Simplified Compute-and-Forward and Its Performance Analysis

The compute-and-forward (CMF) method has shown a great promise as an innovative approach to exploit interference toward achieving higher network throughput. The CMF was primarily introduced by means of information theory tools. While there have been some recent works discussing different aspects of efficient and practical implementation of CMF, there are still some issues that are not covered. In this paper, we first introduce a method to decrease the implementation complexity of the CMF method. We then evaluate the exact outage probability of our proposed simplified CMF scheme, and hereby provide an upper bound on the outage probability of the optimum CMF in all SNR values, and a close approximation of its outage probability in low SNR regimes. We also evaluate the effect of the channel estimation error (CEE) on the performance of both optimum and our proposed simplified CMF by simulations. Our simulation results indicate that the proposed method is more robust against CEE than the optimum CMF method for the examples considered.Comment: Submitted to IET Communications, 29 pages, 7 figures, 1 table, latex, The authors are with the Wireless Research Laboratory (WRL), Department of Electrical Engineering, Sharif University of Technology, Tehran, Ira

Fully Coupled Numerical Modelling of Wave-Current-Mud Interaction by Finite Volume Method

Experimental and Computational Hydraulic

Robust Successive Compute-and-Forward over Multi-User Multi-Relay Networks

This paper develops efficient Compute-and-forward (CMF) schemes in multi-user multi-relay networks. To solve the rank failure problem in CMF setups and to achieve full diversity of the network, we introduce two novel CMF methods, namely, extended CMF and successive CMF. The former, having low complexity, is based on recovering multiple equations at relays. The latter utilizes successive interference cancellation (SIC) to enhance the system performance compared to the state-of-the-art schemes. Both methods can be utilized in a network with different number of users, relays, and relay antennas, with negligible feedback channels or signaling overhead. We derive new concise formulations and explicit framework for the successive CMF method as well as an approach to reduce its computational complexity. Our theoretical analysis and computer simulations demonstrate the superior performance of our proposed CMF methods over the conventional schemes. Furthermore, based on our simulation results, the successive CMF method yields additional signal-to-noise ratio gains and shows considerable robustness against channel estimation error, compared to the extended CMF method.Comment: 44 pages, 10 figures, 1 table, accepted to be published in IEEE Trans. on Vehicular Tec

Depression Symptoms , Acculturation, Needing Care, and Receiving Care: A Study of Adolescents Living in California

Background: The objectives of this study are 1) to depict the prevalence of moderate depressive symptoms (MDS) in adolescents living in California, 2) to examine the role of acculturation in reported MDS, and 3) to identify any relationship between acculturation, “needing emotional help,” and “receiving psychological or emotional counseling,” as reported by adolescents with MDS. Methods: We analyzed data from a cross-sectional population-based telephone survey for adolescents who completed the California Health Interview Survey (CHIS) in 2007, 2009, and 2011-2012. The primary predictor variable was level of acculturation. Outcome variables were 1) the presence of MDS, 2) whether participants needed help with emotional problems, and 3) whether they had received psychological or emotional counseling. Results: Of the sample (n = 9816), 6.0% had MDS; 50% of these reported needing help for emotional problems, and 30% reported receiving psychological/emotional counseling. Multivariate analysis that included the interaction effects of race/ethnicity and acculturation showed that the latter was not associated with any of the outcome variables. However, Latino adolescent with MDS and moderate acculturation were less likely to report needing help for psychological/emotional problems, compared to their White counterparts with higher acculturation. Conclusion: Our findings suggest disparities in reporting depression symptoms and receiving psychological/emotional help are not driven by adolescents’ acculturation levels. However, more studies are needed to clarify what cultural factors facilitate or inhibit moderately acculturated Latino adolescents from reporting needing help for psychological/emotional problems

Effect of some Ecological Factors on Quantity and Quality of the Essential Oils of Zhumeria majdae

Zhumeria majdae Rech.f. & Wendelbois the medicinal, endomic and endangered plant that has been distributed in the south of Iran. This plant is seen on very sharp slope of mountains at 520-1450 meters altitude of sea level. It has noticed by natives and is used for digestion painful as swelling, diarrhea, stomatchache and coolness. In this research, the leaves of plant and soil samples were collected from different localities (Geno, Sarchahan and Tangezagh mounts). The plant materials were hydri-distilled in order to obtain their essential oils. The oils were analyzed by capillary GC and GC/MS. The results showed that with increasing of  height, Ca+², Mg+², HCO3¯,  Na+, EC, O.C.%, sand% contents and also with decreasing of rainfall, moisture, temperature, K+and neutralized materials, oil yield and componentnumber of essential oils of Z. majdae would have decreased. Constituents as Linalool, Limonene, α-Pinene, Octan-3-one, Myrcene, Terpinolene and trans-Linalool oxide will increased and constituents as Camphor, Geraniol, Neral, Geranial, Thymul, Terpinene, β-Elemene, β- Bizabulene will decreased. Therefore, height is effective on quantity and quality of the essential oils of Z.majdae

Sexual diversity of red algae using isomorphic generations of Gracilaria corticata in the northern Persian Gulf and Oman Sea

In conformity with the sex determination of Gracilaria corticata in the Persian Gulf and Oman Sea, a total of 41 samples were collected from two stations of Bostaneh region (northern Persian Gulf, 54° 38´ E / 26° 30´ N) and Lipar regions (northern Oman Sea, 60° 49´ E / 25° 15´ N). The specimens were cultured in PES media for observing the different life stages. The anatomical structures of thallus were taken into consideration. The diploid tetrasporophytes and spermatangia in thallus of male’s gametophytes; and Carpospore and cystocarps of female were determined. Due to DNA extraction, the parasites and epiphytes were cleaned and then the under growing sections were sectioned using liquid nitrogen. After extraction of DNA, by using 20 different primers according to ISSR molecular indicator, the sex diversity and genetic diversity of populations were studied; and four primers were selected ultimately. The obtained results were analyzed by GenAlex and PopGen softwares. In total, 74 bands, all polymorphisms, were propagated. According to PIC index, polymorphism separation of primer C (0.33) was higher than other primers. The Marker Index was measured between 4.48 and 6.51 with mean Shannon’s index of 0.46. The genetic similarity amongst algae was 96%. The genetic diversity inter and intra populations had significant differences of which 83% of total diversity was related to the intra diversity and 17% was related to inter diversity populations. The highest genetic distance belonged to the specimens 5 (Bostaneh) and 35 (Lipar), and it indicated the inter populations diversity in addition to intra population. As an overall conclusion, these populations can be considered as broodstocks for hybrid production for further species breeding and also to attain the maximum heterosis in adaptation with environment. In Ward clustering analysis, the dendrograms showed 5 different clusters in genetic distance of 12.18 of isomorphic phases. The PCA analysis as a complementally method was used for attest the findings. In this research, the ISSR primers could determine the male and female gametophytes and diploid tetrasporophytes in which the primer A (bands of 1200 & 1700 bp) specific for diploid tetrasporophyte and band of 300 bp specific for male were produced. The primer C showed the bands of 820 & 900 bp for diploid tetrasporophyte, and 500 bp for female gametophyte. The primer AB (990 bp) for male, 520 bp for female and 1600 & 1900 bp for diploid tetrasporophyte were specified. The primer ABC showed the specific band of 1100 bp for male; 500 bp for female; and 1200 & 1500 bp for diploid tetrasporophytes