188 research outputs found
Cluster-Based Cell-Free Massive MIMO Systems: A Novel Framework to Enhance Spectral Efficiency with Low Complexity
The issue of diminished spectral efficiency (SE) of the downlink (DL)
transmission in distributed cell-free massive MIMO (CF-mMIMO) systems poses a
significant challenge in terms of user equipment (UE) performance when compared
to their centralized CF-mMIMO counterparts. The primary root cause of this
issue can be attributed to the reduced efficacy of distributed precoders, which
are devised using local channel state information (CSI) in distributed systems.
This reduced efficacy becomes particularly pronounced in terms of interference
mitigation when compared to centralized precoders. To address this issue, this
paper proposes a novel architectural framework for CF-mMIMO systems, referred
to herein as the "cluster-based structure." Within this innovative structure, a
hybrid amalgamation of centralized and distributed configurations is employed,
complemented by the introduction of a unique cluster arrangement for the access
points (APs) within the network. In this design, the CSI of APs within each
cluster is collectively shared within a local processor unit. Consequently, by
harnessing this enhanced repository of local channel information, local
precoders are formulated, which facilitate more effective interference
mitigation with reduced computational complexity compared to the centralized
approach. This approach ultimately results in a significantly augmented SE when
contrasted with the distributed architecture. The simulation results
unequivocally demonstrate that within the cluster-based framework, the optimal
SE for the network is attained when utilizing four clusters in conjunction with
the MMSE precoding technique, leading to a notable reduction in computational
complexity exceeding 85%. Importantly, this approach surpasses the SE
performance of the centralized structure
Synthese und Untersuchung von funktionalisierten Nanopartikeln und deren Anwendung in der Krebstherapie und -diagnose
[no abstract
Study of the bactericidal and bacteriostatic effects of olive oil, sesame oil and their synergism on Pseudomonas aeruginosa in vitro
Background and aims: Nosocomial infections are common problems in developing and developed countries. One of the pathogens that causes these infections is Pseudomonas aeruginosa. According to the antibiotical resistance of this bacteria, It is essential to find new treatments like new herbal medicine. This study was aimed to determine in vitro antibacterial effects of sesame oil, olive oil and their synergism on P. aeruginosa. Methods: In this experimental study, first, olive oil and sesame oil were obtained by cold-pressing assay. Then, P.aeruginosa ATCC 27853 was prepared from Iranian Research Organization for Science and Technology. Oils and their mixture with the same proportion were made in concentrations from 2 to 1024 mg/ml and the antibacterial character of these oils on P.aeruginosa was investigated by broth micro dilution method and then the amounts of the MIC and the MBC were demonstrated. Results: The MIC of olive oil, sesame oil and their synergism on P.aeruginosa were reported; 16 mg/ml, 128 mg/ml and 128 mg/ml and the MBC of these oils were indicated; 64 mg/ml, 512 mg/ml and 512 mg/ml, respectively. Conclusion: This study showed that sesame oil, olive oil and their synergism can inhibit bacterial growth. Olive oil has more antibacterial effect on this bacteria than sesame oil and their synergism. So, we conclude that there was no synergistic effect in these oils
The Measurement of Height Via 3D Scans of the Seventh Cervical Vertebra in Iranian Adults
Background: The cervical vertebrae are more durable than other skeletal components, and maybe the only remains of a deceased, and their role in determining the height of the deceased has been underestimated. The present study investigated the role of linear differential dimensions of the seventh cervical vertebrae in determining the height of the Iranian adult population using CT scans.Methods: In this cross-sectional study, height were evaluated by 10 indices of the seventh cervical vertebra. The indices were obtained through a CT scan of 66 adult patients, ≥18 years of age, who referred to Rasoul Akram and Firoozgar hospitals for spine CT scan. The sampling method was random, and the study was performed during the first six months of 2018. Results: Four indices of the Length of the Inferior Facets) LIF, (Length of the Inferior Surface of the Vertebral Body) LIVB, (Width of the Inf surface of the Vertebral Body) WIVB, (Length of Spinous Process ) LSP. were statistically significant differences.Conclusion: The results of this study show the accuracy of linear dimensions of the seventh cervical vertebrae for determining height from skeletal remains in the Iranian adult population
Made to measure: Easy Synthesis and Characterization of Nanocomposites with Tailored Functionalities for Chemistry Education
By adding nanoparticles to classical polymer systems, new functional materials with tailored properties can be obtained. The great variety of possibilities opens up just as many interesting fields of application for industry and science. Following on from this, this article will present how the classical educational subject area of polymers can be extended by a current research context. In a series of experiments, students are using inexpensive chemicals and simple materials from the hardware store to produce nanocomposites that have a much greater hardness or antimicrobial activity than polymers alone. Their properties can then be investigated using a simple test method. Overall, it will be illustrated, that the combination of polymer chemistry and nanotechnology offers a variety of learning opportunities and questions with curricular relevance for schools and student laboratories
Estimating Stature and Gender by the Length of the Third, Fourth, and Fifth Fingers of Dominant Hand in Iranian Adults
Background: Stature and gender are essential parameters of forensic anthropology. Moreover, their estimation is critical for medico-legal investigations to identify unknown remains. The present study aimed to estimate stature and gender by the anthropometric dimensions of the Iranian population’s third, fourth, and fifth fingers.Methods: In this cross-sectional study, 199 individuals (99 men & 100 women) were included. Individuals’ demographic information was recorded. A caliper measured the length of the fingers. An anthropometer was used for the measurement of stature. The obtained data were analyzed using SPSS. A multivariate linear regression test was used to predict the stature of individuals based on finger length.Results: In males and females, a solid and positive direct relationship was observed between the length of the third, fourth, and fifth fingers of the hand with the stature of individuals and between the length of the fingers with each other. In the coefficient table of the regression model of this study, in males, the length of the fingers was not predictive of stature, and only the length of the third finger in females had a predictive effect on stature.Conclusion: According to the obtained results, stature is predictable in women through the third finger length using the derived regression equation
The Credibility of Cephalogram Parameters in Gender Identification From Medico-Legal Relevance Among the Iranian Populatio
Background: Normal cephalogram parameters seem to be gender discriminative and thus applicable in forensic medicine. We assessed validity of cephalogram parameters in gender identification among the Iranian population.Methods: This cross-sectional study was conducted on 75 Iranian men and 75 Iranian women aged 25 to 54 years. On their first admission, the physicians requested for simple lateral skull X-ray for all participants.Results: Using area under the ROC curve, gonion-gonion index (AUC=0.741) and vertex- mention index (AUC=0.697) had a moderate value to discriminate male from female gender, while other parameters lacked enough power to differentiate gender. The best cut-off point in gonion-gonion index for discriminating male from female gender was 103.75 with a sensitivity of 74.7% and a specificity of 65.3%. Also, the best cut-off value for vertex-mention index to differentiate two genders was 244.75 with a sensitivity of 74.7% and a specificity of 62.7%. By considering two parameters of gonion-gonion and vertex-mention, it is possible to differentiate males from females with a sensitivity of 82.6% and a specificity of 71.8%.Conclusion: The two gonion-gonion and vertex-mention indices on cephalogram are applicable for gender discrimination
Influence of television programs genre on violent behaviour among young children
The purpose of this study was to examine the relationship between television program genre and aggression behaviour in primary school students. The results of the survey revealed a significant relationship between watching movies with action genre and aggression level among students (p<0.05). Finding indicated that there was no difference between mean of aggression level among children who interested in particular type of TV programs, except animation which showed a significant difference (p<0.05). In conclusion current study provides additional evidence to support that content of television programs particularly its genre is very important in shaping the children behavior. As a new perspective, focus on genre as an important element in producing of television programs could be helpful for authorities
Estimation of Gender and Age Based on Three-dimensional Computed Tomography Scan Indices of the Twelfth Thoracic Vertebrae and the First and Fifth Lumbar Vertebrae in Iranian Adults
Background: Gender identification is a crucial starting point in creating a biological profile for human skeletal remains because it reduces the number of possible matches by 50%. The vertebrae (especially the chest and back) can also be some of the best-preserved skeletal elements in some areas of forensics and archeology. In the present study, gender and age were assessed based on the measurement of three-dimensional computed tomography (CT) scan indices of the Twelfth thoracic (T12) vertebrae and the first and fifth lumbar (L1 and L5) vertebrae in Iranian adults.Methods: The present study was a descriptive study carried out on 200 participants over 18 years of age in 2020. Individuals measuring thoracic and lumbar vertebrae diameters (T12 and first and fifth lumbar vertebrae) by three-dimensional computed tomography (CT) scan (Toshiba, Japan, 16-Slice) with multiplanar reconstruction (MPR) and volume rendering were placed in two sagittal and horizontal sections.Results: The mean age of male and female participants was 34.62±9.63 years and 34.10±9.70 years, respectively, which were not significantly different (P=0.789). The present study showed that the mean indices for T12, L1 and L5 vertebrae were significantly higher in males (P>0.05). The results also showed that T12, L1, and L5 indices of nuts are not good predictors for age estimation.Conclusion: Based on the results, the indices of the T12 vertebrae and the L1, and L5 vertebrae can be used to determine gender, but these indices are not a good criterion to estimate age and do not have the necessary accuracy to predict the age variable
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