Optimization of sparse randomly spaced linear antenna array using hybrid iteratively reweighted least squares

Uniformly Spaced Antenna Array (USAA) with large radiating elements is characterized with complex feed network as well as high sidelobes level (SLL) leading to interference and power wastage. To solve these problems, research works have been carried out using different methodologies, to synthesize sparse Randomly Spaced An- tenna Array (RSAA) to reconstruct the desired radiation pattern using fewer radiating elements and suppressed SLL. In this paper, a deterministic Iteratively Reweighted Least Squares (IRLS) algorithm based on the concept of compressed sensing was used to achieve better sparsity through thinning. The SLL was also suppressed using Convex Technique (CT). The performance of the synthesized array was evaluated in terms of sparsity and SLL. Simulation results showed that it has a higher sparsity of 12 elements with SLL of -39.44dB which are 14.29% and 28.72% improvements, respectively compared to previous research work with 14 elements and SLL of -30.64dB

Utilization of Sexual and Reproductive Health Services in Ethiopia--does it affect sexual activity among high school students?

OBJECTIVE: Universal access to Sexual and Reproductive Health (SRH) services for adolescents was added as a target to the revised Millennium Development Goals framework in 2005. However, the utilization of SRH services among adolescents and their sexual activity is not well explored in Ethiopia, with the result that there is no well-designed and sustainable school based intervention for high school students. We aimed to investigate the utilization of sexual and reproductive health services and sexual activity and, to provide evidence based information and recommendations for possible interventions. STUDY DESIGN: A cross-sectional survey was conducted among 1031 female and male high school students aged 14-19 years in Mekelle town, Tigray Region, North Ethiopia. A total of 1031 students participated. Self-administered questionnaire was used. MAIN OUTCOME MEASURES: Utilization of sexual and reproductive health services and sexual activity were investigated using a self-administered questionnaire. RESULTS: One out of five students had used the SRH services in the past year. The primary reason for visiting the SRH services was to receive information. The mean age for the first sexual intercourse was 15.7 and one-quarter of the students had multiple sexual partners. Unwanted pregnancies and abortions were reported by female students. CONCLUSION: SRH services are known and used by students. However, sexual activity at an early age among high school students and unwanted pregnancies and abortions among female students still call for attention. Therefore, providing accurate SRH information on safe sex and enhancing family-student discussion could be a good approach to reach SRH of adolescents

Effect of beneficiation of Harin-Hamza Futuk bentonite for drilling fluid formulation

This research focused on beneficiation and characterization of raw Garin Hamza Futuk (GHF) Bentonite for oil and gas drilling fluid formulation. The FTIR results confirmed that GHF bentonitic clay is rich in montmorillonite mineral noticed at approximately 3620-3630cm-1 stretching band in the higher frequency level. In the lower frequency region, montmorillonite had a strong band at 1024.24 and 1028.09 cm-1 for Sivibration of layered silicates.The X-ray fluorescence (XRF) results showed slight reduction in free silica (Quartz) by about 1%. The SEM images of the beneficiated samples were more dispersed than the raw sample with some large flocs structure confirming their montmorillonitic nature. The optimum amount of poly anionic cellulose (PAC)used for instant drilling fluid formulation was found to be at 2.0 g, while the aged formulation was achieved at 0.8g PAC when compared with the API grade. Hence, GHF bentonite can be used for drilling fluid formulation

Low-Complexity Linewidth-Tolerant Carrier Phase Estimation for 64-QAM Systems Based on Constellation Transformation

A novel three-stage digital feed-forward carrier recovery algorithm based on the transformation of 64-QAM constellation into QPSK is proposed. For 1 dB penalty at BER=1e-2, it can tolerate a linewidth-times-symbol-rate product of 4.5e-5, making it possible to operate 32-Gbaud optical 64-QAM systems with current commercial tunable lasers

Practices and Challenges of Growth Monitoring and Promotion in Ethiopia: A Qualitative Study

The use of growth monitoring and promotion (GMP) has become widespread. It is a potential contributor towards achieving the Millennium Development Goals of halving hunger and reducing child mortality by two-thirds within 2015. Yet, GMP appears to be a prerequisite for good child health but several studies have shown that there is a discrepancy between the purpose and the practice of GMP. The high prevalence of malnutrition in many developing countries seems to confirm this fact. A descriptive qualitative study was carried out from April to September 2011. Focus group discussions and in-depth interviews were conducted amongst mothers and health workers. Data were analyzed using a qualitative content analysis technique, with the support of ATLAS.ti 5.0 software. The results suggest that most mothers were aware of the need for regular weight monitoring while health workers also seemed to be well-aware and to practise GMP according to the international guidelines. However, there was a deficit in maternal knowledge with regard to child-feeding and a lack of basic resources to keep and/or to buy healthful and nutritionally-rich food. Furthermore, the role of the husband was not always supportive of proper child-feeding. In general, GMP is unlikely to succeed if mothers lack awareness of proper child-feeding practices, and if they are not supported by their husbands

The influence of father's child feeding knowledge and practices on children's dietary diversity: a study in urban and rural districts of Northern Ethiopia

Infant and young child feeding has been recognised as an essential element to improve growth of children, especially in developing countries where malnutrition among children and its dire consequences are very prevalent. However, little attention has been paid on the influence of fathers on child feeding practices, although fathers are very important in raising well-adjusted, happy and successful children. Therefore, this study aimed to assess the influence of fathers' child feeding knowledge and practice on children's dietary diversity. A community-based comparative cross-sectional study was conducted among 850 eligible urban and rural house-holds with children of 6-23 months. The father and mother of the child were interviewed on children's dietary diversity and fathers' knowledge and practice of child feeding. Nearly half (46%) of the children in the rural district did not meet the minimum dietary diversity, and in the urban district, the rate was even worse (72%). Grains were the common food group given to the children in both districts, whereas flesh food was the least commonly consumed food group. Additionally, low vitamin A-rich food and other fruit and vegetable consumption seem to be a problem in both districts. Almost all dimensions of fathers' knowledge and practice were significantly related to children's minimum dietary diversity; especially, fathers' knowledge of food groups was an important predictor (P-value <0.001) in both districts. Interventions that focus on the fathers' knowledge of child feeding, especially about food groups, are recommended to improve children's dietary diversity in the study communities

Effectiveness of Digital Back-Propagation and Symbol-Rate Optimization in Coherent WDM Optical Systems

We apply DBP to an experimental WDM system where multisubcarrier transmission provides a 12% reach gain vs. single-carrier. DBP provides further gain for both single- and multisubcarrier systems but significantly underperforms ideal theoretical predictions

Abundant soliton solutions of the modified KdV-KP equation

The precise solutions of the (2+1)-dimensional modified KdV-KP equation are examined in this study. Three reliable methods, namely, the modified auxiliary equation scheme, extended rational sine–cosine methodology, and extended rational sinh–cosh technique, are utilized for the first time to extract multiple soliton solutions for the governing model. These types of solutions have applications in plasma, solid state, neuronal, biological production, and diffusion processes. Graphical simulations of the obtained solutions are included in the form of 3 dimensional surface plots to reveal their physical structure and dynamical features

Theoretical and experimental assessment of nonlinearity mitigation through symbol rate optimization

We investigated the reach increase obtained through non-linearity mitigation by means of transmission symbol rate optimization (SRO). We did this first theoretically and simulatively. We show that for PM-QPSK systems at full-C-band the reach increase may be substantial, on the order of 10%-25%, with optimum symbol rates on the order of 2-to-6 GBaud. We extended the investigation to PM-16QAM, where we found a qualitatively similar effect, although the potential reach increase is typically only about half that of PM-QPSK. We then set up an experiment to obtain confirmation of the theoretical and simulative predictions. We demonstrated a reach increase of 11% in a 19-channel, 128Gbit/s per channel, PM-QPSK experiment, when going from single-carrier per channel to multi-subcarrier (up to 16 subcarriers per channel) transmission. The experiment reached 14,100 km over PSCF, with 110 km spans and EDFA-only amplification. The results matched well the model predictions