional Hilbert space. Here, we study the propagation of such photons in atmospheric turbulence and obtain the Kraus operator representation for the decoherence-induced noise. We apply quantum error correction to suppress this decoherence. Specifically, we treat correction as an optimization problem in which the distance between the actual channel and the desired channel is minimized. This method provides significant channel fidelity enhancement irrespective of the turbulence strength

Self-Rated Health Status and Subjective Health Complaints Associated with Health-Promoting Lifestyles among Urban Chinese Women: A Cross-Sectional Study

<div><p>Objective</p><p>This study aimed to investigate whether self-rated health status (SRH) and subjective health complaints (SHC) of urban Chinese women are associated with their health-promoting lifestyles (HPL).</p><p>Methods</p><p>We conducted a cross-sectional study on 8142 eligible Chinese participants between 2012 and 2013. Demographic and SHC data were collected. Each subject completed the SRH questionnaire and the Chinese version of the Health-Promoting Lifestyle Profile-II (HPLP-II). Correlation and binary regression analyses were performed to examine the associations of SRH and SHC with HPL.</p><p>Results</p><p>Both SRH and HPL of urban Chinese women were moderate. The most common complaints were fatigue (1972, 24.2%), eye discomfort (1571, 19.3%), and insomnia (1542, 18.9%). Teachers, highly educated subjects and elderly women had lower SRH scores, while college students and married women had better HPL. All items of HPLP-II were positively correlated with SRH (r = 0.127-0.533, <i>P</i> = 0.000) and negatively correlated with SHC to a significant extent (odds ratio [OR] = 1.40-11.37).</p><p>Conclusions</p><p>Aspects of HPL, particularly stress management and spiritual growth, are associated with higher SRH and lower SHC ratings among urban Chinese women. Physical activity and health responsibility are additionally related to reduced fatigue and nervousness. We believe that these findings will be instrumental in encouraging researchers and urban women to adopt better health-promoting lifestyles with different priorities in their daily lives.</p></div

Sociodemographic characteristics and subjective health complaints of participants.

<p>Sociodemographic characteristics and subjective health complaints of participants.</p

Sociodemographic characteristics and subjective health complaints of participants.

<p>Sociodemographic characteristics and subjective health complaints of participants.</p

Correlation of health-promoting lifestyle profiles with subject characteristics (n = 8142).

<p>r, coefficient of correlation of health-promoting lifestyle profiles with marital status derived through point biseral correlation analysis (Single/divorced,1; Married, 2); with job position and education level through point multivariate correlation analysis (college students, 1; teachers, 2; civil servants, 3; workers, 4 and for education level: compulsory school, 1; high school graduate, 2; university/college degree, 3) with age or body mass index through Spearman’s correlation analysis.</p><p>*<i>P</i><0.05</p><p>**<i>P</i><0.01</p><p>***<i>P</i><0.001 indicate significant correlations between health-promoting lifestyle profiles and subject characteristics.</p><p>Correlation of health-promoting lifestyle profiles with subject characteristics (n = 8142).</p